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MINUTES - 05041993 - H.3
H.3 THE BOARD OF SUPERVISORS OF CONTRA COSTA COUNTY, CALIFORNIA Adopted this Order on May 4, 1993 by the following vote: AYES: Supervisors Powers, Bishop, McPeak, and Torlakson NOES: None ABSENT: Supervisor Smith ABSTAIN:None -- -- -- - ---- - - - - - - - -- - -- --- --- - - - -- - - - - - - - - -- - - -- -- - -- - --- - - - -- -- - -- -- - - -- - - - -- - - - - - - -- -- SUBJECT: Hearing on Rezoning Request 2918-RZ, A.J. Salomon/Chartered Land and . Cattle Co.', and Final Development Plan 3032-90, Bethel Island Area. This is the time noticed by the Clerk of the Board of Supervisors for hearing on the recommendation of the East County Regional Planning Commission on the request of A.J. Salomon/Chartered Land, and Cattle Co. (Applicant) and Three Sisters Trust (owner) (2918) for approval to rezone land from General Agricultural District (A-2) and Heavy Agricultural District (A-3) to Planned Unit district (P-1) for 1,330 single family dwelling unit/lots, golf course, school site, fire station, public park, private park area, lakes, channels, drill sites and a surrounding levee, and, for approval of a Final Development Plan (3032-90) for 1,330 lots, golf course, and lake, public park and private recreational area in the Bethel Island area. Dennis Barry, Community Development Department, presented the staff report on the proposed project and commented on the certification of the environmental documentation, approval of vesting tentative map 6562 with conditions, adoption of the mitigation monitoring and reporting program for the project, and adoption of a statement of overriding considerations and findings by the East County Regional Planning Commission on April 5, 1993. Mr. Barry presented the staff recommendation that the Board take testimony today, declare it's intent to approve the rezoning and final development plan, continue the hearing to May 11, 1993 and direct staff to prepare appropriate findings for the Board's consideration on that date. Mitch Avalon, Public Works Department, presented various road issues and the amount of the contribution per unit for the Area of Benefit fee. At the request of Supervisor Torlakson, Mr. Barry further commented on other development in the area. The following persons presented testimony: Patricia Curtin, 279 Front Street, Danville, representing Three Sisters Trust; Ron Heinson, noicard submitted, soils engineer for the project; Bob Gromm, P.O. Box 447, Bethel Island, representing Reclamation District 799; Mary Hudson, no address given, representing Hotchkiss Tract Homeowners Association, presented oral and written testimony; A. Byllar, 4300 Sandmound Boulevard, Oakley; Craig Ogren, 17 Cactus Lane, Oakley; Herbert r. Hern, .1984 Seal Way, Byron; Diane Shipway, P.O. Box 872, Bethel Island; Rhonda Hanson, 4800 Sandmound Boulevard, Oakley; Lynn Dunbar, P.O. Box 165, Newcastle, representing the Archaeological Conservancy; David Pohl, 2639 E. Cypress road, Oakley; Elaine Dannelley, 19 Cactus Lane, Oakley; Fred Davis, 19 Cactus Lane, Oakely; Linda Wadsworth, 4065 Woodhaven Lane, Oakley; Kathryn Dickson, 111 Bear Ridge Trail, Orinda, representing the Sierra club, .j • Greenbelt Alliance and Mt. Diablo Audubon Society; Michael J. McDaniel, 4322 Sandmound Boulevard, Oakley; Katie All, 4384 Sandmound Boulevard, Oakley; Jim Gibson, 100 Howl Avenue, Ste. 155N, Sacramento; A.J. Salomon, no speaker card submitted, applicant. Supervisor Torlakson moved to continue the matter to May 18, 1993, with a ground rule that the Board not hear again from people who have previously testified and that anyone who wishes to submit anything further in writing may do so within a one week period to enable the Board to read. it ahead of time and a tour would be noticed for May 14, 1993, at 3:30. Supervisor Torlakson further directed that staff address issues that had been raised today on matters including the wetlands, the original development recommended on the Del Porto Ranch, landowners in the middle of the project, the library and funding for a new facility, the waiver of park dedication fees and the credit issue, the adequacy of the external levee system, and an affordable housing contribution. Supervisor Bishop seconded the motion. IT IS BY THE BOARD ORDERED that the hearing on the above matter is CONTINUED to May 18, 1993, at 2 p.m. in the Board chambers and staff is DIRECTED to respond to issues raised today as directed by the Board members. I hereby certify that this is a true and correct copy of an action taken and entered on the minutes of the Board of Supervisors on the date shown. cc: Community Development Department ATTESTED: County Counsel PHIL BATCH , Clerk of the Board Public Works Department of rlervips and Co Administrator Chartered Land and Cattle Company By Deputy Ri . 3 A.J. SALOMON/CHARTERED LAND & CATTLE CO. (Applicant) THREE SISTERS TRUST (Owners) County Files #2918-RZ, #3032-90 General Agricultural District (A-2) and Heavy Agricultural. District (A-3) to Planned Unit District (P-1) For purposes of ' compliance with the provisions of the California Environmental Quality Act (CEQA) , an Environmental Impact Report (EIR) has been prepared for this project and will be considered for certification by the Board of Supervisors. Project contains 685.9± acres of land. The site fronts on the east side of Bethel Island Road between Cypress Road and Sandmound Boulevard approximately 2.7 miles east of the town of Oakley. The site is within the area generally called Hotchkiss Tract located south of Bethel Island. The site also fronts on the south side of Sandmound Boulevard east of Bethel Island Road and� on the west side of Sandmound Boulevard north of the proposed Cypress Road extension. BOARD OF SUPERVISORS CONTRA COSTA COUNTY MAY 41 1993 - 2:00 P.M. .r� E Contra BOARD OF SUPERVISORS ' Costant o; FROM: HARVEY E. BRAGDON Count/ DIRECTOR OF COMMUNITY DEVELOPMENT '�� T DATE: April 14, 1993 dsrq Mufti SUBJECT: Hearing on the Cypress--Lakes -Project Rezoning (File- #2918-R2) Preliminary'and Final Development Plan 03032-90) for 1,330 Residential Units Together with a Lake and Channels, 18 Hole Golf Course, Parks, and Other Recreational I Amenities, School Site, Fire Station, Child Care Center, and a Surrounding Levee SPECIFIC REQUEST(S) OR RECOMMENDATION(S) & BACKGROUND AND JUSTIFICATION RECOMMENDATIONS Take testimony on the Cypress Lakes Project, declare intent to: 1. Certify EIR and Addendum; 2. Approve rezoning and preliminary development for the golf clubhouse and driving range, beach club, recreation vehicle and boat storage and day care center and other uses not in Final Development Plan; 3. Approve Final Development Plan for Residential uses, golf course, wetlands, lake, channels and surrounding levee. Continue hearing to the May 11, 1993 hearing and direct staff to prepare appropriate findings. FISCAL IMPACT None. BACKGROUND/REASONS FOR RECOMMENDATIONS On April 5, 1993 the East County Regional Planning Commission certified the Final Environmental Impact Report and Addendum for the Cypress Lakes Project. In addition, the Planning Commission adopted a Statement of Findings and over-riding considerations (Exhibit A) and approved the Mitigation Monitoring Program (Exhibit B) . CONTINUED ON ATTACHMENT: x YES SIGNATURE L _ RECOMMENDATION OF COUNTY ADMINISTRATOR RECOMMENDATION OF BOARD COMMIT E _ APPROVE OTHER SIGNATURE(S) : ACTION OF BOARD ON APPROVED AS RECOMMENDED OTHER VOTE OF SUPERVISORS I HEREBY CERTIFY THAT THIS IS A _ UNANIMOUS (ABSENT - - TRUE AND CORRECT COPY OF AN AYES: NOES: ACTION TAKEN AND ENTERED ON THE ABSENT: ABSTAIN: MINUTES OF THE BOARD OF SUPERVISORS ON THE DATE SHOWN. Contact:Arthur Beresford - 646-2031 Orig: Community Development Department ATTESTED cc: County Counsel PHIL BATCHELOR, CLERK OF Public Works - Mitch Avalon THE BOARD OF SUPERVISORS Applicant/Owner AND COUNTY ADMINISTRATOR BY , DEPUTY 2. The East County Regional Planning Commission also approved Vesting Tentative Map #7562 with conditions (Exhibit C) and adopted findings and exceptions relating to tentative map- (Exhibit. D) .-. The East County Regional Planning Commission recommended that the Board of Supervisors approve Rezoning #2918-RZ and Final Develop- ment Plan #3032-90 with findings (Exhibit E) . The recommended Conditions of Approval for 2918-RZ and Final Development Plan #3032-90 are the same as contained in Exhibit C. The East County Regional Planning Commission recommendation is set forth in the attached resolution (Exhibit F) . The *findings required by CEQA for the Board will be similar to those contained in Exhibit A. The Board may direct changes, if any, to the findings in Exhibit A. Vera Fatooh John Mass John Hotz 5654 Sandmound Boulevard P. 0. Box 264 P. 0. Box 436 Oakley, CA 94561 Knightsen, CA 94548 Bethel Island, CA 94511 Sacramento Planning. . and -Duncan-Simmons Bay Area-Air Quality Mgmt Dist Community Development State Lands Commission 939 Ellis Street 827 Seventh Street, Room 120 1807 13th Street San Francisco, CA 94109 Sacramento, CA 95814 Sacramento, CA 95814 Sierra Club (Diablo Chapter) B. I. Chamber of Commerce Reclamation District #799 21 Anderson Circle 6155 Bethel Island Road Bob Gromm Walnut Creek, CA 94595 Bethel Island, CA 94511 P. 0. Box 447 Bethel Island, CA 94511 Contra Costa Water District City of Brentwood Solano County Department of P. O. Box H2O Planning Department Environmental Management Concord, CA 94524 708 Third Street 601 West Texas Street Brentwood, CA 94513 Fairfield, CA 94533 Department of Fish & Game . Greenbelt Alliance Land Planning Consultants Region 2 116 New Montgomery, Suite 640 239 Main Street, Suite E 1701 Nimbus Road San Francisco, CA 94105 Pleasanton, CA 94566 Rancho Cordova, CA 95760 B. I. Municipal Imp. Assn. Oakley Municipal Adv. Comm. Robert Bond P. 0. Box 244 P. 0. Box 212 Western Area Power Admin. Bethel Island, CA 94511 Oakley, CA 94561 P. 0. Box 3402 Golden, CO 80401 City of Antioch Kathryn Dickson Lyle P. Cohea . P-0. Box 130 1970 Broadway, Suite 1045 2300 Dutch Slough Road Antioch, CA 94509-0504 Oakland, CA 94612 Oakley, CA 94561 Fish & Wildlife Study Comm. Contra Costa Transit Authority Sierra Club (Bay Chapter) c/o Vicki Conklin Pacific Plaza Building 6014 College Avenue Community Development 1340 Treat Blvd., Ste 150 Oakland, CA 94618 Walnut Creek, CA 94596 Rachel M. Baldocchi Rachel M. Baldocchi B.I. Specific Plan Adv. Comm. P. 0. Box 56 P. 0. Box 407 P. 0. Box 860 Knightsen, CA 94548 Bethel Island, CA 94511 Bethel Island, CA 94511 Knightsen Community Council P. G. & E. Antioch Ledger P. 0. Box 170 ATTN: Warren Fuller P. 0. Box 70 Knightsen, CA 94548 1919 Webster Antioch, CA 94509 Oakland, CA 94612 Bethel Island Beacon D. K. Associates National Audub6n Society P. 0. Box Drawer 580 1440 Marie Lane, Suite 200 Mt. Diablo Chapter Bethel Island, CA 94511 Walnut Creek, CA 94596 P. 0. Box 53 Walnut Creek, CA 94596 -Contra Costa Historical Society U.S. Fish & Wildlife-Service - -Linda Pratt 1700 Oak Park Blvd., Room C5 Sacramento Field Office EBRPD Pleasant Hill, CA 94523 2800 Cottage Way, Room E-1803 11500 Skyline Blvd. Sacramento, CA 95825 Oakland, CA 94619 Oakley Fire Protection District Oakley Water District USDA Soil Conservation Service P. 0. Box 207 27 Main Street c/o Larry Soenen Oakley, CA 94561 Oakley, CA� 94561-- 5552 Clayton Road Concord, CA 94521 Brentwood News Three Sisters Trust Citizens to Preserve the Delta P. 0. Box 517 101 Ygnacio Valley Rd, Suite 400 P. 0. Box 821 Brentwood, CA 94513 Walnut Creek, CA 94596 Brentwood, CA 94513 American Indian Councis, Inc. San Joaquin Planning Dept. Contra Costa Mosquito 2122 Emrick Avenue 1810 E. Hazelton Avenue Abatement District San Pablo, CA 94806 Stockton, CA 95205 155 Mason Circle Concord, CA 94520 Bethel Island Fire Prot. Dist Liberty Union H. S. Dist. ABAG, P. 0. Box 623 350 Second Street P. 0. Box 2050 Bethel Island, CA 94511 Brentwood, CA 94513 Oakland, CA 94604 Charter Land & Cattle Co. Public Affairs Management Calif. Native Plant Society 101 Ygnacio Valley Road, Ste 400 ATTN: Scott Steinwert , P. 0. Box 5597 Walnut Creek, CA 94596 101 The Embarcadero, Ste 210 Elmwood Station San Francisco, CA 94105 Berkeley, CA 94704 Citizens Land Alliance U.S. Army Corps of Engineers Delta Advisory Council 340 W. Grantline Road 650 Capitol Avenue c/o C. Zahn Tracy, CA 95376 Sacramento., CA 95814 Community Development Oakley Sanitary District Oakley Union School District 032-020-014 P. 0. Box 1105 Norcross Lane Clarence C. Lopes Oakley, CA 94561 Oakley, CA 94561 4277-4282 Knightsen Avenue Oakley, CA 94561 032-020-006 032-010-001, 002 032-040-014, 15 James & Bonnie Owen Baldocci Family Trust Stuart Erskine Rt. 2, Box 189 Route 2, 6390 Sellers Ave. Rt. 1, Box 194 Oakley, CA 94561 Oakley, CA 94561 Knightsen, CA 94548 032-040-031 032-040-037 032-060-001 William & Dora Valentine Leo Hodges Arley & Mary Reeves 20 Broadway St. 20020 Sherman Isle Levee Rd E 2109 E. Cypress Rd Oakley, CA 94561 Rio Vista, CA 94571 : Oakley, CA 945.61 032-060-004 032-060-008 032-060-011 Donald & Barbara Darst Lloyd & Louise Smalley Ruth Bloodworth 2181 D. Cypress Rd Rt. 2, Box 214 3990 Holmes Rd. Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-060-013 032-060-017 031-040-016 Zetta Reynolds Fannie Caruthers Lupe Martinez 2331 E. Cypress Raod 2461 Cypress E. Rd 1631 East Cypress Rd. Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-040-032 032-040-048 032-060-002 William & Kerry Koenig Jen Thayer Gary & Joni Woodworth 4312 Redwood Dr. 1541 E. Cypress Rd. 2131 E. Cypress Rd. Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-150-005, 6, 7, 12 032-060-007 032-060-009 David & Delorea Wollaston Emma Jackson Frank & LaRee Montero P. 0. Box 230 P. 0. Box 752 Rt. 2, Box 215 Bethel Island, CA 94511 Bethel Island, CA 94511 Oakley, CA 94561 032-060-012 032-060-014 032-060-018 Vincent & Maxine Friedman William & Gay Martins Robert & Sandra Feit 1215 Chianti Way P. 0. Box 331 Rt. 2, Box 218-AA Oakley, CA 94561 Bethel Island, CA 94511 Oakley, CA 94561 032-040-017 Occupant 032-050-002 Ruben & Maria Paez 1771 Cypress Road E. 032-092-001 201 Cypress Rd. Oakley, CA 94561 David & Kelly Dal Porto Oakley, CA 94561 2121 Colonial Court Byron, CA 94514 David Dal Porto 032-060-003 032-060-005 Rt. 2, Box 234 Thomas Cole Charles & Patricia Foster Oakley, CA 94561 Rt. 2, Box 210 2191 E. Cypress Road Oakley, CA 94561 Oakley, CA 94561 Occupant 032-060-010 Occupant 2221 E. Cypress Road Gary Larsen 2311 E. Cypress Rd. Oakley, CA 94561 2271..E. Cypress Road Oakley, CA 94561 Oakley, CA 94561 032-060-016 032-060-019 032-070-001 Jessie & Evelyn Bagwell Doug & Marlos Hicks Henri Aupiffred 2441 E. Cypress Road 2401 E. Cypress Rd. 2491 E. Cypress Rd Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-070-007 032-070-010, 011 032-070-019 Tim & Barbara Burnett Isaac & Lillian Smith Patrick & Pamela Kiernan 2619 Cypress Rd. 2689 Cypress Road 2947 E. Cypress Road Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 945,61 032-081-008 032-091-001 032-091-004 Bruce Burroughs Evelyn Walker Guy Eggum 22323 E. Monte Vista Ave 2061 Buena Vista #13 P. 0. Box 6491 Denair, CA 95316 Alameda, CA. 94501 Concord, CA 94524 032-092-005 032-100-004, 23 Occupant Albert & Mary Wilanes Leo & Mary Cunha 2358 Dutch Slough Rd 417 Hemlock Avenue P. 0. Box 3645 Oakley, CA 94561 S. San Francisco, CA 94080 Antioch, CA 94509 032-070-002; 3, 4 032-070-008 032-070-022 Thomas & Mary Meredith David & Laurie Pohl Hugh & Nancy Ferguson Rt 2, Box 221 2639 Cypress Raod 2879 E. Cypress Rd. Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-081-010 Occupant 032-091-006 Mark Gilbert 1800 Dutch Slough Rd Maxie & Elma Walker Rt. 2, Box 481 Oakley, CA 94561 P. 0. Box 824 Oakley, CA 94561 Oakley, CA 94561 032-100-005 032-100-007 032-070-005, 6 Frank Nicoletti Patrick & Martha Fitzpatrick Floyd & Patricia Dudgeon Rt. 2, Box 206 E P. 0. Box 203 P. 0. Box Bi Brentwood, CA 94513 Bethel Island, CA 94511 Bethel island, CA 94511 032-070-009 032-070-018 032-070-023 Homer & M.artha War.bington L. D. & Francess Frigard Michael & Sheila Quintana 2667 Cypress Rd. E. 2921 E. Cypress Rd 2901 E. Cypress Rd. Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-091-003, 5 032-092-001, 2 032-100-001 Robert Gromm Anthony Cerelli Jim & Linda Biles P. 0. Box 447 P. 0. Box 876 2314 Dutch Slough Rd. Bethel Island, CA 94511 Oakley, CA 94561 Oakley, CA 94561 032-100-006 032-100-008 Occupant Ed & Donna Meagor Clayburn Dowell Trust 2376 Dutch Slough Rd. 20 Meadow Avenue c/o Mark Layfeld Oakley, CA 94561 San Rafael, CA 94901 46 Orinda Circle Pittsburg, CA 94565 032-100-016 032-100-019 Occupant John Chambers Francis Bertholic 2330 Dutch Slough Rd 655 Discovery Bay Blvd. P. 0. Box 402 . Oakley, CA 9456.1 Byron.' CA 94514 Bethel Island, CA 94511 j=' 032-120-003, 4, 13, 17 032-120-010, 11, 12 7 6 Raymond & Shirley Zurfluh John Robles :.a:< 6n r financial 2616 Buena Vista Avenue Rt. 2, Box 412 P. pox 1458 Walnut Creek, CA 94596 Oakley, CA 94561 Pittsburg, CA 94565-0458 032-130-009, 10, 11 , 12, 22 032-1.40-002 .032-100-014, 30, 31 Joseph & Julia Spotts 032-150-001 Eric Sproule/Patricia Valenti P. 0. Box I Troy & Sandra Peterson 2432 Dutch Slough Rd Bethel Island, CA 94511 P. 0. Box 314 Oakley, CA 94561 Bethel Island, CA 94511 032-100-017 032-100-021 032-100-026, 27, 28, 29 Walter Peer Steven & Janet Chalk Patrick & Patricia Watson 2470 Dutch Slough Rd 442 Cornish Court 1219 Stirling Drive Oakley, CA 94561 Oakley, CA 94561 Rodeo, CA 94572 032-120-001, 18 032-120-005, 14, 15, 16 032-130-001 James & Shirley Wong Ruth Law Timothy & Sarah Betts P. 0. Box 161 P. 0. Box 1 109 2780 Dutch Slough Rd Bethel Island, CA 94511 Bethel Island, CA 94511 Oakley, CA 94561 032-130-003 032-130-016, 18, 19 032-140-005, 14 William Lee Michael McNamara Dale & Jerrilyn Hennis 2800 Dutch Slough Rd P. O. Box 1 150 P. 0. Box M Oakley, CA 94561 Bethel Island, CA 9.4511 Bethel Island, CA 94511 032-100-015 032-100-018 Occupant Ralph Behneman Bill & Joan Brewer 2414 Dutch Slough Rd Rt 2, Box 449A P. 0. Box 442 Oakley, CA 94561 Oakley, CA 94561 Bethel Island, CA 94511 032-120-002 032-120-006, 7, 8, 9 032-130-002 Harvey & Rae Craig Elmo & Margarethe Wurts Viola Hayes 2662 Dutch Slough Rd P. 0. Box G c/o Jackie Skrehot Oakley, CA 94561 Bethel Island, CA 94511 2792 Dutch Slough Oakley, CA 94561 032-130-008 032-130-020, 21 032-140-010, 032-230-017 032-240-004 Michael & Gay Ganson 032-182-005 David Hernandez P. 0. Box 803 Glenn & Marilyn Frizzell 4580 Sandmound Blvd ! Oakley, CA 94561 3892 Sophist Drive Oakley, CA 94561 San Jose, CA 95132 032-140-012, 15 032-150-003 032-150-009 Marshal Mirza Howell Morgan Jeffrey & Jacqueline Stuelke P. 0. Box 536 611 Victoria Court P. 0. Box 445 Bethel Island, CA 94511 San Leandro, CA 94577 Bethel Island, CA 94511 032-171-006 032-172-004 Occupant John Bullene Barbara Field 5600 Sandmound Boulevard 5543 Sandmound Blvd 5628 Sandmound Blvd Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-172-012 032-172-016 032-172-022 Christian Sanders William & Ingrid Glover George Garcia 5558 Sandmound Boulevard 253 Manley Court P. 0. Box 984 Oakley, CA 94561 San Jose, CA 95239 Bethel Island, CA 94511 032-181-005 - 032-150-002 - Occupant . Russell & ELise Allen Gerald & Marcia Hooper 3275 Wells Road P. O. Box 1121 397 Lagunita Drive Oakland, CA 94561 Bethel Island, CA 94511 Soquel, CA 95073 032-171-004 032-171-008, 9 032-172-005 Albert & Palmira Padilla Gary & Martha Willson Walter & Virginia Pierce P. O. Box 812 ' 2 Corte Del Bayo P. 0. Box BH Bethel Island, CA 94511 Larkspur, CA 94939 Bethel Island, CA 94511 032-172-007 032-172-013 032-172-020 Donald Piantanida Richard Genton Walter Thompson Rt. 2, Box 370 5544 Sandmound-Boulevard 18165 Standish Avenue Oakley, CA 94561 Oakley, CA 94561 Hayward, CA 94541 032-181-003 032-181-006 Occupant Milton & Beverly Ng George Fong 3265 Wells Road Rt. 2, Box 366 5492 Sandmound Blvd. Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-150-004, 13,'14 032-171-005 032-172-002 Pete & Ethel Torniello Conn Findlay Hary Hartnack P. 0. Box 668 . 3123 Willow Rd. 350 Shaw Rd. Bethel Island, CA 94511 Antioch, CA 94509 Walnut Creek, CA 94596 032-172-006 032-172-010, 11 032-172-014 Ron & Linda Wadsworth 032-181-002 James & Barbara Reynolds 4065 Woodhaven Lane Marvin & Ruth DeBerg 5540 Sandmound Boulevard Oakley, CA 94561 3818 Quigley St. Oakley, CA 94561 Oakland, CA 94619 032-172-021 032-181-004 032-181-007 James & Judy Barton James & Marilyn Hopwood Andrew & Marion Leong 5656 Sandmound Blvd. Rt. 2, Box 364 566 Commercial St. Oakley, CA 94561 Oakley, CA 94561 San Francisco, CA 94111 032-181-009 032-181-012 032-181-019 Timothy & Katheine Medzius Reiner & Mary Uenigk Gloria Sciabich 5468 Sandmound Boulevard 2103 Cornet Boulevard 1296 Madera Way Oakley, CA 94561 Belmond, CIA 94002 Millbrae, CA 94030 032-181-022 032-181-024 032-182-002 John & Judith Dunn Edward & Earlene Schader Jack & Sharon Strickland Rt. 2, Box 359A P. 0. Box 28 Rt. 2, Box 365 Oakley, CA 94561 Bethel Island, CA 94511 Oakley, CA 94561 032-181-001 032-181-008, 10 032-181-011 032-182-001 Robert & Claudia Paxton Carlos & Gloria Virmontes Marvin & Ruth DeBerg 3330 Seldon Court 2185 San Rafael Avenue 3818 Quigley Street Fremont, CA 94538 Santa Clara, CA 95051 Oakland, CA 94619 Occupant 032-181-014 . . . Occupant 5444 Sandmound Boulevard Ron & Nancie Westhorpe 5382 Sandmound Blvd. Oakley, CA 94561 Rt. 2, Box 361 E Oakley, CA 94561 Oakley, CA 94561 032-181-023 032-181-025 032-182-003 K. Macht Michael Frey Willie & Lolita Gann 6759 Bret-Harte Dr. 2252 Calle Del Mundo. Rt. 2, Box 363 San Jose, CA 95120 Santa Clara, CA 95051 Oakley, CA 94561 Occupant Occupant 032-181-013 5476 Sandmound Blvd. 5452 Sandmound Blvd. Giles Leung Oakley CA 94561 Oakley, CA 94561 5436 Sandmound Blvd. Oakley, CA 94561 032-181-015, 16, 17, 18 032-181-020, 21 Occupant Arthur Mirassou Hubbard Family Trust 5346 Sandmound Blvd. 1655 Bluebell Dr. 5374 Sandmound Blvd. Oakley, CA 94561 Livermore, CA 94550 Oakley, CA 94561 032-181-027 032-182-004 032-182-006 Robert & Shirley Wray William Slater Floyd & Olive O'Brien 10451 Lindsay Ave. P. 0. Box 1261 5445 Sandmound Boulevard Cupertino, CA 95014 Bethel Island, CA 94511 Oakley, CA 94561 032-182-009 032-182-012 032-191-001 Darrel & Marceline Edwards Alfonso & Alicia Guttron Robert Wieger 5395 Sandmound Boulevard I 5361 Sandmound Boulevard 5324 Sandmound Boulevard Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-191-005, 46 032-191-010 032-191-013 Allan & Agda Weber Donald & Michele Shewmaker Margaret Fickert 354 Orchard Avenue i 5236 Sandmound Boulevard 95 Moneta Way Sunnyvale, CA 94086 Oakley, CA 94561 San Francisco, CA 94112 032-191-017 032-191-022, 39 Occupant George Leydecker i Allen & Lillian Dale 5116 Sandmound Boulevard 5172 Sandmound BoulevA P. O. Box295 Oakley, CA 94561 Oakley, CA 94561 Bethel Island, CA 94511 032-182-007 032-182-010 032-182-013 Myrna Webster I. Larry & Deborah Gardner Mark & Sandra Carter 401 Viewrnont 5383 Snadmound Boulevard P. 0. Box 1320 Benicia, CA 94510 Oakley, CA 94561 Bethel Island, CA 94511 032-191-004 032-191-006 032-191-011 Ron & Carolyn Lai Mark & Cynthia Glenn Daniel Turcotte 538 - 6th Street 5274 Sandmound Boulevard Rt. 2, Box 710 San Francisco, CA 94118 Oakley, CA 94561 Brentwood, CA 94513 032-191-014 032-191-018 032-191-023 032-191-041 Joseph Bergeron Reginald Dunning Terry & Deborah Lee 14486 Jasper Lane 5124 Sandmound Boulevard 5200 Sandmound Boulevard Grass Valley, CA 95945 Oakley, CA 94561 Oakley, CA 94561 032-191-025 032-182-008 032-182-011 Alan & Martha Tindall Corrine Reynolds Elvezia Gibson 2189 Queens Lane 1830 St. George Rd 8735 Bainbridge Place San Mateo, CA 94402 Danville, CA 94526 Stockton, CA 95209 032-182-014 Occupant 032-191-007, 42 Richard & Katherine Moser 5296 Sandmound Boulevard Charles & Shirley Kissick Rt. 2, Box 358A Oakley, CA 94561 5266 Sandmound Boulevard Oakley, CA 94561 Oakley, CA 94561 032-191-012 032-191-015 032-191-019 Harriett Abraham John & Carrie Morgridge Almon & Patricia Anglin 5220 Sandmound Boulevard 3980 S. Peardale Dr. 5156 Sandmound Boulevard Oakley, CA 94561 Lafayette, CA 94549 Oakely, CA 94561 032-191-024 Occupant 032-191-030 Terry & Clarice Haschert 5108 Sandmound Boulevard Howard & La Faye Smith 7609 Driftwood Way Oakley, CA 94561 5252 Sandmound Boulevard Pleasanton, CA 94588 Oakley, CA 94561 Occupant 032-191-052 032-192-004 5148 Sandmound Boulevard Edmund & Sally Langes Joseph & Hiroke Romero Oakley, CA 94561 5176 Sandmound Boulevard P. 0. Box 156 Oakley, CA 94561 Oakley, CA 94561 032-192-008 032-192-011 Occupant Donald Rhyne Carlos Guzman 5115 Sandmound Boulevard P. 0. Box 681 5161 Sandmound Boulevard Oakley, CA 94561 Bethel Island, CA 94511 Oakley, -CA 94561 032-201-003 Occupant 032-201-008, 25 Alvin & Nancy Hillelane 5054 Sandmound Boulevard William & Joellyn Rinnander 752 Hilton Road Oakley, CA 94561 901 Daisy Street Walnut Creek, CA 94595 San Mateo, CA 94401 032-191-036 032-191-048, 50 032-192-001, 2 Dolores Hicks Donald & Carlette Butler Delta Mutual Water Co. P. 0. Box 635 2 Whitt Court P. 0. Box 607 Bethel Island, CA 94511 Clayton, CA 94517 Oakley, CA 94561 032-192-005 032-192-009 032-192-012 Michael & Paula Stead Mark & Lynn LaLiberte Gordon & Jackie Jennings 5265 Sandmound Boulevard 5187 Sandmound Boulevard P. 0. Box 24 Oakley, CA 94561 Oakley, CA 94561 Bethel Island, CA, 94511 032-201-001 032-201-004, 5 -032-201-007i 23 Evelyn Scanlon Donald & Deanna Crane Robert & Carol Daugherty 5096 Sandmound Boulevard 5070 Sandmound Boulevard 24 Warford Terrace Oakley, CA 94561 Oakley, CA 64 561 Orinda, CA 94563 Occupant 032-191-047 043-191-051 5038 Sandmound Boulevard James & Cleo Williams Gerald & Irma Sauberan Oakley, CA 94561 4303 Amber Foil Avenue 5148 Sandmound Boulevard Oakland, CA 94605 Oakley, CA 94561 032-192-006, 7 032-192-010 032-192-014 Agustin Gurule Robert & Priscilla Myers Robert Sherman 5243 Sandmound Boulevard j 5175 Sandmound Boulevard P. 0. Box 671 Oakley, CA 94561 Oakley, CA 94561 Brentwood, CA 94513 032-201-002 032-201-006 Occupant Ken & Ethel Doll Merwyne & Sheila Schafer 5046 Sandmound Boulevard P. 0. Box 286 25176 Ave. 5% Oakley, CA 94561 Bethel Island, CA 94511 Madera, CA 93537 032-201-011 032-201-012 032-201-015 Robert & Sandra Gann Martin Logan William & Dorothy Neuman 5014 Sandmound Boulevard 5000 Sandmound Boulevard 4976-Sandmound Boulevard Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-201-018 032-201-021 032-201-024 Albert & Angelina Gauazza Stanley & Roberta Faria Robert & Joyce Eakle 518 LaMancha Court 1910 Lomita Drive 348 Waverly Street Danville, CA 94526 San Leandro, CA 94578 Menlo Park, CA 94025 032-201-013 032-201-016 032-201-019 Douglas & Merrilee Weber William & Hazel Muffett Barbara LaFargue 4992 Sandmound Boulevard P. 0. Box 836 4300 Sandmound Boulevard Oakley, CA 94561 Bethel Island, CA 94511 Oakley, CA 94561 032-201-022 Occupant 032-201-014 Harry Jennings 4094 Sandmound Boulevard Charles & Lydia Clenahan P. 0. Box 374 Oakley, CA 94561 16928 Kennedy Raod Bethel Island, CA 94511 Los Gatos, CA 95030 032-201-017 032-201-020 032-201-023 Frank DeMello Hulori & Patricia Thomas Doris Anderson 5210 San Pablo Dam Rd. Rt. 2, Box 341 B 1588 Cottle Avenue El Sobrante, CA 94803 Oakley, CA 94561 San Jose, CA 95125 032-201-030, 29 032-202-001 032-202-004 Ernest Brown Danny & Beverly Wyman Robert & Brenda Galindo 5022 Sandmound Boulevard 5093 Sandmound Blvd 1810 Beringer Way Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-202.-006 032-202-009 032-240-019 E. V. & Drusilla Woolever Jerry & Cindy Whitener James Brannigan Rt. 2, Box 34813 Rt. 2, Box 343 Rt. 2, Box 305 Oakley, CA 94561 Oakely, CA 94561 Oakley, CA 94561 032-240-022 032-240-026 032-240-029 Paul & Carol Omelich Gus & Mary AAn Burkholtz Allan & Gerda Robbins 3804 Harbor Street 4392 Sandmound Boulevard Rt. 2, Box 300A Pittsburg, CA 94565 Oakley, CA 94561 Oakley, CA 94561 032-240-032 032-202-002 Occupant Robert Council Philip Murphy 5035 Sandmound Boulevard 4330 Sandmound Boulevard 5075 Sandmound Boulevard Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-202-007 032-202-010 032-240-020 Richy Oxford Milo & Rama Allen Michael & Janet McClery 112 DeNormandie Way Rt. 2, Box 341 C 1163 Pulora Court Marinez, CA 945.53 Oakley, CA 94561 Sunnyvale, CA 94087 032-240-023 032-240-025 032-240-027 Richard & Heide Marie Patterson Joseph & Ralette Blaettler Guy & Mary All 4420 Sandmound Boulevard P. 0. Box 44209 4384 Sandmound Boulevard Oakley, CA 94561 Cincinnati, OH 45244 Oakley, CA 94561 032-240-030 032-280-001, 15 032-202-003 Morgan & Kathryn Fong Woodrow & Geneva Robinson Jay & Elva McCrary 872 Union Street 3917 Cinnabar Street 5057 Sandmound Boulevard San Francisco, CA 94133 Antioch, CA 94509 Oakley, CA, 94561 032-202-005 032-202-008 032-240-017 Ron & Marcia Trotter Petr & Diane Smith William & Bruna Seib 5027 Sandmound Boulevard P. 0. Box 3724' 185 Angelita AVenue Oakley, CA 94561 Olympic Village; CA 94730 Pacilica, CA 94044 032-240-021 032-240-024 Occupant Alice Gardner Frank Serrano 4400 Sandmound Boulevard Berkeley Marina 45 4412 Sandmound Boulevard Oakley, CA 94561 Berkeley, CA 94710 Oakley, CA 94561 032-240-028 032-240-031 032-280-002 Charles & Terrie Rowland Lenko & Clara Gazija Elizabeth Wells Route2, Box 3008 913 Hawthorne Avenue 3819 La Miranda Place Oakley, CA 94561 Antioch, CA 94509 Pittsburg, CA94565 032-230-029, 34 032-230-036 032-240-003 032-240-001 Ken & Jacqueline Carver Steven & Linda Musich Dale Wong 4850 Sandmound Boulevard 17655 Tourney Road 4616 Sandmound Boulevard Oakley, CA 94561 Los Gatos, CA 95032 Oakley, CA 94561 032-240-005 Occupant 032-240-009 Charles & MaryAnn Salsberry 4564 Sandmound Boulevard Phillip & Jenita Dick 2290 Lindaire Avenue Oakley, CA 94561 2786 Halcyon Drive San Jose, CA 95128 San Leandro, CA 94578 032-240-038 032-280-009 03Y-290-001, 2 Oakley Mutual Water Co. Jonathan Scheitel John & Treva Hingston P. 0. Box 1346 P. 0. Box 151 Rt. 2, Box 239 Oakley, CA 94561 Byron, CA 94514 Oakley, CA 94561 032-340-002 Occupant 032-240-007 Eva Zouzounis 4572 Sandmound Boulevard Harold Altschuler 1348 W. K Street Oakley, CA 94561 4550 Sandmound Boulevard Benicia, CA 94510 Oakley, CA 94561 Occupant 032-240-042 032-280-036 4534 Sandmound Boulevard Richard Kent Brian Walker Oakley, CA 94561 P. 0. Box 648 P. 0. Box CB Bethel Island, CA 94511 Bethel Island, CA 94511 032-290-003 Occupant 032-230-040 Glen Brooks 3611 E. Cypress Road John & Audrey O'Keefe 4330 Grammercy Lane Oakley, CA 94561 4882 Sandmound Blvd Concord, CA 94520 Oakley, CA 94561 032-240-002 032-240-006 032-240-008 Ron Smith Theodore & Deanna Robinson William & Barbara Senior 4600 Sandmound Boulevard 544 Sycamore Road 152 - 29th Avenue Oakley, CA 94561 Pleasanton, CA 94566 San Mateo, CA. 94403 032-240-010, 46 032-240-045, 18 032-280-037 Raymond & Diane Shipway Ken & Neva Simon Delta Real Estate Corp. P. 0. Box 872 4486 Sandmound Boulevard P. 0. Box 96 Bethel Island, CA 94511 Oakley, CA 94561 Bethel Island, CA 94511 032-330-010 032-340-004 032-082-004 Robert & Elizabeth Sandlin Donald & Eileen Shell Timothy Chen 263 Circulo Tierra 1526 Willow Pass Road, #38 3835 Buell Street Rohnert Park, CA 94928 Pittsburg, CA 94565 Oakland, CA 94612 032-082-008, 9 032-220-002 032-220-029 032-040-046 Carol Ann Coleman Craig & Deborah Ogren Lars & Christina Delin 3150 E. Cypress Road 17 Cactus Lane 36 Broadmoor Court Oakley, CA 94561 Oakley, CA 94561 San Ramon, CA 94583 ' , O32-��O�)11 ' 1�, 1� 14 Occupant ���-���+D�5 ' Stewart Enterprises Launs [Jeaohonmp 4734Sandrnound Boulevard 4Buena Vista Drive 4778 Sondnnound Boulevard Oakley, CA 84561 Danville, CA 94528 Oakley, CA 94581 ' 032-230-019 032-230-023 032-330-025 Nicholas Hayes Ken Rawlings Alto Ferrell ' 155 San FEdmpeWay 4l2Scenic Avenue 4138Lillian Drive San Francisco, CA 94127 Piedmont, CA 84611 Concord, CA 94521 Occupant 032-082-005, 78 {}3f-O82-01O 4656Sondmnound Boulevard OaanLemher Saynmoor8rosa Oakley, CA 94561 8Sally Ann Road 1284SAshley Court Orinda, CA 94563 Saratoga, CA 95070 ' Fred Davis 032-220'030 (}32-230f009 19 Cactus Lane Elaine DanneUay VViUiarn & Nancy Sherwood Oakley, C/\ 94581 Rt 2, Box 226C 4818 SandmmVund Boulevard Oakley, CA 94561 Oake\y' CA 94561 032-230-015 032-230-018 032-330'020 Brainard 8k Margaret Duffield Howard & J. R. 04oUenhopf John & Lisa JUnem Rt' 2, Box 331 320 Laurel Avenue 47(}0 Sandnnound Boulevard Oakley, CA 94561 Son Anoe|nno' CA 94380 Oakley, CA 94561 Occupant 032-230-026' 27 032-082+006 4672 Sandnnound Boulevard Richard Kent Ore|an 8, Betty Adams Oakley, CA 94581 4648 Sandmound Boulevard P. D. Box 811 Oakley, CA 94561 [}ak|ay' C/\ 84581 032-202-011 032-230-0X04 032-230-010' 35 David & Lorraine Henderson Fred & Carolyn Botkin John 8, Rhonda Hanson P. C>' Box 1319 42022 Road #114 Rt' 2' Box 335 Bethel Island, CA 94511 Oinuba' CA 83618 . Oakley, CA 94561 032-230-010, 35 032'230-016 Occupant John & Rhomja Hanson Robert Schaefer 4720 Sondrnound Boulevard 4800 GandnnVund Blvd 4742 Sandnnound Boulevard Oakley, CA 94561 Oakley, CA 94561 OaNey, CA 94561 032-230-021 , 22' 38 033'330-024' 37 032-230{)28 David Bit1|e Otto & Kath VVoo|fa\ ' Raynmond1Giarnusso - 2534 Maywood \ 4864.Sondnnound Boulevard 3120 Camino Diablo San Jose, CA 95128 Oakley, CA 94561 Byron, CA 94514 032-280-003 032-280-0]8 032-280-013 Jay Collins Gloria A|arnio Shirley Cottrell 1400 Canymnvvood Court' #3 132 Pelican Loop 5332 Tule Tree Lane Walnut Creek, CA 94595 Pittsburg, CA 94565 Oakley, CA 94561 032-280-022 032-280-026 032-280-035 Gregg & Paula Nordine Arthur Murillo James & Patricia Reedy 3500 Sandmound Boulevard i P. 0. Box 1007 Rt. 2, Box 238 Oakley, CA 94561 Pittsburg, CA 94565 Oakley, CA 94561 032-300-001 032-300-003 032-300-010, 1-1 James & Pauline Zimmerman Duane & Arlene Henry Darrell & Marceline Edwards 6687 Leyland Park Drive Rt. 2, Box 293 4292 Sandmound Boulevard San Jose, CA 95120 Oakely, CA 94561 Oakley, CA 94561 032-311-006, 7 Occupant 032-280-011 Steven Priddy 3550 Sandmound Boulevard Ellis Sidney -P. 0. Box 296 Oakely, CA 94561 5360 Tule Tree Lane Oakley, CA 94561 Oakely, CA 94561 032-280-014 032-280-024 032-280-032 James & Elizabeth Williams James & Hazel Allen Robert & Carol Joaquin 5320 Tule Tree Lane 3490 Sandmound Boulevard Rt. 2, Box 240 Oakley, CA 94561 Oakley, CA 94561 Oakley, CA 94561 032-280-038, 39 Occupant 032-300-007 Betty Bunting 1 4312 Sandmound Boulevard James & Sandra Aberer P. 0. Box 465 Oakley, CA 94561 P. 0. Box 643 Behtel Island, CA 94511 Diablo, CA 94528 032-311-002, 3, 4 032-312-002, 3, 4 032-280-006 Ralph. Lasky Evan & Trudy Barbieri William Navas c/o Red Carpet Realtors 1326 Chorro Street c/o P. & E. Stutsman Trust 2900 S. Highland Bldg., 18D San Luis Obispo, CA 93401-4006 555 Heather Way Las Vegas, NV 89109 San Rafael, CA 94903 032-280-012 032-280-019 032-280-025 William & Treva Fortner Larry & Geogina Thompson Scott & Charlotte Beiswanger- P. 0. Box 477 11148 County Road 34 5372 Tule Tree Lane Bethel Island, CA 94511 j Mancos, CO 81328 Oakley, CA 94561 032-280-034 032-280-040 032-300-002 Carl & Melba Jackson Kilye Chaekal Michael Buller/Barbara La Fargue Rt. 2, Box 962 5390 Aspen Road 4300 Sandmound Boulevard Brentwood, CA 94513 Oakley, CA 94561 Oakley, CA 94561 032-300-009 032-300-009 032-311-005 Clara Marshall Clara Marshall 032-312-001 4303 Sandmound Boulevard' 2445.Greentree James & Joan Zischke Oakley, CA 94561 Salem, OR 97305 239 Villa Manzanal Aptos, CA 95003 032-330-001, 6, 16, 17 032-340-005 032-340-008 Sam & Mary Orona Alan & Paula Goings Steve & Elizabeth Kurtz 1615 Geyser Circle P. 0. Box CL Rt. 2, Box 2548 Antioch, CA 94509 Bethel Island, CA 94511 Brentwood, CA 94513 020-140-007 032-340-006 032-340-009 020-150-003 Billie & Barbara Lively Lawrence & Kin Rocconi Edward Biggs P. 0. Box 517 P. 0. Box 215 . 3793 Towns Court Oakley, CA 94561 Oakley, CA 94561 Pinole, CA 94564 020-150-002 032-340-007 032-340-011 Jeffrey Coyne Tawana Borge Michael McDaniel 1528 20th Street 105 Brock Lane P. 0. Box 1280 Santa Monica, CA 90404 Oakley, CA 94561 Oakley, CA 94561 032-330-003 033-011-010 033-012-005 Agenes Harris Roger & Robin Proctor Gilbert & Eloisa Ruiz 2060 Asilomar Drive 26312 N. Jacktone Road 211 E. Cypress Road Oakland, CA 94511 Gait, CA 95630 Oakley, CA 94561 033-020-011 033-030-022 033-160-023 033-160-038 Patricia Fraser Harding & Peggy Van Brunt Paulino & Andrea Hojas 1320 N. Manzanita P. 0. Box 1021 509 2nd Street Orange, CA 92667 Oakley, CA 94561 .Antioch, CA 94509 .033-180-006 033-190-003 033-250-002 John Askins James & Doris Cosetti James & Marcia Nabas Rt. 2, Box AA 386 3324 Fraser Road 113 Old Oak Court Oakley, CA 94561 Antioch, CA 94509 Oakley, CA 94561 Occupant 032-330-023 033-012-002 2600 Dutch Slough Road Viola Hayes 037-192-013, 14 Oakley, CA 94561 c/o Jackie Skrehot GonsIves & Santucci, Inc. 29 Weller Court 5152 Port Chicago Highway Pleasant Hill, CA 94523 Concord, CA 94520 033-012-008 Occupant 033-160-021 John & Rhunett Surney 4151 Madrado Lane Ike & Ruby Machado 6 Vista Diablo Oakley, CA 94561 P. 0. Box 511 Pittsburg, CA 94565 Oakley, CA 94561 033-180-014 033-240-008 033-250-003 Bernice Hoyt William & Sheil Elliott John & Ilene Hampton P. 0. Box 1299 1601 Tennessee Street P. 0. Box 114 Oakley, CA 94561 Vallejo, CA 94590 Oakley, CA 94561 032-330-018 032-351-081 033-012-004 Contra Costa San Dist #15 032-362-010, 12 -Sam & Marie Jung Ironhouse Sanitary Dist Willow Park Marina H/O Assn. 49 Saturn Street P. O. Box 1105 P. 0. Box 406 1 San Francisco, CA 94114 Oakley, CA 94561 Bethel Island, CA 94511 Occupant 033-030-020 033-160-022 251 E. Cypress Road Wade Loo David & Linda White Oakley, CA 94561 2803 San Ardo Way P. 0. Box 769 Belmont, CA 94002 Oakley, CA 94561 033-180-001 033-190-001 033-250-001 Richard Swanson Manuel & Cecilia Peixoto Thomas & Melinda Arney 821 E. Cypress Road Rt. 2, Box 387 117 Old Oak Co'urt Oakely, CA 94561 Oakley, CA 94561 Oakley, CA 945.61 033-250-004 033-260-003 - 033-271-073 Donald & Marcia Lopez Ron & Jean Ann Davi Quail Valley Estates Owners Assn 103 Old Oak Court 4000 Meadows Lane c/o Boardwalk Associates Oakley, CA 94561 Oakley, CA 94561 1425 Treat Boulevard, #B Walnut Creek, CA 94596 033-302-027 037-192-012 033-2607004 Tract #6922 H/O Assn Don;ld Williamson Partnership Horace & Norrine Siino 395 Taylor Blvd, #120 Rt. 1 , Box 1115 2335 Fairview Avenue Pleasant Hill, CA 94523 Antioch, CA 94509 Brentwood, CA 94513 Quail Valley Estates Owners Assn; 035-282-030 Occupant 612 Railroad Avenue, #4 Leon & Ruth Mullins 240 E. Cypress Road Brentwood, CA 94513 4701 Tobi Drive Oakley, CA 94561 Concord, CA 94521 033-260-008 033-302-026 037-192-001 , 2 John & Ivette Vanderburgh Oakley Associates Emerson Dairy 4000 Creekside Court c/o Wooldridge Const. Route 2, Box B-384 .Oakley, CA 94561 395 Taylor Boulevard Oakley, CA 94561 Pleasant Hill, CA 94523 032-250-703 020-150-002 032-280-009 Transamerica Mineral Co. Jeff Coyne Jonathon Scheitel 1150 Olive St., #2200 1528 20th Street P. 0. Box 151 Los Angeles, CA 90015 Santa Monica, CA 90404 Byron, CA 94514 032-330-021 032-340-010 032-280-011 Harvey & Rae Craig Haloti & Meliane Unga Transamerica Financial Service 6021 Golden Center Ct #315 P. 0. Box 998 - 50 Sand Creek Rd #200 Placerville, CA 95667 Oakley, CA 94561 Brentwood, CA 94513 032-100-020 032-082-011 032-182-009 Andrew & Carleen Daughters Pamela Scott Cohn Darrel & Marceline Edwards 2284 Dutch Slough Road 17256 N. Trethway Rd. 5395 Sandmound Boulevard Oakley, CA 94561 Lockford, CA 95237-9704 Oakley, CA 94561 032-191-033 032-191-045 032-100-013 c/o Wm. & Francene McCarty c/o Allan & Angela Berlund. -John Hotz, TRE. P. 0. Box 609 Rt. Z, Box 352 P. 0. Box 436 Bethel Island, CA 94511 i Oakley, CA 94561 Bethel Island, CA 94511 032-100-022 032-100-030 032-191-034 Lyle & Mildred Cohea Patricia Valenti c/o Almon Anglin P. O. Box 297 2432 Dutch Slough Rd. 101 Foster Oakley, CA 94561 Oakley, CA 94561 Vallejo, CA 94590 032-191-049 032-201-026 032-240-043 James & Cleo Williams c/o Priscilla Reed James Rickles 4303 Aberfoil Avenue Rt. 2, Box 351 931 American St. Oakland, CA 94605 Oakley, CA 94561 San Carlos, CA 94070 032-100-031 032-150-007, 6, 12 032-191-031 Jowonna Butler David & Delores Wollaston c/o Margaret Ferkert C/o Una B. Chaney P. O. Box 230 95 Monteta Way 279 Howe Court Bethel Island, CA 94511 San Francisco, CA 94112 Boise, ID 83707 032-191-043 032-192-013 032-201-029 c/o Reginald & Delphia Du Robert & Joan Spierer c/o James & Mildred Chadwick 563 Key Boulevard 5020 Page.Mill Drive 5070 Sandmound Boulevard Richmond, CA 94805 San Jose, CA 95111 Oakley, CA . 94561 032-240-044 Sherry Johnson Lorraine Henderson c/o Steven & Linda Masich 4626 Sandmound Boulevard 4935 Sandmound Boulevard 137 E. Hamilton Avenue Oakley, CA 94561 Oakley, CA 94561 Campbell, CA 95008 Mike Carter Linda Wadsworth Rhonda Hanson 5245 Sandmound Boulevard 4065 Woodhaven Lane 4800 Sandmound Boulevard Oakley, CA 94561 Oakley, CA 94.561 Oakley, CA 94561 Chuck & Ellen Shiles C:\wp51\shl\2918-rz.lab 3569 Wells Road April 15, 1993 Oakley, CA 94561 I STATEMENT OF FINDINGS AND OVERRIDING CONSIDERATIONS FOR THE CYPRESS LAKES & COUNTRY CLUB PROJECT i The East County Regional Planning Commission (the "Planning Commission") of - the County of Contra Costa, California (the "County") hereby : adopts and makes the following Findings (the "Findings") relating to its certification of the Environmental Impact Report (the "EIR") prepared for the Cypress Lakes & Country Club Project. I. INTRODUCTION I A. PROJECT LOCATIONIDESCRIPTION 1. Location. The project site is located in unincorporated north- eastern Contra Costa County, approximately 2 . 7 miles east of Oakley. The project site is located in the "off-island" portion of the Bethel Island Area, commonly known as Hotchkiss Tract. The project site is located at the junction of Cypress Road and Bethel Island Road and pis bordered by Bethel Island Road on the west, Sandmound Boulevard on the north and east, and agricultural uses on the south. ! 2 . Proiect Description. I The project site consists of seven (7) parcels, totalling 685.9 acres. The site is located in a flood plain. The current use of the project site is cattle grazing. The current zoning is General Agricultural District (A-2) and Heavy Agricultural District (A-3) . The project! will allow development of 1, 330 single-family homes and associated infrastructure. The project includes substantial recreational amenities such as an 18-hole golf course, beachand tennis club, a man-made lake and water channels, and public and private parks. The project also includes a fire station, a school site, a day care facility and a wetland mitigation area. ' The project site will be removed from the flood plain by an internal levee system. The projects residential aspect will consist of single-family lots and homes ; of varying sizes. The lots will range from approximately 5,000 square feet to 10, 000 square feet. The home prices will range from $175, 000 to $400, 000 per unit. i -1- 0UI T A__ ��� � e 3 . Discretionary Approvals. The project is presently requesting the following discre- tionary approvals by the County: rezoning from A-2 and A-3 to Planned Unit District (P-1) ; Preliminary and Final Development Plans; and Vesting Tentative Map. The project also requires approvals from the Local Agency Formation Commission (LAFCO) for annexations. The EIR has been prepared to cover all necessary approvals and/or permits which may be necessary to implement the project as discussed at pages 3-11 and 3-12 of the Draft EIR. The Planning Commission is the decision-making body on the Vesting Tentative Map and acts as the advisory body on the Rezoning and Preliminary and Final Development Plans. The Board of Supervisors is the decision-making body on the Rezoning and Preliminary and Final Development Plans. Thus, the approval of the Vesting Tentative Map is contingent on the Board's approval of the Rezoning and Preliminary and Final Development Plans. The Board will consider the EIR before making its decision on the Rezoning and Preliminary and Final Development Plans. The findings made by the Board with respect to the EIR will supersede these Findings. B. BRIEF ENVIRONMENTAL HISTORY OF THE PROJECT The project site has been the subject of several environmental documents. In 1989, the first environmental impact report was prepared. This EIR was prepared for the Bethel Island Area Specific Plan which covered the project site. This EIR was invalidated by the court in December, 1992 . A Draft EIR was prepared specifically for the project in August, 1992 . In response to the comments made on that Draft EIR, a revised Draft EIR was prepared in December, 1992 .. A Final EIR and Addendum were prepared in March, 1993 . These Findings are made on the December, 1992 Draft EIR, and March, 1993 Final EIR and Addendum. C. FINDINGS ON USE OF ADDENDUM An Addendum was prepared to include the letter from the Bay Area Air Quality Management District (BAAQMD) into the- Final EIR. The letter was not received by the County during the public comment period on the Draft EIR. The letter was read by a member of the public into the record at the Planning Commission meeting on February 8, 1993 during the public review comment period on the Draft EIR. A response to the letter was included in the Final EIR. The Planning Commission specifically finds, for the reasons set forth in the Addendum, that the Addendum was the appropriate document to address the addition of BAAQMD's letter. D. SCOPE OF THESE FINDINGS CEQA Guidelines at Section 15091 require that a project's significant environmental impacts identified in an EIR be addressed -2- by one of three findings, as set forth at 15091 (a) (c) . The EIR in this matter consists of the revised Draft EIR, dated December, 1992 , and the Final EIR and Addendum dated March, 1993 . To insure that all significant project impacts are identified, and necessary findings made, these Findings list the significant impacts and mitigation measures identified in the EIR and set forth the corresponding required finding. (Some beneficial impacts are also discussed in these Findings. ) Some of the mitigation measures have been modified. The modified mitigation measures are reflected in these Findings. E. DESCRIPTIONIOF THE RECORD For the purposes of CEQA and these Findings, the record before this Planning Commission relating to the project includes, without limitation, the following: 1. The County General Plan and its EIR; 2 . The original project Draft EIR dated August 1992; 3 . The revised project EIR; 4 . All findings prepared on the project, including those relating to the subdivision, and the recommended findings on the ; rezoning, and preliminary and final development plans; ! 5. All documents submitted as part of the project application including revisions to the application, and all studies, reports and materials accompanying or referenced in such application; and 6. All documentary and oral evidence received and reviewed, including at public hearings, relating to the project, and to' the adoption of the EIR, the County General Plan and its EIR and all related documents. F. GENERAL CONSIDERATIONS 1. Relianceon the Record. Each and all of the findings and determinations contained herein are based upon competent and substantial evidence, both oral and written, contained in the entire record relating to the project. The findings and determinations constitute the indepen- dent findings and determinations- of the Planning Commission in all respects. I -3- 2 . Nature of Findings. Any finding made by this Planning Commission shall be deemed made regardless of whether it appears in this document or is specifically labeled as a "Finding. " All of the language included in this document constitutes findings by this Planning Commission, whether or not any particular sentence or clause includes a statement to that effect. This Planning Commission intends that these findings be considered as an. integrated whole and, whether or not any part of these Findings fail to cross- reference or incorporate by reference any other part of these Findings, that any finding required or permitted to be made by this Planning Commission with respect to any particular subject matter of the project shall be deemed made as it appears in any portion of these Findings. 3 . Summaries of Impacts, Mitigation Measures, Facts, Alternatives and Other Matters. All summaries of information relating to the project are based on the referenced environmental documents and/or evidence in the record. The absence of any particular fact from any such summary is not an indication that a particular finding is not based in part on that fact. .: Moreover, the summaries set forth below, including, without limitation, summaries of impacts,, . mitigation measures and alternatives, are only summaries. Cross-references to the County General Plan, the County General Plan EIR and the project EIR and other documents in the record have been made and the reader should refer directly to those documents for more precise information regarding the facts on which the summary is based. 4 . Adoption of Mitigation Measures. These Findings are based upon the numerous mitigation measures set forth in the EIR or already included as part of the project plans. This Planning Commission is hereby adopting and incorporating into the project those mitigation measures set forth in the EIR which have not already been incorporated. into the project (with the exception of those mitigation measures that are rejected by the Planning Commission as more fully set forth below) . Some of the mitigation measures have been modified by this Planning Commission prior to their adoption. For easy reference, the modifications are identified in these Findings by the redline and strikeout. The redline (shaded areas) identify additions and the text stricken out identifies the text deleted from the measure. All of the mitigation measures now or previously incorporated into the project shall be implemented in connection with the project in accordance with the adopted Mitigation Monitoring Program. -4- r i i 5. Stpecific and General Mitigation. The EIR generally identifies, for each potentially significant impact of the project, one or more corresponding mitigation measures to lessen or avoid such impact. For ease of reference to the EIR, this document is organized in a similar manner. This Planning Commission recognizes that many of the mitigation measures described,below may lessen or avoid identified impacts other than those for which they-are specifically proposed. In light of the 'above, this Planning Commission finds that each mitigation measure adopted or already incorporated into the project may avoid or substantially lessen potentially significant impacts other than the ; impact to which such mitigation measure is corresponded in the EIR or below. I II. PROJECT IMPACTS AND MITIGATION A. LAND USE, PLANNING AND PUBLIC POLICY 1. Impact': The project would add 1, 330 dwelling units to the existing housing stock in price ranges between $175, 000 to $400, 000. This is a beneficial impact of the project. Mitigation: No mitigation is required. However,- the project plans include the following measures to assist in providing affordable housing and housing for the homeless: • 3 . 1-1 The project .will pay in lieu affordable housing fee equal to $3 , 333 per residential unit. This fee sneah37; be paid at the time of issuance of bu 1'ding permits for the project. As an alternative to the fees, the project applicant may construct a portion or all of the affordable housing units on-site. If this alternative mitigation is selected, the location and design of the affordable housing units should be submitted to the County for review and approval prior to the filing of a I final subdivision map. • 3 . 1-4 The project will pay an in-lieu contribution to the County Homeless Trust Fund.. The amount of the contribution will be determined by the County and paid, pro-rata, upon the issuance of building permits. i. Facts: The' County General Plan includes an "Off-Island Bonus Area" overlay designation on the project site which permits the development of 11. 0-2 . 9 single-family units/acre. (This density is identical to the Single-Family Residential-Low Density in the -5- I General Plan. ) The exact density is determined by the amount of recreational amenities provided by the project. The project will provide 2 . 21 dwelling units/acre.. The project is consistent with the General Plan policy that development projects should be at or near density maximums to provide as much housing as possible. The project plans include a contribution of in-lieu fees for affordable housing of $3 , 333 per dwelling unit constructed. Based on 1,330 units, $4 , 432 , 890 will be provided to the County to provide affordable housing where°needed. Mitigation Measure 3. 1-1 is modified to require payment- of the Fee at the time building permits are issued. The project applicant can provide affordable housing on-site, if approved by -the decision-makers. The project plans also include a contribution to the County's Homeless Trust Fund. The exact amount of this contribution will be determined by the Board of Supervisors at the time it makes a decision on the requests for rezoning and approval 'of the preliminary and final development plans. Findings: The Planning Commission finds that no mitigation is required since the project will create a beneficial impact on the existing housing stock. The Planning Commission finds that the project will create a beneficial impact on affordable housing and housing for the homeless. 2. Impact: The project will have a short-term unavoidable impact on East County's existing jobs/housing imbalance. Mitigation: The project plans include the following marketing scheme in an effort to reduce this impact: • 3 . 1-2 The project marketing s eidlel l3 be oriented ................. toward seniors` and retired people to reduce commute traffic from the project. Facts: The General Plan does not permit major job generating uses (i.e. , commercial/office/industrial) on the project site. The County, in its General Plan, designated this area for residential/ recreational development realizing that a job/housing, imbalance would occur. To reduce this impact, portions of the project will be marketed toward seniors and retired people. Measure 3 . 1-2 is modified to require marketing techniques. This marketing technique will not reduce the impact to a level of insignificance. The impact will remain unavoidable in the short-term until additional businesses and jobs are attracted to the East County area. Employment generating uses are expected to be included in the development plans for Cypress Corridor and Cowell Ranch, and in the new Brentwood General Plan. Mitigation by this project of this impact could only be accomplished if no new development was allowed which would be inconsistent with the General Plan. However, no development by this project would not eliminate or fully mitigate the imbalance since it already exists. -6- Findings: The Planning Commission finds that the project (which includes Mitigation Measure 3 . 1-2 as modified) will not mitigate the project's impact on the jobs/housing imbalance to a level of insignificant. 3 . Impact: The project will not have a direct impact on agricultural production. However, the conversion of the project site to urban uses will contribute to the incremental loss . of agricultural/open space lands. Mitigation: The General Plan requires the following of all projects in the Bethel Island Area to reduce the incremental loss on conversion ofiagricultural/open space lands. • 3 . 1-3 A Protection Fee shall be paid for each residential unit within the project to acquire development rights on agricultural land (and open space or wetlands areas) or to provide financing for farmers to continue agricultural production. Facts: Thelremoval of the project site from cattle grazing would not be considered a significant impact on the loss of agriculturally productive lands. The site contains agricultural lands classifieds by the County as "non-prime. " The soils are classified as "non-prime" because they have minimal fertility and only exhibit marginal agricultural productivity. According to the County General Plan, the site is not classified as important farmland. In recognizing the marginal agricultural value of the site, the County; included the site within its Urban Limit Line (ULL) and designated it for urban development. The County established a ULL, which is included in the General Plan, to provide for managed growth. The purpose of the ULL is to 1) ensure preservation of identified non-urban agricultural, open space and other areas by establishing a line which no urban uses can be designated; and 2) facilitate the enforcement of the 65/35 Land Preservation standard which requires that.65% of the County reflect non-urban uses. ; The ULL establishes those areas, such as the project site, within which urban development would be allowed. The project will add to the incremental loss of agricultural/ open space lands ;in the County. To reduce this impact, the General Plan requires projects in the Bethel Island Area to pay a Protection Fee as described above. This Fee shall be paid upon issuance of building permits. Findings: The Planning Commission finds that the removal of the project sitefrom agricultural uses will not have a significant impact on agricultural productivity. The Planning Commission further finds that the project's impact on the incremental loss of converting agricultural/open space lands to urban uses has been mitigated to a level of insignificance through Mitigation Measure -7- I " i 3. 1-3 , the establishment and implementation of the ULL, and the 65/35 Land Preservation Standard. 4. Impact: The proposed project layout would conflict with an existing private easement on the Dannelley property. Mitigation: The EIR sets forth the following measure to mitigate this impact to a level of insignificance: • 3 . 1-5 The project site plan shall be revised to clearly depict the existing easement from the Dannelley property to Cypress Road. This easement shall be maintained in its existing location unless otherwise agreed to by the property owner and the County. Facts: The above measure will be incorporated into the project. Findings: The Planning Commission adopts Mitigation Measure 3 . 1-5. The Planning Commission finds that this Measure will mitigate the above impact to a level of insignificance. B. TRANSPORTATION/CIRCULATION Note: The Mitigation Measures in this section are numbered consistent with those in the Draft EIR and are discussed "out of order" in these Findings. 1. Impact: The project would generate 10, 287 vehicle trips per day, including 730 trips during the AM peak hour and 1,036 trips during the PM peak hour. This will result in significant local traffic impacts, particularly along Cypress Road, Bethel Island Road, and Sandmound Boulevard. Mitigation: The EIR sets forth the following measures to mitigate to a level of insignificance local traffic impacts: • 3 . 2-1 Road Improvements at Project Entrance - Construct a new intersection at Cypress Road and Bethel Island Road, and on the approaches to this intersection. Widening ewes ' extend 1, 000 feet in each direction. _,,,.,,.To properly accommodate the project traffic as well as future traffic from other parts of the Bethel Island Area, the intersection will have the lane requirements shown on Figure 3 .2-13 of the Draft .EIR. The southbound approach will be widened with one more lane. This intersection shall be designed so that it can ultimately be consistent with a future extension to Byron Highway south of the -8- ! intersection. -Cypress Road will cross the levee just east of the entrance to the project. The vertical curvature of Cypress Lakes Road where it crosses the levee shall be submitted prior to final map approval— r1:d"' eotl1a 45 mph design speed;; .wau3:e1 be e e6li6b e -This project wt include the installation of traffic signals thatwv��el be put into operation at the time that volumes meet Caltrans traffic warrants. This is estimated > at'en 500 units completed and occupied. • 3 .2-2 Bethel Island Road and Sandmound Boulevard - i a i The intersection sturrs3C? be improved and widened, and left turn lanes- Y a:13 be constructed. Sandmound Boulevard heti IE� W."T be realigned to a right-angle intersection ..at Bethel Island Road. This project waw-w also include the installation of traffic signals that wets-lda 1'; be put into operation at the time that volumes meet Caltrans traffic warrants. • 3 . 2-3 j Cypress Road Widening - Complete the imple- mentation of the Cypress Road widening from Machado Lane to east of Knightsen Road. This roadway improvement sheul-dhas-1-i'.1 be in place before 1, 000 units are occupied at Cypress Lakes. It wo� .� z11 include the installation ............... of traffic signals at Sellers Road and Knightsen Road that would be put into operation at the time that volumes meet Caltrans traffic i warrants. • 3 . 2-4 Sandmound Boulevard Improvements - Reconstruct Sandmound Boulevard from Bethel Island Road along the north border of the project and along the project's easterly frontage on Sandmound Boulevard. Facts: Mitigation Measures 3 . 2-1 through 3 . 2-3 are modified to be mandatory !rather than optional. In addition to the above Measures, consistent with the conditions of approval, the applicant shall construct safety improvements at the intersection of Cypress Road and Jersey Island Road. The conditions of approval contain extensive on-site and off-site roadway improvements and are incorporated herein by this reference. These traffic improvements will be incorporated into the project plans and installed as required. i -g- i i i Findings: The Planning Commission adopts Mitigation Measures 3 . 2-1 through 3 .2-3 as modified, and 3 .2-4 . The Planning Commission finds that these Measures in addition to the project plans, conditions of approval, and other adopted traffic Mitigation Measures, will mitigate local traffic impacts to a level of insignificance. 2 . Impact: Currently, there are no roadways on the project site. The project will create the need for new roadways. Mitigation: The EIR sets forth the following changes to improve circulation on-site and conform with future development in the Bethel Island Area: • .3 .2-8 Design level plans for the project entrance on ................... Sandmound Boulevard � al be prepared ................... -- and submitted to County Public Works Department for review and approval prior to approval of the first phased subdivision map. The design ................... level plans-sh::a>l provide for: adequate .................. ................... transition from the levee cross-section to grade at Sandmound Boulevard; adequate stopping distance; and adequate corner sight distance. • 3 .2-9 Provide a right-of-way for a future roadway connection to the property south of Cypress Lakes, and construct the road up to the edge of the levee. This property could develop into a residential neighborhood, and sheldld be connected into Cypress Lakes %at stere— e- in h �e=ti > c'erel cs"''s, ::.::::::::.::::::....:...,..........:........:....: .:...:..:.. .:. especially for school trips and other internal recreational trips. However, such a roadway connection -s; 'a';3:]; not be the only access ................... ................... ......... ....moi i a :.. to this new area, and 4heuld be provided only after Bethel Island Road isextended south across Rock Slough. This road should be . ............... ................... treated as a secondary connection, so that it will limit the amount of through traffic that would travel through the Cypress Lakes development. • 3 . 2-10 Provide a road extension of Cypress Road through the project to connect Sandmound Boulevard. This connection -y ;5; allow ............... ............... for more convenient access for existing residents, providing a connection to the future school site, and easy access to Cypress Road through the project. -10- I i ! f i Facts: The internal improvements proposed by the project are identified in Figure 1-3 at page 1-5 of the Draft EIR and discussed throughout the Traffic Section of the EIR. Mitigation Measure 3.2-8 is modified' to ensure that the design plans will contain the specified criteria and be submitted to the County for review. Mitigation Measure 3 .2-9 is modified to ensure that a new roadway will be providedi but will not be the only access . to the future development south of the project. Mitigation Measure 3 .2-10 is modified to ensure the extension is provided. The above Measures will be incorporated into the project design. Findings: The Planning Commission adopts Mitigation Measures 3 . 2-8 through 3 .2-10 as modified. The Planning Commission finds that these Measures in addition to the project plans, conditions of approval and other adopted traffic Mitigation Measures, will ensure that an adequate internal circulation network is provided. i 3 . Impact: The project will increase pedestrian and bicycle traffic. I Mitigation: ! The EIR sets forth the following measures to ensure that adequate pedestrian and bicycle paths are provided: • 3 . 2-111, Provide a major bicycle path within the project on Cypress Road between Bethel Island Road and Sandmound Boulevard, and on Cypress Lakes Drive through the project. This pathway s`'euld=:Sl <1 be designed to County standards. • 3 . 2-12 ] At such time as other roadway improvements are completed, complete other bicycle paths as ! required. This =v1 include a pathway { along Bethel Island Roac�""'O"'n the west boundary of the project, a pathway along Rock Slough on the southern boundary of the project, a path along the Byron Highway Extension, and a pathway along Sandmound Boulevard on the north i and east boundaries of the project. Facts: There are few. bicycle paths in the Bethel Island Area. With the increase in population in the area, such pathways will be necessary. Pedestrian and bicycle trails are proposed throughout the project as shown on Figure 3 .9-3 at page 3-184 of the Draft EIR. In addition to the trails recommended by Measure 3 .2-11, trails are proposed on top of the internal levee and adjacent to the open space corridor that crosses the project site. The above Measures will ensure that adequate on-street paths are provided. Mitigation Measure 3 . 2-11 is modified to ensure that the trails are designed to meet; County standards. Mitigation Measure 3 . 2-12 is modified to ensure that additional trails will be provided as future development occurs in the area. ' -11- i Findings: The Planning Commission adopts Mitigation Measure 3.2-11 and 3 . 2-12 as modified. The Planning Commission finds that these Measures in addition to the project plans and conditions -of approval, will ensure that adequate pedestrian and bicycle trails are provided throughout the area. 4. Impact: Traffic generated by the project will contribute to cumulative traffic. Mitigation: The EIR sets forth the following measures to mitigate cumulative traffic impacts to a level of insignificance: • 3 .2-5 Conformance with Measure C - The Cypress Lakes '.project would satisfy the requirements of Measure C by constructing the roadway improve- ments listed in Table 3 .2-6 (A) at page 3-53 of the Draft EIR. The prejeet may alse be measure "e" prejeets. This fee has net been established and is eurrently being evalua these fees will help te mitigate the regienal • 3 .2-6 Bus Transit Service While there is no current transit in the area, it can be expected that daily bus transit service, provided by Tri-Delta Transit, weidid- 'h7I be provided to .... ............. .................. the Hotchkiss Tract and BetheI...Island Area when a .significant amount of the development in the area has been built and occupied. The ................... situation s euld §h-A:11 be monitored, and ................. ................... transit service s be started when about 1, 000 homes have been completed in the area. This bus route eould Ill be an extension. of Routes 383 and/or 384 arid. = r ; follow Cypress Road and Bethel Island Road to a terminal stop on Bethel Island. • 3 .2-7 Participate in County TDM Program - The project weuld—shall be required to comply with the County res"ii3ential TDM Ordinance, the County Growth Management Program; and the Bay Area Air Quality District regulations regarding trans- portation. TDM requirements of the County include the preparation and distribution of a TDM information program that i' 1 ................... include the provision of maps showing avai�Yable transit routes, and information on ridesharing and vanpool services to prospective home buyers. These types of measures can be -12- i expected to have only a relatively small impact on reducing peak`- hour trips. Other studies have shown that TDM actions applied to a residential development can reduce the number of single occupant auto trips by 3% to 5% during the commute peak hours. • 3.2-16Subregional Road Fee - Payment of the subregional road fee for improvements on SR 4 in the freeway section between Bailey Road and Highway 160 and on the arterial section between Highway 160 and Cypress Road. The following Mitigation Measures must be addressed by the project if the Delta Expressway is not implemented, and if the impact is not mitigated by other sources: • 3 . 2-14i Intersection of Neroly Road and SR 4 (Main Street) - Widen the northbound approach to provide a double left turn from Neroly to SR 4 . This will improve the V/C ratio from 0. 93 ("E") to 0. 81 ("D") . This will reduce this impact to a less than significant level. The project traffic will amount to about 10% of the traf f is growth that is projected at this intersection. The project applicant shauld ha] pay a fair- share contribution equal to 10% of the cost of the improvement. I • 3 . 2-15 ' Intersection ofCypress Road and SR 4 - Widen ;. the southbound approach to provide a double left turn lane for traffic from SR 4 to Cypress Road, and widen Cypress Road on the east leg of the intersection. This will improve the V/C ratio from 0. 87 ("E") to 0.79 ("C") , and will reduce this impact to a less than significant level. The need for this improvement will depend entirely on the pace of development and the timing of the construction of the Delta Expressway. If the Cypress Corridor develop- ment moves quickly to implementation, prior to the completion of .the Delta Expressway, this mitigation will be required. The need for this improvement will be reduced if the Laurel extension is completed, and the Laurel Avenue connection to. . the Delta Expressway is j completed. Traffic from the Cypress Lakes project wi 11.amount to about 25% of the traffic growth that is .projected at this location. The applicant shed--shall; be required to pay a fair share fee equal to about 25% of the cost of this improvement. -13- i I Facts: A regional traffic fee for Measure "C" projects, as identified in Measure 3.2-5, will not be established by the time the project is approved. Mitigation Measure 3 .2-5 is modified to reflect this fact. However, the project will comply with the Measure by constructing the roadway improvements in Table 3 .2-6 (A) at page 3-53 of the Draft EIR. In addition, there is no longer a subregional roadway fee as identified in Mitigation Measure 3.2- 16. In recognition thereof, the applicant will construct the roadway improvements listed in the Draft EIR at page 3-53 and contribute to the following regional improvements: • State Highway 4 - Cypress Road intersection ($25/unit) ; • State Highway 4 - Neroly Road intersection ($30, 000) ; • Cypress Road between State Highway 4 and Machado Lane ($50/unit) ; • Delta Expressway ($1, 000/unit) ; and • Extension of Byron Highway from .Delta Road to the intersection of Cypress Road and Bethel Island Road ($726/unit) . The conditions of approval more fully explain the applicant's contribution to the above regional roadway improvements , and are incorporated herein by this reference. The conditions of approval also outline other roadway improvements that are the responsibility of the applicant. The applicant will also be required to pay the County-wide Area of Benefit, Bethel Island subarea fee of $3347/unit for other improvements in the area including but not limited to the Cypress Road - Laurel Road connection from State Highway 4 to Machado Lane and for widening of Laurel Road from State Highway 4 to. .the proposed State Route 4 Bypass. The project will provide bus turnouts on Cypress Road at the intersection of Cypress Lakes Drive and along Cypress Lakes Drive, Sandmound Boulevard, Bethel Island Road, Cypress Road and Country Club Drive. The applicant shall also deposit funds, as determined by Tri-Delta Transit, for bus stop shelters, and bicycle racks and lockers. Mitigation Measures 3 .2-6, 3.2-7 , 3 . 2-14 and 3 .2-15 are modified to ensure compliance. The implementation of all the traffic Mitigation Measures, compliance with the conditions of approval, and the applicants contribution to the above regional improvements will mitigate the project's cumulative impacts on traffic to a level of insignificance. -14- I I I Findings: The Planning Commission rejects Mitigation Measure 3 .2-16 for the reason stated above and adopts Mitigation Measures 3.2-5 through 3 . 2-7, 3 . 2-14 and 3 .2-15 as modified. The Planning Commission finds! that the adopted Measures in addition to the applicant's contribution to the regional improvements mentioned above, the conditions of approval and other traffic Measures adopted in the Findings, will mitigate the project's cumulative impacts to a level of insignificance. 5. Impact: Construction of the project would result in additional construction truck traffic on Cypress Road and State Route 4 . i Mitigation: ; The EIR sets forth the following measure to mitigate the impact to a level of insignificance. • 3 . 2-13 ; Contra Costa County has standard restrictions on construction activities regarding hours of operation, noise and dust control. Additional mitigation eedl:d shah include restrictions on heavy trucks from SR 4 during the commute peak hours. The project eeuld nermally shan l'1 be I required to assist in maintenance of roads that axe damaged by heavy trucks. Since the major access route, Cypress Road, . weuld shall: be partially reconstructed by the project, this Gerrie. project condition may not be necessary. Facts: Mitigation Measure 3 .2-13 is modified to be mandatory rather than optional. The above Measure will be incorporated into the project. Findings: The Planning Commission adopts Mitigation Measure 3 .2-13 as modified. The Planning Commission finds that this Measure will mitigate to a level of insignificance construction truck traffic impacts. C. AIR UALITYI 1. Impact: Project construction will create air quality impacts due to dust generated by equipment and vehicles. I Mitigation: , To ensure dust emissions are kept at a minimum during construction, . the following measures are set forth in the EIR: • 3 . 3-1 The dust control measures proposed as part of the project plans sheuld sha11. be made conditions of project approval. I -15- I • 3 . 3-2 In addition to the dust control measure proposed by the project, all construction vehicles sheulh be limited to 15 mph d while on the project site. The 15 mph limit be posted on the site at all times during construction. • 3 . 3-3 In addition to the dust control measures included in the project plans, the name and phone number (business and non-business hours) for the dust control coordinator shall be posted along the perimeter of each construction site. This information shall also be provided by mail to residents within 1, 000 feet of the construction area. 0 3 . 3-4 Earth moving and other dust-producing activities shauldbe suspended when A. . ... ................. . .............. watering and other dust control measures are unable to eliminate visible dust plumes. Facts: Mitigation Measures 3 . 3-1, 3 . 3-2 and 3 . 3-4 are modified to be mandatory and not optional. To reduce dust emissions during construction, the project plans include the dust control measures discussed at pages 3-69 and 3-70 of the Draft EIR. Significant dust emissions are generated by earth moving equipment. Major earth work (excavation of lakes and levee construction) is estimated to take approximately one year. As required by Mitigation Measure 3 . 3-4 , earth moving activities (in addition to others) will be suspended if dust emissions cannot be adequately controlled. Dust emissions from earth moving equipment (and other construction activity) will be mitigated . .to a level of insignificance through the implementation of the dust control measures and the above measures. Findings: The Planning Commission adopts Mitigation Measures 3 . 3-1, 3 . 3-2 and 3 . 3-4 as modified and Measure 3 . 3-3 . The Planning Commission finds that the project plans (which includes the dust control measures) in addition to the above adopted Measures will mitigate this impact to an insignificant level. 2 . Impact: The daily increase in Reactive .Organic Gases (ROG) and Oxides of Nitrogen (NOx) , two precursors of ozone, asso- ciated with the project will exceed the criterion of 150 lbs/day. Therefore, the project will have a significant effect on these two regional emissions/pollutants. Mitigation: The EIR sets forth the following measures to address project related regional emissions by reducing traffic volumes generated by the project: -16- • 3 . 3-5 Comply with the County's Transportation Demand Management Program Ordinance 92-31 by preparing and providing TDM information to prospective a home buyers. The TDM information auld contain materials describing transit, r did sharing and van pool services. • 3 . 3-6 The projects-- a' provide for transit stops along Cypress "Road within the project site, along Cypress Lakes Drive, . Sandmound Boulevard and Country Club Drive. • 3. 3-7 The proposed project design includes pedestrian/bicycle paths linking recreational and residential uses within the site. In addition to these facilities, bicycle parking areasbe provided at all recrea- tional facili� es''within the project site (golf course clubhouse, beach club and public park) . Facts: Mitigation Measures 3 . 3-5 through 3 . 3-7 are modified to require compliance. The above Measures will result in a maximum trip reduction of 10; with air quality impacts associated with auto use being reduced proportionally. Even with reductions of this magnitude, the incremental impact of the project on regional air quality with respect to ROG and NOX will remain significant. There is only a limited;potential for effective mitigation of this impact since the majority of the project's impact on air quality results from cumulative ;impacts and transportation sources beyond the control of the applicant and local regulatory agencies. The most effective mitigation is the implementation of the above measures. Findings: The Planning Commission adopts Mitigation Measures 3.3-5 through 3 . 3-7 as modified. The Planning Commission finds that these Measures will not reduce regional air quality impacts (with respect to ROG and NOX) to an insignificant level. Thus, the project's impacts on ROG and NOX are significant and unavoidable. D. VEGETATION AND WILDLIFE 1. Impact: The project will result in the removal of approximately 0:75 acres of the 6. 52 acres of wetlands and .20 acres of the 2 .66 acres of the waters of the U.S. on the project site. Mitigation: ; The project plans include the following measures to reduce the impacts on vegetation and wildlife: ! -17- • 3 .4-1 Implementation of the Wetland Habitat Mitigation Monitoring Plan which is designed to replace impacted wetlands by enlarging and enhancing the existing wetlands on-site. The goal ef the mitigatien pPlan create ... .......... .... ............... an additional 2 .28 acres.. of seasonal. wetlands wetlands by enlarging and enhancing the existing wetlands on-site. Buffer areas around wetland areas gid- d' : also be provided .................. • 3 . 4-2 Implementati-6h` o"''f" the Channel Enhancement Plan which weuld---�6h'All enhance and widen the ................... ................... existing primary drainage ditch to a channel of approximately 8 acres in size. A new north/south channel weuld 6ha"I-1 also be created to connect to the lake. The channels ifeuld sa A-1-:11 be sprigged with willows and cottonwood ................... ................... cuttings to provide riparian habitat. Mitigation: The EIR sets forth the following additional measures to mitigate the project's impact on vegetation and wildlife to an insignificant level: • 3 . 4-3 The project includes widening of the primary drainage channel ("main drain") and the creation of additional channels on the project site to improve wildlife habitat and the visual quality of the project. The project applicant should—... ....� prepare a detailed Channel ........ . Enhancement Plan based on the draft Channel Enhancement Plan provided by the applicant. The Plan e-Aieu44--, h:4il be submitted to Contra . ................... ................... Costa County, Arid the California Department of Fish and Game �nd the U. S. Army Gerps ef Engineers for review and approval prior to approval of the project 's final subdivision maps. • 3 . 4-4 To minimize impacts to wildlife movement along the drainage channel, road crossings Shed .... .... ... h` ': A.1.1 utilize clear span bridges 44 feasible. ................. ............................. t ............ "t e, Culverts a e ................... be use&; d' they sheuld be as large ............ ..............gn ..P: . .......... .............. as poss ible to minimize impacts to wildlife movement.. The design of all bridges and/or culverts to be placed along the primary drainage channel ("main drain") . shall be submitted for review and approval to Contra Costa County Department of Public Works, Reclamation District 799 :9 . ....... . ......... California Department of Fish and Game. air d"0;8. Army Gerps ef Engineers prior to filing a final subdivision map. 18- • 3 .4-5 i The project plans include a draft Habitat Mitigation and Monitoring Plan whichl replace wetlands on-site, in a ratio of 3 acres for every 1 acre impacted (0.75 acres impacted to be replaced with 2. 28 acres of new wetland) by enlarging and enhancing the existing wetlands on the project site and providing buffer areas around wetlands. The Habitat Mitigation and Monitoring Plan sheuld be reviewed and approved by the County, California Department of Fish and Game e-f- Engineers prior to filing a. final subdivision map. • 3 .4-6 Wetlands and waterways impacted by the proposed project are considered waters of the United States and therefore come under the Jurisdiction of Section 404 of the Clean Water Act. Filling in waters of the United States requires a permit from the Department ef the A U.S. Army Corps of Engineers. The project applicant is required to obtain a permit from the U. S. Army Corps of Engineers before filling of any wetlands or waters on the project site only if filling more than one acre. permit,defined by the U. S. Army Gerps ef Army Gerps ef Engineers The California Department of Fish and Game may needtz ' be notified regarding project activities iii the 1. vicinity of the main drain pursuant to Fish and Game Code Section 1600, et seq. • 3 .4-7 The project she pay ay the County Protection Fee, as required by the County General Plan, for acquiring development rights on wetland areas off-site. The Protection Fee I should hal be paid upon the issuance of .............. building permits for the project. Facts: The project was designed to avoid and where not biologically significant, minimize impacts on wetlands and other wildlife. The project avoids the most significant wetland areas and will replace- the insignificant areas that were not avoided, by a 3: 1 ratio. Mitigation Measure 3 .4-1 is modified to ensure proper mitigation of the wetlands. Mitigation Measure 3 . 4-5 is modified to require review and approval of the final Habitat Mitigation and Monitoring Plan by the County and Department of Fish and Game. -19- In addition, the project shall enhance the existing drainage ditch to a channel and construct an additional channel. The project plans includes a draft. Channel Enhancement Plan which includes the sprigging of the channel banks with willow and cottonwood cuttings. This enhancement shall provide greater area for wildlife species (such as the great horned owl and pond turtles) than presently exists on the site. Mitigation Measure 3.4-2 is modified to clearly reflect the criteria in the Plan. Measure 3 .4-3 is modified to require the preparation of a final Plan and require review and approval of the Plan when finalized. The project will only fill 0.75 acres of wetlands and 0.20 acres of waters of the United States. The Army Corps of Engineers does not regulate "fills" of less than one acre. As a result, the Corps will not review or approve the Channel Enhancement Plan, the - Wetland Habitat and Mitigation Plan, or the channel crossings. Mitigation Measures 3 . 4-3 through 3.4-5 are modified to eliminate reference to the Corps. With respect to Mitigation Measure 3 . 4-4, Reclamation District 799 will only review and approve the channel crossings if it accepts the drainage on site. A request for acceptance has been submitted by the applicant and is currently being considered by RD-799. A permit under Section 404 of the Clean Water Act is only required by the Corps if the applicant fills more than 1 acre of regulated waters. As discussed above, the filling of 0.75 acres of wetlands and the 0. 20 acres of the channel are not regulated activities. The Corps will be notified before construction in these areas begin but it willnot issue a permit. Mitigation Measure 3 .4-6 is modified to reflect this change and ensure that the Department of Fish and Game will review the activity. Mitigation Measure 3 . 4-7 is modified to require payment of the Protection Fee at the time building permits are issued. Findings: The Planning Commission directs that the project plans incorporate the modifications to Mitigation Measures 3 .4-1 and 3 .4-2 . The Planning Commission adopts Mitigation Measures 3 .4-3 through 3 .4-7 as modified above. The Planning . Commission finds that the project plans in addition to the adopted Measures will reduce the project's impact on vegetation and wildlife to a level of insignificance. E. VISUAL QUALITY 1. Impact: The project will change the existing visual character of the site from agricultural uses to one of a suburban residential community with various recreational uses. Views of the project site will be partially blocked by a levee which will surround the project. -20- i i Mitigation: The following measures are included in the project plans to ;address visual impacts: • 3 . 5-1 Landscape criteria for the proposed golf course, parks, common areas, project levees and the channels. Landscaping weu444h&11 consist primarily of low grasses and wilc]f'Yowers with some introduced shrubs and trees. • 3 . 5-2 Landscape guidelines for the proposed levee system. These guidelines are designed to be consistent with the landscape guidelines of the State Reclamation Board. A list of suitable plant species is provided as part of the guidelines. • 3 . 5-3 A landscape strip ; ettlel be provided outside the project levee to provide screening of the levee along Bethel Island Road and Sandmound Boulevard. The landscape strip would s`h' 1 be a minimum of 10 feet wide and be located sufficiently outside the levee cross- section to not hinder maintenance of the levee. The landscape strip sheulel 1 be planted with trees and shrubs to provide maximum screening. Maintenance of the landscape strip weuld 5 11' be carried out by the homeowners' association or special district but not the public agency responsible for maintenance of the project levee. • 3 . 5-4 Residential units wilsh........... be limited to two ........ stories not to exceed 30 feet. • 3 . 5-5 Minimum setbacks along arterial roadways will stall: be 200 feet, and 100 feet from the center Pirie of the roadway to the exterior wall of any living space along collectors (Cypress Road Extension) . • 3 . 5-6 Sideyard setbacks will-sa vary taking into ;:.�..^.::�:is a ; account: 1) structures s�=. h3>1 not block solar access for heating and cooing; 2) space between buildings shall increase in relation to their height; and 3) periodic view corridors to water areas h-a�s '11 be provided. ............. ... ................... The EIR sets forth the following additional measures to further address visual quality impacts: -21- i • 3 . 5-7 The levee landscape guidelines sheul4t A3! be finalized once the public agency to be responsible for maintaining the levees is determined. The levee landscape guidelines .. sheuld ... .1, then be submitted to the public ... . ........ .................. .-- agency responsible for maintenance of the levees for review and approval prior to the installation of any landscaping on the levees. • 3 . 5-8 A landscape maintenance district, or other funding source consisting of the property owners within the project site, shall be established for the proposed project to pay for long-term maintenance of public recreation areas within the project site. The project applicant shall submit a proposal for the landscape maintenance district to the County for 'approval prior to approval of the project-'s final subdivision map. Facts: Mitigation Measures 3 . 5-1, 3 . 5-3 through 3 . 5-7 are modified to require compliance. The visual character of the site will change from generally vacant, flat pasture land to residential/recreational uses. The project includes a levee. The individuals most impacted by this visual change are those living along Sandmound Boulevard and the 3 residences within the project site. All exterior levee slopes will be 3 to 1, except in the area along Sandmound Boulevard where the slope will be 4 to 1. The 4 to 1 slope is a more gradual slope which will reduce visual impacts along Sandmound Boulevard. The project plans include a landscape plan for the slopes of the levee. If landscaping on the levee is not permitted, the landscape plan for the project perimeter will be implemented. Either way, landscaping will be installed to shield the levee from Sandmound Boulevard and other areas outside the project. The project design includes considerable amounts of landscaped areas and permanent open space areas such as the golf course (170.3 acres) , a lake and water channels (61 acres) , parks (33 .7 acres) and existing wetlands and wetland mitigation/buffer areas (17 . 5 acres) . The project features will improve the visual character of the site. However, the project will also significantly change the existing visual character of the site. This is considered a significant unavoidable impact of the project. Findings: The Planning commission adopts Mitigation Measures 3.5-1 as modified, 3 . 5-2 , 3 . 5-3 through 3 . 5-7 as modified, and 3. 5-8 . The Planning Commission finds that the project plans (which includes Mitigation Measures 3 . 5-1 through 3 . 5-5) in addition to the adopted Measures, will not reduce all visual impacts to a less than a significant level. -22- F. NOISE i 1. Impact:' Existing houses along Cypress Road just west of the project entrance will be exposed to a significant noise impact due to increased traffic by the year 2000. Mitigation: ; The EIR sets forth the following measure to mitigate potential noise impacts along Cypress Road: 3 . 6 : Neise----mitig-a-tien installed installe , Lrryite1tTLaZ—trQatmL^is) i - -- -g' elpr--- Read I f-er the prejeet entrance to Sellers Read ,..i.,..,,la residentfer uses. The prejeet a'i'ivtirsu—Ac 0 i laased on the ealeulation that the level aleng eypress Read whieh is 10 dB ever the Geunty's 69 dB geal. The remaining o ef 41 the—e e o future develepnent 0 ) . The prejeet's paid at the time ef filing eaeh phased final Ynap— Facts: Existing residences along Cypress Road are currently exposed to a "conditionally acceptable" noise level of 64 dB. The project will add an additional 4 dB by the year 2000. The 4 dB increase will not be considered in and of itself a significant impact since the area is already, exposed to "conditionally acceptable" levels. The 4 d increase would keep the noise level at "conditionally acceptable. " Other planned development will add 2 dB by the year. 2000. The community has continually voiced its objections to soundwalls (i.e: , Final EIR p. 4-85) . The installation of architectural treatments will require the owner's consent and cooperation. There are approximately forty residences along this road. As a result, these measures are not feasible. The County's planned improvements along Cypress Road will adequately mitigate the noise impacts without the above measure. The planned improvements include a. 30 foot buffer between the roadway and the 'existing residents. This buffer includes 20 feet of landscaping and berming and 10 feet for a drainage ditch. These improvements will be funded and/or constructed as development proceeds in the Bethel Island Area. (This project will construct improvements along Cypress Road as discussed in the Traffic Section of these Findings and identified in the project's conditions of approval. ) The; Cypress Road improvements are planned to occur i i -23- I before the year 2000 and before the noise levels along this roadway exceed "conditionally acceptable" levels. Moreover, the revised application for Lesher Landing identifies a "new" Cypress Road inside its proposed internal levee and the existing Cypress Road as a frontage road. This design, if approved, will reduce noise impacts along Cypress Road to a level of insignificance and would alleviate .the need for any additional mitigation. Findings: The Planning Commission rejects Mitigation Measure 3 . 6-1 as infeasible for the reasons stated above. The Planning Commission s finds. that the planned improvements or the Lesher Landing project, in lieu of soundwalls. and architectural treat- ments, will reduce -the noise impact along Cypress Road to an insignificant level. 2 . Impact: Existing residences adjacent to the site, particularly along Sandmound Boulevard, and the residences within the project, will be exposed to a short-term significant impact from construction noise. Mitigation: The EIR sets forth the following measures to reduce construction noise impacts: • 3 . 6-2a. All general construction activity= 1 be limited to the hours of 7 : 30 a.m. to 7: 00 503 -P.m. on weekdays only. b. Operations of any machine or device which generates a noise level greater than 95 db at 50 feet she id—sha7.. be prohibited wherever .................. .................. .................. feasible. C. Route heavy construction traffic along existing Cypress Road and the proposed Cypress Road to minimize the impact on existing residences. ................... No construction traffic s etild- h`aI3 be routed ................. ................... along Bethel Island Road or....... Sandmound Boulevard. d. Prohibit construction trucks from parking along existing Cypress Road west of the project entrance. e. Locate noisy stationary equipment, such as compressors or. pumping stations .. away from existing residences to reduce their noise impact. -24- Facts: Section (a) of the above Measure is modified to require construction activity to cease'at 5:00 p.m. as opposed to 7:00 p.m. Sections (a) through (c) are modified to require compliance. The above Measure will reduce construction noise to the extent possible. There may be times when construction noise levels may be : considered significant in comparison to the relatively low existing noise levels in the area. The residents along Sandmound Boulevard (closest to the project site) and those within the proje:'ct will be most affected by the change in noise levels. Findings: The Planning Commission adopts Mitigation Measure 3 . 6-2 as modified. The Planning Commission finds that the above Measure will not mitigate, at all times, noise levels resulting from construction activities to an insignificant level. This impact is considered a short-term unavoidable impact. 1 3 . Impact.* The homes along the extension of Cypress Road within the project will be exposed to an existing and future DNL of 65 dB. This!s is 5 dB over the County goal for normally acceptable outdoor noise levels but is within conditionally acceptable noise levels. Mitigation: ! The project plans include the following measure I to reduce noise impacts along the Cypress Road extension: • 3 . 6-3 In order to avoid adverse noise levels at homes located along the extension of Cypress Road through the project, the project has been designed to provide a 100-foot set-back along Cypress Road. The 100-foot set-back weulel be from the center line of the roadway to the nearest exterior wall of each residence located along Cypress Road. The 100-foot set- back reduce the noise level at these residences to a DNL of 60 db which is consistent with the County's noise goals for residential uses. Facts: Mitigation Measure 3 . 6-3 is modified to ensure that the setback is provided. The 100 foot setback along the Cypress Road extension will reduce the noise level to a DNL of 60 db which is acceptable and consistent with the noise goals in the General Plan for residential uses. Findings: :The Planning Commission directs that the project plans include the modification to Mitigation Measure 3 .6-3 . The Planning Commissions find that this Measure will reduce noise impacts along I' the Cypress Road extension to a level of insignificance. -25- G. HYDROLOGY AND DRAINAGE 1. Impact: The project will increase the area of imperme- able surfaces and increase storm water runoff. Mitigation: The following measures are contained in the project plans to mitigate drainage impacts to a level of insignificance: • 3 .7-1 On-site storm drainage facilities (lake, water channels and golf course detention facilities) shall be constructed to both protect property and to provide for public safety by accommodating the 100-year storm event. • 3 . 7-2 Dewatering structures (discussed in the Water Quality at pages 3-139 through 3-143 of the Draft EIR) shall be constructed at those points where underground storm drainage pipes enter the channel/lake system in order to facilitate the periodic flushing and cleaning of the underground pipes. • 3 . 7-3 Drainage ditches shall be constructed along the exterior toe of the proposed levee system to catch that runoff from the exterior slope of the levees. The drainage ditches shall discharge into existing drainage ditches along the perimeter of the project. • 3 . 7-4 Maintenance of on-site storm drainage improve- ments within the public right-of-way, or in suitable easements, shall be performed by the County of Contra Costa. Storm water pump station maintenance shall be performed by the public entity selected to be responsible for the operation and maintenance of the perimeter levee. Facts: The proposed channel/lake system and storm drainage network system will reduce the project's drainage impacts to a level of insignificance. Storm drainage will be collected on-site and terminate in the proposed channel/lake system. During storm periods when excess water accumulates on the site, waters from the lake will be pumped to ultimate disposal in Sand Mound Slough by a pump station that will be constructed as part of the project. Water pumped into the slough will be treated and will meet all requirements of the County's NPDES permit requirements (see Mitigation Measure 3 . 7-17 . ) -26- Findings: The Planning commission finds that the project plans (which include Measures 3 .7-1 through 3 .7-4) will reduce drainage impacts to a level of insignificance. 2. Impact:' The 685 .9 acre project site will be removed from the flood plain by an internal levee. Residents in the area are concerned that this levee will jeopardize their safety by removing area in which water can travel in the event of a breach on the existing levee. Mitigation: The EIR sets forth the following mitigation measures to ensure proper construction, landscaping and maintenance of the internal levee system: • 3 .7-5 The design of the project levee shall be in accordance with the standards and requirements of the Federal Emergency Management Agency for an Urban Standard Levee. Provisions shall be designed into the project levee to allow for a future increase in height of 4 feet to allow for the "greenhouse effect. " During the design of the project levee, the crest elevation shall be increased by an amount equivalent to projected long-term settlement. • 3 . 7-6 The side slopes of the project levee shall be planted and irrigated to reduce erosion, and to provide dust control, in accordance with the limitations imposed by FEMA. • 3 .7-7 Adequate easements shall be granted to the maintaining authority in order to provide for maintenance and upgrading of the levee, and to prohibit encroachments onto the levee. • 3 . 7-8 iTo minimize the risk of liquefaction beneath the perimeter levees, the loose clean and silty sand of depths of 10 to 15 feet shall. be reworked and densified. Deep eb Over excavation and compaction of soils shall be utilized to densify the soils. • 3 .7-9 The levee landscape guidelines �.... be finalized once the public agency responsible for maintaining the levees is determined. The levee landscape guidelines eheu_ ° then be submitted to the public agency responsible for maintenance of the levees for review and approval prior to installation of any landscaping on the levees (same as Mitigation Measure 3 . 5-7 . ) -27- • 3 . 7-10 A final emergency evacuation plan based on the project's proposed emergency evacuation plan shall be prepared in - cooperation with RD-799 and the governmental agency that ultimately accepts the internal levee system prior to approval of the project's final subdivision map. The evacuation plan shall include at a minimum the following measures: • Criteria for determining when an emergency exists • Methods for notifying and evacuating area residents • Identification of agencies and individuals responsible for emergency responseand public evacuation • Plans for returning evacuees to their homes after an emergency has passed. Note: Mitigation Measure 3 .7-11 is discussed under next impact. • 3 .7-12 The project site. shall continue to be a part of RD-799 and shall be prohibited from seceding from this district, even if removed from the flood hazard zone by the proposed internal levee system, to provide the district with a continued long-term source of funding for maintenance of the existing RD-799 levee system. Facts: The project site is located in a flood plain. The County General Plan precludes substantial residential development in the area until it is removed from the flood plain. The General Plan permits the construction of internal levees to accomplish this requirement. The project includes an internal levee which will be constructed to Federal Emergency Management Agency (FEMA) standards. The project or its levee will not have an impact on the condition of the existing RD-799 levee. The existing levee can fail with or without the internal levee. The project site provides a safe area for residents outside (and inside) the internal levee if the existing levee fails. The project plans include an evacuation plan (discussed at page 3-137 of the Draft EIR) . The conditions of approval include additional criteria for the evacuation plan. -28- i. The Draft EIR at page 3-137 fully evaluated alternatives to the construction of the internal levee. This discussion included the remediation Of the existing levee. The current estimate to upgrade the existing levee to FEMA urban standards is approximately $20, 000, 000. This does not include costs for environmental review or the costs for removing the existing encroachments on the levee. However, upgrading the existing levee will not remove the site from the flood plain. ;The Contra Costa Canal which is located southwest of the site does not meet FEMA standards. The slopes of the canal will permit the, flow of flood waters in the event the existing levee fails. The applicant has requested RD-799 to accept maintenance of the internal levee. (See Appendix C to the Final EIR. ) Prelimi- nary discussions !ion acceptance have already occurred. If RD-799 accepts the levee, the District will acquire a broader base in which to collect! revenue for the existing levee. Without this additional tax base, the District would not be able to generate enough revenue to upgrade the existing levee. State and federal funds are difficult to obtain due to recent budget cuts. Moreover, the existing residents cannot pay an assessment large enough to generate the needed revenue to rehabilitate the existing levee. Appendix F ;of the Draft EIR contains a report analyzing a possible scenario of a breach in the existing, levee. The report concludes that a;: failure of the existing levee that would cause major flooding is speculative. The report discusses the different causes of a possible levee breach (i.e. , vector damage, heavy rainfall, lack of maintenance) and concludes that such causes are likely to permit adequate time to re-support the levee if a breach is suspected. The report notes that the most common cause of a levee breach on hon-urban levees (such as the existing levee) is due to lack of maintenance and damage by rodents and small animals. Since the existing levee is properly and regularly maintained by RD-799, the levee is not likely to experience this most common cause of levee failure. moreover, since the levee is properly and regularly maintained it is unlikely to. experience a serious levee breach that would put the existing residents at risk. In addition, to the above measures, the applicant will also contribute $25, 000 to RD-799 to be used for special flood control projects (i.e. , additional geotechnical analysis to prepare for the upgrading of the;. existing levee) . The liquef action potential of the site was -thoroughly assessed by Kleinf elder, Inc. Kleinfelder, Inc. has identified various techniques to minimize liquefaction. Such techniques include removal of the: . liquefiable material and recompacting it by conventional means, deep dynamic compaction, vibrocompaction and vibroreplacement.1 soil mixing, pile foundations and slurry wall cutoff and permanent site dewatering. In response to the public's concern on the use of deep dynamic compaction, this method will not -29- be used. Various other methods were analyzed by Kleinfelder, Inc. and shall be followed. Mitigation Measure 3 . 7-8 is modified to reflect this change. Mitigation Measure 3 .7-9 is modified to require compliance. Findings: The Planning Commission adopts Mitigation Measures 3 .7-5 through 3 .7-9 the latter two as modified, and 3 .7-10 and 3 .7-12. The Planning Commission finds that the project plans, the conditions of approval and the above Measures, will mitigate the projectfs potential impact arising from the construction of an internal levee to a level of insignificance. 3 . Impact: The project will have a short-term impact on groundwater as a result of dewatering for excavation of the internal levee, lake, channels and installation of utilities. (This impact is also discussed in the preceding section on Geology, Seismicity and Soils in conjunction with Mitigation Measures 3 .8-3 and 3 .8-6. ) Mitigation: The project includes a groundwater monitoring plan to monitor groundwater levels near adjacent residences during project construction (at page 3-133 of the Draft EIR) . The EIR sets forth the following measure to ensure proper implementation of the groundwater monitoring plan: • 3 .7-11 The proposed groundwater monitoring plan shall be made a condition of project approval. A final groundwater monitoring plan shall be submitted for review RD-79 :and approval by the County prior to filing a final subdivision map. Facts: The project will have a short-term impact on groundwater levels during the excavation activities for the levee, channels and lake. These excavation activities will last for 3-6 months. Since the groundwater is relatively high, its level will require monitoring during these excavation activities. The groundwater draw down will be the greatest for the excavation of the lake. The lake depth is planned for 17 feet so dewatering would not exceed 20 feet. The localized dewatering activities would not affect adjacent properties (the adjacent properties are located approximately 200 feet from the excavation activities) because draw down would only occur on the project site immediately under or adjacent to the dewatering area. To confirm that dewatering activities would not have a significant impact on groundwater levels in the vicinity of adjacent residences, the project plans include a groundwater monitoring program. Mitigation Measure 3 .7-11 is modified to ensure RD-799 reviews the groundwater monitoring plan. -30- Findings: The Planning commission adopts Mitigation Measure 3 .7-11 as modified. The Planning Commission finds that the project plans, in addition to the above Measure (and Measures 3 .8-3 and 3.8-6 discussed 1' in the preceding section) , will mitigate the project's impact on groundwater withdrawal to a level of insignificance. 4. impact Increased surface runoff from the new impervious surfaces and thegolf course may have impacts on the water quality of the channels, ;lake, and ultimately, the Delta. Urban runoff can contain pollutants such as organic pesticides, heavy metals, nutrients, petroleum products, and suspended solids. Mitigation: ] The project 3ect plans include a water quality management plan ; (pages 3-14.0 and 3-141 of the Draft ETR) and maintenance criteria for the golf course (page 3-141 of the Draft EIR) . The EIR sets forth the following measures to ensure adequate water quality islachieved: • 3 . 7-13 . A final maintenance plan for the golf course shall be submitted for review and approval by the County prior to filing a final subdivision map. The final maintenance plan shall build on the maintenance criteria established in the project plans and identify standard maintenance and management practices to be carried out on the golf course. Specific maintenance procedures . shall be identified regarding the use of pesticides, herbicides, and fertilizers. An emphasis of the maintenance plan should be to reduce potential leaching into local groundwater resources The maintenance and management plan shall also outline specific irrigation practices designed to reduce water consumption. • 3 . 7-14: The CC&Rls shall contain information on the use and disposal of undesirable materials such as motor oil, paints, garden pesticides and other household products. • 3 . 7-15, A street sweeping program shall .be provided to reduce urban pollutant runoff into the proposed lake and channels. Street sweeping be provided by the County through its exist Ag" street sweeping program. if- f--easibie, a6lternative measures could include funding of the street sweeping program by the homeowner's association. -31- • 3 . 7-16 A final channel-lake operation and maintenance plan shall be submitted for review and approval prior to filing a final subdivision map. The plan shall be based on. the applicant Is proposed lake-channel management plans utilizing plants, flushing, aeration and other techniques to maintain water quality without chemicals. • 3.7-17 The project shall comply with all the require- ments of the County's NPDES permit requirements. The project applicant shall provide the County with the appropriate documentation regarding compliance with NPDES requirements prior to the issuance of grading permits for the project. Facts: All storm drainage facilities will terminate in the channels or lake. The channels and lake are filled with groundwater. The project plans include mechanisms to periodically clean or flush out the storm drainage pipes (see Draft EIR at page 3-139 . ) This system has been designed so that water quality will be achieved. In addition, the introduction of contaminants into the system will be minimized by the 1) implementation of the maintenance plans -for the golf course, lake and channels, 2) information on the disposal of undesirable materials in the CC&R's, 3) implementation of a street sweeping program; and 4) compliance with NPDES requirements. Mitigation Measure 3 .7-15 is modified to ensure that a street sweeping program is provided. As such, this system will not create a significant impact on water quality. The internal drainage system will keep the drainage on-site other than in a 100-year storm. In such an event, the excess water will be pumped out into Sandmound Slough. This excess water will be "cleaned" as it travels through the internal drain system (discussed above) . In addition, before this water is pumped into the Slough it will comply with NPDES requirements. Findings: The Planning Commission adopts Mitigation Measures 3.7-13 through 3 .7-15 the latter as modified, and 3 .7-16 and 3.7-17. The Planning Commission finds that the project plans, in addition to the above Measures, will mitigate the project's impact on water quality to a -level of insignificance. H. GEOLOGY, SEISMICITY AND SOILS Note: The Mitigation Measures in this section are numbered consistent with those in the Draft EIR and are discussed "out of order" in these Findings. 1. Impact: The project will expose new structures to potential impacts of liquefaction. -32- i Mitigation: The project plans.. include the following mitigation measures to address potential liquefaction impacts: • 3.8-1 Excavate, rework and densify the loose clean and silty sands under the levee to a depth of 10 to 15 feet. if Deep Dynarnie Gempaetien meeed safe limits beyend--ISO-icci green the Famrsayat-i en site t. ..*..a therefore i s t f f i The EIR sets forth the following additional mitigation measures to further mitigate the potential impact on liquefaction to a level of insignificance: • 3 . 8-5 The Kleinfelder report analyzed alternative approaches for mitigating liquefaction impacts and the project seen : be required to adhere to these approaches: The specific approach will depend on site-specific conditions and analysis. However, the project applicant sheu follow the reviewed and approved recommendation of the Kleinfelder report. A report documenting the methods used in the field to reduce liquefaction potential ^ aza--sha11 .be submitted to the Public Works ................... ...... ........ Department and the public agency responsible i for maintenance of the levee system. • 3 .8-8 Building plans for each structure to be constructed on the project site shall include an evaluation and recommendations to ensure satisfactory performance in the event of an i earthquake and liquefaction on the project site. The building plans shall be reviewed and approved by Contra Costa County prior to the issuance of building permits. Facts: Mitigation Measure 3 .8-5 is modified to be mandatory as opposed to optional. The liquefaction potential of the project site was thoroughly assessed by Kleinf elder, Inc. , based on soil borings and other tests conducted for the geotechnical analyses. (This issue wasdiscussed previously with respect to Mitigation Measure 3 .7-8 . ) iThese assessments analyzed techniques to minimize -33- liquefaction. Such techniques include removal of the liquefiable material and recompacting it by conventional means, deep dynamic compaction, vibrocompaction and vibroreplacement, soil mixing, pile foundations and slurry wall cutoff and permanent site dewatering. Due to the public's concern on the use of the deep dynamic compaction method, this method shall not be used. Mitigation Measure 3 .8-1 is modified to reflect this change and Mitigation Measure 3 .8-2 shall not be adopted. As briefly mentioned above, other techniques have been thoroughly analyzed by Kleinfelder, Inc. to mitigate liquefaction. Prior to the building of any structure or facility, a site specific analysis will be- conducted to determine the use of the appropriate liquification method. Findings: The Planning Commission rejects Mitigation Measure 3 .8-2 for the reasons stated above. The Planning Commission adopts Mitigation Measures 3 .8-1 as modified and 3 .8-5 and 3:8-8. The Planning Commission finds that the modified project plans (which include Measures 3 . 8-1 as modified) in addition to the adopted Measures will mitigate the project's potential impacts on liquefaction to a level of insignificance. 2 . Impact: Construction of the project will result in significant grading for the homes, golf course, lakes and other facilities. These activities will expose soils to wind and water erosion. Because the site is located in:an area of strong winds, wind erosion has the potential of: resulting in a significant loss of soil. Mitigation: The project plans include the following erosion control measures to address this impact: • 3 .8-4a. Existing vegetated areas-s;�;i!.62:1 be left undisturbed until constructiori. . ...of site improvements is actually ready to commence. hei i a ................... b. All disturbed areas �-sha1;]: be protected from both wind and water erosion upon the completion of grading activities. C. Runoff= 31 be directed away from all ................... ................... areas disturbed by'construction, if: practical. d. Temporary check dams, sediment ponds, or ................... siltation basins- ' 1 be used to trap ................... ................... eroded soils, and prevent"their discharge into storm drain pipes. e. To the extent possible, major site development work involving earth moving and excavations ..t.,ou a ................... - 1a�11 be scheduled for the dry season. -34- f Areas used for stockpiling and staging construction equipment and materials shau-ld a >1 be located so that unchecked runoff from these areas does not , enter the storm drain i system. The EIR sets forth the following dust control measures to mitigate this impact to an insignificant level: �- Teti at the e•enstruetieir�ite circ—z uzn•• •• a ee e'r el i n �Ce' �P1Te G C[7T-re�t7elTGtiy-ate vu�l✓i u i a a a�..� s., r dust e'eTl"VT-eZ 11TCidd2"Cre'1T-G e7„TVTG['eco"i-s shall lement/ at a / the fellewing a--Sehed-ule—earth?reying -aetiyities, as—rftue'h ag pessible, during the early spring menths w .s6 -meisture is ,iej-h— J- aetivities J L . ePre v i d e-equiprent and staffing f=er watering ..f tiee- / ineluding weekends and hellelays. An apprepri te dust palliative or / add-ed--to—water fie€er ut i 4:i z eel._ d:. Water eineeyexir les of debii8 : l ne er other aterials that ems--be blew WiFid e.. Sweep adjaeent streets ef all mud and debris,-,- ztiu and later resuspended by vehiele traff_j _ while V11 .71 Seed, eever er ehemieally treat finished grad as seen raeti "ori. after eampl e i en of uecivities. Facts: The erosion control measures in Mitigation Measure 3 .8-4 are modified to be mandatory as opposed to optional. Impacts resulting from dust emissions generated by construction equipment were discussed ;under Air Quality. The project plans include extensive dust 'control measures (see Draft EIR pages 3-69 and -35- 4 3-70) . Those measures were further strengthened by the adoption of Mitigation Measures 3 . 3-1 through 3 . 3-4 . To avoid unnecessary duplication and inconsistency,. the dust control measures in Mitigation Measure 3 .8-7 shall not be adopted. The dust control measures in the project plans in conjunction with Mitigation . Measures 3 . 3-1 through 3 . 3-4 are more stringent than those recommended in Mitigation Measure 3 .8-7 . Findings: The Planning Commission rejects Mitigation Measure 3.8-7 for the reasons stated above. The Planning Commission finds that the project plans (which -includes dust control measures and Measure 3 . 8-4 as modified) , in addition to the previously adopted Measures 3 . 3-1 through 3 . 3-4 will mitigate the above impact to a level of insignificance. 3 . Impact: Short-term subsidence may result from dewatering activities during the construction of the levee, lake and channels. (This impact is also discussed in the previous section on Hydrology and Drainage in conjunction with Mitigation Measure 3 . 7-11. ) Mitigation: The following measure is part of the project plans: • 3 . 8-3 Installation of groundwater monitoring wells and settlement plates to provide early detection of changes in the groundwater level and to allow adjustments in the construction techniques if necessary. Monitoring wells and settlement plates t1'; ' be placed on the project site and surrounding properties to control the groundwater level. The EIR sets forth the following additional mitigation measure to reduce the subsidence impact to a level of insignificance: • 3 .8-6 The ground settlement monitoring plan e� a� be finalized and submitted to the County for review and approval prior to beginning any construction or dewatering activities. The plan shall identify the location of all monitoring wells, and provide specifics on well completion and the method and frequency of monitoring. Similarly, the plan shall identify settlement plates as well as contingency plans to control subsidence or mitigate subsidence related damage. Th".-i" .P.. . .. all ..be revseve.: J�;;' RD<-'7::9:9.::x; ....................................::.:.:.:. ..................................................,......::...:.:.............................:::::...: Facts: Mitigation Measure 3 .8-6 is modified to require compliance and to ensure RD-799 reviews the plan. The potential for subsidence from dewatering would be short-term (3-6 months). and would only occur in the immediate area of dewatering activities. -36- Dewatering activities are expected to, occur during the excavation for the lake and channels, construction of the levee and installa- tion of underground utilities. Dewatering activities would effect the top 15 to 20 feet, which would not impact most domestic wells which are below the depth of the dewatering activities. The localized dewatering activities would not cause subsidence on adjacent properties (properties within 200 feet) because draw down would only occur on the project site immediately under or adjacent to the dewatering area. Findings: The Planning Commission adopts Mitigation Measure 3 .8-6 as modified. The Planning Commission finds that the project plans (which include Measure 3 .8-3) in addition to Measures 3 .7-11 and 3 .8-6 will mitigate impacts relating to groundwater activities to a level of insignificance. I. PUBLIC SERVICES 1. Fire Protection Impact: The project will increase fire protection service demands by increasing the number of structures and population within the project area. Mitigation: The project plans include the following measure to address impacts on fire protection services: • 3 . 9-1 The project ;wql; dedicate a site and construct a new fire station on the project site in lieu of fire protection fees as determined by the County. The site and station Sheuld s"R611 meet all applicable requirements ................... of the appropriate Fire District (Oakley FPD or Bethel Island FPD) . The fire station shetllel 111;<`be operational prior to the first homes ................... on the site being occupied. If necessary a special district fee -S;YY21 be augmented to provide adequate funding to fully staff the new station. The EIR sets forth the following additional measures to mitigate fire protection impacts to a level of insignificance: • 3 .9-2 If the project is required to pay fees, the Fire District fees shall be based on the fees in effect at the time of the issuing of building permits. • 3 .9-3 All building plans shall meet the applicable Uniform Building and Fire codes. Fire protec- tion agencies shall be afforded the opportunity to review and comment on plans prior to the issuance of building permits for the project. -37- possible for the District to generate the needed revenue to upgrade the existing levee. In addition, the project applicant will contribute $25, 000 to RD-799 to be used for special flood control projects. One such project is the preparation of an additional geotechnical study to be used in analyzing the upgrading of the existing levee. The Planning Commission finds that the project will provide a greater tax base which will allow RD-799 to. acquire additional revenue to maintain and upgrade the levee. In addition, the Planning Commission finds that the project will assist, through its $25, 000 contribution, the District in continuing its work in upgrading the levee. D. Project Will Provide Needed Improvements to the Cypress Road and Bethel Island Road Intersection. The project plans and mitigation measures include the construction of or contribution toward many needed road improvements. One such improvement is to the intersection of Cypress Road and Bethel Island Road. This intersection is presently at a 90 degree angle, very narrow, and without a stop sign or street light. The. intersection has been the source of many accidents, some of which were fatal. (Final EIR, p. 4-60. ) The project will construct extensive improvements to the intersection as outlined in the Draft EIR at page 3-57, and as schematically shown in Figure 3 . 2-13 at page 3-59 of the Draft EIR. These improvements include, widening of both Cypress Road and Bethel Island Road, designing the intersection with a design speed of 45 MPH, and installation of a traffic signal. The Planning Commission finds that this road improvement is needed for safety reasons, and that there currently are no other potential sources of County funding for the improvement given current and projected budget and revenue conditions. E. Project Will Dedicate Fire Station Site and Construct a Fire Station. The project will dedicate a fire station site and construct a fire station at the project entrance at Cypress Road and Bethel Island Road. This facility will allow the fire districts to achieve the County policy of a maximum running time of three minutes and/or 1. 5 miles from the station to development. (General Plan, Policy 7 . 62 at page 7 . 46. ) Presently, there is only one fire station in the Bethel Island Area which is located two blocks north of the bridge. There are two stations in Oakley. (Draft EIR, at page 3-164 . ) Due to the distance between these stations, the fire districts cannot maintain the County's policy regarding response time. The station proposed -78- by the project will be near the center of the boundaries of the existing stations. The Planning Commission finds that the new fire station is necessary to attain the County policy requiring fire stations to be located within one and one-half miles of development. F. Recreational Amenities Provided By. the Project. The off-island portion of , the Bethel Island Area is the only area in the General Plan with a residential/recreational land use designation of this kind. The concept for the area, as it applies to the site, is to provide opportunities for recreational oriented residential growth. This growth is intended to enhance the recreational quality of the area. (General Plan at pages 3-54 through 3-56. ) The General Plan includes an "Off-Island Bonus Area" overlay designation. The underlying designation for the site is "Agricultural Lands" which allows 1 unit per 5 acres. This base density can be increased up to 2 . 9 units per acre through the overlay designation if the project includes substantial recreational facilities. Recreational facilities can include marinas or launching areas, a lake community, a sailing/boating club on a project lake, an equestrian facility, a tennis club or golf course. (General Plan, page 3-30. ) Consistent with the overlay designation, the project is a lake community that includes an 18-hole golf course with a club house and driving range, a community park, several water channels, a beach and tennis 'club and extensive pedestrian and bicycle trails. (Draft EIR, pages 1-4 through 1-8 . ) These recreational amenities are consistent with the overlay designation and its intent, namely to enhance the recreational quality . of the area. The project's recreational amenities are open to the public. Currently, there are limited recreational opportunities of the sort offered by the project in the Bethel Island Area and eastern part of the County. This project with it amenities is a beneficial impact. The Planning Commission finds that the project's recreational amenities will enhance the unique recreational character of the area and will offer recreational opportunities to the population of the eastern part of the County. -79- Facts: To reduce the project's impacts on fire services, the project plans include a fire station near the project entrance at Cypress Road. This station will satisfy the County's standard that fire stations be located within one and one-half miles of develop- ment. The project plans, as identified in Mitigation Measure 3.9-1, shall be modified as reflected above. The project site is located within both the Oakley Fire Protection District and the Bethel Island Fire Protection District. The project applicant is in the process of requesting LAFCO to consolidate these Districts. Consolidation will eliminate 'confusion as to the District lines and allow for more efficient service. Findings: The Planning Commission adopts Mitigation Measures 3.9-2 and 3 .9-3 and directs that the project plans incorporate the modifications made to Measure 3 .9-1. The Planning Commission finds that the modified project plans in addition to the above adopted Measures, will mitigate the impact on fire protection services to an insignificant level. 2 . Police Protection Impact: The project will result in the addition of approximately 3 , 247 persons within the County Sheriff's service area. This will result in the need for new officer positions and equipment. Mitigation: The EIR sets forth the following measure to ensure the project provides its fair share toward the cost of rehabilitating the Delta Station in Oakley: • 3 . 9-4 The proposed project—s ' '` ' pay a fair- share fee equal to the cost of.. providing 465 square feet of new Sheriff Department facilities, based on the County standard of 155 square feet per 1, 000 residents. The fee �shall be calculated and paid at the time ........................ .. ........... of issuance of building permits for the project. Facts: With an estimated population of 3 , 247 new residents at build-at, the project will need to provide approximately 465 square feet of additional space to maintain the County's adopted standard of 155 square feet per 1, 000 population. Mitigation Measure 3 .9-4 is modified to require compliance with this standard. The project will be consistent with the criteria in the General Plan by contributing monies for the expansion of the Delta Station in Oakley as recommended in the above Mitigation Measure. Findings: The Planning Commission adopts Mitigation Measure 3.9-4 as modified. The Planning Commission finds that this Measure will reduce the project's impact on police protection to a level of insignificance. -38- 3 . School Impact: The project will generate approximately . 665 new elementary and middle school enrollments and approximately 253 new high school enrollments. . Mitigation: The EIR sets forth the following measures to mitigate the project's impact on schools to a level of insignificance. • 3 .9-5 The application and the school districts shall X. enter into a short-term funding agreement prior to recordation of the final map. The agreement s'^nu'rizf7L'Id ensure that matching fundings are provided: for the completion of construction documents necessary for the district's application(s) for stat funding. The amount of short-term funding would be credited to the applicant's full school impact fees which are paid upon issuance of building permits. • 3 .9-6 School impact fees are projected to be insuffi- cient to cover the project's share of facilities required to serve new students in the area. If no state or local funding is available the applicant 5' T ( llt......... ' > :. :.::::::::::::::::::: skeuld work with the school districts to determine additional school feesth be paid as building permits are issued. .................. 6d h • 7 :f:<;:>re u1:red:€:::<:is3 ;;>::<:tie< a]c........ ..............................................................::. rt` > Ph:e:::...scriool......st.e.:....9nea ....�e enlarged from 7 . 4 acres to 10 acres the • 3 .9-8 If the proposed on-site school site is determined by the OUSD to be unacceptable, the applicant shall pay an in-lieu fee to the OUSD for the purchase of an appropriate school site. Facts: The project falls within the Oakley Union School District for kindergarten through 8th grades, and Liberty Union High School District. Based on the project's student generation and the local school district's school facility requirements, the project will require the construction of approximately one new elementary school, 30% of a new middle school, and 20% of a new high school. With the recent adoption of Senate Bill 1287, the maximum school impact fee that can be imposed on the project is $2 . 65 per square foot. The project applicant proposes to dedicate a elementary school site of 7 . 4 acres in lieu of paying school impact -39- fees. If it is determined that the property value of the site is less than the fees that could be imposed, the school district shall require the applicant to pay the difference in fees. . Mitigation Measure 3 .9-7 states that the site should be enlarged to 10 acres. This Mitigation Measure is modified to require enlargement of the site only if required by the District. A larger site can be accomplished by redesigning the loop roadway and reducing the number of units south of Cypress Road or through the acquisition of neighboring parcels. If a 10 acre site cannot be provided, then the applicant shall pay the applicable fees. If school impact fees will be paid, the County cannot require the applicant to enter. into a short-term funding agreement as mentioned in Mitigation Measure 3.9-5. In addition, the County cannot require the applicant to pay fees in addition to those required by State law as identified in Mitigation Measure 3 .9=6. State law requires that the fees be paid at the issuance of building permits. School impact fees are controlled by State law, and the locality is without power to require any additional mitigation measure. As a result, Mitigation Measure 3 . 9-5 is modified to reflect that a short-term agreement may be entered into and Mitigation Measure 3 . 9-6 is modified to encourage, but not require, the applicant to contribute additional funding. Findings: The'Planning Commission adopts Mitigation Measures 3 .9-5 through 3 .9-7 as modified and Mitigation Measure 3.4-8. The Planning Commission finds that these Measures will mitigate the project's impact on schools to an insignificant level. 4. Parks and Other Recreational Facilities Impact: The project will have a . beneficial impact on parks and other recreational facilities.. The project includes a 170 acre semi- private 18-hole golf. course, 60 acres of water channels and a lake, a beach and tennis club, approximately 33 acres of public and private parks, a wetland mitigation area, a day care facility, and pedestrian/bicycle trails. Mitigation: The EIR sets forth the following mitigation measure to ensure. proper maintenance of park facilities: • 3 . 9-9 The project construct and dedicate the large community park to the County which would then be responsible for continued maintenance of the park. If this is unacceptable to the County, funding for maintenance of the community park sheuh l' be provided through a special district. The EIR sets forth the following mitigation measure to ensure that the design of .the. community park reduces . potential conflicts with the power line easement: -40- • 3 . 9-10 The community parks be designed so that active recreational us'e areas are located outside the power line easement. Active uses include: baseball diamonds, soccer fields and play ground areas. Uses permitted within the easement shatilel -'sha be passive recreation and landscape areas The EIR sets forth the following measure to ensure that the child care facility proposed by the applicant is adequate to serve the demand generated by the project: • 3 .9-11 The project applicant shall. prepare a child care needs assessment based upon the projected demographics . and density of the proposed project. The needs assessment. shall be submitted to the Community Development Plan prior to approval of the final phase map for the portion of the project which includes the day care site. Facts: The project is being processed under the overlay GeneralPlan land!use designation of "Off-Island Bonus Area." This designation permits 1. 0 to 2 .9 dwelling units/acre, depending upon the amount of recreational amenities offered by the project. Thus, a higher density will be permitted for projects that include substantial recreational amenities. The project includes a density of 2. 21 units/acre. The recreational amenities offered by the project fully support this density and will provide a beneficial impact to the area with the implementation of the above measures. Mitigation Measure 3 .9-9 through 3 .9-11 are modified to ensure compliance. Findings: The Planning Commission adopts Mitigation Measures 3 .9-9 through 3 .9-11 as modified. The Planning Commission finds that the project plans, in addition to these Measures, will create a beneficial impact with respect to park facilities and other recreational facilities. 5. Mosquito Abatement Impact: The lake, channels, golf course and wetland mitigation area can lead to mosquito problems year round. Mitigation: The. EIR sets forth the following . measure to mitigate this impact to a level of insignificance: • 3 .9-12 . The Contra Costa Mosquito Abatement District ("CCMAD") hall be provided the f inal design plans for wetYand mitigation areas and golf course maintenance and irrigation for review and comment prior to plan approval. -41- Facts: The lake and water channels have been designed with steep slopes and adequate depth to minimize potential mosquito populations. In addition, the water level shall be kept constant to avoid the production of mosquitos. The project plans include a water quality management plan which addresses this impact (see pages 3-140 and 3-141 of the Draft EIR) . The design of the lake and water channels, along with the water quality management plan, will mitigate the mosquito impact to a level of insignificance as it relates to the lake and water channels. No additional mitigation is necessary. With respect to the golf course, the project plans include golf course maintenance criteria which will reduce the potential for mosquito growth (see page 3-141 of the Draft EIR) . Mitigation Measure 3.9-12 is modified to ensure that potential mosquito growth is brought to an insignificant level with respect to the golf course and wetland mitigation area. Findings: The Planning Commission finds that no further measures than those already contained in the project plans are necessary to mitigate the mosquito impact with respect to the lake and water channels to an insignificant level. The Planning Commission adopts Mitigation Measure 3 . 9-12 as modified. The Planning Commission finds that the project plans, in addition to the above Measures, will reduce this impact to an insignificant level with respect to the golf course and wetland mitigation area. J. UTILITIES 1. Water Impact: Development of the project will increase water demand for the site and require annexation to a water district. The project will use groundwater for irrigation and non- domestic uses and treated water from the Oakley Water District for domestic uses. Mitigation: The EIR sets forth the following measure to monitor effects on the groundwater table as a result of irrigation and to avoid potential impacts due to groundwater withdrawal: • 3 . 10-1 Implement a groundwater management plan to address water requirements for irrigating the golf course and parks and to monitor changes in the groundwater table. The groundwater management plan - 1 also address the management of pesticides...arid measures to be taken to reduce potential impacts on groundwater resources. In addition, the plan shatild sk` ' 3 identify what areas, and in what sequence, water will be discontinued to portions of the golf course and parks in the event of water cutbacks because of drought or substantial lowering of the water table. The -42- plan should sh; 1;1 be approved by the County prior to filing a final subdivision map. The EIR sets forth the following measures to reduce the project's water consumption demand: • 3 . 10-2 Design into the golf course the use of grasses that are drought tolerant to limit the amount of water necessary for irrigation. • 3 . 10-3 Require all structures to confirm to the California Health and Safety Code Section 1792 . 3 and the Public Resources Code Section 25402 with regard to maximum flow rates through plumbing fixtures. • 3. 10-4 Provide homeowners with alternative landscaping opportunities such as xeriscape landscaping for builder installed front yards. • 3 . 10-5 . Design water distribution systems in accordance with American Water Works Association standards. • 3 . 10-6 , Install cathodic protection where corrosive environments are found, and use metallic water line products. • 3 . 10-7 - Install cathodic protection where corrosive environments are found and metallic water line products must be used. The EIR sets forth the following measure to ensure that off- site water improvements are installed to serve the project: • 3 . 10-8 The project should be required to construct, or pay a fee equal to, . the necessary off-site water system improvements to serve the proposed project. The size and design of these facilities sheulds; l meet all applicable standards and requirements of the Oakley Water District and local Fire District Standards. The project eheuzd '1'a be reimbursed on a proration basis for the �cost of constructing facilities which have the capacity to serve future development in the Planning Area served by the facilities. The necessary off-site water facilities �d—;sk s1 be completed and operational prior to the first homes being occupied on the site. -43- Facts: Water requirements for the project would amount to approximately 1.7 million gallons per day (mgd) ; 884 , 150 mgd for domestic use and 805, 200 mgd for landscaping. The project is proposing to utilize existing groundwater resources for irrigation of the golf course, parks, wetlands, and certain levee areas. The Oakley Water District is the logical provider of domestic water service to the project and has provided a "will serve" letter to the project applicant confirming that water capacity is available to serve this project through its buildout. The EIR also confirms that the District has adequate capacity to serve the project. Mitigation Measure 13 . 10-1 is modified to require that the Groundwater Management Plan contain the criteria in the Measure and be approved by the County prior to the filing of the final subdivision map. The applicant is in the process of requesting annexation to the Oakley Water District. As required by the modifications in Mitigation Measure 3 . 10-8 , the design and size of all improvements shall meet the requirements of the Oakley Water District. Findings: The Planning Commission adopts Mitigation Measures 3 . 10-1 as modified, and 3 . 10-2 through 3 . 10-8, the latter as modified. The Planning Commission finds that the project plans, in addition to the above Measures, will mitigate the project's impact on water to an insignificant level. 2. Sewage Disposal Impact: The project will result in a significant increase in wastewater generated from the project site. Based on wastewater generation factors provided by the Oakley Sanitation District, the project will generate approximately 360, 000 gallons/day (or 0. 36 mgd) based on 270 gallons/unit day x 1, 330 units. The project will require partial annexation to the Ironhouse Sanitary District. Mitigation: The EIR sets forth the following measure to ensure that adequate on-site sewage collection facilities are provided: • 3 . 10-9 The project applicant 'sha1 be required to construct all necessary sewage collection facilities on-site to serve the project. These facilitiessheuld— . ail be built to district .................. ................... standards and appropriate easements for district maintenance provided. The sewage collection facilities shetild- 'ha"'1 i be installed ................... .................. prior to the first homes being occupied. The EIR sets forth the following measures to ensure adequate off-site improvements are provided: -44- • 3 . 10-10 A hydraulic analysis of the force main s -l-d 7 be conducted to determine the capacity of` tfie existing force main and any improvements that may be necessary to accommodate the proposed project. This analysis slte - be conducted prior to approval of the prof s. final subdivision map. The project shall pay its :fair share of any improvements necessary to the force main to serve the project. The fair share fee shall be paid upon approval of the first phased map. • 3. 10-11 The project IIsi- } be required to pay the full costs of any 'increase in pumping capacity or new pump station(s) necessary to serve the project. The need and cost for these improvements shall be determined by the Ironhouse Sanitary District prior to approval of the final map. • 3 . 10-12 A reimbursement agreement shall be entered into between the project applicant and the Ironhouse Sanitary District whereby the project applicant would be reimbursed for the. portion of the cost of new facilities which have the capacity to .. serve areas in addition to the project. The reimbursement weal: be paid out of fees paid by future developments. Facts: The logical- provider of sewer service for the project is the Ironhouse Sanitary District because 750 of the project site is located within its existing service boundaries. The project applicant has requested that the remainder of the project site be annexed to the Ironhouse Sanitary District. The Ironhouse Sanitary District has adequate capacity to serve the project and has provided a "will serve', letter to the project applicant. The District has a current treatment capacity of 2 . 3 mgd and disposal capacity of 2 .9;mgd. Of this capacity, 0.7 mgd is currently unallocated. The 0.7 mgd is sufficient to serve 3, 000 units. Mitigation Measure 3 . 10-9 is modified to require that the on-site facilities are built to the Districts standards and prior to the first home being occupied. There may be several off-site improvements necessary to serve the project. The District is currently improving their facilities and some of the '. necessary improvements may already be installed before the project is built. Consistent with the above Measures as modified, if needed, the developer will work with the District to provide :the improvements and will receive credit or reimbursement for the improvements. -45- Findings: The Planning Commission adopts Mitigation Measures 3 . 10-9 through 3 .10-12 as modified. The Planning Commission finds that the project plans, in addition to the above Measures, will reduce the project's impacts on sewage disposal to a level of insignificance. 3 . Electrical Service Impact: Electric service will be supplied to new development by PG&E. The existing transmission lines and substation have adequate capacity to provide service to the project. Mitigation: The project plans include the following measure as required by the General Plan: • 3 . 10-13 Underground all new electrical service lines necessary to serve the project site. Electrical lines will be placed in relatively water tight conduits according to PG&E standards. This sheidid S; l-1 be completed prior to the first houses being occupied in that particular phase. The EIR sets forth the following additional measure to ensure consistency with the General Plan: • 3 . 10-14 The need to upgrade off-site electrical lines shall be determined by PG&E prior to approval of the final map. If 'off-site reinforcement is necessary, the project applicant Sheldld a# a 1- be required to pay the project's fair ................... share, if any, of the reinforcement. Facts: Mitigation Measure 3 . 10-13 is modified to require undergrounding of the lines during each phase. Mitigation Measure 3. 10-4 is modified to require the applicant to pay its fair share of the reinforcement. Findings: The Planning Commission adopts Mitigation Measure 3 . 10-13 and 3 . 10-14 as modified. The Planning Commission finds that the project plans (which include Measure 3 . 10-13) in addition to Measure 3 . 10-14, will ensure that the project's impacts on electrical services are kept to a level of insignificance. 4 . Telephone Service Impact: The project will require the replacement of the switch on Bethel Island and the extension of new telephone cables to the project site. Mitigation: The EIR sets forth the following mitigation measures to ensure the proper expansion and design of telephone facilities: 3 . 10-15 Place distribution lines underground. -46- • 3 . 10-16 Install telephone cables in relatively watertight conduits and vaults. Facts: According to PUC regulations, costs of line and equipment installation will be borne by the developer and Pacific Bell. According to County policy, distribution lines will need to be placed underground in relatively watertight conduits and vaults, thereby avoiding. visual impacts and prolonging the life of the equipment and cables. Findings: The Planning Commission .adopts Mitigation Measures 3. 10-15 and 3 . 10-16. The Planning Commission finds that the above measures will ensure that the project's impact on telephone service is kept at an insignificant level. 5. Street ! Lighting Impact: The project includes street lighting and additional lighting associated with individual resi- dential units and recreational uses. Street lights produce a "glow" which could impact adjacent residents. Mitigation: , The EIR sets forth the following measure to reduce the glare from street lights: • 3 . 10-17 Project street lightsoulesh:all utilize down focused lights and other features to reduce glare. The design of street lights mel -.U; be submitted for review and approval to the County Public .Works Department for review and approval prior to approval of the final map. Facts: The street lighting would be installed in accordance with Contra Costa County Code (Title 9) requirements and maintained by Contra Costa County. Mitigation Measure 3 . 10-17 is modified to ensure compliance. The implementation of the above measure will reduce the above impact to a level of insignificance. Findings: The Planning Commission adopts Mitigation Measure 3. 10-17 as modified. The Planning Commission finds that this Measure will reduce the project's impact with respect to street and additional lighting to a level of insignificance. R. HUMAN HEALTH 1. Impact: The Draft .EIR stated that residents of the project could be exposed to agricultural chemicals applied aerially on nearby agricultural lands. Mitigation:' The Draft EIR sets forth the following measure to notify new residents of adjacent agricultural aerial spraying: -47- 3 , , - ueb remielenee—an the prej eco—site she ,a n e l u-dein its GG9 a e3atis eensisteent with ee die lesure eurrently required by the Geuiij stating that the ..Ej preperty ewner Is aware o€—adaeent a rieultura —uses and the petential hazards i-elated to this land use. Facts: In response to comments on the Draft EIR, the potential impact identified above was re-evaluated. (Final EIR, p. 4-131 and Appendix B. ) Through this re-evaluation it was determined that the impact was not potentially significant. Pesticide applications have not occurred on or near the project site since 1984 . The area is mainly used for cattle grazing which aerial application of pesticides does not occur. Increased spraying will not occur since this site, in addition to some adjacent sites, are currently proposed for urban development. Inquiries of long-time existing residents indicate that aerial spraying rarely occurs and is not a problem. (Bob Gromm, Dave Dal Porto. ) Moreover, the use of agricultural spraying is strictly regulated by County and State regulations. The purpose of the regulations is to prevent significant impacts that may result from such spraying on nearby residents. For these reasons, the potential for significant impacts to project residents from aerial application has been identified as remote and less than significant. Findings: The Planning Commission rejects Mitigation Measure 3. 11-1 for the reasons stated above. The Planning Commission finds that the potential impact to project residents from aerial applications is less than significant and no mitigation or notification of the impact is necessary. 2 . Impact: The project site could potentially contain contaminated soils in areas where heavy equipment is stored, and where repair facilities and above-ground storage tanks are located. Mitigation: The EIR sets forth the following measure to mitigate the above impact to a level of insignificance. • 3 . 11-2 Conduct soil sampling in areas of the site where heavy equipment is stored and where repair facilities and above-ground storage tanks are located. If soil contamination is identified, removal and remediation of the ,.1, ,i a � material �-.%ha' J: occur before excavation or construction "actvities commence in these areas. The Contra Costa County Health Department shall supervise and authorize any soil sampling procedures and remediation. -48- Facts: The above measure is modified. to be mandatory as opposed to optional. This measure as modified will ensure that soil contamination, if any, on the site will be removed prior to the commencement of construction activities. Findings: The Planning Commission adopts Mitigation Measure 3. 11-2 as modified. The Planning Commission finds that this Measure will reduce the above potential impact to a level of insignificance. 3. Impact: The project will involve the construction of lakes, a golf course and other water-related facilities including a wetland mitigation, site and drainage facilities. These facilities may provide breeding habitat for mosquitos if not properly maintained. Mitigation: The EIR sets forth the following measures to reduce the potential mosquito population and associated health risks: • 3 . 11-3 The Contra Costa Mosquito Abatement District (CCMAD) t1id gh 1�I, be consulted regarding mosquito abatement --features during the final design of any wetlan,d mitigation area to be created on the project site. A reelaimed water ±9, used fer reereatiena-1 areas, GeMAD should be* eansulted regarding -the ign and testing .ef alternative metheds a disbursement seurees— Facts: This impact .was previously discussed under the Public Services Section - Mosquito Abatement Impact. That discussionis .. incorporated herein by this reference. Mitigation Measure 3 11- 3 is modified to. ensure that CCMAD is consulted on the design of the wetland mitigation area. The project is not , proposing to use reclaimed water. Groundwater will be used for irrigation .and other non-domestic uses (see discussion under Utilities - Water Impact. ) As a result, Measure 3. 11-4. is not necessary, Implementation of Measure 3 . 11-3 as modified, in addition to Mitigation Measure 3 .9-12 discussed previously, will mitigate the potential human health risks associated with mosquitos to a level of insignificance. Findings: The Plan-ning Commission adopts Mitigation Measure 3 . 11-3 as modified. The Planning Commission rejects Mitigation Measure 3 . 11-4 for the reasons stated above. The Planning Commission finds that Measure 3.11-3, in addition to - Mitigation Measure 3.9-12f will reduce , this impact to' a level of insignificance. -49- 4 . Impact: The project site is located in close proximity to large electrical transmission lines and natural gas drill easements (no active gas sites) . . Risks associated with these uses are speculative and are not considered a potentially significant impact. Mitigation: The EIR sets .' forth the following measure to provide new residents with information regarding human health issues relating to electrical lines and non-active drill sites: • 3 . 11-.5 Each residence within the project site sketild >1 include in the CC&Rs a clause stating "A""the incoming property owner is aware of the specific human health issues related to living near electrical transmission lines and drill sites. Facts: The site contains two PG&E 500 kV lines, one USA 230 kV power line and a 200 foot wide easement for a Western Area Power Administration 500 kV power line (this latter line is intended to result in the removal of the USA power line) . The lines are located in' the middle of the easements. The easement widths provide a sufficient buffer to reduce exposure to electro- magnetic fields. Numerous epidemiological studies have been performed to determine associations between exposure to electro- magnetic fields produced by not only power lines but household wiring, electrical appliances` -and various medical disorders such as cancer, birth defects, developmental abnormalities and various neurological effects. These studies do not prove that electro- magnetic fields causd'-`medical disorders. As more thoroughly explained in the EIR, studies and research performed to date are not conclusive on the potential health affects of electromagnetic fields. Due to inconclusive studies and research, California does not have any standards for exposure to electromagnetic fields or siting criteria for residential development near -power lines. The possible impact of electromagnetic fields is speculative and isnot considered significant. However, due to the recent public awareness on this issue the project CC&Rs shall mention the possible health issues associated with power lines. The gas drill sites on the project are not active. Gas has never been found in this area and there are no known gas resources in the area. However, to fully inform new residents of the,. sites, the CC&Rs shall identify their location. Mitigation Measure 3 . 11-5 is modified to ensure that the CC&Rs include the above information. Findings: The Planning Commission finds that the issue relating to health risks associated from the power lines is speculative. As permitted by CEQA, no further discussion of this issue is necessary from what is already contained in the EIR. -50- (Guidelines § 15145. ) The Planning Commission also finds that the project does not , create significant' health risks associated with the gas sites because they are not active. The Planning Commission adopts Mitigation Measure 3 . 11-4 as modified to notify new residents of human health issues related to living near power lines and gas sites. L. CULTURAL RESOURCES 1. Impact:; The project site is known historically to contain cultural;. resources, including the possibility of human burials. As such, the project may result in the disruption of cultural resources as a result of the grading and excavation necessary to construct various components of the project. Mitigation: The EIR sets forth the following measures to ensure long-term avoidance and preservation of cultural resources that may be present on the project site: • 3 . 12-1 Due to the existence of subsurface cultural materials along the western perimeter of the CA-CCo-134 site area and the recommendations relative to site CA-CCo-139 (below) , it eeemmended that significant ground disturb- ance s2 611 be avoided in an area of ...... .......... approximately 11 acres. The proposed uses in this area (internal levee, natural gas drilling site, fire station, community park) are not expected to result in significant ground disturbance. However, all construction activity in this area srivurc3':: .. be closely monitored to preserve known resources and to determine the presence of any previously unknown subsurface resources in the CA-CCo-134 area. Should sterile soil (e.g. , topsoil) be . placed over the site for landscaping purposes, it is reeemmended that rubber-tired construction vehicles sha11 be used throughout ................... the site area and €Yta excavation for landscaping or irrigation shall be -��a ti s".1";ed in fill material only. Should it be necessary to excavate through native soils, an archaeologist sheu=d—sh.411 be present to monitor soil removal for the presence of cultural materials. • 3 . 12-2 Significant ground disturbance slewt� -be- avoided e avoided in the area surrounding .... `..site CA-CCo-13 9, from the 0-foot (sea level) contour to the mound apex at 6. 5 feet above sea level. The proposed uses in this area (community park, extension of Cypress Road) are not expected to -51- result in significant ground disturbance. However, all construction activities sheulel s :1 be closely monitored to preserve known resources present in this area. It is understood that two private parcels of land on the mound are not included in the project proposal. These recommendations do not apply to those parcels unless they are incorporated into the project proposal at some future time. Should any subsurface disturbance. occur on the mound through the removal of structures or foundations, an archaeological monitor should sU ;I . . 1 be present to observe soils for the ................................. presence of cultural materials. Should sterile soil (e.g. , topsoil) be placed over the site for landscaping purposes, it reeemmend that rubber-tired. construction vehicles ..: ................... ................... ................... be used throughout the site area and that excavation for landscaping or irrigation 13 > be allowed— T zed in fill material only. ......................::.... ............................. Should it be necessary to excavate through .................. native soils, an archaeologist � -sha':Tl be present to monitor soil removal for the presence of cultural materials. • 3 . 12-3 Construction at the fire station, which would be within the area of archaeological sensitivity for site CA-CCo-139, =s.z1 be closely monitored and work stopped immediately if cultural materials are encountered. If it is determined that construction is not feasible, the project applicant shall be required to find an alternate site outside the archaeologically sensitive area. • 3 . 12-4 Lot No. 10 in Neighborhood 1 she'd1d ; be removed or redrawn in a manner that avoids the archaeologically sensitive area associated with CA-CCo-139 . • 3 . 12-5 Lot No. 11 in Neighborhood Ill be removed or redrawn in order to avod......the archaeologically sensitive area associated with CA-CCo-139 . • 3 . 12-6 The area including and immediately surrounding site CA-CCo-647 ha'I7 be avoided to ................... ................... ................. preclude impacts to this important resource (see Appendix H) . Should sterile soil (e.g. , topsoil) be placed over the site for landscaping purposes, it is reeemmended that -52- rubber-tired construction vehicles11a ; ; be used throughout the site area and that excavation for landscaping or irrigation a be allewed .' z ;ti : in fill material only. Should it be necessary to excavate through ................... native soils, an archaeologist ia1; be present to monitor soil removal for....... the presence of cultural materials. • 3. 12-7 . The rear lot lines of lots No. 29 and 30 in Neighborhood 7 shem-d a ;� be redrawn in a manner that avoids the....: archaeologically sensitive area associated with CA-CCo-647. • 3 . 12-81 In the event that avoidance of the preceding cultural resource sites is not feasible, a data recovery or "excavation plan" pursuant to the requirements of 'CEQA Appendix K, Part V and subject to the limitations defined in Part VI . • 3 . 12-9 An archaeological monitor should . be be present when grading, excavation, trenching and other soil disrupting activities are carried out in any of the mapped archaeologically sensitive areas as defined in Appendix H of the Draft EIR. These activities/areas include, for example, the Cypress Road extension; levee construction/excavation/compaction; possibly, demolition of existing homes; fire station construction; and the parking lot for the playing fields. ................... • 3 . 12-10 An archaeological monitor old 9' a::. be on- call when grading, excavation, trenching and other soil disrupting activities are carried out on the project site. In the event that a prehistoric site, burial, or historic resource is encountered during construction of the ................... project, the project engineer amara—shall be obligated to temporarily stop or relocate construction activities and notify the archaeological monitor immediately. In the event a significant prehistoric or historic resource is identified, no further construction eheu al. be permitted in that location until a mitigation plan can be formulated and implemented. • 3 . 12-11 In the event human remains are discovered during construction, excavations l7r�- ' be halted at that location. Any finds of human -53'- remains must be. reported to the Contra Costa County Coroner's Office. In the event that the find is determined to be prehistoric, the Native American Heritage Commission must be notified within 24 hours to alert them of the find and to permit the designation of a Native American representative. Consultation between the archaeological consultants in charge of monitoring, Contra Costa County, and the Native American representative weuld ON.................. then ................... ................... determine the course of action to be taken with the burial in question. Ideally, if removal is undertaken, timea> be allowed for study of the remains and any associated grave goods prior to their return to the Native American Community for reburial at a location of their selection. • 3 . 12-12 A report of findings and analyses of all archaeological data recovered during testing/excavation, monitoring and any .......... ...... mitigation procedures undertaken h ba1... 1 ................... ................... be prepared by a qualified archaeologist. • 3 . 12-13 Sections 5097 .98 and 5097 . 99 of the Public Resources Code also call for "protection to Native American human burials and skeletal remains from vandalism and inadvertent destruction. " To achieve this goal, it is reeemmendedthat the personnel on the project be 5 ':a' instructed as to the potential for discovery of cultural or human remains, and both the need for proper and timely reporting of such finds, and the consequences of failure thereof. • 3 . 12-14 It is reeernmended—thatThe Native American Heritage Commission (NAHC)...in Sacramento fi':a:1'1 .................:. be contacted regarding potential Native American concerns, values, and traditional use areas relative to the proposed project site and vicinity. There is a potential for disturbance of previously undiscovered Native American human remains during construction of the project. an established agreement al3beri 'd>aa with the NAHC and/or local.......Bay M woke tribal representatives prior to the discovery of such remains, should any be discovered. A typical agreement would specify when, in the event of a discovery, Native American involvement would -54- occur, and the treatment and ultimate disposition of ancestral remains. • 3 . 12-15 The proposed intersection improvements at the project entrance and Bethel Island Road sheuld 3I>.. be realigned to the north as much as ................... possible to avoid impacting site CA-CCo-138. • 3 . 12-16 . The alignment of any future extension of Bethel Island Road south of Cypress Road sheuld s be as far east as feasible to avoid site CA-CCo-138, taking into consideration safety .-factors. This may result in the need to move the project levee along the project's westerly boundary up to 50 feet to the east. Facts: All the Mitigation Measures above are modified to ensure compliance. As indicated by the above . measures and the project plans, the project would avoid or provide for uses which would be considered appropriate for areas which are archaeologically sensitive. This is consistent with the General Plan. Findings: The Planning Commission adopts. Mitigation Measures 3 . 12-1 through 3 .12-16 as modified. The Planning Commission finds that these Measures, in addition to the project plans, will reduce the project's potential. impacts on cultural resources to a level of insignificance. M. ENERGY 1. Impact'.. The project would increase the amount of energy expanded for commuting when compared to other residential develop- ments closer to urban/job centers. Short-term consumption of energy for construction is not considered significant as explained in the Draft EIR at page 3-233 . The development will increase the need for energy consumption through domestic consumption. Mitigation: The project plans provide the following to reduce energy consumption: • 3 . 13-1 Building plans for each house will include energy conservation features such as passive solar heating, additional insulation and other features so that Title 24 efficiency standards (1991) will be exceeded by at least 10%. These features shall be reviewed and approved by the County Building Department as part of the building permit review process. -55- Facts: The project's impact on the jobs/housing balance is discussed in the Land Use Section of these Findings. As stated above, the project plans commit to incorporating design features so that energy consumption would be reduced. Findings: The Planning Commission finds that the project will not have a significant impact on the consumption of energy for construction. The Planning Commission finds that the project plans (which includes Measure 3 . 13-1) will reduce the project's potential. impact on domestic energy consumption to a level of insignificance. III. DISCUSSION OF PROJECT ALTERNATIVES Pursuant to CEQA at Section 15126(b) , the EIR includes a comparative analysis of a reasonable range of alternatives to the project, which could feasibly attain the basic objections of the project. The EIR analyzes seven alternatives as summarized below. A. NO PROJECT ALTERNATIVE Facts: CEQA Guidelines at Section 15126 (d) require that the specific alternative of "no project" be evaluated in the environmental document. The Draft EIR discusses this Alternative at pages 4-2 through 4-4 . Under this Alternative, development would be limited to existing uses- and the property would remain in its current setting. The No Project Alternative would avoid changes to the existing environment which would be caused by the project. These changes generally include the following: 1. Conversion of generally undeveloped land to residential/recreational uses; 2 . Increased traffic; 3 . Changes in air quality; 4 . Loss of existing vegetation and impacts on wetlands; 5. Changes in the visual character of the site through the introduction of new residential/recreational uses and internal levee; 6. Increased noise levels in the project area; and 7 . Expansion of public services and utilities. This Alternative would substantially reduce or avoid many of the impacts of the project. However, as identified in these Findings, most of the impacts of the project can be mitigated to less than significant levels through the implementation of the project plans and mitigation measures. -56- The No Project Alternative has the potential of creating the following significant impacts. The following also identifies some of the benefits of the project. 1. Continued agricultural use could adversely affect cultural resource sites. The project will preserve the sites in their existing condition. 2. The proposed storm drainage improvements would not be constructed as part of -the No Project Alternative. Therefore, the beneficial impacts on RD-799 drainage facilities associated with the proposed project would not occur. 3 . The No Project Alternative would not provide for the potential to improve water quality in Sand Mound Slough as would occur under the project. 4 . Under the No Project Alternative, an internal levee system would not be built and the existing residents would not be provided with a closer evacuation site in the event of a breach and resulting flood on the existing levee. The No Project Alternative would not provide certain benefits which come with the project, such as those mentioned above. Additional benefits include, without limitation: increased revenues to the County and other agencies that receive property tax revenues from the project site; payment of certain development fees to various agencies; development of additional housing units and recreational amenities; contributions by the applicant for affordable housing and to the Homeless Trust Fund; needed safety improvements to the existing circulation system; and a means to acquire additional revenue to upgrade the existing levee. The No Project Alternative would not be considered a long- term alternative: because it is inconsistent with the intent of County General Plan Policies for the area and the Urban Limit Line policy, which envision development in this area. Findings: iThe Planning Commission rejects the No Project Alternative because the benefits of the project as discussed above, are more productive in the long-term than the No Project Alternative; and ,further, because the County General Plan and Urban Limit Line policy envision development of the project site. B. THE RANCHETTE ALTERNATIVE Facts: The Draft EIR sets forth the discussion of the Ranchette Alternative at pages 4-5 through 4-7 . The Ranchette Alternative would result in development of the project site at a density of one dwelling unit per 5 acres for a total of 136 -57- dwelling units. The resulting land use would be small ranchettes. No recreational amenities would be required because the Off-Island Bonus Area designation would not apply for development at this density. The Ranchette Alternative creates fewer impacts than the proposed project. These impacts are summarized below. 1. The land use pattern under this Alternative would be more rural as a result of. larger parcels. 2. This Alternative would reduce the number of vehicle trips generated from the project by approximately 85%. 3 . This Alternative would reduce the air quality impacts by roughly 90% when compared to the project. 4 . Fewer impacts would occur on vegetation and wildlife due to the lower density- and resulting population. 5. Since the internal levee system would not be constructed and homes would be on larger lots, the visual character of the area would be similar to what currently exists. 6. This Alternative would decrease noise levels as .a result of less traffic, new recreational uses . and population. 7. This Alternative would have less :of a .demand on,. public services and utilities. Some public facilities (i.e. , fire, police and schools) may need to be upgraded to serve development under this Alternative. The Ranchette Alternative . would create the , following significant impacts that would not be associated with the project. These also identify some of the benefits of the project. 1. Piecemeal development of the area which would create a greater conflict between residential and agricultural uses than the project. In addition, this7Alternative would not provide the additional needed housing for the county as does the project. 2 . This Alternative would have a greater impact on wetlands since development would occur in smaller pieces which would be more difficult to regulate than the project. 3 . Since this Alternative would not propose an internal levee system as does the project, the housing units would be built on stilts which would cause an aesthetic impact. In addition, stilt development in new subdivisions is inconsistent with -the General Plan. -58- 4 . Development at this density would not provide a sufficient tax base to upgrade the existing levee. 5. Development under this Alternative would not include significant drainage improvements because each parcel would be developed separately. This could result in greater impacts on local drainage facilities. 6. This Alternative could result in adverse impacts to cultural resources as a result of piecemeal development of the site. Under this Alternative, it would be more difficult to require preservation and avoidance due to segmented development that would occur. 7. This Alternative will accelerate projected growth in other areas of the eastern part of the County by providing only limited opportunities for housing on the site. Those areas may contain more serious environmental constraints (i. e. , prime soils and significant wetlands) than the project that would be damaged in an effort to provide the housing. As further explained in Section VII of these Findings, the eastern part of the County is projected to have the highest rate of population growth during the next two decades. This Alternative would reduce or avoid some of the impacts of the project. However, as identified in these Findings, .most of the impacts of the project can be mitigated to less-than-significant levels. This Alternative would not provide certain benefits which would be provided by the project, such as those mentioned above. Additional benefits include without limitation: increased property tax revenues to the County and other agencies; payment of certain development fees to various agencies; a means to acquire revenue to upgrade the existing levee; development of additional housing units and recreational amenities; needed safety improvements to the existing circulation system; and significant contributions toward affordable housing and to the Homeless Trust Fund. Findings: The Planning Commission rejects the Ranchette Alternative because the benefits of the project as discussed above are more beneficial in the long-term than the Ranchette Alternative. C. RANCHETTE ALTERNATIVE WITH CLUSTERING Facts: The Final EIR sets forth the discussion of the Ranchette Alternative with Clustering at pages 4-131 through 4-134 . This Alternative is identical to the Ranchette Alternative, but this Alternative would cluster the 136 units on one portion of the site. Cattle grazing would still occur on the remaining portion of the site. -59- This Alternative creates fewer impacts than on the project such as the following: 1. The majority of the project's site would be preserved in its present agricultural state because all the homes would be clustered on one portion of the site. This land use pattern would be more similar to the existing pattern. 2. This Alternative would reduce the number of vehicle trips generated from the project by approximately 85% when compared to the proposed project. 3. This Alternative would reduce the air quality impacts by roughly 90% when compared to the project. This alternative would also reduce emissions. of ozone precursors and potentially avoid exceeding the BAAQMD's threshold for these emissions. Construction generated dust emissions would also be substantially reduced as a result of less soil disruption. 4 . This Alternative would reduce impacts on vegetation and wildlife. By clustering the 136 units on one portion of the site, the rest of the site would remain in its existing state. This Alternative would displace the vegetation and wildlife associated with the portion of the site developed with the 136 units. 5. Visual impacts would be reduced because the majority of the site would remain in its agricultural/open state. The area where the units are clustered would provide a visual impact similar to that of the project. . 6. Noise levels would decrease as a result of less traffic, less people and no recreational uses. Construction noise would also be substantially reduced with this Alternative. 7 . This Alternative would reduce the demands on local public services and utilities as a result of fewer people living on the site. This Alternative would create the following potential significant impacts that would not be associated with the project. These also identify some of the benefits of the project. 1. This Alternative would provide significantly fewer housing units than the project and no recreational/ amenities. The provision of additional housing and recreational amenities in the Bethel Island area is a goal of the County and has been planned for in its General Plan. -60- 2 . This Alternative would not be able to finance some of the needed roadway improvements in the area. 3. This A:iternative would not provide an internal levee system :nor would it be large enough to fund improvements of theexisting RD-799 levee. 4. Under this Alternative, new housing would be constructed on stilts which would create an aesthetic impact. Stilt structures in new subdivisions is inconsistent with the General Plan. 5. It is not expected that this Alternative would be able to provide the necessary level of financing to improve various public services (i.e. , fire, police and schools) , which would be needed. 6. A non-ground water source may not be developed under this Alternative. Development of a non-ground water source is a significant benefit of the project. 7 . This Alternative will accelerate projected growth in other areas of the eastern part of the County by providing only limited opportunities for housing on the site. Those areas may contain more serious environmental constraints (i.e. , prime soils and significant wetlands) than the project that would be damaged in an effort to pr'ovide the housing. As further explained in Section VII of these Findings, the eastern part of the County is projected to have the highest rate of population growth during the next two decades. This Alternative would reduce or avoid some of the impacts of the project. However, as identified in these Findings, most of the impacts of the project can be mitigated to less than significant levels. This Alternative would not provide certain benefits which would be provided by the project such as those mentioned above. Additional benefits include without limitation: increase property tax revenues to the County and other agencies; payment of certain development fees to various agencies; development of additional housing units and recreational amenities; a means to acquire revenue to upgrade the existing levee; needed safety improvements to the existing circulation system; and a significant contribution toward affordable housing and the Homeless Trust Fund. Findings: The Planning Commission rejects the Ranchette Alternative with Clustering because the benefits of the project as discussed above are more beneficial in the long-term than this . Alternative. -61- D.. LOW DENSITY ALTERNATIVE Facts: The Draft EIR sets forth the discussion of the Low Density Alternative at pages 4-8 through 4-10. This Alternative would involve the development of approximately 510 dwelling units on the project site at a density of one unit per net acre. This Alternative takes advantage of the low end of the Off-Island Bonus Areas recreational criteria. This Alternative would include recreational amenities similar to those of the project. The Low Density Alternative creates fewer potential impacts than the proposed project. These impacts are summarized below. 1. The intensity of the uses on the site would be reduced to some degree. This Alternative would result in fewer housing units being developed. A reduction in the number of housing units would increase the amount of open space/park land that could be provided on-site. 2 . This Alternative would reduce the number of vehicle trips by about 40%. 3 . This Alternative would reduce potential air quality impacts associated with the project by approximately 53% However; this Alternative may still result in exceedance of the BAAQMD's threshold for emission of those ozone precursors. 4 . This Alternative may result in fewer impacts in vegetation and wildlife. Due to lower density, more area would be allowed for open space. 5. Visual impacts under this Alternative would be reduced because of the lower density and additional open space that would be provided. 6. This Alternative would result in reduced demand on public services and utilities because of the reduction in the number of units and project population. The Low Density Alternative would create the following potential significant impacts that would not be associated with the project. These also identify some of the benefits of the project. 1. This Alternative would result in fewer housing units being developed and therefore, would not provide the level of housing opportunities for the area. 2 . Homes may be constructed on stilts (unless the project site is removed from the flood plain) which would cause an aesthetic impact. New subdivisions constructed on stilts is inconsistent with the General Plan. -62- 3 . Development at this density would not be able to fund construction of a levee system to remove the site from the flood plain. The General Plan precludes substantial development until the area is removed from the flood plain. . 4 . Development at this density would not provide a sufficient tax base to upgrade the existing levee. 5. A non-ground water source may not be financially feasible with the Alternative. The development of a non-ground water source is a significant benefit of the proposed project. 6. This Alternative will accelerate projected growth in other areas of the eastern part of the County by providing only limited opportunities for housing on the site. Those areas may contain more serious environmental constraints (i.e. , prime soils and significant wetlands) than the project that would be damaged in an effort to provide the housing. As further explained in Section VII of these Findings, the eastern part ' of the County is projected to have the highest rate of population growth during the next two decades. This Alternative would reduce or avoid some of the impacts of the project. However, as identified in these Findings, most of the impacts of the project can be mitigated to a less than significant level. This Alternative would not provide certain benefits that would be associated with the proposed project as discussed above. Additional benefits include, without limitation: . increased property tax revenues to the County and other agencies which collect property taxes from the project site; additional development fees which would be assessed on the project; a means to acquire revenue to upgrade the existing levee; additional housing units ' with recreational amenities; needed safety improvements to the existing circulation system; and significant contributions toward affordable housing and the Homeless Trust Fund. Findings: The Planning Commission rejects the Low Density Alternative because the benefits of the project as discussed above are more beneficial in the long-term than the Low Density Alternative. .. E. MAXIMUM DENSITY ALTERNATIVE Facts: The Draft EIR sets forth the discussion of the Maximum Density Alternative at pages 4-11 through 4-12 of the EIR. This Alternative would . represent the maximum level of development possible on the project site under the current land use designation of Off-Island Bonus Area. Under this Alternative, a density of 2 .9 -63- dwelling units per net acre would be allowed for a total of 1, 530 dwelling units. This Alternative would include recreational amenities such as a golf course, lake, marina or other significant recreational amenity. This Alternative would also include the construction of an interior levee. The Maximum- Density Alternative would create greater impacts than the project. These impacts are summarized below. 1. This Alternative would result in a higher overall project than the project which may result in less area designated for recreational and open space uses. 2. This Alternative would generate approximately 20% higher traffic volumes than the project. 3 . The air quality impacts of this . Alternative would be approximately 13% higher than those associated with the project. This Alternative would result in a greater exceedance of the BAAQMD's threshold for emission of ozone precursors than would be associated with the project. 4 . The high overall density of this Alternative may result in reduced area dedicated for wetland mitigation, and wildlife enhancement. 5. This Alternative would create a higher demand on public services and utilities. This Alternative would not reduce or avoid some of the impacts associated with the project. Rather, this Alternative would intensify some of those impacts. More housing units would be provided under this Alternative which would assist the County in achieving needed housing in the area. However, the more intense use will result in. great impacts than the project. Findings: For the reasons set forth above, the Planning Commission rejects the Maximum Density Alternative. F. OFF-SITE ALTERATIVE Facts: The Draft EIR sets forth a discussion of the Off-Site Alternative at pages 4-13 through 4-15. This Alternative is located along the north side of Cypress Road and west Jersey Island Road adjacent to the Off-Island Bonus Area. This site is approximately the same size as the project site. This Alternative would include development of the same number of units as a project (1, 330) along with the same recreational amenities. The Off-Site Alternative site is designated M-8 (Mixed Use- Oakley Community Center) in the County General Plan. The M-8 designation includes three properties totalling 1, 539 acres. The -64- eastern most parcel makes up this Alternative site. The purpose of the M-8 designation is to provide for the integrated development of these three properties through a comprehensive planning process. The focal point of development on this site is to a community center complex 'including a large community pool for the Oakley area. This designation allows for open space areas, wetland preservation, commercial/office development and single and multi- family residential development. Locating the project at this site would have the same basic impacts as the project in its proposed location. This alternative site may result in less construction dust nuisance because of the reduced number of adjacent residences. Due to multiple ownership of the alternative site, it would be more difficult to construct an integrated development in a timely manner. Moreover, the project does not include some of the amenities intended by the M-8 designation such as a community center complex, commercial/office use and multi-family development. Development on this alternative site will not achieve the goals of the County General Plan to provide additional housing and recreational amenities in the Bethel Island Area. Findings: The Planning Commission rejects the Off-Site Alternative for the reasons stated above. G. COMMERCIAL ALTERNATIVE Facts: The Draft EIR sets forth the discussion of the Commercial Alternative at pages 4-16 through 4-17 . This Alternative would include the same level of residential development as the project ' (1, 330 dwelling units) as well as the same recreational amenities. However, this Alternative would include neighborhood commercial development near the project entrance at Cypress Road and Bethel Island Road. This Alternative was evaluated to address the jobs/housing imbalance in the East. County area. The Commercial Alternative has the following potential significant impacts that are not created by the project. These also identify some of the benefits of the project. 1. The. County General Plan designation for the project site does not include commercial uses. An amendment to the General Plan would be required to allowcommercial development. 2 . The local and regional air quality impacts of this Alternative would be approximately 15.% greater than the project. -65- 3 . Other local commercial providers are likely to object to the commercial uses. Some of the commercial uses proposed under this Alternative would be the same as those already offered in the area. 4 . The commercial uses would generate additional noise resulting from truck deliveries and mechanical equipment. Additional commercial development would provide additional jobs and thereby, improve the jobs/housing balance in East County. The amount of employment uses - that would be generated from this Alternative would fall short of providing a beneficial impact on the existing jobs/housing imbalance. The Board of Supervisors in 1991 in its General Plan created the new land use designations for the Bethel Island Area. In . doing so, they centralized the commercial uses along the Bethel Island Bridge where they presently exist. Commercial uses as proposed by .this Alternative would run counter to the Boards original intent as demonstrated under the General Plan. Findings: The Planning Commission rejects the Commercial Alternative for the reasons stated above. IV. SIGNIFICANT UNAVOIDABLE IMPACTS The Draft EIR discusses the projects significant unavoidable impacts at page 5-1. CEQA requires that significant unavoidable impacts of the project be described. (Guidelines § 15126 (b) . ) The project would result in the following unavoidable significant impacts: 1. Air Ouality. The project would exceed Bay Area Air Quality Management District (BAAQMD) significant thresholds for emissions of ozone. precursors, NOX and ROG. This impact is more thoroughly discussed under the Air Quality Section in the EIR and these Findings. Mitigation measures are proposed to mitigate this impact however, with implementation of the measures-the impact would remain significant and unavoidable. 2. Visual Quality. The project will significantly change the existing visual character of the site. The visual character of the site will change from generally vacant, flat pasture land to residential/recreational uses. The project site will also include an internal levee. This impact is more thoroughly discussed in the Visual Quality Section in the Draft EIR and these Findings. Mitigation measures are proposed to mitigate this impact however, even with the implementation of the measures the impact would remain significant and unavoidable. -66- 3. Jobs/Housing Balance. The project would result in an unavoidable impact on East County's jobs/housing balance. The area is currently experiencing an imbalance. This impact is more thoroughly discussed in the Land Use section of the Draft EIR and these Findings. A mitigation measure has been proposed to reduce this impact however, even with its implementation, the impact would remain significant and unavoidable. 4. Construction Noise. Construction of the project roject would result in elevated noise levels. These impacts will only be short term. This impact is more thoroughly discussed in the. Noise Section of the Draft EIR and these Findings. Mitigation measures are proposed to reduce construction noise impacts. However, even with implementation of the mitigation measures, construction noise impacts will remain short term, significant and unavoidable. The Draft EIR identified construction period dust as a significant and unavoidable impact. In response to the comments on the Draft EIR, two additional mitigation measures (Mitigation Measures 3 . 3-3 and 3 . 3-4) were recommended and adopted in these Findings. These two new measures in conjunction with the other measures in the Draft EIR and adopted herein, mitigate this impact to a level of insignificance. As a result, this impact is no longer significant and unavoidable. Findings: The Planning Commission finds that the project will have significant: and unavoidable impacts on air quality, visual quality, the jobs/housing imbalance and noise resulting from construction. The Planning Commission further finds that the measures set f6rth in these -"Findings to mitigate impacts on construction period dust' will 'mitigate the impact to a level of insignificance. As a result of these significant and unavoidable impacts, the Planning Commission hereby adopts a Statement of Overriding Considerations and finds therein that the benefits of the project outweigh these significant and unavoidable impacts. (See Section IX..) V. CUMULATIVE IMPACTS Facts: The Draft EIR contains a discussion of the project's potential cumulative impacts at pages 5-2 through 5-7. A list of past, present and reasonably foreseeable future projects and a summary of projections for areas adjacent to the project site are contained at pages 5-2 through 5-4 of the Draft EIR. Set forth below is a brief discussion of the potential cumulative impacts of the project. The cumulative impact analysis contained in the EIR is based on the specific analysis conducted under each individual topic section, information contained in the County General Plan and its EIR. -67- 1. Land Use. The project in connection with other projects in the area will result in a change in the existing . land uses. This change is primarily from agricultural/open space uses to urban uses. This change has been planned in the County General Plan and through the establishment of the Urban Limit. Line which identifies those areas to be developed with urban uses. The EIR on the County General Plan discusses the impacts from changes in the land use patterns at pages 4 . 1-1 through 4 . 2-35. The County General Plan requires that urban development in the County be limited to no more than 35% of the land in the County. At least 650 of all land must be preserved for agricultural, open space, wetlands, parks and other non urban uses. The project, in addition to other projects in the Bethel Island Area, will mitigate its impact on the incremental loss of converting agricultural/open space to urban uses by paying a Protection Fee. This Fee shall be paid for each residential unit to acquire development rights on agricultural land (and open space or wetland areas) or to provide financing for farmers to continue agricultural production. The project will additionally impact the already existing East County's jobs/housing imbalance. This project, in addition to other projects in the Bethel Island Area where limited commercial development is permitted, will contribute to the imbalance of the jobs/housing. This impact is expected to be short-term until other developments are approved that include employment-generated uses. The project will not create a significant cumulative impact by converting the site to urban uses. However, it will contribute to the cumulative impact on the jobs/housing imbalance. 2. Traffic. The cumulative impacts on traffic are specifically addressed in the Draft EIR at pages 3-38 through 3-63.. The project will fully mitigate its cumulative impact by contributing to the construction of the Delta Expressway, the Byron Road extension, State Highway 4/Cypress Road intersection, State Highway 4/Neroly Road intersection, Cypress Road/Laurel Road connection from State Highway 4 to Machado Lane, and the widening of Cypress Road between State Highway 4 and Machado Lane. The project will further mitigate the impact through its plans and the implementation of the adopted traffic Mitigation Measures in these Findings. With the construction and/or contribution of regional roadway improvements, compliance with the traffic mitigation measures and conditions of approval, and implementation of its plan, the project will not have a significant cumulative impact on traffic. 3. Air quality. The project in combination with other projects would add to emissions in the Bay Area Basin. Future projects would be subject to the County's TDM requirements which -68- i would help reduce the total number.. of automobile trips in the County. Future projects are also expected to provide transit stops and other modes of transportation (i.e. , pedestrian and bicycle trails) in an effort to reduce automobile trips. The project will mitigate its air .quality impacts to the extent feasible. However, these measures will not mitigate the impacts to a less than significant level. The project. will result in .a cumulative impact on regional emissions with respect to NOX and ROG. 4. Vegetation and Wildlife. The project in connection with other development will result in the loss of vegetation and wildlife habitat. The County General Plan contains policies regarding the protection, preservation and conservation of wetlands and other biologically important areas. In addition, the County is currently preparing a wetland ordinance to protect wetland areas. This ordinance will require avoidance, minimization and/or compensatory mitigation techniques to be employed with respect to projects having a potential effect on wetland and related areas. 'To the extent permitted, the County will require 3 : 1 compensatory mitigation of any project affecting significant wetland areas. In addition to these policies, the County has, through the passage of Measure C, established an Urban Limit Line which delineates areas where urban development may occur. Again, the intent of the Urban Limit Line and Measure C is to limit urban development within the County to 35% of 'the land area. The remaining area (65%) is to be left in its current rural, agricultural, open space state. Projects in the Bethel Island Area are also required by the General Plan to pay the Protection Fee which will be used to acquire development rights on wetland and open space areas. Priority for the acquisiton of open space and wetland areas will be given to the on-island area. The project plans include extensive measures to mitigate its impacts on vegetation and wildlife. The project plans in addition to the measures adopted in these Findings will mitigate to a level of insignificance the projects cumulative impacts on vegetation and wildlife. S. Visual Quality. The project in connection with others in the area would contribute significantly to the change in visual character from , primarily agricultural to a mix of suburban residential and agricultural uses. The project plans include extensive measures to mitigate its impact on visual quality. The project plans in'addition to the mitigation measures adopted herein will not mitigate this impact to a level of insignificance. As a result, the project will contribute to the cumulative impact on , visual quality. -69- 6. Noise. Noise impacts of this project have been extensively addressed in the specific Noise Section of the EIR and these Findings. The project plans and mitigation measures will mitigate noise impacts, other than those due to construction, to a level of insignificance. All projects in the area will not be constructed at the same time. Thus, the project will not contribute to the cumulative impact on noise resulting from construction. Cumulative noise impacts will be addressed through environmental review of future projects and require conformity with County noise standards. The project will not contribute to the cumulative impact on noise. 7. Hydrology and Drainage. The project in connection with other development in the area will result in changes to regional hydrology and drainage patterns. This change will be addressed through environmental review of future projects. These improve- ments will be required to conform with County policy and growth management requirements. Hydrological and drainage impacts can generally be mitigated through proper engineering techniques and the use of drainage facilities. The project has mitigated its impacts to a level of insignificance and will not contribute to the cumulative impacts on hydrology and drainage. 8. Geology, Soils and Seismicity. The project in connection with other developments in the area would result in exposure of additional persons and structures to potential hazards from liquefaction and seismic shaking. This potential cumulative impact will be addressed through requirements that detail geotechnical plans and measures to satisfactorily address .1iquefaction .problems be developed prior to project approval and through the requirement that all structures be constructed to withstand seismic shaking. The project will not result in significant cumulative impacts on geology, soils and seismicity. 9. Public Services. The project in connection with other development in the area will result in additional demands on public services, such as police, fire and schools. This cumulative impact is addressed by compliance with County growth management standards and other County policies which require future development to pay its fair share toward impacts on community services. Therefore, cumulative impacts on public services will not be significant. 10. Water. The project in connection with other planned development will not result in cumulative impacts on water. The Oakley Water District which is intended to .serve the project site has prepared a Water Management Master Plan which addresses the District's ability to serve development within its Sphere of Influence. New facilities are being constructed to serve projected -70- growth but not to induce growth. As a requirement of Measure C and the growth management policies, future development is required to demonstrate adequate available capacity prior to project approval. The project, will mitigate to a level of insignificance its impacts on water and will not contribute to the cumulative impact on water. 11. sewage ' Disposal. The Ironhouse Sanitary District has adequate capacity to serve the project and some additional development in the area. New facilities are being constructed to serve projected growth but not to induce growth. As a requirement Measure C and :the growth management policies, future development is required to demonstrate adequate available capacity prior to project approval. The project adequately mitigates its impacts on sewage disposal and will not contribute to a cumulative impact on sewage. 12 . Other Utilities . The project will not have an impact on electrical, gas and telephone utilities or on solid waste as discussed at pages 3-207 through 3-214 of the Draft EIR. With respect to solid waste, the County has recently approved new solid waste sites which are more than adequate to serve the project and surrounding development. 13. Human Health. The Delta area has historically experienced mosquito problems. This potential impact is addressed by CCMAD which: is responsible for mosquito abatement and management. Future projects in the area will be required to conform with CCMAD requirements. Implementation of standard maintenance practices and proper design of drainage facilities will mitigate cumulative impacts to a less than significant level. 14. Cultural Resources. Potential impacts on cultural resources will be addressed through the environmental review process of each specific project and requirements for cultural resource studies in areas known to contain cultural resources. The environmental review process would be used to identify areas most sensitive to development and provide for the avoidance or limitation of development in these areas. The proposed project will avoid areas containing significant cultural resources or provide uses appropriate for areas that are sensitive. As a result, the project will not contribute to the cumulative impact on cultural resources. Findings: ' Based on the EIR and the entire record, the Planning Commission finds that the project's cumulative impacts have been mitigated to a level of insignificance other than the impacts on East County's jobs/housing imbalance, air quality and visual quality. . In recognition thereof, the Planning Commission hereby adopts the Statement of Overriding Considerations and finds -71- therein that the projects benefits outweigh the remaining significant unavoidable impact. (See Section IX. ) VI. SIGNIFICANT IRREVERSIBLE CHANGES Facts: The EIR discusses significant irreversible changes at page 5-8 of the Draft EIR. CEQA requires (1) an analysis of the justification of non-renewable resources during the initial and continual phases of a project which may be irreversible since large commitments of such resources makes removal or non-use thereafter unlikely; and (2) an analysis which describes irreversible damage which could result from environmental accidents with a project. Guidelines §15126 (f) . The EIR discusses three potentially significant irreversible changes associated with. development in the project area; 1. The commitment of energy and raw materials for development would deplete certain non-renewable resources. 2 . Irreversible foreclosure of the agricultural uses (cattle grazing) on the site. 3 . Permanent changes to the existing hydrology by removing approximately 685 acres from the flood plain through the construction of an internal levee. The construction of the project will utilize energy and raw materials. The amount of energy and materials that will be used is so minimal when compared to the quantities available for use. This is not a significant irreversible change. The EIR confirms that the conversion of the site from open space/agricultural land to urban uses is not a significant impact. (See Draft EIR Section at Land Use, Planning and Public Policy pages 3-1 through 3-27 and Final EIR at 4-7 through 4-21 and 4-42 through 4-44 . ) Development of this area has been planned by the County for some time. The County General Plan includes the site within its Urban Limit Line and designates the area for the development of 1-0-2 .9 dwelling units per acre. Moreover, the project site does not contain "prime" agricultural land; the lands are of marginal agricultural productivity. However, in order to minimize the incremental loss of such lands, the developer will be required to pay a Protection Fee to acquire development rights on agricultural land or to provide financing for farmers to continue agricultural production. The flood plain area is approximately 3 , 000 acres. Approximately 685 acres of this area will be removed with the -72- construction of an internal levee. In the highly unlikely event a breach occurs on the existing levee that creates major flooding, the floodwaters : will have less area to flow. It is purely speculative that there would ever be a breach and resulting flooding of such an extreme magnitude, that the presence of the internal levee would create a safety hazard for residents and structures in the; flood plain. To the contrary, the internal levee provides a safe refuge in the event of a flood. There are no irreversible damages which would result from environmental accidents with the project. The project does not propose any use that would cause environmental accidents. Findings: The Planning Commission finds that certain existing conditions will be irreversibly changed as a result of the project. These changes would not occur if new development was not permitted which would contradict the General . Plan policies for this area namely, to provide new residential development in a recreational setting. VII. GROWTH INDUCING IMPACTS Facts: The Draft EIR discusses the project,'s .growth inducing impacts at pages '5-9 and 5-10. The Final EIR also discusses growth inducing impacts: at pages 4-44 and 4-45. Pursuant to CEQA, a project is considered growth inducing if it could prematurely foster economic . growth or population growth. Guidelines § 15126 (g) . The EIR identifies the following actions from the project that could be considered growth inducing: 1. Annexations to the Oakley Water, Contra Costa Water District and Ironhouse Sanitary District. 2 . Installation of roadway improvements. 3 . Increase in population in the area could create pressures for conversion of agricultural and open spaced designated lands to residential uses. Growth in and around the Bethel Island Area is expected to occur sooner rather than later. The project is the first major project proposed. in the area. However, the County has received other applications for development in the area. The properties in and around the project area are within the Urban Limit Line and are designated in the County General Plan for residential/commercial/ recreational uses. The extension of new services does not create a growth- inducing effect' if the services are planned to accommodate -73- development levels in the Bethel Island Area and not all surrounding areas. The new sewer and water facilities will be designed so as not to encourage growth in areas outside of the Bethel Island Area. In terms of growth-inducing impacts on surrounding areas, rural East Contra Costa County, . including Antioch, Brentwood and the Oakley area, are projected to have the County's highest rate of population growth during the next two decades. (Contra Costa County General Plan at pages 6-20 through 6-26 and Association of Bay Area Governments (ABAG) projections for 1991, incorporated herein. ) Most of this projected growth would take place in the surrounding areas and is likely to occur regardless of future development patterns or rates of growth in the project area. Findings: For the reasons stated above, the Planning Commission finds that the project will not create ..significant growth-inducing impacts. VIII. RELATIONSHIP BETWEEN SHORT-TERM USE AND LONG-TERM PRODUCTIVITY Facts: The Draft EIR at page 5-11 discusses the relationship between local the environment -and the maintenance and enhancement of long-term productivity. Thee -EIR confirms that potential short- term impacts of the project would primarily result from construction (i.e. , visual disruption, dust emissions and energy . consumption) . The project plans and mitigation measures adopted herein will assist in reducing construction impacts. Long-term potential impacts include reduction in agricultural uses within the area, changes to the existing vegetation and wildlife on site, increased population and its resulting impacts on traffic congestion on local roadways, noise and air quality. As set forth herein, the project's extensive plans and mitigation measures reduce these long-term impacts to a level of insignificance other than air quality. Moreover, the project, through its mitigation, creates a more beneficial situation than exists without the project. One example is the projects creation of additional wetlands. These new wetland areas will provide wetlands with higher biological values than presently exist. The' project will create other beneficial long-term effects such as an addition of 1, 330 units to the County's needed housing stock, contribution to affordable housing in the amount of $4 ,432,89. . or the construction thereof, contribution to needed roadway improvements, and contributions to the upgrading of the existing RD-799 levee. Other beneficial impacts are discussed throughout these Findings and . in other parts of the record. -74- Findincgs: The Planning Commission finds that on balance (with regard to the project relationship between local short-term use and the maintenance and enhancement of long-term productivity) , the long-term benefits of the project outweigh any short-term and long- term effects. IX. STATEMENT OF OVERRIDING CONSIDERATIONS Following a " determination that significant impacts remain following the adoption of mitigation measures, approval of a project must be accompanied by a Statement of Overriding Considerations. � CEQA requires the benefits of a project to be balanced against its unavoidable environmental impacts in determining whether to approve the project. (Guidelines § 15093. ) The EIR discussed over 40 potential direct significant environmental impacts, in addition to cumulative impacts, that could result from the project. Only 4 out of the 40 potential impacts result in unmitigated or unavoidable impacts. These unavoidable impacts include: a short-term impact on the current jobs/housing imbalance, an increase in ROG and NOX pollutants from vehicle traffic, a change in the visual character of the site from generally undeveloped area to urban uses, and .short-term noise impacts resulting from construction activities. The Planning Commission has determined that the benefits of this project outweigh these four unavoidable environmental impacts. In making this determination, the following factors and public benefits were considered and comprise the Statement of Overriding Considerations. A. Need For Additional Housing. The County General Plan, Housing Element, sets forth projected housing needs County-wide -for the years 1988 to 1995. (General Plan at pages 6-1, et sea. ) The General Plan cites information provided by the Association of Bay Area Governments (ABAG) in its January 1989 publication, Housing Needs Determinations (incorporated herein by reference) . State law requires ABAG to determine housing needs for all income levels so that each juris- diction can provide its "fair share" of housing for each income group. ABAG sets forth projected housing needs in Contra Costa County in four separate income categories: Very Low; Low; Moderate; and Above Moderate. The ABAG figures estimate . a total projected need for 48,756 units in the County for the years 1988 to 1995; 42 , 309 units in incorporated areas and 6, 447 in unincorporated areas. (General Plan at page 6-22 , Table 6-6. ) Of such 48 ,756 units, 23 , 198 units are projected to be required in the "Above Moderate" category. (General Plan at page 6-24 , Table 6-8. ) Specifically, the unincorporated areas, which include the project. site, is projected to require 2 , 966 "Above Moderate" income units. -75- The purchase price for an "Above Moderate" unit is above $132, 000. 00. (General Plan at page 6-25, Table 6-10. ) The project is proposing 1, 330 units within the range of $175, 000 - $400, 000 per unit. Several County General Plan goals, policies and implementation measures support and encourage approval of "Above Moderate" housing in the project area. The General Plan, Housing Element, at page 6-106, Goal 6-B, sets forth the goal of making "available a wide range of housing types and residential densities to meet the needs of all age groups and household sizes within Contra Costa County's population. " The Housing Element, at page 6-107, Policy 6-1, states that a "balance of housing types, tenures, densities, and price ranges shall be encouraged, supported, and stimulated. " Policy 6-6, at page 6-107 , confirms that "[h]ousing opportunities shall be provided for all economic segments of the population throughout the County. " The Planning Commission specifically finds that there is a need for "Above Moderate" housing in the Bethel Island Area, which is addressed by the project. B. Contribution to Affordable Housing and Homeless Trust Fund. The project will contribute fees for affordable housing of $3, 333 per dwelling unit. Based on 1, 330 units, this amounts to $4, 432, 890. Affordable housing includes housing in four separate income categories: Very Low; Low; Moderate and Above Moderate. The purchase price for a unit in the category of Very Low is less than $55, 000; in Low it is $55, 000 to $88, 000; in Moderate it is $88, 000 to $132, 000; and Above Moderate it is above $132, 000. (General Plan at page 6-25, Table 6-10. ) The ABAG figures estimate a total projected need for 48 , 756 "affordable" units in the County for the years 1988 to 1995; 6, 447 units in unincorporated areas. (General Plan at page 6-22 , Table 6-6. ) Several County General Plan goals, policies and implementation measures support and encourage approval of affordable housing. The General Plan, Housing Element, at page 6-106, Goal 6-A:,. sets forth the goal of making ". . .decent, safe and affordable housing available. to all Contra Costa County residents. " The Housing Element at page 6-107 , Policy 6-3, states that 11 [a]ppropriate financial and non-financial assistance shall be committed to reducing the cost of development for very low- and low-income housing. Such assistance shall also be considered for moderate- income housing. " The project applicant will also make a monetary contribution . to the Homeless Trust Fund. The Board of Supervisors, in making its decision on the rezoning and preliminary and final development plans, will determine the exact amount of this contribution. -76- The County General Plan, Housing Element, sets forth the projected needs for the homeless population. (General Plan at pages 6-46 through 6-65. ) The General Plan recognizes that " [h]omelessness has become increasingly visible in Contra Costa County and is expected to increase. " (General Plan at page 6-46. ) In an effort to alleviate homelessness, a Homeless Trust Fund was established. Funds from this fund have been utilized to: in addition to other homeless programs, increase the capacity of existing shelters as well as developing new shelter facilities. (General Plan at page 6-61. ) The project's contribution to the Homeless Trust Fund will allow the County to continue fulfilling its purposes in establishing the Homeless Trust Fund. The Planning Commission finds that there is a need for the provision of affordable housing and housing for the homeless. The Planning Commission finds that this project will assist the County in achieving these goals. C. Project Will Provide Funding for the Existing Levee. The existing RD-799 levee system does not meet the standards of the Federal Emergency Management Agency (FEMA) in regard to the Short-Term Hazard Mitigation Plan Levee (HMP) or the Urban Standard Levee. In order for existing development to maintain eligibility for federal funds for a declared disaster, the RD-799 levee must comply with HMP design standard level. Addition- ally, in order to comply with the Federal Flood Insurance Program and County policy, all new development within the existing flood plain must be protected by an Urban Standard Levee or have the habitable floor of all structures at 10 feet, or greater, above mean sea level. For purposes of the Federal Flood Insurance Program, FEMA will only recognize those levee systems that meet, and continue to meet, minimum design, operation and maintenance standards that are consistent with the level of protection required. The existing levee does not meet these standards. (Draft EIR at pages 3-122 and 3-123 . ) An estimated cost of $20, 000, 000 would be , required. to bring the existing levee to the FEMA Urban Standard Levee level of protection. In the 1991-1992 fiscal year, the RD-799 had an operating budget of $156, 000. Due to recent federal. and state budget cuts, matching funds for levee upgrading and maintenance are difficult to obtain. (Draft EIR at pages 3-122 through 3-124 . ) The project will construct an internal levee. This levee must be accepted by a governmental agency. The project applicant has requested acceptance by RD-799. (Final EIR, Appendix C. ) If RD-799 accepts responsibility, the project site will remain in the District. As such, the District can assess each new homeowner for maintenance of the existing levee and internal levee. This new tax base will allow the District long-term funding to maintain and upgrade the existing levee. Without the project, it would not be -77- MITIGATION MONITORING AND REPORTING PROGRAM FOR THE CYPRESS LAKES AND COUNTRY CLUB PROJECT APRIL 1993 PREPARED FOR: CONTRA COSTA COUNTY ADOPTED: APRIL 5, 1993 BY: EAST COUNTY REGIONAL PLANNING COMMISSION EXHIBIT .,may TABLE OF CONTENTS I. INTRODUCTION 1 Purpose of the Report 1 Project Description I Monitoring and Reporting Overview 2 How to Use this Report 3 II. MONITORING AND REPORTING REQUIREMENTS FOR MITIGATION MEASURES IN THE DRAFT EIR FOR THE CYPRESS LAKES AND COUNTRY CLUB PROJECT 4 III. MITIGATION MEASURE MONITORING AND REPORTING COMPLIANCE FORM 55 IV. MASTER MITIGATION COMPLIANCE CHECKLIST 56 I. INTRODUCTION Purpose of the Report The following Mitigation Monitoring Report has been prepared for the Cypress Lakes and Country Club Project in accordance with the California Environmental Quality Act (CEQA) and Assembly Bill 3180 (AB 3180). AB 3180 requires public agencies to report on or monitor mitigation measures adopted under the CEQA process to ensure compliance during project implementation. The provisions of AB 3180 are triggered when a public agency 1) adopts a mitigated negative declaration,or 2) completes an Environmental Impact Report (EIR) and makes findings pursuant to subdivision (a) of the Public Resources Code section 21081 which states that, "changes or alterations have been required in, or incorporated into the project for which an EIR has been completed which mitigate or avoid the significant environmental effects thereof as identified in the completed environmental impact report." AB 3180 leaves the task of designing a reporting or monitoring program to individual public agencies. Under AB 3180, public agencies are given broad latitude in developing programs to meet the variety of projects and circumstances affecting their jurisdiction. This Monitoring and Reporting program has been specifically designed for the Cypress Lakes and Country Club Project. It is based on the mitigation measures adopted for the project as specified in the Draft EIR, dated December 1992 and the Final EIR, dated March 1993. This report has been prepared for Contra Costa County, the Lead Agency responsible for the preparation of the Draft EIR, Final EIR, and Findings for the project. However, many of the mitigation measures are the responsibility of the project applicant. Project Description The Cypress Lakes and Country Club project site is located in the Sacramento-San Joaquin Delta area of unincorporated north-eastern Contra Costa County approximately 2.7 miles east of the Town of Oakley. The project site is located in the "off-island" portion of the Bethel Island Area, commonly known as the Hotchkiss Tract. The project site is located at the junction of Cypress Road and Bethel Island Road, and is generally bordered by Bethel Island Road on the west, Sandmound Boulevard on the north and east and agricultural uses on the south. The Cypress Lakes and Country Club project would be constructed on approximately 685.9 acres consisting of existing parcels of land. The project would consist of 1,330 single- family residential units. In addition, the project would include a 18-hole golf course with amenities, a swim and tennis club, a man-made lake and channels, a day care facility, parks, a potential school site, and a fire station. 1 The proposed residential development would be on lots ranging in size from approximately 5,000 square feet to 10,000 square `fed The overall residential lot density is approximately 5.40 units per acre (1,330 units'on 246 acres). The overall density of the project is 1.94 units per acre (1,330 units on 685.9 acres). Residential development on the southern portion of the site (south of Cypress Road) would be oriented toward the man-made lake to provide a lake-front living environment. A swim and tennis club would also be developed in this area to provide recreational opportunities for project and area residents. In addition, a day care center, park, fire station and potential school site would be located in this portion of the project site. The residential development north of Cypress Road would include a 18-hole golf course interwoven among the various neighborhoods. A clubhouse, driving range and storage maintenance facility would also be located in this area as well as several water channels. Monitoring and Reporting Overview The following Mitigation Monitoring and Reporting Program is organized as follows: Section II. Monitoring and Reporting Requirements for Mitigation Measures Contained in the Draft EIR for the Cypress Lakes and Country Club Project This section of the report presents the monitoring and reporting requirements necessary to comply with AB 3180. This section is divided into the same topic areas used in the Draft and Final EIRs (Land Use, Transportation, Air Quality, etc.). Under each of these headings, the adopted mitigation measure(s) (as adopted by the East County Regional Planning Commission) to reduce the significant impact to a less-than-significant level are presented. These are followed by the appropriate monitoring and reporting requirements necessary to ensure implementation of the mitigation measure. Under the Monitoring and Reporting Requirements section, specific tasks, their timing and the agency or party responsible is identified. Each of these tasks is assigned a number to allow tracking through the reporting process. Section III. Mitigation Compliance Report This section contains a sample Monitoring and Reporting Compliance Form which is to be filled out by the responsible agency or party upon complying with each specific monitoring and reporting task identified in Section II of this program. Each report should be filled out indicating the specific task number for which the report is being completed. All mitigation compliance reports should then be filed with the Contra Costa County Community Development Department. 2 Section IV. Master Mitigation Compliance Checklist This section contains a master checklist which contains each of the monitoring and reporting tasks identified in Section II of this program. This master checklist will provide a means to track the individual monitoring and reporting tasks and ensure compliance with all the mitigation measures adopted for the project. Completion of this checklist, along with the individual compliance reports, will meet the reporting requirements of AB 3180. How to Use this Report The Lead Agency (Contra Costa County) shall coordinate the implementation of mitigation measures for which other agencies are responsible. Mitigation Compliance Forms shall be submitted to: Director of Community Development or Appointee Contra Costa County Community Development Department 651 Pine Street, North Wing Martinez, California 94553 3 II. MONITORING AND REPORTING REQUIREMENTS FOR MITIGATION MEASURES 1. LAND USE, PLANNING AND PUBLIC POLICY Impact The project would add 1,330 dwelling units to the existing housing stock in price ranges between $175,000 to $400,000. The number of new units is below the 2,909 new units allowed by the General Plan. The project is consistent with the General Plan policy that development projects should be at or near density maximums to provide as much housing as possible. The project would contribute in-lieu fees for affordable housing of $3,333 per dwelling unit constructed, and in-lieu fees for the County's homeless fund. The project applicant may consider providing all, or a portion, of the project's affordable housing requirement on-site by designating and constructing affordable units as part of the project. Mitigation Measure • The project will pay a in-lieu affordable housing fee equal to $3,333 per residential unit. This fee shall be paid at the time of issuance of building permits for the project. As an alternative to the fees, the project applicant may construct a portion or all of the affordable housing units on-site. If this alternative mitigation is selected, the location and design of the affordable units should be submitted to the County for review and approval prior to filing final subdivision maps (3.1-1). Monitoring and Reporting Requirements. Task 1.1 Payment of Affordable Housing Fees The County shall receive payment of $3,333 at the time of issuance of each building permit for the project. (Responsibility: Contra Costa County) Task 1.2 On-Site Affordable Housing If the Board of Supervisors, in its approval for rezoning, permits the applicant to construct a portion or all of the affordable housing on-site, the County shall review the revised development plan and determine credit toward in-lieu fees prior to recordation of the final subdivision map. (Responsibility: Contra Costa County) Impact Because the proposed project is predominately residential, the project would result in a short-term unavoidable impact on East County's existing Jobs/Housing imbalance. 4 Mitigation Measure • The project marketing shall be oriented toward seniors and retired people to reduce commute traffic from the project (3.1-2). Monitoring and Reporting Requirements Task 1.3 Seniors Marketing The County Department of Community Development shall review marketing plans oriented toward seniors prior to issuance of building permits. (Responsibility: Contra Costa County) Impact The project would be required to pay the County's Protection Fee as well as in-lieu contribution to the County Homeless Trust Fund. Mitigation Measures • A Protection Fee shall be paid for each residential unit within the project to acquire development rights on agricultural land (and open space or wetlands areas) or to provide financing for farmers to continue agricultural production. The fee shall be determined by the County and paid upon the issuance of building permits for the project (3.1-3). • The project will pay an in-lieu contribution to the County Homeless Trust Fund. The amount of the contribution will be determined by the County and paid, pro-rata, upon the issuance of building permits (3.1-4). Monitoring and Reportin,- Requirements Task 1.4 Protection Fee The County shall collect a protection fee, as established by the County, upon issuance of each building permit for the project. (Responsibility: Contra Costa County) Task 1.5 County Homeless Trust Fund The County shall receive a pro rata in-lieu fee, as determined by the County, for the County Homeless Trust Fund prior to the issuance of building permits for the site. (Responsibility: Contra Costa County) 5 Impact The proposed project layout would conflict with an existing private easement from the Donnelley property to Cypress Road. Mitigation Measure • The project site plan should be revised to clearly depict the existing easement from the Dannelley property to Cypress Road. This easement shall be maintained in its existing location unless otherwise agreed to.by the property owner and the County (3.1-5). Monitoring and Reporting Requirements Task 1.6 Revise Final Subdivision Map (easement) The County shall review the final subdivision map to ensure that it has been revised to clearly depict the existing easement to the Dannelley property, unless otherwise agreed to by the property owner and the County. This revision shall be made prior to recordation of the final subdivision map. (Responsibility: Contra Costa County) Task 1.7 Provision of Easement The community park shall be constructed to allow for the existing easement to the Dannelley property, unless otherwise agreed to by the property owner and the County (Responsibility: Contra Costa County) 2. TRANSPORTATION/CIRCULATION Impact The addition of project traffic to the street network would substantially change traffic volumes on Cypress Road between the project and Highway 4. Beyond this location, traffic from the project would be more dispersed, but would still have a significant impact on Highway 4 between Oakley and the State Route 4/160 freeway. The traffic analysis assumed that portions of Cypress Road would be widened. All other intersections were calculated for capacity conditions without any additional roadway mitigation measures. During the AM peak hour, all intersections would operate at a satisfactory LOS with the existing plus project condition. PM peak hour traffic will also operate at satisfactory traffic conditions, assuming that partial improvements are constructed on Cypress Road. One other intersection would be critically impacted. At Neroly Road and Highway 4 (Main Street), traffic conditions would change from LOS "D" to LOS "E". Mitigations are planned for this intersection as a part of the ONBAG' Program, including widening the northbound approach to provide two left turn lanes. This improvement would restore the intersection LOS to "D. The project will add significant traffic 6 volumes to the roads in the immediate vicinity of the project. As a direct result of the project, Cypress Road will exceed capacity. These roads will require reconstruction and widening at the time of project construction. Mitigation Measures • Road Improvements at Proiect Entrance - Construct a new intersection at Cypress Road and Bethel Island Road, and on the approaches to this intersection. Widening shall extend 1,000 feet in each direction. To properly accommodate the proposed project traffic as well as future traffic from other parts of the area, the intersection would have the lane requirements shown on the following Figure 3.2-13. The southbound approach would be widened with one more lane. This intersection should be designed so that it can ultimately be consistent with a future extension to Byron Highway south of the intersection. Cypress Road will cross the levee just east of the entrance to the project. The vertical curvature of Cypress Lakes Road where it crosses the levee shall be submitted prior to final map approval and contain a 45 mph design speed. This project will include the installation of traffic signals that will be put into operation at the time that volumes meet Caltrans traffic warrants or when 500 units are completed and occupied. Note: This improvement could impact Cultural Resources (see Section 3.12). (Responsibility: Project Applicant) (3.2-1) • Bethel Island Road and Sandmound Boulevard - Bethel Island Road is planned to ultimately become a four-lane divided roadway between Cypress Road and the Bethel Island Bridge. This widening is not necessary as a result of the project, but there are interim improvements that should be accomplished. At Sandmound Boulevard, the intersection shall be improved and widened, and left turn lanes shall be constructed. Sandmound Boulevard shall be realigned to a right-angle intersection at Bethel Island Road. This project will also include the installation of traffic signals that will be put into operation at the time that volumes meet Caltrans traffic warrants. (Responsibility: Project Applicant) (3.2-3) • Cypress Road Widening - Complete the implementation of the Cypress Road widening from Machado Lane to east of Knightsen Road. This roadway improvement shall be in place before 1000 units are occupied at Cypress Lakes. It will include the installation of traffic signals at Sellers Road and Knightsen Road that would be put into operation at the time that volumes meet Caltrans traffic warrants. (Responsibility: Project Applicant) (3.2-3) • Sandmound Boulevard Improvements - Reconstruct Sandmound Boulevard from Bethel Island Road along the north border of the project and along the project's easterly frontage on Sandmound Boulevard. (Responsibility: Contra Costa County as a condition of future development) (3.2-4) 7 • Conformation with Measure C-The Cypress Lakes project would satisfy the requirements of Measure C by constructing the roadway improvements listed in Table 3.2-6 (A) at page 3-54 of the Draft EIR. (Responsibility: Project Applicant) (3.2-5) Monitoring and Reporting Requirements Task 2.1 Final Design Plans for Bethel Island Road/Cypress Road Intersection (Project Entrance Final design plans for the Bethel Island/Cypress Road intersection shall be reviewed and approved by the County Department of Public Works prior to recordation of the first phased subdivision map. (Responsibility: Contra Costa County Department of Public Works) Task 2.2 Construction of Intersection Improvements (interim) The interim intersection improvements shall be completed prior to the occupancy of the first homes on the site. Ultimate intersection improvements would be completed with completion of the Lesher Lakes project. The traffic signal shall be installed upon completion of the 500th home, or when traffic warrants are met, whichever comes first . (Responsibility: Project Applicant/Contra Costa County) Task 2.3 Final Design Plans for Bethel Island Road/Sandmound Boulevard Intersection The County Department of Public Works shall review and approve final design plans for the Bethel Island/Sandmound Boulevard intersection prior to the recordation of the final subdivision map. (Responsibility: Project Applicant) Task 2.4 Construction of Improvements at Bethel Island Road/Sandmound Boulevard The Bethel Island Road/Sandmound Boulevard intersection and Sandmound Boulevard improvements along the project frontage shall be completed per the conditions of project approval. (Responsibility: Project Applicant/Contra Costa County) Task 2.5 Final Design Plans -- Cypress Road Widening The County Department of Public Works shall review and approve final design plans for improvements to Cypress Road prior to recordation of the final subdivision map. (Responsibility: Contra Costa County Department of Public Works) 8 Task 2.6 Construction of Improvements -- Cypress Road from Machado Lane to Knightsen Avenue The improvements to Cypress Road between Machado Lane and Knightsen Avenue shall be completed prior to the occupancy of the 1000th unit on the project site (Responsibility: Project Applicant/Contra Costa County) Task 2.7 Construction of Improvements -- Cypress Road from Knightsen Avenue to Bethel Island Road These improvements to Cypress Road shall be completed prior to the occupancy of Lesher Landing project. (Responsibility: Contra Costa County) Task 2.8 Sandmound Boulevard Improvements The project site frontage along Sandmound Boulevard shall be reconstructed to meet County Code requirements. This construction shall be complete per the requirements of the conditions of project approval. (Responsibility: Contra Costa County) Impact The 1,330 houses proposed would generate 10,287 vehicle trip ends per day, including 730 trips during the AM peak hour and 1,036 trips during the PM peak hour. Trip generation for the various other project components, including the golf course and clubhouse, were estimated based on previous studies of similar facilities. Mitigation Measures • Bus Transit Service - While there is no current transit in the area, it can be expected that daily bus transit service, provided by Tri-Delta Transit, shall be provided to the Hotchkiss Tract and Bethel Island Area when a significant amount of the development in the area has been built and occupied. The situation shall be monitored, and transit service shall be started when about 1,000 homes have been completed in the area. This bus route shall be an extension of Routes 383 and/or 384 and will follow Cypress Road and Bethel Island Road to a terminal stop on Bethel Island. (Responsibility: Tri-Delta Transit/Contra Costa County) (3.2-6) • Participate in County TDM Program - The project shall be required to comply with the County residential TDM Ordinance, the County Growth Management Program, and the Bay Area Air Quality District regulations regarding transportation. TDM requirements of the County include the preparation and distribution of a TDM information program that shall include the provision of maps showing available transit routes, and information on 9 ridesharing and vanpool services to prospective home buyers. These types of measures can be expected to have only a relatively small'impact on reducing peak hour trips. Other studies have shown that TDM actions applied to a residential development can reduce the number of single occupant auto trips by 3-5 percent during the commute peak hours. (Responsibility: Project Applicant) (3.2-7) Monitoring and Reporting Requirements Task 2.9 Evaluate Bus Transit Service After completion of 1,000 homes on the project site, the County shall request that Tri-Delta Transit review the need for transit service to the Hotchkiss Tract/Bethel Island Area. (Responsibility: Contra Costa County) Task 2.10 TDM Information Packet The County shall review a TDM information packet prior to the issuance of building permits for the project. (Responsibility: Contra Costa County) Task 2.11 Implement/Monitor TDM Program The County shall receive annual reports documenting the results of the past years TDM program. (Responsibility: Project Applicant/Contra Costa County) Impact The internal circulation system of the projectshould be modified to provide improved circulation and conformance with future development in the Bethel Island Area. Mitigation Measures • Design level plans for the project entrance on Sandmound Boulevard shall be prepared and submitted to County Public Works Department for review and approval prior to approval of the first phased subdivision map. The design level plans shall provide for: adequate transition from the levee cross-section to grade at Sandmound Boulevard; adequate stopping distance; and adequate corner sight distance. (Responsibility: Project Applicant) (3.2-8) • Provide a right-of-way for a future roadway connection to the property south of Cypress Lakes, and construct the road up to the edge of the levee. This property could develop into a residential neighborhood, and shall be connected into Cypress Lakes at the time it develops, especially for school trips and other internal recreational trips. However, such a roadway connection shall not be the only access to this new area, and shall be provided only after Bethel Island Road is extended south across Rock Slough. This road shall be 10 Monitoring and Reporting Requirements Task 2.16 Heavy Truck Restrictions Heavy trucks shall be restricted from travelling on Cypress Road between the project site and SR 4 during peak commute hours. (Responsibility: Contra Costa County) Task 2.17 Repair of Road Damage Damage to Cypress Road and other adjacent roads resulting from construction truck traffic shall be repaired or paid for by the project applicant. The repairs and cost of the repairs shall be determined by the County Department of Public Works after completion of construction of the project. (Responsibility: Project Applicant/Contra Costa County) Impact Traffic generated by Cypress Lakes will contribute to cumulative traffic, and the project would be required to help mitigate these impacts by paying the Subregional Road Fee. Most of the traffic impacts of the short-term cumulative traffic can be mitigated to an insignificant level. However, there are two exceptions. The following mitigation measures should be addressed by the Cypress Lakes project if the Delta Expressway is not implemented, and if the problem is not mitigated by other sources. Mitigation Measures • Intersection of Neroly Road and SR 4 (Main St) - Widen the northbound approach to provide a double left turn from Neroly Road to SR 4. This will improve the V/C ratio from 0.93 ("E") to 0.81 ("D"). This will reduce this impact to a less than significant level. The project traffic will amount to about 10 percent of the traffic growth that is projected at this location. The applicant shall be required to pay a fair share fee equal to about 10 % of the cost of this improvement. (Responsibility: Project Applicant) (3.2- 14) • Intersection of Cypress Road and SR 4 - Widen the southbound approach to provide a double left turn lane for traffic from SR 4 to Cypress Road, and widen Cypress Road on the east leg of the intersection. This will improve the V/C ratio from 0.87 ("E") to 0.79 ("C"), and will reduce this impact to a less than significant level. The need for this improvement will depend entirely on the pace of development and the timing of the construction of the Delta Expressway. If the Cypress Corridor development moves quickly to implementation, prior to the completion of the Delta Expressway, this mitigation will be required. The need for this improvement will be reduced if the Laurel 13 Impact The daily increase in regional emissions (Reactive Organic Gases and Oxides of Nitrogen (two precursors of ozone), associated with the project would exceed the criterion (150 lbs/day). Therefore the project is considered to have a significant effect on regional emissions. Mitigation Measures • Comply with the County's Transportation Demand Management Program Ordinances 92- 31 by preparing and providing TDM information to prospective home buyers. The TDM information shall contain materials describing transit, ride sharing and van pool services. (Responsibility: Project Applicant) (3.3-5) • The project shall provide for transit stops along Cypress Road within the project site, along Cypress Lakes Drive, Sandmound Boulevard and Country Club Drive. (Responsibility: Project Applicant) (3.3-4) • The proposed project design includes pedestrian/bicycle paths linking recreational and residential uses within the site (see Section 3.9). In addition to these facilities, bicycle parking areas shall be provided at all recreational facilities within the project site (Golf Course Clubhouse, Beach Club and Public Ballpark). (Responsibility: Project Applicant) (3.3-7) Monitoring and Reporting Requirements See Tasks 2.11 and 2.12 above. Task 3.5 Transit Stops The County shall review road plans for Cypress Road extension, Cypress Lakes Drive, Sandmound Boulevard and Country Club Drive to ensure that they include appropriate transit stops pursuant to Tri-Delta Transit requirements. The transit stops shall be installed as part of the subdivision improvements. (Responsibility: Contra Costa County) Task 3.6 Bicycle Parking Areas Provide bicycle parking areas at all recreational facilities within the project. The County shall require bicycle parking facilities to be installed prior to completion of each recreational facility. (Responsibility: Project Applicant/Contra Costa County) 16 applicant. The Plan shall be submitted to Contra Costa County and the California Department of Fish and Game for review and approval prior to approval of the project's final subdivision maps. (Responsibility: Project Applicant/California Department of Fish and Game/Contra Costa County) (3.4-3) • To minimize impacts to wildlife movement along this drainage channel, road crossings shall utilize clear span bridges. In the alternative, culverts shall be used and designed as large as possible to minimize impacts to wildlife movement. The design of all bridges and/or culverts to be placed along the primary drainage channel ("main drain") shall be submitted for review and approval to Contra Costa County Department of Public Works, Reclamation District 799 (if RDD-799 accepts drainage) and the California Department of Fish and Game prior to filing a final subdivision map. (Responsibility: Project Applicant/Contra Costa County/Reclamation District 799/California Department of Fish and Game) (3.4-4) Monitoring and Reporting Requirements Task 4.1 Detailed Channel Enhancement Plan Contra Costa County and the California Department of Fish and Game shall review and approve the Channel Enhancement Plan prior to recordation of the final subdivision map. (Responsibility: Contra Costa County/California Department of Fish and Game) Task 4.2 Implementation of Channel Enhancement Plan Monitor implementation of the Channel Enhancement Plan to ensure compliance with the requirements of the County, the California Department of Fish and Game, and the U.S. Army Corps of Engineers. A monitor shall be present during construction of the channels to ensure compliance with the Plan. (Responsibility: Contra Costa County) Task 4.3 Road Crossings of Channels Contra Costa County, RD-799, and the California Department of Fish and Game shall review the design of all bridges/culverts crossing the main drain prior to recordation of the final subdivision map. (Responsibility: Contra costa County/RD-799/California Department of Fish and Game) Task 4.4 Construct Road Crossings Monitor construction of road crossings of the channels to ensure compliance with the approved plans (Responsibility: Contra Costa County) 18 Impact The proposed project would result in approximately 0.75 acres of wetlands being filled for development of the proposed project. Filling of wetlands on the project site may adversely affect special-status plants and animals. Mitigation Measures • The project plans include a draft Habitat Mitigation and Monitoring Plan which shall to replace wetlands on-site, in a ratio of 3 acres for every 1 acre impacted (0.75 acres impacted to be replaced with 2.28 acres of new wetland) by enlarging and enhancing the existing wetlands on the project site and providing buffer areas around wetlands. The Habitat Mitigation and Monitoring Plan shall be reviewed and approved by the County and the California Department of Fish and Game prior to filing a final subdivision map. (Responsibility: Project Applicant/Contra Costa County/California Department of Fish and Game) (3.4-5) • Wetlands and waterways impacted by the proposed project are considered waters of the United States and therefore come under the jurisdiction of Section 404 of the Clean Water Act. Filling in waters of the United States requires a permit from the, U.S. Army Corps of Engineers. The project applicant is required to obtain a permit from the U.S. Army Corps of Engineers before filling of any wetlands or waters on the project site only if filling more than one acre. The California Department of Fish and Game shall be notified regarding project activities in the vicinity of the main drain pursuant to Fish and Game Code Section 1600 et. seq. (Responsibility: Project Applicant) (3.4-6) • The project shall pay the County Protection Fee, as required by the County General Plan, for acquiring development rights on wetland areas off-site. The Protection Fee shall be paid upon the issuance of building permits for the project. (Responsibility: Project Applicant) (3.4-7) Monitoring and Reporting Requirements See Task 1.4 above regarding County protection Fees. Task 4.5 Habitat Mitigation and Monitoring Plan The County and the California Department of Fish and Game shall review the habitat Mitigation and Monitoring Plan prior to recordation of the final subdivision map. (Responsibility: Contra Costa County/California Department of Fish and Game) 19 Task 4.6 Implementation of Habitat Mitigation and Monitoring Plan Monitor implementation of the Habitat Mitigation and Monitoring Plan to ensure compliance with the requirements of the County and the California Department of Fish and Game. A monitor shall be present on-site during implementation of the Habitat Mitigation and Monitoring Plan to ensure compliance. (Responsibility: Contra Costa County) 5. VISUAL QUALITY Impact The project would result in changing the existing visual character of the project site to one of a suburban residential community with various recreational uses. This change would substantially alter the existing visual condition. This would be considered an unavoidable impact of the project. Mitigation Measures • Landscape criteria for the proposed golf course, parks, common areas, project levees and the channels. Landscaping shall consist primarily of low grasses and wildflowers with some introduced shrubs and trees. (3.5-1) • Landscape guidelines for the proposed levee system. These guidelines are designed to be consistent with the landscape guidelines of the State Reclamation Board. A list of suitable plant species is provided as part of the guidelines. (3.5-2) • A landscape strip shall be provided outside the project levee to provide screening of the levee along Bethel Island Road and Sandmound Boulevard. The landscape strip shall be a minimum of 10 feet wide and be located sufficiently outside the levee cross-section to not hinder maintenance of the levee. The landscape strip shall be planted with trees and shrubs to provide maximum screening. Maintenance of the landscape strip shall be carried out by the homeowners' association or special district but not the public agency responsible for maintenance of the project levee. (3.5-3) • Residential units shall be limited to two stories not to exceed 30 feet. (3.5-4) • Minimum setbacks along arterial roadways shall be 200 feet, and 100 feet from the center line of the roadway to the exterior wall of any living space along collectors (Cypress Road Extension). (3.5-5) 20 • Sideyard setbacks shall vary taking into account: 1) structures should not block solar access for heating and cooling; 2) space between buildings shall increase in relation to their height; and 3) periodic view corridors to water areas shall be provided. (3.5-6) Monitoring and Reporting Requirements Task 5.1 Landscape Guidelines The County shall review and approve detailed landscape guidelines for each of the following: 1) the golf course, 2) parks, 3) common areas and 4) levees, which address the requirements of the mitigation measures prior to recordation of the final subdivision map. (Responsibility: Contra Costa County) Task 5.2 Landscape Strip Revise the final subdivision map to depict a 10-foot landscape strip along the project's frontage on Bethel Island Road and Sandmound Boulevard. (Responsibility: Project Applicant) Task 5.3 Height of Residential Units The County shall not approve any building permits for homes over 30 feet in height on the project site. (Responsibility: Contra Costa County) Impact Views of the project site from Bethel Island Boulevard, Sandmound Road and other vantage points around the project perimeter would be partially blocked by a landscaped flood control levee which would surround the project. The degree of impact would be higher for residences closest to the levee. Mitigation Measures • The levee landscape guidelines shall be finalized once the public agency to be responsible for maintaining the levees is determined. The levee landscape guidelines shall then be submitted to the public agency responsible for maintenance of the levees for review and approval prior to the installation of any landscaping on the levees. (Responsibility: Project Applicant) (3.5-7) • A landscape maintenance district, or other funding source consisting of the property owners within the project site, shall be established for the proposed project to pay for long-term maintenance of public recreation areas within the project site. The project applicant shall submit a proposal for the landscape maintenance district to the County for 21 approval prior to approval of the project's final subdivision map. (Responsibility: Project Applicant) (3.5-8) Monitoring and Reporting Requirements Task 5.4 Formation of a Maintenance District Form a Maintenance District to provide for the long-term maintenance of public recreation facilities (i.e., parks) on the project site. The County shall ensure that a landscape maintenance district is formed prior to occupancy of the first homes on the site. (Responsibility: Contra Costa County) 6. NOISE Impact Existing residences adjacent to the site, particularly along Sandmound Boulevard, would be exposed to a short-term impact from construction noise. Mitigation Measures • All general construction activity shall be limited to the hours of 7:30 a.m. to 5:00 p.m. on weekdays only. • Operations of any machine or device which generates a noise level greater than 95 Db at 50 feet shall be prohibited wherever feasible. • Route heavy construction traffic along existing Cypress Road and the proposed Cypress road to minimize the impact on existing residences. No construction traffic shall be routed along Bethel Island Road or Sandmound Boulevard. • Prohibit construction trucks from parking along existing Cypress Road west of the project entrance. • Locate noisy stationary equipment, such as compressors or pumping stations away from existing residences to reduce their noise impact. (Responsibility: Project Applicant) (3.6-2) Monitoring and Reporting Requirements Task 6.1 Construction Period Noise Conditions of Approval 22 The construction period noise mitigation shall be made conditional on project approval. (Responsibility: Contra Costa County) Task 6.2 Implementation of Construction Period Noise Mitigation Periodically monitor the construction site for compliance with the noise mitigation measures and conditions of approval. (Responsibility: Contra Costa County) Impact Proposed housing along the extension of Cypress Road within the project would be exposed to a existing and future DNL of 65 Db. This is 5 Db over the County goal for normally acceptable outdoor noise levels but is within conditionally acceptable noise levels. Mitigation Measure • In order to avoid adverse noise levels at homes to be located along the extension of Cypress Road through the project, the project has been designed to provide a 100 foot set- back along Cypress Road. The 100 foot set-back shall be from the center line of the roadway to the nearest exterior wall of each residence located along Cypress Road. The 100 foot set-back will reduce the noise level at these residences to a DNL of 60 Db which is consistent with the County's noise goals for residential uses. (3.6-3) Monitoring and Reporting Requirements Task 6.3 Cypress Road Setbacks The County shall review all building plans for lots located along Cypress Road so that the 100-foot setback is maintained. (Responsibility: Contra Costa County) 7. HYDROLOGY AND DRAINAGE Impact The project would increase the area of impermeable surfaces and increase storm water runoff. The proposed channel/lake system and storm drainage network would reduce the project's drainage impacts. On-site storm drainage that previously was collected in ditches and flowed off-site to RD-799 pumps, would, for the most part, be collected on site and terminate in the proposed channel/lake system. During storm periods when excess water accumulates on the site, waters from the lake would then be pumped to ultimate disposal in Sand Mound Slough by a pump station that would be constructed as part of the development. 23 Mitigation Measures • On-site storm drainage facilities (lake, channels and golf course detention facilities) shall be . constructed to both protect property and to provide for public safety by accommodating the 100-year storm event. (3.7-1) • Dewatering structures (discussed in the Water Quality section) shall be constructed at those points where underground storm drainage pipes enter the channel/lake system in order to facilitate the periodic flushing and cleaning of the underground pipes. (3.7-2) • Drainage ditches shall be constructed along the exterior toe of the proposed levee system to catch that runoff from the exterior slope of the levees. The drainage ditches shall discharge into existing drainage ditches along the perimeter of the project. (3.7-3) • Maintenance of on-site stone drainage improvements within the public right-of-way, or in suitable easements, shall be performed by the County of Contra Costa. Stormwater pump station maintenance shall be performed by the public entity selected to be responsible for the operation and maintenance of the perimeter levee. (3.7-4) Monitoring and Reporting Requirements Task 7.1 Design of Storm Drainage Facilities Submit detailed drainage improvement plans to Contra Costa County Department of Public Works and RD-799 for both on-site and off-site facilities. The County shall review and approve these plans prior to recordation of the final subdivision map. (Responsibility: Project Applicant/Contra Costa County) Task 7.2 Construction of Drainage Improvements Periodically, monitor construction of the project drainage facilities for compliance with the approved drainage plans. (Responsibility: Contra Costa County/RD- 799) Task 7.3 Maintenance of Drainage Improvements Maintenance responsibilities shall be determined prior to completion of storm drainage improvements (Responsibility: Project Applicant/Contra Costa County/RD-799) 24 Impact The 685.9 acre project site would be removed from the FEMA flood hazard zone by construction of a perimeter levee. Material for construction of the levee would be obtained from the excavation of the interior channels-lake system. The levee would be constructed to standards adopted by FEMA for an Urban Standard Levee. Mitigation Measures • The design of the project levee shall be in accordance with the standards and requirements of the Federal Emergency Management Agency for an Urban Standard Levee. Provisions shall be designed into the project levee to allow for a future increase in height of four feet to allow for the "greenhouse effect". During the design of the project levee, the crest elevation shall be increased by an amount equivalent to projected long term settlement. (3.7-5) • The side slopes of the project levee shall be planted and irrigated to reduce erosion, and to provide dust control, in accordance with the project's landscape guidelines and the guidelines of the public agency responsible for maintenance of the levee. (3.7-6) • Adequate easements shall be granted to the maintaining authority in order to provide for maintenance and upgrading of the levee, and to prohibit encroachments onto the levee. (3.7-7) • To minimize the risk of liquefaction beneath the perimeter levees, the loose clean and silty sand of depths of 10 to 15 feet shall be reworked and densified. Over excavation and compaction of soils shall be utilized to densify the soils. (3.7-8) • The levee landscape guidelines shall be finalized once the public agency responsible for maintaining the levees is determined. The levee landscape guidelines shall then be submitted to the public agency responsible for maintenance of the levees for review and approval prior to installation of any landscaping on the levees (same as mitigation measure 3.5-7) (Responsibility: Project Applicant) (3.7-9) • A detailed emergency evacuation plan based on the project's proposed emergency evacuation plan shall be prepared in cooperation with RD-799 and the governmental agency that ultimately accepts the internal levee system prior to approval of the project's final subdivision map. The evacuation plan shall include at a minimum the following measures: • Criteria for determining when a emergency exists • Methods for notifying and evacuating area residents 25 • Identification of agencies and individuals responsible for emergency response and public evacuation • Plans for returning evacuees to their homes after an emergency has passed. (Responsibility: Project Applicant) (3.7-10) Monitoring and Reporting Requirements Task 7.4 Levee Design FEMA and RD-799 shall review and approve detailed levee design plans prior to construction activities for the levees beginning on the site (Responsibility: FEMA/RD-799) Task 7.5 Construction Techniques Construction techniques for the levees shall be reviewed and approved by Contra Costa County and RD-799 prior to issuance of grading permits (Responsibility: Contra Costa County/RD-799) Task 7.6 Monitoring Levee Construction Periodically monitor construction of the project levee to ensure compliance with the approved levee design and construction plans (Responsibility: RD-799) Task 7.7 Detailed Levee Landscape Plans FEMA and RD-799 shall review and approve detailed levee landscape plans prior to issuance of grading permits (Responsibility: FEMA/RD-799) Task 7.8 Installation of Levee Landscaping Monitor the installation of landscaping on the levee to ensure compliance with the approved landscape plans (Responsibility: RD-799) Task 7.9 Emergency Evacuation Plan RD-799 shall review and approve a detailed Emergency Evacuation Plan prior to issuance of the first occupancy permit for the project (Responsibility: RD-799) 26 Impact Existing soils within the project site would be removed(for the lake/channels) to construct the proposed levee system. The proposed project would have a short-term impact on groundwater as a result of dewatering of near-surface groundwater for excavation for the internal levees,lake, channels and installation of utilities. The localized dewatering activities would not affect adjacent properties because dewatering would occur far enough from existing residences and draw down would only occur on the project site immediately under or adjacent to the dewatering area. In addition, the project plans include a groundwater monitoring plan. Mitigation Measure • The proposed groundwater monitoring plan shall be made a condition of project approval. A final groundwater monitoring plan shall be submitted for review and approval by the County prior to filing a final subdivision map. (Responsibility: Project Applicant/Contra Costa County/RD-799) (3.7-11) Monitoring and Reporting Requirements Task 7.10 Final Groundwater Monitoring Plan The County shall review and approve a final Groundwater Monitoring Plan prior to recordation of the final subdivision map (Responsibility: Contra Costa County) Task 7.11 Implementation of Groundwater Monitoring Plan Periodically monitor compliance with the County Groundwater Monitoring Plan. The Groundwater Monitoring Plan shall be implemented prior to any grading occurring on the project site (Responsibility: Contra Costa County) Impact The project would not have an impact on the condition of the existing RD-799 levee system. However, the project site does provide funding for continued maintenance of the RD-799 levee system and RD-799 may ultimately be responsible for maintenance of the proposed levee system. Mitigation Measure • The project site shall continue to be a part of RD-799 and shall be prohibited from seceding from this district, even if removed from the flood hazard zone by the proposed internal levee system, to provide the district with a continued long-term source of funding 27 for maintenance of the existing RD-799 levee system. (Responsibility: Contra Costa County/Project Applicant) (3.7-12) Monitoring and Reporting Requirements Task 7.12 Continued Support of RD-799 Require the project site to remain a part of RD-799 as a condition of project approval (Responsibility: Contra Costa. County) Impact Increased surface runoff from the new impervious surfaces and the golf course may have impacts on the water quality of the channels-lake and ultimately the Delta. Urban runoff can contain substantial quantities of pollutants such as organic pesticides, heavy metals, nutrients, petroleum products, and suspended solids. To address this potential impact, the project plans include a water quality management plan and maintenance criteria for the golf course. However, proper implementation is necessary to ensure adequate water quality. Mitigation Measures • A final maintenance plan for the Golf Course shall be submitted for review and approval by the County, prior to filing a final subdivision map. The final maintenance plan shall build on the maintenance criteria established in the project plans and identify standard maintenance and management practices to be carried out on the Golf Course. Specific maintenance procedures shall be identified regarding the use of pesticides, herbicides, and fertilizers. An emphasis of the maintenance plan should be to reduce potential leaching into local groundwater resources. The maintenance and management plan shall also outline specific irrigation practices designed to reduce water consumption. (Responsibility: Project Applicant) (3.7-13) • The CC&R's shall contain information on the use and disposal of undesirable materials such as motor oil, paints, garden pesticides and other household products. (Responsibility: Project Applicant) (3.7-14) • A street sweeping program shall be provided to reduce urban pollutant run off into the proposed lake and channels. The street sweeping shall be provided by the County through its existing street sweeping program. Alternative measures could include funding of the street sweeping program by the homeowner's association. (Responsibility: Contra Costa County/Homeowners Association) (3.7-15) • A final channel-lake operation and maintenance plan shall be submitted for review and approval prior to filing a final subdivision map. The plan shall be based on the applicant's proposed lake-channel management plans utilizing plants, flushing, aeration 28 and other techniques to maintain water quality without chemicals. (Responsibility: Project Applicant) (3.7-16) • The project shall comply with all the requirements of the County's NPDES permit requirements. The project applicant shall provide the County with the appropriate documentation regarding compliance with NPDES requirements prior to the issuance of grading permits for the project. (Responsibility: Project Applicant) (3.7-17) Monitoring and Reporting Requirements Task 7.13 Final Golf Course Maintenance Plan The County and RD-799 shall review and approve a final Golf Course Maintenance Plan prior to issuance of building permits for the golf course. (Responsibility: Contra Costa County/RD-799) Task 7.14 Implementation of Golf Course Maintenance Plan Periodically monitor compliance and success of the Golf Course Maintenance Plan. (Responsibility: Contra Costa County) Task 7.15 Informational Packet The County shall review and approve an informational packet addressing the issue of disposal of undesirable materials prior to issuance of the first occupancy permits for the project. (Responsibility: Contra Costa County) Task 7.16 Distribution of Informational Packet Distribute the informational packet (see Task 7.15) to each project resident as part of the CC&R's (Responsibility: Project Applicant) Task 7.17 Street Sweeping Provide a street sweeping program. If not funded by the County, it shall be funded by the project residents. The County shall ensure that the street sweeping program is in place prior to occupancy of the first homes on the site (Responsibility: Project Applicant/Contra Costa County) Task 7.18 Channel-Lake Maintenance Plan Contra Costa County and RD-799 shall review and approve a final Channel-Lake Maintenance Plan prior to recordation of the final subdivision map (Responsibility: Contra Costa County/RD-799) 29 Task 7.19 Compliance with NPDES Requirements Review all grading plans, drainage plans, etc. for compliance with the County's NPDES permit requirements prior to approval of grading permits and building permits (Responsibility: Contra Costa County) 8. GEOLOGY, SEISMICITY AND SOILS Impact The project would expose new structures to the potential impacts of liquefaction. Due to the "Generally High" liquefaction potential on the project site and County policies, this impact would be considered potentially significant. Mitigation Measures • Excavate, rework and densify the loose clean and silty sands under the levee to a depth of 10 to 15 feet. • The Kleinfelder report analyzed alternative approaches for mitigating liquefaction impacts. The project should be required to adhere to these approaches. The specific approach will depend on site-specific conditions and analysis. However, the project applicant should follow the reviewed and approved recommendation of the Kleinfelder report. A report documenting the methods used in the field to reduce liquefaction potential should be submitted to the Public Works Department and the public agency responsible for maintenance of the levee system. (Responsibility: Project Applicant) (3.8-5) • Building plans for each structure to be constructed on the project site shall include an evaluation and recommendations to ensure satisfactory performance in the event of an earthquake and liquefaction on the project site. The building plans shall be reviewed and approved by Contra Costa County prior to the issuance of building permits. (Responsibility: Project Applicant) (3.8-8) Monitoring and Reporting Requirements Task 8.1 Documenting Levee Construction Methods Upon completion of levee construction, a report documenting the construction methods used in the field shall be submitted to the County and RD-799 (Responsibility: Project Applicant/Contra Costa County/RD-799) 30 Task 8.2 Building Plans Review each building plan for appropriate design to ensure satisfactory performance in the event of an earthquake and liquefaction on the project site, prior to issuance of building permits (Responsibility: Contra Costa County) Impact Construction of the project would result in grading over much of the site for construction of the proposed homes, golf course, lakes and other facilities. These activities would expose soils to wind and water erosion. Because the site is located in an area of strong winds, wind erosion could result in a significant loss of soil without mitigation. Mitigation Measures • The erosion control measures proposed for the project shall be a part of all construction activities. These measures include the following: • Existing vegetated areas shall be left undisturbed until construction of site improvements is actually ready to commence. • All disturbed areas shall be protected from both wind and water erosion upon the completion of grading activities. • Runoff shall be directed away from all areas disturbed by construction, if practical. • Temporary check dams, sediment ponds, or siltation basins shall be used to trap eroded soils, and prevent their discharge into storm drain pipes. • To the extent possible, major site development work involving earth moving and excavations shall be scheduled for the dry season. • Areas used for stockpiling and staging construction equipment and materials shall be located so that unchecked runoff from these areas does not enter the storm drain system. (Responsibility: Project Applicant) (3.8-4) 31 Monitoring and Reporting Requirements See Task 3.3 for Dust Control Measures. Task 8.3 Erosion Control Measures Make erosion control measures conditions of project approval (Responsibility: Contra Costa County) Task 8.4 Monitoring Erosion Control Periodically monitor compliance and effectiveness of erosion control measures throughout construction of the project (Responsibility: Contra Costa County/Dust Control Coordinator) Impact The potential for subsidence from dewatering would be short-term(only during dewatering activities) and would only occur in the immediate area of dewatering activities. Dewatering activities are expected to occur during the excavation for the lake and channels, construction of the levee and'installation'of underground utilities. Dewatering activities would effect the top 15 to 20 feet, which would not impact most domestic wells which are generally below the depth of the dewatering activities (Bohely, 1992). The localized dewatering activities would not cause subsidence on adjacent properties because draw down would only occur on the project site immediately under or adjacent to the dewatering area. Mitigation Measures • Groundwater monitoring plans to provide early detection of changes in the groundwater level and to allow adjustments in the construction techniques if necessary. Monitoring wells and settlement plates will be placed on the project site and surrounding properties to control the groundwater level. (3.8-3) • The ground settlement monitoring plan shall be finalized and submitted to the County for review and approval prior to beginning any construction or dewatering activities. The plan shall identify the location of all monitoring wells, and provide specifics on well completion and the method and frequency of monitoring. Similarly, the plan shall identify settlement plates as well as contingency plans to control subsidence or mitigate subsidence related damage. (Responsibility: Project Applicant) (3.8-6) 32 Monitoring and Reporting Requirements Task 8.5 Groundwater Settlement Monitoring The County and RD-799 shall review and approve the Groundwater Settlement Monitoring Plan prior to issuance of grading permits for the project (Responsibility: Contra Costa County) Task 8.6 Implementation of Groundwater Settlement Monitoring Plan The County shall monitor implementation of the Groundwater Settlement Monitoring Plan prior to any grading activities or dewatering activities commencing on the site (Responsibility: Contra Costa County) 9. FIRE PROTECTION Impact The project would increase fire protection service demands on the fire districts by increasing the number of structures and population within the project area. To reduce the project's impacts on fire services, the project would include construction of a fire station near the project entrance at Cypress Road. This station would satisfy the County's standard that fire stations be located within one and one-half miles of development, and satisfactory to the Bethel Island and Oakley Fire Districts for maintaining the five minute / 1.5 mile response standard. The proposed project, therefore, is not expected to have an adverse impacts on fire protection facilities. Mitigation Measures • The project will dedicate a site and construct a new fire station on the project site in lieu of fire protection fees as determined by the County. The site and station shall meet all applicable requirements of the appropriate Fire District (Oakley FPD or Bethel Island FPD). The fire station shall be operational prior to the first homes on the site being occupied. If necessary a special district fee shall be augmented to provide adequate funding to fully staff the new station. (Responsibility: Project Applicant/Fire District) (3.9-1) • If the project is required to pay fees, the Fire District fees shall be based on the fees in effect at the time of the issuing of building permits. (Responsibility: Project Applicant) (3.9-2) • All building plans shall meet the applicable Uniform Building and Fire codes. Fire protection agencies shall be afforded the opportunity to review and comment on plans 33 prior to the issuance of building permits for the projects. (Responsibility: Contra Costa County/Fire Districts) (3.9-3) Monitoring and Reporting Requirements Task 9.1 Fire Station Design The appropriate Fire District shall review and approve the fire station design prior to issuance of building permits for the fire station (Responsibility: Fire District) Task 9.2 Construction of Fire Station Construction of the fire station shall be complete prior to. the issuance of occupancy permits for residential uses on the site or other criteria as established by the Fire District. (Responsibility: Contra Costa County) Task 9.3 Special District Funding If necessary, a special district shall be formed to provide funding for staffing the fire station. The special district shall be in place prior to completion of the fire station (Responsibility: Contra Costa County) Task 9.4 Fire Protection Fees The Fire District shall receive the appropriate fire protection fees with the issuance of building permits (Responsibility: Contra Costa County) Task 9.5 Compliance with Uniform Fire Code Review all building plans for compliance with the Uniform Fire Code prior to issuance of building permits (Responsibility: Contra Costa County/Fire District) 10. POLICE PROTECTION Impact The project would result in the addition of approximately 3,247 persons population within the County sheriff's service area. This would result in the need for new officer positions and equipment. 34 Mitigation Measure • The proposed project shall pay a fair-share fee equal to the cost of providing 465 square feet of new Sheriff Department facilities, based on the County standard of 155 square feet per 1,000 residents. The fee shall be calculated and paid at the time of issuance of building permits for the project. (Responsibility: Project Applicant) (3.9-4) Monitoring and Reporting Requirements Task 10.1 Sheriff Fees The County shall receive sheriff fees equal to the cost of 465 square feet of new sheriff facilities or as determined by the County, pro rata at the time of issuance of building permits (Responsibility: Contra Costa County) 11. SCHOOLS Impact The project would generate approximately 665 new elementary and middle school enrollments and approximately 253 new high school enrollments. Based on the project's student generation and the local school district's school facility requirements, the proposed project would require the construction of approximately one new elementary school, 30% of a new middle schools, and 20% of a new High Schools. The project includes a possible school site of approximately 7.4 acres. This site is proposed to mitigate the project's impacts on the local school district. The OUESD has indicated that a 10 acre school site would be desired. Mitigation Measures • The applicant and the school district may enter into a short-term funding agreement prior to recordation of the subdivision map. The agreement would ensure that matching funds are provided for the completion of construction documents necessary for the district's application(s) for State funding. The amount of short-term funding would be credited to the applicant's full school impact fees which are paid upon issuance of building permits. (Responsibility: Project Applicant/OUSD/LUHSD) (3.9-5) • School impact fees are projected to be insufficient to cover the project's share of facilities required to serve new students in the area. If no state or local funding is available, the project applicant is encouraged to work with districts to determine additional school fees that may be paid as building permits are issued. (Responsibility: Project Applicant/OUSD/LUHSD) (3.9-6) 35 • If required by the Oakley Unified School District, the school site shall be enlarged from 7.4 acres to 10 acres. (Responsibility: Project Applicant) (3.9-7) • If the proposed on-site school site is determined by the OUESD to be unacceptable, the applicant shall pay an in-lieu fee to the OUESD for the purchase of an appropriate school site. (Responsibility: Project Applicant/ School District) (3.9-8) Monitoring and Reporting Requirements Task 11.1 Short-Term Funding Agreement A short-term funding agreement may be entered into prior to recordation of the final subdivision map (Responsibility: Project Applicant/OUESD/LUHSD) Task 11.2 School Impact Fees The County shall not issue building permits until school impact fees are paid. These fees are paid prior to issuance of building permits. A portion, or all, of these fees may be satisfied with provision of the school site. (Responsibility: Contra Costa County) Task 11.3 Supplemental Funding The project applicant and school district should attempt to agree on additional school fees prior to recordation of the final subdivision map (Responsibility: Project Applicant/OUESD/LUHSD) Task 11.4 School Site If required by the Oakley Unified School District, the final subdivision map shall be revised to include a 10-acre school site (Responsibility: Project Applicant) Task 11.5 School Site Fees If the proposed school site is not acceptable to the school districts, the project applicant shall pay the full school impact fees to the district as required by State law. (Responsibility: Project Applicant) 36 12. PARKS AND OTHER RECREATION FACILITIES Impact The project would include 170 acre semi-private golf course, 60 acres of channels and lake, a 1.5 acre beach club, approximately 33 acres of parks, and a day care facility. The project is consistent with the park land/recreation requirements of the County. Mitigation Measures • The project shall construct and dedicate the large community park to the County which would then be responsible for continued maintenance of the park. If this is unacceptable to the County, funding for maintenance of the community park shall be provided through a special district. (Responsibility: Project Applicant) (3.9-9) • The community park shall be designed so that active recreational use areas are located outside the power line easement. Active uses to be located outside the easement include: baseball diamonds, soccer fields and play ground areas. Uses permitted within the easement shall be passive recreation and landscape areas. (Responsibility: Project Applicant) (3.9-10) • The project applicant shall prepare a child care needs assessment based upon the projected demographics and density of the proposed project. The needs assessment shall be submitted to the Community Development Plan prior to approval of the final phase map for the portion of the project which includes the day care site. (Responsibility: Project Applicant) (3.9-11) Monitoring and Reporting Requirements Task 12.1 County Park Design Revise the design of the county park to exclude active recreational uses from under the powerline easement. The design shall be reviewed and approved by the County prior to recordation of the final subdivision map (Responsibility: Contra Costa County) Task 12.2 Construction of the County Park Construct the county park prior to implementation of any phase south of Cypress Road Extension. (Responsibility: Project Applicant/Contra Costa County) f 37 Task 12.3 Maintenance of the County Park The county park shall be maintained by the County. However, if not acceptable to the County, a special district shall be formed to fund long-term maintenance. The special district shall be formed prior to completion of the county park (Responsibility: Contra Costa County) Task 12.4 Child Care Study The County shall receive a child care needs assessment prior to recordation of the final subdivision map (Responsibility: Contra Costa County) 13. OTHER GOVERNMENT SERVICES: MOSQUITO ABATEMENT DISTRICT Impact The Contra Costa Mosquito Abatement District (CCMAD) notes that the environmental conditions in the area indicate that the project would cause an increase in the level of service required from CCMAD. Golf courses, parks and water detention basins proposed as part of the project can lead to mosquito problems year round. Mitigation Measure • CCMAD shall be provided the final design plans for wetland mitigation areas and golf course maintenance and irrigation for review and comment prior to their approval. (Responsibility: Contra Costa County) (3.9-12) Monitoring and Reporting Requirements Task 13.1 CCMAD Review Forward the wetland mitigation, irrigation and golf course plans to CCMAD for review prior to recordation of the final subdivision map (Responsibility: Contra Costa County) 38 14. WATER SERVICE Impact Water requirements for the project would amount to approximately 1.7 million gallons per day (mgd). This can be broken down into 884,150 mgd for domestic use and 805,200 mgd for landscaping. The project is proposing to utilize existing groundwater resources for irrigation of the golf course, parks, wetlands, and certain levee areas. The Oakley Water District appears to be the logical provider of domestic water service to the proposed project and has provided a "will serve" letter to the project applicant confirming that water capacity is available to serve this project through its buildout. Mitigation Measures • Implement a groundwater management plan to address water requirements for irrigating the golf course and parks and to monitor changes in the groundwater table. The groundwater management plan shall also address the management of pesticides and measures to be taken to reduce potential impacts on groundwater resources. In addition, the plan shall identify what areas, and in what sequence, water will be discontinued to portions of the golf course and parks in the event of water cutbacks because of drought or substantial lowering of the water table. The plan shall be approved by the County prior to filing a final subdivision map. (Responsibility: Project Applicant) (3.10-1) • Design into the golf course the use of grasses that are drought tolerant to limit the amount of water necessary for irrigation. (Responsibility: Project Applicant) (3.10-2) • Require all structures to confirm to the California Health and Safety Code Section 1792.3 and the Public Resources Code Section 25402 with regard to maximum flow rates through plumbing fixtures. (Responsibility: Project Applicant) (3.10-3) • Provide homeowners with alternative landscaping opportunities such as xeriscape landscaping for builder installed front yards. (Responsibility: Project Applicant) (3.10- 4) • Design water distribution systems in accordance with American Water Works Association standards. (Responsibility: Project Applicant) (3.10-5) • Install cathodic protection where corrosive environments are found and metallic water line products must be used. (Responsibility: Project Applicant) (3.10-6) • Landscaping materials should be drought-tolerant to reduce overall landscape and irrigation requirements. The landscape areas should conform with the requirements of the County's Water Efficient Landscape Ordinance. (Responsibility: Project Applicant) (3.10-7) 39 Monitoring and Reporting Requirements Task 14.1 Groundwater Management Plan The County and RD-799 shall review and approve the groundwater management plan prior to recordation of the final map (Responsibility: Contra Costa County/RD-799) Task 14.2 Groundwater Monitoring The County and RD-799 shall receive groundwater monitoring reports on a bi- annual basis. Each report shall summarize the prior six-month's management activities and results (Responsibility: Project Applicant/Contra Costa County/RD-799) Task 14.3 Golf Course Grasses Review landscape plans for the golf course for use of drought-tolerant grasses (Responsibility: Contra Costa County) Task 14.4 Review of Plumbing Fixtures Review all building plans for compliance with the California Health and Safety Code Section 1792.3 and Public Resource Code Section 25402 (Responsibility: Contra Costa County) Task 14.5 Landscaping Information Provide landscaping information to home-owners regarding xeriscape and other water-conserving landscaping techniques upon purchase of each home (Responsibility: Project Applicant) Task 14.6 Review of Water Distribution System Review public improvement plans for conformance with American Water Association Standards and for the use of cathodic protection prior to their approval (Responsibility: O W D) Task 14.7 Conformance with County Landscape Ordinance Review landscape plans for conformance with the County Water Effluent Landscape Ordinance prior to their approval (Responsibility: Contra Costa County/OWD) 40 Impact .The project proposes to obtain its domestic water supply from the existing OWD mains located at the intersection of Highway 4 and Cypress Road in Oakley. From that point, the project would construct two separate 12" pipelines, that are periodically interconnected, to the project site. The 12" pipelines would have sufficient capacity to serve the proposed project as well as some limited additional development within the Bethel Island area. Mitigation Measure • The project shall be required to construct, or pay a fee equal to, the necessary off-site water system improvements to serve the proposed project. The size and design of these facilities shall meet all applicable standards and requirements of the Oakley Water District and local Fire District Standards. The project shall be reimbursed for the cost of constructing facilities which have the capacity to serve future development in the planning area served by the facilities. The necessary off-site water facilities shall be completed and operational prior to the first homes being occupied on the site. (Responsibility: Project Applicant) (3-10-8) Monitoring and Reporting Requirements Task 14.8 Off-Site Water Improvement Plans The OWD shall review and approve off-site water improvement plans (Responsibility: OWD) Task 14.9 Construction of Off-Site Water System Prior to the issuance of occupancy permits for the project, all off-site water improvements to serve the site shall be complete (Responsibility: Contra Costa County) Task 14.10 Reimbursement Agreement The OWD and the Project Applicant shall enter into a reimbursement agreement for off-site improvements constructed by the project applicant which have a total capacity above that necessary to serve the project site (Responsibility: Project Applicant/OWD) 41 15. SEWAGE DISPOSAL Impact The project would result in a significant increase in wastewater generated from the project site. Based on wastewater generation factors provided by the Oakley Sanitary District, the proposed project would generate approximately 360,000 gallons/day (or 0.36 mgd) based on 270 gallons/unit day x 1,330 units. The most logical provider of sewer service for the project is the Ironhouse Sanitary District because 75% of the proposed project site is located within their existing service boundaries. The project applicant has requested that the remainder of the project site be annexed to the Ironhouse Sanitary District. The Ironhouse Sanitary District appears to have adequate capacity to serve the project and has provided a "will serve" letter to the project applicant. However, there may be several off-site improvements necessary to serve the project. Mitigation Measures • The project applicant shall be required to construct all necessary sewage collection facilities on-site to serve the project. These facilities shall be built to district standards and appropriate easements for district maintenance provided. The sewage collection facilities should be installed prior to the first homes being occupied. (Responsibility: Project Applicant) (3.10-9) • A hydraulic analysis of the force main shall be conducted to determine the capacity of the existing force main and any improvements that may be necessary to accommodate the proposed project. This analysis shall be conducted prior to approval of the project's final subdivision map. The project shall pay its fair share of any improvements necessary to the force main to serve the project. The fair-share fee shall be paid upon approval of the first phased map. (Responsibility: Ironhouse Sanitary District/Project Applicant) (3.10-10) • The project shall be required to pay the full costs of any increase in pumping capacity or new pump station(s) necessary to serve the project. The need and cost for these improvements shall be determined by the Ironhouse Sanitary District prior to approval of the final map. (Responsibility: Project Applicant) (3.10-11) • A reimbursement agreement shall be entered into between the project applicant and the Ironhouse Sanitary District whereby the project applicant would be reimbursed for the portion of the cost of new facilities which have the capacity to serve areas in addition to the project. The reimbursement shall be paid out of fees paid by future developments. (Responsibility: Project Applicant) (3.10-12) 42 Monitoring and Reporting Requirements Task 15.1 On-Site Sewage System Plans The Ironhouse Sanitary District shall review and approve on-site sewage system plans prior to installation (Responsibility: Ironhouse Sanitary District) Task 15.2 Installation of On-Site Sewage System The sewage system shall be operational prior to the issuance of occupancy permits for the project (Responsibility: Contra Costa County) Task 15.3 Hydraulic Analysis Complete a hydraulic analysis of the existing force prior to recordation of the final subdivision map (Responsibility: Ironhouse Sanitary District) Task 15.4 Improvements to Force Main The Ironhouse Sanitary District shall receive a fair share payment of the cost of improvements to the force main prior to providing service to the project (Responsibility: Ironhouse Sanitary District) Task 15.5 Pumping Capacity Analysis An analysis of the necessary pumping capacity to serve the site shall be conducted prior to recordation of the final subdivision map (Responsibility: Ironhouse Sanitary District) Task 15.6 Cost of Pumping Improvements Make the necessary pumping improvements to serve the site, as determined by the Ironhouse Sanitary District, prior to providing service to the project (Responsibility: Ironhouse Sanitary District) Task 15.7 Reimbursement Agreement The Ironhouse Sanitary District and the Project Applicant .shall enter into a reimbursement agreement (or credit agreement) for. off-site improvements constructed by the project which have additional capacity above that necessary to serve the project (Responsibility: Project Applicant/Ironhouse Sanitary District) 43 16. ELECTRICAL SERVICE Impact Electric service would be supplied to new development by PG&E. The existing transmission lines and substation appear to have adequate capacity to provide service to the project. Mitigation Measures • The project shall include the undergrounding of all new electrical service lines necessary to serve the project site. Electrical lines should be placed in relatively water tight conduits according to PG & E standards. This shall be completed prior to the first houses being occupied. (Responsibility: Project Applicant/PG&E) (3.10-13) • The need to upgrade off-site electrical lines shall be determined by PG&E prior to approval of the final map. If off-site reinforcement is necessary, the project applicant shall be required to pay the project's fair-share, if any, of the reinforcement. (Responsibility: Project Applicant) (3.10-14) Monitoring and Reporting Requirements Task 16.1 Undergrounding of Electrical Lines All new electrical lines serving the project site shall be undergrounded. This shall be completed prior to the issuance of occupancy permits for homes in that phase (Responsibility: Contra Costa County) Task 16.2 Off-Site Electrical Improvements Project plans shall be reviewed to determine the need for off-site electrical system improvements (Responsibility: PG&E) 17. NATURAL GAS SERVICE The proposed project would have minimal impact on natural gas service because it would be served by electricity only. If desired,individual project residents could use propane if allowed by the homeowner's association. No additional mitigation necessary. 44 18. TELEPHONE SERVICE Impact The project would require the replacement of the switch on Bethel Island and the extension of new telephone cables to the project site. According to PUC regulations, costs of line and equipment installation would be borne by the developer and Pacific Bell. According to County policy, distribution lines would need to be placed underground in relatively watertight conduits and vaults, thereby avoiding visual impacts and prolonging the life of the equipment and cables. Mitigation Measures • Place distribution lines underground. (Responsibility: Project Applicant/Pacific Bell) (3.10-15) • Install telephone cables in relatively water-tight conduits and vaults. (Responsibility: Project Applicant/Pacific Bell) (3.10-16) Monitoring and Reporting Requirements Task 18.1 Telephone Cables Install all new telephone cables on the project site underground in watertight conduits prior to the issuance of occupancy permits for homes within that phase (Responsibility: Project Applicant/Pacific Bell) 19. SOLID WASTE COLLECTION/DISPOSAL The proposed project would not result in an adverse impact on solid waste collection and disposal services, therefore no mitigation measures are proposed. 20. LIGHTING Impact The project includes street lighting and additional lighting associated with individual residential units and recreational uses. The street lighting would be installed in accordance with Contra Costa County Code(Title 9)requirements and maintained by Contra Costa County. Street lights produce "glow" which could impact adjacent residents. 45 Mitigation Measure • Project street lights shall utilize down focused lights and other features to reduce glare. The design of street lights shall be submitted for review and approval to the County Public Works Department for review and approval prior to approval of the final map. (Responsibility: Project Applicant) (3.10-17) Monitoring and Reporting Requirements Task 20.1 Street Light Design The County Department of Public Works shall review and approve street light design prior to recordation of the final subdivision map (Responsibility: Contra Costa County Department of Public Works) Task 20.2 Installation of Street Lights Install street lights in accordance with the approved plans. Street lights shall be operational prior to the issuance of the first occupancy permits for that phase of the project (Responsibility: Contra Costa County) 21. HUMAN HEALTH Soil Contamination Impact The project site could potentially contain contaminated soils in those areas where heavy equipment is stored, repair facilities are located and where the above ground storage tanks are located. Mitigation Measure • Conduct soil sampling in areas of the site where heavy equipment is stored and where repair facilities and above ground storage tanks are located. If soil contamination is identified, removal and remediation of the material shall occur before excavation or construction activities commence in these areas. The Contra Costa County Health Department should supervise and authorize any soil sampling procedures and remediation. (Responsibility: Project Applicant) (3.11-2) 46 Monitoring and Reporting Requirements Task 21.1 Soil Sampling Conduct soil sampling in areas where heavy equipment is stored, repair facilities are located, and where above-ground storage tanks are located. The soil sampling shall be done prior to issuance of grading permits. If contaminated soil is found, Task 21.3 would apply (Responsibility: Project Applicant/Contra Costa County) Task 21.2 Soil Remediation If soil contamination is found, a remediation plan shall be prepared for review and approval by the County Health Department. Soil remediation efforts shall be completed prior to the issuance of grading permits for the area where contamination is identified (Responsibility: Contra Costa County/Contra Costa County Health Department) Mosquitos Impact The project would involve the construction of lakes, a golf course and other water related facilities including wetland mitigation sites, drainage facilities. These facilities may provide breeding habitat for mosquitos if not properly maintained. Mitigation Measures • The Contra Costa Mosquito Abatement District (CCMAD) shall be consulted during the final design of any wetland mitigation sites to be created on the project site. (Responsibility: Project Applicant/Contra Costa County/CCMAD) (3.11-3) Monitoring and Reporting Requirements See Task 13.1 Electrical Transmission Lines Impact The project site is located in close proximity to large electrical transmission lines and natural gas drill easements (no active gas sites). Although some of these risks are speculative, as a result of the project's location, project residents could be exposed to certain health risks. 47 Mitigation Measure • Each residence within the project site shall include in the CC&Rs a clause stating that the incoming property owner is aware of the specific human health issues related to living near electrical transmission lines and drill sites. (Responsibility: Project Applicant) (3.11-5) Monitoring and Reporting Requirements Task 21.3 Notification of Potential Human Health Issues The County shall review the project CC&R's to ensure they include a notice advising incoming property owners of hazards associated with adjacent land uses (electrical transmission lines and drill sites). (Responsibility: Contra Costa County) 22. CULTURAL RESOURCES Impact Because the project site is known historically to contain cultural resources, including the possibility of human burials, the proposed project may result in the disruption of cultural resources as a result of the grading and excavation necessary to construct various components of the project. Mitigation Measures • Due to the existence of subsurface cultural materials along the western perimeter of the CA-CCo-134 site area and the recommendations relative to site CA-CCo-139 (below), significant ground disturbance shall be avoided in an area of approximately 11 acres (700 x 700 feet [213 x 213 meters])(see Appendix H). The proposed uses in this area (internal levee, natural gas drilling site, fire station, community park) are not expected to result in significant ground disturbance. However, all construction activity in this area shall be closely monitored to preserve known resources and to determine the presence of any previously unknown subsurface resources in the CA-CCo-134 area. Should sterile soil (e.g., topsoil) be placed over the site for landscaping purposes, rubber-tired construction vehicles shall be used throughout the site area and excavation for landscaping or irrigation shall be utilized in fill material only. Should it be necessary to excavate through native soils, an archaeologist shall be present to monitor soil removal for the presence of cultural materials. (Responsibility: Project Applicant) (3.12-1) 48 • Significant ground disturbance shall be avoided in the area surrounding site CA-CCo-139; from the 0-foot (sea level) contour to the mound apex at 6.5 feet above sea level (see Appendix H). The proposed uses in this area (Community Park, extension of Cypress Road) are not expected to result in significant ground disturbance. However, all construction activities shall be closely monitored to preserve known resources present in this area. It is understood that two private parcels of land on the mound are not included in the project proposal. These recommendations do not apply to those parcels unless they are incorporated into the project proposal at some future time. Should any subsurface disturbance occur on the mound through the removal of structures or foundations, an archaeological monitor shall be present to observe soils for the presence of cultural materials. Should sterile soil (e.g., topsoil) be placed over the site for landscaping purposes,rubber-tired construction vehicles shall be used throughout the site area and that excavation for landscaping or irrigation shall be utilized in fill material only. Should it be necessary to excavate through native soils, an archaeologist shall be present to monitor soil removal for the presence of cultural materials. (Responsibility: Project Applicant) (3.12-2) • Construction at the fire station, which would be within the area of archaeological sensitivity for site CA-CCo-139, shall be closely monitored and work stopped immediately if cultural materials are encountered. If it is determined that construction is not feasible, the project applicant shall be required to find an alternate site outside the archaeologically sensitive area. (Responsibility: Project Applicant) (3.12-3) • Lot No.10 in Neighborhood 1 shall be removed or redrawn in a manner that avoids.the archaeologically sensitive area associated with CA-CCo-139. (Responsibility: Project Applicant) (3.12-4) • Lot Noll in Neighborhood 1 shall be removed or redrawn in order to avoid the archaeologically sensitive area associated with CA-CCo-139. (Responsibility: Project Applicant) (3.12-5) • The area including and immediately surrounding site CA-CCo-647 should be avoided to preclude impacts to this important resource (see Appendix H). Should sterile soil (e.g., topsoil) be placed over the site for landscaping purposes, rubber-tired construction vehicles shall be used throughout the site area and excavation for landscaping or irrigation shall be utilized in fill material only. Should it be necessary to excavate through native soils, an archaeologist shall be present to monitor soil removal for the presence of cultural materials. (Responsibility: Project Applicant) (3.12-6) • The rear lot lines of lots No.29 and 30 in Neighborhood 7 shall be redrawn in a manner that avoids the archaeologically sensitive area associated with CA-CCo-647. (Responsibility: Project Applicant) (3.12-7) 49 • In the event that avoidance of the preceding cultural resource sites is not feasible, a data recovery or "excavation plan" shall be developed pursuant to the requirements of CEQA Appendix K, Part V and subject to the limitations defined in Part VI. (Responsibility: Project Applicant) (3.12-8) • An archaeological monitor shall be present when grading, excavation, trenching and other soil disrupting activities are carried out in any of the mapped archaeologically sensitive areas as defined in Appendix H. These activities/areas include, for example, the Cypress Road extension; levee construction/excavation/ compaction; possibly, demolition of existing homes; fire station construction; and the parking lot for the playing fields. (Responsibility: Project Applicant) (3.12-9) • An archaeological monitor shall be on-call when grading,excavation, trenching and other soil disrupting activities are carried out on the project site. In the event that a prehistoric site, burial, or historic resource is encountered during construction of the project, the project engineer shall be obligated to temporarily stop or relocate construction activities and notify the archaeological monitor immediately. In the event a significant prehistoric or historic resource is identified, no further construction shall be permitted in that location until a mitigation plan can be formulated and implemented. (Responsibility: Project Applicant) (3.12-10) • In the event human remains are discovered during construction, excavations shall be halted at that location. Any finds of human remains must be reported to the Contra Costa County Coroner's Office. In the event that the find is determined to be prehistoric, the Native American Heritage Commission must be notified within 24 hours to alert them of the find and to permit the designation of a Native American representative. Consultation between the archaeological consultants in charge of monitoring, Contra Costa County, and the Native American representative shall then determine the course of action to be taken with the burial in question. Ideally, if removal is undertaken, time shall be allowed for study of the remains and any associated grave goods prior to their return to the Native American Community for reburial at a location of their selection. (Responsibility: Project Applicant) (3.12-11) • A report of findings and analyses of all archaeological data recovered during testing/excavation,monitoring and any mitigation procedures undertaken shall be prepared by a qualified archaeologist. (Responsibility: Project Applicant) (3.12-12) • Sections 5097.98 and 5097.99 of the Public Resources Code also call for "protection to Native American human burials and skeletal remains from vandalism and inadvertent destruction". To achieve this goal, the construction personnel on the project shall be instructed as to the potential for discovery of cultural or human remains, and both the need for proper and timely reporting of such finds, and the consequences of failure thereof. (Responsibility: Project Applicant) (3.12-13) 50 • The Native American Heritage Commission (NAHC) in Sacramento shall be contacted regarding potential Native American concerns, values, and traditional use areas relative to the proposed project site and vicinity. There is a potential for disturbance of previously undiscovered Native American human remains during construction of the project. An established agreement shall be entered into with the NAHC and/or local Bay Miwok tribal representatives prior to the discovery of such remains, should any be discovered. A typical agreement would specify when, in the event of a discovery, Native American involvement would occur, and the treatment and ultimate disposition of ancestral remains. (Responsibility: Project Applicant) (3.12-14) • The proposed intersection improvements at the project entrance and Bethel Island Road shall be realigned to the north as much as possible to avoid impacting site CA-CCo-138. (Responsibility: Project Applicant) (3.12-15) • The alignment of any future extension of Bethel Island Road south of Cypress Road shall be as far east as feasible to avoid site CA-CCo-138, taking into consideration safety factors. This may result in the need to move the project levee along the project's westerly boundary up to 50 feet-to the east. (Responsibility: Project Applicant/Contra Costa County) (3.12-16) Monitoring and Reporting Requirements Task 22.1 Conditions of Approval Include the cultural resource mitigation measures in the conditions of project approval (Responsibility: Contra Costa County) Task 22.2 Cultural Resource Monitoring Monitor construction activities in the areas identified. Monitoring shall be done by a qualified archaeologist who has the authority to stop construction activities (Responsibility: Contra Costa County) Task 22.3 Revision of Subdivision Map , Revise the project subdivision map to exclude Lots No. 10 & 11 in Neighborhood 1 and Lots No. 29 & 30 in Neighborhood 7, or in such a way that these lots avoid archaeologically sensitive areas. In addition, the project levee south of Cypress Road along the project's western boundary shall be moved approximately 50 feet to the east to allow for the future extension of Bethel Island Road to the south and to avoid archaeologically sensitive areas. The County shall review the plans to ensure that these revisions are made on the final subdivision map prior to its recordation (Responsibility: Contra Costa County) 51 23. ENERGY Impact An average dwelling unit could be expected to consume approximately 4,869 kilowatt hours (kwh)/year of electricity. Total energy consumption of the proposed homes would be approximately 6.47 million kilowatt hours/year of electricity. The project has proposed to incorporate design features in the project homes so that energy consumption would be reduced. The goal of the project would be to exceed the energy efficiency standards of Title 24 by 10%. Mitigation Measure • Building plans for each house should include energy conservation features such as passive solar heating, additional insulation and other features so that Title 24 efficiency standards (1991) will be exceeded by at least 10%. These features shall be reviewed and approved by the County Building Department as part of the building permit review process. (Responsibility: Project Applicant) (3.13-1) Monitoring and Reporting Requirements Task 23.1 Energy Conservation Review energy conservation features for each house for exceedance of the Title 24 efficiency standards by 10% (Responsibility: Contra Costa County) 52 III. MITIGATION COMPLIANCE REPORT Project Name/Reference: Date: Time: Monitoring Task: (Include # and title, See Section II of Monitoring Report) COMPLIANCE MONITORING BASELINE OBSERVATION Compliance Status: If Unacceptable: Remedial Action Implemented Acceptable (Discuss below) Remedial Action Needed (Discuss Below) Unacceptable Additional Follow-up Needed (No remedial Action) Observations: Recommendations: Preparers Name: Representing (Agency/Firm): Signature: Date: 53 VI. MASTER MITIGATION COMPLIANCE CHECKLIST >'>`SOtC: > >:: :::« ;;; < : G '>< MA :..MITI AU U € > >O MONITORING/REPORTING TASK WAS TASK (Refer to Section II for a detailed DATE EFFECTIVE? discussion of each task) IMPLEMENTED (If Applicable) COMMENTS .LAN p' >::::>:<E`T AN NIN AN`Ui:P .... .U G.. ... U G aL C ..............................:...:.......::.:.........................................--..................................... ..................... ......................................... . Task 1.1 Payment of Affordable Housing Fees Task 1.2 On-site Affordable Housing Task 1.3 Seniors Marketing Task 1.4 Protection Fee Task 1.5 County Homeless Trust Fund Task 1.6 Revise Final Subdivision Map (Easements) Task 1.7 Provision of Easement r::<:::<> CU LAT :... . a or C� . 2 :: TANStO . . .T . ... . .............. .. .:. ................... .......................................... ....................................................... Task 2.1 Final Design Plans for Bethel Island Road/ Cypress Road Intersection (Project Entrance) Task 2.2 Construction of Intersection Improvements Task 2.3 Final Design Plans for Bethel Island Road/Sandmound Boulevard Intersection Task 2.4 Construction of Improvements at Bethel Island Road/Sandmound Boulevard Task 2.5 Final Design Plans - Cypress Road Widening 54 . : STER fTl. ATI N MPLI G a D AN GHf± .UST . ..... MONITORING/REPORTING TASK WAS TASK (Refer to Section II for a detailed DATE EFFECTIVE? discussion of each task) IMPLEMENTED (If Applicable) COMMENTS Task 2.6 Construction of Improvements - Cypress Road from Machado Lane to Knightsen Avenue Task 2.7 Construction of Improvements - Cypress Road to Bethel Island Rd. Task 2.8 Sandmound Boulevard Improvements Task 2.9 Evaluate Bus Transit Service Task 2.10 TDM Information Packet Task 2.11 Implement/Monitor TDM Program Task 2.12 Right-of-Way for Future Connection to the South Task 2.13 Cypress Road Connection to Sandmound Boulevard Task 2.14 Bicycle Paths within Project Task 2.15 Bicycle Paths Off-site Task 2.16 Heavy Truck Restrictions Task 2.17 Repair of Road Damage Task 2.18 Neroly Road/SR 4 Improvements Task 2.19 Cypress Road/SR 4 Improvements :.;::... ..: '3<..:.:.:...Al R QUA Task 3.1 Dust Control Measures Task 3.2 Truck Speed Limit 5.5 :;::;.::.... ... MASTER Wff.IGATION:CQMRI tAt±1 E MONITORING/REPORTING TASK WAS TASK (Refer to Section II for a detailed DATE EFFECTIVE? discussion of each task) IMPLEMENTED (If Applicable) COMMENTS Task 3.3 Dust Control Coordinator Task 3.4 Suspension of Construction Activities Task 3.5 Transit Stops Task 3.6 Bicycle Parking Areas ::::.. ....Y. . .- WILDEFAND ....15 TO . ..........................N : Task 4.1 Detailed Channel Enhancement Plan Task 4.2 Implementation of Channel Enhancement Plan Task 4.3 Road Crossings of Channels Task 4.4 Construct Road Crossings Task 4.5 Habitat Mitigation and Monitoring Plan Task 4.6 Implementation of Habitat Mitigation and Monitoring Plan 5 .... VISUAQCI ......: . Task 5.1 Landscape Guidelines Task 5.2 Landscape Strip Task 5.3 Height of Residential Units Task 5.4 Formation of a Maintenance District 56 ::::`::. >>MAS"1`EA"`:::<;:::<:< >:<:>::,;:::<::<:< :;:: : <>P;: ::;>:;>:;>:>::>:>:: <:::::;>::::<:>;.<: :: �;:>:`T€€ <'>> > >'<> >' '>> ........... >>x x. MITIGATI N M O Cfl. 1,tANHt S MONITORING/REPORTING TASK WAS TASK (Refer to Section II for a detailed DATE EFFECTIVE? discussion of each task) IMPLEMENTED (If Applicable) COMMENTS �; ;:� iO..S t `'' ' f' ' f: 55' >': :;;;< t < s? `2 ' ' 25 :< N.. I E.:::: . Task 6.1 Construction Period Noise Conditions of Approval Task 6.2 Implementation of Construction Period Noise Mitigation Task 6.3 Cypress Road : Setbacks .. YAAU:'7 : H . D © 4R Task 7.1 Design of Storm Drainage Facilities Task 7.2 Construction of Drainage Improvements Task 7.3 Maintenance of Drainage Improvements Task 7.4 Levee Design Task 7.5 Construction Techniques Task 7.6 Monitoring Levee Construction Task 7.7 Detailed Levee Landscape Plans Task 7.8 Installation of Levee Landscaping Task 7.9 Emergency Evacuation Plan Task 7.10 Final Groundwater Monitoring Plan Task 7.11 Implementation of Groundwater Monitoring Plan Task 7.12 Continue Support of RD-799 57 ... ............... ....................................... ............ MASTER'MI : MP',!': H TIGaTICiN... 4.11 E.0. E :::::.::ST:.;.: : .;;<:«::::::::::::::.::::::::::::::::::::::::::::.......... MONITORING/REPORTING TASK WAS TASK (Refer to Section II for a detailed DATE EFFECTIVE? discussion of each task) IMPLEMENTED (If Applicable) COMMENTS Task 7.13 Final Golf Course Maintenance Plan Task 7.14 Implementation of Golf Course Maintenance Plan Task 7.15 Informational Packet Task 7.16 Distribution of Informational Packet Task 7.17 Street Sweeping Task 7.18 Channel-Lake Maintenance Plan Task 7.19 Compliance with NPDES Requirements ..... i$ L?rE{}LOGY, SEISMICITY.AND $Ct Task 8.1 Documenting Levee Construction Methods Task 8.2 Building Plans Task 8.3 Erosion Control Measures Task 8.4 Monitoring Erosion Control Task 8.5 Groundwater Settlement Monitoring Plan Task 8.6 Implementation of Groundwater Settlement Monitoring Plan .....,:::::: FIRS RRtT: Task 9.1 Fire Station Design Task 9.2 Construction of Fire Station Task 9.3 Special District Funding Task 9.4 Fire Protection Fees 58 MA T XX T MITI (xN Ct}M...4.AN # 4.ST....... ... ....... :.:.:. .;..:.. S .ER G�► .I MONITORING/REPORTING TASK WAS TASK (Refer to Section II for a detailed DATE EFFECTIVE? discussion of each task) IMPLEMENTED (If Applicable) COMMENTS Task 9.5 Compliance with Uniform Fire Code j.. . .. .. l. R „PHQT��:.:::Cfl....:::::.: .:....:.::::::. ;:.:;.;:.;:.;:.;:... Task 10.1 Sheriff Fees ..................................................................................... . ........ Task 11.1 Short-Term Funding Agreement Task 11.2 School Impact Fees Task 11.3 Supplemental Funding Task 11.4 School Site Task 11.5 School Site ... :. Fees... : . . 1. : . :PARKSAND.:OTHERRECREATON. rACIT, ... ......... ....;.: . ......... ...;;:........::. ::. Task 12.1 County Park Design Task 12.2 Construction of the County Park Task 12.3 Maintenance of the County Park Task 12.4 Child Care Study 13, UTHER' CVRNMENT:SERCIwS MOSQlJITO ABATEMENT ►tSTR CT. „.. . ...... ...... ........ ... ........ ..... ......... ......... Task 13.1 CCMAD Review . .. WATER SERVICE . Task 14.1 Groundwater Management Plan Task 14.2 Groundwater Monitoring Task 14.3 Golf Course Grasses Task 14.4 Review of Plumbing Fixtures Task 14.5 Landscaping Information 59 .. MASTER MtTIG TO CgMPL114NG1<:�HEG�LI$T .:.:.:.:::..:. . ........;::::;: MONITORING/REPORTING TASK WAS TASK (Refer to Section II for a detailed DATE EFFECTIVE? discussion of each task) IMPLEMENTED (If Applicable) COMMENTS Task 14.6 Review of Water Distribution System Task 14.7 Conformance with County Landscape Ordinance Task 14.8 Off-Site Water Improvement Plans Task 14.9 Construction of Off-Site Water System Task 14.10 Reimbursement Agreement 1;�� ; ;. S:E :AG S 05 . . .. Task 15.1 On-Site Sewage System Plans Task 15.2 Installation of On-Site Sewage System Task 15.3 Hydraulic Analysis Task 15.4 Improvements to Force Main Task 15.5 Pumping Capacity Analysis Task 15.6 Cost of Pumping Improvements Task 15.7 Reimbursement Agreement ........... :&: E. LECTI IOAI SERVICE; . «<' >: ` <`< ;;;<'' .. : » > < > > >...... < ><; << > > ......... Task 16.1 Undergrounding of Electrical Lines Task 16.2 Off-Site Electrical Improvements 18: ......:.TELIWRHdNE SER;: C . 60 :; ASTER MIT,EGATIQ.: .CD IAE CHEfCL1.ST.......... » MONITORING/REPORTING TASK WAS TASK (Refer to Section II for a detailed DATE EFFECTIVE? discussion of each task) IMPLEMENTED (If Applicable) COMMENTS Task 18.1 Telephone Cables �:j I Task 20.1 Street Light Design Task 20.2 Installation of Street Lights M ... Task 21.1 Soil Sampling Task 21.2 Soil Remediation Task 21.3 Notification of Potential Human Health Issues 2< L7(1RA't FtESOU.R'.'ES. :>'<< > < ;'' ;' ................>< 2 CU C Task 22.1 Conditions of Approval Task 22.2 Cultural Resource Monitoring Task 22.3 Revision of Subdivision Map Task 23.1 Energy Conservation 61 EXHIBIT 91C11 CONDITIONS OF APPROVAL FOR DEVELOPMENT PLAN 3032-90 AND REZONING 2918-RZ AS APPROVED BY THE EAST COUNTY REGIONAL PLANNING COMMISSION ON APRIL 5, 1993 1 The.development shall be based on the following submitted exhibits except as modified by the conditions below. These conditions of approval incorporate and are an addition to all approved mitigation measures. Staff recommends that the following conditions also be recommended to the Board of Supervisors for the approval of 2918-RZ and D.P. 3032-90. The conditions of approval for this subdivision may be modified by the conditions approved by the Board of Supervisors for 2818-RZ and D.P. 3032-90. A. Revised vesting tentative map, final development plan and phasing plan dated received July 2, 1992. The maximum number of units approved for this project 14; ........... is 1,330 residential units. Th' B. Wetlands Delineation Report done by Huffman & Associates, Inc. dated July 17, 1991. C. Geotechnical and investigation report, Phase 1 study, done by Kleinfelder & Associates dated December, 1988. D. Informational report far the proposed levee system byBohley/Maley Associates dated August 20, 1992. E. Preliminary environmental assessment of hazardous sites on the site by Kaldveer Associates dated February 27, 1989. F. Evaluation proposal levee bordering Cypress Lakes Project by Kleinfelder & Associates dated February 2, 1993. G. Special Status Species Survey done by Huffman & Associates dated October, 1991. 2. Prior to recording the final map on any phase of this projector issuance of a grading permit, the final development plan #3032-90 and request for rezoning 2918-RZ shall have been approved by the Board of Supervisors in a manner similar to the approval' for this subdivision. 3. The length of approval of the tentative map as well as for the accompanying final development plan and rezoning shall be for three years. One 3-year extension may be granted subject to proper request and approval. a ifi �i ....... ot, ixx` Root! 0 ;-4 MA.:....JIMOX, Nit- P.id. T lil: A. , ' 2 _ ` Project Phasing 5. The phasing plans ioacceptable aaproposed. Phasing may bemodified subject tothe review and approval of the Zoning Adhniniotrotor. 6. The following actions shall take place before various phases Of the project 8na developed: . A. Thepark areas within Phase 1 shall be developed and landscaped prior to occupancy ofresidences in Phase 1 . An acceptable landscape, irrigation and equipment plan, including public reStro0ro8 shall be submitted for the Zoning Administrator's administrative app/ova|. Means t0finance the park shall be developed prior to recording the final nnop for Phase 1 of the subdivision. The park areas within Phase 1 shall be developed and landscaped prior to occu- pancy of residences. The park areas in Phase 3 shall be developed and landscaped prior tOoccupancy Ofresidences \n Phase 3. B. The beach club, Svvi,n club area shall be developed prior to occupancy of residences in Phase 2. This will require a further final development plan approval. The beach-swim club shall beopen tothe public either byreasonable fee or open membership. C. The various tot lot areas will be developed prior to occupancy Vfthe various ' phases in which they are located. Thetrails connecting the neighborhoods with the SrnaU tot lot/park areas shall be developed in the appropriate phase. Trail plans ahoU be approved by the Public Works Department and the Zoning Administrator. D. The golf course and gU|fc|ubhU 0ue8 Si�� �h� be developed phnrtooccupancy of residences in Phase 4. The golf clubhouse site and driving range will require approval of further final development plan. The golf course-clubhouse shall be open to the public by payment of n reasonable fee. Any restaurant/bar in the golf clubhouse shall be open to the public. E. ' The levee trails south of Cypress Road extension shall be developed prior to occupancy of residences in Phase 1 . The levee trails north of Cypress Road extension ahmU be developed prior to occupancy of naaidanoex in Phase 4, including the development of the trail across the site along the east/west channel. Trails shall be opened to the public. °~. �� ' r: 3 Street Addressinq 7. Prior to filing the Final Map, plans shall be submitted for review by the Community Development Department, Graphics Section, to obtain addresses and for street name approval (public and private). Alternate street names should be submitted in the event of duplication and to avoid similarity with existing street names. The Final Map cannot be certified by the Community Development Department without the approved street names and the assignment of street addresses. Police Services 8. The owner of the property shall participate in the provision of funding to maintain and augment police services by voting to approve a special tax for the parcels created by this subdivision action. The tax shall be $200 per parcel annually (with appropriate future Consumer Price Index (CPI) adjustment). The election to provide for the tax must be completed prior to the filing of the Parcel Map. The property owner shall be responsible for paying the cost of holding the election. The fee for election costs will be due at the time that the election is requested by the owner. EMF Notification 9. Where a lot is located within 300 feet of a high voltage electric transmission line, the applicant shall record the following notice: "The subject property is located near a high voltage electric transmission line. Purchasers should be aware that there is ongoing research on possible potential adverse health effects caused by the exposure to a magnetic field generated by high voltage lines. Although much more research is needed before the question of whether magnetic fields actually cause adverse health effects can be resolved, the basis for such an hypothesis is established. At this time no risk assessment has been made." When a Final Subdivision Public Report issued by the California Department of Real Estate is required, the applicant shall also request that the Department of Real Estate insert the above note in the report. Energy Conservation 10. At least 30 days prior to filing a final map on Phase 1, the applicant shall submit to the Zoning Administrator for the review and approval: A. Methods to provide for future passive or natural heating or cooling opportunities within the subdivision and the design of the residences and swimming pools to the extent feasible; 4 B. Evidence that the desirability of participating in the P.G. & E. energy conserva- tion "Incentives for Builders" program has been considered. Should the applicant choose not to participate, the applicant shall indicate in writing the reasons for the decision. Residences energy conservation shall exceed Title 24 requirements by 10%. Farm Operation Notice 11 . The following statement shall be recorded at the County Recorder's Office for each lot to notify future owners of the parcels that they own property in an agricultural area: "This document shall serve as notification that you have purchased land in an agricultural area where you may regularly find farm equipment using local roads; farm equipment causing dust; crop dusting and spraying occurring regularly; burning associated with agricultural activities;noise associated with farm equipment and aerial crop dusting and certain animals and flies may exist on surrounding properties. This statement is, again, notification that this is part of the agricultural way of life in the open space areas of Contra Costa County and you should be fully aware of this at the time of purchase." Grading and Dust Control 12. Comply with the following construction, noise, dust and litter control requirements: A. Noise generating construction activities, including such things as power generators, shall be limited to the hours of 7:30 A.M. to 5:00 P.M., Monday through Friday, and shall be prohibited on State and Federal holidays. The restrictions on allowed working days may be modified on prior written approval by the Zoning Administrator. B. The project sponsor shall require their contractors and subcontractors to fit all internal combustion engines with mufflers which are in good condition and shall locate stationary noise-generating equipment such as air compressors and concrete pumpers as far away from existing residences as possible. C. At least one week prior to commencement of grading, the applicant shall post the site and mail to the owners of property-within 1 ,000 feet of the exterior boundary of the project site notice that construction work will commence. The notice shall include a list of contact persons with name, title, phone number and area of responsibility. The person responsible for maintaining the list shall be included. The list shall be kept current at all times and shall consist of persons with authority to indicate and implement corrective action in their area of responsibility. The names of the individual responsible for noise and litter control shall be expressly identified in the notice. The notice shall be reissued with each phase of major grading activity. 5 A copy of the notice shall be concurrently transmitted to the community Development Department. The notice shall be accompanied by a.list of the names and addresses of the property owners noticed, and a map identifying the area noticed. D. A dust and litter control program shall be submitted for the review and approval of the Zoning Administrator. Any violation of the approved program or applicable ordinances shall require an immediate work stoppage. Construction work shall not be allowed to resume until, if necessary, an appropriate construction bond has been posted. E. The applicant shall make a good-faith effort to avoid interference with existing neighborhood traffic flows. Prior to issuance of building permits, the proposed roads serving this development shall be constructed to provide access to each lot. This shall include provision for an on-site area in which to park earth moving equipment. 13. At least 30 days prior to filing the Final Map or issuance of grading permits, the applicant shall submit a detailed grading plan for the review and approval of the Zoning Administrator. Prior to issuance of grading permits, the applicant shall have had received the Reclamation District #799 permit. TDM Plan 14. Prior to the issuance of building permits, the applicant shall submit a detailed TDM-Plan for review and approval by the Zoning Administrator (unless otherwise required by a TDM Ordinance). The approved TDM Plan shall be operative prior to final inspection by the Building Inspection Department. Indemnification 15. Pursuant to Government Code Section 66474.9,the applicant (including the subdivider or any agent thereof) shall defend, indemnify, and hold harmless the Contra Costa County Community Development Department and its agents, officers, and employees from any claim, action or proceeding against the agency (the County) or agents, officers or employees to attack, set aside, void, or annul the agency's approval concerning this subdivision map application, which action is brought within the time period provided for in Section 66499.37. The County will promptly notify the subdivider of any such claim, action, or proceedings incorporate fully in the defense. Development Guides 16. A guide for development and use provisions for this site shall be as follows: A. On the lots with widths of less than 80 feet, setbacks of residential units shall be varied between 17'/2 and 20 feet. All garages shall have a setback of at least 17 Y2 feet provided vertical garage doors are used. Frontyard setbacks may be reduced to 15 feet for covered porches. The sideyard minimum shall 6 be 5-feet with a total aggregate sideyard. of at least 10-feet. Rearyard minimum shall be 15-feet. Height limit shall be 30-feet .with a two-story maximum. The R-6 zoning district shall be used as a guide for the height, or lot coverage of the site as well as the location of any detached sheds or outbuildings. B. The setback for residential units on lots wider than 80 feet shall be varied between 20 and 25 feet. All garages shall have a setback of at least 20-feet. Frontyard setbacks may be reduced to 15-feet for covered porches. Sideyard minimum shall be 10-feet with an aggregate sideyard of at least 20-feet. The rearyard minimum shall be 15-feet. Building height limits shall be 30-feet with a two-story maximum. The R-10 zoning district,shall be used as a guide for the height or lot coverage of the site as well as the location of any detached sheds or outbuildings. C. Prior to the issuance of building permits on any phase of this site, the applicant shall submit samples of color and exterior materials for the review and approval of the Zoning Administrator. The fences between lots shall be of solid wood and shall be at least 5-feet high. Rearyard fences shall be 6-feet tall and solid wood. Any fencing along a street shall be 6-feet tall solid wood with cement pilastered every 16-feet. The residences of this development shall be finished in a suitable color that shall be complimentary to each other. Residences located on corner lots shall be single story as often as possible. D. At least 15 days prior to issuance of building permits on any phase of this development, a detailed plan showing the location of homes shall be submitted for the Zoning Administrator's administrative review and approval. 17. A homeowners association shall be formed for the maintenance of the small parks and tot lot areas. This shall be accomplished unless a public agency assume the responsibility for the maintenance of these facilities. The means of maintaining parks and open space areas shall.be developed and approved prior to recording the final map for Phase 1 . 18. The garage area of each residence shall be wired for electric car recharging subject to the review and approval of the Zoning Administrator, and subject to the adoption of final Board policy. 19. ' Minimum setbacks along arterial roadways will be at least 200 feet and 100 feet from the centerline of the roadway to the exterior wall of any living space along collectors streets (Cypress Road extension). Utilities - Schools' 20. Prior to recording the Final Map for Phase 1 of this development will serve letters from the Oakley Elementary School District and the Liberty Union High School District shall be submitted to the Community Development Department. 7 21 . Sewage service shall be provided by the Ironhouse Sanitary District. Domestic water service shall be provided by the Oakley Water District. The applicant shall annex to _. these districts prior to recording the final map for Phase 1 . 22. Prior to the recording the final map for Phase 1 , the applicant shall submit a letter from the local transit agency outlining locations of bus stops for the site. The bus stop shall consist of a proper pull out for the bus along the street as well- as a bench and/or covered areas if required by the local transit agency. The bus stops shall be constructed during the various phases of this project as it is developed. 23. The applicant and the Oakley School District are encouraged to enter into a short term funding agreement prior to recordation of the subdivision map for Phase 1 . The agreement could ensure that matching funds are provided for the completion of construction documents necessary for the District's application for State funding. The amount of short term funding would be credited to the applicant's full school impact fees which are paid upon issuance of building permits. The school site shall be acceptable to the Oakley School District. Child Care 24. Provision of a child care facility shall be required for this development. The child care program shall be submitted for the review and approval of the Zoning Administrator prior to filing the Final Map for Phase 1 . If possible, it is encouraged that the child care center be developed and constructed prior to occupancy of residences for Phase 3 of this development. ....:.. .... ::................................. . . . ... ... . t s :::: e: a >::; r: ;:: i#i wJ I < . ; .:>.,:v:: r Th.:::.; .:::Y:<ca.:;e.;#ac....tY:.;:.:: .:;: e:;mo.;:;ed.:a..w....a.::::f..:am.:t.he:la.ke';a :[1' ' ............:.................... .......:::::::::: ..::::: ::y;; ... . orated.:... .t e.a ea.0 the propv5ed school site yr another Jocat on, .6rt.s�te�.;aeceptabfe g Admtn�strato afte fi a1�ixJeve apme t p an approval. Fees 25. The project will pay in-lieu affordable housing fee equal to $''� :$.3:3`33; per residential unit. The fee shall be paid at the time of the issuance of building permits for the various phases of this project. As an alterative to the fees, the project applicant may construct a portion or portion of all of the affordable housing units on site. If this alternative mitigation is selected, the location design of the affordable housing units shall be submitted to the County Zoning Administrator for review and approval prior to filing a final.subdivision map for that phase of the development. 26. When established by the Board of Supervisors, a protection fee shall be paid for each residential unit within the project to acquire development rights on agricultural land and/or open space or wetland areas. The fee shall be determined by the County and paid upon issuance of building permits for 'the various phases of this project. The - ..... maxisri�:trai fee:shall b'e<52.5 D.O:> er>:home>;sub ect:>to>a>co:st ofJi�iri a:d'u' rt:> p. 1:::: ..:: .:: : ::::.: :. g :::.J .sirne:: ,: 27. The project will pay an in-lieu contribution to the County Homeless Trust Fund. The amount of the contribution will be determined by the County and paid, pro rata upon the issuance of building permits for the various phases of this project. 8 Neighboring Properties 28. Prior to recording the map for Phase 1 , the development shall be redesigned so that Cypress Road avoids the Coleman property. The Coleman property shall have suitable access to Cypress Road or to another public road nearby. 29. Prior to recording the final map for Phase 1 , the applicant shall attempt to adjust the lot lines for the Dannelley and Ogrin properties so that they will front on Cypress Lakes Drive. If the Dannelley's and Ogrin's are agreeable, the applicant shall build them a 10- foot paved driveway to their garage areas. If the Dannelley's and Ogrin's are not agreeable to this, then their lots may remain as is with the access road to their property as is unless amended in the future by action of a public agency. 30. Prior to recording the final map for Phase 1 , the Dannelley, Ogrin and Coleman properties perimeters with this site'shall be properly fenced with a 6-foot tall cyclone fence with slats and gates as needed. Alternative fence could be a solid wood fence 6 feet tall. Wetlands - Lakes 31 . The project applicant shall prepare a final wetlands habitat mitigation monitoring program.. The wetlands mitigation monitoring program shall be reviewed and commented upon it adequacy by the State Department of Fish & Game prior to the review of the County Zoning Administrator. 32. Channel crossings underneath the various roads on the site shall be designed so that water fowl and other small animals can cross underneath the road through a suitable pipe structure subject to the review and approval of the California Department of Fish & Game and the County Zoning Administrator. 33. The detailed channel enhancement plan shall be based on the draft channel enhance- ment plan. The plan shall be submitted to Contra Costa County, the California Department of Fish & Game for review and approval prior to approval of the project's final subdivision map for Phase 1 . 34. The design of road crossings, bridges, and/or culverts to replace along the primary drainage channel shall be submitted for the review and approval of the Contra Costa County Department of Public Works and the California Department of Fish & Game prior to filing a final map for Phase 1 of this subdivision. 35. A final channel lake operation and maintenance plan shall be submitted for the review and approval of the County and the California Department of Fish & Game prior to recording the final map for Phase 1 . The plan shall be based on the applicant's proposed lake channel management plans and utilizing plants, flushing, errations, and other technics to maintain water quality without chemicals. 9 ' 36. The project shall comply with all requirements of the County's NPDES permit requirements. The project applicant shall provide the, County with the appropriate documentation regarding compliance with the NPDES requirements prior to the issuance of grading permits for this project. 37. Prior to recording the final map on Phase 1 , the design for the community park shall be submitted to the Zoning Administrator for his review and approval. The parking area shall be located as much as possible away from the Ogrin and Dannelley residences and shall generally be located near the intersection of Cypress Road and Cypress Lakes Drive. Drought tolerant landscaping shall be used as much as possible. 38. The Contra Costa Mosquito Abatement District shall be provided the final design plans for the wetland mitigation areas, golf course and lake plan for their review and comment prior to their approval by the Contra Costa County. Golf Course 39. Prior to the development of the golf course on the site, a landscape plan for the golf course shall be submitted for the review and approval of the County Zoning Administrator. The plan shall be accompanied by a landscape maintenance plan outlining how the maintenance of the golf course can be accomplished with an environmentally sensitive and organic maintenance plan as possible. 40. A final maintenance plan for the golf course shall be submitted for the review and approval of the County prior to filing the final subdivision map for Phase 4. The final maintenance plan shall build on the maintenance criteria established in the project plans and identified standard maintenance and management practices to be carried out on the golf course. Specific maintenance procedures shall be identified regarding the use of pesticides, herbicides and fertilizers and these shall be kept to a minimum. An emphasis of the maintenance plan should be to reduce any potential leaching of materials into the local ground water resources. The maintenance and management plan shall also outline specific irrigation practices designed to reduce water consump- tion. 41 . A ground water management plan to address water requirements for irrigating the golf course and parks shall be developed. The ground water management plan shall also address the management of pesticides and measures to be taken to reduce potential impacts on ground water resources. The plan shall identify what areas, and in what sequence water will be discontinued to portions of the golf course and park in the event of water cut-backs because of drought or substantial lowering of the water table. The plan shall be approved by Contra Costa County prior to filing the final subdivision map for Phase 4 of this development. 42. The golf course shall be designed to use grasses that are drought-tolerant to limit the needed amount of water for irrigation. ' ' 10 ` Levees ' 43. Fneved fui;thei: bael( an hall be-MOFe eaFefully designed se that it will have a ew lan for the aFea east of the Read ...~.---.. .h— developer pe . levee a|onQ'Sandnnnund Boulevard inthe+aF*efor review and administrative approval of the Zoning Administrator prior to construction of the levee. 44. The design of the project levee shall be in accordance with. the standards and requirements of the Federal Ennor0onoy Management Agency for anurban standard levee. Provision ShnU badesigned into the project levee to allow for a future increase in height of 4'feett0 8Uovv for the pOaSib|8 greenhouse effect. During the design of the project|eve8' thgoroS1e|ev8tiUnehaUbeinonaosedbyan8rn0untequive\9nttoth8 projected long term settlement. Levee design shall be acceptable to Reclamation District #799. Levee and drainage systems shall b8dedicated t0Reclamation District #798. 45. The side S\npeS'ofthe project |avaeahaUb8p\an1ndandirrigatedtonuduooeroSnmand provide dust control inaccordance with limitations imposed by FEMA. 46. Adequate easements shall be granted to the maintenance authority in order to provide for maintenance and upgrading of the levee and to prohibit encroachments onto the levee. 47. To minimize the risk of liquefaction beneath the primary levee, the loose clean and silty Sand to depth of 10 to 15featorwhatever depth is required shall be reworked and densifi8d. Over-excavation rather than deep dynamic compaction shall beused for the compaction of. the soils in these o/aao. 48. Adetai|ed emergency evacuation plan based on the project's proposed emergency evacuation plan shall be prepared incooperation with Reclamation.District #799 prior to approval of Phase 1 of the project's subdivision map. Evacuation plan shall include at amin\Vlurn the following measures: A. Criteria for determining when enemergency exists. B. Methods for notifying and evacuating area residences. C. Identification Vfagencies and individuals responsible for 8nn8rQ8nCy response an'/ public evacuation. D. Plans for returning evacuates to their hOrn8 after an emergency has passed. Any construction of facilities required by the evacuation plan shall be constructed prior to levee construction. 11 :.,........;..:: puat►vn Plan shall:be.subject to the rev►eust o#.the Publ►c Worcs.Departmenf::and: t...B reviBvu and apprd vai c�,f l3eclamatro0 t 799: and..che. on�n Adrr►�n�stratc�r ...... Th"e>P:last s:f OfF der:t f: 'E: >the''�','u `rrient ari' >#`." ...., > �<: :.>:: <: :.:.:.y....). q p d. aedl►t►es ecessary to.prov►de safe access fi:>: ::>r::: c :`:2. .:: fi e.:.p::A. .::t..:::::);:t:.:8.:entlt :<:res: :o:n. ►:..:: :::>:;Qr:.<:: .rraw::d;n. Ss;:tf�><th.e.<::: :rt: j.:::.::::::::::::::::::::::::::.:.:......:.::::....:::p...............:..........:::P.:::::::::::::::.:.$ :::.:.,.,...........p........:....,::e::::d. 3; .......... ....:;.....: ` is ':<.;<,:,,;::,:;:i',: ;; ':<:;.;.,: : >:;:f(::;: : ;,, :;: it >;< ::;2::::;?:.::: :.;;:;.,, tm►ng ctf when the:equ►pment and fad l►t►es are needed.:to praufde safe access lI p.t e p.olact �n the:,event: nf.an emergency;. The,Plan shall be dastgned to prqu�de. g dt y ccess once the flood waters have been stab►t,zed ar}d�confmue::td�prav►de u 1... h ..l 16.0......,CC...........:.:.:::t.::::t.:::e..:.e...ee b..ea......s...a .a...ed..a....d..:..Harmal;aCc'ess<s: testo:recl' .... . he.e... ba .o::.:.eed:tv provide for emergend:y:.:accass.:w136n there: �S a::permri8r}t :.:.;:.: food p ctected accEss prov►ded on Cypress Road between Jersey Island Rgad and t#1.e ..rO BC... 49. Prior to recording the map for Phase 1 of this development or prior to issuance of grading permits, a final ground water monitoring plan shall be submitted for the review and approval of the Reclamation District #799 and Contra Costa County prior to filing a final subdivision map. A completion bond shall be provided that will provide Reclamation District #799 with protection for its existing levee and drainage systems. 50. The project's site shall continue to be a part of Reclamation District 799 and shall be prohibited from succeeding from this district, even if removed from the flood hazard zone, by the proposed internal levee system, to provide the district with continue long term sources of funding for maintenance of the existing Reclamation District 799 levee system. 51 . Maintenance of the landscaped strip on the side of the levees will be done by the homeowners association or a special district. It will not be the responsibility of the agency that maintains the project levees. The landscape strip around the outside of the levee shall be at least 10-feet wide. This strip may be eliminated in areas where the levee may cross under Bethel Island Road. Levee landscape guidelines shall be finalized once the public agency responsible for maintaining the levee is determined. The levee landscape guidelines should then be submitted to the public agency responsible for maintenance of the levee for review and approval prior to installation of landscaping on the levees. Recreation Maintenance 52. The landscape maintenance district, or other funding source consisting of the property owners within the project site, shall be established for the proposed project to pay for long term maintenance of public recreational areas within the site. The project applicant shall submit a proposal for the landscape maintenance district to the County for approval prior to recording the final map for Phase 1 of this development. 12 Construction Parking 53. Prior to construction of any phase of this site, an on-site parking area shall be developed for parking needs of construction crew members. This plan shall be submitted to the Zoning Administrator for review and approval prior to construction of residences within the various phases of this development. CC & Rs 54. The CC & Rs shall contain information regarding the use of or disposable of undesirable materials such as motor oil, paints, garden pesticides and other household products. 55. Prior to recording the final map for Phase 1 , a street sweeping program shall be provided to reduce urban pollution run-off into the proposed lakes and channels. The street sweeping may be provided by the County through its existing street sweeping program or if this is not feasible alternative measures could include funding of the street sweeping program by the homeowners association. The CC & Rs of the development shall be acceptable to Reclamation District #799. Soils - Geology 56. The project shall be required to adhere to the approaches outlined in the Kleinfelder report analyzing the approaches for mitigating liquefaction impacts. The specific approach will depend on site specific conditions and analysis. The project applicant shall follow the review and approve recommendations of the Kleinfelder report. The report documenting the methods used in the field to reduce liquefaction potential shall be submitted to the Public Works Department and to the public agency responsible for maintenance of the levee system for their review and approval. An additional geotechnical report outlining means of protecting the new levees without using deep dynamic compaction shall be submitted for review and approval of Reclamation District #799 and Contra Costa County. 57. At least 45 days prior to recording a final map for Phase 1 or any phase, issuance of grading permits, or installation of improvements or utilities, submit a preliminary geologic, soils, and foundation report meeting the requirements of the Subdivision Ordinance Section 94-4.420 for review and approval of the County Zoning Administra- tor. Improvement, grading and building plans shall carry out the recommendations of the approved report. 58. The report required above shall include evaluation of the potential for liquefaction and seismic settlement. 59. Record a statement to run•with deeds to the property acknowledging the approved report by title, author (firm), and date, calling attention to approved recommendations, and noting that the report is available from the seller. 13 60. At least 45 days prior to issuance of permits to grade and create the lake and channels on the site, a suitable geotechnical report shall be submitted .for the review and approval of the Zoning Administrator detailing means to stabilize the lake bank in case of earthquake and to reduce the possibility of liquefaction of this area. 61 . The ground settlement monitoring plan shall be finalized and submitted to the Reclamation District #799 and 'Contra Costa County for review and approval prior to beginning any construction or dewatering activities on the site. Plan shall identify the location of all monitoring wells, and provide specific on well completion and methods and frequency of monitoring. Plan shall identify settlement plates as well as contingency plans to control subsidence or mitigate subsidence and related damage. 62. Ground water monitoring plans to provide early detection of changes in ground water level and to allow adjustment in the construction techniques if necessary shall be developed. Monitoring wells and settlement plates shall be placed on the project's site and surrounding properties to control ground water levels. The ground water monitoring plan shall be acceptable to Reclamation District #799 and Contra Costa County. 63. The project owner shall fund an independent geotechnical and drainage engineering review of the project design and construction on behalf of Reclamation District #799. This review shall show the impact and a plan to alleviate the impact of the project on existing drainage pumps and systems. The report shall be acceptable to Reclamation District #799 and Contra Costa County. 64. The project grading plan shall include the following mitigation measures: A. The name and phone number of a designated dust control coordinated will be posted at the construction site. The dust control coordinator will respond to complaints by suspending dust-producing activities or providing additional personnel or equipment for dust control. B. The contractor will implement the following measures. 1} Suspend earthmoving or other dust-producing activities during periods of high winds; 2) Provide equipment and personnel as necessary for watering of all exposed or disturbed soil surfaces. An appropriate dust suppressant, added to water before application, should be utilized; 3) Water or cover stockpiles of debris, soil, sand or other materials that can be blown by the wind; 4) Sweep adjacent streets of all mud and debris, since this material can be pulverized and later resuspended by vehicle traffic; 14 5) Water, seed, cover or apply dust suppressants to completed cuts or graded areas as soon as grading activities cease; 6) In addition to the dust control measures proposed as part of the project, the project applicant should post the name and phone number (business and non-business hours) for the dust control coordinator along the perimeter of each construction site and provide this information by mail to residents within 1 ,000 feet of the area of construction; 7) Earthmoving and other dust-producing activities should be suspended when watering and other dust control measures are unable to eliminate visible dust plumes. Fire Station 65. The proposed new fire station on the project site shall be operational prior to the occupancy of the first homes on the site. The fire station shall meet all applicable requirements of the appropriate fire district (Oakley Fire Protection District or Bethel Island Fire Protection District or their successor). If necessary, a special district fee may be required to augment and provide adequate funding to fully staff the new station. 66. Prior to recording the parcel map for Phase 1 , the site shall have been annexed into either the Bethel Island Fire Protection District or the Oakley Fire Protection District or their successor. Landscaping 67. Prior to construction of the various residences on this site, landscaping plans for frontyard landscaping of the residences shall be submitted to the Zoning Administrator for review and approval. The landscaping plan shall include an alternative landscaping with xeriseape landscaping for builder installed frontyards. Landscaping of frontyard areas of this site shall be installed prior to occupancy of residences. 68. Comply with the landscape requirements as follows; following reports are subject to the Zoning Administrator review and approval. Landscaping shall conform to the County's Water Conservation policies in regards to the use of drought-tolerant trees, bushes and ground cover. . At least 30 days prior to requesting recording of the final map for Phase 1 , submit a street tree planting plan for entire development, a landscape being planned for landscaping along the site's frontage on Cypress Road extension and Bethel Island Road, and portions of the site fronting on Sandmound Boulevard. The landscape plan shall include typical frontyard landscaping plans for residences on the site. Prior to recording the final map for Phase 1 of this development, submit a detailed trails plan indicating location of trails, their design, and their maintenance on the site. Because of high water •table-areas around the lake and channels may be landscaped with native willows, a new native cottonwoods and California natives suitable for the area. Trees may be 5 gallon size, bushes 1 gallon size. 15 69. Prior to recording the final map for Phase 1 of this development, the design of the street lights shall be submitted for the review and approval of the County Public Works Department and the County Zoning Administrator. The street lights shall use down focus lights to eliminate to reduce glare to the surrounding area. Archaeological 70. Should archaeological materials be uncovered during grading,trenching or other on-site excavation(s), earthwork within 30 yards of these materials shall be stopped until a professional archaeologist who is certified by the Society for California Archaeology (SCA) and/or the Society of Professional Archaeology (SOPA) has had an opportunity to evaluate the significance of the find and suggest appropriate mitigation(s), if deemed necessary. 71 . Any development within the western perimeter of the site within the archaeological sensitive area shall be done in a manner which reduces ground disturbance to an absolute minimum. The construction activity in this area shall be closely monitored by an on-site archaeologist during any development in these areas. Rubber tired construction vehicles shall be used throughout the site and excavation for landscaping irrigation shall be allowed in fill materials only. Should it be necessary to excavate through native soils an archaeologist shall be present to monitor soil removal to determine if there are any cultural materials. 72. Prior to construction of the proposed fire station, a detailed archaeological reconnais- sance of the area shall be done to determine if the station can be built as proposed. If it should be shown that it cannot be as proposed, then the station shall be moved to an area of lower archaeological sensitivity. This shall be accomplished prior to recording the parcel map for Phase 1 of this development. 73. Lot #10 in Neighborhood 1 shall be removed or redrawn in a manner that it avoids the archaeological sensitive areas. Lot #11 in Neighborhood 1 shall be removed or redrawn in order to avoid archaeological sensitive areas. 74. The rear lot lines of Lots #29 and #30 in Neighborhood 7 shall be redrawn in a manner that avoid archaeological sensitive areas. 75. An archaeological monitor shall be present when grading, excavation, trenching or other soils disrupting activities are carried out in any of the mapped archaeological sensitive areas. An archaeological monitor shall be on-called when grading, excavation, trenching or other soils disrupting activities are carried out in the project's site. In the event that a prehistoric site, burial or historical resources are encountered during construction of the project, the project engineer will be obligated to temporary stop the relocate construction activities and notify the archaeological monitor immediately. In the event of a significant prehistoric or historic resources are identified, no further construction shall be permitted in that location until a mitigation plan can be formulated and implemented. 16 76. In the event that human remains are discovered during construction, excavation shall be halted at that location. Any finds of human remains must be reported to the Contra Costa County Coroner's Office. In the event that the find is determined to be prehistoric,the Native American Heritage Commission must be notified within 24-hours to alert them of the find and to permit the designation of a native american representa- tive. Consultation between the archaeological consultants in charge of monitoring, Contra Costa County and the Native American representative would then determine the course of action to be taken with the burial in .question. Ideally, if removal is undertaken time should be allowed for the study of the remains in an associated grave prior to their return to the Native American community for reburial at a location of their selection. 77. The report of findings and analysis of all archaeological data recovered during testing, excavation, monitoring and any mitigation procedures are taken should be prepared by a qualified archaeologist for submittal to Contra Costa County, and proper State agencies. 78. An acceptable (to the County) plan shall be developed for informing construction personnel on the potential for discovering of cultural or human remains, and the need for proper and timely reporting of such finds and the consequences of failure thereof. The plan shall be developed and approved prior to issuance of grading permits. 79. Prior to recording the final map for Phase 1 of this development or the issuance of ahy grading permits, an agreement shall be reached with the Native American Heritage Commission (NACH) in Sacramento regarding potential Native American concerns, values and traditional use areas relative to the proposed project site and vicinity. The agreement would specify when, in the event of a discovery, Native American involvement would occur, and the treatment and ultimate disposition of any ancestral remains. 80. The proposed intersection and improvements of the project's entrance and Bethel Island Road shall be realigned to the north as much as possible to avoid impacting cultural resource sites. 81 . The alignment of any future extension of Bethel Island Road south of Cypress Road shall be, as far east as feasible, to avoid the archaeological site in that area, taking into consideration safety factors. The project levee along the westerly side may have to be moved up to 50 feet east. . 82. Prior to recording the final map for the various phases of this project, a soils sampling shall be conducted in those areas of the site where heavy equipment has been stored, repaired facilities, or located where above or below ground storage tanks are or we-re located. should contaminated soil be identified, removal and remediation of the material shall occur prior to excavation or construction activities commence in these areas. The Contra Costa County Health Services Department shall supervise and 17 authorize any soil sampling procedures and remediation. Prior to recording the final map for various phases of this development, any existing water wells in that area-or septic tank leach fields shall be properly removed under County Health Department authorization. Road and Drainage 83. The following requirements pertaining to drainage, road, and utility improvements will require the review and approval of the Public Works Department. In accordance with Section 92-2.006 of the County Ordinance Code, this subdivision shall conform to the provisions of the County Subdivision Ordinance (Title 9). Any exceptions therefrom must be specifically listed in this conditional approval statement. A. Install street lights and annex the property to County Service Area L-100 for maintenance of the street lights. The final number and location of the lights shall be determined by the Public Works Department, Transportation Engineer- ing Division. B. Underground all utility distribution facilities, including the existing utilities along the Bethel Island Road and Sandmound Boulevard frontages. The underground- ing of utility distribution facilities does not require undergrounding of the 500 KV PG &E facilities. C. Submit improvement plans prepared by a registered civil engineer, payment of review and inspection fees, and security for all improvements required by the Ordinance Code or the conditions of approval for this subdivision. These plans shall include any necessary traffic signage and striping plans for review by the Public Works Department, Transportation Engineering Division. DRAINAGE IMPROVEMENTS D. Convey all storm waters entering or originating within the subject property (including the outside slopes of the levee), without diversion and within an adequate storm drainage facility, to an adequate, publicly maintained pump station. The pump station location and design shall be subject to the review of the Public Works Department, and the review, approval and acceptance by Reclamation District 799. E. The Ordinance Code prohibits discharge of storm waters to roadside ditches. However, as roadside ditches are characteristic of the,area, an exception from this requirement is granted provided the applicant verifies the adequacy of the downstream ditch system and constructs any-necessary improvements to make this 'system adequate to a point where the flow will be accepted by Reclama- tion District 799. F. The Ordinance prohibits discharging storm waters into the Contra Costa.Canal or any other water conveyance or impounding facility for domestic water consumption. 18 G. Install, within appropriate drainage easements, any portion of the drainage system which conveys run-off from public streets. H. The applicant shall submit a lake management plan for review by the Public Works Department, Reclamation District 799, the Health Department and the review and approval of the Zoning Administrator. The lake management plan shall provide for control of a stable lake level, control of bank erosion due to wave action, control of aquatic plants and algae, desiltation, control of chemicals used within the project, including those used for lake maintenance, households and the golf course. The applicant shall include language in the Covenants, Conditions and Restrictions governing use of household chemicals. The plan shall include a plan for compliance with the NPDES.. I. Prior to the filing of the first final map the applicant shall provide the Public Works Department with a feasibility study of the proposed drainage system including the proposed detention basin. The study shall address the potential maintenance cost of the system and the reliability of the system taking potential groundwater infiltration and pump failure into account. Other items to consider include: pump failure, lake detention capacity due to water table fluctuation, accelerated siltation of the system due to low.velocities, stagnate water, mosquito abatement, odors, and plant and algae growth. Should the maintenance costs exceed the norm in the County, a public entity such as Reclamation District 799 shall provide for perpetual maintenance of the underground drainage facilities. If Reclamation District 799 will not accept the underground storm drain system for maintenance, the on site roads and drainage shall be private facilities, and privately maintained. Any detention basin, however, must be maintained by a public entity as required by Ordinance Code. Improvements not to be accepted by Reclamation District 799 shall be subject to the review and approval of the Public Works Department. This study shall be subject to the review of the Public Works Department, Reclamation District 799 and the review and approval of-the Zoning Administrator. . J. Prior to filing of the first final map the applicant shall provide a list of which facilities are proposed to be maintained by which public entity, or by a private entity. The list shall be subject to the review of the Public Works Department, Engineering Services Division, Reclamation District 799 and the review and approval of the Zoning Administrator. K. Prevent storm drainage, originating -on the property and conveyed in a concentrated manner, from draining across the sidewalks and driveways. LEVEES - L. The proposed levee system shall be constructed to FEMA, U.S. Army Corps of Engineers, Reclamation District 799 and County standards subject to the review and approval of Reclamation District 799. The trails and other associated planning issues shall be subject to the review and approval of the Zoning 19 Administrator. If Reclamation District 799 does not accept the levee for maintenance, it shall be maintained by another public entity subject to the review and approval of the Zoning Administrator. M. Landscaping of the levees shall be subject to the review of FEMA, Reclamation District 799, and the entity which will accept the levee for maintenance, and the review and approval of the Zoning Administrator. N. The applicant shall submit the final groundwater monitoring plan for review by Reclamation District 799 and the review and approval of the Zoning Adminis- trator prior to beginning any construction that requires dewatering to com- mence. O. Observe a 100 foot setback from the centerline of all levees unless a reduction is allowed subject to the review of Reclamation District 799 and the review and approval of the Zoning Administrator. P. Grant land rights to Reclamation District 799 pursuant to the standards and requirements of Reclamation District 799, subject to the review and approval of the Zoning Administrator. RIGHT OF WAY.DEDICATIONS Q. Convey to the County, by Offer of Dedication, additional right of way along the project frontage of Bethel Island Road (north of Cypress Road) as required for the planned future half-width of 65 feet. The right of way shall provide for ultimate dual left turn lanes at the Cypress Road-Bethel Island Road intersec- tion. R. Convey to the County, by Offer of Dedication, additional right of way along the project frontage of Sandmound Boulevard as required for the planned future half-width of 45 feet. The right of way shall widen at the Bethel Island Road intersection to provide for a left turn lane from westbound Sandmound Boulevard traffic to southbound Bethel Island Road. S. Convey to the County, by Offer of Dedication, 55 feet of right of way for the planned future road along the westerly property line south of Cypress Road. This 55 feet of right of way will be the easterly half width of a 110 foot right of way for the ultimate extension of Bethel Island Road southerly to Rock Slough. The westerly 55 feet of right of way will be acquired with the development to the south or west of this project. The right of way dedicated shall widen to a 60 foot half-width within 300 feet of the intersection of Cypress Road. The,alignment shall be to arterial standards, and subject to the review the Public Works Department and the review and approval of the Zoning Administrator. T. Relinquish abutter's rights of access along all proposed public arterial and major collector roads with the exception of access points approved with this project. 20 ON-SITE ROADWAY IMPROVEMENTS U. Construct the on-site public roads to County public road standards, and convey to the County, by Offer of Dedication, the corresponding right of way. Roads which shall be private roads shall be constructed to County private road standards, subject to the review of the Public Works Department, Engineering Services Division, and the review and approval of the Zoning Administrator. V. On all public roads with longitudinal slopes of eight percent or less, all public pedestrian access ways shall be designed in accordance with Title 24 (Handicap access). This shall include all driveway depressions as well as handicap ramps. W. Construct a new three leg intersection at Cypress Road and Bethel Island Road, and adequate approaches to this intersection. The improvements shall provide for two through lanes along each leg in each direction, and shall extend 1 ,000 feet along each of the three legs of the intersection. The intersection shall have the turn lane requirements shown in Figure 3.2-13 of the DEIR. This intersec- tion shall be designed so that it will ultimately be consistent with a future extension to Byron Highway south of the intersection, and any realignment of Cypress Road to a location north of the existing Cypress Road roadway and above the flood plain. The 1 ,000 foot section of Cypress Road shall also be realigned north of the existing Cypress Road roadway and above the floodplain to match the proposed improvements to Subdivision 7588. The final design of the vertical curvature of Cypress Road where it crosses the levee shall be approved prior to filing of the first final map. Traffic signals shall be installed at this intersection and put into operation prior to issuance of the 500th building permit, or sooner if needed. The need for the signal shall be analyzed by the Public Works Department prior to filing the final map for each phase, and installed if needed, prior to issuance of the 500th building permit. The Zoning Administrator will consider, subject-to the review of the Public Works Department, Engineering Services Division, allowing construction of an interim configuration of the intersection if it can be shown to operate in a safe and efficient manner. The applicant will be required to submit a conceptual plan for the interim and ultimate intersection configuration subject to the review of the Public Works Department, Engineering Services Division, and the review and approval of the Zoning Administrator. In any event, the applicant shall construct the ultimate intersection improvements prior to issuance of the 500th building permit. The location of the Cypress Road-Bethel Island Road intersection shall be sub).ect to the review of the Public Works Department, Transportation Engineering Division, and the review and approval of the Zoning Administrator. ' 21 ` -_- ' X. The following design speeds shall beused for the design ofthe levee crossings ofpublic roads, and the design ofoff-site ruedvvaym� {�ypresoRoad axton/�on: 45K4PHfor the xvester(yorb�yihg' and 35K4P�fforthe easterly crossing. The north-south collector: 35 MPH for both the north and south crossing. 3ondrnOundBoulevard: 4! MPH. Bethel Island Road and the off-site portion of Cypress Road: 60 MPH. Y. The following design speeds shall be used for the internal road oymtann: 45 MPH for Cypress Road between the westerly levee crossing and Cypress Lakes Drive, 35 MPH for Cypress Road between Cypress Lakes Drive and Sandmound Boulevard, 35 MPH on the north-south collector between Sandmound Boulevard and the southerly property line. Z. Construct rood improvements along the frontage of the Cypress Road extension. a. Construct necessary longitudinal and transverse drainage (longitudinal drainage may be in open drainage ditches), and necessary pavement widening o|VnQ the frnntmgeS will satisfy this requirement. The rnininnurn povornontha\fvvidlh shall be 20 feet. Aten foot recovery area shall be required between the edge of pavement and the top of bank of the drainage ditch. Prior to issuance of the 150th building perrnit, construct the extension 0fCypress Road from Bethel Island Road tnSandrnuund Boulevard tOo rninirnunn width Of 28-feet at ultimate line and grade. AA. phVr 10 issuance of the 1 000t building permit, construct the proposed north- south Orth- mouthcoUectmxbetvv8en Cypress Road and 3andrnound Boulevard toprovide maconoa/yaccass. ' AB' Construct turn lanes and tapers on Cypress Rood onthe east side of Cypress Lakes Ohva to Caltrans standards subject tothe review and approval of the 'Public Works Department, Ehginoar\nQ Services Division. AC. Provide o 60-foot wide right-of-way (and necessary slope easements) for a future roadway connection to the property south of Cypress Lakes and construct the road tothe top of the project levee. This roadway connection would be secondary access tothe project to the south. It should be opened for traffic only after Bethel Island Road ioextended south to provide the main access to development of the property to the south. A[>. PrOida deed notification to those parcels that abut the road that is to be extended to the property to the south, and install signage at the end of the road' to inform prospective property Ovvn8r3 that itmay be extended in the future. 22 AE. Provide a signal at the proposed Fire Station subject to the review of the Public Works Department, Engineering Services Division and the_ Fire District. This signal shall be in operation prior to occupancy of the fire station. This signal shall be interconnected to the signal at the intersection of Cypress Road and Bethel Island Road. AF. The entrance to the public park containing the ball fields shall be a street-type connection with 20-foot radius curb returns. AG. All trail and golf cart crossings of public roads shall be designed for proper . stopping sight distance and signed subject to the review and approval of the Public Works Department, Engineering services Division. AH. On road bicycle paths shall be provided as shown in Figure 3.9-3 of the DEIR. The required collector road extension to the southerly property line shall be wide enough to accommodate an on-street bicycle path. Al. The intersections of Maple Court and Willow Court and the intersections of Redwood Court and Ash Court with Park Place Circle are located too close together. The minimum distance between intersections should be 150 feet. AJ. The 1/2 cul-de-sac on Pasa Tiempo Court shall be eliminated or made into a full cul-de-sac. AK. The alignment of the Cypress Road extension to Sandmound Boulevard shall be subject to the review of the Public Works Department, Engineering. Services Division, and the review and approval of the Zoning Administrator. The alignment shall miss the "Not a Part" properties (Coleman, Ogren, Dannelley properties) within the project lit-nits, or they shall be purchased in whole or in part by the applicant. AL. Construct a separated bicycle/pedestrian facility along the frontage of Bethel Island Road. This facility may be located on top of the levee provided all approving agencies allow the placement of a trail facility on top of the levee. Access from the trail shall be provided to the intersection of Bethel Island Road and Sandmound Boulevard and at the at grade crossings of all public roads. Provide an easement at the southwest corner of the project for a future access from the levee trail to the southerly extension of Bethel Island Road. These access points shall conform to the requirements of the Americans with Disabilities Act. LANDSCAPING - AM. Install permanent landscaping and automatic irrigation facilities within the parkway and median areas, and install interim landscaping features within the future road areas, if any. All work shall be done in accordance with the guidelines and standards of the County. Funding of, and maintenance of, the 23 new plantings shall be guaranteed by the developer until the expiration of the plant establishment period and, until funds are available through a landscaping district. AN. Apply to the Public Works Department for annexation to the County Landscap- ing District AD 1979-3 (LL-2) for the future maintenance of landscaping and irrigation facilities in median islands, parkways and other areas ("open space" and the levee landscaping is specifically excluded). AO. Submit two sets of landscaping plans and an estimate of improvement costs prepared by a licensed landscape architect to the Public Works Department, and pay the plan review and field inspection fees at least six weeks prior to the filing of the first final map. All landscaping and irrigation facilities shall be maintained by the applicant until funds become available for their maintenance by the County after final inspection is cleared. FRONTAGE IMPROVEMENTS AP. Construct road improvements along the frontage (east half) of Bethel Island Road. a. Constructing necessary longitudinal and transverse drainage(longitudinal drainage may be in open drainage ditches), necessary pavement widening to obtain the ultimate half-width, and the median island (including surface treatment and/or landscaping and automatic irrigation facilities) along the frontage will satisfy this requirement. A ten foot recovery area shall be required between the edge of pavement and the top of bank of the drainage ditch. These improvements shall be constructed prior to the filing of any final map which takes access from Sandmound Boulevard along the northern portion of the property. b. In lieu of constructing the median island (including surface treatment and/or landscaping and automatic irrigation facilities) the applicant shall place a cash deposit in the Road Improvement Trust (Fund No. 819200- 0800) for the future construction of a half width of the median island (including surface treatment and/or landscaping and automatic irrigation facilities) when the other half of Bethel Island Road is improved. AQ. Construct road improvements along the frontage of Sandmound Boulevard along the northern and eastern project boundaries. a. Construct necessary longitudinal and transverse drainage (longitudinal drainage may be in open drainage ditches), and necessary pavement widening along the frontages will satisfy this requirement. The minimum pavement half-width shall be 20 feet. A ten foot recovery area shall be required between the edge of pavement and the top of bank of the drainage ditch. 24 b. The road improvements along the northerly Sandmound Boulevard frontage of this property shall be constructed prior to the filing of any final map which provides access to Sandmound Boulevard along the northerly property line. C. The Sandmound Boulevard road improvements along the eastern property line of this property shall be constructed, prior to the 150th building permit, subject to the review of the Public Works Department, Engineering Services Division, and the review and approval of the Zoning Administrator. OFF-SITE ROADWAY IMPROVEMENTS AR. Construct safety improvements at the Cypress Road - Jersey Island Road intersection if the Public Works Department, Engineering Services Division, finds that they are warranted prior to construction by the developer of Subdivision 7588. A condition of approval will be included in the conditions of approval for Subdivision 7588 which will require the developer of Subdivision 7588 to reimburse the developer of Subdivision 7562 for intersection work which they performed at the Cypress Road - Jersey Island Road intersection. AS. The access to the "Boat & RV Storage & HOA maintenance center" off of Sandmound Boulevard should be a minimum of 26 feet wide (14 foot inbound and 12 foot outbound lanes). The entrance to the access road should provide curb returns of sufficient radius to allow vehicles to enter and exit without blocking both lanes of traffic on Sandmound Boulevard. AT. The applicant shall contribute $25 per unit to the Road Improvement Trust (Fund No. 819200-0800) designated toward the improvement of the State Highway 4 - Cypress Road intersection. The applicant shall perform a traffic signal warrant analysis subject to the review of the Public Works Department, Engineering Services Division, and the 'review and approval of the Zoning Administrator prior to the completion of each phase of this Subdivision which cumulatively creates each additional 500 unit increment in the Bethel Island Bonus Area to determine if improvements are needed at this intersection. The applicant shall construct the required improvements when needed. AU. Contribute $30,000 to the Road Improvement Trust (Fund No. 819200-0800) designated for the Oakley/North Brentwood Area of Benefit as this projects fair share of improvements to the State Route 4/Neroly Road intersection. $30,000 is approximately 10% of the estimated cost of improving this intersection as required-by mitigation measure 3.2-14 of the project EIR. The $30,000 shall be paid in $10,000 increments with the filing of the final maps for the first three phases. 25 AV. Contribute $660 per unit to the Road Improvement Fee Trust (Fund No. 819200-0800) for sub-regional improvements to the Laurel Road Corridor consisting of the applicant's share of construction of the Cypress Road - Laurel` Road connection from State Highway 4 to Machado Lane and for widening Laurel Road from State Highway 4 to the proposed State Route 4 Bypass. AW. GeAtFibute $60 peF unit to the Read iFfiffevement Fee TFUSt(Fund Pie. 81 92()Q a .to issuance of the:1 OOth building permitjr�9th8 Bethel [siatidof# island:bbnus area, Cypress Road between State Route 4 and e. .:.:I :.....:....:::::......:.:.:.:.::::;:.::...:......:::::.:.:..::. Machado Lane to provide two 12-foot lanes with 8-foot paved shoulders. '1'Yt1:7 Feadw ,ent shall be eensTrueted-PrieF to iss ranee-efi the h "`I"'"" ""' sisle Bethel and e,fffiben us�� as aFea.-Reimbursement to the a p p 1 i e a nt develWe.r that constructs this improvement shall come from the plead IMPfeVemen, I=ee-TFust (Fund No.8 -o 19200-0800) as beeeme-ayrrable- Bet el:1sland::Area of Benefit in proportion to the:cast of this:smpr:ayement in the irro: :Ct::l s ;.o:f:;:;t:[te;:;A:r:ea»o.f:.:;;:Bern.e.fit:>5::::bevel:0 m:ent:::T r:a:m;:::R..: .............. AX. The applicant shall contribute $ $1000 per single family unit to the Road Improvement Fee Trust (Fund No. 819200-0800) designated for the Delta Expressway, to be consistent with the Oakley Area of Benefit, if building permits are issued prior to adoption of a new Delta Expressway fee ordinance. If the proposed Delta Expressway fee ordinance is adopted prior to issuance of building permits, the applicant shall instead be responsible for payment of the adopted fee. AY. The Bethel Island Road/Sandmound Boulevard intersection shall be improved and widened, and a left turn lanes shall be constructed. Sandmound Boulevard shall be realigned to a right-angle intersection at Bethel Island Road. The realignment shall allow for the extension of Sandmound Boulevard to the west of Bethel Island Road without conflicting with the drainage channel on the west side of Bethel Island Road. These improvements, plus a traffic signal at Sandmound Boulevard and Bethel Island Road, shall be installed prior to the filing of any final map which provides access to Sandmound Boulevard along the northerly property line. AZ GOnt........ 726 per dwelling unit to t3�e Road frnprovement dee Trust.{ urtd: N a81;92Q008 0 ;;::; «> 0 ) for the extension flf Syron Highway#rorn Delta R:aad to the rife`rSe:c;tton pf Cypr;ess :ftga:d.:..."do".. eti el Bland i5ael; BA. Prior to issuance of the 100th building permit in the Bethel Island off island bonus area, construct pavement widening for left turn channelization at the intersections of Sellers Avenue and Knightsen Avenue with Cypress Road sub'ject to the review of the Public Works Department and the review and approval of the Zoning Administrator. All pavement shall be at ultimate line and grade. 26 BB. Prior to issuance of the 1000th building permit in the Bethel Island off island bonus area, install traffic signals at the Sellers Avenue and Knightsen Avenue intersections with Cypress Road, or sooner if needed. The need for the signals shall be analyzed subject to the review of the Public Works Department, and the review and approval of the Zoning Administrator, prior to filing the final map for each phase, and installed if needed, prior to issuance of the 1000th building permit. BC. Prior to issuance of the 1000th building permit in the Bethel Island off island bonus area widen Cypress Road between Machado Lane and 1000 feet east of Knightsen Avenue to a four lane arterial with median island. -The alignment and geometrics shall be subject to the review of the Public Works Department, Engineering Services Division, and the review and approval of the Zoning Administrator. BD. The applicant shall perform a survey of the pavement condition on Cypress Road between State Route 4 and Bethel Island Road prior to the commence- ment of any work on site, and after completion of each phase. The surveys shall be subject to the review and approval of the Public Works Department. The applicant shall perform any necessary remedial work to the surveyed portion of Cypress Road prior to the filing of the final map for the next phase; subject to the review of the Public Works Department and the review and approval of the Zoning Administrator. BE. Submit a sketch plan to the Public Works Department, Transportation Engineering Division, for review showing all off-site public road improvements prior to starting work on the improvement plans. This shall include the improvements at the Cypress Road - Bethel Island Road intersection, the Cypress Road extension through the project and the construction of Sand- mound Boulevard along the northerly and easterly boundaries of this project. The sketch alignment plan shall be to scale and show proposed and future curb lines, drainage ditches, right of way, lane striping details, lighting and cross sections. The sketch alignment plan shall also include sufficient information to show that adequate sight distance has been provided. The sketch plan shall include an alignment for Cypress Road between State Route 4 and Bethel Island Road which shall be approved by the Zoning Administrator prior to filing the first final map. BF. Furnish proof to the Public Works Department, Engineering Services Division, of the acquisition of all necessary rights of way, rights of entry, permits and/or easements for the construction of off-site, temporary or permanent, road and drainage improvements. - BG. If, after good faith negotiations, the applicant is unable to acquire necessary rights of way and/or easements, he shall enter into an agreement with the County to complete the necessary improvements at such time as the County acquires the necessary interests in accordance with Section 66462 and 66462.5 of the Subdivision Map Act. 27 13H. PFevide deed Fietmfdeatoen feF all ewneFS ef paFeels eFeated by this ffbjeet that BI. Certain road improvements required may be eligible for credit or reimbursement against the Area of Benefit fee. The developer shall contact the Public Works Department,Transportation Engineering Division,to determine the extent of any credit or reimbursement for which the applicant might be eligible. Prior to constructing any public improvements, or filing of any final map, the applicant shall execute a credit/reimbursement agreement with the County. No credit or reimbursement will be made for any improvements installed prior to execution of the credit/reimbursement agreement. Credit will only be given for monies that are programmed within the next three fiscal years after final map approval, reimbursement agreements shall be executed for monies that are programmed beyond three fiscal years. Any credit or reimbursement shall be based on the cost estimates included in the Area of Benefit Development Program Report and only in proportion to each specific Area of Benefit improvement which the applicant is installing. The applicant shall be allowed full credit for the portion of the Cypress Road extension between Bethel Island Road and Sandmound Boulevard which the applicant constructs which is included in the Bethel Island subarea of the Countywide Area of Benefit. Full credit will be allowed up to the amount specified in the Area of Benefit project list for the Cypress Road extension. TRANSIT B.I. Comply with the County TDM Ordinance, and the Growth Management Program, and the Bay Area Air Quality Management District regulations regarding transportation. TDM measures that could be used by the project applicant include the provision of maps showing available transit routes, and providing information on ridesharing and vanpool services to prospective homebuyers. BK. Provide for future transit by providing bus turnouts on Cypress Road at the intersection of Cypress Lakes Drive and at appropriate locations along Cypress Lakes Drive, Sandmound Boulevard, Bethel Island Road, Cypress Road, and Country Club Drive. The location of the turnouts shall be subject to the review and approval of Tri-Delta Transit. Deposit sufficient monies, as determined by Tri-Delta Transit, for bus stop shelters, bicycle racks, and bicycle lockers to be installed by Tri-Delta Transit once regular transit service to the area begins. The deposit of monies for the bus stop facilities shall be made with the filing of Bach final map that constructs a bus turnout. BL. All homes shall be wired for telecommuting purposes. 28 BM. Provide a park-and-ride lot within the parking area for the ball fields subject to the review of the Public Works Department, and the review and approval of the Zoning Administrator. The park and ride lot shall have a capacity of 65 spaces. Provide adequate parking for the combined use of the park-and-ride lot and the ball field complex. Provide bicycle racks and lockers. The design of the park and ride portion of the parking lot, including bicycle racks and lockers shall be subject to the review and approval of the Zoning Administrator. BN. The design of community facilities, such as a clubhouse or a community park, shall provide for and encourage the use of bicycles. At a minimum this shall include bicycle racks and bicycle lockers. As an example, providing lockers at the clubhouse to store golf clubs would allow residents to bicycle to the golf course, rather than drive to the golf course with their clubs. ADVISORY NOTES A. The project lies within the 100-year flood boundary as designated on the Federal Emergency Flood Rate Maps. The applicant should be aware of the requirements of the Federal Flood Insurance Program and, the County Flood Plain Management Ordinance (Ordinance No. 90-118) as they pertain to future construction of any structures on this property. B. This project may be subject to the requirements of the Department of Fish & Game. It is the applicant's responsibility to notify the Department of Fish & Game, 1701 Nimbus Road, Rancho Cordova, California 95769, of any proposed construction within this development that may affect any fish and wildlife resources, per the Fish & Game Code. . C. This project may also be subject to the requirements of the Army Corps of Engineers. The applicant should notify the appropriate district of the Corps of Engineers to determine if a permit is required and if it can be obtained. D. The applicant shall be required to comply with all rules, regulations, and procedures of the National Pollutant Discharge Elimination System (NPDES) for municipal, construc- tion and industrial activities as promulgated by the California State Water Resources Control Board, or any of its Regional Water Quality Control Boards (San Francisco Bay- Region II or Central Valley - Region V) E. The applicant will be required to comply with the requirements of the Bridge/Thoroughfare Fee Ordinance for the Countywide Area of Benefit, Bethel Island subarea as adopted by the Board of Supervisors. F. Comply with the requirements of Reclamation District #799 including but not limited to development of CC & Rs, issuance, paying permit fees and water quality programs. G. Comply with the requirements of the Ironhouse Sanitary District. ` 29 H. Comply with the requirements of the Oakley and/or Bethel Island Fire Protection Districts ortheir successor. |' Comply with the requirements of the Health Services Department, Environmental Health Division. J. Comply with thg'r8qUirennentS of the Building Inspection Department. Building permits are required prior tnthe construction of most structures. K. Comply with the requirements of the Oakley Water District. L. The applicant will be required to pay an environmental review fee of $875 for the Department ofFish and Game at the end of the appeal period. Failure to do so will result in fines. In addition, the approval is not final or vested until the fee is paid. A check for this fee shall be aubnniDLad to Contra Costa County for submittal with the final environmental documents. M. The applicant is advised that the tax for the police sonviCem district is currently oat by the Board Of Supervisors at $200 per pnrog| annually (with appropriate future Consumer Price Index [CPI] adjustments). The annual f88 is subject tomodification by the Board of Supervisors in the future. The current fee for holding the election is $QOO and is also subject to modification in the future. The applicable tax and fee amounts will be those established by the Board at the time of voting' N. This project is subject to the development f88S in 8ffRC1under County Ordinance as of November 2' 1980' the date the vesting tentative map application was accepted as complete by the Community Development Department. These fees are in addition to any other development fees which may be specified in the conditions of approval. The fees include but are not limited to the following: Park Dedication: $1 ,350 per unit except an reduced by the provision of public parks. AB/aa SUBXU/7562C.AB 4/1/83 4/5/93'EC (a) FINDINGS For ""TING TENTATIVE MAP 7562 AND EXCEPT. - TO CUL-DE-SAC STANDARDS FOR THE CYPRESS LAKES & COUNTRY CLUB PROJECT The East County Regional Planning Commission of Contra costa specifically finds as follows: A. Approval of Vesting Tentative Map #7562 1. The Cypress Lakes & Country Club project is consistent with the County General Plan. The General Plan includes an "Off-Island Bonus Area" designation for the property which permits single family residential development at 1-2 .9 dwelling units/acre with recreational amenities. The project is consistent with such designation. The project is within the County Urban Limit Line. The staff reports for the East County Regional Planning Commission meetings on February 1 and March 1, 1993 , include a discussion relating to the project's consistency with the General Plan which is incorporated herein. In addition, the Environmental Impact Report (EIR) prepared for the project also contains discussions on the project's consistency with the General Plan which is incorporated herein. 2 . The design of the subdivision will provide for future passive or natural heating or cooling opportunities. The project proposes to design all homes to meet energy efficiency standards of 10% more than the requirements of Title 24 of the California Code of Regulations currently in effect. The design of the subdivision with its varied exposures will allow for future passive or natural heating or cooling opportunities in the design of the homes. Such opportunities will be taken into account in the project design consistent with the conditions of approval and mitigation measures. 3 . The discharge of waste from the project in the existing sewer system will not result in violation of existing requirements. The EIR prepared for the project addressed sewage disposal at Section 3 . 10, pp. 3-200 through 3-206. The project applicant is in the process of requesting annexation to the Ironhouse Sanitary District, and will pay all applicable facility capacity fees. In addition, the project will comply with all the Ironhouse requirements. The EIR confirmed that the project will mitigate all potential impacts by providing the necessary sewer improvements and paying applicable fees consistent with Ironhouse requirements. (EIR at p. 3-206. ) -1- EX fn "UT 4. Pursuant to Government Code Section 66474 , the Planning Commission must deny a tentative map if it makes any one of seven listed findings. (Section 66474 (a) -(g) . ) The Planning Commission confirms that it does not make any of such findings, and rather finds the following in the affirmative: a. The map is consistent with the County General Plan for the reasons set forth above. b. The design and improvements of the subdivision are consistent with the County General Plan for the reasons set forth above. The lot configuration and general design of the subdivision using the plan unit development approach are consistent with General Plan and its goals, policies and implementation measures. Rezoning to planned unit development allows clustering of home sites and preservation of large parts of the property acreage as permanent open space (i.e. , the golf course) . C. The site is physically suitable for the residential/ recreational development. The County General Plan and its Environmental Impact Report specifically designates the site for residential/recreational development and found the site physically suitable for such development. The project EIR further thoroughly evaluated the impacts of the development and found residential/recreational development suitable. For reasons set forth in the Findings on the EIR for the project, the Planning Commission confirmed that the project is suitable for the development. d. The site is physically suitable for the density of development. The County General Plan designates the area for 1-2 . 9 units per net acre for projects that include recreational amenities. The project includes a density of 2 . 21 units per acre. The project includes recreational amenities such as, a lake community, beach and tennis club, water channel, an 18-hole golf course, wetland area mitigation and public and private parks. The project EIR reviewed and analyzed the sites' physical suitability for the density and recreational amenities, specifically in its sections regarding Land Use; Geology, Seismicity and Soils; Vegetation and Wildlife; Public Services; and Utilities. The EIR and the Findings thereon, confirm the site's physical suitability for the density of the project. -2- e. The design of the :7,ubdivision will cause environmental damage (-,-- _;_njure fish, wildlife or their habitat. A Special-Status Species Survey of the project site was conducted to determine whether any sensitive, threatened, or endangered (Special- Status) plants or animals inhabit the project site. The survey methods included a literature review of prior field surveys included in the Contra Costa General Plan, the Bethel Island Areas Specific Plan, the Department of Fish and Games Natural Diversity Database, the California Native Plant Societies Inventory (1988) and the U.S. Fish and Wildlife Services list of candidate and federally listed plants and species. In addition, field surveys of the project site were conducted on May 20, 24 and September 4, 1991 to search for Special-Status plants, map vegetation and characterize wildlife habitats for the potential support of Special-Status animals. The EIR contains a specific analysis of the project's impacts on fish, wildlife, and their habitat. (Section 3 .4) The project includes Wetland Habitat Mitigation Monitoring Plan and a Channel Enhancement Plan for the protection of wetlands, wildlife and associated habitat. The Planning Commission's Findings on the EIR confirm that the project with incorporating mitigation measures will have an insignificant impact on fish and wildlife. f. The design of the subdivision will not cause serious health problems. The EIR analyzed health issues in the section on Human Health. (Section 3 . 11. ) In addition, additional healthand safety issues were analyzed as part of the EIR's discussion on Geology, Seismicity and Soils and Hydrology and Drainage. (Sections 3 . 7 and 3 .8 . ) Several geotechnical/ hydrology reports were prepared and analyzed in the EIR. Based on such reports, and other information set forth in the EIR, the project design will be one of stability and safety. 9- The design of the subdivision will not conflict with easements, acquired by the public at large, for access through or use of, property within the proposed subdivision because there are no such easements. -3- B. Approval of Exceptions to-. Cul-de-Sac Standards Pursuant to Section 92-6. 002 of the County Subdivision Ordinance, an exception is granted to the street system so as to allow cul-de-sacs that serve more than 16 dwelling units with a length of greater than 700 feet (ref. Section 92-4 . 018 of the Subdivision Ordinance) , based on the following findings: 1. There are unusual circumstances or conditions affecting the property. The circulation system complements the natural features of the area and the new recreational amenities provided by the project. Moreover, the circulation configuration allows the project to provide additional open space and recreational amen-ities. 2 . An exception is necessary for the preservation and enjoyment of a substantial property right of the applicant. The exception will permit the new residences to access and enjoy the recreational amenities that the project has to offer as contemplated by the County General Plan. 3. The granting of the exception will not be materially detrimental to the public welfare or injurious to other property in the territory in which the property is situated. The traffic analyses in the EIR does not indicate that the proposed cul-de-sacs will cause detriment to the public welfare or injury to other property in the territory. 4. The project approval complies with all other road design standards of the County Subdivision Code. -4- RECOMMENDED FINDINGS FOR REZONING TO PLANNED UNIT DISTRICT (P-1) (FILE #2918-RZ) and PRELIMINARY AND FINAL DEVELOPMENT PLAN (3032-90) FOR THE CYPRESS LAKES & COUNTRY CLUB PROJECT A. The East County Regional Planning Commission recommends that the Board of Supervisors of Contra Costa adopt the following findings in approving the rezoning to Planned Unit Development (File #2918-RZ) and Preliminary and Final Development Plan (3032-90) : 1. The applicant has indicated that they intend to commence construction within two and one-half years of the effective date of final project approval. The applicant's intent is demonstrated in its letter to Art Beresford dated March 30, 1993 . 2 . The Cypress Lakes & Country Club project is consistent with the County General Plan. The General Plan includes an "Off-Island Bonus Area" designation for the property which permits single family residential development at 1-2 .9 dwelling units/acre with recreational amenities. The project is consistent with such designation. The project is within the County Urban Limit Line. The staff reports for the East County Regional Planning Commission meetings on February 1 and March 1, 1993 , include a discussion relating to the project's consistency with the General Plan which is incorporated herein. In addition, the Environmental Impact Report (EIR) prepared for the project also contains discussions on the project's consistency with the General Plan which is incorporated herein. 3 . The findings made as part of the certification of the EIR are incorporated into these findings by reference. Those EIR findings confirm that the project, with mitigation measures, will constitute a stable, harmonious project, in harmony with the surrounding neighborhood. The project enhances the recreational character of the area by providing a golf course, a man-made lake and water channels, a beach and tennis club, public and private parks and pedestrian/bicycle trails. 4 . A planned unit development is desired when application of conventional zoning regulations to a large-scale development may create a monotonous and inappropriate neighborhood. Further, the planned unit development is intended to allow diversification in the relationship of 1 E" Iff - various lot sizes and open spaces, while ensuring subst.antial.complIance with County General Plan. (County Ordinance 84-664 -1%'�' -�.�) The plan unit development on this project allows for diversification of lot sizes, avoiding a "cookie-cutter, " monotonous development, and allowing for clustering of the home sites while preserving open space land areas (i.e. , golf course, lake and water channel) . Rezoning to planned unit development further allows better conformity with their recreational amenities offered by the project as contemplated by the County General Plan. Rezoning to planned unit development further allows the County the opportunity to place strict conditions of approval on the project design and grading to help protect the environment and promote sensitive design. 2 EXHIBIT. "Fit RESOLUTION NO. 12 -, 1993 RESOLUTION OF THE EAST COUNTY REGIONAL PLANNING COMMISSION OF THE COUNTY OF CONTRA COSTA, STATE OF CALIFORNIA, REGARDING CERTIFICATION OF THE ENVIRONMENTAL IMPACT REPORT; REQUEST TO REZONE TO PLANNED UNIT DISTRICT (FILE #2918-RZ) ; AND FOR APPROVAL OF PRELIMINARY AND FINAL DEVELOPMENT PLANS (FILE #3032-90) AND VESTING TENTATIVE SUBDIVISION MAP NO. 7562, IN THE BETHEL ISLAND AREA FOR THE CYPRESS LAKES & COUNTRY CLUB PROJECT. WHEREAS, Three Sisters Trust owns property consisting of approximately 685.9 acres in Eastern Contra Costa County, such property being located on Hotchkiss Tract in the Bethel Island Area, approximately 2.7 miles east of Oakley. The project site fronts on the east side of Bethel Island Road between Cypress Road and Sandmound Boulevard, fronts on the south side of Sandmound Boulevard East of Bethel Island Road and fronts on the west side of Sandmound Boulevard north of the Cypress Road extension; and WHEREAS, on November 2 , 1990, applications were filed and subsequently revised for' the rezoning of the project property to Planned Unit District (P-1) (File #2918-RZ) ; Preliminary and Final Development Plan approvals (File #3032-90) , and for Vesting Tentative Map approval (Subdivision #7562) to develop 685.9+ acres into 1, 330 single-family homes with recreational amenities; the project is named Cypress Lakes & Country Club; and WHEREAS, on February 6, 1992 , staff prepared an Initial Study and issued a Notice of Preparation indicating an intent to prepare an Environmental Impact Report (EIR) on the project; and WHEREAS, on August 13, . 1992 , staff prepared and issued a Notice of Completion of the first Draft EIR for the project; confirmed that copies of the Draft EIR were available for review; requested written comments from the public by September 28, 1992; and gave notice of -public hearings on the Draft EIR on August 31 and September 21, 1992; and. WHEREAS, on August 31 and September 21, 1992 , the East County Regional Planning Commission duly noticed and held public hearings on the first Draft EIR; on September 19, 1992, the East County Regional Planning Commission held a field trip to the project site; and on October 12, 1992, the East County Regional Planning Commission duly noticed and held a public hearing on the rezoning, preliminary and final development plans, and subdivision; and WHEREAS, numerous written and oral comments were received on the first Draft EIR from local residents, agencies, and other interested parties and a revised Draft EIR was prepared to respond to the issues raised; and Page 2 RESOLUTION NO. 12 1993 WHEREAS, on December 31, 1992, staff, after providing .proper notice, made available copies of the revised Draft EIR for public review, and requested written comments from the public by February 16, 1993; and WHEREAS, on March 19, 1993, staff, after providing proper notice, made available copies of the Final EIR for public review; and on March 26, 1993, staff made available copies of the Addendum for review; and WHEREAS, on February 1 and February 8, 1993, the East County Regional Planning commission duly noticed and held public hearings on the revised Draft EIR; and on March 1 and March 29, 1993, the Planning Commission duly noticed and held public hearings on the rezoning, preliminary and final development plans and subdivision; and WHEREAS, on March 29, 1993, the East County Regional Planning Commission certified the EIR and Addendum subject to the Findings being brought back to the commission; WHEREAS, the East County Regional Planning Commission having fully reviewed, considered and evaluated all the testimony and evidence submitted on this matter finds the following: NOW, THEREFORE, BE IT RESOLVED that the East County Regional Planning commission: • affirms their certification of the EIR and Addendum as being adequate under the California Environmental Quality Act; • adopts the Statement of Findings and Overriding Considerations; 0 adopts the Mitigation Monitoring Program; 0 approves Vesting Tentative Map for subdivision #7562 dated July 2, 1992 providing for 1, 330 single-family dwelling un'its in a lake community, with an 18-hole golf course, beach and tennis club, channel, public and private parks, school site, fire station and a surrounding levee, subject to the Conditions of Approval; • adopts the Findings for the Vesting Tentative Map for Subdivision #7562 and the . Exceptions to the Cul-de-sac Standards; and r Page 3 RESOLUTION NO. 12 - 1993 All of these documents are on file with the Community Development Department. BE IT FURTHER RESOLVED that the Planning Commission's approval of the Vesting Tentative Map and adoption of the Findings for the Vesting . Tentative Map are contingent on the Board of Supervisors approving the rezoning and preliminary and final development plans and accompanying documents. BE IT FURTHER RESOLVED that the East County Regional Planning Commission finds that the project is consistent with the County General Plan and incorporates by reference the discussion on the project's consistency with the General Plan contained in the February 1 and March 1, 1993, staff reports and EIR; and BE IT FURTHER RESOLVED that the East County Planning Commission finds that the project contains sufficient recreational amenities to justify the proposed project density of 2 . 21 units/acre. BE IT FURTHER RESOLVED that the East County Regional Planning Commission recommends that the Board of Supervisors certify the EIR and Addendum and APPROVE the following: • Requested rezoning of the site from A-2/A-3 to P-1 (File #2918-RZ) ; • Preliminary and Final Development Plans dated July 2 , 1992 (File #3032-90) ; • Findings for Rezoning to Planned Unit District. All of these documents are on file with the Community Development Department. BE IT FURTHER RESOLVED that the East County Regional Planning Commission recommends that the Board of Supervisors adopt findings and related documents as may be required for planned unit development projects. The decision of the East County Regional Planning Commission was given by motion of the East County Regional Planning Commission on April 5, 1993, by the following vote: AYES: Commissioners - Maybee, Sobalvarro, Andrieu, Hanson, Planchon, Wetzel , Hern NOES: Commissioners - None ABSENT: Commissioners - None ABSTAIN: Commissioners - None Page 4 RESOLUTION NO. 12 1993 BE IT FURTHER RESOLVED that the Chair and the -Secretary of the East County Regional 'Planning Commission shall respectively sign and attest the certified copy of this Resolution and deliver the same to the Board of Supervisors all in accordance with the Planning Law of the State of California. I, Herbert Hern, Chair of the East County Regional Planning Commission of the County of Contra Costa, State of California, hereby certify that the foregoing was duly called and held in accordance with the law on April 5, 1993, and this Resolution was duly and regularly passed and adopted by the above vote. -'�HCRMR�N Chair of the East County Regional Planning Commission, County of Contra Costa, State of California ATTEST: XecTiltarythe East County t -R-e-glonal P11nning Commission, County of Contra Costa, State of California r Findings Map _ two . A2 'A-2 . 3 JN :•: •. :•: :::: :':' • W m A3 LJ Rezone From A-2 To(P-t '9=,"eu- tSZAwo Area I, N Tc�Bt_2T ��► —Chairman of the East County Regional Planning Commission,Contra Costa County,State of California, do hereby certify that this is a true and correct copy of 'PA��z c G 2q G 74S -0 14-2-7 14-TCL oB -MVP CAINUIZU S Iq?Zs ZnNtNe M�►o indicating thereon the decision of the East County Regional Planning Commission in the matter of SAzeAAatj ?AI q -�LZ Chairman o e East County Regional Planning Commission,State of California ATTEST S of tAest County Regional Planning Commission,State of California M Findings Ma A-2 i T 9y y O _ G O A2 HOLLAND �A TRACT _F,1 - - 9fl . A 3 ... Rezone From�Z TVP-4 lscrA%� Area Ir gt4 .Chairman of the East County Regional Planning Commission,Contra Costa County,State of California, do hereby certify that this is a true and correct copy of G 2� G H Z N-2 i ar- -rwa Cnum-cis__._ �A74s 2n��w6 MAP indicating thereon the decision of the East County Regional Planning Commission in the matter of A 'S�-'t-°"'►°'' M Chairman of tKe gast County Regional Planning Commission,State of California ATTE ry 0 dast County Regional Planning Commission,State of California r Findings Ma l- A:3 . -It+ =` 1 :. . o 1 Z 5 1 * A-3 1 x m r f CYPRESS RD ) :;:: ;.•:•:.::, Rezone FromZ Tom-i +�� Area I•- -� � �-�� —.Chairman of the East County Regional Planning Commission,Contra Costa County,State of California, do hereby certify that this is a true and correct copy of _ AC.,. 6:1:2-, [ 745 . k- _IA I A? Zn UU'& MAP indicating thereon the decision of the East County Regional.Planning Commission in the matter of IAlq -22- Chairman of ast County Regional Planning Commission,State of California ATTE ec etary East County Regional Planning Com ssion,State of California Findings Map---- --- - --. - ....... a-p_--- --- - --. - -R;5_ T - HOLLAND r:. TRACT „-- . 0=1 v o=� c O Q C +� 2 1 A-3 X. T :Y: R f 1 � X. Rezone FromA-7- To(P-i ISLA"o ,area tffc-22.aax .Chairman of the East County Regional Planning Commission,Contra Costa County,State of California, do hereby certify that this is a true and correct copy of ?At„c 147 _Zn,�iu b MAP r indicating thereon the decision of the East County Regional Planning Commission in the matter of S At-AAA,& Chairrriieoftfietast County Regional Planning Commission,State of California ATTE ry of East County Regional Piasng Com ion,State of California Findings Map -kill IJ'\ N I I �\ 1 \\j rt •r W ... �•3 � 1�. : ' .. n + t t r � , i� Rezone From A-2. To(P-1 S=1411 ISLAbba Area 1, 4A"E,-gsQ*A t —Chairman of the East County Regional Planning Commission,Contra Costa County,State of California, do hereby certify that this is a true and correct copy of Z"� =7'45 � 4{�Z�, N-2�b t�'� •rt+� C•n �.c tom_ r _i a'N ZQIJ W a indipting thereon the decision of the East County Regional Planning Commission in the matter of A �• �e,�o� Chairman of th East County Regional Planning Commission,State of California ATTES ry of East County Regional Planning Commission,State of California 4 Findings Ma .3 0 6 + + O HOLLAND N F TRACT A•2 \; Z � O C 2 _� F• + T 1 A•3 + Rezone From A-2 Tog)=t 1Sr►+r-L- LQLA"a Area I _ LS ill Q� Chairman of the East County Regional Planning Commission,Contra Cosa County,State of California, do hereby certify that this is a true and correct copy of G Z:Z, j9ZcA• � A74s ZcsN lyd a MAP indicating thereon the decision of the East County Regional Planning Commission in the matter of $-'s. 5aZ.AM6Id ?AIDC —�LZ Chairm` n of East County Regional Planning Commission,State of California ATTE S4&Wry o# §ie'East County Regional Planning Comfnission,State of California , ' Agenda Items #2, #3' & #4 �. Community Development Contra Costa County . ` EAST COUNTY REGIONAL PLANNING COMMISSION MONDAY, APRIL 5, 1993 '— |. ` CHARTERED LAND & CATTLE CO. (Applicant) THREE SISTERS TRUST (Owner), ' ~°"''`, File # 2° '"``Z' The -`pr^"''` 'eq"="^" "pp~~= to '"z"`'= 685'9�-a^=" of land from General Agricultural District (Ar2) and Heavy Agricultural District (A-3) to Planned Unit District (P-1) for 1'330 single-family dwelling units/lots, golf course, school site,fire station, public park' private park areas, lake,channel and a surrounding levee. CHARTERED � � S TRUST (Owner), County File # 3032-90: The Applicant requests approval of preliminary development plan for o clubhouse, beach dub, public park, and maintenance facility and approval ofafinal dava|Vpnnant plan for the residential uses, QO|fcmuruS/driving range, wetland mitigation, |4k8' channel, and surrounding levee. CHARTERED LAND & CATTLE CO. (Applicant) - THREE SISTERS TRUST ' County File Subdivision # 7562: The Applicant requests approval to subdivide 685.9+ acres of land into 1 '330 sing|a-farni|y |nta along with recreational amenities. The subject property for the Cvo/eaa Lakes & Country Club project is located on Hotchkiss Tract in the Bethel Island planning area, approximately 2.7 rni|ao east of Oakley. The project site is bordered tothe west by Bethel Island Road, to the north and east by SondnnOund Blvd., and to the south by agricultural uses. (Parcel No. 032- 210-029/032-220-005, 7, 8, 12, 28) (CT 3010.00) (ZA: G'27' 28/H-27, 28). There are pending development projects to the west and south of the site. U. RECOMMENDATION ` Mild �ifibb it. tifl NP-001 I.S110. V ix AD f ` 2 UiCHRONOLOGY The 1978East County Area General Plan provided for the preparation ofaspecific o|an-' for the Bethel Island Area. After completion of two draft environmental impact reports, certification ofa final environmental impact report and several specific plan drafts, the Bethel |a|end Area Specific Plan was adopted bythe'Boand on July 10' 1990' Since that time, the following additional events have occurred: ' ' Date Event 8/28/90 Applications filed for the proposed project, #2918-RZ' 3032-90. SUB 7582. 10/8/90 Development Agreement approved on project site based on the General Plan and Specific Plan 11/2/90 Initial project appUcadonadearnodoVnnp|ete 1/29/91 County General Plan adopted by the Board of Supervisors 4/16/91 Specific Plan amended to reflect new General Plan 10/91 Superior Court upholds Bethel Island Area Specific Plan 12/9/81 Development Agreement amended toreflect new General Plan. Later rescinded 12/12/81 Project application revised to reflect new (39nene| Plan 2/6/92 Initial Study and Notice of Preparation (NOP) completed on the project 7/1/92 Project application revised tnreflect concerns expressed on the NDP 8/12/92 Draft BR released for the project 8/31/82 Public hearing onDraft BR 8/21/92 Public hearing unDraft BR ' 10V12/92 ^ Hearing on project _ 10/26/92 Hearing on project continued indefinitely pending redrafting of BR ` 11/4/92 State Appeals Court orders the Bethel Island Area Specific Plan and BR tobeset aside ' ' _-'- -- ' - - , ,. 3 12/92 Settlement agreement reached/rescind BR, B|ASP and Development Agreement. � 12/31/92 Revised DraftBR released onthe project. Comments to 2/16/93. 2/1/93 Hearin g on Draft BR and project - BR hearing odntnugd to 2/0/93. ` Project scheduled to 3/1/83. 2/8/93 Closed hearing on E|R. Written comments accepted until February 18, ' 19S3' 3/1/93 Fearing on project - testim[ny taken ' public hearing continued to April 5, 1993. 3/28/83 Public hearing ' aU interested pardeonenodcad for special hearing. (\/. OTHER DISCRETIONARY APPROVALS Several other discretionary approvals will be required to fully implement the Cypress Lakes & Country Club project. Certain aspects of the project may require LAF[<J approval or reorganization and annexation. LAFCO approval may be needed for the reorganization of the Sphere of Influence and annexation of the project site into the Oakley Water District and Contra Costa Water District for provision of water; the Ironhouse Sanitary District for the provision of sewer; and possible consolidation of the Dok|oy and Bethel Island Fina Districts in the Bethel }a|end planning area. Other annexation and/or possible consolidation may be necessary for other services. The establishment of o park maintenance district, other special districts, and other necessary financing mechanisms for infrastructure may also be necessary. Approvals and/or permits may also be necasmary . from State and federal agencies (e.g., Department ofFish Q' Game, U.S. Army Corps of Engineers, FEMA, o1c')' The project may also be requesting a development agreement. A final development plan will be subsequently submitted on the clubhouse, beach club, public perk and maintenance facility. V. GENERAL INFORMATION A. General Plan. The site is designated in the General Plan as Agricultural Land (AL) and Open Space ([>S). The AL designation permits a density of one dwelling unit per five acres. There is also an overlay land use designation on the site of "Off-island Bonus Area" which allows increased residential densities ` undor certain circumstances. Projects that exhibit a recreational character through the inclusion of substantial recreational amenities can increase the - density to 1-2'8 units per-net acre. This development has an overall density of 1'9' du/n8tao. ` B. ' Zoning. The present site zoning is A'2 and A-3. The request is to rezone the ' site to P-1 for 1,330 units. ' ' ' 4 C. . /\ draft env\ronnn environmental impact report (E|R) was prepared 'onthis project. The Final BR has been prepared and the response to oornnmantm document sent tothe State. ` D. Processing Approach. The projectiebeing processed undor1hepresent County General Plan. E. Existing Use. The existing use of the site imegricu|tura|'(cattegrazing) and consists of several fenced pasture areas, with irrigation and drainage canals crossing the property in various locations. A few hornoe and agricultural structures are located on the projects site. These structures are primarily located along the unimproved portion of Cypress Road and east of Bethel Island Road. There are two PG&E power lines (both 500 KV) and one USA pVvxgdine (230 KV) located on the south-west corner of the site. The USA povverUna is slated to be removed when the VVAPA pbvver line (500 KV) is erected t0the north-east of the current lines on the project site. The new 500 hv power Una has been constructed and is being energized. F. Surrounding Uses. The Hotchkiss Tract, in which the project area is |wcatod' is bordered onthe west byJersey Island Road, mnthe north by Dutch Slough and Bethel |a)and, on the south by Rock Slough and on the east by Sandnnound Slough. The majority ofHotchkiss Tract ioin agricultural use. About 131 acres have been developed for nayidanbo| uses and about 2 acres have been developed for connn*oro\ol use. The }ands in agricultural use have marginal productivity. Hotchkiss Tract is part of the mainland and in those areas adjacent tothe waterway, \tisprotected byalevee. The residents inth8area ~ are primarily single-family hurnon and most are located along Sandnnound Boulevard and have docking facilities on Sandrnound Slough. There is one multiple-family housing development located on Sandmound Boulevard. A small commercial area is located on Sandmound Boulevard and on Bethel Island Road near the bridge. There are three residential structures qn srnoU lots that are surrounded by the project. G. Other Development Proposals in the Hotchkiss Tract Area. There are presently three development applications on file in the Hotchkiss Tract area.The Lesha/Landing application ([].P. 3031'90, 2817'RZ, sub 7588) iaon361 acres located east ofJersey Island Road between Dutch Slough and Cypress Road' The site also fronts for a distance on Bethel |a|mnd Road. This _ epp!iumdmn proposes 571 residential hOrnea and other uses. At the present time, this application isbeing held inabeyance at applicant's request. Thp, Snuth River application (D.P. 3014-81 ' 2955'RZ' sub 7488)isf0r the 355 acre parcel located to the south of the Leaher Landing and Cypress Lakes and Country Club projects. The application is proposing 575 residential units with a levee breach. Planning staff has requested revised pians for the project. This project is also being ha|6 in abeyance at applicant's request. ` ` ` . 5 Subdivision #7801 is filed on the 78 acre site north ofSendmound Boulevard just north of the Cypress Lakes development. |thoa proposal for 14 lots with aremainder for the commercially designated land along Bethel fa|endRoad� At this time, the application is incomplete. H. GOU The soil in the project area issomewhat different thhnthe soil found in other portions of the Delta. Soil in the project area consists of silty sand and sand, silty clay, nominal amounts of organic clay or silt and nominal amounts of peat' These soils are generally permeable and have m |0vv expansion potential. Soils on the site are Class ||| and bm|Vvv in agricultural usefulness. V|. PROPOSED PROJECT A. Proposed Physical Improvements. The Cypress Lakes and Country Club project would be constructed on approximately 685'9 acres consisting of seven parcels. The project would consist of 1 ,330 single-family residential units. /n addition, the project would include an 18-hole QO|f course with amenities, an internal levee system, a man-made lake and channel, a wetland mitigation area, a daycare facility, parks, afira station, beach club and a potential school site. ` The project would be constructed in phases. The phases would be timed to coincide with necessary infrastructure improvements (i.e.' snvvaga' storm drainage, water facilities, roadway improvements, etc.). The first phase would include basic grading of the site and excavation for the man-made lake and channel. Material excavated for the lake and channel would bgused toconstruct alevee system around the project site for flood protection. The levee system will require FEMA approval before any home constructed on the site could be occupied. Preliminary grading for the golf course would coincide with levee construction. - The proposed residential development vvnu|d be on lots ranging in size from approximately 5'000 square feat to 10'000 square feet. Residential lot densities vvmu|d average approximately 5.4 units per acre. The overall density of the project is 2.21 unite per acre. The project design would avoid most of the ewadnQ Smasmno| wetlands (6.52 acres) and waters of the United States (2'86 acres) present on the project site. However, approximately 0.75 acres ofwetlands would be impacted by the proposed project. The project design would include replacing the impacted wetlands through restoration and enhancement of existing wetland habitat on the project site. ' major land use as proposed by the project, including approximate acres of coverage, are summarized as follows: ` — ---- - ' ' 6 ^Land Acres Single-family Residential (1'330 units) - ' ` - �242'g ' Fire Station 2.0 School Site 7.4 Beach Club/Daycare Center ' 2.4 Roadway Right-of-Way 74'6 Lake/Channel � � ' 61 .0 Parks 33.7 Golf Course 170'3 Existing Wetlands 6.5 Levees & Road 54.6 Drill Sites 10'5 OpanSpeoe/VVetland Mitigation 11.0 TOTAL 685'9 _ B. Pr000sed Internal Circulation Imorovements. The primary entrance tothe site would be via Cypress Road at its intersection with Bethel Island Road' /\ secondary access vvOu|d be provided via SanUrnound Blvd. at the north end of the project site. Cypress Road vvOu|d be extended through the project site as the primary collector roadway. Residential neighborhoods vvOu)d be accessed bynninternal road system consisting of primary roads, secondary loops and Cu\-dS'saCStoprovide access tOthe individual neighbors. ' C. Proposed Internal Levee. The General Plan precludes substantial development onthe project aitnun\aamthearea \onsrnovodfrornthef}oodhazanjznne. Tha project site is proposed to be removed from the flood zone through the construction of an internal levee. Material for the levee will be obtained from the excavation ofthe lake and channel. The levee will beconstructed tVFEMA standards for an Urban Standard Levee' If the project is approved, an application for rannnvol from the flood hazard zona will be sent to FEMA and reviewed byits local engineer. The engineer will use the standards ofthe U-S' Army Corps of Engineers in its review. In defining the applicable standards, the . levee type, location and any other unique characteristics itmay entail are taken into consideration. D. The proposed project would also include various storm dnainage, vvotnr system, sewage disposal, and public utility improvements. On-site storm drainage improvements would include curbs, gutters, and drain inlets to on underground conduit system which would be designed in accordance. with q[}-799 and County standards, The proposed system would pump excess runoff into Sand Mound Slough. The project xvou|d include on-site detention of storm water in the proposed lake and channel detention facilities. ` ^ 7 The project would obtain sewer services from the IronhOuse Sanitary [>n-mite sewage facilities would include a gravity mgvver system, with stations and pumps. Sewage from the-site would enter the existing force main\nBethel Island Road. The applicant has received o "will serve" letter from the |ronhouse Sanitary District. ' Water would beprovided bythe Oakley Water District. To providewater tothe site, off-site improvements including transmission Un�� �ron) Highway 4@t Cypress Road would be provided. (]n'ai1a vva1ar facilities would include 6-inch, 8-inch and 10-inuh underground distribution pipes. The applicant has received a "will marVa" letter from the Oakley Water District. Other utilities, such as electricity and solid vvauta disposal, would be provided by existing service providers. E. Pr000s ed Mitigation. The proposed project hesbeendesigngdtonaduoaoertain impacts through the incorporation of the following measures: _ 1 Levee System: The project design includes construction of a levee system around the project site to remove the proposed development area from the flood hazard zone' The levee system would be certified by FEMA prior tothe construction of houses 0nthe site. 2' The project includes a system of channels and lake to provide otormnvvaterdetantion on-site to reduce ' drainage impacts nn RD'789faci|itiga. 3. The project includes innovative water quality management strategies to maintain .acceptable water quality in the project channels and lake. Management strategies include the use of specific plant species to remove pollutants from the water and mechanical circulation of water tnimprove flushing action. . 4' The* project would impact 0.75 acre oGthe 9'18 acres of wetlands on the site. The project would include the replacement of impacted wetland through the enlargement and enhancement of existing wetlands on-site. The 0'75 acres impacted would be replaced with approximately 2'75 acres ofwetland. 5' The project indudeanneosuremto monitor ground subsidence that may result from da-vv@horinA activities , associated with construction of the project levees, channels and lake. Monitoring vvaUo and settlement plates would be used to monitor ` construction. If groundwater levels Or a0i| subsidence exceeds acceptable levels, construction activities would be stopped and remedial actions,taken. ' ` ' _ 8 6. The Drn]aut includes detailed landscape plans for the project levee and common area. The landscape plans include lists of desirable plant mpeoi8a,�irdQatiOntechniques andOther landscape criteria. Additional landscaping vvoudbe provided around the project perimeter outside the levee a|ong�Sandrnound Boulevard and Bethel Island Road toreduce visual impacts onadjacent r4sidento. ' 7. ' The project includes 61anStOenhance the primary drainage ditch ("main drain") into a channel of approximately 8'Oacres insize. /\ new channel isalso proposed in the north/south direction and would connect t0the proposed lake. The second channel would be approximately 110 acres in size. The channels are proposed to provide additional riparian habitat and visual interest tOthe project. The banks of the channels would be sprigged with vviUovv and cotton- wood cuttings toprovide riparian cover. 8. maintain " o°"' "' °~~^^=': ""^ ^'~u, efficiency= ^`"=a'rds.of Title= 24 ", '° ~' This would be achieved through the incorporation ofdesign features into each home toreduce energy consumption. 8. Provision of School Site: To help mitigate the project's potential impact on local sohoo| facilities, the project plans include the dedications of o 7.4 acre school site on the project site. The school site would be .dedicated t0the Oakley BennentarySchool District for the construction Ufanew elementary school inthe Bethel Island area. 10. The project p|enoinc\* dga2 acre Site for a new fire station on the project site. The fire station is located near the project entrance at Cypress Road and Bethel Island Road. The project would also include construction ofonew fire station facility onthe site. Provision of fire station on the project site would improve fire protection services for Hotchkiss Tract and the Bethellsland area. 11 . The project o|mmo have been developed toavoid culturally sensitive areas present 0nthe project ai1e. Portions of the project site known to Contain cultural resources have either been avoided or are proposed for less disruptive uses such as parks and playgrounds. ^ 12. The proposed project . ino|udemapproximately 33 acres ofpublic and private parks-primarily ` located south ofthe proposed extension ofCypress Road. In addition other recreational amenities are being proposed including: o |ake' gn|f course, beach club, traits, and open space corridors. 9 13. Affordable Housing Fee: The project applicant has agreed to pay a in- lieu affordable housing fee equal to $3,333 per residential unit. For the proposed project this fee would generate approximately$4;432,890 for the County's affordable housing programs. These fees would be paid at the time of issuance of building permits. As pan alternative, the project applicant may .construct a portion, or all, of the affordable housing units on-site. 14. Homeless Fees: The project applicant has agreed to pay an in-lieu fee to the County's Homeless Trust Fund. The amount of this fee would be determined by the County and paid upon issuance of building permits for the project. VII. AGENCY COMMENTS A. Environmental Health Division: No comments. B. Building lnspection Department: Single Family Residences shall have finished floors above the flood plain. C. Department of Water Resources: No comments. D. Contra Costa Water District: See attached letter. E. U. S. Fish & Wildlife: See attached letter. F. Oakley Fire Protection District: See attached letter. G. Oakley School District: See attached letters. H. U. S. Army Corps of Engineers: See attached letter. I. Liberty Union High School District: See attached letter. J. State Lands Commission: See attached letter. K. Knightsen.Community Council: See attached letter. L clarna ion strict #7 9. .::. Y' d letters j�t �{ <:Betf��t::IsEand 1� e.Pst�teetian.C3tstr�et. See,atta�h�d.,Iett�r N. Comments were also requested from a number of other agencies and groups. Among them were the Greenbelt Alliance, California Native Plant Society, East Bay Regional park District, the Mosquito Abatement District, Sierra Club, Department of Fish & Game, Oakley Municipal Advisory Council, Oakley Water District, Ironhouse Sanitary District, Bay Area Air Quality Management District, . ' 10 and the Pacific Gas & Electric Co. Noresponses were received from the ` mbnva agencies orgroups. f\ number did, however, comment onthe Draft Elk for the project. . Vill. DISCUSSION , - The project BR discusses the 'a relationship to and consistency with the General Plan. That discussion isincorporated herein and eurnmnahi8dbelow. In staff's determination, the project iaconsistent with the County General Plan. ` A. Consistency with General Plan. 1 Land Use. Land use policies which are most applicable to the proposed project include those associated with recreation-oriented development (Policy 3-69), growth management standards and the relationship to the Urban Limit Line (Policies 3-5 - 3-14)' The proposed project conforms to the General Plan land use designa- tions for the area, The site consists ofapproximately 885.Sacres. The net density ofthe project ia2.21 units per acre. The "Of#a|andBonus Area" permits 1-2.9 units per net acre for projects that include substantial recreational amenities. The recreational amenities that are being proposed include a lake community, beach and tennis club, channel, on18-ho\eQcUfcourse, wetland area mitigation, and public and private parks. From staff's perspective, the project includes substantial recreational amenities,permitting the proposed density of 2.21 units per acre. There may beadditional recreational amenities recommended by Staff. The project iaconaistentvxithCountypo|icynagmrdinQgrovxthnna' g8- rnentotendardsandthe provision ofessential community aan/ioem by installing the necessary infrastructure toserve the project. The project isalso consistent with the County Urban Limit Line policies because the development area (approximately 685.9 acres) imwithin the Urban Limit Line. The General Plan contains specific land uae' oo|ioiasfor the Hotchkiss Tract area. The nmo'Vr policies. include limited new development of recreation-oriented units (Policy 3-69); the provision of internal levees that must be approved by FEMA utilizing Army Corps of Engineer ~ standards (Policy 3-74); and the payment ofaProtection Fee toacquire development rights on agricultural lands, open space orwetland areas, . or to provide financing for farmers tncontinue agricultural production (Policy 3-80). The project iacnnoistantvviththeCountypo|icyrggardinQ development ofprimarily nycmoadon'nhSntedunits byproposing a project 'with recreational ornenidoS. The project proposes an internal levee consistent that will be approved by FEMA and proposes to pay a Protection Fee. ` 11 2) Growth Management Element. The County's Growth Management Element establishes policies and standards for traffic levels of service and performance standards for traffic, fire, police; parks arid recreation, sanitary facilities, water, and flood control and drainage to insure generally that public facilities consistent with adopted standards are provided to the residents of the County. (Policies 4-1 - 4-5). The project will meet the County's growth management standards and policies by 1) providing an internal circulation system with an LOS of D or lower, and constructing off-site circulation improvements, 2) dedicating land for a fire station and contributing equipment, 3) paying a fair share fee towards the rehabilitation of the Oakley Sheriff Station to achieve the County's standard of 155 square feet per 1,000 population, 4) providing 26 acres of park land, 5.6 miles of pedestrian trails and paths, 170 acre golf course and 60 acres of a lake and channel, 5) receiving a "will serve" letter from Ironhouse Sanitary Distrust, 6) receiving a "will serve" letter from the Oakley Water District, and 7) proposing an internal levee and financing all costs of necessary drainage improvements. 3) Transportation and Circulation Element. The Transportation and Circulation Element establishes transportation goals, policies and implementation measures to assure that the transportation system of the County will have adequate capacity to serve planned growth in Contra Costa County through the year 2005. The County has estab- lished performance standards for traffic. The traffic analysis conducted for the project in the EIR evaluated the project's conformance with the goals, policies and performance standards of the County and the proposed traffic improvements to insure project compliance. The project proposes an internal circulation system with an acceptable level of service (LOS D or lower) and to construct off-site circulation improve- ments. 4) Housing Element. The Housing Element presents specific policies and actions for housing provision, based on the premise and policies of the residential land use component of the General Plan's Land Use Element and provides an adopted County Housing Plan that will help the County to qualify for housing aides and grants. The project is consistent with the County's Housing Element because the proposed project is consistent with the General Plan Land Use Map which designates the site for residential-recreational development. The project will provide reasonably priced housing. In addition, the proposed project will - contribute an affordable housing fee of $3,333 per approved residential unit. Based on 1,330 units this fee would generate approximately $4,432,890 for use by the County in developing additional affordable housing. ' 12 5) The key Public Facilities/Services E|ernan1 policies relating to the project pertain to growth management standards for water, sanitary and sewer, drainage and flood contro[ ' public protection, fire protection, solid waste management, school and, child care. Some of the key policies include: ` ' � Encourage water service agencies and LAFCO to annex lands planned for urban development by the Ge' era| Plan into their service area; (Policy 7-19) 0 At the projectapprova| atug8' the applicant shall be required to demonstrate that adequate water quantity and quality can be provided; (Policy 7-21) 0 At the project approval stage, the applicant shall be required to demonstrate that wastewater treatment capacity can be _provided; (Policy 7-33) ` � New development shall be required to finance its legal share of the full costs ofdrainage improvements necessary toaccommo- date projected peak flows due to the project; (Policy 7'44) w Aesthetic, environmental and recreational benefits shall betaken into full consideration when determining the costs and benefits of alternative drainage system improvements; (Policy 7'42) . m Asheriff facilities standard of 155 square feet ofstation area per 1,000 population shall bemaintained; (Policy 7-57) � 0 Locate fire stations vvithin~one and one-half rnUeS ufdevelop- ment. (Policy 7'62) 0 New development shall pay its fair share of costs for new fire protection facilities and services; (Policy 7-84) 0 The environmental reviewprocess ahaUbeutilized tomonitor the ability nfarea schools toserve development; (Policy 7'14O) and 0 Proposed development projectsahaU be required to provide for child care facilities in accordance with the General Plan; (Policy ^ 7-153) .' The project isoonsiotent with above policies for the following reasons: ^ � The water analysis oOntainod in'tha BR identifies an adequate available source from Oakley Water District and the projectmiU request annexation into the District. ` ' - , ` .�� 13 ^m The applicant has received a "will serve" letter from the [hakkov Water District confirming that water capacity ioavailable serve the project. 0 The applicant has received "will serve" �� the |�nhmu� _ Sanitary District identifying adequate capacity to serve the development. � The project vviUonnstruotun'aitadr8inaQafoci|itiea(|ake,channa| and golf course detention basins) toprotect property and provide public safety by accommodating the 100 year storm event. 0 The applicant is proposing to pay a fair share fee towards the rehabilitation of the Oakley Sheriff Station to achieve the ' County's standard of 155 square feet per 1,000 population. 0 The applicant is dedicating land for e fire protection facility and donating equipment. 0 The project proposes a potential school site ofapproximately 8 acres. � The project proposes o day oan8 center on-site. G) Conservation Element. The policies contained in the Conservation Element primarily pertain to the preservation and conservation of the County's vegetation, wildlife and vvmtor nsmVurcaa. The project im, consistent with the policies contained in this a|arnent by widening the existing primary drainage canal for wildlife, utilizing clear span bridges for road crossings to minimize impacts to wildlife movement along the drainage canal, The project also proposes to replace wetlands on-site, in m ratio of a minimum of 3 acres for every 1 acre impacted. Avvatiand delineation on the project was conducted in accordance with the 1987 and 1988 rnonua|o and was approved by the U. S. /\rrny Corps of Engineers. 7) The policies of the Open Space Element primarily pertain to the provision of adequate park land and the preservation of significant open space area within the County. The project is consistent with the pCdioima contained in this a|mrnent by providing a cVnno/etm ^ mymtonn of public parks and open space corridors. The project proposes ' a1mtai of 26.6 acres of park land and 5.6 rni|ea of pedestriantrai|mand - . patho. Moreover, the project contains 170 acres of open space lands in its golf course, 61 acres of |ohe and channel and 14 acres of other open space and wetland mitigation areas. ^ ' 8) Safety Element. Key policies contained in the Safety Element which ^ pertain to the project primarily address the need for appropriate ---- ' ' 14 geotechnical analyses and erosion control measures. The BR contains athorough evaluation ofgeologic seismic and soils conditions and risk. Moreover,the BRproposes satisfactory rnitigatiorirneesurestmmitigate' the impacts on potential liquefaction and other soil impacts identified. The project also proposes an internal levee system to remove the area from the' flood plain. The project also prmpo 'eo erosion control nnoamunam. 9) Noise Element. The Noise Element sets forth noise standards for various land uses. The noise a1andonj for single-family residential uses iSa CNEL of 60 dBorless. The project, a|ong with its mitigation, would be consistent with the County's policies because noise levels onthe project site would be within normally acceptable |mvm|a' |}{. AREAS OF CONCERN The following describes portions of the project vvhena staff is recommending revisiona tothe plan. Staff iarecommending that the levee for the project benoovedevvayfrumn Smndrnound Boulevard aothat the levee's visual impact upon residences inthat area is reduced. Staff recommends that the levee bebrought generally south from the end of the channel at the easterly side of the site and around the wetlands area and thence across and down 10the south aaitwas originally proposed. That area to the east of the levee could then be used as part of the golf course and also provide anarea for open space and/or recreation. Staff recommends that the area to the east of the levee not be developed as a boat and RV storage area. Staff recommends that this part of the plan be deleted. it should be noted that within Bethel Island area that there are other sites designated Commercial where facilities such as boats and RVs storage could be developed, as well as areas that are zoned Agricultural where boat storage facilities with a land use permit can be approved if near enough to m publicly accessible boot |mok launching facility. The area east ufthe levee should baleft asopen space, fenced and/or become part of the golf course. Staff is also recommending that the Cypress Road extension be designed on that it avoids the triangular property owned by K4ny. Cn|arnon. The road should either run to the south of the site ortothe north' In any case, the owner of that property would ' have to be given proper access tqCypress Road. Staff is recommending that the proposed, park area ' be developed so that any parking facility be located otthe corner of Cypress Road extension and Cypress Lakes Drive _ and away from the Ogren and/or DannaUeyresidences. Further' staff recommends that ifoQrepab|etothe O! ren's and DanneUay'a' alot line adjustment b8accomplished where their property would boextended somewhat to the east oDthat they front upon proposed Cypress Lakes Drive. Further, the applicant would build each property owner m 1D-footwide paved driveway ifthe owner ioagreeable. )fnot, they could continue to use their present graveled driveway. The extended portion of the driveway which ' intersects the Cypress Lakes Drive should be paved to avoid gravel on the roadway. ^ 15 ' Staff further recommends that the existing private properties within the site be properly fenced prior to development of the site around them. Staff recommends that the proposed day care center be moved over to the neighbor- hood eighbophood of the proposed aohom| site. The size of the day care center will be determined bythe needs for day care within this development. ` Staff also recommends that the levees be constructed in some'manner other than _ using deep dynamic compaction, especially in areas near to existing residences. The noise from this type of construction has the potential for causing significant negative impacts on nearby occupants. It would be preferable to excavate and over-fill to compact the area. . Staff recommends that atthe end of various cul-de-sacs around the lake, trails be extended into the park areas between these neighborhoodS, notably aothat the small open space areas-are interconnected. The smaller landscaped areas, south VfCypress Road should bgdeveloped with atot lot play area accessible toresidences inthe area. Staff recommends that the undefined open space area behind Lots 61 to 64 and 87 to 69 be deleted and that the area be placed into the various surrounding lots. Staff also recommends that a road be extended south from Cypress Lakes Drive to connect with the development to the south give internal circulation to this site as well as to neighboring property to the south which is under application for development at this time. Staff iSalso recommending that, prior todevelopment of the lakes on this site, a lake and channel maintenance program be developed subject to the review and approval of the Zoning Administrator after review byecompetent|innno|ngiat knowledgeable in the _ maintenance oflakes such as proposed' This may require additional fees to be paid for the |imnno|oOiata review. X. FINAL APPROVALS Afinal development plan would bemequirodforthebeeuhcdub' thego!fdu6housaand the day care oantgc The perk' if public park' would not require further review and approval through e further development plan. It would, of course, have to be acceptable tnany landscape and lighting district developed for nnointemono8 of the park. Prior to any development on the site, LAFCO would have to determine which fire district this site is to be located in. The site is partly within the Bethel Island Fire Protection District and partially within the Oakley Fire Protection District. |fotthe time that the plan to record Phase 1 of this development is requested and both of these fire districts are still inexistence, then the site would have tnannex into and/or de-annex into one district. ` ' 10 Secondly, staff recommends that prior todevelopment of any portion mfthe ' ` north of Cypress Road that final development plan for the golf clubhouse site. The golf clubhouse site would be required to have adequate parki''and' of course, the golf course will have to be opened to the general public on o fee basis. The intent Ofthe general plan inthe area and off-island bonus area iothat sites can bedeveloped with e higher density if appropriate publicly eccaoaib|a recreational faoi|itieaare provided. ' I . The Q�� course vxouN need tusubn1� m �na| maintenance n|an. The golf course should b8maintained inanlargely organic manner. The golf course maintenance plan would be subject 1oreview and approval of competent landscape architect and/or golf course architect for uonnnn8nto on its feasibility. The beach club area needs to bedeveloped during the development ofPhase 2with the requirement that priortooccupancy ofresidences inPhase 2' the beach club would bainstalled and inoperation. The area where the proposed day care center had been would then baused aa�addidona| landscaped reureadona|area. The plan for the proposed park and/or parks additional be submitted prior to the development of Phase-1. ' The park area within the southwesterly portions of the aite'shaU be landscaped and improved to at least passive park use as well an a couple of baseball fields prior to occupancy of residences in Phase 2. As mentioned above, the parking area for the parks shall be located away, as much as pouaib(o, from the Ogren and OanneUey residences. The area otthe north Vreasterly portion ofthe site that isoutside of the relocated levee shall be used as open space area or golf course. The day care center shall be sized to handle the number of children within the development requiring day care as well as some overage for use for residents that live outside ofthe development. The day care center final development plan shall be.fi|ed prior torecording the final map for Phase 3. As far as the school site and the fire station, these ehoU be developed at the determination of the local school and/or fire district. |tshould be noted that the proposed drill sites adjacent tmthe project site vvill require a final development plan approval/land use permit approval when and if a request to drill a gag well on the site is filed. This area is being developed as residential area ' and any type ofgas well development in0r.nearresidential area require approval ufa land use permit. |nthe case ofonarea zoned P-l' ofinal development plan would be required for all drill-sites atonce mreach drill site separately. Staff recommends that the purchasers of property within 300 feet of high tension lines be noticed through the CC 8^ Ra of the fact that they are near a high tension line. Staff also recommends that the roads crossing the channels such as Cypress Road and Cypress Lakes Drive, as well as others, be designed such that the channel ornmainQ allows water fowl and/or other small animal to cross underneath the road and not have to come up to go over the rood to return to the channel. These pipes should be Set ' sVthat they are generally half under/half above water, perhaps with a large enough ` ^- ' . ` 17 diameter for ducks and/or geese 1opass through. The design should also allow ` mnlgU mammals to pass through with some type of pathway developed. [3eSi0na of these under-crossings ofthe road shall basubmitted tothe Zoning Administrator for review and approval after review by the State Department of Fish & Game as to their adequacy and/or need. The applicant has proposed that extanaivqtrails bedeveloped along the levees on this site as.well as a trail across the north central part of this site along one ofthe east-west channel. Staff recommends that the trails south ofCypress Road be developed with Phase 1 to Phase 3 and that the trails north of the Cypress Road as well as trail across the site be developed with Phase 4' th 00 IillUth' ' ` 18 Sa:se.t:un::::tha:>a:baw!e:<:staort::ad><:th :::G:enra::: la::: . ��-:::i<'t si': ;?iS'���=:ias:':: `� :S .:i::`%;>;`�-`:::?===>:;>>:_?>< >i{ ;��<_ ::�i..:::;::`:;:�:>:;;::::-�::::.:;:>:::>:.::;::;>;:"-:3:::;:::<:'<:>::::%::r::;:: ::::;:.::,;:.y.:;r..:::;::;.�-:: ::.;�:::>�•.:5:;:;: rnrats ... ta ratX. n :to:;tC a:::B.ctard<aC:: u a r ...p...� a AB/aa RZXCX/2918-RZ.AB 10/7/92 1/25/93 2/23/93 4/1/93 _- .`..._.i.««�.t....«.._�-.«_-...r�«..._�....«._r«-...w -r.rw �✓r.. _.ter_.-..r-r�r.+Jrr,+...w.• r,��.J««w..__..«—+w.- - w�-Jw.�r.i 4w v.--ssV 7 v r • ♦ l V l.'.... �.CYPRESS LAKES & COUNTRY CLUB PROJECT SUMMARY rev 1125193 PROJECT APPLICATION The applicant seeks to rezone from A-2 to P-1, obtain preliminary and final development plan approvaI,. "aqd approval of a vesting tentative map. The General Plan designates the pfoject area as "Agricultural Lands" (IDU/5-AC) with an overlay designation of"Off Island Bonus Area" (I -2.9DU/AC). Projects that propose substantial recreational amenities are allowed the higher density. The project proposes a net density of 2.21 DU/AC and includes substantial recreational amenities. PROPOSED LAND USES (ACRES) Residential 242.9 School Site 7.4 Roadway ROW 74.6 Fire Station 2.0 Lake/Channels 61.0 Beach Club/Daycare 2.4 Golf Course 170.3 Open Space/Wetland Mitigation 11.0 Parks 33.7 Exist. Wetlands 6.5 Levers &Rd 63.6 Drill Sites 10.5 TOTAL 685.9 Acres WETLANDS Existing-6.52 Ac Disturbed- 0.75Ac Mitigation-2.25Ac (3:1 replacement ratio) .TOTAL 8.77 Acres GENERAL Lot Size.(SF) 5000+ 6000+ 7000+ 8000+ 10000+ #of Units 597 304 91 182 156 TOTAL 1330 Units UTILITIES & PUBLIC SERVICES WATER: Oakley Water District-WiIl serve letter on file SEWER: Ironhouse Sanitary District-Will serve letter on file STORM: Contra Costa County Public Works Department. POWER: PG &E LEVEES/DRAINAGE: Reclamation District 799 FIRE: Oakley or Bethel Island Fire Protection POLICE: Contra Costa County Sheriff Department SCHOOLS: Oakley Unified and Liberty Union High School PRIVATE MAINTENANCE RESPONSIBILITY MASTER HOMEOWNERS ASSOCIATION-Club facilities, parks - NEIGHBORHOOD HOMEOWNERS ASSOCIATION -Common area landscaping TRAFFIC & CIRCULATION - - - SIGNALItED INTERSECTIONS: Bethel Island Road x Cypress Road Sellers Avenue x Cypress Road Knightsen Road x Cypress Road ROADWAY & INTERSECTION IMPROVEMENTS: Bethel Island x Cypress Road Cypress Road-Machado Rd to East of Knightsen Rd Sandmound Blvd x Bethel Island Road PEDESTRIAN CIRCULATION: 5.6 miles of off street pedestrian trails and paths VA Wide ON wr Im PF Wr P-mou 7, sat got at p IN AD AWE In gi On w I oll I lilt �=P. sm lilt OAF Ill" 0. �:tti +. •qlj.. r.•C Hilllt ';�► :i€ Ilia ►�► U fi std*,►`�:,, IL �' • t 1 V NOW ! r Stu 9 A M ,[► > r • fir♦ � Pi y� a�� �� r •., art �ti Atte fsifffif 'i � rj �`�}*r����-�5� _!1►�.���� _ _ - � �jff� � I� I� I► +,;'�;1 c'I!� tr...••.•:• rrrr,4ii. ';`:;. �� I f' ♦ f fj illi ♦r .i?(i.# >S..,s..•.• f�i:'i�»t• � � — OR! All :: :: ������1�� l �ll1i1! t'1 A ����� �♦�`,�,t��// ,i ,,��`,��If♦i fi��*fig ♦ � "'�t1!![[ It![�� � �� I�j ♦ �1�,�� �,��'i . �`�,��uifrlil ruliii,.�.►i�i����II P�p P-P fa i'loss Mr., Mi it W W& OAF 0 IFA ;k w-� I PAP man FA gm p WoNt 2 NOW, \\'�a'CON TRA COSTA WATER DISTRICT 1331 Concord Avenue "J� % .'.;i;t :. . ►ik i i` PO.Box H2O Concord,CA 94524 � Q� # PH t, (415)674-8000 FAX(415)674-8122 " (415)d39-9169Toll Free from y: : ,:.t;:i i : u:I`LL ?a;{ >; cor Eastern Contra Costa County November , 1990 v..: Mr. Arthur Beresford Directors Contra Costa County Community Bette Boatmun Development Department President 651 Pine Street Ronald E Butler 4th Floor, North Wing Vice President Martinez, CA 94553-0095 Donald P.Freitas Paul a lEHuPellegrini Subject: Agency Comment Request (10-19-90) on Cypress Lakes Paul t:Hughey 3 9 Y � EdSeegmiller Golf and Country Club Rezoning, Vesting Tentative-Map, GenerdlManager Preliminary and Final Development Plans (County Files 2918-RZ/3032-90/Tract 7562 Dear Mr. Beresford: Thank you for the opportunity to provide comment on this large project at an early stage. It is our understanding that an EIR will be prepared on this and the nearby Lesher Keys Project for which we will have an opportunity to provide further comment. Specifically, to this project, the Contra Costa Water District (CCWD) has no comment regarding its potential to impact CCWD resources such as the Contra Costa canal or its San Joaquin Delta water supplies because it is located at least 0.4 miles northeast (and down gradient) of the canal, and no levee breaching is proposed that could potentially affect Delta water quality. The future Draft EIR, however, will need to address treated water supplies to the project which would appear to be provided by the Oakley Water District (as indicated in the application as a future annexation) . The DEIR will need to cover Oakley Water District (OWD) and CCWD sphere of influence expansions (CCWD provides raw water to OWD) for future LAFCO annexation or reorganization actions. Thank you again for the opportunity to review this major project. Kindest regards, CONTRA COSTA WATER DISTRICT 1 d Seegmiller General Manager °ES/DP:ps Enclosures United States Department of the Interior- N 0 FISH AND WILDLIFE SERVICE 10 Fish and Wildlife Enhancement rn Sacramento Feld Office . c�rtt—j o 2800 Cottage Way,Room 111803 C c.-� N 3 Sacramento,Ca4fomia 95825-1846 =a:c� Novembe�AiG, 3990 M tV . In Reply Refer To: ..{ PPN #864 Mr. Art Beresford Community Development`Department 651 Pine Street 4th Floor, Ninth Wing Martinez, California 94553-0095 Subject: Application for Rezoning, Cypress Lakes Golf Course and Lake Community, Bethel Island, Contra Costa County, California Dear Mr. Beresford; The Fish and Wildlife Service (Service) has reviewed the Application for.Rezoning for the Cypress Lakes Golf Course. and Lake Community development on Bethel Island. In a letter dated November 1, 1989, the Service provided comments on the Draft Environmental Impact Report for Bethel Island Area Specific Plan. A. copy of that letter is attached and is incorporated by reference. Please refer to it to gain a full understanding of our concerns. The proposed project would adversely impact :wetlands and other fish and wildlife habitat, and would be contrary to our recommendations regarding the Bethel Island Specific Plan. In particular,- it appears that there has been no attempt to avoid and minimize impacts to wetlands. Although a wetland determination has- been done, we found it to be incomplete. It also has not been verified by the Corps of Engineers. Because of- this, we are unable to fully evaluate potential wetland impacts. In addition, the proposed project would be contrary to Executive Order No. 11988 of May 24, 1977 on floodplain management. Any Federal action, including the issuance of a Corps 404 permit that would promote expanding existing levees or constructing additional levees would be contrary to Section 2 of the Order. For these reasons and because the project is not water dependent nor has any mitigation been proposed for unavoidable habitat losses, the Service would object to issuance of any Corp's permit for the project. Attachment A lists those federally listed threatened and endangered species potentially found in the proposed project area. It also. includes candidates for federal listing. The federally listed, San Joaquin kit fox may occur in the project area. This species is fully protected under the mandates of the Endangered Species Act of 1973, as amended. Section 9 of the Endangered Species Act (Act) and its implementing regulations prohibit, the "take" of a federally listed wildlife ATTACHMENT A LISTED AND PROPOSED ENDANGERED AND THREATENED SPECIES AND CANDIDATE SPECIES THAT MAY OCCUR IN- THE'AREA*-OF THE `PROPOSED REZONING OF CYPRESS LAKES GOLF COUPE AND LAKE COMMUNITY, BETHEt ISLAND, CONTRA COSTA COUNTY, CALIFORNIA (1-1-91-I-49, NOVEMBER 14, 1990) ' Listed Species Mammals San Joaquin kit fox, Vulpes macrotis mutica (E) Candidate Species Amphibians California tiger salamander, Ambystoma .tigrinum. californiense. (2)- Birds tricolored blackbird, Agelaius tricolor (2) Mammals Pacific western big-eared bat, Plecotus townsendi! townsendii (2) San Joaquin pocket mouse, Perognathus inornatus _inornatus (2) Plants Suisun aster, Aster chilensis var. lentus (2) California hibiscus, Hibiscus californicus (2) delta tule-pea, Lathyrus .jepsonil subsp. jepsoni! (2) Mason's lilaeopsis, Lilaeopsis mason!! (2) (E)--Endangered (T)--Threatened (CH)--Critical Habitat (l)--Category 1: Taxa for which the Fish and Wildlife Service has sufficient biological information to support a proposal to list as endangered or threatened. (2)--Category 2: Taxa for which- existing information indicated may warrant listing, but for which substantial biological "information to support a proposed rule is lacking. (2R)=Recommended for Category 2 status. (*)--Possibly extinct. species. Take is defined by the Act "to harass, harm, pursue, hunt,, shoot, wound, kill, trap, capture, or collect" any such wildlife species. 'Take may include significant habitat modification or degradation where it actually kills or injures wildlife by significantly impairing essential behavioral, patterns, including breeding, feeding, or shelter (50 CFR § 17.3) , Take incidental to an otherwise lawful activity may be authorized by one of two procedures. If a Federal agency is involved with the permitting, -funding, or _ carrying'out of this project, then initiation of formal consultation between that agency and the Service -pursuant to Section 7 of the Act is required if it is determined that .the proposed project may affect a federally listed species. Such consultation would result in a biological opinion that addresses anticipated effects of the project to listed and proposed species, and may authorize a limited level of incidental take. If a-Federal agency is not involved with the project, and federally listed species may be taken as part of the project, then an "incidental take" permit pursuant to Section 10(a) of the Act should be obtained. The Service may issue such, a. permit upon completion by the permit applicant of a satisfactory conservation plan for the listed species that would be affected by the project. The Service recommends that the proposed project area be surveyed for the San Joaquin kit fox. We also recommend that appropriately timed surveys be con- ducted for the candidates included in Attachment A. Should these surveys determine that federally listed species occur on the project site and are likely to be adversely affected by the proposed project, the Service recommends that the project proponent, in consultation with this office and the California t Department of Fish and Game, develop measures that mitigate for the project's direct and indirect impacts to listed species, and compensates for project- related loss of habitat: We also recommend addressing adverse impacts to candidate species and developing additional measures to offset these impacts. We appreciate the opportunity to comment on this project. If you have any questions concerning these comments, please contact Marilynn Friley at (916) 978-4613 regarding wetlands and other habitat issues; and Peggie Kohl at (916) 978-4866 regarding listed and candidate species. Sincerely, Wayne S. White Field Supervisor Enclosure cc: Reg. Dir. , (AFWE), FWS, Portland, OR Dir. , CDFG, Sacramento, CA Reg. Mgr;', CDFG, Region III, Yountville Dist. Eng. , Corps of Engineers, Sacramento EPA, San Francisco NMFS, Santa Rosa COE, Sacramento SFO-HG, Sect 7, Sacramento OAKLEY FIRE PROTECTION DISTRICT P.O.Box 207 CONTRA COSTA • oolday,Caffiomfa 94561 EUsfness Phone(415)625-2119 90 OEC -3 P141. 2: 20 DEVEL 'r E`» c,� ,November 2.7, 1990 _PT Contra Costa County - + Community Development De rtment 651 Pine Street, 4th7 , North Wing Martinez, CA 94553 ATTN: Art Beresford SUBJECT: Major Subdivision [TR 7562, 3032-90, 2918-RZ] Bethel. Island Road, N/o Cypress Road & south side of Sandmound Blvd. (WS-90-7562-PD) Oakley, CA Dear Mr. Beresford: We have reviewed the Application for a Major Subdivision, received October 26, 1990, for the subject project. The development. is to 'consist of 546 single-family lots and commercial. development. This project is regulated in part by codes and ordinances administered by this Fire District relative to Contra Costa County Ordinance 89-71. If.'approved by your office, we request that the following be included as Conditions of Approval: SPECIFIC -CONDITIONS: I. The developer shall provide an adequate and reliable water supply for fire protection with a -minimum fire flow based on the building sizeand�type of construction. The required fire flow will be•determined at the time two (2) .complete sets of plans and specifications .are submitted - to the Fire District. [10.301(c) UFC] If existing water supply does not meet required fire flow for this development, structures shall be protected by approved automatic fire protection sprinkler systems, STANDARD CONDITIONS: 2. The developer shall be required to contribute Fire Facility Fees to -mitigate operational costs associated with increased service.demands throughout the Fire District. Fire Facility Fees are currently set at the rate of $480.00 per individual residential dwelling unit and $0.10 per square foot of commercial development. C.C.Co. Com. Dev, Dept. ABII-27a November 27, 1990 - Page The developer shall pay all required Fire Facility Fees prior to the issuance of any building permit. 3. The developer shall submit two (2) complete sets of plans and specifications of the subject project, including any required built-in fire protection systems, to the Fire District for review and approval prior to obtaining building permits for construction to insure compliance with minimum requirements related to fire and life safety. [2.20.6 UFC] 4. The developer shall provide an adequate and reliable water supply for fire protection as set forth in the Uniform. Fire Code. [10.301(c) UFC] S. .The developer shall provide fire hydrants of the East Bay "type, as specified by the Fire District (and City Engineering Department) . Location of hydrants will be determined'by the Fire District upon submittal of two (2) copies of a tentative map or site plan. [10.301(c), UFC] 6. The developer shall provide access roadways with all-weather driving surfaces of not less than 20 feet of unobstructed width, and not less than 131-. 6" of vertical clearance, to within 150 feet of all portions of the ' exterior walls of every building. Access-roads shalL not- exceed '20% grade,, shall have a minimum outside. turning radius of 42 feet, and must be capable of supporting the imposed loads of fire apparatus - (20 tons) . [10.207(a) UFC] 7. Dead-end fire department access roads. in excess of 150 feet long shall be provided with approved provisions for the turning around of fire department apparatus. [10.207(a) UFC] 8. Access roads and hydrants shall be installed and ,in ice prior to combustible construction, n., [10.301(e), UFC] 9. The developer shall provide illuminated addressing located on all buildings in such a manner as to be plainly visible and legible from the street or road fronting the property. [10.208 UFC] Art Beresford, Project Planner Community Development Deptirtment 7 February 1991 Page 2 Therefore, the Oakley Union Elementary School District requests approval of Subdivision 7562, Cypress Lakes Country Club,-'be conditioned.upon the inclusion for provision of school sites within the formal application and that Cypress Lakes, participates in a financing plan to construct the needed facilities. . This request is allowed for in Contra Costa County's new. General Plan, Section 7.0 - Public Facilities/Service Element which -states, ".Where negative fiscal.impacts are.. indicated, include specific mitigation measures as conditions of project approval or carefully consider the 'appropriateness of approval. A project .shall not.be .approved, unless such mitigation . measures are guaranteed and fully implemented by the project proponent." If you should have any-questions or'need additional information,-.,please feel.free'.to contact me.. _ - ':i 1, .. v�• Frank J .fiengel Superintendent :..;.cc:. .,L..Newhart, .and Planning:Consultants T.ToA,ksor, Supervisor,-5th Disti icf;::Contra Costa County: t, , V Contra Costa.County;Community.Development Department 1 + Y rJ CONTRA COSTA Administration Offices: (415)625-0700 THE BEST AND CETT/NG BEITER91 FEB -8 P11 1:.34, Gehringer School: (415)625-2293 POSTOFFICEBOX7 Oakley School: (415)625-2281 OAKLEY.CALIFORNIA 94561 C%1;1.1�1 may O'Hara'Nrk School: 625-5- 060 DEVELOP1,11ENT DEPT J, 7 February 1901 Art Beresford, Project Planner Contra Costa County Community Development Department 651 Pine Street Martinez, California 94553 Re: Subdivision #7562, Cypress Lakes Country Club Dear Mr. Beresford, I had the opportunity recently to meet with Ms. Lynn Salomon Jochim of Chartered Land & Cattle Company to discuss the above referenced project. The purpose of the meeting was to begin a spirit of communication between her company and the Oakley Union Elementary School District to hopefully resolve the District's concerns regarding their proposed residential development. 11s. Jochim expressed a willingness to I work toward this end. The District has two main concerns as addressed to you in my letter dated November 14, 1990. Theseconcerns are as follows: I. The subdivision site plan does not Illustrate an elementary school site. A residential project of 1,351 units clearly generates the need for such a facility and should be located within the plan boundary. If a mitigation is required on the site for flood concerns, (i.e., Vintage Parkway School Site) that mitigation should also be the responsibility of the developer. Based on the District's Student Generation Factor, it is not anticipated that this school would have available capacity to serve any additional developments In the area. 2. Our second concern pertains to the construction funding for the new school. Developer Fees collected by the District are Insufficient for this purpose. Although the District has been successful In the past In obtaining State funding for site acquisition and school construction, and will continue to seek State funding in the future, it is anticipated that soon State funding will- no longer be-available. Therefore, In order for the District to build facilities to house students generated by the Cypress Lakes development, assistance on the local level will be necessary. These .are serious concerns to the District as we provide a quality education for all of our students. Without these issues appropriately mitigated, the alternative will be severe overcrowding in all District facilities. C.C.Co. Com, Dev. Dept. AB11-27a November 27, 1990 Page 3 -" 10'0 ' The developer shall locate trash enclosures such that commercial dumpsters are 'not stored or placed within five (5) feet of combustible walls, openings or combustible roof eave lines. (11.201(d) UFC] 11. The owner/developer shall apply to the Fire District for any permits which may be necessary to comply with Fire Code requirements. (4.101 UFC] 12. Where open space is to be maintained for public or private use, the. developer shall provide access into these areas from public ways. These access ways shall be a minimum 16-foot width to accommodate fire department equipment. All open spaces, when left in their natural state, shall meet the Fire District's weed abatement standards. (10.207(m) & 88.104 UFC] It is requested -that a copy of the completed Conditions of Approval for the subject project be forwarded to this office when compiled and adopted by the planning agency. If you have any questions regarding this review, please contact the undersigned at (415) 757-1303. - _ sincerely, JOE TOVAR Fire Chief- By:_ t.�j BILL BANOVITZ JT:BB:ap Fire. Inspecto cc: Robert Dal Porto Leo Mantelli A.J. SA1omon C.C.Co. Building Dept./Soen Thung " File . (WS-90-7562-PD) Y Administration Offices: (415)625-0700 THE BEST AND GETTING BETTER l FEB Gehringer School: (415)625-2293 Oakley School: (415)625-2281 v° POST OFFICEBOX 7 OAKLEY.GAZfFORNtA44561 .�� O'Mara Park"Schooi: (415)'625-5060 y- {!�' � �E.��� O DYS �f 7 February 1991 Lynn Salomon Jochim, Vice-President Chartered Land & Cattle Company 101 Ygnacio Valley Road, Suite 400 Walnut Creek, California 94596 Re: .Cypress Lakes Country Club, Subdivision #7562 Dear Ms. Jochim, Thank you.for, our .recent meeting regarding the Cypress Lakes proposed' development. As .we .discussed. elementary students generated by this development alone Will create a need for a 500-600_ student elementary school. This school.site should be-located within the site plan:of the development and based.on the current subdivision plan, no school site Is described.. Based on the Oakley Union Elementary School District's Generation,Factor, -it is not anticipated.that thl.a.school_would have:available capacity to serve-any additional developments in the area.. An additional concern pertains to-.the:,construction funding of the new school..The Developer Fees that the-District collects are. not sufficient for this purpose and assistance from ...the State will soon.no'longer-;be an alternative. Therefore, to build a school*to house the elementary-students.generated`_bp the:Cypress.•Lakes development,,,assistance-on the local. . level.will be'needed. As you continue-with, the development-process of your,project, we look forward to working with. you to:-mitigate.:our_ concerns.-:-:.Please keen:us informed as new-:information becomes available. Sincerely; . Frank J. engel Superintendent cc: L. Neuhart, Land Planning Consultants . : K:.Wand ryr:Contra Costa County Community Development Department DEPARTMENT OF THE ARMY U.S.ARMY ENGINEER DISTRICT,SACRAMENTO CORPS OF ENGINEERS } � 1325 J STREET REPLY TO SACRAMENTO,CALIFORNIA 95814-2922 ATTENTION OF September 27, 1991 Regulatory Section.- (9100843) _ . Ms. Lynn Jochim ; Chartered Land and- Cattle Company P.O. Box 430 Walnut Creek, California 94597 Dear Ms. Jochim: CO Sl --- This letter concerns . the project known as the Chartered '` Land and Cattle Company property, located in Sections 22 and 23, Township 2N and Range 3E, Contra Costa County, California. We have reviewed and verified the wetland delineation map of the Chartered Land and Cattle Company property submitted to us by letter dated August 8, 1991. Our jurisdiction in this area is under Section 404 of the Clean Water Act. A Department of the Army permit is required prior to the placement of dredged or fill material into waters of the United States. Accordingly, a permit will be required prior to filling any of the 9.18 acres of waters present on the Chartered Land and Cattle Company site as identified on the verified wetland map. The type of permit processing required will depend on the type and amount of waters which would be lost or substantially adversely modified by fill activities. This verification is valid for three years from the date of this letter. Please refer to identification number 199100843 in any future correspondence concerning this project. If.you have _ any questions, please write Karen Shaffer at the letterhead address, Room 1444, or telephone (916)557-5269. Sincerely, Tom Coe Chief, Regulatory Unit 1 Copy Furnished: _ Huffman & Associates., Inc. , Mr. James Gibson, 4204 Power Inn Road, Sacramento, California 95826 Land Planning Consultants iNc. 239 MAIN STREET,SUITE E ■;-PLEASANTON, CA 94566, ■ (415)846-7007 ■ FAX:(415)846-5314 December 2, 1991 FAX 646-4098 .1` r Mr. Phil Batchelor, Clerk of the Board of Supervisors and , .r • County Administrator Community Development Department Contra Costa County 651 Pine Street - Martinez, CA 94553 ' "c RE: Bethel Island Development , Subdivision 7580, Lesher Keys s Subdivision 7562, Cypress Lakes Dear Mr. Batchelor: On behalf of the Liberty Union High School District, I wish to respond to your request for comments on the above referenced projects. Current conditions: The High School District's facility in Brentwood anticipates an enrollment of 2,60.0 students by 1995/96 with a Facility Master Plan capacity of 2,200 'students. The district will be required to house several hundred students in temporary housing facilities that will severely , impact the existing campus. The district successfully passed a bond measure in 1988 to purchase a school site in Oakley to build their second high school. Students generated- by development in the Bethel Island/Hotchkiss Tract will attend this facility when it is built. Based on State approvals and construction schedules, - it is anticipated that -the earliest date the Oakley High School can be •built would be for the 1996/97 school year. As previously stated, the existing campus will be severely • overcrowded. well beyond the district's Master Plan and 'the State's standard for school site/student- capacity requirements. Future Facility Needst Clearly, the district needs to build their second high school facility in Oakley as soon as possible due to existing development within the County. For the past two years, the district has been negotiating with developers in the City of Brentwood on an agreement to fund the construction of this school. A determining "- factor in these negotiations has been the participation of developments in the County in a fair share dollar amount towards the second high school. Brentwood developers are not willing to Serving Public Agencies Mr. Phil Batchelor December 2, 1991 Page 2 finalize an agreement for a sclibol that students generated from their-developments are not likely to attend. Although the district has purbhased the property that the school will be located on, they do not have a funding source for construction of this facility. Funding Alternativest. State funding is not a viable alternative for the district although the district currently has an application for funding in process. Local bond measures may not be an alternative based on the recent state historical elebtions for school facility needs. Therefore, local development assessment' funding may be the only solution. Without fair share participation by both. the county and city, the second high school facility can not be built. Conclusion/Request: Based on the aforementioned information, the district requests that development in the Bethel -Island planning area, as well as all other County .developments, be conditioned to participate in a funding plan to build the Oakley.High School beyond developer fees. This provision is in accordance to Government Code case law provisions. New residential growth/development creates the need for additional school facilities. The high school district requests that all new development in the County, as well as in the City of Brentwood, be conditioned to participate in funding the district's new facility in' Oakley beyond developer fees.. Without such an inclusion, . the new facility may not be constructed- although the need will be a cumulative reality. if you should have questions -regarding any of this information, please contact me. sincerely,- _t"aAk Laird Neuhart District ,consultant cc: Philip White, Superintendent, LVHSD T. Torlakson, 5th District, Contra Costa County Dennis:Barry-1 Community Development Dept. , Contra Costa County STATOF G"JFORNIA } PETE WILSON.Govnor STATE LANDS COMMISSION -i' EXECUTIVE OFFICE 1807-13th Street LEO T.McCARTHY,Lieutenant Governor Sacrarriento,CA 95814 GRAY DAVIS,Controller CHARLES WARREN THOMAS W.HAYES,Director of Finance Executive Officer E June 19, 1992 - , File Ref.: W 24845 Mr. Byron Turner Chief of Land Development Community Development Department County of Contra Costa County Administration Building 651 Pine St,, 4th Floor.,N. Wing Martinez,California 94553-0095 Dear Mr.Turner, I apologize for the delay in responding to your letter of May 4, 1992. As you may be aware,the current fiscal condition of the State has dramatically reduced staffing levels,including that of the Commission. You have requested that the State Lands Commission map lands subject to sovereign ownership interests within the Specific Plan area The contemporary identification of lands that passed to the State as an incident of sovereignty on September 10, 1850 is often a difficult task. We have indicated to you that we believe sovereign claims exist in the vicinity of the various development proposals now before you. These interests range from.fee ownership to the public trust and navigational easements. Under the Public Resources Code,the Commission is authorized to negotiate and settle boundaries with any person or local agency claiming an-interest in lands affected by boundaries described by the"Preliminary Description of Ungranted Tidelands Boundaries." The Commission may negotiate a boundary settlement only with the holders of record title. As we have indicated previously,we believe the County should inform developers of the need to resolve boundary uncertainties directly with the State Lands Commission. As a starting point,however,areas that are currently submerged or,subject to tidal action raise a presumption of at least some level of sovereign interest. In addition,numerous maps depict sloughs or large areas of lands below sea level in the planning area Any proposal for a levee breach(Lecher;Bones,Delta Coves)may involve public lands or have impacts on public lands. Furthermore,you should be advised that the waterward boundaries of'several of the development sites have not been established pursuant to law(Public Resources Code§6357)despite indications on some of the Tentative Maps of such a boundary between private and-public lands. One option that could enable the County to address the impact that the various development- proposals may have on public interests is to require,as a condition of approval of vesting maps, Mr. Byron Turner 2 June 19, 1992 that the proponent obtain a letter from the SLC. Such a letter would indicate one o the following: (1) no State lands are involved in the developnidnt;ar(2j State lands are involved and all permits required by the State Lands Commission have bQen obtained;or(3)State lands may be involved in the development,but pending a final determination of State land involvement,an agreement has been reached with the State Lands Commission for the project to proceed without prejudice to such determination: This method of resolving uncertainties has proved successful for both BCDC and the Coastal Commission. I hope that this will assist you to advise developers of the need to discuss,with the Commission,the potential for sovereign claims within or affecting the proposed subdivisions. Thank you for your patience. Sincerely, Dwigh E. Sanders,Chief Div ' n of Environmental Planning and Management oc: Jane Sekelsky,Chief,Division of Land Management Duncan.Simmons,Staff Counsel Matt Rodriquez,Office of the Attorney General Knightsen Community Courra-3=1" 29 H1 1, 37 P.O. Box 170 Knightsen, California' g 54r;=y'4-',._�:l:;. -: 1&41 DEPT September 28, 1992 Contra Costa - County Community Development Attention: Arthur Beresford 651 Pine Street, North Wing, 4th Floor Martinez, California 94553-0095 Re: County File No. 2918-RZ Final Development Plan 3032-90, Subdivision 7562 Dear Mr . Beresford: Since the newly elected Community Council has not had the opportunity to review the EIR for the Cypress Lakes and Country Club Project it is hard for us to make comment item by item, however, it is the consensus of the Council that the roadways in the Knightsen Community have not been addressed in sufficient detail as the current occupancy in the Hodgekiss Tract and Bethel Island areas is primarily agricultural, recreational, and retirement with a. minor emphasis on residential as pertains to commuters. in outside- employment. However, this project and the projects planned in the future will change the emphasis to residential with commuting being a more predominent element. We feel additional traffic studies need to - be done in the area of the Knightsen Post Office on Knightsen Avenue, the area in front of the Knightsen School on Delta Road, the intersection of Sunset and Byron Highway and Sellers Road as it runs adjacent to Knightsen. The Byron Highway extension to Bethel Island Road has been talked about but not addressed. It is included in the General Plan but not in the BIASP, nor has it been addressed in this EIR. This could eliminate the . traffic congestion areas listed above. We feel this is of importance to the Knightsen area as it appears to us the only improvements or mitigations are for the traffic beaded in the Oakley direction and do � not address Knightsen's concerns. ~ Sincerely yours, SETH H. COCKRELL Chairman SHC/rc cc: Tom Torlakson ,.., RECLAMATION DISTRICT 799 Board of Robert D. Gromm, Edmund B. Langes, David Dal Porto, Trustees: F. Reginald Dunning, Joseph S. Spotts. Office: 2070 Dutch Slough Road, Bethel Island, CA 94511 Address: P.O. Box 447, Bethel Island, CA 94511 Telephone: (415) 684-2117 November 20, Art Beresford, Project Planner Community Development Department County Administration Building, 4th Floor North Win 651 Pine Street Martinez, Ca 94553-0095 Subject: Comments on 2918-RZ/3032-90/TR-7562 Reclamation District 799 (RD-799) Board of Trustees makes the following comments on the proposed Cypress Lakes and Country Club project. 1- The project .owner shall fund an independent geotechnical and drainage engineering review of the project design and construction on behalf of RD-799. This review shall show the impact and a plan to alleviate the impact of the project on existing drainage pumps and systems 2- The County shall require as a condition of issuance of its grading permit the prior issuance of a RD-799 permit. 3- The County shall require final approval .by RD-799 of completion of its permit conditions before issuing final approval of any County building or grading permit. 4- All levees and drainage systems developed by the project shall be dedicated to RD-799 for access, operations and maintenance. 5- The- insurance policy carried by the project during construction shall show RD-799 as a co-insured. 6- A completion bond shall be required that will provide RD- 799 with protection for its existing levee and drainage systems. 7- The project developers will involve RD-799 in the development of the Covenants, Conditions and Restrictions (CC&R) for the parcels developed by the project, which will address RD- 799 rules and regulations and a funding program for maintenance and operations of levee and drainage facilities. 8- The project shall provide RD-799 with facilities for a corporation yard, access to the lakes, and boat berthing. 9- A water quality program shall be implemented for the inland lakes. 10- The, developer is aware the RD-799 permit fee is three. (3) percent of the project cost that requires RD-799 permitting. RD-799 ` is responsible for the maintenance of 6.7 miles of levee and the operation of the drainage system for 3100 acres. The current budget totals $.120,000, which includes a budget for engineering at $24,000. RD-799 does not have the financial resources. or expertise to competently review this project's design (Page One of Two) Page Two RD-799 comments on Cypress Lakes & Country Club or inspect its construction. Nor is it fair to the existing property- owners to sacrifice maintenance money for engineering review of a proposed development. In the past, county permits issued without RD-799's knowledge have caused two bitter experiences that were critical to levee safety and drainage. on subdivision 6610, a levee seepage ditch was filled causing ponding at the levee toe, thus reducing soil strength and weakening the levee. At the condominium project on Sandmound Blvd. , a deep building foundation excavation near a levee toe caused excessive seepage, sloughing and bubbling in the sandy soil forcing RD-799 to require emergency backfilling until safe construction techniques were developed by a geotechnical engineer.. For the RD-799 Board of Trustees, Robert D. Gromm, chairman/secretary FROM:KONICA FAX T0: 5106462254 MAR 29, 1993 3:53PM P.01 E6ER & NAKAGAWA- = :__. ..:.- MARTIN H.EDER• AN ASSOCIATION or ATTORNEYS AREA CODE 413 CRESSEY H. NAKAOAWA 680 C.ALIPORHIA STREET 'rCLCPHONE 3tse-2867 WILLIAM-J,LIES TWCNTY-BEOOND TLOOR IACSIMII.C(415) 3O0-I0gi JENNIFER K.BERG SAN rRANCISCOI CALIFORNIA 94108 4.PROFESSIONAL CORPORATION ( Vfib 4 FAX TRANSMITTAL Please route to: FAX Number 0 C-16 - From CA-emsel Date Operator The total number of pages being transmitted herewith is including this page. Specific Instructions If you do not receive all pages, or any portions of the transmittal are illegible, please call (415) 362-2657 immediately. TO: 5106462254 MAR 29: 1993 3:54PM P.02 t E S E R &, N A KAGAWA MARTIN 14.EPFR• AN ASSOCIATION OF ATTORN[YG AREA CODE 4t$ CIMESSEY.N. NAKAGAWA *150 CALIFORNIA STREET TELEPNONC 3ae-P057 WILLIAM J.4193 TWLNTY-XECONp FLOOR FAC91MtLEt1418y *OZ-1081 SAN WNCISC4,CALIFORNIA 94108 *A PROFl6SIONAL CORPORATION March 29, 1993 Harvey E. Bragdon, Director Contra Costa County Community Development Department 651 Pine Street Martinez, CA 94553-0095 Attn: Art Beresford Re: Cypress Lakes Project Dear Mr. Bragdon; I am writing as legal counsel on behalf of the Trustees of Reclamation District No. 799 which covers the Hotchkiss Tract. In response to a letter from your office dated March 19, 1993 advising the District that a hearing before the East County Regional Planning Commission .has been scheduled on March 29th for comments on the "Response to Comments document" related to the Cypress Lakes & Country Club project, the Board of Trustees of the District have directed me to write this letter expressing our concerns. As you are aware, the proposed development lies within the boundaries of Reclamation District No. 799; a special district created under California law to reclaim and drain the lands within the District and provide flood control through the con struction and maintenance of its external levee system. The subject development proposes the additional construction of internal levees-which surround reclaimed lands within the District. In the course of such construction of 'internal levees , the existing . drainage system of the District will be significantly impacted. 'Several of the technical concerns of the District upon the drainage issue and the internal levee system have been referred to in earlier comments submitted during the SIR process. Without conceding that. the "Response to Comments document"- adequately ,addresses the District's concerns on drainage and the impact of internal levees, the principal purpose of this letter is to advise the Planning Commission that there are jurisdictional issues involving the powers and responsibi'1- ities of the District vis-a-vis the powers and responsibilities of the Planning Commission that need to be recognized and appropriately addressed in the processing of an approval for this project. These issues are: :t Harvey E. Bragdon, Director Contra Costa County Community - Developmant_.Dep r-tment March 29, 1993 - Page 2 1. Internal Levee System. The proposed construction of the . internal 16Vee system requires prior or concurrent approval by the Reclamation District. Because such levees are proposed- to be constructed for flood prevention and the preservation of reclaimed lands; the District must decide whether it is willing to accept the future responsibility for the maintenance of such levees and all of the financial obligations in connection therewith. As of this date, the Board of Trustees of the District have not been in a position to determine whether the reclamation responsibilities of the District would be best served by the construction of such internal levees. This has been due to the need for a report on the condition of the existing external levees and the improvement work needed to achieve the protective levee standards presumably needed for the proposed development. The report has just been finalized for review by the Board of Trustees. The Trustees have not been able therefore to address the specific request by the project developer (contained in a letter to the District) to consider the assumption of full responsibility of and obligations for the future preservation and maintenance of the proposed internal levee system. The Board of Trustees of the District shall review and consider a finalized proposed plan for the construction of such internal levees. The Board shall also address questions and concerns about any responsibilities that the District may face with respect to the maintenance of any public roads that could be planned for construction on the crown of such levees. At this juncture, we simply want to make the Commission aware of our powers and responsibilities that must be coordinated in connection with the approval of this development. 2. Drainage System. As mentioned hereinabove, the proposed construction plan would disrupt the existing drainage system maintained and operated by the District. The Board of Trustees has not'been presented with a master drainage proposal that addresses the question of how the existing drainage system must be coordinated and operated as well, as the costs of any modifications necessary if the internal levee system is constructed- ------------------------ Harvey E. Bragdon, Director Contra Costa County Community Development Department March 29, 1993 Page 3 We assume that any District responsibility for drainage facilities that are proposed to be constructed izi connection with this development can be - discussed with the developer, ' Please contact Mr. Bob Gromm at (516) 6$9--2117 for District - involvement in and coordination of the approval .process. v ry truly yours, t ressey akagawa ! BETHEL ISLAND FIRE PROTECTION DISTRICT CO 1 TRA COSTA 3045 Ranch Lane/P.O.Box 623 Bethel Island,CA 94511 Business Phone(415)684-2211 DEC — r vJi ;�•a;ii.;` •` V F Z jj •rj.�J-« November 27,_ 1990 Contra Costa County Community Development Department •651 Pine Street, 4th Floor, North Wing Martinez, CA 94553 ATTN: Art Beresford SUBJECT: Major Subdivision [TR 7562, 3032-90, 2918-RZ] Bethel Island Road, Nfo Cypress Road & south side of Sandmound Blvd. (WS-90-7562-PD) Bethel Island, CA Dear Mr. Beresford: We have reviewed the Application for a Major Subdivision, received October 26, 1990, for the subject project. The development is to consist of 805 single-family lots and commercial development. 1-4-11, This project is regulated in part by codes and ordinances administered by this Fire District relative to Contra Costa County Ordinance 89-65. If approved by your office, we request that the following be included as Conditions of Approval: SPECIFIC CONDITIONS: 1. The developer shall provide an adequate and reliable water supply for fire protection with a minimum fire flow ,based on the building size and type of construction. The required fire flow will be determined at the time two (2) complete sets of plans and specifications are- submitted to the Fire District. [10.301(c) UFC] If existing water supply does .not meet required fire flow . :for this development, structures shall be protected by approved automatic fire protection sprinkler systems. STANDARD CONDITIONS: 2. The developer shall be required to contribute Fire Facility Fees to mitigate Operational costs associated with increased. service demands throughout the Fire District. Fire Facility Fees are currently set at the rate of $488.00 per individual residential dwelling unit and $.30 per square foot of commercial development. C.C.Co. Com. Dev.. Dept. AB11-27 November 27, 1990 Page 2 The developer shall pay all required Fire° Facility Fees prior to the issuance of any building permit. 3. The developer shall submit two (2) complete sets of plans and specifications of the subject project, including any required built-in fire protection systems, to the Fire District for review and approval prior to obtaining building permits for construction to insure compliance with minimum requirements related to fire and life safety. [2.206 UFC] 4. The developer shall provide an adequate and reliable water supply for fire protection as set forth in the Uniform Fire Code. [10.301(c) UFC] 5. The developer shall provide fire hydrants of the East Bay type, as specified by the Fire District (and City Engineering Department) . Location of hydrants will be determined by the Fire District upon submittal of two (2.) copies of a tentative map or site plan. [10.301(c) UFC] 6. The developer shall provide access roadways with all-weather driving surfaces of not less than 20 feet of unobstructed width, and not less than 131- 611 of vertical clearance, to within 150 feet of all portions of the exterior walls of every building. Access roads shall not exceed 20% grade, shall have a minimum outside turning radius of 42 feet, and must be capable of supporting the imposed loads of fire apparatus (20 tons) . [10.207 (a) UFC] 7. Dead-end fire .department access roads in excess of 150 ,feet long shall be provided with approved provisions for the turning around of fire department apparatus. [10.207 (a) UFC] 8. Access roads and hydrants shall be installed and in service prior to combustible construction. [10.301(e) UFC] 9. Thd developer shall provide illuminated addressing located on all buildings in such a manner as to be plainly visible and legible from the street or road fronting the property. [10.208 UFC] C.C.Co. Com. Dev. Dept. AB11-27 November 27, 1990 Page 3 10. The developer shall locate trash enclosures such that commercial dumpsters are not stored or placed within five (5) feet of combustible walls, openings or combustible roof eave lines. [11.201(d) UFC] 11. The owner/developer shall apply to the Fire District for any permits which may be necessary to comply with Fire Code requirements. [4.101 UFC] 12. Where open space is to be maintained for public or private use, the developer shall provide access into these areas from public ways. These access ways shall be a minimum 16-foot width to accommodate fire department equipment. All openspaces, when left in their natural state, shall meet the Fire District's weed abatement standards. (10.207 (m) & 88.104 UFC) It is requested that a copy of the completed conditions of Approval for the subject project be forwarded to this office when compiled and adopted by the planning agency. If you have any questions .regarding this review, please contact the undersigned at (415) 757-1303. Sincerely, JOSEPH J. WHITENER Fire chief By:_ BILL BANOVITZ .9n Fire Inspect JJW:BB:ap Qt� cc: Robert Dal Porto Leo Mantelli A.J. Salomon C.C.Co. Building Dept./Soen Thung File (WS-90-7562-PD) DRAFT ' ENVIRONMENTAL IMPACT REPORT CYPRESS LAKES AND COUNTRY CLUB PROJECT County of Contra Costa, California ♦ cour� SCH # 92023048 DECEMBER, 1992 t ' DRAFT ENVIRONMENTAL IMPACT REPORT ' FOR THE CYPRESS LAKES AND COUNTRY CLUB PROJECT STATE CLEARINGHOUSE NUMBER SCH # 92023048 ' DECEMBER, 1992 PREPARED FOR: ' CONTRA COSTA COUNTY PREPARED BY: ' PUBLIC AFFAIRS MANAGEMENT 101 THE EMBARCADERO, SUITE 210 SAN FRANCISCO, CA 94105 rIN ASSOCIATION WITH: ABRAMS ASSOCIATES CHARLES M. SALTER ASSOCIATES WILLIAM SELF ASSOCIATES ' DON BALLANTI CONSULTING METEOROLOGIST ' INTRODUCTION The Draft Environmental Impact Report for the Cypress Lakes and Country Club project was made available for public review and comment on August 13, 1992. The East County Planning Commission held Public Hearings on the Draft EIR on August 31 and September 21, ' 1992. The comment period for the Draft EIR closed on September 28, 1992. Numerous comments were received from local residents, agencies and interested parties. The comments raised important issues to be addressed. To respond to these issues, the project applicant decided ' to revise the project application to provide additional information regarding the project design and mitigation features. Additional technical analyses were also conducted in the areas of geology and soils and hydrology in response to public comments. tThe County has determined that incorporation of the new information regarding the project application and additional technical analyses constitute significant changes to the Draft ' EIR. Therefore, the County has prepared this Second Draft EIR to allow public review and comment regarding the new information provided. The revisions to the Draft EIR focus are focused in the following areas: ' Additional information regarding landscape criteria, golf course maintenance, wetland habitat and mitigation plan, park land acreage and locations, and lake management plans. • Additional technical analyses conducted for excavation and levee construction and hydrology/flood hazards. Other sections of the EIR have been revised in response to comments from local residents, utility providers and local agencies. These revisions are provided to update and clarify the information presented in the Draft EIR. i DRAFT. ' ENVIRONMENTAL IMPACT REPORT FOR THE , CYPRESS LAKES AND COUNTRY CLUB PROJECT TABLE OF CONTENTS ' PAGE 1. PROJECT DESCRIPTION AND BACKGROUND ' 1.1 Introduction .1-1 1.2 Project Location and Existing Setting 1-1 , 1.3 Project Characteristics 1-4 1.4 Proposed Mitigation 1-8 1.5 Project Relationship to Relevant Plans 1-10 , 1.6 Discretionary and Other Agency 1-11 Approvals Required 1.7 Processing Approach 1-12 2. SUMMARY 2.1 Introduction 2-1 2.2 Project Description 2-1 2.3 Project Impacts and Mitigation Measures 2-2 ' 2.4 Alternatives Evaluated 2-3 2.5 Issues of Community Interest 2-3 3. DESCRIPTION OF ENVIRONMENTAL SETTING IMPACTS AND MITIGATION . O 3.1 Land Use, Planning and Public Policy 3-1 ' 3.2 Transportation/Circulation 3-28 3.3 Air Quality 3-64 3.4 Vegetation and Wildlife 3-76 3.5 Visual Quality 3-99 3.6 Noise 3-109 3.7 Hydrology and Drainage 3-118 3.8 Geology, Seismicity and Soils 3-147 3.9 Public Services 3-163 3.10 Utilities 3-189 3.11 Human Health 3-216 3.12 Cultural Resources 3-223 ' 3.13 Energy 3-232 ii , TABLE OF CONTENTS (continued) ' 4. ALTERNATIVES ' 4.1 No Project Alternative 4-2 4.2 Ranchette Alternative 4-5 4.3 Low Density Alternative 4-8 ' 4.4 Maximum Density Alternative 4-11 4.5 Off-Site Alternative 4-13 4.6 Commercial Alternative 4-16 5. OTHER CEOA SECTIONS ' 5.1 Significant Unavoidable Adverse Impacts Resulting from the Proposed Project 5-1 5.2 Cumulative Impacts 5-2 5.3 Significant Irreversible Changes 5-8 5.4 Growth Inducing Impacts 5-9 ' 5.5 Relationship Between Local Short-Tenn Use and the Maintenance and Enhancement of Long-Term Productivity 5-11 ' 6. REFERENCES/PERSONS AND ORGANIZATIONS CONSULTED 6-1 7. LIST OF PREPARERS 7-1 8. APPENDICES 8-1 Appendix A - Initial Study Appendix B.- Air Quality Methodology and Assumptions ' Appendix C - List of Species Observed During Field Surveys Appendix D - Wetland/Landscaping Information Appendix E - Geotechnical/Hydrology Information Appendix F - Will Serve Letter from Oakley Water District Appendix G - Will Serve Letter from Ironhouse Sanitary District Appendix H - Cultural Resource Appendix 1 LIST OF FIGURES Number Title Page ' 1.1 Regional Location 1-2 1.2 Project Site and Vicinity 1-3 , 1.3 Project Layout 1-5 1.4 Project Circulation 1-7 3.1-1 Other Planned Land Projects in the 3-4 , Bethel Island Planning Area 3.1-2 Census Tract 3010 3-6 , 3.1-3 Contra Costa County General Plan Land Use Map 3-10 3.2-1 Project Location/Traffic Analysis Study Area 3-29 3.2-2 Existing AM Peak Hour Traffic - Volumes and Level of Service (7:30 - 8:30 AM) 3-32 3.2-3 Existing PM Peak Hour Traffic - Volumes and Level of Service (4:30 - 5:30 PM) 3-33 ' 3.2-4 Existing Average Daily Traffic, 1992 3-34 3.2-5 Existing + Project AM Peak Hour Traffic 3-42 3.2-6 Existing + Project PM Peak Hour Traffic 3-43 3.2-7 Additional Traffic at the Project Entrance 3-44 3.2-8 Year 2000 AM Peak Hour Traffic - Volumes and Level of Service 3-46 r 3.2-9 Year 2000 PM Peak Hour Traffic - Volumes and Level of Service 3-47 3.2-10 Year 2000 Average Daily Traffic 3-48 , 3.2-11 Cumulative Traffic Forecasts. (ADT) and PM Peak Level of Service 3-51 ' 3.2-12 Roadway Improvements Required by the Project 3-58 3.2-13 Recommended Roadway Layout at Project Entrance 3-59 3.4-1 Vegetation and Habitat Map 3-78 3.4-2 Location of Wetland Areas on the Project Site 3-84 3.4-3 Location of Wetlands Impacted by the Project Site 3-91 3.5-1 Views of the Hotchkiss Tract 3-100 3.5-2 Views of Project Site and Sandmound Boulevard 3-102 ' 3.5-3 Views of the Delta Near the Project Site 3-103 iv ' LIST OF FIGURES (continued) Number Title Page 3.6-1 Noise Measurement Locations 3-110 3.6-2 Land Use Compatibility for Community Noise Environments 3-112 3.7-1 Existing Drainage Facilities in the Project Area 3-119 3.7-2 Proposed Drainage facilities 3-128 3.7-3 Proposed Levee System 3-131 3.7-4 Proposed Emergency Evacuation Routes 3-138 3.7-5 Typical Lake Cross-Section - Water Quality Control 3-142 3.8-1 Surficial Geology of the Project Area 3-148 3.8-2 Location of Faults in the Region 3-150 3.8-3 Map of Soils in the Project Area 3-153 3.9-1 Fire District Boundaries and Location of Sheriff Station 3-164 3.9-2 Location of School Facilities in the Project Area 3-175 3.9-3 Proposed Pedestrian and Bicycle Trails 3-184 3.10-1 Existing Water Wells and Facilities within the Project Area 3-190 3.10-2 Existing Oakley Water District Sphere of Influence 3-192 3.10-3 Existing Sewer Facilities within the Project Area 3-201 4-1 Off-Site Alternative 4-14 v LIST OF TABLES Number Title Page 1.1 Summary of Proposed Land Uses 1-6 2.1 Summary J P of Project Impacts and 2-4 � Mitigation Measures 1-1 Development Projects Pending , 3. op J g for Hotchkiss Tract 3-21 3.2-1 County Measure "C" Level of Service Standards 3-35 3.2-2 Existing Intersection Capacity Conditions 3-37 3.2-3 Cypress Lakes -.Vehicle Trip Generation 3-39 3.2-4 Cypress Lakes Trip Distribution 3-40 3.2-5 Volume/Capacity Ratios and Level of Service 3-49 3.3-6 (A) Projects That Would be Required by Cypress Lakes Itself 3-53 3.3-6 (B) Projects Planned for the Bethel Island Area 3-54 3.3-6 (C) Other Roadway Improvements 3-55 3.3-1 Federal and State Ambient Air Quality Standards 3-65 , 3.3-2 Air Quality Data for Bethel Island, 1988 - 1991 3-67 3.3-3 Emission Rates for Diesel-Powered Construction Equipment 3-71 3.3-4 Worst-case Intersection Carbon Monoxide Concentrations 3-72 ' 3.3-5 Worst-case Curbside Carbon Monoxide Concentrations 3-72 3.3-6 Project-Related Regional Emissions 3-73 3.4-1 Special Status Species Potentially Occurring , in East Contra Costa County 3-77 3.6-1 Summary of Noise Measurements 3-111 , 3.6-2 Noise Levels at Project and Off-Site Residences for Various Scenarios 3-114 3.8-1 Active Fault Data 3-151 3.8-2 Results of Piezometer Testing 3-155 3.10-1 Project Water'Consum tion 3-196 ' P A r1. PROJECT DESCRIPTION AND BACKGROUND ' 1.1 INTRODUCTION An initial study was prepared on the proposed project that was submitted prior to February 6, 1992 (the date of the Notice Of Preparation [NOP]). The NOP noted that the project application may be amended during the process in response to environmental issues and concerns raised. Any amendments to the application submitted prior to completion of this EIR are addressed herein. Subsequent amendments to address remaining concerns covered in this EIR and/or the planning process may be necessary. The application was in fact revised to address comments raised in response to the NOP, first DEIR, neighborhood and agency concerns and the finalization of preliminary environmental reports. The major revisions to the application include: 1.) greater preservation and enhancement of wetlands 2.) accommodations for a more effective and efficient drainage system 3.) elimination of neighborhood commercial uses 4.) the relocation of the potential school site ' 5.) more efficient internal circulation system 6.) preservation of cultural resources ' 7.) additional hydrology and geotechnical analysis ' 8.) additional landscape plans The revisions to the proposed project do not raise new possible environmental impacts that were not raised by the original project, negating the need for a new initial study. In fact, the revisions will lessen some of the potential impacts of the original project design as identified in the initial study. All potential significant impacts of the proposed project, as revised, are addressed herein. 1.2 PROJECT LOCATION AND EXISTING SETTING The Cypress Lakes and Country Club project site is located in the Sacramento-San ' Joaquin Delta area of unincorporated north-eastern Contra Costa County, approximately 2.7 miles east of the Town of Oakley (see Figure 1-1). The project site is located in the 'off-island" portion of the Bethel Island Area, commonly known as the Hotchkiss Tract. The project site is ' located at the junction of Cypress Road and Bethel Island Road (see Figure 1-2), and is generally 1-1 1 - r t t . t Sacramento 99 80 Napa 12 t O 160 p�ntioch t y.• so Stoc 101 •': :j a QConCotd ct a O :•�-. P=oke ASe .1••`j 24 660 20 San•j�='�`' � sao Cisco 'Frail. SS 8g 101 • .;�• sail Figure 1.1: • . ,•? Location . Regional t COUNTRY CYPRESS iAB RO1ECT t CL 1-2 Lu ell r — o J c rte_} !� a' t Q S U Fit .r ..- S i `¢� � +ti RS ? S c+ t .:....y...4 ZF. • '� � A� It�-rti'-T'ry. _ __ .atl aPrJB — ^";•.: _:J •DY r .�.- 0- Y c �.. .Q ^=n alrn lamas AYMNDix Now- _ •a as- ti°t�' //.'''� PD tPn-4 Mlai . Ar — o` � x7slxPixY.. aO oa �a'•- 3 of n 'xl Yrnua . aMYrsi 3AI Stl1,135 lar o .•'901115 0 ...•a3 y. ..q:�,.; g rt1 _ � 'OA7P h /flxlYM O t �F: a •i'.'i t'l_._, '18 ]x4 1; `• 4�y- '•-'.',� tff o YYma +,3ar YLOS1YY:n saY a YlItl7 - w - .:1QI !/l-..`::•C....'.j: .aJ. I�� sjt a ..otl ii ld x i ,-rrrD3 B.x,ti. as a1fA0Y�%�� BY nitla aYK �•\. a=il � _��".t. }ar . t � , aT3VA "i1Y� wA law '�V \ ' �`, x •!Sr Y. AVM W ift', Is t !IV �. !".j j• ':,- � l�� ��r is t-.._. -:T..'..i�� .- _-I � m � S - �y ,`•+ . 51 !' 31� >i� 'r1.I��R. ,F.7 �� .?tkk`:•�,='�' ,is N :€ �i• � b•r'F.O Wt : N :h aFf' �'. ACwt-cTYe `ralA- - __ - _•y - •�\.p�- "`:e ! �'' ^ ,.��, 1 aft': e," .�.•t -���a �"� • y I , ' a 2....—- ""'t"'� -'--t- ... �-aro Y .�''�.;,.,C'/'�- --•• o?... .,;1�. 7µ; `,.Z`§.'� ^ ti i 1 .�"•: 'Td•x W ."'7 V} Yarm,uxayrn ag 1`__?:_1 -_„'1 IC•r `�.,'.n' ffj [W_, W. Y n bordered by Bethel Island Road on the west, Sandmound Boulevard on the north and east and , by agricultural uses on the south. The existing use of the site is agricultural (cattle grazing) and consists of several fenced ' pasture areas, with irrigation and drainage canals crossing the property in various locations. A few homes and agricultural structures are located on the project site. These structures are , primarily located along the unimproved portion of Cypress Road and east of Bethel Island Road. 1.3 PROJECT CHARACTERISTICS The Cypress Lakes and Country Club project would be constructed on approximately 685.9 acres consisting of seven parcels. The project would consist of 1,330 single-family , residential units. In addition, the project would include'an 18-hole golf course with amenities, an internal levee system, a man-made lake and channels, a day care facility, parks, a fire station, beach club, and a potential school site (see Figure 1-3). The project would be constructed in phases. The phases would be timed to coincide with necessary infrastructure improvements (i.e. sewage, storm drainage, water facilities, roadway improvements, etc.). The first phase would include basic grading of the site and excavation for the man-made lake and channels. Material excavated for the lake and channels would be used to construct a levee system around the project site for flood protection. The levee system would require Federal Emergency Management Agency (FEMA) approval before any home constructed on the site ' could be occupied. Preliminary grading for the golf course would occur coincident with levee construction. The proposed residential development would be on lots ranging in size from ' approximately 5,000 square feet to 10,000 square feet. Residential lot densities would average approximately 5.4 units per acre. The overall density of the project is 2.21 units per acre. Residential development on the southern portion of the site (south of Cypress Road) would be oriented toward the man-made lake of approximately 60 acres. Non-motorized boats , would be permitted on the lake. A beach club would also be developed adjacent to the lake to provide recreational opportunities for project and area residents. The beach club would provide a swimming facility adjacent to but separate from the man-made lake. In addition, a day care center, fire station,.potential school site and public park would be located in this portion of the project site. , The residential development north of Cypress Road would include an 18-hole golf course interwoven among the various neighborhoods. A clubhouse facility, driving range and , maintenance facility would also be located in this area as well as several water channels. Commercial uses on the site are no longer proposed. 1-4 r 911180 puB puvl paaala-eu0 :aoanoS lasroad Sf to AHINf10o saxrl SSMAD .-- ------------------------ % — -- -------------- 7115 / — — -------- % \1ING / � — — �!"—�`� \ Z> 1 ;'Ilill'I"al;llllil;li Iilll IIIII!iilllll!!; :;!�'! !11;!!;1'11 118!1•.!;!;!; 1111!•' q { 1ilj;ili!II!,!!!;!I!!1;1!I'1i:il!;i;i!i!!!11!11in'i!ri�l{i1i1i;i1i1i111 11 ta! i!: I { lj;i;i;?'��111iiili,liiiioill 111,1:1!1!li'!;!!i!11111111!i'il I j'illli?''''''!'!j'jlii, 'ti111;:. 1 1 MIS 'I'll!! 1:111jl .;.II"' !Ijj jii;il;1i11jj!n11!1!11 1j11 100FgS I I 'llllillill'I"• ',:1;:1111111 oi11n!j111�'!''�111!' 11.1111"1111;1; `�\ `�` 3L6 3V ;114,• !i'iiij!ilii'!i!Iliiriljlrii''i!iiiirrrrrl'rri!rrr d I—— ('dU) 33A31 "i i;! "'iii;iii;1111111;l;i;11111;iiiii;iii;i!i!�ji!i'iiiiljjii; �1 �� qnd / ".!'If!;: •!!'.;i'!!!,y'Y!'!�I!I�:;!�;i;i;�jl�II'r11;1G!'r;l'I';. yo ''� / I I :1;;;;; •1;;i;i!i;Jiii;i!!I!!iA!!II!ii;;!ii;l�!!i;i!!i!!!. � ��` / I laud !;i;: V 'I!::,!�;!;•,:!,,!4;!;!;:!;!i: / MIS LON OVON i'illlj111j1! dvN 31r SS3NdA3 111aa 1MVd V ION m NI { 11!11;111 iili�: �� I I iI O :j. ! ce lj AVAkMVA I I Q J 33LLOVEld ' (n Voll r 30VVDIS �AllW V 1— \ \ ' ••� 315 •�!::� :_�.::.. , \ ';i;ilil!tiIH ' I W 3S11DNam { � I 111 I ;I T1111� � I I I I I I I I I 1 I I I I !!1:111 I 33A31 01 i 111111:1 ( 1i11!1;i'� u I I \ I ON ys The project design would avoid most of the existing seasonal wetland areas (6.52 acres) and waters of the U.S. (2.66 acres) present on the project site. However, approximately 0.75 acres of wetlands would be impacted by the proposed project. The project design would include replacing the impacted wetlands through restoration and enhancement of existing wetland habitat on the project site. The major land uses proposed by the project, including approximate acres of coverage, are summarized as follows: TABLE 1-1 SUMMARY OF PROPOSED LAND USES Land Use Acres Single-family Residential (1,330 units) 242.9 Fire Station 2.0 School Site 7.4 Beach Club 1.9 Daycare Center 0.5 Roadway Right-of-Way 74.6 Lake/Channels 61.0 Parks 33.7 Golf Course 170.3 Existing Wetlands 6.5 Levees 54.6 Levee Road 9.0 Drill Sites 10.5 Wetland Mitigation/Buffers 11.0 TOTAL 685.9 The primary en to the site would be via Cypress Road at its intersection with Bethel trance YP Island Road. A secondary access would be provided via Sandmound Boulevard at the north end of the project site. Cypress Road would be extended through the project site as the primary collector roadway. Residential neighborhoods would be accessed by an internal road system consisting of primary roads, secondary loops and cul-de-sacs to provide access to the individual neighborhoods (see Figure 1-4). In addition to the above mentioned facilities, the proposed project would also include various storm drainage, water system, sewage disposal and public utility improvements. On-site storm drainage improvements would include curbs, gutters and drain inlets to an underground conduit system which would be designed in accordance with Reclamation District 799 (RD-799) and County standards. The proposed system would pump excess runoff into Sand Mound Slough. The project would include on-site detention of storm water in the proposed lake and 1-6 I ' 1 , 1 I I , 1 1 , 1 , I 1 1 I I 1 I I 1 � I I CIRCULATION ROUTES 11 i' I , I 1 I 1 I�1 � 1 I - 1 1 W d d � I 1 I � i � (PR SSF1 ROgp � i I 1 I I 1 7i 1 1 , I Y j 1 I 1 j ' , t 1 1 � 1 1 , 1 , 1 , 1 1 \ I CYPRESS LAKES Figure 1-4:& , COUNTRY CLUB Project Circulation PROJECT Source: Chartered Land and Cattle , 1-7 i . channel detention facilities. On-site sewage facilities would include a gravity sewer system, lift stations and pumps. Sewage from the site would enter the existing force main in Bethel Island Road. To provide water to the site, off-site improvements including transmission lines from Highway 4 at Cypress Road would be provided. On-site water facilities would include 6", 8" and 10" underground distribution pipelines. Other utilities, such as electricity and solid waste disposal, would be provided by existing service providers. 1.4 PROPOSED MITIGATION The proposed project has been designed to reduce certain impacts through the incorporation of the following measures: Levee System: The project design includes construction of a levee system around the project site to remove the proposed development area from the flood hazard zone. The levee system would be certified by FEMA prior to the construction of houses on the site. Storm Drainage Improvements: The project includes a system of channels and lake to provide stormwater detention on-site to reduce drainage impacts on RD-799 facilities. Water Quality Management Plans: The project includes innovative water quality management strategies to maintain acceptable water quality in the project channels and lake. Management strategies include the use of specific plant species to remove pollutants from the water and mechanical circulation of water to improve flushing action. Wetland Mitigation Plan: Thero'ect would impact 0.75 acres of the 9.18 acres of P J P wetlands on the site. The project would include the replacement of impacted wetland through the enlargement and enhancement of existing wetlands on-site. The 0.75 acres impacted would be replaced with approximately 2.75 acres of wetland. Ground Subsidence Monitoring Plan: The project includes measures to monitor ground subsidence that may result from de-watering activities associated with construction of the project levees, channels and lake. Monitoring wells and settlement plates would be used to monitor construction. If groundwater levels or soil subsidence exceeds acceptable levels, construction activities would be stopped and remedial actions taken. Landscape Plans: The project includes detailed landscape plans for the project levee and common areas. The landscape plans include lists of•desirable plant species, irrigation techniques and other landscape criteria. Additional landscaping would be provided around the project perimeter outside the levee along Sandmound Boulevard and Bethel Island Road to reduce visual impacts on adjacent residents. Channel Enhancement Plan: The project includes plans to enhance the primary drainage ditch ("main drain") into a channel of approximately 8.0 acres in size. A new channel is also proposed in the north/south direction and would connect to the proposed lake. The 1-8 second channel would be approximately 110 acres in size. The channels are proposed to provide additional riparian habitat and visual interest to the project. The banks of the channels would be sprigged with willow and cottonwood cuttings to provide riparian cover. Energy Conservation Guidelines: The project is proposing. to maintain a goal of exceeding the energy efficiency standards of Title 24 by 10%. This would be achieved through the incorporation of design features into each home to reduce energy consumption. Provision of School Site: To help mitigate the project's potential.impact on local school facilities, the project plans include the dedication of a 7.4 acre school site on the project , site. The school site would be dedicated to the Oakley Union Elementary School District for the construction of a new elementary school in the Bethel Island area. Provision of Fire Station Site and Facility: The project plans include a 2 acre site for a new fire station on the project site. The fire station is located near the project entrance at Cypress Road and Bethel Island Road. The project would also include construction of ' a new fire station facility on the site. Provision of a fire station on the project site would improve fire protection.services for Hotchkiss Tract and the Bethel Island area. Preservation of Cultural Resources: The project plans have been developed to avoid culturally sensitive areas present on the project site. Portions of the project site known to contain cultural resources have either been avoided or are proposed for less disruptive uses such as parks and playgrounds. Provision of Parks/Recreational Amenities: The proposed project includes approximately 1 33 acres of public and private parks primarily located south of the proposed extension of Cypress Road. In addition, other recreational amenities are being proposed including: a lake, golf course, beach_club, trails, and open space corridors. Affordable Housing Fee: The project applicant has agreed to pay a in-lieu affordable housing fee equal to $3,333 per residential unit. For the proposed project this fee would generate approximately $4,432,890 for the County's affordable housing programs. These fees would be paid at the time of issuance of building permits. As an alternative, the project applicant may construct a portion,.or all, of the affordable housing units on-site. , Homeless Fees: The project applicant has agreed to pay an in-lieu fee to the County's Homeless Trust Fund. The amount of this fee would be determined by the County and paid upon issuance of building permits for the project. 1-9 1.5 PROJECT RELATIONSHIP TO RELEVANT PLANS Contra Costa County General Plan, As Approved January, 1991 The Cypress Lakes and Country Club project is located within the County Urban Limit Line, which would allow development in accordance with General Plan policies and the 65/35 Land Preservation Standard. The Contra Costa County General Plan Land Use Map designates the area as Agricultural Land (AL) and Open Space (OS); with an overlay designation of "Off- Island Bonus Area" which allows increased residential densities under certain circumstances. The Contra Costa County General Plan states the following with regard to residential development within the Off-Island Bonus Area (page 3-29): ' A bonus density is identified in the "Off-Island" area of the Bethel Island Planning Area east of Jersey Island Road. The base density of this area is 1 dwelling unit per 5 acres. This density shall be increased through the bonus program if the applicant participates in one of the following programs: Recreational Proiects. Residential projects which include a distinct, identifiable recreational character by including substantial recreational facilities shall be allowed a density of 1.0 to 2.9 units per net acre. Recreational amenities may include marinas or launching areas off the project site on Sand Mound or Rock Sloughs, a lake community, a sailingiboating club on a project lake, an equestrian facility, a tennis club, or a golf course. Purchase of Development Rights. The development rights for one acre increments of land in the County with an Agricultural Land designation may be purchased and dedicated to the County to increase the base density up to 1/2 dwelling unit per net acre. Acquiring development rights in one acre increments of land in the County with an Agricultural Core designation will increase the base density up to a maximum of 3 dwelling units per net acre. A program for acquisition of development rights shall be implemented by the Community Development Department. Within the Off-Island Bonus Area, the General Plan limits new development to 3,000 primarily recreation-oriented units. Of this total, 153 units have been approved but are not.yet constructed, leaving a balance of 2,847 allowable new units. The proposed project's 1,330 residential units would fall below this limit. Two additional applications for projects within the Off-Island Bonus Area have been submitted, for a combined number of 1,653 residential units. These projects, when combined with the Cypress Lakes project, total 2,983 units which exceeds the remaining number of allowable units by 136 units. However, the latter two applications are not being actively pursued (Contra Costa Community Development Department, July, 1992). The proposed project includes an 18-hole semi-private golf course, parks (20 acres for a neighborhood park and 6 acres through-out the project, a swim and tennisibeach club, and lake 1-10 and channels designed to meet the recreational character requirements of the ContraCosta County General Plan for increased residential density within the Off-Island Bonus Area., In addition, the project has an overall residential density of 2.21 units per acre (Gross Acreage - public and private easements _ # of dwelling units) which falls within the 1.0 to 2.9 units per acre. No purchase of agricultural development rights is proposed. Bethel Island Area Specific Plan, April, 1991 i The validity of the Bethel Island Area Specific Plan (BIASP) and its EIR were challenged by various environmental groups. The Court of Appeal has declared the BIASP and its EIR invalid. Subsequently, the County, project applicant and environmental groups entered into a settlement agreement requiring the recision of the Bethel Island Specific Plan, decertification of its EIR, and vacation of the existing development agreement between the County and the project applicant. Therefore, this EIR does not address conformity with the Bethel Island Specific Plan. The settlement agreement, December, 1992, established a framework whereby the parties have agreed to work together in processing applications on the project site. 1.6 DISCRETIONARY AND OTHER AGENCY APPROVALS REQUIRED The project applicant has applied for the following discretionary approvals by Contra Costa County for which this EIR is intended to cover: • Rezoning of 685.9 ± acres of land from General Agricultural District (A-2) and Heavy Agricultural District (A-3) to Planned Unit District (P-1); • Preliminary development plan approval for the proposed club house, beach club house, beach club, public park, maintenance facility, and other uses not in the final development plan; • Final development plan approval for the proposed residential uses, golf course/driving range, wetlands, lake, channel and levee; • Vesting tentative map to subdivide the 685.9 ± acre site into 1,330 single-family lots; • Design review of the project. Other approvals and/or permits will be required to fully implement the project. This EIR , is intended to cover all those necessary approvals and/or permits which may include but are not limited to the following: 1. LAFCO Approval - LAFCO approval may be needed for the reorganization of the Sphere of Influence and annexation of the project into the Oakley Water District 1-11 i and Contra Costa Water District for provision of water; the Ironhouse Sanitary District for sewer; and possible consolidation of the Oakley and Bethel Island Fire Districts in the Bethel Island Planning Area. Other annexation and/or possible consolidation may be necessary for other services. 2. Financing and Maintenance Districts - The establishment of a park maintenance district, landscape and lighting district, geologic hazard abatement district, or other special districts for the financing and/or maintenance of infrastructure and other improvements. 3. National Pollutant Discharge Elimination System (NPDES) Permits - May be required for drainage discharge. 4. Section 404 Permit - The applicant will need to qualify for a permit under Section 404 of the Clean Water Act for the filing of any wetland areas on-site.. 5. FEMA Approval - Approval will be sought for the internal levee. 6. Development Agreement - The applicant will request approval of a development agreement with the County to establish the terms and conditions under which the ' project will be developed. 7. Streambed Alteration Permit - The applicant will be required to obtain a streambed alteration permit from the Department of Fish and Game. This list is not intended to be exhaustive. Other approvals and/or permits may be necessary to fully implement the project objectives which this EIR is intended to cover. 1-12 2. SUMMARY 2.1 Introduction An initial study was prepared on the proposed project that was submitted prior to February 6, 1992 (date of the NOP). A Draft Environmental Impact Report for the Cypress Lakes and Country Club project was made available for public review and comment on August 13, 1992. The East County Planning Commission held Public Hearings on the Draft EIR on August 31 and September 21, 1992. The comment period for the Draft EIR closed on September 28, 1992. Numerous comments were received from local residents, agencies and interested parties. The comments raised important issues to be addressed. To respond to these issues, the t project applicant decided to revise the project application to provide additional information regarding the project design and mitigation features. Additional technical analyses were also conducted in the areas of geology and soils and hydrology in response to public comments. The County has determined that incorporation of the new information regarding the project application and additional technical analyses constitute significant changes to the Draft EIR. Therefore, the County has prepared this Second Draft EIR to allow public review and comment regarding the new information provided. 2.2 Proiect Description The Cypress Lakes and Country Club project site is located in the Sacramento-San Joaquin Delta area of unincorporated north-eastern Contra Costa County approximately 2.7 miles east of the Town of Oakley. The project site is located in the "off-island" portion of the Bethel Island Area, commonly known as the Hotchkiss Tract. The project site is located at the junction of Cypress Road and Bethel Island Road, and is generally bordered by Bethel Island Road on the west, Sandmound Boulevard on the north and east and agricultural uses on the south. ! The existing use of the site is agricultural (cattle grazing) and consists of several fenced pasture areas, with irrigation and drainage canals crossing the property in various locations. A few homes and agricultural structures are located on the project site. These structures are primarily located along the unimproved portion of Cypress east of Bethel Island Road. The Cypress Lakes and Country Club project would be constructed on approximately 685.9 acres consisting of existing parcels of land. The project would consist of 1,330 single- family residential units. In addition, the project would include a 18-hole golf course with - amenities, a swim and tennis club, a man-made lake and channels, a day care facility, parks, a potential school site, and a fire station. The proposed residential' development would be on lots ranging in size from approximately 5,000 square feet to 10,000 square feet. The overall residential lot density is approximately 5.40 units per acre (1,330 units on 246 acres). The overall density of the project 2-1 is 1.44 units per acre (1,330 units on 685.9 acres). Residential development on the southern portion of the site (south of Cypress Road) would be oriented toward the man-made lake to provide a lake-front living environment. A swim and tennis club would also be developed in this area to provide recreational opportunities for project and area residents. In addition, a day care center, park, fire station and potential school site would be located in this portion of the project site. The residential development north of Cypress Road would include a 18-hole golf course ! interwoven among the various neighborhoods. A clubhouse, driving range and storage maintenance facility would also be located in this area as well as several water channels. The proposed project has been designed to reduce certain impacts. The primary mitigation measures incorporated into the project's design include: • Internal Levee system around the project to remove the project site from the 100-year flood hazard zone • Storm drainage improvements including on-site detention facilities • Water quality management plan • Wetland mitigation plan • Ground subsidence monitoring plan • Landscape plans • Channel enhancement plan • Energy conservation guidelines • Provision of a school site • Provision of a fire station site and facility • Preservation of cultural resources • Provision of parks and recreational amenities • Payment of affordable housing fees • Payment of homeless fees 2.3 Proiect Impacts and Mitigation Measures The evaluation conducted for this report included an examination of the environmental impacts associated with the Cypress Lakes and Country Club project and those measures that could reduce the identified impacts to insignificant levels. The project impacts and corresponding mitigation measures are summarized in Table 2-1. The significance of each impact is noted along with the required or recommended mitigation measures. The significance of each impact with and without implementation of mitigation proposals is also noted. The following impact categories are used in Table 2-1: (B) beneficial impact; (NS) not significant impact; (PS) potentially or possibly significant impact (an impact which cannot be precisely assessed at this time) and (S) significant adverse impact. 2-2 2.4 Alternatives Evaluated Chapter 4 of the EIR describes and evaluates six alternatives to the proposed project. These alternatives include: • No Project Alternative • Ranchette Alternative • Maximum Density Alternative • Low Density Alternative • Commercial Alternative • Off-Site Alternative The analysis of alternatives evaluates how each alternative would either avoid,,reduce,or in some cases worsen, potential impacts when compared to the proposed project. This comparison between the project and the alternatives allows the public and decision makers to clearly understand comparative merits of the alternatives. This approach to the analysis of alternatives to the project is consistent with the CEQA Guidelines Section 15126(d). 2.5 Issues of Community Interest Several issues of community interest were identified during the public review period for the first Draft EIR,these include: improvement of the existing RD-799 levee system,construction of an internal levee system and the potential channelizing of floodwaters along Sandmound Boulevard in the event of levee failure or overtopping, potential ground subsidence due to groundwater extraction and construction of project lakes, impacts to the visual character of Hotchkiss Tract, increased traffic and related noise and air quality impacts, impacts to plant and animal life, increased storm water runoff and impacts on local schools. 2-3 TABLE 2-1 SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES (Note: impacts are in summary form only;please refer to specific topic headings for details.) IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) 3.1 LAND USE, PLANNING AND PUBLIC POLICY a. The project would add 1,330 dwelling units to the The project will pay a in-lieu affordable housing fee , existing housing stock in price ranges between equal to $3,333 per residential unit. This fee should $175,000 to $400,000. The number of new units is be paid at the time of issuance of building permits for below the 2,909 new units allowed by the General the project. As.an alternative to the fees, the project Plan. The project is consistent with the General Plan applicant may construct a portion or all of the policy that development projects should be at or near affordable housing units on-site. If this alternative density maximums to provide as much housing as mitigation is selected, the location and design of the possible. The project would contribute in-lieu fees affordable housing units should be submitted to the for affordable housing of $3,333 per dwelling unit County for review and approval prior to filing a final constructed, and in-lieu fees for the County's subdivision map.(3.1-1;B) , homeless fund.` The project applicant may consider providing all,or a portion,of the project's affordable housing requirement on-site by designating and constructing affordable units as part of the project. (B) b. Because the proposed project is predominately The project marketing should be oriented toward residential, the project would result in a short-term seniors and retired people to reduce commute traffic unavoidable impact on East County's existing from the project. The project's impact on East Jobs/Housing imbalance (S) County's Jobs/Housing imbalance would still remain an unavoidable short-term impact. (3.1-2;5) c. The project would be required to pay the County's Protection Fee shall be paid for each residential unit Protection Fee as well as in-lieu contribution to the within the project to acquire development rights on County Homeless Trust Fund. (B) agricultural land (and open space or wetlands areas) or to provide financing for farmers to continue agricultural production. The fee shall be determined by the County and paid upon the issuance of building permits for the project. (3.1-3) The project will pay an in-lieu contribution to the County Homeless Trust Fund. The amount of the contribution will be determined by the County and paid,pro-rata, upon the issuance of building permits. (3.1-3; B) 2-4 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) 3.2 TRANSPORTATION/CIRCULATION a. The addition of project traffic to the street network Road Improvements at Project Entrance-Construct a would substantially change traffic volumes on Cypress new intersection at Cypress Road and Bethel Island Road between the project and Highway 4. Beyond Road, and on the approaches to this intersection. this location, traffic from the project would be more Widening should extend 1,000 feet in each direction. dispersed,but would still have a significant impact on To properly accommodate the proposed project traffic Highway 4 between Oakley and the State Route 4/160 as well as future traffic from other parts of the freeway. The traffic analysis assumed that portions of Specific Plan area, the intersection will have the lane Cypress Road would be widened. All other requirements shown on Figure 3.2-13. The south- intersections were calculated for capacity conditions bound approach will be widened with one more lane. without any additional roadway mitigation measures. This intersection shall be designed so that it can During the AM peak hour, all intersections would ultimately be consistent with a future extension to operate at a satisfactory LOS with the existing plus Byron Highway south of the intersection. Cypress project condition. PM peak hour traffic will also Road will cross the levee just east of the entrance to operate at satisfactory traffic conditions,assuming that the project. The vertical curvature of Cypress Lakes partial improvements are constructed on Cypress Road where it crosses the levee shall be submitted Road. One other intersection would be critically prior to final map approval. A 45 mph design speed impacted. At Neroly Road and Highway 4 (Main would be desirable. This project would include the Street), traffic conditions would change from LOS installation of traffic signals that would be put into "D" to LOS "E". Mitigations are planned for this operation at the time that volumes meet Caltrans intersection as a part of the ONBAG Program, traffic warrants. This is estimated to occur when the including widening the northbound approach to project has about 500 units completed and occupied. provide two left tum lanes. This improvement would (Note: this improvement could impact cultural restore the intersection LOS to "D. The project will resources) (3.2-1) add significant traffic volumes to the roads in the immediate vicinity of the project. As a direct result Bethel Island Road and Sandmound Boulevard - of the project, Cypress Road will exceed capacity. Bethel Island Road is planned to ultimately become a These roads will require reconstruction and widening four-lane divided roadway between Cypress Road and at the time of project construction. (PS) the Bethel Island Bridge. This widening is not necessary as a result of the project, but there are interim improvements that should be accomplished. At Sandmound Boulevard, the intersection should be improved and widened, and left tum lanes should be constructed. Sandmound -Boulevard should be realigned to a right-angle intersection at Bethel Island Road. This project would also include the installation of traffic signals that would be put into operation at the time that volumes meet Caltrans traffic warrants. This is not estimated to occur as a result of the project itself, but would be needed as a result of 2-5 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) development being completed on Bethel Island. Sandmound Boulevard should be improved along the northern boundary of the project. (3.2-2) Cypress Road Widening - Complete the implementation of the Cypress Road widening from Machado Lane to east of Knightsen Road. This roadway improvement should be in place before 1000 units are occupied at Cypress Lakes.It would include the installation of traffic signals at Sellers Road and Knightsen Road that would be put into operation at the time that volumes meet Caltrans traffic warrants. The widening of Cypress Road between Knightsen Avenue and Bethel Island Road should occur before occupancy of the Lesher Landing project or any other project that adds over 25 units in this part of the Bethel Island Area. (3.2-3) Sandmound Boulevard Improvements - This project would reconstruct, at a minimum, one-half of Sandmound Boulevard from Bethel Island Road along the north border of the project. The remainder of Sandmound Boulevard improvements should be done in conjunction with other developments along Sandmound Boulevard. (3.2-4) Conformance with Measure C - The Cypress Lakes project would satisfy the requirements of Measure C by constructing the roadway improvements listed in Table 3.2-6(A). The project may also be required to pay a regional traffic fee for Measure "C" projects. This fee has not been established and is currently being evaluated by TRANSPLAN and the CCTA.The payment of these fees will help to mitigate the regional traffic impacts-of this project.(3.2-5; NS) b. The 1,330 houses proposed would generate 10,287 Bus Transit Service-While there is no current transit vehicle trip ends per day, including 730 trips-during in the area, it can be expected that daily bus transit the AM peak hour and 1,036 trips during the PM service, provided by Tri-Delta Transit, would be peak hour. Trip generation for the various other provided to the Hotchkiss Tract and Bethel Island project components, including the golf course and Area when a significant amount of the development . 2-6 ' TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) clubhouse, were estimated based on previous studies in the area has been built and occupied. The situation of similar facilities. (PS) should be monitored, and transit service should probably be started when about 1,000 homes have been completed in the area. This bus route could be an extension of Routes 383 and/or 384 and would follow Cypress Road and Bethel Island Road to a terminal stop on Bethel Island. (3.2-6) Participate in County TDM Program - The project would be required to comply with the County residential TDM Ordinance, the County Growth Management Program,and the Bay Area Air Quality District regulations regarding transportation. TDM requirements of the County include the preparation and distribution of a TDM information program that could include the provision of maps showing available transit routes, and information on ridesharing and vanpool services to prospective home buyers. These types of measures can be expected to have only a relatively small impact on reducing peak hour trips. Other studies have shown that TDM actions applied to a residential development can reduce the number of single occupant auto trips by 3-5 percent during the commute peak hours. (3.2-7; NS) r r - f r 2.7 r r TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) c. The internal circulation system of the project Design level plans for the project entrance on should be modified to provide improved circulation Sandmound Boulevard should be prepared and and conformance with future development in the submitted to County Public Works Department for Bethel Island Area (PS) review and approval prior to approval of the first phased subdivision map. The design level plans should provide for:adequate transition from the levee cross-section to grade at Sandmound Boulevard; adequate stopping distance;and adequate corner sight distance. (3.2-8) Provide a right-of-way for a future -roadway connection to the property south of Cypress Lakes, and construct the road up to the edge of the levee. This property could develop into a residential neighborhood,and should desirably be connected into Cypress Lakes at some time in the future, especially for school trips and other internal recreational trips. However, such a roadway connection should not be the only access to this new area, and should be provided only after Bethel Island Road is extended south across Rock Slough. This road should be treated as a secondary connection,so that it will limit the amount of through traffic that would travel through the Cypress Lakes development. (3.2-9) Provide a road extension of Cypress Road through the project to connect to Sandmound Boulevard. Certain residents on Sandmound Boulevard have protested this connection for the reason that they expect traffic from Cypress Lakes to impact their quiet residential streets. This connection would allow for more convenient access for existing residents, providing a connection to the future school site, and easy access to Cypress Road through the project. (3.2-10; NS) d. There are few bicycle pathways in the Bethel Provide a major bicycle path within the project on Island area. The existing width of Cypress Road is Cypress Road between Bethel Island Road and approximately 24 feet with no sidewalks or other Sandmound Boulevard, and on Cypress Lakes Drive provisions for pedestrians. Other streets in the study through the project. This pathway should be designed have similar cross-sections. The project will increase to County standards. (3.2-11) pedestrian and bicycle traffic.(PS) 2-8 i TABLE 2.1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) At such time as other roadway improvements are completed, complete other bicycle paths as required. This would include a pathway along Bethel Island Road on the west boundary of the project,a pathway along Rock Slough on the southern boundary of the project, a path along the Byron Highway Extension, and a pathway along Sandmound Boulevard on the north and east boundaries of the project. (3.2-12;NS) e. Traffic generated by Cypress Lakes will contribute Intersection of Neroly Road and SR 4 (Main St.) - to cumulative traffic, and the project would be Widen the northbound approach to provide a double required to help mitigate these impacts by paying the left turn from Neroly to SR 4. This will improve the Subregional Road Fee. Most of the traffic impacts of V/C ratio from 0.93 ("E") to 0.81 ("D"). This will the short-term cumulative traffic can be mitigated to reduce this impact to a less than significant level.The an insignificant level. However, there are two Project traffic will amount to about 10 percent of the exceptions. The following mitigation measures traffic growth that is projected at this intersection. should be addressed by the Cypress Lakes project if The project applicant should pay a fair-share the Delta Expressway is not implemented, and if the contribution equal to 10% of the cost of the problem is not mitigated by other sources.(PS) improvement. (3.2-14) Intersection of Cypress Road and SR 4 - Widen the southbound approach to provide a double left turn lane for traffic from SR 4 to Cypress Road, and widen Cypress Road on the east leg of the intersection. This will improve the V/C ratio from 0.87 ("E") to 0.79 ("C"), and will reduce this impact to a less than significant level. The need for this improvement will depend entirely on the pace of development and the timing of the construction of the Delta Expressway. If the Cypress Corridor development'moves quickly to implementation,prior to the completion of the Delta Expressway, this mitigation will be required. The need for this improvement will be reduced if the Laurel extension is completed, and the Laurel Avenue connection to the Delta Expressway is completed. Traffic from the Cypress Lakes project will amount to about 25 percent of the traffic growth that is projected at this location. The applicant should be required to pay a fair share fee equal to about 25% of the cost of this improvement. (3.2-15) 2-9 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) Traffic generated by the Cypress Lakes project will contribute to long-term cumulative traffic. In particular, the Cypress Lakes Project will have a cumulative impact on SR 4 in the freeway section ' between Bailey Road and Highway 160, and on the arterial section between Highway 160 and Cypress Road. The Cypress Lakes project will assist in mitigating these impacts by paying the subregional road fee. As a result, most of the traffic impacts of the long-term cumulative traffic appear to be mitigated to an insignificant level. (3.2-16; NS) f. Construction of the proposed project would result Contra Costa County has standard restrictions on in additional truck traffic on Cypress Road and SR4. construction activities regarding hours of operation, (PS) noise and dust control. Additional mitigations could include restrictions on heavy trucks from SR 4 during the commute peak hours. The project could normally be required to assist in maintenance of roads that could be damaged by heavy trucks. Since the major access route, Cypress Road, would be partially reconstructed by the project, this type of project condition may not be necessary. (3.2-13; NS) 3.3 AIR QUALITY a. Construction air quality impacts would be due to The dust control measures proposed as part of the dust generated by equipment and vehicles. Fugitive project plans should be made conditions of the project dust is emitted both during construction activity and approval. (3.3-1) as a result of wind erosion over exposed earth surfaces. Clearing and grading activities comprise the In addition to the dust control measure proposed by major source of construction dust emissions, but the project,all construction vehicles should be limited traffic and general disturbance of the soil also to 15 miles per hour while on the project site. The !. generate significant dust emissions.(PS). 15 mph limit should be posted on the site at all times during construction. (3.3-2; NS) b. The daily increase in regional emissions(Reactive Comply with the County's Transportation Demand Organic Gases and Oxides of Nitrogen (two Management Program Ordinances 92-31 by preparing precursors of ozone), associated with. the project and providing TDM information to prospective home would exceed the criterion (150 lbs/day). Therefore buyers. The TDM information should contain the project is considered to have a significant effect materials describing transit,ride sharing and van pool on regional emissions.(S) services. (3.3-3) 2-10 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED ' (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) The project should provide for transit stops along Cypress Road within the project site, along Cypress Lakes Drive, Sandmound Boulevard and Country Club Drive. (3.3-4) The proposed project design includes pedestrian/bicycle paths linking recreational and residential uses within the site (see Section 3.9). In addition to these facilities, bicycle parking areas should be provided at all recreational facilities within the project site (Golf Course Clubhouse, Beach Club and Public Ballpark). (3.3-5) While the mitigation measures discussed above would reduce regional emissions,the proposed project would still result in an unavoidable impact on regional emissions. (ROG and NOx) (S) 3.4 VEGETATION AND WILDLIFE a. The project would result in the removal of Wetland Habitat Mitigation Monitoring Plan which is approximately 0.95 acres of the 9.18 acres of designed to replace impacted wetlands by enlarging wetlands/waters of the U.S.on the project site for the and enhancing the existing wetlands on-site. The goal development of project roads, single-family homes, of the mitigation plan is to create an additional 2.28 golf course improvements and project levees. This acres of seasonal wetlands by enlarging and includes impacts to the primary drainage ditch("main enhancing the existing wetlands on-site. Buffer areas drain")by culverting the ditch under roads and filling around wetland areas would also be provided. (3.4-1) for construction of the project levee system.Filling of wetlands/waters of the U.S.on the project site would Channel Enhancement Plan which would enhance and require a permit from the U.S. Army Corps of widen the existing primary drainage ditch to a channel Engineers. of approximately 8 acres in size. A new north/south channel would also be created to connect to the proposed lake. The channels would be sprigged with willows and cottonwood cuttings to provide riparian habitat. (3.4-2) The proposed project includes widening of the primary drainage channel ("main drain") and the creation of additional channels on the project site to improve wildlife habitat and the visual quality of the project. The project applicant should prepare a 2-11 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) detailed Channel Enhancement Plan based on the draft Channel Enhancement Plan provided by the applicant. The Plan should be submitted to Contra Costa County,the California Department of Fish and Game and the U.S.Army Corps of Engineers for review and approval prior to approval of the project's final subdivision maps. (3.4-3) To minimize impacts to wildlife movement along this drainage channel, road crossings should utilize clear span bridges if feasible. If culverts are to be used they should be as large as possible to minimize impacts to wildlife movement. The design of all bridges and/or culverts to be placed along the primary drainage channel("main drain")shall be submitted for r review and approval to Contra Costa County Department of Public Works, Reclamation District 799, California Department of Fish and Game and �. U.S. Army Corps of Engineers prior to filing a final subdivision map. (3.44) The project plans include a draft Habitat Mitigation and Monitoring Plan which proposes to replace wetlands on-site,in a ratio of 3 acres for every 1 acre impacted (0.75 acres impacted to be replaced with 2.28 acres of new wetland) by enlarging and enhancing the existing wetlands on the project site and providing buffer areas around wetlands. The ' Habitat Mitigation and Monitoring Plan should be reviewed and approved by the County, California Department of Fish and Game and U.S. Army Corps of Engineers prior to filing a final subdivision map. (3.4-5) Wetlands and waterways impacted by the proposed t project are considered waters of the United States and therefore come under the jurisdiction of Section 404 of the Clean Water Act. Filling in waters of the United States requires a permit from the Department of the Army, U.S. Army Corps of Engineers. The project applicant is required to obtain a permit from 2_12 r TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) the U.S. Army Corps of Engineers before filling of any wetlands or waters on the project site. The type of permit required will be defined by the U.S Army Corps of Engineers upon submittal of a permit application by the project applicant.In addition to the U.S. Army Corps of Engineers permit,the California Department of Fish and Game may need to be notified regarding project activities in the vicinity of the main drain pursuant to Fish and Game Code Section 1600 et. seq. (3.4-6) The project should pay the County Protection Fee,as required by the County General Plan, for acquiring development rights on wetland areas off-site. The Protection Fee should be paid upon the issuance of building permits for the project. (3.4-7; NS) ,. 3.5 VISUAL QUALITY a. The project would result in changing the existing The following measures are proposed by the Project visual character of the project site to one of a Applicant to address visual impacts: suburban residential community with various recreational uses. This change would substantially Landscape criteria for the proposed golf course,parks, alter the existing visual condition. This would be common areas, project levees and the channels. considered an unavoidable impact of the project. (S) Landscaping would consist primarily of low grasses and wildflowers with some introduced shrubs and trees. (3.5-1) Landscape guidelines for the proposed levee system. These guidelines are designed to be consistent with the landscape guidelines of the State Reclamation Board. A list of suitable plant species is provided as part of the guidelines. (3.5-2) A landscape strip would be provided outside the project levee to provide screening of the levee along Bethel Island Road and Sandmound Boulevard. The landscape strip would be a minimum of 10 feet wide and be located sufficiently outside the levee cross- section to not hinder maintenance of the levee. The 2-13 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MI'T'IGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) landscape strip should be planted with trees and shrubs to provide maximum screening. Maintenance of the landscape strip would be carried out by the homeowners'association or special district but not the public agency responsible for maintenance of the project levee. (3.5-3) Residential units will be limited to two stories not to exceed 30 feet. (3.5-4) Minimum setbacks along arterial roadways will be 200 feet, and 100 feet from the center line of the roadway to the exterior wall of any living space along collectors (Cypress Road Extension). (3.5-5) Sideyard setbacks will vary taking into account: I) structures should not block solar access for heating and cooling;2)space between buildings shall increase in relation to their height; and 3) periodic view corridors to water areas should be provided. (3.5-6) Mitigation measures proposed by the project, or included as mitigation measures, would improve the visual character of the project site but would not mitigate the change in visual character to a less-than- significant degree. (S) b. Views of the project site from Bethel Island The levee landscape guidelines should be finalized , Boulevard,Sandmound Road and other vantage points once the public agency to be responsible for around the project perimeter would be partially maintaining the levees is determined. The levee blocked by a landscaped flood control levee which landscape guidelines should then be submitted to the would surround the project. The degree of impact public agency responsible for maintenance of the would be higher for residences closest to the levee. levees for review and approval prior to the installation of any landscaping on the levees. (3.5-7) A landscape maintenance district, or other funding source consisting of the property owners within the project site, shall be established for the proposed project to pay for long-term maintenance of public �. recreation areas within the project site. The project applicant shall submit a proposal for the landscape 2-14 t ■ TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) maintenance district to the County for approval prior to approval of the project's final subdivision map. (3.5-8; NS) 3.6 NOISE a. Existing houses along Cypress Road just west of Noise mitigation installed (soundwalls, architectural the project entrance would be exposed to a significant treatments), along Cypress Road for the project noise impact due to increased traffic by the year entrance to Sellers Road should be designed to 2000. (PS) achieve the County's 60 dB goal for residential uses. The proposed project should be required to pay 40% of the total cost of noise mitigation for houses along Cypress. This is based on the calculation that the project will contribute 4 dB to the ultimate 70 dB noise level along Cypress Road which is 10 dB over the County's 50 dB goal. The remaining 60% of the cost should be paid by the County (40%) and future development (20%). The project's prorata share of noise mitigation should be paid at the time of filing each phased final map. (3.6-1; NS) b. Existing residences adjacent to the site, In order to reduce construction period noise impacts particularly along Sandmound Boulevard, would be the following mitigation should be implemented: exposed to a short-term impact from construction noise. (PS) a. All general construction activity should be limited to the hours of 7:30 a.m. to 7:00 p.m. on weekdays only. b. Operations of any machine or device which generates a noise level greater than 95 dB at 50 feet should be prohibited wherever feasible. C. Route heavy construction traffic along existing Cypress Road and the proposed Cypress road to minimize the impact on existing residences. No construction traffic should be routed along Bethel Island Road or Sandmound Boulevard. 2-15 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) d. Prohibit construction trucks from parking along existing Cypress Road west of the project entrance. e. Locate noisy stationary equipment, such as r compressors or pumping stations away from existing residences to reduce their noise impact. (3.2-6: NS) c. Proposed housing along the extension of Cypress In order to avoid adverse noise levels at homes to be Road within the project would be exposed to a located along the extension of Cypress Road through existing and future DNL of 65 dB. This is 5 dB over the project, the project has been designed to provide the County goal for normally acceptable outdoor noise a 100 foot set-back along Cypress Road. The 100 levels but is within conditionally acceptable noise foot set-back would be from the center line of the levels. (PS) roadway to the nearest exterior wall of each residence located along Cypress Road. The 100 foot set-back would reduce the noise level at these residences to a DNL of 60 dB which is consistent with the County's noise goals for residential uses. No additional mitigation is necessary or proposed. (3.6-3; NS) 3.7 HYDROLOGY AND DRAINAGE a. The project would increase the area of The following mitigation measures are proposed as impermeable surfaces and increase storm water part of the project: �. runoff. The proposed channel lake system and storm drainage network would reduce the project's drainage On-site storm drainage facilities (lake, channels and impacts. On-site storm drainage that previously was golf course detention facilities)shall be constructed to collected in ditches and flowed off-site to RD-799 both protect property and to provide for public safety pumps, would, for the most part,be collected on site by accommodating the 100 year storm event. (3.7-1). and terminate in the proposed channel/lake system. During storm periods when excess water accumulates Dewatering structures(discussed in the Water Quality on the site, waters from the lake would then be Section) shall be constructed at those points where pumped to ultimate disposal in Sand Mound Slough underground storm drainage pipes enter the by a pump station that would be constructed as part channel/lake system in order to facilitate the periodic of the development. (NS) flushing and cleaning of the underground pipes.(3.7-2) Drainage ditches shall be constructed along the exterior toe of the proposed levee system to catch that runoff from the exterior slope of the levees. The 2-16 TABLE 2-1 (continued) SUMMARY OF PROTECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) drainage ditches shall discharge into existing drainage ditches along the perimeter of the project. (3.7-3) Maintenance of on-site storm drainage improvements within the public right-of-way, or in suitable easements, shall be performed by the County of Contra Costa. Storm water pump station maintenance shall be performed by the public entity selected to be responsible for the operation and maintenance of the perimeter levee. (3.7-4;NS) b. The 685.9 acre project site would be removed The following mitigation measures are proposed to from the FEMA flood hazard zone by construction of ensure proper construction, landscaping and a perimeter levee. Material for construction of the maintenance of the internal levee system. levee would be obtained from the excavation of the interior channels-lake system. The levee would be The design of the project levee shall be in accordance constructed to standards adopted by FEMA for an with the standards and requirements of the Federal Urban Standard Levee. (B) Emergency Management Agency for an Urban Standard Levee. Provisions shall be designed into the project levee to allow for a future increase in height of four feet to allow for the "greenhouse effect." During the design of the project levee, the crest elevation shall be increased by an amount equivalent to projected long term settlement. (3.7-5) The side slopes of the project levee shall be planted and irrigated to reduce erosion, and to provide dust control,in accordance with the limitations imposed by FEMA. (3.7-6) Adequate easements shall be granted to the maintaining authority in order to provide for maintenance and upgrading of the levee, and to prohibit encroachments onto the levee. (3.7-7) To minimize the risk of liquefaction beneath the perimeter levees, the loose clean and silty sand of depths of 10 to 15 feet shalt be reworked and densified. Deep dynamic compaction and/or over excavation and compaction of soils shalt be utilized to densify the soils. (3.7-8) 2-17 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) The levee landscape guidelines should be finalized once the public agency responsible for maintaining the levees is determined. The levee landscape guidelines should then be submitted to the public agency responsible for maintenance of the levees for review and approval prior to installation of any landscaping on the levees (same as mitigation measure 3.5-7) (3.7-9) A detailed emergency evacuation plan based on the project's proposed emergency evacuation plan shall be prepared in cooperation with RD-799 and the governmental agency that ultimately accepts the internal levee system prior to approval of the project's final subdivision map. The evacuation plan shall include at a minimum the following measures: • Criteria for determining when a emergency exists • Methods for notifying and evacuating area residents • Identification of agencies and individuals responsible for emergency response and public evacuation • Plans for returning evacuees to their homes after an emergency has passed. (3.7-10;NS) c. Existing soils within the project site would be The proposed groundwater monitoring plan shall be removed (for the lake/channels) to construct the made a condition of project approval. A final proposed levee system. The proposed.project would groundwater monitoring plan shall be submitted for have a short-term impact on groundwater as a result review and approval by the County prior to filing a of dewatering of near-surface groundwater for final subdivision map. (3.7-11; NS) excavation for the internal levees, lake, channels and installation of utilities. The localized dewatering activities would not affect adjacent properties because dewatering would occur far enough from existing residences and draw down would only occur on the project site .immediately under or adjacent to the dewatering area. In addition,the project plans include , a groundwater monitoring plan. (PS) 2-18 r TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) d. The project would not have an impact on the The project site shall continue to be a part of RD-799 condition of the existing RD-799 levee system. and shall be prohibited from seceding from this However, the project site does provide funding for district, even if removed from the flood hazard zone continued maintenance of the RD-799 levee system by the proposed internal levee system,to provide the and RD-799 may ultimately be responsible for district with a continued long-term source of funding maintenance of the proposed levee system. (PS) for maintenance of the existing RD-799 levee system. (3.7-12; NS) e. Increased surface runoff from the new impervious A final maintenance plan for the Golf Course shall be surfaces and the golf course may have impacts on the submitted for review and approval by the County, water quality of the channels-lake and ultimately the prior to filing a final subdivision map. The final Delta. Urban runoff can contain substantial quantities maintenance plan shall build on the maintenance of pollutants slich as organic pesticides,heavy metals, criteria established in the project plans and identify nutrients, petroleum products, and suspended solids. standard maintenance and management practices to be To address this potential impact, the project plans carried out on the Golf Course. Specific maintenance include a water quality management plan and procedures shall be identified regarding the use of maintenance criteria for the golf course. However, pesticides,herbicides,and fertilizers. An emphasis of proper implementation is necessary to ensure adequate the maintenance plan should be to reduce potential water quality. (PS) leaching into local groundwater resources. The maintenance and management plan shall also outline specific irrigation practices designed to reduce water consumption. (3.7-13) An informational packet shall be distributed to all project residents to educate them on the use and disposal of undesirable materials such as motor oil, paints, garden pesticides and other household products. The informational packet should be distributed to project residents upon purchase of each house. (3.7-14) A street sweeping program shall be provided to reduce urban pollutant run off into the proposed lake and channels. The street sweeping may be provided by the County through its existing street sweeping program. If this is not feasible,alternative measures could include funding of the street sweeping program by the homeowner's association. (3.7-15) A final channel-lake operation and maintenance plan shall be submitted for review and approval prior to 2-19 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) filing a final subdivision map. The plan shall be based .on the applicant's proposed lake-channel management plans utilizing plants, flushing,aeration and other techniques to maintain water quality without chemicals. (3.7-16) I The project shall comply with all the requirements of the County's NPDES permit requirements. The project applicant shall provide the County with the appropriate documentation regarding compliance with NPDES requirements prior to the issuance of grading permits for the project. (3.7-17; NS) 3.8 GEOLOGY, SEISMICITY AND SOILS a. The project would expose new structures to the The project plans include the following mitigation potential impacts of liquefaction. Due to the measures: "Generally High" liquefaction potential on the project site and County policies, this impact would be Excavate,rework and densify the loose clean and silty considered potentially significant. (PS) sands under the levee to a depth of 10 to 15 feet. Deep Dynamic Compaction (DDC) techniques could also be used. These techniques could involve dropping a heavy weight repeatedly at a given location. (3.8-1) If Deep Dynamic Compaction is used,vibration from this construction technique would be monitored along the property line closest to adjacent residences. However,vibration from DDC would not be expected to exceed safe limits beyond 150 feet from the excavation site and therefore would not affect any adjacent residences. (3.8-2) The following mitigation measures are proposed in addition to those measures proposed as part of the project: The Kleinfelder report analyzed alternative approaches for mitigating liquefaction impacts. The project should be required to adhere to these approaches. 2-20 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) The specific approach will depend on site-specific conditions and analysis. However, the project applicant should follow the reviewed and approved recommendation of the Kleinfelder report. A report documenting the methods used in the field to reduce liquefaction potential should be submitted to the Public Works Department and the public agency responsible for maintenance of the levee system. (3.8-5) Building plans for each structure to be constructed on the project site shall include an evaluation .and recommendations to ensure satisfactory performance in the event of an earthquake and liquefaction on the project site. The building plans shall be reviewed and approved by Contra Costa County prior to the issuance of building permits. (3.8-8; NS) �- b. Construction of the project would result in grading The project plans include the following mitigation over much of the site for construction of the proposed measure: homes, golf course, lakes and other facilities. These activities would expose soils to wind and water Existing vegetated areas should be left erosion. Because the site is located in an area of undisturbed until construction of site strong winds, wind erosion could result in a improvements is actually ready to significant loss of soil without mitigation.(PS) commence. • All disturbed areas should be protected from both wind and water erosion upon the completion of grading activities. • Runoff should be directed away from all areas disturbed by construction, if practical. • Temporary check dams, sediment ponds, or siltation basins should be used to trap eroded soils, and prevent their discharge into storm drain pipes. 2-21 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS �. (Mitigation Number In Text; Significance Of Impact After Mitigation) • To the extent possible, major site development work involving earth moving , and excavations should be scheduled for the dry season. • Areas used for stockpiling and staging construction equipment and materials should be located so that unchecked runoff from these areas does not enter the storm drain system. (3.8-4) The following mitigation measure is proposed in addition to the measures proposed as part of the project: Post at the construction site the name and phone number of a designated dust control coordinator who can respond to complaints by suspending dust- producing activities or providing additional personnel or equipment for dust control. In addition contractors shall implement, at a minimum, the following measures: 1) Schedule earthmoving activities,as much as possible, during the early spring months when soil moisture is high. 2) Suspend earthmoving or other dust-producing activities during periods of extreme winds. 3) Provide equipment and staffing for watering of all exposed or disturbed soil surfaces at least twice daily, including weekends and holidays. An appropriate dust palliative or suppressant, added to water before application, should be utilized. 4) Water or cover stockpiles of debris, soil, sand or other materials that can be blown by the wind. 5) Sweep adjacent streets of all mud and debris, since this material can be pulverized and later resuspended by vehicle traffic. 2-22 - r TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation)' 6) Where possible, limit the speed of all construction vehicles to 15 miles per hour while on site. 7) Seed, cover or chemically treat finished grades as soon as practical after completion of activities. (3.8-7; NS) c. The potential for subsidence from dewatering The following measure is proposed as part of the would be short-term (only during dewatering project plans: activities)and would only occur in the immediate area of dewatering activities. Dewatering activities are Groundwater monitoring plans to provide early M expected to occur during the excavation for the lake detection of changes in the groundwater level and to and channels, construction of the levee and allow adjustments in the construction techniques if installation of underground utilities. Dewatering necessary. Monitoring wells and settlement plates activities would effect the top 15 to 20 feet, which would be placed on the project site and surrounding would not impact most domestic wells which are properties to control the groundwater level. (3.8-3) generally below the depth of the dewatering activities (Bohely, 1992). The localized dewatering activities The following mitigation measure is proposed in would not cause subsidence on adjacent properties addition to those measures proposed by the project: because draw down would only occur on the project site immediately under or adjacent to the dewatering The ground settlement monitoring plan should be area. (PS) finalized and submitted to the County for review and approval prior to beginning any construction or dewatering activities. The plan shall identify the location of all monitoring wells,and provide specifics on well completion and the method and frequency of monitoring. Similarly, the plan shall identify settlement plates as well as contingency plans to control subsidence or mitigate subsidence related damage. (3.8-6; NS) 3.9 PUBLIC SERVICES a. The project would increase fire protection service The project proposes to dedicate a site and construct demands on the fire districts by increasing the number a new fire station on the project site in lieu of fire of structures and population within the project area. protection fees as determined by the County. The site To reduce the project's impacts on fire services, the and station should meet all applicable requirements of project would include construction of a fire station the appropriate Fire District (Oakley FPD or Bethel near the project entrance at Cypress Road. This Island FPD). The fire station should be operational station would satisfy the County's standard that fire prior to the first homes on the site being occupied. If stations be located within one and one-half miles of necessary a special district fee may be augmented to 2-23- TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) development,and satisfactory to the Bethel Island and provide adequate funding to fully staff the new Oakley Fire Districts for maintaining the five minute station. (3.9-1) / 1.5 mile response standard. The proposed project, therefore, is not expected to have an adverse impacts If the project is required to pay fees, the Fire District on fire protection facilities.(NS) fees shall be based on the fees in effect at the time of the issuing of building permits. (3.9-2) All building plans shall meet the applicable Uniform Building and Fire codes. Fire protection agencies shall be afforded the opportunity to review and comment on plans prior to the issuance of building permits for the projects. (3.9-3) b. The project would result in the addition of The proposed project should pay a fair-share fee equal approximately 3,247 persons population within the to the cost of providing 465 square feet of new County sheriff's service area. This would result in Sheriff Department facilities, based on the County the need for new officer positions and equipment.(PS) standard of 155 square feet per 1,000 residents. The fee should be calculated and paid at the time of issuance of building permits for the project. (3.9-4; NS) c. The project would generate approximately 665 School Impact fees shall be based on the fees in �. new elementary and middle school enrollments and effect at the time of issuing building permits. (3.9-5) approximately 253 new high school enrollments. Based on the project's student generation and the School impact fees are projected to be insufficient to local school district's school facility requirements,the cover the project's share of facilities required to serve proposed project would require the construction of new students in the area. If no state or local funding approximately one new elementary school, 30% of a is available,the applicant should work with the school new middle schools,and 20%of a new High Schools. districts to determine additional school fees to be paid The project includes a possible school site of as building permits are issued. (3.9-6) approximately 7.4 acres. This site is proposed to mitigate the project's impacts on the local school The school site should be enlarged from 7.4 acres to district. The OUESD has indicated that a 10 acre 10 acres to meet the OEUSD requirements. (3.9-7) school site would be desired.(PS) If the proposed on-site school site is determined by the OUESD to be unacceptable, the applicant shall pay an in-lieu fee to the OUESD for the purchase of an appropriate school site. (3.9-8; NS) 2-24 r TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED ' (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) d. The project would include 170 acre semi-private The following mitigation measures are proposed to golf course,60 acres of channels and lake,a 1.5 acre ensure proper maintenance of park facilities and beach club, approximately 33 acres of parks, and a compliance with County policy: day care facility. The project is consistent with the park land/recreation requirements of the County. (B) The project proposes to construct and dedicate the large community park to the County which would then be responsible for continued maintenance of the park. If this is unacceptable to the County, funding for maintenance of the community park should be provided through a special district. (3.9-9) The community park should be designed so that active recreational use areas are located outside the power line easement. Active uses to be located outside the easement include: baseball diamonds, soccer fields and play ground areas. Uses permitted within the easement should be passive recreation and landscape areas. (3.9-10) The project applicant shall prepare a child care needs assessment based upon the projected demographics and density of the proposed project. The needs assessment shall be submitted to the Community Development Plan prior to approval of the final phase map for_the portion of the project which includes the ! day care site. (3.9-11; NS) e. The Contra Costa Mosquito Abatement District CCMAD should be provided the final design plans for (CCMAD) notes that the environmental conditions in wetland mitigation areas and golf course maintenance the area indicate that the project would cause an and irrigation for review and comment prior to their increase in the level of service required from approval. (3.9-12; NS) CCMAD. Golf courses, parks and water detention basins proposed as part of the project can lead to mosquito problems year round. (PS) 3.10 UTILITIES a. Water requirements for the project would amount Implement a groundwater management plan to address to approximately 1.7 million gallons per day (mgd). water requirements for irrigating the golf course and This can be broken down into 884,150 mgd for parks and to monitor changes in the groundwater domestic use and 805,200 mgd for landscaping.The table. The groundwater management plan should also 2-25 TABLE 2-1 (continued) U SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) project is proposing to utilize existing groundwater address the management of pesticides and measures resources for irrigation of the golf course, parks, to be taken to reduce potential impacts on wetlands, and certain levee areas. The Oakley Water groundwater resources. In addition, the plan should District appears to be the logical provider of domestic identify what areas,and in what sequence,water will water service to the proposed project and has be discontinued to portions of the golf course and provided a "will serve" letter to the project applicant parks in the event of water cutbacks because of confirming that water capacity is available to serve drought or substantial lowering of the water table. this project through its buildout. (PS) The plan should be approved by the County prior to filing a final subdivision map. (3.10-1) Design into the golf course the use of grasses that are drought tolerant to limit the amount of water necessary for irrigation. (3.10-2) Require all structures to confirm to the California Health and Safety Code Section 1792.3 and the Public Resources Code Section 25402 with regard to maximum flow rates through plumbing fixtures. (3.10-3) Provide homeowners with alternative landscaping opportunities such as xeriscape landscaping for builder installed front yards. (3.104) Design water distribution systems in accordance with American Water Works Association standards. (3.10- 5) Install cathodic protection where corrosive environments are found, and use metallic water line products. (3.10-6) Install cathodic protection where corrosive environments are found and metallic water line products must be used. (3.10-7; NS) b. The project proposes to obtain its domestic water The project should be required to construct,or pay a supply from the existing OWD mains located at the fee equal to, the necessary off-site water system intersection of Highway 4 and Cypress Road in improvements to serve the proposed project. The size Oakley. From that point,the project would construct and design of these facilities should meet all two separate 12" pipelines, that are periodically applicable standards and requirements of the Oakley. 2-26 r L TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MkTIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) interconnected, to the project site. The 12" pipelines Water District and local Fire District Standards. The would have sufficient capacity to serve the proposed project should be reimbursed on a proration basis for project as well assome limited additional the cost of constructing facilities which have the development within the Bethel Island area. (NS) capacity to serve future development in the Planning Area served by the facilities. The necessary off-site water facilities should be completed and operational prior to the first homes being occupied on the site. (3.10-8; NS) c. The project would result in a significant increase The project applicant would be required to construct in wastewater generated from the project site. Based all necessary sewage collection facilities on-site to on wastewater generation factors provided by the serve the project. These facilities should be built to Oakley Sanitary District, the proposed project would district standards and appropriate easements for generate approximately 360,000 gallons/day (or 0.36 district maintenance provided. The sewage collection �. mgd) based on 270 gallons/unit day x 1,330 units. facilities should be installed prior to the first homes The most logical provider of sewer service for the being occupied. (3.10-9) project is the Ironhouse Sanitary District because 75% of the proposed project site is located within their A hydraulic analysis of the force main should be existing service boundaries. The project applicant has conducted to determine the capacity of the existing requested that the remainder of the project site be force main and any improvements that may be annexed to the Ironhouse Sanitary District. The necessary to accommodate the proposed project. This Ironhouse Sanitary District appears to have adequate analysis should be conducted prior to approval of the capacity to serve the project and has provided a "will project's final subdivision map. The project shall pay serve" letter to the project applicant. However, there its fair share of any improvements necessary to the may be several off-site improvements necessary to force main to serve the project. The fair-share fee f serve the project. (PS) shall be paid upon approval of the first phased map. (3.10-10) The project should be required to pay the full costs of any increase in pumping capacity or new pump station(s) necessary to serve the project. The need and cost for these improvements shall be determined by the Ironhouse Sanitary District prior to approval of the final map. (3.10-11) A reimbursement agreement shall be entered into between the project applicant and the Ironhouse Sanitary District whereby the project applicant would be reimbursed for the portion of the cost of new facilities which have the capacity to serve areas in addition to the project. The reimbursement would be 2-27 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) paid out of fees paid by future developments. (3.10- 12; NS) d. Electric service would be supplied to new The project shall include the undergrounding of all ' development by PG&E. The existing transmission new electrical service lines necessary to serve the lines and substation appear to have adequate capacity project site. Electrical lines should be placed in to provide service to the project.(NS) relatively water tight conduits according to PG & E ' standards. This should be completed prior to the first houses being occupied. (3.10-13) The need to upgrade off-site electrical lines shall be determined by PG&E prior to approval of the final map. 'If off-site reinforcement is necessary, the project applicant should be required to pay the project's fair-share, if any, of the reinforcement. (3.10-14; NS) e. The project would require the replacement of the Place distribution lines underground. (3.10-15) switch on Bethel Island and the extension of new telephone cables to the project site.According to PUC Install telephone cables in relatively water-tight regulations, costs of line and equipment installation conduits and vaults. (3.10-16; NS) �+ would be borne by the developer and Pacific Bell. According to County policy, distribution lines would need to be placed underground in relatively watertight conduits and vaults, thereby avoiding visual impacts and prolonging the life of the equipment and cables.(NS) L The project includes street lighting and additional Project street lights should utilize down focused lights lighting associated with individual residential units and other features to reduce glare. The design of and recreational uses. The street lighting would be street lights should be submitted for review and installed in accordance with Contra Costa County approval to the County Public Works Department for Code(Title 9)requirements and maintained by Contra review and approval prior to approval of the final Costa County. Street lights produce "glow" which . map. (3.10-17; NS) could impact adjacent residents. (PS) 2-28 f TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED �. (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) 3.11 HUMAN HEALTH a. Residents of the project could be exposed to Each residence on the project site should include in agricultural chemicals applied aerially on nearby its CC&Rs a clause consistent with disclosure �. agricultural lands. However, the use of agricultural currently required by the County stating that the chemicals is strictly regulated by County and State incoming' property owner is aware of adjacent regulations. Chemicals applied aerially on nearby agricultural uses and the potential hazards related to properties could drift onto the project site and cause this land use. (3.11-1; NS) adverse health effects and nuisance odors for project residents. The level of exposure for project residents would vary greatly depending on the amount of chemicals used and proximity to the application.(PS) b. The project would involve the construction of The Contra Costa Mosquito Abatement District lakes, a golf course and other water related facilities (CCMAD) should be consulted regarding mosquito including wetland mitigation sites,drainage facilities. abatement features during the final design of any These facilities may provide breeding habitat for wetland mitigation sites to be created on the project mosquitos if not properly maintained.(PS) site (3.11-2) If reclaimed water is used for recreation areas, CCMAD should be consulted regarding the design and testing of alternative methods and disbursement sources.(3.11-3; NS) c. The project site is located in close proximity to Each residence within the project site should include large electrical transmission lines and natural gas drill in the CC&Rs a clause stating that the incoming easements (no active gas sites). Although some of property owner is aware of the specific human health these risks are speculative,as a result of the project's issues related to living near electrical transmission location,project residents could be exposed to certain lines and drill sites. (3.11-4; NS) health risks.(PS) 3.12 CULTURAL RESOURCES a. Because the project site is known historically to Due to the existence of subsurface cultural materials contain cultural resources,including the possibility of along the western perimeter of the CA-CCo-134 site human burials,the proposed project may result in the area and the recommendations relative to site CA- disruption of cultural resources as a result of the CCo-139 (below), it is recommended that significant grading and excavation necessary to construct various ground disturbance be avoided in an area of components of the project.(PS) approximately 11 acres (700 x 700 feet [213 x 213 meters])(see Appendix H). The proposed uses in this area (internal levee, natural gas drilling site, fire 2-29 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) station,community park)are not expected to result in significant ground disturbance. However, all construction activity in this area should be closely monitored to preserve known resources and to determine the presence of any previously unknown subsurface resources in the CA-CCo-134 area. Should sterile soil (e.g., topsoil) be placed over the site for landscaping purposes,it is recommended that rubber-tired construction vehicles be used throughout the site area and that excavation for landscaping or irrigation be allowed in fill material only. Should it be necessary to excavate through native soils; an archaeologist should be present to monitor soil removal for the presence of cultural materials. (3.12- 1) Significant ground disturbance should be avoided in the area surrounding site CA-CCo-139, from the 0- foot(sea level)contour to the mound apex at 6.5 feet above sea level(see Appendix H). The proposed uses in this area (community park, extension of Cypress Road are not expected to result in significant ground disturbance. However, all construction activities should be closely monitored to preserve known resources present in this area. It is understood that two private parcels of land on the mound are not included in the project proposal. These recommendations do not applyto those parcels unless they are incorporated into the project proposal at some future time. Should any subsurface disturbance occur on the mound through the removal of structures or foundations, an archaeological monitor should be present to observe soils for the presence of cultural materials. Should sterile soil(e.g.,topsoil)be placed over the site for landscaping purposes, it is recommended that rubber-tired construction vehicles be used throughout the site area and that excavation for landscaping or irrigation be allowed in fill material only. Should it be necessary to excavate through native soils, an archaeologist should be present to monitor soil removal for the presence of 2-30 TABLE 2.1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) cultural materials. (3.12-2) Construction at the fire station, which would be within the area of archaeological sensitivity for site ' CA-CCo-139,should be closely monitored and work stopped immediately if cultural materials are encountered. If it is determined that construction is not feasible, the project applicant shall be required to find an alternate site outside the archaeologically sensitive area. (3.12-3) . Lot No.10 in Neighborhood 1 should be removed or redrawn in a manner that avoids the archaeologically sensitive area associated with CA-CCo-139. (3.12.4) Lot No.I I in Neighborhood 1 should be removed or redrawn in order to avoid the archaeologically sensitive area associated with CA-CCo-139. (3.12-5) The area including and immediately surrounding site CA-CCo-647 should be avoided to preclude impacts to this important resource(see Appendix M. Should sterile soil (e.g., topsoil) be placed over the site for landscaping purposes,it is recommended that rubber- tired construction vehicles be used throughout the site 1j area and that excavation for landscaping or irrigation be allowed in fill material only. Should it be necessary to excavate through native soils, an archaeologist should be present to monitor soil removal for the presence of cultural materials. (3.12-6) rThe rear lot lines of lots No.29 and 30 in Neighborhood 7 should be redrawn in a manner that avoids the archaeologically sensitive area associated with CA-CCo-647. (3.12-7) In the event that avoidance of the preceding cultural resource sites is not feasible, it will be necessary to develop a data recovery or"excavation plan"pursuant 2-31 ■ TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MI'T'IGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) to the requirements of CEQA Appendix IC, Part V and subject to the limitations defined in Part VI. (3.12-8) An archaeological monitor should be present when grading, excavation, trenching and other soil disrupting activities are carried out in any of the mapped archaeologically sensitive areas as defined in E Appendix H. These activities/areas include, for example, the Cypress Road extension; levee construction/ excavation/ compaction; possibly, demolition of existing homes; fire station construction; and the parking lot for the playing fields. (3.12-9) An archaeological monitor should be on-call when grading, excavation, trenching and other soil disrupting activities are carried out on the project site. In the event that a prehistoric site,burial,or historic resource is encountered during construction of the project, the project engineer would be obligated to _ temporarily stop or relocate construction activities and notify the archaeological monitor immediately. In the event a significant prehistoric or historic resource is identified,no further construction should be permitted in that location until a mitigation plan can be formulated and implemented. (3.12-10) In the event human remains are discovered during construction, excavations should be halted at that location. Any finds of human remains must be reported to the Contra Costa County Coroner's Office. In the event that the find is determined to be prehistoric, the Native American Heritage Commission must be notified within 24 hours to alert them of the find and to permit the designation of a Native American representative. Consultation between the archaeological consultants in charge of monitoring, Contra Costa County, and the Native American representative would then determine the course of action to be taken with the burial in 2-32 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) question. Ideally, if removal is undertaken, time should be allowed for study of the remains and any associated grave goods prior to their return to the Native American Community for reburial at a location of their selection. (3.12-11) A report of findings and analyses of all archaeological data recovered during testing/excavation,monitoring and any mitigation procedures undertaken should be prepared by a qualified archaeologist. (3.12-12) Sections 5097.98 and 5097.99 of the Public Resources Code also call for "protection to Native American ' human burials and skeletal remains from vandalism and inadvertent destruction". To achieve this goal, it is recommended that the construction personnel on the project be instructed as to the potential for discovery of cultural or human remains, and both the need for proper and timely reporting of such finds, and the consequences of failure thereof. (3.12-13) ' It is recommended that the Native American Heritage Commission (NAHC) in Sacramento be contacted regarding potential Native American concerns,values, and traditional use areas relative to the proposed project site and vicinity. There is a potential for disturbance of previously undiscovered Native American human remains during construction of the project. It would prove advantageous to have an established agreement with the NAHC and/or local Bay Miwok tribal representatives prior to the discovery of such remains,should any be discovered. A typical agreement would specify when,in the event of a discovery, Native American involvement would occur, and the treatment and ultimate disposition of ancestral remains. (3.12-14) ' The proposed intersection improvements at the project entrance and Bethel Island Road should be realigned to the north as much as possible to avoid impacting site CA-CCo-138. (3.12-15) 2-33 TABLE 2-1 (continued) SUMMARY OF PROJECT IMPACTS AND MITIGATION MEASURES IMPACT MITIGATION MEASURES PROPOSED (Significance) TO REDUCE SIGNIFICANT IMPACTS (Mitigation Number In Text; Significance Of Impact After Mitigation) The alignment of any future extension of Bethel Island Road south of Cypress Road should be as far east as feasible to avoid site CA-CCo-138;taking into consideration safety factors. This may result in the need to move the project levee along the project's westerly boundary up to 50 feet to the east. (3.12-16; NS) 3.13 ENERGY a. An average dwelling unit could be expected to Building plans for each house should include energy consume approximately 4,869 kilowatt hours conservation features such as passive solar heating, (kwh)/year of electricity. Total energy consumption additional insulation and other features so that Title of the proposed homes would be approximately 6.47 24 efficiency standards(1991)will be exceeded by at million kilowatt hours/year of electricity. The project least 10%. These features shall be reviewed and has proposed to incorporate design features in the approved by the County Building Department as part project homes so that energy consumption would be of the building permit review process. reduced. The goal of the project would be to exceed the energy efficiency standards of Title 24 by 10%. (B) 2-34 t 3. DESCRIPTION OF ENVIRONMENTAL SETTING,IMPACTS AND MITIGATION 3.1 LAND USE, PLANNING AND PUBLIC POLICY EXISTING SETTING Existingn i Land a d Uses h o the Prosect Site The project site is located in the East County area of Contra Costa County near the San Joaquin County line, approximately 2.7 miles east of the Town of Oakley (see Figure 1-2). The project site occupies about 685.9 acres at the junction of Cypress Road and Bethel Island Road in the Hotchkiss Tract. The site is bordered on the west by Bethel Island Road, on the north and east by Sandmound Boulevard, and on the south by the Prelli property. The site is located about one half mile north of Rock Slough (see Figure 1-2). Agriculture, primarily on the Dal Porto Ranch, is the predominant land use on the site. These lands have marginal agricultural productivity and are classified as "non-prime." Agricultural uses include cattle grazing and field 1 crops. Some rural residences and accessory structures are clustered near Cypress Road and Bethel Island Road; not all of these are included within the proposed project boundaries. Other rural residences and structures are clustered in the northern portion of the site near Sandmound Boulevard. The site contains about 9 acres of wetlands/waters of the United States. The southwestern.portion of the site contains three transmission line easements: a 200' Western Area Power Administration (WAPA) California-Oregon Transmission Project (COTP) easement; a 125'-wide U.S.A. tower and pole line easement; and a 350'-wide PG&E tower and pole line easement. The 125'-wide tower lines are planned to be removed. Along the site's western boundary, a Great Western Power Company pole line easement is located parallel to Bethel Island Road. Additional discussion regarding the transmission lines is contained in Section 3.12 of this EIR. LIn the 1930's Bank of America purchased Hotchkiss Tract. The bank sold off portions of the Hotchkiss Tract to individuals but retained surface and subsurface rights. The project applicant has been able to retain the surface rights to the project site. However, the bank has retained five areas for potential drilling sites which could be utilized for gas exploration and potential gas well development. These drilling sites total 10.5 acres in area and are located in various locations along the site's perimeter. While the project site is located within the Dutch Slough Gas Field, gas has never been discovered on the project site and there are no known gas resources on the project site. The drill sites on the project site do not contain wells or drills, they are currently vacant. A major drainage ditch crosses the site from Bethel Island Road to Sandmound Boulevard ("main drain"). This ditch is part of the RD-799 drainage system of the Hotchkiss Tract and conveys water to a pump station located near Sandmound Boulevard. 3-1 Existing Land Uses in Surrounding Area A This part of the County is predominantly rural and devoted to agricultural, recreational, ' and open space uses, with small amounts of commercial and industrial uses. The project area vicinity is generally characterized as low lying delta lands of the San Joaquin River which were reclaimed through the construction of levees and de-watering following the Swamp and Overflowed Lands Act of 1855. Most of these lands are at an elevation at or below mean sea' level. Hotchkiss Tract, in which the project site is located, is bordered on the west by Jersey Island Road, on the north by Dutch Slough and Bethel Island, on the south Rock Slough, and on the east by Sand Mound Slough. Of the 3,000 acres that comprise Hotchkiss Tract, a total of ' about 2,867 acres are in agricultural use; about 131 acres have been developed for residential use; and about 2 acres have been developed for commercial use. As described above, the lands in agricultural use on the project site have marginal productivity. Levees are constructed on 6.7 miles of its perimeter, along Little Dutch Slough, Dutch Slough, Sand Mound Slough and Rock Slough. The residences are primarily single-family homes; most are located along Sandmound Boulevard and have docking facilities on Sand Mound Slough. One multiple family housing development is located on Sandmound Boulevard. A small commercial area is located on Bethel Island Road near the Bethel Island Bridge. The transmission line easements described above for the project site continue diagonally across Hotchkiss Tract. Hotchkiss Tract is also a part of the Dutch Slough Gas Field and has about six operating natural gas wells. However, these wells are not located in the vicinity of the proposed project site. The Contra Costa Water District's Contra Costa Canal intake from the Central Valley Project is located near the western end of Rock Slough. Bethel Island lies immediately north of Hotchkiss Tract and Dutch Slough. The island consists of about 3,500 acres in agricultural,residential, commercial and recreational uses. About 3,215 acres are in agricultural use; about 271 acres have been developed for residential use; and about 14 acres have been developed for commercial use. A majority of the Bethel Island perimeter is developed with small-lot single family homes adjacent to the 11.5 miles of levees ' which surround the island. Most of these homes use the surrounding waterways for docking private boats. Small mannas with covered boat slips also operate commercially in these areas and are interspersed among the private docks. A commercial area with local and region-serving businesses lies immediately north of the bridge. Most of the land-in the interior of the island is fallow agricultural land, and is sparsely developed with several mobile home parks, single family homes, a small hotel and restaurant, boating facility and a golf course. Three natural gas wells, are located in the western portion of the island. Bethel Island may contain about 1,537 acres of wetlands. To the north of Bethel Island lies Franks Tract, a State Recreation Area which consists of two submerged islands whose broken levees remain above the water level. Jersey Island is directly west of Bethel Island and is used for agriculture. Holland Tract, also an agricultural 3-2 ' 1 ' area, lies immediately to the east of Hotchkiss Tract and Bethel Island. Other recreational uses in East County include the Antioch shoreline; a recreation facility at Big Break; Black Diamond Mines; the Contraloma area; plus various facilities operated by the East Bay Regional Park ' District. The nearest incorporated area is the City of Brentwood (pop. 6,800), about 15 miles ' southwest of Hotchkiss Tract. An application for the incorporation of the Town of Oakley was filed but has since been withdrawn. The.original application included Hotchkiss Tract and the project site. The project applicant filed a request that the project site not be included within the Oakley incorporation limits and the original application was revised to exclude Hotchkiss Tract (Jochim, 1992). Currently, the Oakley Incorporation Committee is sponsoring a fund raising drive to collect money needed to update and revise the application. (Brentwood News, October 9, 1992) The State Lands Commission has indicated in their letter in response to the Notice of Preparation that portions of Hotchkiss Tract, and the project site, may contain the last natural bed of Sand Mound Slough which could be considered sovereign property of the State of California ' or property encumbered by the Public Trust. Contra Costa County Community Development Department has requested that the State Lands Commission provide a map or other evidence indicating public ownership in the Hotchkiss Tract Area. To date, the State Lands Commission ' has not provided evidence of State ownership in the Hotchkiss Tract. The project site does not abut or contain any tidal (Delta waters) or submerged lands (natural waterways). According to the title company, pertinent State Lands Commission Maps do not indicate any State ownership ' interest. (Don Davidson, 1st American Title Company) Planned Land Uses In addition to the proposed Cypress Lakes project, three development applications are pending for residential/recreational projects in the Hotchkiss Tract: Lesher Landing (Lesher), ' South River (Bones), and North State Development Company (see Figure 3.1-1). Additional discussion of these projects and their potential cumulative impacts when considered in combination with the Cypress Lakes project, is contained in Section 5.2 of this EIR. As indicated in Figure 3.1-1, the project site is located in an area which is planned for residential development in conformance with the Contra Costa County General Plan. An EIR is anticipated for at least the Lesher project. ' In addition to other planned projects in the Bethel Island Area, there are three planned development projects which include golf course components in the Brentwood area: A.G. Spanos Brentwood Hills Country Club, Hancock Specific Plan, and the Blackhawk/Nunn Project. In addition, Cowell Ranch, a planned development community of at least 6,000 residential units with businesses and commercial uses for 5,000 acres, is proposed southwest of Brentwood. The City ' of Brentwood is also in the process of updating its General Plan. These planned projects exhibit the significant level of planned development in the East County area. Additional discussion of 3-3 1 a' etkeI Island l--_ Otl7 .••SiOtiGrlpWslping ••••%ROAD• i /:J , • Sia;--� <.. ;rV,-.•' '`�j�� T it g,. lh -�• beveloSite i 41 �r J T C H •SL0U H Q�_ G A S F I E L 1 Lecher Landing C " � a.a. . tilt _ � • +,�- .. _ _ or 00 'r`' 111 � f • . i 0 :S•tib.•'• a .`i ..�. ,=e— — c" *gip"''Z[C •t 81AM} Cypress Lakes a �.. • ntlmitl ,0 `:- 4 M _ ' ;ICI! i _— 00 oil 00 28 y,"y~•'fib' •� �� '� South 1 c,a,n• sa 9M•p C► :it .133 . uc ...............�.. [7..:,a.:........ live[ -'$joupli..... , �. Figure 3.1.1: CYPRESS LAKES & Other Planned Projects in the COUNTRY CLUB PROJECT . Bethel Island Planning Area Source: Contra Costa County Community Development 3-4 ' the potential impacts of these projects in combination with the Cypress Lakes project is contained in Section 5.2 of the EIR. 1 North of Cypress Road between Marsh Creek and Jersey Island Road, 1,539 acres have been designated for mixed-use development in an area referred to as the Cypress Corridor. The site is intended to function as a community center for Oakley. Land uses would include single ' family and multi-family residential (1,135 to 1,480 acres); commercial (15 to 20 acres); office (30 to 40 acres); commercial recreation (20 to 30 acres); parks and recreation (100 to 150 acres); and public and semi-public (25 to 35 acres). The Cypress Corridor development is also considered in the cumulative impacts analysis contained in Section 5.2 of this EIR. ' Existing Population and Housing Characteristics Proiect Site The site contains eight housing units consistent in character with the agricultural uses that dominate the site and its vicinity. Most residences in the vicinity are located on the east side of Sandmound Boulevard behind the Sand Mound Slough levee and constructed on stilts (10 feet ' high). Some older homes, however, are not constructed on stilts and living areas are located at ground level. These units are primarily single-family detached homes and range in size from small "cottage-type" units to larger 2- and 3-story homes. Some are used as seasonal or vacation homes. Multi-family residences (Willow Park Marina) and a smaller trailer park (Sandy Point) are located near the corner of Sandmound Boulevard and Mariner Road. Surrounding Area ' POPULATION Roughly 164,000 people live in the East County area, with most of the population ' concentrated in the Pittsburg-Antioch area. The project site and vicinity are located in the "Other East County," as defined in the General Plan, where fewer than 45,000 people reside. The project site is located in Census Tract 3010 (see Figure 3.1-2). The 1990 U.S. Census shows a population of 3,002 in 1,308 households, for an average of 2.14 persons per household. Most of this population is concentrated on Bethel Island and Hotchkiss Tract. For ' comparison, the 1980 Census showed a population of 2,665 in 1,175 households, and an average 2.26 persons per household. HOUSING Overall, Contra Costa County increased its housing stock by 22 percent between 1980 and ' 1990; the East County area, however, has had an increase of 48 percent during the same period. There are approximately 58,000 households in East County, most in the Pittsburg-Antioch area. 3-5 L. cc ;Tw Gn 5, cr) ca --,Y En /; �..� .:��c,- i ,.� it � �' I J-7 �j arm 1� V, MR al. all Ag ?ITPL a- cowl�! 7W OP.A It �i- 4-11 u u iL 3-6 , ' Much of the future growth in the County is planned for the East County area. In the unincorporated communities of Oakley, Bethel Island, and Discovery Bay and the City of Brentwood, approximately 29,000 homes are planned, resulting in a population increase of about 1 65,000 people. - It's estimated 1,434 housing units in the Planning Area in 1989, based on available ' County data. Of these, 1,406 were reported in use year round, with a vacancy factor of 16.4 percent; the remainder were seasonally occupied. The year-round housing consisted of 874 single-family homes, 162 multi-family homes and 381 mobile homes. Most housing is owner ' occupied. ' JOBS/HOUSING BALANCE The Countywide jobs/housing ratio is expected to reach approximately 0.74 jobs per employed resident under the General Plan. The projected jobs/housing ratio in the East County area is expected.to improve as the influx of new residents creates the demand for new services, and retail and other businesses follow the growing population base. ' In 1980,employment data for Census Tract 3010 residents showed 974 employed persons, 87 unemployed persons, and 1,175 persons not participating in the labor force. These numbers reflect the large proportion of children and retirees living in the census tract. In general, the East County area exhibits a low jobs to housing ratio indicating ' substantially more housing units than jobs. This situation results in many East County residents commuting to areas such as Concord/Walnut Creek, Livermore and other East Bay employment centers. East County also contains a relatively high proportion of retired persons due to the ' relative affordability of housing in the area. The elderly population of the area may skew the jobs/housing balance to some degree and reduce the amount of job commuting. ' GENERAL PLAN POLICIES General Plan policies establish that the County shall provide assistance for reducing the cost of low-income housing and the creation of public/private partnerships for the purposes of facilitating low and moderate income housing. To obtain a wide range of housing types, mixed-use projects and innovative approaches are encouraged. Development projects should be ' at or near density maximums to provide as much housing as possible. Area plans shall be reviewed to identify opportunities to increase densities without disrupting the character of established areas. To the extent possible, rapid growth areas should be developed so as to ultimately provide a balance of new residential and employment opportunities (Contra Costa County General Plan, Chapter 6, Housing Element). 3-7 1 BETHEL ISLAND AREA ' County data indicates approximately 1,050 existing dwelling units on Bethel Island and 400 existing dwelling units on Hotchkiss Tract. The General Plan limits the gross density and future population of the Planning Area by allowing a maximum of 3,200 new dwelling units. A maximum of 200 new units could be built on Bethel Island (1 unit per existing parcel); a ' maximum of 3,000 new units (minus 153 units approved, but not yet constructed) could be built on Hotchkiss Tract. Four applications for development of 2,998 residential units on 1,814 acres in Hotchkiss , Tract are now pending. Two additional projects involving 153 units on 39 acres have been approved for Hotchkiss Tract but have not been constructed. Based on the total acreage of ' Hotchkiss Tract (3,000 acres), 1,147 acres are therefore not proposed for development at this time, but could result in as many as 229 units if developed at the base density of 1 dwelling unit per 5 acres. The 153 approved units plus the 229 potential "base density" units total 382 and ' need to be set aside from the 3,000 units allowed by the General Plan, leaving 2,618 units theoretically available under the gross density limit for Hotchkiss Tract. The General Plan is flexible on the types of housing that may be constructed. However, new housing would be restricted to single-family units. New housing is expected to be in the median price range. The number of persons per household in new units is expected to increase and be more in conformity with the County average of 2.64 persons per household. The vacancy rate is expected to decline as development takes place. The General Plan seeks to provide employment opportunities appropriate to the rural and ' recreational nature of the area, with special emphasis on expanding the commercial recreational sector. ' Contra Costa Countv General Plan, 1991 The Contra Costa Count General Plan 1990 - 2005 was approved in January 1991 and ' Y PP rY presents the broad goals and policies, and specific implementation measures necessary to guide future growth,development and the conservation of resources within the County through the year , 2005. The County's land use goals, policies and implementation measures are contained in the Land Use Element of the General Plan; the County's housing policies are contained in the , Housing Element. Goals, policies and implementation measures regarding population growth are generally contained in the Growth Management Element. Specific provisions in the General Plan provide basic direction for land use in the Bethel Island Planning Area. ' The County General Plan contains the broad goals and policies, and specific implementation measures, which will guide decisions on future growth, development, and the , conservation of resources through the year 2005. 3-8 1 The General Plan contains nine Elements, or topic areas, which contain the County's goals, policies and implementation measures. The nine elements include: Land Use, Growth Management, Transportation and Circulation, Housing, Public Facilities/Services, Open Space, conservation, Safety, and Noise. ' Land Use Element The Land Use Element of the Contra Costa County General Plan defined the general distribution, general location and extent of the land for housing, business, industry and open ' space throughout the County. The Land Use Element also sets forth the County's goals, policies and implementation measures regarding the use of lands within the County. The General Plan designates two land uses for the project site: Agricultural Lands (AL), covering most of the site, and Open Space (OS), covering the drainage channel traversing the ' site. These designations have an "Off-Island Bonus Area" overlay (see Figure 3.1-3). Agricultural Lands (AL): ' The Agricultural Lands designation permits 1 dwelling unit/5 acres and includes non-prime agricultural lands in flat East County areas. Some, including the project site, are included in the 100-year flood plain, as mapped by the Federal Emergency Management Agency (FEMA). The uses that are allowed in the AL designation include all land-dependent and non-land dependent agricultural production and related activities. With respect to the Off-Island ' Area, development under this designation, to the extent permitted beyond 1 unit/parcel, should be clustered with development rights on the undeveloped land dedicated to the County. Open Space (OS): This General Plan designation includes publicly owned, open space lands which are not ' designated as "Public and Semi-Public," "Watershed," or "Parks and Recreation." Lands designated "Open Space" include, without limitation, wetlands and tidelands and other areas of significant ecological resources,or geologic hazards. The "Open Space"designation also includes privately owned properties for which future development rights have been deeded to a public or private agency. The most appropriate uses in "Open Space" areas involve resource management. Other appropriate uses are low intensity, private recreation for nearby residents. The construction ' of permanent structures, excluding a single-family residence on an existing legally established lot, not oriented towards recreation or resource conservation, is inconsistent with this open space designation. 3-9 1 as- rV PR SH WA -CR T l: A C T C. r.R MWO AL b� os _ '• h _=r s - - c� � AL ` ! ML _ -PA_ AN 0 \~ .r '.Y`\ \ •.JCLSCO,R •' ..�. _ DR - SLw ,rt .. •. rix ! '''Y. ♦.a? � SL .. _ . .- 2 CO � .. _ .... - .._. OS ML • _ HnLLA Ott" TR AL ; MQ M$ M8 fm g t � y - DR _ - a Project Site M$ AL -os zo '/ t. A b r 6 ." PS _ mm _ .._ .._. _. 0S , SL vs ... ... ..� ...........y.. ......_.. — ... .. r ALi CO -SM .A: : DR , T AL s Off Island Bonus Area oS _ Figure 3.1-3: CYPRESS LAKES & Contra Costa County General Flan COUNTRY CLUB PROJECT Land Use Designations in Project Area Source: Contra Costa County 3-lU , Off-Island Bonus Area: The Off-Island Bonus Area is identified for the Hotchkiss Tract. The base density of this area is I dwelling unit per 5 acres and shall be increased through the bonus program if the applicant participates in one of the following programs: ' Recreational Proiects. Residential projects which include a distinct, identifiable recreational character by including substantial recreational facilities shall be allowed a density of 1.0-2.9 units per net acre. Recreational amenities may include marinas or ' launching areas off the project site on Sand Mound or Rock Sloughs, a lake community, a sailingiboating club on a project lake, an equestrian facility, a tennis club or golf course. Purchase of Development Rights. The development rights for one acre increments of land in the County with an Agricultural Land designation may be purchased and dedicated to ' the County to increase the base density up to 1/2 dwelling unit per net acre. Acquiring development rights in one acre increments of land in the County with an Agricultural Core designation will increase the base density up to a maximum of 3 dwelling units per net acre. The term "net acreage" includes all land area used exclusively for residential purposes, and excludes streets, highways, and all other public rights-of-way. Net acreage for residential densities is assumed to constitute 75 percent of gross acreage for all uses, except for the multiple family designations, where it is assumed to comprise 80 percent. However, actual measurements used on an application may be based on analysis of the proposed development site plan. Unique environmental characteristics may justify a reduced number of units or intensity of use than is normally allowed under the General Plan designation. ' All Agricultural (A) Zoning Ordinance Districts are consistent with the preceding land use designations. The Planned Unit District (P-1) zoning district may be found to be consistent with ' these land use designations under certain circumstances. Urban Limit Line and 65/35 Land Preservation Standard: ' Measure C - 1990 affirmed community support for the Urban Limit Line (ULL) and established a 65/35 Land Preservation Standard. The purpose of the ULL is to: 1 ensure reservation of identified non-urban agricultural, P rP ) P g , open space and other areas by establishing a line beyond which no urban land uses can be designated during the term of the General Plan; and 2) facilitate the enforcement of the 65/35 Land Preservation Standard which requires that 65% of the County reflect non-urban uses. ' Properties, such as the project site, that are located inside the ULL would be governed by the land use designations contained in the General Plan. 3-11 Development of property within the ULL is-restricted by the limitations imposed by the r County's Growth Management Program, as well as by other General Plan limitations. If land is developed within the ULL, a substantial portion of this land shall be retained for non-urban uses such as open space, parks, recreational uses and public facilities. These non-urban uses within the ULL shall be considered "non-urban" in monitoring the 65/35 Land Preservation Standard, and shall be applied within the ULL on a Countywide basis as it may be more or less , applicable to various development projects within the ULL. Of the total land area of 219,000 acres within the ULL, about 144,000 acres are currently designated for urban use. The 65/35 Land Preservation Standard requires that at least 65 percent of all land in the , County shall be preserved for agriculture,open space,wetlands,parks,recreation,public facilities and other non-urban uses. The standard ensures that both within and outside the ULL, a maximum of not more than 35 percent urban development could occur in the County. Other non-urban land use designations generally considered under the 65/35 Land Preservation Standard include public/semi-public uses such as schools, public offices, highways and major flood control , rights-of-way, and railroads. Land Use Policies: ' Land use policies which are applicable to new development including the proposed project, are listed on pages 3-43 through 3-45 of the County General Plan. In general these policies are broken into four sub areas: Jobs/Housing Balance; Growth Management, 65/35 Land Plan and Urban Limit Line; Community Identity and Urban Design; and Residential uses. The following are specific land use policies which would apply to the proposed project: ' • New development within unincorporated areas of the County may be approved,providing growth management standards and criteria are met or can be assured of being met prior to the issuance of building permits in accordance with the growth management element. (Policy 3-5) • Development of all urban uses shall be coordinated with provision of essential al community services or facilities including, but not limited to, roads, law enforcement and fire protection services, schools,parks, sanitary facilities,water and floor control. (Policy 3-6) , • The location, timing and extent of growth shall be guided through capital improvements programming and financing (i.e. capital improvement program,.assessment districts, impact fees, and developer contributions) to prevent infrastructure, facility and service deficiencies. (Policy 3-7) • Preservation and buffering of agricultural land should be encouraged as it is critical to maintaining a healthy and competitive agricultural economy and assuring a balance of , land uses. preservation and conservation of open space, wetlands, parks, hillsides and ridgelines should be encouraged as it is crucial to preserve the continued availability of 3-12 1 unique habitats for wildlife and plants, to protect unique scenery and provide a wide range of recreational opportunities for County residents. (Policy 3-12) • Water oriented recreation uses shall be permitted in East county provided that such development is compatible with the Delta's unique ecology. (Policy 3-45) The project's relationship with County Growth Management standards and criteria and the provision of essential community services are discussed in this EIR. Sections 3.9 and 3.10 of this EIR provide additional information regarding the provision of public,services and utilities to the proposed project as well as the project's relationship to the County's Growth Management policies. Growth Management Element Measure C - 1988 added one-half cent to the County sales tax to be used for transportation funding. In order to receive local street maintenance and improvement funds under Measure C, the County was required to develop a Growth Management Element, which includes: 1) traffic levels of service (LOS) standards keyed to types of land use; and 2) performance standards maintained through capital projects for fire, police, parks, sanitary facilities, water and flood control. By using the Growth Management Element to manage new development proposals, the County will ensure that development projects bear their appropriate share ' ("fair-share") of the adverse burdens and impacts they impose on public facilities and services, and that new facilities and services will be provided in a timely manner. The Growth Management Element works closely in conjunction with the Land Use Element, the ULL, and the 65/35 Land Preservation Standard, and contains implementing programs which encourage attainment of the goals and objectives of the Conservation Element, the Public Services/Facilities Element, and the Housing Element. Improvements needed to implement the Circulation and Public Services/Facilities Elements are in part directly tied to, and dependent upon, the implementation of the Growth Management Element. Policies of these individual General Plan Elements which are applicable to the proposed project are described in the appropriate Sections of this EIR (see Sections 3.2 Transportation/Circulation, 3.9 Public Services, 3.10 Utilities). Transportation and Circulation Element ' The purpose of the County's Transportation and Circulation Element is to establish transportation goals and policies and to establish specific implementation measures to assure that the transportation system of the County will have adequate capacity to serve planned growth in the Contra Costa County through the year 2005. On august 3, 1988, the county adopted the Contra Costa Transportation Improvement and Growth Management Program Ordinance ("Measure C-1988"). The Ordinance provides for a county-wide retail transaction and use tax of one half percent for a period not to exceed 20 years. The proceeds are placed in a special fund solely for a transportation, construction and planning program. The Growth Management 3-13 ■ Program requires each jurisdiction to adopt traffic level of service standards keyed to the types of land use as well as performance standards for key public services and utilities. Contra Costa County has complied with the Growth Management Program by establishing performance standards for traffic, as well as other services and utilities, as specified in the Growth Management element of the Contra Costa County General Plan. Additional discussion regarding the transportation and circulation policies and guidelines applicable to the project is provided in Section 3.2 of this EIR. Housing Element , The County's Housing Element presents goals, policies and other information related to the provision of housing for existing and future residents of the County. The purpose of the Housing Element is two-fold: 1) to present specific policies and actions for housing provision, based on the premises and policies of the residential land use component of the County General Plan's Land Use Element; and 2) to provide an adopted County Housing Plan that will help the County and its political subdivision to qualify for housing aids and grants (General Plan, page 6-1). Public Services/Facilities Element cilities Element establishes the goals and policies that address vital The Public Services/Facilities g infrastructure and public services that must be provided to maintain the quality of life of existing and future Contra Costa County residents. Public Services and facilities addressed in the County General Plan that would apply to the proposed project include: water service; sewer service; drainage and flood control; public protection; fire protection; solid waste management; schools; and child care. Additional discussion regarding Public Services/Facilities policies applicable to the proposed project are contained in Sections 3.9 and 3.10 of this EIR. Open Space Element The Open Space Element of the Contra Costa County General Plan contains goals, policies and implementation measures regarding scenic resources, historic and cultural resources, and parks and recreation. The project's relationship with the County's policies regarding scenic resources is discussed in Section 3.5 (Visual Quality) of this EIR. The project's conformance with the County's policies regarding parks and recreation are discussed in Section 3.9 of this EIR. Conservation Element The Conservation Element of the County General Plan identifies the County's natural resources and sets forth goals and policies for their preservation and management. Topics addressed in the Conservation Element which are directly related to the proposed project include: vegetation and wildlife; agricultural resource; soil resources; and water resources. Additional 3-14 ' discussion regarding specific policies from the Conservation Element applicable to the project is contained in Section 3.8. Safety Element The Safety Element of the County General Plan includes map of known hazards including ' seismic and other geologic hazards located within the County. With respect to new development, the Safety Element sets forth policies regarding seismic, ground failure and landslide hazards. Policies from the Safety Element applicable to the proposed project are discussed in Section 3.8 ' of this EIR. ' Noise Element The Noise Element of the County General Plan analyzes and quantifies the current and projected noise levels from various sources in the county including: highways and freeways; ' arterial and local streets; railroads and rapid transit; industrial plants; and other stationary sources. The policies of the Noise Element are intended to mitigate noise problems in the County. Policies from the Noise Element applicable to the proposed project are discussed in Section 3.6 of this EIR. Policies Related To The Bethel Island Area The General Plan contains policies for the Bethel Island Area which is comprised of Bethel Island (on-island area) and Hotchkiss Tract (off-island area) in which the project site is located. These two areas differ with respect to soils, topographic and geographic conditions, and levee stability, and thus are given different development and planning considerations, with those for Hotchkiss .Tract being the less restrictive. In addition to the Off-Island Bonus Area designation,the following Land Use Element policies are applicable to development on Hotchkiss Tract: • The approval of new development shall be limited to 2,909 primarily recreation-oriented units in the off-island area (i.e., 3,000 additional units including the 91 units already approved, but not yet built). (Policy 3-69) • Any internal levees must meet Army Corps of Engineers' standards. New construction must be set back from levee centerline a minimum of 100 feet unless adequate substantiation for reduction is approved by RD-799 or BIMID. New construction not protected by certified levees must meet FEMA standards. (Policy 3-74) • Residential development on Agricultural Lands, to the extent permitted beyond one unit per parcel in the off-island area, shall be clustered with development rights on the undeveloped land dedicated to the County. (Policy 3-79) 3-15 • A Protection Fee shall be imposed on each new residential unit in the Bethel Island Area , to acquire development rights on agricultural lands, open space or wetland areas, or to provide financing for farmers to continue agricultural production. Priority for the acquisition of open space and wetlands shall be given to the on-island area. Additional funding sources shall be explored to supplement or replace the Protection Fee. (Policy 3-80) , Delta Protection Legislation (SB 1866) Johnston The Delta Protection Act was signed by the Governor on September 24, 1992, and , becomes effective January 1, 1993. The Delta Protection Act relates to the preservation and protection of the Delta, its natural resources, agriculture, recreation opportunities, levees, ports ' and historical value. The Act, creates a 19-member Delta Protection Commission (DPC) comprised of State and local officials. By July 1, 1994, the DPC is required to adopt a long-term regional plan for the Delta Area. The regional plan controls land within the boundaries of the delta, as described in Section 1220 of the Water Code, but which are not within either the urban limit line or sphere of influence of any local government general plan ("primary zone"). The regional plan does not apply to land within the "secondary zone" which is defined as all delta land and water areas within the boundaries of the Delta not included in the primary zone and subject to the land use authority of local governments. The Act does not require a local general plan in the secondary zone to conform to the regional plan. Local governments with lands in the primary zone must conform their general plans to the regional plan. Prior to the adoption of the regional plan, local governments may only approve development within the primary zone after making specified findings relating to the impact the development will have on the primary zone. Development is defined to exclude agricultural related activities, levee work, and maintenance dredging and work related to ports and marinas. Zo_ nine ' The majority of the project site is zoned A-2 (General Agriculture) which has a minimum , standard of 5 acres per parcel. A small portion of the site south of Cypress Road (southeast corner of the project site) is zoned A-3 (Heavy Agriculture) which has a minimum parcel size of 10 acres. IMPACTS The following impacts discussions address the projects impacts to the existing land uses of the project site; the project's indirect effects on surrounding land uses; the impacts of other planned land uses in surrounding areas; the project's impact on population and housing; and the project's relationship to the County General Plan. --3-16 ' Impacts to Existing Land Uses The proposed Cypress Lakes project would replace agricultural and rural residential use ' of the site with single,family residential and recreational uses and levees. Table 1-1 in Chapter 1 provides a breakdown of the proposed project's land uses and the acreage devoted to each. This change is consistent with the land use designations and goals of the Contra Costa County ' General Plan. The removal of the project site from agricultural production would not be considered a ' significant impact because the project area is designated for some urban development and the soils in the project area are not considered "prime". However, the conversion of the project site to urban and suburban uses would contribute to the incremental loss of agricultural/open space land throughout Contra Costa County. Such incremental loss has been limited through establishment of the urban limit line, the 65/35 Land Preservation standard, and the agricultural core areas, so that this impact is not considered to be significant or adverse. Construction of the project would also require the removal of eight of the existing residences and other structures located on the project site. The project applicant owns all eight residences proposed for removal. These residences are primarily located along Cypress Road east of Bethel Island Road and include the Dal Porto home and ranch located off Bethel Island Road just south of Sandmound Boulevard. Not included within the project boundaries but surrounded by the project site are three existing residences which would remain. These residences are located south of Cypress Road east of Bethel Island Road. These residences and the associated property ' would remain under their present ownership, but would ultimately be surrounded by the proposed project. This situation would not result in incompatible land uses because the new surrounding uses would be residential. ' Development of the proposed project would place residential uses in close proximity to large electrical transmission lines (WAPA and PG&E lines), potential natural gas drilling sites (five drilling easements are located on the project site), adjacent agricultural uses and downwind of industrial uses (note: industrial uses are located in the City of Antioch approximately 6 miles west of the project site). With respect to electrical transmission lines, homes are proposed ' adjacent to only the WAPA easement. The WAPA easement is 200 feet wide with the transmission lines to be located within the middle 25 feet. The PG&E line is located at the southwest corner of the project site outside the proposed internal levee system. Adequate setbacks are included in the easements. While these uses are present in adjacent and nearby areas, the proposed project would not be considered incompatible with these uses. However, project residents should be notified regarding the human health issues which may be related to these adjacent uses upon purchase of a home. Section 3.11 Human Health provides additional discussion of this issue. 3-17 Impacts to Existing Off-Site Uses ' The proposed project would create a suburban residential/recreational community in an area that is primarily agricultural and rural residential in character. There are some more suburban type uses which line the existing levee system primarily along Sandmound Boulevard. The indirect effects of this change include short-term and long-term impacts. Examples of these impacts include increased traffic, dust, noise and vibration during each phase of construction as well as long-term impacts, such as increased local and visitor traffic, noise and air quality impacts. These impacts are discussed in great detail in their respective Sections of this EIR. The ' change in community character would not be considered a significant impact because.the project site is within the County's Urban Limit Line and therefore planned for some level of development. This change is implicit in, and consistent with, the County's policies encouraging more intensive residential and recreational use of the area. The proposed project has been designed to reduce potential impacts on off-site uses by incorporating the following features: • The provision of substantial open space including a 170 acre golf course, 33.77 acres of park land, 5.6 acres of pedestrian trails and paths and 60 acres channels and lake. • Landscape buffers between residential uses and adjacent agricultural uses (i.e. landscaped levees). • Landscaped areas (around and inside the project), shall be similar to the existing , rural setting. Vegetation would be kept low and consist predominately of grass and wildflowers with some introduced shrubs and trees. Trees would be planted , along the project perimeter to screen the levee system from off-site locations. Landscape features of the project are discussed in Section 3.5 of this EIR. Impacts of Other Planned Uses in Surrounding Areas County' General Plan olicies would permit similar suburban-type ' y p p ype residential and recreational development in the remainder of Hotchkiss Tract up to the maximum allowable ' number of new dwelling units. Applications are pending at the County for three other. residential/recreation projects that, if approved, would occupy a total of 1,129 acres in Hotchkiss Tract absent an amendment to the General Plan. Their total acreage combined with that of the proposed project would be 1,814 acres. However, their combined number of approximately 2,998 i residential dwelling units, plus the 382 units set aside for already approved projects and potential "base-density" units, exceeds the number of new dwelling units allowed by the County General , Plan. Therefore, for all projects proposed for Hotchkiss Tract to be approved, with all the requested units, or further residential development in Hotchkiss Tract to be approved, an amendment to the Plan must be requested and granted.by the Board of Supervisors. , 3-18 ' ' New residents and visitors to the area can be expected to patronize the existing local- and regional-serving businesses in the Planning Area. This could be a beneficial impact on these businesses. Additional commercial uses are proposed by the General Plan in Hotchkiss Tract to support this new development. A total of 39 acres of new commercial acreage would be added to the existing 2 acres of commercial area. ' The proposed project plus other pending projects would have a significant effect on the existing rural residential uses along Cypress Road. The developments would substantially change ' the predominant land use of the area from agricultural to suburban-type residential and recreational uses (described in Section 3.5 Visual Quality of this report). Residents would experience an increase in traffic levels (described in Section 3.2. Traffic) and noise levels (described in Section 3.4. Noise). The conversion of non-prime agricultural land to these uses would not be considered a significant impact on a project level or cumulatively, and would be consistent with County General Plan policies. The project applicant would be required to pay a Protection Fee on each new residential unit which would be used by the County to acquire development rights from selected, important agricultural land or to provide financing for farmers to continue agricultural production. Impacts on Population and Housinp, Proiect Site HOUSING The proposed project would add 1,330 new dwelling units to the existing housing stock. The project homes are expected to range in cost from $175,000 to $400,000. The upper end of housing costs are for custom built homes which would constitute approximately 25% of the project. The number of new units is below the 2,909 new units allowed by the General Plan including a reduction to allowed base densities of one unit per five acres on properties that are not developed or/and underdeveloped. The project is consistent with the General Plan policy that development projects should be at or near density maximums to provide as much housing as possible. The proposed project would require the removal of 8 existing residences on the site, resulting in a net increase of 1,322 residential units and 3,228 persons. iThe proposed project would contribute in-lieu fees for affordable housing of$3,333 per dwelling unit constructed, and in-lieu fees for the County's homeless fund. The project applicant ' may consider providing all, or a portion, of the project's affordable housing requirements on-site by designating and constructing affordable units as part of the project. 3-19 f POPULATION Project characteristics of the proposed project differ substantially from the existing housing and occupancy conditions. A basis for estimating population generated by the proposed project is provided by the community of Discovery Bay, a water-oriented residential development about 15 miles south of the project site. 1990 U.S. Census data for Discovery Bay shows a population of 5,351 residents in 2,085 households, with an average of 2.57 persons per household.. Using this persons per household factor and a 5 percent vacancy rate, the proposed Cypress Lakes project would add about 3,247 persons to the population of Census Tract 3010. JOBS 1 The proposed project would create jobs in its recreational uses (golf course, beach club) and other uses such as the child care facility, fire station and school site. Other jobs may be created for project maintenance of wetlands, levees, parks, streets and lighting. In addition, construction of the project would create short-term (estimated 10-years)construction jobs. Wages for these jobs would range from minimum wages to professional wages. JOBS/HOUSING BALANCE f The proposed project is predominately residential with associated recreational facilities. While the project would create a number of jobs, the majority of project residents would need to travel off the project site to work. The primary job centers which would serve the project site include the Concord/Walnut Creek area, Bishop Ranch, Hacienda Business Park, and other job f centers in the east bay. On a long term basis, increased residences in East County will result in increased services and attract more jobs to the area, improving the long term jobs/housing balance for East County. However, in the short-term the project would contribute to East County's existing jobs/housing imbalance. The project applicant is proposing to market a portion of the project to retired persons which could reduce commute traffic and the environmental impacts associated with additional housing development in East County without comparable employment development in the area. Surrounding Area , HOUSING f The proposed Cypress Lakes project, plus three other projects with applications Pending at the County, would add approximately 2,998 new residential units and approximately 7,320 ' additional persons to Census Tract 3,010, minus the existing units that would be removed and residents that would be displaced by the project(s) (see Table 3.1-1). 1 3-20 f i The total number of housing units is projected to be 5,136 including the 2,909 new dwelling units authorized under the General Plan. Development under the General Plan would result in a diversity of housing stock from lower income units to high income custom homes. ' POPULATION As indicated in Table 3.1-1, the estimated population increase as a result of the proposed project and other projects in surrounding areas would total approximately 7,320 persons. The ' total population of the Planning Area is projected to be 11,710. This is a significant increase in the existing population of the planning area which is approximately 3,002 persons. 1 Table 3.1-1 ' Development Projects Pending for Hotchkiss Tract, August 1992 Proiect Name Dwelling Units Residents* ' Cypress Lakes 1,330 3,247 Lesher Landing 1,079 2,634 South River 575 1,403 North State Development 14 36 Total New Units 2,998** 7,320 * Based on 2.57 persons per household and 5 percent vacancy rate. ** Exceeds number of 2,909 new dwelling units allowed under the General Plan when added to 398 "set-aside" units (approved but not constructed plus potential base density units) JOBS ' Total employment within the planning area is projected to be 1,114 persons. This includes employment generated by the estimated 100,000 square feet of commercial uses, and 500 hotel rooms that would be allowed under the General Plan. Development under the General Plan would substantially increase the opportunity for residents to secure local employment and attract employees and visitors from outside the Planning Area. JOBS/HOUSING BALANCE Build-out of the planning area as envisioned under the County General Plan would result in the provision of needed mixed-housing at reasonable cost for Contra Costa County and the region; the provision of needed and desired recreational opportunities for the County; and the 3-21 provision of additional employment opportunities in commercial and recreational projects. However, it is not expected that build-out of the Bethel Island planning area will result in a balance of jobs and housing in the short term. Most residents will commute to other portions of Contra Costa County in addition to other job centers in the East bay, the Bay Area and Solano County. In the long term, more residents in East County are expected to attract more fobs to the area and improve the job/housing balance. , Relationship to Contra Costa County General Plan Land Use Element ' The applicant for the proposed Cypress Lakes project has requested the rezoning of the ' 685.9-acre site from General Agricultural (A-2, 5 acre minimum parcel size and A-3, 10 acre minimum parcel size) to Planned Unit District (P-1) to allow the uses proposed in Table 1-1. The P-1 zoning district could be considered consistent with the General Plan land use , designations of the project site, i.e., Agricultural Lands (AL) and Open Space (OS) and Off- Island Bonus Areas (See discussion under Zoning, below). Parks and Open Space: The General Plan designates the major drainage/irrigation ditch on the project site as Open Space. The project is proposing to enhance the ditch by widening it to approximately 50 to 100 feet wide to accommodate additional wetlands and wildlife. Consistent with the County's Conservation Element policy, a 100' setback from the centerline of the channel would be , provided (see Section 3.8 of this EIR). The applicant proposes the development of 33.77 acres of park land. Twenty acres will be dedicated to the County as a neighborhood park. The additional acreage is dispersed through- out the project. The neighborhood park will consist of baseball and soccer fields. This acreage exceeds the County General Plan park dedication requirements of 4 acres per 1,000 new residents. The proposed project would include a system of bicycle/pedestrian trails throughout the , project site. These trails would consist of the following: 1) An east/west bicycle/pedestrian trail along the primary drainage channel on the project site. This trail would wind through the golf course and be used by golf carts as well as bicycles and pedestrians; 2) On-street bicycle lanes along the portion of Cypress Road within the project site and along the primary north/south roadway to be constructed through the project; and, 3-22 ' ' 3) A major trail, consisting of an 8-foot paved path, along the top of the proposed levee system. This trail would connect all bicycle and pedestrian paths within the project site (see Figure 3.9-4). The proposed trailsystem is consistent with the conceptual trail plans in the County ' General Plan. Additional discussion of the proposed recreational facilities and trail system is contained in Section 3.9 of this EIR. Off-Island Bonus Area: The applicant's proposed residential density is consistent with the provisions of the Off-Island Bonus Area. The project's overall density of 2.21 dwelling units per net acre falls within the 1.0-2.9 dwelling units per net acre allowed by the Off-Island.Bonus Area. This density of 2.21 dwelling units per net acre is based on the total acreage of the site (685.9 acres) ' minus public and private easements and circulation improvements (85 acres) for a net total of 600 acres. The net total includes 242 acres proposed to be used exclusively for residential purposes. ' The recreational component of the proposed project (semi-private golf course, beach club, lake, and enhanced channel) is consistent with the types of recreational amenities encouraged by the General Plan in order to allow the granting of a density bonus: "a sailingiboating club on a project lake; a lake community; a tennis club; and/or a golf course." The project also proposes additional recreational amenities such as 33.77 acres of park land and 5.6 miles of pedestrian trails and paths. The proposed project conforms to General Plan Land Use Element Policies 3-69 regarding development limited to 2,909 units, 3-74 regarding internal levees needing FEMA standards, and 3-80 regarding Protection Fees in the following manner: • The project proposes 1,330 primarily recreation-oriented units, below the limit on new development; • Proposed levees will meet FEMA standards; • Each new unit will be subject to a Protection Fee for the preservation of agricultural land and production and wetlands. ' Urban Limit Line and 65/35 Land Preservation Standard: The proposed project is located within the established Urban Limit Line (ULL), which establishes those areas of the County which can be developed with urban uses and those which should not be to ensure compliance with the goals of the 65/35 Land Preservation Plan. The proposed project would further this goal by developing 365 acres (53%) of the 685.9 acre site as open space, wetlands, parks, recreation and other non-urban uses, such as the school site and major flood control rights-of-way. 3-23 r Land Use Policies: The project generally complies with the County land use policies for the following reasons: • The project site does not contain prime agricultural soils; • The project would be subject to the County Protection Fee for protection of agricultural land and wetlands; , • The project design avoids where feasible and replacing those impacted in a ratio of 3 acres to every 1 acre impacted; • The project would enhance the privacy ditch into a channel and provide an additional channel for wildlife habitat; , • The project includes a 170 acre golf course and 33 acres of public and private parks. Growth Management Element: Conformance with the various Growth Management standards contained in the Growth Management Element of the County General Plan is discussed in the appropriate sections of this EIR (Section 3.2 Traffic and Circulation, Section 3.9 Public Services, and Section 3.10 Utilities). The proposed project's conformance with the Growth Management Element's performance standards for fire, police, parks, sanitary facilities, water and flood control are discussed in Sections 3.9 Public Services and 3.10 Utilities. Most costs of the development would be borne by the applicant through the payment of fire and school facilities fees, and water and sewer service connection fees. The project would also include the construction (or payment of the appropriate costs) of the infrastructure necessary to serve the proposed project (i.e. water, sewer and drainage facilities). Various on-site maintenance requirements would be funded through the proposed Homeowners' Association or service districts. The applicant would also need to complete annexations of the site to the Oakley Water District and Contra Costa Water District, , and annexation of a portion of the site to the Ironhouse Sanitary District so that water and sewer services could be provided to the entire site. The Oakley Water District and Ironhouse Sanitary . District have both indicated that they would be willing to serve the proposed project if annexed, ' that capacity will be available; both have provided "will serve" letters to the project applicant. In addition, conformance with the Growth Management Element, the project proposes to remove the site from the 100 year floodplain by constructing a FEMA certified levee system around the project (see Sections 3.7 Hydrology and 3.10 Utilities). , 3.24 ' Transportation and Circulation Element Conformance with the Transportation and Circulation Element of the Contra Costa County General Plan is discussed in Section 3.2 of this EIR. In general, the proposed project would comply with the Transportation and Circulation policies of the Contra Costa County General Plan. Housine Element ' The proposed project is generally consistent with the County's Housing Element because the proposed project is generally consistent with the County's General Plan Land Use Map which designates the site as Off-Island Bonus Area (1.0-2.9 dwelling units/acre). The proposed project would result in the development of fewer homes on the site than can ultimately be allowed(1,330 proposed units versus approximately 1,900 units). This loss of future housing opportunity would not be considered a significant impact because the County has significant amounts of vacant land designated for residential development. In addition, the proposed project would contribute an "In- Lieu" affordable housing fee of$3,333 per approved residential home. Based on 1,330 units this fee would generate approximately $4,432,890 for use by the County in developing additional affordable housing. Public Services/Facilities Element The project's relationship with the policies contained in the Public Services/Facilities Element are discussed in Section 3.9 Public Services, of this EIR. Open Space Element In general, the proposed project is generally consistent with the policies contained in the Open Space Element by including 33 acres as depicted in Figure 3.9-4. In addition to developed 1 park land, the project would include 170 acres of golf course and 61 acres of channels and lake. Conservation Element The project's relationship with the policies contained in the Conservation Element are discussed in several areas of this EIR. The project's relationship with policies regarding ' vegetation and wildlife, and water resources are discussed in Section 3.4 of this EIR. The project's relationship with policies regarding soil resources is discussed in Section 3.8 of this EIR. In general, the proposed project is consistent with theP olicies contained in the Conservation Element. The project includes preservation of much of the existing wetlands on ' site and will replace all wetlands impacted by the project in a ratio of 3 to 1. In addition, the existing drainage ditch will be enhanced and another channel will be constructed to improve wildlife habitat. 3-25 r Safety Element The project's relationship to the applicable policies contained in the Safety Element is discussed in Section 3.7 Hydrology and Drainage and 3.8 Soils and Geology. In general, the project is consistent with County policies regarding geotechnical evaluations and floodplains. Noise Element The project's relationship to policies contained in the Noise Element is discussed in Section 3.4 Noise of this EIR. The project would be generally consistent with the County's , policies regarding noise because noise levels on the project site would be within normally acceptable levels for single family residential development (CNEL of 60 dB or less). The project would contribute to cumulative noise impacts along Cypress Road, but would be required to contribute to mitigation of this potential impact. Relationship to the Delta Protection Act of 1992 , The project site is located in the defined portion of the Delta, known as the secondary zone. The Delta Protection Act does not mandate local governments to conform their general plan or land use entitlement decisions to that of the regional plan for lands within the secondary zone. Thus, the General Plan will continue to be the controlling land use document for lands in the secondary zone and thus, the project site. Relationship to Zoning The applicant is requesting a rezoning of the site from A-2 (General Agriculture, 5 acre minimum parcel size) and A-3 (Heavy Agriculture, 10 acre minimum parcel size) to P-1 (Planned Unit District). The P-1 zoning district could be found consistent with any of the General Plan designations under certain circumstances, depending upon the specific use that is proposed. The P-1 district is intended to allow flexibility in the relationship of various buildings, structures, lot sizes; and open spaces while ensuring compliance with the General Plan and County codes and standards that protect public health, safety and general welfare. , MITIGATION MEASURES The following mitigation measures are proposed by the project applicant: ' 3.1-1 The project will pay a in-lieu affordable housing fee equal to $3,333 per residential unit. This fee should be paid at the time of issuance of building permits for the project. As an alternative to the fees, the project applicant may construct a portion or all of the affordable housing units on-site. If this alternative , mitigation is selected, the location and design of the affordable units should be submitted to the County for review and approval prior to filing final subdivision maps. , 3-26 3.1-2 The project marketing should be oriented toward seniors and retired people to reduce commute traffic from the project. While marketing of the proposed project toward seniors, the project would still worsen East County's Jobs/Housing balance. This impact of the project would be unavoidable in the short-term until additional business and jobs are attracted to the East County area. 3.1-3 A Protection Fee shall be paid for each residential unit within the project to acquire development rights on agricultural land(and open space or wetlands areas) or to provide financing for farmers to continue agricultural production. The fee shall be determined by the County and paid upon the issuance of building permits for the project. 3.1-4 The project will pay an in-lieu contribution to the County Homeless Trust Fund. ' The amount of the contribution will be determined by the County and paid, pro- rata, upon the issuance of building permits. ' Additional mitigation measures are proposed to reduce the project's impact in other areas (e.g.),Transportation/Circulation (Section 3.2), Air Quality (Section 3.3), Vegetation and Wildlife (Section 3.4), Visual Quality (Section 3.5), Noise (Section 3.6),Hydrology and Drainage (Section 3.7), Geology, Seismicity and Soils (Section 3.8), Public Services (Section 3.9), Utilities (Section 3.10), Human Health (Section 3.11), Cultural Resources (Section 3.12), and Energy (Section 3.13). The reader is referred to these sections of the EIR for specific mitigation measures applicable to the proposed project. 3-27 3.2 TRANSPORTATION/CIRCULATION , The following traffic analysis was prepared by Abrams Associates. EXISTING SETTING REGIONAL ACCESS ROUTES Regional access to the project site is provided by State Route 4 (SR 4). In the vicinity of the project, SR 4 is a two lane roadway connecting Stockton and Oakley. Recent new projects have improved and widened State Route SR 4 in both Brentwood and Oakley to four lanes. To the west of Oakley, SR 4 becomes to a four-lane freeway and continues at that width through the City of Pittsburg. In future years, it is anticipated that the Delta Expressway will replace the existing arterial portion of SR 4 to serve through traffic. Between Willow Pass Road and Bailey Road, SR 4 climbs to a summit at Willow Pass. This location represents a critical traffic congestion area for SR 4 between Concord and Oakley. The steep roadway grade approaching Willow Pass reduces the capacity of the roadway at the point which traffic volumes reach a maximum on the facility. This high volume-to-capacity ratio causes congestion during peak periods. This roadway will be under construction starting in 1992, and would be completed before the project is occupied. LOCAL ACCESS Local access to the project would be from Bethel Island Road, Cypress Road, and Sandmound Boulevard. Cypress Road connects the project site to the regional highway system (SR 4). A new traffic signal and intersection improvements have recently been completed at SR 4. Other local streets which could be affected by this project are Knightsen, Sellers, O'Hara, Empire and Rose Avenues, and Delta and Laurel Roads. EXISTING TRANSIT SERVICE e There is no existing bus transit service in the Bethel Island Area. Tri Delta Transit serves eastern Contra Costa, with service primarily oriented to Antioch and Pittsburg. The nearest Tri Delta Transit bus lines are on SR 4, where there is a route from Brentwood to Central County. Existing Roadway Conditions The location of the project and the principal roadways that would serve the project are shown in Figure 3.2-1. The principal access to the,project will be Cypress Road, which is currently a two-lane undivided roadway which extends from Bethel Island Road to Empire , Avenue. Figure 3.2-1 also shows the seventeen study area intersections that have been analyzed in this EIR. The locations have been.chosen in coordination with County staff, and represent all the critical intersections that could be significantly impacted by this project. 3-28 v a Bethel lis 5 Island Gateway Rd 1211 0 Dutch R ous Project to s Oakley Site Oakle Rd 8 7 N � 6. ..low. 4 Cypress Rd Cypress Rd 2 ' T oGG Laurel Rd 14 16 a 16 13 4 fb Knightsen 1 FO Delta Rd Is r F \R ly Rd i Lone Tree Way � V Sunset Rd s F � F a i a � saw Brentwood Chestnut St � y F F a a + a �ti 3 4 a Marsh oak Rd -----" -Future Roadways a 17 • -Intersections to be studied Cypress Lakes EIR Figure 3.2-1 Project Location Traffic Analysis Study Area Traffic Impact Study Abrams Associates 3-29 Cypress Road intersects with SR-4 east of Oakley at a recently improved four-leg , intersection controlled by a traffic signal. There is an at-grade railroad crossing on Cypress Road just to the east of SH 4. The intersections on Cypress Road with Sellers and Knightsen Avenues are controlled with stop signs for the minor approaches and are marked with flashing lights. There are frequent driveways fronting on Cypress Road, and on the segment between Jersey Island Road and Bethel Island Road there are over 30 driveways. Cypress Road has a generally straight alignment and good pavement surface. Cypress Road is 24 feet wide with 4 -8 foot shoulders and a speed limit of 50 mph in the project vicinity. The speed limit on Cypress Road in the residential areas of Oakley, west of SR 4, is 25 mph. State Route 4 is one of the major east-west roads crossing the delta in this area. In the project vicinity it is a two-lane undivided roadway which is oriented in a north-south direction to the south of Cypress Road for about four miles to Brentwood where it again turns east. Bethel Island Road is a two-lane undivided roadway extending in a north-south alignment , from Bethel Island south to Cypress Road. On Bethel Island itself, between Taylor and Gateway Roads, Bethel Island Road has four-lanes and is 60 feet wide. North of Gateway Road, Bethel Island Road narrows to 18 feet. All intersections along this roadway are unsignalized and speed limits are 50 mph in the project vicinity and 25 mph on Bethel Island. Bethel Island Road has generally straight alignment and good pavement surface. Sandmound Boulevard is a two-lane undivided roadway which currently serves as a residential collector for the various residences on this dead-end road. This roadway has narrow shoulders as it often runs parallel to waterways and fences. Sandmound Boulevard has generally good pavement surfaces. It has a very poorly aligned intersection with Bethel Island Road. Knightsen Avenue is a two-lane undivided roadway extending from Cypress Road south ' to Sunset Road. This roadway is a likely alternative route for southbound and eastbound drivers traveling to SR 4 eastbound toward Stockton. It will also be used by some project traffic heading towards Brentwood. Knightsen Avenue has generally straight alignment and good pavement surfaces. The speed limit on Knightsen Avenue is 50 mph. Empire Avenue is a two-lane undivided roadway extending from Lone Tree Way north to State Route 4, with the exception of a four-lane section between Bedford Lane and Laurel Road. This roadway is often used as a alternate route for drivers seeking to avoid congestion on State Route 4 through Oakley. Empire Avenue has numerous residential driveways fronting on it and good pavement surfaces. The intersection of Empire Avenue and SR 4 is controlled by a traffic signal. All other intersections along Empire Avenue are unsignalized. The speed limit on Empire Avenue is 35 mph. Laurel Road and O'Hara and Rose Avenues are two-lane undivided roadways in the , residential areas of the Town of Oakley. These roadways currently experience relatively low levels of traffic and are mainly residential collectors. Speed limits on these roadways are generally 25 mph. All study intersections along these roadways are unsignalized. , 3-30 Other roads that could be impacted are Sellers Avenue and Neroly Road. These roads are two-lanes in width and serve growing traffic volumes. Sellers Avenue connects from Cypress Road to SR 4.east of Brentwood, and is a north-south alternative to SR 4. Neroly Road serves sections of Oakley, and is a major connection to the SH 4 interchange. ' Existing Traffic Volume Conditions The existing traffic volumes on the roads in the vicinity of the project are shown in Figures 3.2-2 thru 3.2-4. This data is based on existing 1992 traffic counts at each of the seventeen study area intersections, and on link volumes derived from this data. Data comes from counts by Abrams Associates for this project, plus counts conducted by DKS Associates for the Oakley Traffic Study and for the East County Traffic Model. Figure 3.2-2 shows the AM traffic volumes on each of the affected streets. The existing Level of Service (LOS) at each intersection during the morning commute period is also shown. In general, existing traffic conditions during the AM peak period are well below capacity on all roads in the area. All intersections operate at Level of Service "C" or better. Traffic volumes on SR 4 are at capacity in the peak direction through Pittsburg and Concord. Traffic volume data and intersection capacity information are contained in a Technical Appendices available for review at the Contra Costa County Community Development Department. Figure 3.2-3 shows the existing PM peak hour traffic on the streets affected by the project. During this time period, all intersections operate at an acceptable LOS. The intersection of SR 4 (Main Street) and Neroly Road is the most critical traffic location, with an LOS of"D" (V/C ratio = 0.86). Traffic volumes are well below capacity in the vicinity of the project, but are approaching capacity at several intersections through Oakley. The Average Daily Traffic (ADT) is shown on Figure 3.2-4. The highest traffic volumes in East Contra Costa County are on the freeway segment of SR 4 where weekday traffic can be up to 48,000 vehicle trips per day. In the vicinity of the project, daily traffic on Cypress Road is 6,200 vehicles per day, while through Oakley, the traffic volumes increase to 23,000 vpd near the freeway interchange. For this study,LOS has been calculated for the highest hourly traffic at each intersection. Traffic counts were conducted between 6:30 to 9:00 AM, and from 4:00 to 6:00 PM. The highest one hour was generally found to occur in the morning from 7:30 to 8:30 AM and in the afternoon from 4:30 to 5:30 PM. These hours correspond to the highest hourly traffic volumes on SR 4 through Oakley, although intersections located closer to Bethel Island have an earlier morning peak hour that may begin at 6:45 or 7:00 AM. Some commute traffic starts as early as 5:30 AM on many streets in the area. The average daily traffic volume on Cypress Road east of SR 4 is 6,900 vehicles per day. West of SR 4, average daily traffic on Cypress Road drops to 2,300 vehicles per day The average daily traffic on Bethel Island Road north of Cypress Road is 6,200 vehicles per day. The average daily traffic volumes were also assessed on other local streets which could be affected by the project. On Knightsen Avenue, south of Cypress Road, the average daily traffic volume is 2,100 vehicles per day. On Laurel Road, west of SR 4, 3-31 V d O � 3 WWI Slough Rd � •� oz ,r' .::.r.;.:,%4.,;:'?.F{••f)%�/fi;S..rrS?�Qywti.:;;!v{'• ' M PH PUUISI 'ipail OST' a 0££ O �1 'L� OI � .c00 �'' M �� 4:9 � Q � QO 0£� •x 08 and ua-4gSn A w 06 o LO OZ � e � � , w . any saallaS 0L Q c x o~ i N .Or d N Q O U OLE O�OSh PnIH POOMIUaig 'C ao OtS—�$ OIC /� W � 'o hany !fig obT � � OZT �JJ O E� OCZany MRO 0£I w C. OC9 \\ U OL�� 0`60_1%. PIIaIS$tfl \ O9z� —w any andtug OZ� OZ9 O� 4a INC o ti O � O 06I ���`\a V ►a l G W tv s � � In o � +, k � A ; V 4J sm A Sand MOuid Slough Rd wca . � C, riOzz s. >::>;h .!.. . O •.>..: • Gov M PS PuEIsI is aS OZI �c 09Z' O w in UI .^ b $ M a p ° CA � o 4a 'Ona N tiara O any ua-4qgnr a� o e NI �e ` w Oani/saallaS NI o r \ UIS O`OLS P^Ifl POOtAjUaig \ di 9 'd 06'g� '°u W .Xas in E u .. _M =9i�� �.o`r. ..—OCT •-� --� anb 21eH.0 osc r w C ® OIZ OSI ;ORa ..v H ULT ��,•M ddo9—T O `£I P?I �fl Sill � and andtug O� OS£TY —r oo INA OOC �O:t a� �* s A ,Z v > W N rl (+� O N O Q Z_Z'2 N r 'v O N •� rH N Sand MO►ud Slough Rd e 3 s.>; PH PuelsI IaxilaROOZ'9 'bo rt z8 �►�'( 0 0 .x N W 4a `° 0011Z a Cy and uasagSlux M 8 00I11 any siallaS " �v u V ,tiOw� 0 8'6 00Y11 PAIR POOMIUMS 06 Cany asOC0 ev , Oz any eieH.O Fj =M 006'£ OOC£ U `-4 zU OOVZ 0001Z PH 31 .18 SIR any asldW3 n � C OOS'L ee ) ' I. a � 0 w v a 3-34 average daily traffic volumes approach 2,000 vehicles per day. Lastly, on Empire Avenue, north of Cypress Road, average daily traffic volumes are 2,400 vehicles per day. ' Summer weekend traffic onto Bethel Island can occasionally be quite heavy due to boaters and other recreational activities on the Island. The most severe congestion occurs on Bethel Island itself, immediately north of the Bridge, where driveway access to various commercial activities including several marinas, interferes with through traffic. However, traffic congestion due to this phenomenon occurs intermittently, and is not a recurrent condition. For this reason the weekday commute peak hour traffic conditions are the basis on which all of the necessary roadway improvements have been determined. Intersection Analysis and Level of Service The existing volumes and lane configurations were used to determine the existing peak hour conditions and level of service at each intersection. The level of service classification system is a scale with a range of A to F. Level of Service A represents free flow conditions and LOS F represents jammed or severely congested conditions. In Contra Costa County,the Level of Service standards that are to be applied to signalized intersections not on "Routes of Regional Significance" are as shown on Table 3.2-1. It is anticipated that SR 4 will be a "Route of Regional Significance", and that all other routes will be subject to Intersections which result in a Level of Service below the established standard will need to be mitigated in order to retain an acceptable LOS. The Level of Service calculation method is the Circular 212 Planning Method except that intersection capacity has been increased to 1800 vehicles per hour to reflect actual Contra Costa County traffic conditions. Table 3.2-1 County Measure "C" Level of Service Standards Land Use Type LOS V/C Ratio Standard Rural LOS "C" 0.70 to 0.74 Semi-Rural LOS "C" 0.75 to 0.79 Suburban LOS "D" 0.80 to 0.84 Urban LOS "D" 0.85 to 0.89 CBD LOS "E" 0.90 to 0.94 3-35 The calculation procedure for unsignalized intersections is based on the Highway Capacity Manual'. This data is presented for both the intersection as a whole, and also for the most critical side street movement. Measure "C" has not established standards of significance for , unsignalized intersections. As noted, intersection traffic count data were collected for the seventeen critical intersections that would be affected by the project. These locations were selected in coordination with Contra Costa County staff, and were selected to be consistent with the traffic impact study requirements of the Contra Costa Traffic Authority (CCTA). Intersections where less than 50 peak hour trips are predicted have not been studied, such as the road system through Knightsen. Data used in this study included traffic counts from the files of the Town of Oakley and Contra Costa County, plus new counts taken by Abrams Associates. Table 3.2-1 shows the existing capacity conditions. Table 3.2-2 documents the principal existing traffic concerns in the area. Although traffic volumes are growing, the existing Level of Service is acceptable in the vicinity of the project. Traffic capacity conditions have also improved at the intersection of Cypress Road and SR 4 as a result of the recent widening and traffic signal improvements. Problems exist at the Neroly - SR 4 intersection during the PM Peak hours due to the heavy turning movements and the proximity to the freeway ramps. There are also delays and congestion problems at the Vasco Road - Marsh Creek Road four-way stop location. Future improvements are planned for both these locations independent of the projected Cypress Lakes project. Traffic Signal Warrants The need for new traffic signals at several of the unsignalized study intersections was analyzed using the Caltrans Traffic Signal Warrants. The warrants, or guidelines, are based on r consideration of minimum traffic volumes,interruption of continuous traffic,minimum pedestrian volumes, school crossings, accident experience, and a combination of these and other factors. Based on existing traffic volume conditions, the other unsignalized study intersections do not meet the minimum volumes specified in these warrants. Pedestrian and Bicycle Circulation There are few formal bicycle pathways in the Bethel Island area. Cypress Road is a typical example. The existing width of Cypress Road is approximately 24 feet with no sidewalks or other provisions for pedestrians. Other streets in the study have similar cross-sections. In 1 Highway Capacity Manual, Special Report 209, a publication of the Transportation Research Board, Washington D. C., 1985 • 3-36 Table 3.2-2 EXISTING INTERSECTION CAPACITY CONDITION SZ Z 'T'E SECTION:. .. . EXISTING flNDITIONS 1 Bethel Island Rd. at Cypress Rd. Does Not Exist A/A A/A 2 Bethel Island Rd. at Gateway Rd. All-Way Stop A/A A/A Jersey Island Rd. and Edens 3 Plains Rd. and Cypress Rd. Stop Signs on Side Streets A/A A/A 4 Knightsen Ave. at Cypress Rd. Three-Way Stop Sign A/A A/A 5 Sellers Ave. at Cypress Rd. All-Way Stop A/A A/A 6 SR4atr Cyp ess Rd. Traffic Signal 0.27/A 0.42/A 7 SR 4 at O'Hara Ave. Stop Sign at O'Hara Ave. A/F B/F 8 SR 4 at Oakley Rd. Traffic Signal 0.35/A 0.55/A 9 SR 4 at Big Break Rd. Traffic Signal 0.40/A 0.51/A 10 SR 4 at Neroly Rd. Traffic Signal 0.61B 0.86/1) 11 SR 4 at SR 160 NB Off-Ramp Stop Sign C/F C/F SR 4/E 18th St. at SR 160 SB 12 On-Ramp Traffic Signal 0.33/A 0.32/A 13 SR 4 at Laurel Rd. Stop Signs ns on Laurel Rd. A/E A/D 14 Empire Ave. at Laurel Rd. Four-Way Stop B/C B/D 15 O'Hara Ave. at Laurel Rd. Four-Way Stop B/C B/C 16 Rose Ave. at Laurel Rd. Stop Signs on Rose Ave. A/A A/A 17 1 Marsh Creek Rd. at Vasco Rd. Four-Way Stop D/D D/1) 2 For unsignalized intersections,each movement has its own level of service. The results show the overall intersection Level f Service,and the LOS for the most critical movement. The critical level generally occurs to the left tum movement from the side street. For signalized intersections,the results show the Volume/Capacity ratio and the overall intersection Level of Service. 3-37 conjunction with the traffic counts, bicycles and pedestrians at Cypress Road intersections were counted/observed during the days of peak period observations. Most of the bicyclists observed during the a.m. peak period were children riding to school. Very little recreational bicycle use was observed however, recreational bicycle traffic is expected to increase as development of the Bethel Island Area continues. Contra Costa County General Plan The Transportation and Circulation Element of the General Plana establishes the specific implementation measures to assure that the transportation system of the County will have adequate capacity to serve planned growth in the County through 2005. The proposed Cypress Lakes project is generally consistent with the land use assumptions in the General Plan, and is a similar size to the data used in the County's traffic forecasting model. This traffic forecast, therefore has been as the principal basis for estimating the cumulative traffic impacts of the project. Traffic forecasts for the Year 2005 were made using a computerized travel model, and have been reviewed for the Cypress Lakes Project. Since the model was developed, ABAG has updated the forecasts for the County with specific adjustments for the East County area. These new assumptions have been taken into account in the cumulative impact analysis. IMPACTS This section of the EIR addresses the project's travel demand and potential transportation impacts. Cumulative traffic conditions are also addressed. The implications of the additional development that will occur in the Bethel Island Area (BIA), the Oakley-North Brentwood Area (ONBA), and the Cypress Corridor are also addressed, and discussed in relation to the proposed project. Proiect Trip Generation The trip generation characteristics of the proposed project are presented in Table 3.2-3. The trip generation rates for the residential units were obtained from ITE Trip Generation, Fifth Edition, 1991, and are consistent with rates that have been assumed for other residential projects in Contra Costa County. Based on the ITE regression equation, each single-family residential house is expected to generate 7.74 vehicle trip ends, or one-way trips, per unit per day. The 1,330 houses proposed would generate 10,287 vehicle trip ends per day, including 730 trips during the AM peak hour and 1,036 trips during the p.m. peak hour. Trip generation for the 3 Contra Costa County General Plan, 1990-2005,Community Development Department.January 1991 3-38 Table 3.2-3 Cypress Lakes - Vehicle Trip Generation AM PEAK HOUR PM PEAK HOUR �O..MFONEIfi.::::<:<:::::.:.> :::::.:::::...5... .:::::::._ 1 D ':.:::: N.:::::::::..::.:....:.::::::::::::::::::::::::::..::::::::,::::::::::::. ;1 330.>:.>::;:,. 0C T Single-Family Residential Units 10,287 190 540 370 673 362 1,036 Golf Course, Driving Range, etc. -- 800 42 22 64 26 38 64 Clubhouse, -- Restaurant, etc. 550 91 2 11 22 27 50 Swim & Tennis Club -- 120 8 5 13 8 5 13 RV/Boat Storage Area -- 70 4 1 5 31 5 8 Day-Care Facility -- 130 14 8 22 7 10 17 Parks and Open Space -- 60 2 1 3 1 3 4 TOTALS -- 12,017 268 580 848 740 451 1,191 various other project components,including the golf course and clubhouse, were estimated based on previous Abrams Associates studies of similar facilities. The entire proposed project would generate 12,017 vehicle trip ends per day, with 848 trips occurring during the AM peak hour and 1,191 trips during the PM peak hour. This data reflects only vehicle trips that are external to the project. Some internal trips have been assumed for other project components, reflecting trips between the residential areas and the recreational facilities within the development. Cypress Lakes Trip Distribution The project as proposed would have two access points, one at the intersection of Cypress Road and Bethel Island Roads and another onto Sandmound Boulevard on the north side of the project. The Cypress Road intersection would be the principal point of access and would be used by about 85 of the total trips from the project. The trip distribution and traffic assignment were developed based on the existing traffic patterns at the study intersections, probable locations of employment for residents of Cypress Lakes, and local experience in traffic distribution and assignment. The estimated distribution of trips generated by the proposed project onto the existing street network is shown in Table 3.2-4. 3-39 TABLE 3.2-4 CYPRESS LAKES TRIP DISTRIBUTION NUMBER OF TRIPS < .>r: >::> Cent. a ;:: erC k. ...... . a ect..... . .. .. .a eat>:<:..... yak.. >T:<.: ;. > >:::::>::>:>::::>::::::>:;>::;: >:>:ofTri,,:::. <'> »>« DT> iiiInbou O.0 bound..................To Dtrect�4n::a#`::..:ra..:ei::::::::::::::......::::::..:.: ::::::::.::::::::.:.ps..::::::::::::::::,:::.:.::::.::::::::.:::::::::.:::::::.::::::.:: :..::... .::::::::.:::::.......tai.:. North to Bethel Island 4% 480 30 18 48 SR 4 to Antioch-Pitts 42% 5,050 311 189 500 Local Trips into Oakley 23% 2,760 170 104 274 Local Trips into Brentwood 14% 1,680 104 63 167 SR 4 toward Stockton 8% 960 59 36 95 SR 160 toward Rio Vista 4% 480 30 18 48 Vasco Rd. toward I-580 5% 600 37 23 60 Probable employment areas for residents of the Cypress Lakes project would include Brentwood and Oakley. However, the largest portion of the jobs would be located in Antioch, Pittsburg, and parts of Central Contra Costa County. Some residents may commute to Alameda County and San Francisco. This traffic analysis has not been conducted in detail beyond SR 4 in Antioch. A more complete discussion of employment location is described in -the EIR in Section 3.1. Trip assignment has been based on estimates of the minimum travel path from the project to various destination zones. The majority of traffic that is assigned to the State Route 4 freeway is assumed to use SR 4 through Oakley. Some portion of this traffic will also use other local streets within Oakley. Existing Plus Project Traffic Impacts This scenario has been evaluated for each of the intersections on Cypress Road that are located in the immediate vicinity of the project. In reality, this scenario would not take place, because of other new-development occurring in Oakley-North Brentwood, and in the Cypress Corridor. The,purpose of this scenario is to determine which roadway projects are required in the Bethel Island area prior to completion of the Cypress Lakes project, and to estimate the effect of Cypress Lakes on the timing of other projects in the Bethel Island Area. 3-40 As a result of adding the project traffic to the street network, the peak hour traffic volumes would be as shown on Figures 3.2-5 and 3.2-6. Figure 3.2-5 shows the AM peak hour traffic. As noted, there would a substantial change to traffic on Cypress Road between the project and SR 4. Beyond this location, traffic from the project would be more dispersed but would still have a significant impact on SR 4 between Oakley and the 4/160 freeway. Table 3.2- 5 shows the changes in intersection capacity that would occur as a result of the existing plus project conditions. The capacity results are based on the assumption that Cypress Road would be widened. All other intersections were calculated for capacity conditions without any additional roadway mitigation measures. During the AM peak hour, all intersections would operate at a satisfactory LOS with the existing plus project condition. PM peak hour traffic will also operate at satisfactory traffic conditions, assuming that improvements are constructed on Cypress Road. One other intersection would be critically impacted. At Neroly Road and SR 4 (Main Street), traffic conditions would change from LOS "D" to LOS "E". This is considered to be a significant impact. Mitigations are planned for this intersection as a part of development in the Oakley/North Brentwood Area, including widening the northbound approach to provide two left turn lanes. This improvement would restore the intersection LOS to "D". The peak hour traffic volumes generated at the two major entrances to the project during the peak hours are shown on Figure 3.2-7. As noted the traffic that is generated through the Sandmound Boulevard intersection is very low, and would not cause any significant traffic impacts. At the intersection of Cypress Road and Bethel Island Road, however, the impacts are quite significant, and major improvements would be required, including the installation of a new �. traffic signal. The proposed project will add significant traffic volumes to the roads in the immediate vicinity of the project. As a direct result of the project, Cypress Road would exceed capacity within the roadway limits shown on Figure 3.2-5. These roads would require reconstruction and widening at the time of project construction. These issues are discussed further under mitigation measures. Year 2000 Traffic Forecasts This scenario includes all existing development, other approved development, and other currently proposed development in the Oakley, North Brentwood and Bethel Island Areas. For areas within Contra Costa County, land use data was developed from the Current Planning Project Status Report'. This project list was obtained from County staff. For areas not in the County jurisdiction (i.e.,Brentwood and Antioch),development data was obtained from previous studies and was controlled to ABAG data. The proposed developments that have been considered include the Hancock Specific Plan,Brentwood Hills Country Club,the Blackhawk-Nunn Country 4 Developed by staff of the Contra Costa County Community Development,as updated in February, 1992. 3-41 T' d CJ ^ R 0�4 w u E V 10 Sand Mound Slough Rd a. o C7 tai .;�:. o ....:Ash>�•<�o-•}�k°vi•s�:•:•• . �+ p Of lop PH PuE[SI-Iag7agM 09I .y -d OI�� -'''�- 00 TZ f Ow bo 44 W a o `I lata and uasigSlux cn 0 0-t- N Ob ° o. o. On�. and S1aIRS �+ `O(IA� Pnlg Poonyuaig 0000- 9 $ 011 .. 3 UO �! � x u o and� O ; 0. s OZZ ON� � OOT AA -' �i O OE- 0a, .. anb RIVRO OVI >, C ` ® et o a V N I v 099 •�•M z 0 � -- " OL °�' O PH vaig Sig ` )9 ► - V� and andutg 0� OOL 00 In E o , .. OE, .�Ot`�p cdH v a 00, Q ° > O v 3-42 •o v v : Saz Mound Slough Rd c .; c-7 c C7 — CL, 4i ell `' `ti E RN PH FuptSl Ia aBCD + LO �C CO 4a er "" LT and uas3q$MI cri e � ,•� •• °�$ OSTM v� � OST O DAV Wallas Lt. U V o `t S,- 069 a OS9 �-- .d-_ PnlB PoonAluaig >, 0 06S•—�$ O� � � 8 U) cn DAV aeog `OfI 061Oct `--� Vi M OIZ' •� and e'L'H.0 F0611 w c OLI �,} OIi' a OOZ #WPM .� z -.0—CZ\ �.0-91 �.Ort P?I)paag$IS �T~ 009I ant anduag O-�-r e4 T~� a _._. E tn . `�,,�, � .',oda '"-.•--_--- � 069� , �ti�a 10 E" ►a «° }' o V ivy .. ' O O 3-43 n� M C Q W O CIA 0 6v 91 90 �•+ t� .G if, �V � �•.�, .�--- �.� ,baa �a Iva • Zg--NJw w L c. 3.44 Project, Lesher Landing, and South River Development, among others. The Cypress Corridor project on the north side of Cypress Road is not included in these traffic forecasts. The future network assumptions were the same as for the East County Subarea Model Year 2000 forecasts, which reflect all funded improvements. For unincorporated areas, this included all projects in the Capitol Road Improvement Program (CRIP). It does not include the Delta Expressway, nor the Laurel Road improvements This scenario used the peak hour travel demand model developed by DKS Associates using EMME12 software that was developed for the Delta Expressway EIR. The model performs trip generation using a cross-classification method with household and income data, and is consistent with the County model. The final data is contained in a recent traffic impact reports for new residential developments in the Oakley area. YEAR 2000 TRAFFIC IMPACTS The intersection traffic capacity results for this scenario are shown in Table 3.2-5. The estimated ADT on each roadway link and the resulting AM and PM peak hour Levels of Service at each intersection are shown on Figures 3.2-8 thru 3.2-10. The year 2000 traffic scenario requires a number of new roadway improvements in order to mitigate the impacts of traffic from new development. In general, as a result of development in the Oakley/North Brentwood area and proposed development in the Bethel Island area, the needed improvements can be constructed. The problem locations where significant impacts will occur are at the intersections in the vicinity of the SR 4/160 - Main Street interchange. These locations would be at Level of Service "F". Additional significant impacts would also occur at the intersection of Cypress Road and SR 4. The Year 2000 scenario does not include the Delta Expressway and the improvements to Laurel Avenue. All of the traffic problems that are indicated in Table 3.2-5 would be mitigated once the Delta Expressway is completed. The traffic on existing SR 4 between the 4/160 interchange and Cypress would be greatly reduced(approximately 800 vehicle trips per hour) and imuch of this traffic would be relocated to Laurel Road. This would reduce the LOS at Neroly and the other intersections to LOS "C" and "D", which would be acceptable traffic conditions. Similarly, once the Laurel Road extension and the new interchange with the Delta Expressway are completed, the intersection of Cypress Road and SR 4 would be mitigated. The Year 2000 scenario does not include the Byron Highway extension to Bethel Island Road. The Year 2000 scenario can operate satisfactorily without this connection. S Traffic Impact Study of Six Residential Subdivisions in Oakley,DKS Associates,April, 1992;Technical Appendix showing Forecast Results and LOS Calculations 3-45 v 0=4 3 Sand Mound Slough Rd 04T O 00£ x PH puelsl 10,14DO 009OZL •�,� 0I F.,a GO M M N 00 a `ZT N }� � ..._.. aAd uaS;gBtu)j cri C 061 C OZ� aAd SiallaS w � � a \N, `OSL `065 PAIg Pooeyuaig 11 Q' 0l�o Oki Q W � 00 cz q aAV OWS ON 09T �$ O LT0-4 Nr069 qv � —� —� aAd 01 H2O A w ® p OOI 09T —� V � • v v SOOT 'q v z U `T OUT u ` �U£4 O � PH vaag$6g \ ary —� U m en � J � . g v ♦`O£S ,. 4 O OFE i W � • � V C/) 0~ M °= U o a I O r Z AK � d e� 3 Sanr,lvlound Slough Rd PHEI I i OSP, fl O u s a a UZb ,d S f�.l M P a O X dL— N " ►, b. `z x N 4 tiara any u8-4ugnrA cn N lO OLT any sialRS o � u 09 \. / Pnlfl Pooe4uaifl Wit+ y � o 0T'- u 4 a. ' n:5 W opo ��'` t x O any asog � �� g� �o a U) rGi Q \ .LLI : `�I �1 p„ C Ott any HA FosT " ?, u6.4 O ~\ in g fn OIL +emM a M o � 059 ` ` La P?I�eaifl 8I nfl any auig f � 09Z 06£T Du OSS , W cu � C3 v w as<,—ro OzS a�`p w0"-r H �' i H G O GJ eC `� N F. (D O 1 O O 'v o � A4 r .. Sand Mound Slough Rd w PH PUUISI lagaa� ; V e bo A Q e� o � O ' N V 4a OOL19 x ry ata anV uas;gScu)l M On'S and siallaS w v x m w A OOI'£I OOVIi P^Ifl Poo^yuaig .� W cin ' V V cz �1 c and asog "C a^v UJeH2O OOI`£ 009'S x a 000 LT � $ .. $ rwpnTM N7 C � v Ch z 001;'OI 00 ' ISIS, P2i xeaig Siff 0091m: lN w 1. d 0 � ° W N \ 3-48 Table 3.2-5 Volume/Capacity Ratios and Level of Service 1 Comparison of Existing and Future Conditions (2) (3) Exsiting Exist+Prof Year 2000 ............ ......... .......... . ................................. ..................................... . ................................ ................... ....... ............... ........... ........... ......... ..... ................ ...... .................... X. .......... .... .. ............ .... ...................................... .. ............ W.: .. ......... .... CONTROL!.::............ .............TM .................................................... ..................................... ....... ......... .................................................... . . .. .............. .. . ....................... . ............................................................................. . ........... ........... .. ......................................................... ... ............................... ........ .... Bethel Island Rd. at ypress I Rd. N-Sig A/A A/A 0.30/A 0A01A 0.39/A 0.57/A Bethel Island Rd. at Gateway 2 Rd. St-St A/A A/A B/C B/C B/C B/C Jersey Island Rd. and Cypress 3 Rd. St-Sig A/A A/A 0.44/A 0.50/A 0.53/13 0.67/13 4 Knightsen Ave. at Cypress Rd. St-Sig A/A A/A 0.46/A 0.54/A 0.55/A 0.69/A 5 Sellers Ave. Cypress Rd. St-Sig A/A A/A 0.61/B 0.59/A 0.60/13 0.72/C 6 SR 4 at Cypress Rd. Sig-Sig 0.26/A 0.26/B 0.40/A 0.78/C 0.52/A 0.87/1) 7 SR 4 at O'Hara Ave. St-Sig A/F B/F A/F B/F 0.82/D 0.80/C 8 SR 4 at Oakley Rd. Sig-Sig 0.35/A 0.49/A 0.40/A 0.53/A 0.50/A 0.60/A 9 SR 4 at Big Break Rd. Sig-Sig 0.49/A 0.50/A 0.56/A 0.54/A 0.54/A 0.45/A 10 SR 4 at Neroly Rd. Sig-Sig 0.60/B 0.83/D 0.68/13 0.92/E 0.77/C 0.94/E 11 SR 4 at SR 160 NB Off-Ramp St-Sig C/F C/F C/F C/F 0.93/E 1.16/F 12 SR 4 at SR 160 SB On-Ramp Sig-Sig 0.33/A 0.32/A 0.36/A 0.35/A 0.61/13 OAIIA 13 SR 4 at Laurel Rd. St-Sig A/E A/D A/E A/E 0.40/A 0.49/A 14 Empire Ave. at Laurel Rd. St-Sig A/A A/A A/A A/A 0.53/A 0.62/13 15 O'Hara Ave. at Laurel Rd. St-Sig A/B A/B A/B A/B 0.32/A 0.43/A 16 Rose Ave. at Laurel Rd. St-Sig A/A A/A A/A A/A 0.17/A 0.27/A 17 , Marsh Creek at Vasco Rd. St-Sig D/D D/D D/D D/D 0.74/C 0.74/C For unsignalized intersections,each movement has its own level of service. The range of Level of Service results reflects all movements at the intersection. The critical level gencraUy occurs to the left turn movement from the side street. Mitigations are assumed for all intersections on Cypress Road. All other locations are calculated with no changes to existing conditions. Control conditions at intersections will change over time,traffic control designated as follows:N-No control,St-Stop signs,Sig- Traffic signal 3-49 Cumulative Traffic Forecasts (Year 2010) This scenario is assumed to approximate the land use and development conditions that will exist in the Year 2010. For this scenario, General Plan Amendment projects have been added to the travel model database. The traffic forecast data base is consistent with the cumulative traffic analysis included in the Contra Costa County General Plan. There are several new roadway projects that are included in the General Plan network. The proposed Delta Expressway would be completed, with interchanges at Laurel Road and Lone Tree Way. SR 4 would be widened and improved between Bailey Road and Highway 160. The Laurel Road extension would be completed to Cypress Road. Bethel Island Road would be extended to connect to Byron Highway. O'Hara Avenue would be extended south to Brentwood. Although the Delta Expressway is in the General Plan; construction would not be ' completed until Year 2005, and then only if adequate funding becomes available. Similarly, the SR 4 widening project between Bailey Road and Highway 160 would be a critical component of future cumulative improvements. Projected traffic forecasts will exceed the capacity of the i existing four-lane freeway by the Year 2000. This section of road will be significantly impacted by cumulative traffic. The resulting ADT and the estimated PM peak hour LOS that is forecast to occur under cumulative conditions is shown on Figure 3.2-11. With this level of development, traffic problems can generally be mitigated to an acceptable Level of Service by the improvements discussed above and listed in the General Plan. This EIR has utilized traffic forecast information from the Contra Costa County General Plan EIR. The cumulative land use assumptions in this EIR are a hybrid of the ABAG regional land use model, and the list of proposed projects that has been developed by Contra Costa County based on build-out of the General Plan. The traffic forecasts in the General Plan do not include traffic projections for the full build-out of the Cypress Corridor. The cumulative traffic forecasts have been based on the Year 2010 land use scenario. The 2010 land use data is based on General Plan build-out that has been adjusted to be consistent with ABAG regional forecasts. To make the adjustment between ABAG regional development assumptions and the County's list of reasonably forseable projects involved making the total land use conditions consistent with one another. Certain land use assumptions were reduced, while others have been deferred to occur beyond the year 2010 time period. The General Plan traffic model, therefore, does not include full build-out of the Cypress Corridor project. Since no specific Cypress Corridor project has been defined at this time, and the expected changes to the roadway network due to the Cypress Corridor have not been defined, the project at full build-out cannot be accurately modeled. However, the Cypress Corridor project will need additional roadway links into Oakley and could result in significant traffic congestion impacts if the only access were to be onto Cypress Road. 3-50 i. �V O N Q � Sand Mound Slough Rd v P=1 b C �. /CEMI;SIH uOIftg w w O O •'•''?i.. r.fv:: V a Ps PuEisI Iaipail ;;. ODWLi O--O------------ W -- .»»---L Owsi 4 x 0 tox in d� °d M bob © Ooh x M V and uasau$nrA E MOOLIV DAV 61ailaS v c Off. O .+ P^ifl PooMaualfl i� Ch U) PIN ,Qria c� @� d' a^V ME cl N OOVOT o� w DAV enHD 000`LZ °uP Q »TM Q AG P2Ialfl SFO and alFdulg t `tC4 61,000 01� , CD � .] �7i ►v, iV-i o 001, 3-51 1 Full build-out of the Cypress Corridor project is currently being tested as a part of the latest land use scenarios for the Delta Expressway EIR. This project is currently underway, and is scheduled to be completed in January, 1992. For the most up-to-date analysis of cumulative volumes, the Delta Expressway EIR should be used. The results of the Delta Expressway EIR analysis will affect the traffic projections on Cypress Road, SR 4, and other local roads in the Oakley area under the cumulative scenario. Planned Roadway Improvements The provision of an acceptable traffic system for this part of East County will require a large number of traffic improvements. The growth management provisions of the County General Plan call for construction of the necessary improvements by developers to mitigate traffic impacts of each development project. Regional Transportation Proiects - There are also a number of important regional transportation projects affecting East County which are currently in the planning stage. These projects are funded by Measure "C". They include the following: • SR 4: Willow Pass Grade Lowering - This project is currently being designed. Construction is scheduled to begin in July, 1992. • SR 4: Bailey Road-Final Design is underway, and construction is planned to start in 1993. • Corridor Study: SR 4 East - Project planning, traffic data forecasts have been completed. No financing plan nor construction schedule has yet been established. The roadway improvement projects described in Table 3.2-6. Many of these projects are needed in conjunction with the development of the Cypress Lakes Project and to mitigate Cypress Lakes project impacts. For each roadway project, it's description is provided along with an assessment of the time frame of when the project would be required. This first group of road projects`are those that would be required as a result of the Cypress Lakes project. The roadwayand intersection improvements identified in Table 3.2-6 would require P widening and acquisition of some adjacent property. However, the impacts of these road and intersection improvements would be minimal on adjacent properties. No residential or business displacement would occur as a result of these improvements. The intersection improvements at the project entrance and Cypress Road should be designed to.avoid impacting known cultural resources located to the south of existing Cypress Road near Bethel Island Road(see Section 3.12 for additional details). 3-52 Table 3.2-6 A) Projects That Would Be Required By Cypress Lakes Itself (without any other development taking place) �. 7 t IAD'WAY... .1)p'.RfJ'VEM)✓N......... ':P.RQJEC.:..::....... ....::.. OT..:::.::.....::.CgMMENTS ::::>:::;::::.....::..:..........:;.... TIM NG ::.:: ::::. .:::::::.:::.: 1) Construction of Cypress Rd./ When the first part Funded by Project Applicant Bethel Island Rd. intersection at of the Cypress the project entrance. Widening Lakes development to extend 1,000 feet in each is occupied. direction. 2) Construction of Cypress Rd. To be completed Funded by Project Applicant. from Machado Lane to 1,000 before 1,000 units The timing of this project, and feet east of Knightsen, are occupied. final design will be affected by including intersections at land use decisions and fSellers and Knightsen. development in the Cypress Corridor 3) Traffic signals at Sellers, To be installed Funded by Project Applicant. Knightsen, and Bethel Island when traffic The timing of these projects will Rd. (project entrance) volumes meet be affected by other Caltrans warrants. development in the Cypress Corridor and in the BIA. 4) Intersection improvements at Traffic signal to be Funded by Project Applicant. Sandmound Blvd. and Bethel installed when Timing of this improvement to Island Rd. volumes meet be affected by development on Caltrans warrants. Bethel Island.. In addition to the above, there are many other projects within the Bethel Island area that would be needed if the Bethel Island area is built-out under the County General Plan. These projects, however, are not needed as a direct result of the Cypress Lakes project. Many of these projects are not needed until more is known about the extent and timing of development on Bethel Island. Other projects relate to the planning and timing of the Lesher Landing project located to the west of Cypress Lakes. These road projects are listed below. 3-53 Table 3.2-6 (continued) B) Projects Necessary for the BIA Once Other Projects in the BIA Have Been Developed RQAD.WAY IMER.::VMENT:»>:> :>.......... .........:<:«<<«:>......: >>:><>i:>< ::<;:;:': €>;:>::>:€:€:>€::>:'>::<:>>«:>':! ::<:>>::<:><':::<:<::::>::::>=<::<:::::>::>:: 0...............................................:......................: :::.....................................,...::::..:::...:::................................:.::::::::::.::.::::::: :... ....:....:::.:... :..:. ..... ...:.; ::. :.::.:..::..:.. ::::::.;::;::;. .>:..... .:. :.;,..,;�;,,.:>.;:<:<.;.:<:;;><> '''>> '; `<'' THE ; `<::::,;.;:;;;::,;.;:;<;::>:.::<>:<.: > «< > <`« :I'17.O,IECTS::::::.;. ::::;:: :>:> :: .:::.: ..::: ::::::.::::::.:<::::.t'ROJEC....TIMWG:......... .... ..fl:.. :..R C4�VIMENTS..... .....::.:::: 1) Construction of Cypress Rd. from When the first part of the Funded by future development. Knightsen Ave. to Bethel Island Rd. Lesher Landing development This improvement would not be is occupied. needed until the initial stages of the Lesher Landing project are completed. 2) Construction of Bethel Island Rd. from When substantial Funded by future development. BI Bridge to Cypress Rd. development is completed on , Bethel Island. 3) Construction of Laurel Rd. This project would not be Funded by future development. Extension to Machado Lane, including needed until the Delta Marsh Creek Bridge and RR Expressway is completed. overcrossing. Until that time, this project would not be necessary. 4) Widening of Cypress Rd./SR 4 Necessary if Bethel Island Funded by future development. intersection. Construction of area is built- out before Delta The timing of this project would additional turn lanes. expressway is completed. also be affected by land use decisions and development in the Cypress Corridor. 5) Bethel Island Rd. extension to Rock Not needed until Prelli Funded by future development. Slough property is developed. To be completed before the Prelli property is occupied. 6) Bethel Island Bridge Not needed as a result of Funded by future development. Reconstruction Hotchkiss Tract development. The timing of this project would be affected by land use decisions and development on Bethel Island itself. In addition to the roadway improvements specified above, several roadway improvement projects are planned in the Oakley - North Brentwood area and would be very important projects that would be affected by the Cypress Lakes project. The following table lists these projects and discusses their general relevance to the Cypress Lakes project and future development in the Bethel Island area. 3-54 Table 3.2-6 (continued) Q Other Roadway Improvements that are a Part of the Oakley - North Brentwood Area Plan Ai:..: PRO E J i'ROJ1sCT TIMING OTHIE;R CbMMENTS ::.... ...... ..... Widening of SR 4 to six lanes between Not required but interim SR 160 and Empire Avenue. improvements would be required at the Neroly Rd intersection. SR 4 between Empire Avenue and Project underway, some Project is needed to accommodate downtown Brentwood; widen to four sections have been Cypress Lakes traffic. lanes completed. Lone Tree Way; widen to four lanes Not required by Cypress lakes project. Neroly Avenue between SR 4 and Not required by project. Interim improvements are required Oakley Road; widen to four lane at Neroly intersection Empire Avenue; widen to four lanes Not required by project. Laurel Avenue west of SR 4; widen to Not required by project. This project will be required by the four lanes project and other development in the BIA in conjunction with the Delta Expressway. O'Hara-Avenue; widen to four lanes Not required by project. Fairview Avenue; widen to four lanes Not required by project. Delta Expressway,a two-lane facility Not required by project. This project is required to between SR 160 and SR 4 southeast of accommodate the cumulative traffic Brentwood; forecasts - Year 2010 Laurel Road extension, a four- to Not required by project. six-lane facility between Neroly Avenue and Hillcrest Avenue; �. of require y project. Sunset Road extension; Not required by project. Rose Avenue extension; Not required by project. O'Hara Avenue extension; and of require y project. Lone Tree Way extension. 3-55 Phasing and Timing of Roadway Improvements As indicated in Table 3.2-6, all of the pieces are in place to provide a solid functioning roadway system for development in the Bethel Island area. However, the phasing plan beyond those improvements necessary for the Cypress Lakes project needs to be updated to reflect the current plans for each major development project, and the effects of the potential Cypress Corridor projects. There are several very important roadway projects that are not currently funded. These include the Delta Expressway project, and the Route 4 improvement from Bailey Road to Route 160. Without these projects, the cumulative land use and development plans for Oakley, North Brentwood, and the Bethel Island area cannot be accommodated without severe traffic and congestion problems. A more complete description of the effect of these future roadways is included in the Delta Expressway EIR, which is currently being completed by Contra Costa County. Construction Traffic Impacts The Cypress Lakes development is planned to be built out over afive-year period. Construction traffic would occur throughout this period, and would be fairly constant, with perhaps somewhat heavier traffic during the spring and summer periods. Construction traffic would consist of travel by employees and workers to the site, and truck delivery of heavy equipment and materials. Truck traffic could impact the pavement conditions on major access roads, especially Cypress Road. Truck traffic could affect road capacity during peak hours. It is estimated that at the time of the most intense construction activities, the traffic generated by the these activities would amount to about 1,200 to 1,500 vehicle trips per day, with about 70 to 90 vehicle trips during the commute peak hours. This amount of traffic would not cause a peak hour traffic impact. Truck traffic, however, may have a significant impact on freeway operations during peak periods. The major access road affected by construction truck traffic would be Cypress Road, which is scheduled to be widened and improved MITIGATION MEASURES Based on the traffic and circulation impacts identified in the previous section, a number of mitigation measures are recommended. These measures are intended to reduce the identified impacts to a less than significant level. The mitigation measures have been subdivided into the following categories: �1 1) Mitigation for traffic impacts where, as a result of the project,the peak hour Level of Service would decrease (worsen) to LOS "D" (V/C Ratio of 0.85) or worse. 2) Mitigations to help to reduce the amount of peak hour traffic generation from the project. 3-56 3) Mitigations to improve internal traffic circulation and parking, and to improve vehicle access to the project. 4) Mitigations to improve pedestrian and bicycle circulation. tMitigations of Vehicle Traffic Capacity Impacts Roadway and traffic mitigation measures have been defined.for each of the development r scenarios (existing and projected, 2000 and 2010). Most of the improvements that are necessary to accommodate the proposed project would be constructed by the project applicant. These roadway improvements would allow the roadways in the area to operate at an acceptable Level ■ of Service. For the scenario covering existing plus project traffic, the following improvements should be completed during the early stages of the project. These are shown on Figure 3.2-12. 3.2-1 Road Improvements at Project Entrance - Construct a new intersection at Cypress Road and Bethel Island Road, and on the approaches to this intersection. Widening should extend 1,000 feet in each direction. To properly accommodate the proposed project traffic as well as future traffic from other parts of the area, the intersection would have the lane requirements shown on the following Figure 3.2-13. The southbound approach would be widened with one more lane. This intersection should be designed so that it can ultimately be consistent with a future extension to Byron Highway south of the intersection. Cypress Road will cross the levee just east of the entrance to the project. The vertical curvature of Cypress Lakes Road where it crosses the levee needs further study. The final design of Cypress Lakes Road should be submitted prior to approval of the final subdivision map. A 45 mph design speed would be desirable. This project would include the installation of traffic signals that would be put into operation at the time that volumes meet Caltrans traffic warrants. This is estimated to occur when the project has about 500 units completed and occupied. Note: This improvement could impact Cultural Resources (see Section 3.12). (Responsibility: Project Applicant) 3.2-2 Bethel Island Road and Sandmound Boulevard - Bethel Island Road is planned to ultimately become a four-lane divided roadway between Cypress Road and the Bethel Island Bridge. This widening is not necessary as a result of the project, but there are interim improvements that should be accomplished. At Sandmound Boulevard, the intersection should be improved and widened, and left turn lanes I� should be constructed. Sandmound Boulevard should be realigned to a right-angle intersection at Bethel Island Road. This project would also include the installation of traffic signals that would be put into operation at the time that volumes meet Caltrans traffic warrants. This is not estimated to occur as a result of the project 3-57 O -Widen Cypress Road to Ultimate Cross-section OZ -Widen Cypress Road to Ultimate Cross-section OT -Traffic Signals to be Installed when Caltrans warrants are met , �v a . �v Methal Island IIslan s f ;r. 'Pa Gateway Rd Dutch Slough Rd :r 7• 1 0 Cypress Rd O Laurel Rd < ' V � d =J 1 ... L 1 y � � Knightsen Project Site Cypress Lakes EIIZ Figure 3.2-12 Roadway Improvements Traffic Impact Study Required by the Project Abrams Associates 12 CO G � N 7 N d W� 0 � E ` o i � a � d 3.59 itself, but would be needed as a result of development being completed on Bethel Island. Sandmound Boulevard should be improved along the eastern boundary of the project. (Responsibility: Project Applicant) of the implementation C ' 3.2-3 Cypress Road Widening - Complete the im p Cypress Road widening from Machado Lane to east of Knightsen Road. This roadway improvement should be in place before 1000 units are occupied at Cypress Lakes. It would include the installation of traffic signals at Sellers Road and Knightsen Road that would be put into operation at the time that volumes meet Caltrans traffic warrants. The widening of Cypress Road between Knightsen Avenue and Bethel Island Road should occur before occupancy of the Lesher Landing project or other project that adds over 25 units in this part of the Bethel Island area. (Responsibility: Project Applicant) 3.2-4 Sandmound Boulevard Improvements-This project would reconstruct Sandmound Boulevard from Bethel Island Road along the north border of the project. This project would be done in conjunction with other developments along Sandmound Boulevard. (Responsibility: Contra Costa County as a condition of future development) 3.2-5 Conformation with Measure C - The Cypress Lakes project would satisfy the requirements of Measure C by constructing the roadway improvements listed in Table 3.2-6 (A). The project may also be required to pay a regional traffic fee for Measure "C" projects. This fee has not been established, and is currently being evaluated by TRANSPLAN and the CCTA. The payment of these fees will help to mitigate the regional traffic impacts of this project. (Responsibility: Project Applicant) ' Mitigations to Reduce Peak Hour Trip Generation 3.2-6 Bus Transit Service - While there is no current transit in the area, it can be expected that daily bus transit service, provided by Tri-Delta Transit, would be provided to the Hotchkiss Tract and Bethel Island Area when a significant amount of the development in the area has been built and occupied. The situation should be monitored, and transit service should probably be started when about 1,000 homes have been completed in the area. This bus route could be an extension of Routes 383 and/or 384 and would follow Cypress Road and Bethel Island Road to a terminal stop on Bethel Island. (Responsibility: Tri-Delta Transit/Contra Costa County) There are no current plans for this transit route because the existing population distribution in this part of the County is not sufficient to justify the service. It is expected that , bus stops, and possibly bus bays, will be considered in the design plans for Cypress Road and 3-60 l: 1 Bethel Island Road. With the exception of these road improvements, the project applicant would not be responsible for contributing to this mitigation. 3.2-7 Participate in County TDM Program - The project would be required to comply with the County residential TDM Ordinance, the County Growth Management Program, and the Bay Area Air Quality District regulations regarding transportation. TDM requirements of the County include the preparation and distribution of a TDM information program that could include the provision of maps showing available transit routes, and information on ridesharing and vanpool services to prospective home buyers. These types of measures can be expected to have only a relatively small impact on reducing peak hour trips. Other studies have shown that TDM actions applied to a residential development can reduce the number of single occupant auto trips by 3-5 percent during the commute peak hours. (Responsibility: Project Applicant) Mitigations to Improve Internal Traffic Circulation ` The following mitigations are recommended to improve the internal circulation within the Cypress Lakes Project. 3.2-8 Design level plans for the project entrance on Sandmound Boulevard should be prepared and submitted to County Public Works Department for review and approval prior to approval of the first phased subdivision map. The design level plans should provide for: adequate transition from the levee cross-section to grade at Sandmound Boulevard; adequate stopping distance; and adequate corner sight distance. (Responsibility: Project Applicant) 3.2-9 Provide a right-of-way for a future roadway connection to the property south of Cypress Lakes. This property could develop into a residential neighborhood, and should desirably be connected into Cypress Lakes at some time in the future, especially for school trips and other internal recreational trips. However, such a roadway connection should not be the only access to this new area, and should be provided only after Bethel Island Road is extended south across Rock Slough. This road should be treated as a secondary connection, so that it would limit the amount of through traffic that would travel through the Cypress Lakes development. (Responsibility: Project Applicant) 3.2-10 Provide a road extension of Cypress Road through the project to connect to Sandmound Boulevard. Certain residents of Sandmound Boulevard area have protested this connection for the reason that they expect traffic from Cypress Lakes to impact their quiet residential streets. In practice, this should not occur. This connection would allow for more convenient access for existing residents, 3-61 providing a connection to the future school site, and easy access to Cypress Road through the project. (Responsibility: Project Applicant) Mitigations-to Improve Pedestrian and Bicycle Circulation. '. 3.2-11 Provide a major bicycle path within the project on Cypress Road between Bethel Island Road and Sandmound Boulevard, and on Cypress Lakes Drive through the project. This pathway should be designed to.County standards. (Responsibility: Project Applicant) 3.2-12 At such time as other roadway improvements are completed, complete other bicycle paths as required. This would include a pathway along Bethel Island Road on the west boundary of the project, a pathway along Rock Slough on the southern boundary of the project, a path along the Byron Highway Extension, and a pathway along Sandmound Boulevard on the north and east boundaries of the project. (Responsibility: Project Applicant/Contra Costa County as a condition on future development) Construction i Impact Mitigation Measures p g 3.2-13 Contra Costa County has standard restrictions on construction activities regarding hours of operation, noise and dust control. Additional mitigations could include restrictions on heavy trucks from SR 4 during the commute peak hours. The project could normally be required to assist in maintenance of roads that could be damaged by heavy trucks. Since the major access route, Cypress Road, would be partially reconstructed by the project, this type of project condition may not be necessary. (Responsibility: Project Applicant) Cumulative Impacts and Mitigation Measures As a result of the traffic generated by this project plus traffic from other cumulative development, there would be a number of significant traffic impacts if the identified roadway improvements are not completed in the proper timing, and in coordination with the pace of new development. Each of the various traffic impact studies of the area have generally established a schedule for roadway improvements that will avoid significant traffic impacts. As a requirement of Measure C and the Growth Management Element, new development will be required to satisfactorily mitigate traffic impacts. The following discussion describes mitigation for both short-term and long-term cumulative impacts. SHORT-TERM CUMULATIVE IMPACTS Traffic generated by Cypress Lakes will contribute to cumulative traffic, and the project will help to mitigate these impacts by paying the Subregional roadway fee. As a result of the roadway improvements identified in Table 3.2-6, most of the traffic impacts of the short-term 3-62 cumulative traffic growth can be mitigated to an insignificant level. However there are two exceptions where this may not be the case. The following mitigation measures should be addressed by the Cypress Lakes project if the Delta Expressway is not implemented, and if the problem is not mitigated by other sources. 3.2-14 Intersection of Neroly Road and SR 4 (Main St) -Widen the northbound approach to provide a double left turn from Neroly Road to SR 4. This will improve the V/C ratio from 0.93 ("E") to 0.81 ("D"). This will reduce this impact to a less than significant level. The project traffic will amount to about 10 percent of the traffic growth that is projected at this location. The applicant should be required to pay a fair share fee equal to about 10 % of the cost of this improvement. (Responsibility: Project Applicant) 3.2-15 . Intersection of Cypress Road and SR 4 - Widen the southbound approach to provide a double left turn lane for traffic from SR 4 to Cypress Road, and widen Cypress Road on the east leg of the intersection. This will improve the V/C ratio from 0.87 ("E") to 0.79 ("C"), and will reduce this impact to a less than significant level. The need for this improvement will depend entirely on the pace of development and the timing of the construction of the Delta Expressway. If the Cypress Corridor development moves quickly to implementation, prior to the completion of the Delta Expressway, this mitigation will be required. The need for this improvement will be reduced if the Laurel extension is completed, and the Laurel Avenue connection to the Delta Expressway is completed. Traffic from the Cypress Lakes project will amount to about 25 percent of the traffic growth that is projected at this location. The applicant should be required to pay a fair share fee equal to about 25% of the cost of this improvement. (Responsibility: Project Applicant) LONG-TERM CUMULATIVE IMPACTS 3.2-16 Traffic generated by the Cypress Lakes project will contribute to long-term cumulative traffic. In particular, the Cypress Lakes Project will have a cumulative impact on SR 4 in the freeway section between Bailey Road and Highway 160, and on the arterial section between Highway 160 and Cypress Road. The Cypress Lakes project will assist in mitigating these impacts by paying the subregional road fee. As a result, most of the traffic impacts of the long-term cumulative traffic appear to be mitigated to an insignificant level. (Responsibility: -Project Applicant) There are several major projects,however,where adequate financing is yet to be resolved, and which will be needed by 2005. These include the improvement of SR 4 from Bailey Road to SR 160, and the Delta Expressway. Based on the latest financing data presented by the OCTA,these projects have a funding shortfall of,up to 500 million dollars. Contra Costa County, through the CCTA and the East County Transportation Planning Committee, is currently evaluating funding options, and is planning for the implementation of these projects. 3-63 3.3 AIR QUALITY The following air quality analysis of the project was prepared by Don Ballanti, certified consulting meteorologist. �. EXISTING SETTING Air Ouality Standards The Federal Clean Air Act of 1970 and State Mulford-Carrell Act of 1967 established air quality standards for several pollutants. The federal standards have two tiers: primary standards designed to protect the public health and secondary standards intended to protect the public welfare from effects such as visibility reduction, soiling, nuisance and other forms of damage. The state and federal ambient air quality standards are shown in Table 3.3-1. Pollutant Characteristics The project is within the Bay Area Air Basin. Within this air basin, the state and federal air quality standards for nitrogen dioxide, sulfur dioxide and lead are met. Standards for other pollutants such as ozone, carbon monoxide and suspended particulate (PM-10) are not met in at least a portion of the air basin. A discussion of the characteristics, major sources and health effects of these pollutants follows. OZONE Ozone is the most prevalent of a class of photochemical oxidants formed in the urban atmosphere. The creation of ozone is a result of complex chemical reactions between hydrocarbons and oxides of nitrogen in the presence of sunshine. Unlike other pollutants, ozone is not released directly into the atmosphere from any sources. The major sources of oxides of nitrogen and reactive hydrocarbons, known as ozone precursors, are combustion sources such as factories and automobiles, and evaporation of solvents and fuels. The health effects of ozone are eye irritation and damage to lung tissues. Ozone also damages some materials such as rubber, and may damage plants and crops. CARBON MONOXIDE that is highly toxic. It is formed b the Carbon monoxide is an odorless, colorless gas t g y y incomplete combustion of fuels, and its main source in the Bay Area is automobiles. Carbon monoxide's health effects are related to its affinity for hemoglobin in the blood. At high concentrations, carbon monoxide reduces the amount of oxygen in the blood, causing heart difficulties in people with chronic diseases, reduced lung capacity and impaired mental abilities. 3-64 Table 3.3-1 FEDERAL AND STATE AMBIENT AIR QUALITY STANDARDS Federal ede al Averaging Primary State Pollutant Time Standard Standard Ozone 1-hour 0.12 ppm 0.09 ppm Carbon Monoxide 8-hour 9.0 ppm 9.0 ppm 1-hour 35.0 ppm 20.0 ppm Nitrogen Dioxide annual 0.05 ppm -- 1-hour -- 0.25 ppm Sulfur Dioxide annual 0.03 ppm -- �, 24-hour 0.14 ppm 0.25 ppm 1-hour -- 0.5 ppm PM-10 annual 50.0 pg/m3 30.0 pg/m3 24-hour 150.0 pg/m3 50.0 pg/m3 Lead 30-day avg. -- 1.5 pg/m3 3-month avg. 1.5 pg/m3 -- a Federal primary standards are designed to protect public health. The secondary standards are to protect the public welfare from other effects such as soiling and visibility reduction. b The state PM-10 standard is for theg eometric mean of all measurements. The federal standard is based upon the arithmetic mean of all measurements. Notes: ppm = Parts per million -- = Not applicable pg/m3 = Micrograms per cubic meter 3-65 SUSPENDED PARTICULATES (PM-10) Suspended particulate matter consists of solid and liquid particles of dust, soot, aerosols and other matter which are small enough to remain suspended in the air for a long period of time. A portion of the suspended particulate matter in the air is due to natural sources such as wind blown dust and pollen. Man-made sources include combustion, automobiles, field burning, factories and unpaved roads. A portion of the particulate matter in urban atmospheres is also a result of photochemical processes. The effects of high concentrations on humans include aggravation of chronic disease and heart/lung disease symptoms. Non-health effects include reduced visibility and soiling of surfaces. '- Sensitive Receptors The Bay Area Air Quality Management District defines sensitive receptors as those facilities most likely to be used by the elderly, children, infirm, or persons with particular sensitivity to air pollutants. Examples are hospitals, schools and convalescent homes. There is one convalescent home located near the project site along Sandmound Boulevard. There are several residences located along roads accessing the site and near the periphery of the site on the north and east side. In addition, many of the area residents are elderly and may be particularly sensitive to air pollutants. Current Air Quality The project site is on the eastern edge of the nine-county Bay Area Air Basin. The Bay Area Air Quality Management District operates a network of air quality monitoring sites throughout the air basin. A monitoring station is located on adjacent Bethel Island. A summary of air quality data from the Bethel Island monitoring site is shown in Table 3.3-2. Data is shown for the years 1988-1991. Table 3.3-2 shows that the federal ambient air quality standards for most criteria pollutants -10 measured at the Bethel Island site has, however, are met. Concentrations of ozone and PM _ exceeded the more stringent State standards on occasion. Re Tonal Air ualit Plannin � v � The San Francisco Bay Area has been designated as a region where three national ambient air quality standards are being exceeded. Under the 1977 Clean Air Act, the Association of Bay Area Governments (ABAG) was empowered to prepare a non-attainment plan for ozone, carbon monoxide and suspended particulates. The Clean Air Act Amendments of 1977 specified that the national ambient air quality standards were to be met by 1982, with provision for extension of the deadline five years to 1987. However, the national ambient air quality standards were not met'in the Bay Area by the end of 1987. 3-66 Table 3.3-2 AIR QUALITY DATA FOR BETHEL ISLAND, 1988-1991 Pollutant Standard Year Days Exceeding Ambient Standards at Bethel Island Ozone Fed. 1-Hour 1988 0 1989 0 1990 0 1991 0 Ozone State 1-Hour 1988 7 1989 11 1990 5 1991 3 Carbon Fed. 8-Hour 1988 0 Monoxide 1989 0 1990 0 1991 0 Nitrogen State 1-Hour 1988 0 Dioxide 1989 0 1990 0 1991 0 Sulfur Fed. 24-Hour 1988 0 Dioxide 1989 0 1990 0 1991 0 PM-10 State 24-Hour 1988 10 1989 7 1990 7 1991 10 --------------------------- Sources: California Air Resources Board, California Air Quality Data, Annual Summary,Vols. XIX-XXII, �. 1988-1991. Bay Area Air Quality Management District, Air Currents, March 1992. i 3-67 The Clean Air Act Amendments of 1990 require that non-attainment areas develop plans and strategies that will reduce pollutants by 15% during the first 6 years, then 3% annually thereafter until the standards are met. Areas must meet the standards within 5 to 17 years, depending on the severity of the problem. , The California Clean Air Act,enacted in 1989,requires local air pollution control districts to prepare air quality attainment plans for ozone and carbon monoxide. Generally, these plans must provide for district-wide emission reductions of five percent per year averaged over consecutive three-year periods. The Act also grants air districts explicit statutory authority to adopt indirect source regulations and transportation control measures, including measures to encourage or require the use of ride sharing, flexible work hours or other measures which reduce the number or length of vehicle trips. orf According to the Bay Area Quality Management District, Bay Area '91 Clean Air Plan (CAP), Volume 1, October 1991, the area-wide plan required by the California Clean Air Act has recently been adopted. . The Plan proposes the imposition of controls on stationary sources (factories, power plants, industrial sources, etc.) and Transportation Control Measures designed to reduce emissions from automobiles. The Bay Area '91 Clean Air Plan forecasts continued improvement in regional air quality. An analysis of carbon monoxide trends in the Bay Area shows attainment of the standards throughout the air basin by the mid-1990s. However, implementation of the Plan would not provide for attainment of the State ozone standard even by the year 2000. Standards of Si nificance Appendix G of the CEQA Guidelines establishes that a project will normally have a significant impact on air quality if it will "violate any air quality standard, contribute substantially to an existing or projected air quality violation, or expose sensitive receptors to substantial pollutant concentrations". For the purposes of this study a significant impact on local air quality is defined as an increase in carbon monoxide concentration causing exceedance of the state or federal standards. For regional air quality a significant impact is defined as an increase in emissions of an ozone precursor, sulfur dioxide or PM-10 which would exceed the Bay Area Air Quality Management District's recommended thresholds of significance. According to the Bay Area Air Quality Management District, Air Quality and Urban Development Guidelines, 1985 (Revised 1991), the District considers increases in emissions of regional pollutant of 150 pounds per day to represent a significant adverse impact. ' 3-68 , a IMPACTS Construction Impacts Construction activities are a source of g organic as emissions. Solvents in adhesives, non- g waterbase paints,thinners, some insulating materials and caulking materials would evaporate into �! the atmosphere and would participate in the photochemical reaction that creates urban ozone. Asphalt used in paving is also a source of organic gases for a short time after its application. Construction equipment would be a source of exhaust emissions during periods of construction activity. Table 3.3-3 shows emission factors for various pollutants for typical diesel powered construction equipment. The actual exhaust emission from construction on any given day would depend on the number, type and hours of operation of for each equipment type. The major construction period air quality impact of the proposed project would be dust generated by equipment and vehicles. Fugitive dust is emitted both during construction activity and as a result of wind erosion over exposed earth surfaces. Clearing and grading activities comprise the major source of construction dust emissions, but traffic and general disturbance of the soil also generate significant dust emissions. Construction dust impacts are extremely variable, being dependent on.wind speed, soil type, soil moisture,the type of construction activity and acreage affected by construction activity. The very fine, silty soils of the site and the strong and persistent winds typical of the area combine to create a high potential for wind erosion of soils. The highest potential for '�- construction dust impacts would occur during the dry late spring, summer and early fall months when soils are dry. Earthmoving and grading operations are likely to be the operations generating the bulk of dust emissions. A rough estimate of uncontrolled construction PM-10 emissions is 0.6 tons per month per acre of active construction. Assuming that the average period of active construction on the 685.9-acre site is 3 months at any one location, the resulting total emission of PM-10 over the course of build-out would be about 785 tons if dust control measures are not implemented. The effects of construction activities would be increased dust fall and locally elevated tlevels of PM-10 downwind of construction activity. During the construction period the potential for dust nuisance would exist at homes along Sandmound Boulevard which are downwind of the project site. Construction-related air quality impacts are considered to be potentially significant unavoidable impact on a localized basis. To help reduce dust emissions during construction of the proposed project, the project plans include the following dust control measures: 3-69 • The name and phone number of a designated dust control coordinator will be posted at the construction site. The dust control coordinator will respond to complaints by suspending dust-producing activities or providing additional personnel or equipment for dust control. • The contractor will implement the following measures: 1. Suspend earthmoving or other dust-producing activities during periods of high winds; 2. Provide equipment and personnel as necessary for watering of all exposed or disturbed soil surfaces. An appropriate dust suppressant, added to water before ` application, should be utilized; 3. Water or cover stockpiles of debris, soil, sand or other materials that can be blown by the wind; , 4. Sweep adjacent streets of all mud and debris, since this material can be pulverized and later resuspended by vehicle traffic; 5. Water, seed, cover or apply dust suppressants to completed cuts or graded areas as soon as grading activities cease. Effects on Carbon Monoxide Concentrations On the local scale, the project would change traffic on the local street network, changing �t carbon monoxide levels along roadways used by project traffic. Carbon monoxide is an odorless, colorless poisonous gas whose primary source in the Bay Area is automobiles. Concentrations of this gas are highest near intersections of major roads. The CALINE-4 computer simulation model was applied to four intersections and three curbside locations near the project site. These locations were selected as being near the heaviest concentrations of auto traffic, which should provide an estimate of the maximum carbon monoxide concentrations occurring near the project site. The model results were used to predict the maximum 1-and 8-hour concentrations, corresponding to the 1- and 8-hour averaging times specified in the state and federal ambient air quality standards for carbon monoxide. The CALINE-4 model out puts and the assumptions made in its use for this project are described in Appendix C. Tables 3.3-4 and 3.3-5 show the results of the CALINE-4 analysis for the peak 1-hour and 8-hour traffic periods in parts per million (PPM). The analysis was carried out for existing traffic conditions, with the addition of project traffic and under cumulative traffic conditions in the year 2005, based on the traffic analysis prepared by Abrams & Associates (see Chapter 3.2). r� . 3-70 Table 3.3-3 EMISSION RATES FOR DIESEL-POWERED CONSTRUCTION EQUIPMENT �• Equipment Type Emission Rate (pounds/hour) for. TOG CO NOx PM-10 SOx Scraper 0.3 1.0 3.8 0.4 0.5 Motor Grader 0.1 0.2 0.7 0.1 0.1 Off-Highway Truck 0.2 1.8 4.2 0.3 0.5 Roller 0.1 '0.3 0.1 0.1 0.1 -------------------------------------- TOG =Total Organic Gases CO= Carbon Monoxide NOx = Nitrogen Oxides PM-10=Particulate Matter, 10 micron SOx = Sulfur Oxides ----------------------------------- U.S.Environmental Protection Agency,Compilation of Air Pollutant Emission Factors,Volume 11: Mobile Sources, AP-42, Fourth Edition, 1985. rThe 1-hour values are to be compared to the federal 1-hour standard of 35 PPM and the state standard of 20 PPM. The 8-hour values in Tables 3.3-4 and 3.3-5 are to be compared to the state and federal standard of 9 PPM. 4 The CALINE 4 analysis evaluated four intersection locations and three curbside locations. The receptor location was established at 8 meters (25 feet), from the edge of the roadway or intersection. This distance represents the location where a residential or commercial use may result in a continuous 1-hour or 8-hour exposure. Existing concentrations at the four intersections and three curbside locations are well below applicable state and federal 1-hour and 8-hour standards. The addition of project traffic would increase concentrations, but they would remain below the most stringent state or federal standards. Carbon monoxide concentrations would decrease in the future, despite increased traffic, due to increasingly stringent emission controls on vehicles. Although development of the proposed project would increase traffic on the local street network, it would not substantially increase carbon monoxide concentrations along local streets and would not result in violations of the carbon monoxide air quality standards. 3-71 Table 3.3-4 WORST CASE INTERSECTION CARBON MONOXIDE CONCENTRATIONS, IN PPM Intersection Case 1 Case 2 Case 3 1-Hr 8-Hr 1-Hr 8-Hr 1-Hr 8-11r BethelIsland/Sandmound 4.6 3.2 5.4 3.2 3.7 2.6 BethelIsland/Cypress --- --- 7.0 4.9 4.8 3.2 BethelIsland/Gateway 4.0 2.8 4.2 2.9 4.0 2.5 Cypress/SR 4 7.5 5.2 10.3 7.2 4.7 3.3 Most Stringent Standard 20.0 9.0 20.0 9.0 20.0 9.0 --------------------------------- Case 1 = Existing (1992) Case 2= Existing+ Project (1992) Case 3 = Cumulative (2005) Table 3.3-5 WORST CASE CURBSIDE CARBON MONOXIDE CONCENTRATIONS, IN PPM Location Case 1 Case 2 Case 3 1-Hr 8-Hr 1-Hr 8-Hr 1-Hr 8-Hr Sandmound East of Bethel Island 2.7 1.9 3.4 2.4 2.2 1.5 Bethel Island Between Sandmound 4.7 3.3 5.2 3.6 4.1 2.8 and Cypress Cypress Between Bethel Island 4.7 3.3 8.4 5.9 4.9 3.4 and Jersey Island Most Stringent Standard 20.0 9.0 20.0 9.0 20.0 9.0 ------------------------------- Case 1 =Existing (1992) Case 2 = Existing+ Project (1992) Case 3 = Cumulative (2005) 3-72 Table 3.3-6 PROJECT-RELATED REGIONAL EMISSIONS, IN POUNDS PER DAY �. Pollutant ROG NOx PM-10 sox Auto Emissions 238.3 383.5 39.6 45.6 Residential Emissions 151.8 30.2 10.5 1.8 Total Emissions 390.1 413.7 50.1 47A BAAQMD Threshold 150.0 150.0 150.0 150.0 ROG = Reactive Organic Gases NOx = Nitrogen Oxides PM-10=Particulate Matter,Ten Microns -' SOx = Sulfur Oxides No sensitive receptors would be adversely affected. Therefore, the project's impact on local carbon monoxide levels is considered to be less-than-significant. r� Effects on Regional Air Ouality The project would be an indirect source of regional emissions, in that it would generate vehicle trips. Trips to and from the project would result in air pollutant emissions affecting the entire San Francisco Bay air basin. To evaluate the emissions associated with the project the URBEMIS-3 computer program, developed by the California Air Resources Board, was utilized. The URBEMIS-3 program and the assumptions made in its uses are described in Appendix B. Project-related automobile emissions are shown in Table 3.3-6. In addition to being an indirect source,residential development can be considered an area source in that it contains a number of dispersed and intermittent sources of pollutants such as space and water heaters, household paints and solvents,fireplaces and wood stoves, lawn mowers and other equipment. The annual emission factors from the Bay Area Air Quality Management District, Air Ouality and Urban Development Guidelines, 1985, were applied to the project to � estimate emissions from this source. Residential emissions are shown in Table 3.3-6. The daily increase in regional emissions associated with the project is shown in Table 3.3- r6 for Reactive Organic Gases and Oxides of Nitrogen (two precursors of ozone), Sulfur Dioxide and PM-10. Guidelines for the evaluation of project impacts issued b the Ba Area Air Quality P J P Y Y Management District consider emission increases for regional pollutants to be significant if they 3-73 exceed 150 lbs per day. Project emissions shown in Table 3.3-6 would exceed the criterion for two of the four pollutants (ROG and NOx), therefore, the project would result in a significant adverse impact on regional emissions. The Bay Area continues to experience growth in population and vehicle use that will affect the emission of regional pollutants such as Reactive Organic Gases and.Nitrogen Oxides. Current projections are that regional emissions of these pollutants will decrease in the future, despite cumulative growth in population and vehicle use, due to regional programs for reducing emissions that are in place or currently being considered. Continued improvement in regional air quality is projected through the year 2000, although attainment of all air quality standards throughout the entire Bay Area Air Basin is not protected by the year 2000. (Bay Area Air Quality Management District, Bay Area '91 Clean Air Plan (CAP), October, 1991.) MITIGATION MEASURES Construction Construction impacts have been identified as potentially significant on a local basis. While construction impacts are generally considered short term, the relatively long construction period for the project (10-years) would contribute to the significance of these impacts. However, the severity of construction impacts will be reduced through implementation of the dust reduction measures proposed as part of the project plans. To ensure dust emissions are kept to a minimum during construction, the following mitigation measures should be applied: 3.3-1 The dust control measures proposed as part of the project plans should be made conditions of the project approval. (Responsibility: Contra Costa County) 3.3-2 In addition to the dust control measure proposed by the project, All construction vehicles should be limited to 15 miles per hour while on the project site. The 15 mph limit should be posted on the site at all times during construction. (Responsibility: Project Applicant) Implementation of the above mitigation measure will reduce construction period dust t emissions, however; the potential for dust nuisance would still remain at times along Sandmound Boulevard. Therefore, dust emissions during construction would be considered a potentially significant unavoidable localized impact. Mitigation For Project Related Regional Emissions r The following mitigation measures are proposed to reduce project related regional emissions by reducing traffic volumes generated by the project in compliance with the County's Transportation Demand Management Program for residential uses. 3-74 ' 3.3-3 Comply with the County's Transportation Demand Management Program Ordinances 92-31 by preparing and providing TDM information to prospective home buyers. The TDM information should contain materials describing transit, ride sharing and van pool services. (Responsibility: Project Applicant) 3.3-4 The project should provide for transit stops along Cypress Road within the project site, along Cypress Lakes Drive, Sandmound Boulevard and Country Club Drive. (Responsibility: Project Applicant) 3.3-5 The proposed project design includes pedestrian/bicycle paths linking recreational and residential uses within the site (see Section 3.9). In addition to these facilities, bicycle parking areas should be provided at all recreational facilities within the project site (Golf Course Clubhouse, Beach Club and Public Ballpark). (Responsibility: Project Applicant) The combined effect of the above mitigation measures to reduce daily trips is difficult to quantify. Due to the relative remoteness of the site, the above mitigation measures would be expected to result in a maximum trip reduction of 10% with air quality impacts associated with auto use being reduced proportionally. However, even with reductions of this magnitude the incremental impact of the proposed project on regional air quality (ROG and NOx) would remain significant and unavoidable. L 3-75 i - 3.4 VEGETATION AND WILDLIFE ' EXISTING SETTING Existinji Vegetation and Wildlife Habitats The following information regarding existing vegetation and wildlife habitats located on the project site is summarized from the Special-Status Species Survey, October 1991, which was prepared by Huffman & Associates, Inc. Field surveys were conducted in May and September 1991. The Special-Status Species Survey was prepared to determine whether any sensitive, threatened or endangered (special-status) plants or animals inhabit the project site. The survey methods included a literature review of prior field surveys included in the Contra Costa County General Plan (1991), the BIASP (1991), the Department of Fish and Game's Natural Diversity Data Base, the California Native Plant Society's Inventory (1988), and the U.S. Fish and Wildlife Service's list of candidate and federally listed plants and animals. A list of taxa potentially occurring in the study area was compiled based on the background literature reviewed (see Table 3.4-1). A vegetation map of the project site was prepared based on soil associations, unique and dominant plant species and existing land uses (see Figure 3.4-1). Field surveys of the project site were conducted on May 20, 24 and September 4, 1991 to search for special-status plants, map vegetation and characterize wildlife habitats for the potential support special-status animals. Observations of wildlife were also recorded during the field surveys. A list of plant species observed during the field surveys was compiled and is contained in Appendix C. The vegetation and wildlife habitats present on the project site can be broken into nine (9) separate units: 1) developed/residential; 2) non-native annual grassland; 3) non-native annual grassland/interior stabilized dune; 4) annual croplands; 5) irrigated pasture and hayfields; 6) salt- affected meadows and scalds; 7) irrigation and drainage ditches; 8) willow scrub riparian; and 9) wetland habitat. The location and existing characteristics of each of these vegetation and wildlife habitats is described in the following discussion. Developed/Residential This habitat type accounts for approximately 10 acres of the project site and includes homes, farm shops and equipment storage areas, barns and unvegetated paddocks. I Non-Native Annual Grasslands This habitat type accounts for approximately 170 acres of the project site. These areas are generally grazed by cattle during the winter and spring and left fallow in the dry summer 3-76 1 dm DO 0. 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II ,' �1't4 •' L, �1 1111 11 ,1 1111 i 1 ,..�:_� , , 111,,,1 !'s � F: • f11,111 t.= • ( 1 ,r r ♦ yt �.; ... �^'�� • i•I �.� j ". .. t':• _..1�•'-�:Tr: ., a � %iJt '{, %UARCWI AT CIWLHADI :..• +`+,1414 'F •. -NATIVE ANNUAL iWw '�;"' "V";T� • G}IASSLAND A>} 1:,*e*18..":.fr!"•+ � + ::.. ►"ti1:� . t fs 4f •t,1�, :1 .1 .u{, �� ,y,s.rr ..�.. ,;�� 'ice:-� .,�'•� ��':. S •,�'.it '�a�' •,•�,"C' r N,1�...� �tia+• �r"_':.I �i•,�• 11T /•S'> •;-`'` .• •���" 4 y .l1 j,'rFT -t•�i�11J^'J, .:O: •,a�"`F 1 Figure 3.4-1: CYPRESS LAKES & Vegetation and Habitat Map COUNTRY CLUB PROJECT - Source: Huffman and Associates 3-78 months. Some areas are largely barren of vegetation where cattle congregate for supplemental feeding. The dominant vegetation includes ripgut brome Bromus diandrus), barley ordeum ' le orium , russian thistle Salsola kali and saltgrass. Most of the annual grasslands are growing on sandy substrate. The southwestern segment of the project site contains Sacramento clay soil which may be appropriate habitat for caper- fruited tropidocarpum (Trovidocarpum capparideum). However, this plant was not observed during the field surveys. Cattle grazing and other land use activities probably do not favor the ' presences of this species. The plant currently has no known populations and may no longer exist in the wild. t During the field surveys black-tailed jackrabbit a us californicus), California ground squirrel (Syerrmophilus beeche i , red fox ul es , and burrowing owls S eot to cunicularia) were observed in the annual grassland. Previous reports of black-shouldered kite lanus caeruleus foraging within the Bethel Island planning area could have been made on the project site. The grassland and irrigated pasture could support prey species for kites as well as short- eared owl Asio flammeus , golden eagle (Aguila chrvsaetos), and prairie falcon (Falco ' mexicanus). The intensity of grazing and other activities on the project site probably limits nesting sites for short-eared owls but it is possible that owls forage on the property in the late fall and winter. Golden eagles and prairie falcons are observed in the delta region during late ' fall and winter foraging in agricultural fields. It is possible that these species may use the property as winter foraging ground. The northern brown skink Eumeces ilberti placerencis) which uses a variety of habitats including grasslands, is included in Contra Costa County's list of important animals but is not currently considered a species of special concern by the Department of Fish and Game. The ' northern brown skink was not observed during the field surveys. Non-Native Annual Grassland/Interior Stabilized Dunes ' This habitat type is found on high sandy hills which in the historic delta landscape were ' above the tidal action and supported a mosaic of active dune and shrub-dominated upland plant community. This habitat type has declined in the delta region due to agricultural and urban expansion. Within the project site, the dune habitat has been significantly degraded to the point where the dunes support a continuation of the annual grassland with a few characteristic herbs such as gilia Gilia capitata and Croton Croton califomica) and shrub lupine Lu inus albifrons which set the areas apart from the rest of the non-native grassland. Remnants of.the interior dune habitat account for approximately_12 acres of the project site. Neither the Antioch Dunes wallflower Ervsimum cavitatum var. angustifolium) nor Antioch evening primrose Oenothera deltoides ssp. howellii which .are special status plants associated with this habitat type were present during the field surveys. ' 3-79 1 The interior dune habitat may provide habitat for the California legless lizard Anniella ' ulcra , California black legless lizard Anniella Pulcra nigra and the Coast horned lizard (Phyrynosoma coronatum) which are animals of special concern. However, none of these animals was observed during the field surveys. ' Several special-status insects-are known to be associated with the interior stabilized dune ' habitat. Three of these species once thought to inhabit the Antioch dunes are no longer thought to exist there due to rapid growth in the area. These species include the Antioch Dunes anthicid Anthicus antiochensis), the San Joaquin dune beetle Coelis gracilis and the shieldback katydid Neduba extincta . Other special-status species which are known to be associated with interior ' stabilized dune habitat and could be present on the project site include the Antioch sphecid wasp (Philanthus nasalis , Antioch multillid ant-wasp (Myrmosula pacifica , the yellow-banded ' andrenid bee Perdita hirticeps luteocincta), sphecid wasps ucerceris rufice s , Antioch cophuran robberfly Co Kura hurdi , Antioch efferian robberfly Efferia antiochi , and the. Sacramento anticid Anthicus sacramento). However, based on habitat dissimilarities, land use ' and degree of disturbance in the dune soils present on the project site, the probability that these insects occur on the project site is low. Annual Croplands This habitat type accounts for approximately 115 acres of the project site. These areas were cultivated and left fallow for the summer before the field surveys. The vegetative character ' of this habitat is predominately weedy including bindweed (Convolvulus arvensis , common sunflower (Helianthus annus), heliotrope (Heliotropium currasavicum), and bermuda grass ' (Cynodon dart lon . During the winter and spring the annual cropland habitat may provide foraging ground ' for small mammals and birds of prey as discussed above under annual grassland. Irrigated Pasture and Hayfields ' This habitat type accounts for approximately 275 acres of the project site. These areas are used for cattle and horse grazing and are periodically cut for hay. The irrigated pastures have ' been planted with bird's foot trefoil Lotus corniculatus), tall fesuce Festuca arundinacea) and creeping rye 1 mus triticoides . A small portion of the vegetative cover consisted of saltgrass Distichlis s icata and curly dock Rumex cris us . Because cattle were removed from several ' of the pastures a dense growth of yellow star thistle Centaurea solstitialis and cocklebur Xanthium strumarium) was present. No special-status plants were observed in the irrigated ' pastureland. Animals typically present in this habitat type include rodents and-seed eating birds. The ' Grasshopper sparrow (Ammodramus savannarum ssp. perpallidus) is a species included on the County's list of special animals which utilizes pastures and grassland similar to that present on the project site. However, the project site is located beyond the eastern edge of the species' , 3-80 _ t ' known range and therefore, the probability of finding the sparrow on the project site is considered low. ' Salt-Affected Meadows and Scalds This habitat type accounts for approximately 40 acres of the project site. Vegetation ' associated with this habitat is tolerant of highly saline or alkaline soils in low lying areas which were tidally inundated and supported marshes prior to construction of the levees. Most of the ' salt-affected areas have less vegetative cover than surrounding grasslands. The dominant vegetation includes five-horned smotherweed Bassia hyssopifolia), henfat (Atriplex patula , pickleweed Salicornia vir inica , alkali heath Frankenia grandifolia), and whitetop Le idium katifolium). Approximately 4.12 acres of this habitat has a sufficient duration of near-surface water to qualify as wetlands. Some of the seasonal wetlands in this alkaline habitat support foxtail barley Hordeum 'ubatum , purple sand spurry (Spergularia rubra) and brassbuttons Cotula coronopifolia). One plant species of special concern, the saltmarsh bird's beak ' (Cordylanthus mollis ssp. mollis , could occur around the borders of the salt-affected wetlands on the project site. However, this plant was not found during the field surveys. Valley sacaton grassland is a natural community on alkaline soil that is.declining in the state and is tracked by the Department of Fish and Game's Natural Diversity Data Base. The ' salt-affected or alkaline meadows on the project site are not good representatives of valley sacaton grassland. The dominant plants are weedy species tolerant of grazing rather than native flora. ' The northern salt marsh harvest mouse (Reithrodontomys raviventris haliocoetes) is the special-status animal most likely to occur in salt-affected habitats. However, the vegetation ' present on the project site is not characteristic of the typical habitat for the northern salt marsh harvest mouse. In addition, the seasonal wetlands present on the project site are not extensive nor are they adjacent to higher quality tidal habitats. The eastern most known population of the ' salt marsh harvest mouse is 17 miles west of the project site (C.N.D.D.B. Element Occurrence Records). ' Irrigation and Drainage Ditches ' Irrigation and drainage ditches account for approximately 38,000 linear feet of the project site. The ditch system consists of a main drain which runs from west to east across the northern portion of the project site. Several connecting ditches carry water to individual pastures or drain ' the annual cropland. The main drain is considered a regulated water and the secondary ditches are not considered a regulated water or wetland. ' Vegetation in the ditches is dense but discontinuous consisting of cattail (Typha larifolia , bulrush Scrius californicus), nettle Urtica urens , poison hemlock Conium maculatum), soft .rush Juncus effusis , and giant reed (Phragmites australis . Special-status plants in eastern ' Contra Costa County which may be associated with the drainage ditch habitat include Suisun 3-81 1 aster Aster chilensis var. lentus , Bolander's water hemlock Cicuta maculata var. bolanderi , ' Suisun thistle Cirsium hydrophyllum var. hydrophylum), Marsh gum plant Grindelia humilis), California hibiscus Hibiscus californicus), Delta tule pea Lath s 'e sonii ssp. 'e sonii , Mason's lilaeopsis Lilaeo sis masonii and slough thistle Cirsium crassecaule). However, none ' of these plants were observed during the field surveys. The drainage and irrigation ditches on the project site support the greatest number and ' diversity of wildlife species of the habitats present. Waterfowl observed in the ditches include cinnamon teal Anus cyarioptera), and mallards Anus platyrhynchos). Red-winged blackbirds A elaius phoeniceus) were observed nesting in the dense brush while ring-necked pheasants ' Phasianus colchicus used the dense vegetation along the ditches for cover. Northern harrier Circus c annus was observed foraging along the main drain. Other animals observed include ' coyote (Canus latrans , red fox, black-tailed weasel Mustela frenata , and California ground squirrels. Tracks of raccoon (Procyon lotor , skunk (Mephitis sp.) and opossum (Didelphis virginiana) were observed in dried, ditch bottom mud. Aquatic animals such as crawfish (Pacifastacus sp.), pond turtles Clemm s marmota , bullfrogs Rana catesbeniana) and minnows ' were also found in the main drain where water is present throughout the year. Animals of special concern which could inhabit the irrigation ditches on the project site ' include giant garter snake (Thamnophis couchi i as) and California red-legged frog Rana aurora dra toni . However, the giant garter snake probably doesn't inhabit the main drain because the ' ditch is relatively small and is periodically cleared out. Red-legged frogs may have occurred in the project area in historic times, but they were not observed during the field surveys. River otter Lutra canadensis) may explore the main drain during winter months when the water level is ' high. However, due to the fluctuating water level in the irrigation ditches, the.limited food base, and that no otters were seen during the field surveys, a resident population of otters is unlikely. Turtles observed in the main drain could have been southwestern pond turtles Clemm s mannota ' mannorata) which are considered species of special concern by the State Department of Fish and Game and a candidate, category 2 species, by the U.S. Fish and Wildlife Service. Willow Scrub Riparian Willow scrub riparian vegetation is located on the south-eastern portion of the project site ' where several drains come together and accounts for approximately 2.1 acres of the project site. Typical vegetation types include arroyo and black willows Salix lasiolepis and S. lasiandra , cattail, bulrush, lizards tail (Anemopsis califomica), creeping wild rye El mus triticoides , and ' cottonwood trees Po ulus fremontii . This habitat provides water, cover and a source of food for several wildlife species. A ' pair of great horned owls Bubo virginianus) utilize the willow scrub riparian vegetation for roosting during daylight hours. Special-status animals which may utilize the willow scrub riparian habitat include long- eared owl Asio otus and the salt marsh yellowthroat Geothl is.trichas sinousa . The presence 3-82 1 1 1 ' of salt marsh yellowthroat on the project site would be at the westernmost fringe of this subspecies range. While it is possible that yellowthroats may attracted to the willows on the project site, the small size of this area would not represent prime nesting or foraging habitat. Wetland Habitat ' A wetlands "Delineation Report" for the proposed project site has been prepared by Huffman & Associates, Inc. and is contained in Appendix D of this EIR. The purpose of this report was to delineate and map the extent of all "waters of the United States" including ' wetlands, located on the project site, that would be subject to the provisions of Section 404 of the Clean Water Act. Filling in waters of the United States' ("waters") requires a permit from t the Department of the Army,U.S. Army Corps. of Engineers. The Army Corps of Engineers has confirmed the findings of this report in a letter dated September 27, 1991 (see Appendix D). ' Field surveys of the project site were conducted on June 18 and 19, 1991 to identify and map waters including wetlands present on the project site. The vegetation and wildlife characteristics of the wetlands present on the site are described above under "Salt-Affected ' Meadows and Scalds", and "Willow Scrub Riparian". Figure 3.4-2 depicts the location of wetlands located on the project site. Seasonal ' wetlands (prefix SW) are present on approximately 6.52 acres of the project site. Seasonal wetlands SW-1 through SW-9 are salt affected meadows and scalds, while SW-10 is willow scrub. Other regulated waters include the main drain ditch (indicated as CH-1) which is ' approximately 20 feet wide and traverses the northern portion of the project site. This ditch is a remnant historic natural drainage channel that has been channelized for irrigation use. This ditch totals 2.66 acres. ' The project site once contained additional wetland areas prior to construction of the existing levees and reclamation of Hotchkiss Tract. Since the turn of the century agricultural ' practices have been conducted on most of Hotchkiss Tract. This agricultural activity has resulted in most of the wetland habitat and characteristics of the area being significantly altered or destroyed. However, wetland habitat and wetland characteristics are still present in some low tlying locations which were not suitable for agricultural production. For this reason much of the project site does not exhibit wetland characteristics even though the soils in the area may exhibit wetland hydrologic characteristics. As discussed above, only 9.18 acres of the project site contains wetland or waters of the United States as defined by the US Army Corps of Engineers' criteria. ' Other Special-Status Species The list of special-status plants and animals potentially occurring in eastern Contra Costa County includes several taxa that rely on habitats that are not present on the project site. 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'. ?f Y • 'i rr:•6 lj, Maps * i :x, ••� +y Y Je f. y�.v` Sw!• '�ji�s„�If - - t.a 1r•r"r�• l r�y� �' I - r � .. `i•q ik IF If .+.• � /i',tl� y •js �� �� . .""'r+,,�..�:Sid:'t_,�_ f. y�« �,"fi•i�•�+• � + 1.34 Y 1" "j'../a r` • ..�' .A a' � ! - .r • 1• t,i• .. Il�a ' .'n, •.w.w. '„' ''� 1 r+,lr �`v '{,r•�a• l+ �,. � - '�'•� � � 1 r i'�: \•:•;l J; .r• �•.}' ,ry,ti; .. �,� .t�� •e� ,'!n, �k� F ,. l�, I r.- 1,�,''{la *�!� ' � Txr t ���'i«ii'°°1" j,�+ +k, a., y y, -.i#.:•.�: •t. ! `�t'• # l . (,' �g't�t 1 =r• i , a t •a •i i •�.� ' i• )i w.•«•Y:.x� �y f, a,.sa «M�TII•�"• ��+”4• .tt. r 7 �, �, r .is• "."3�.. „i t.. ,� ' 't+ Oil•i�, i C •Yyt� 7��,�, O i+S �a` aa,l M t ,•• -�. ,7174.+' ,'4..- ter,• yy(, •r 'e'� t'„ R 1'Jr :t et^'' I•�„I(` .� d , w�'n�vt' �`'' Y�'t>It:t. M' •a•X fh. '' ' ) tl, 'S• 1 Y i It �• C�,{ f� �t}t4�"•,A,}.� 1 ,a ':t. ,err' f ..t1 �;,�', it + •`V xr Og Op ' yN.7f �rh+�fH{t;td` �•i I�.r.; r r.•:rr , •/1: �f4`f,:tom. 41.f . �h= ,'�yJo{y � •��flX * j• '�'��j �•}�a'ti`� .r�• l �i_ �.t���',,YI. ✓y 4 y�, a' t �Y..•lri• + "'w'J 'f..t.t' .M� " i � '+ ,It �4r1 4;'•, 1f1.�+.. i %. •:1l ''• Y '''t..!A. {, :, .. ti. 16. • ! tr .v ''4, .! 'f "tj .etw:h,e f i occur on the project site. Northern California black walnut Ju Tans hindsii is also not present on the project site. Two of the special-status insects, elderberry longhorn beetles (Desmocerus california dimorpha and Lange's metalmark (Apodernia mormolangei), rely on specific host plants which are not present on the project site (elderberry bushes and buckwheat). Other special-status animal species such as California black rail (Laterallus iamaicensis coturniculus and California clapper rail (Rallus longirostris obsoletus are not present.onthe project site due to the small, patchy and inpersistent habitat present on the project site. The Suisun song sparrow (Melospiza melodia maxillaris is also not thought to be present on the project site because its distribution is well known and restricted to unmanaged wetlands in the Suisun area. Contra Costa County General Plan 1991 - Vegetation and Wildlife Policies The Contra Costa County General Plan defines the most significant ecological resources of the County into three separate categories: 1) areas containing rare, threatened or endangered species; 2) unique natural areas; and 3) wetlands and marshes. These three categories overlap somewhat because many times unique natural areas also contain habitat for rare, threatened and endangered animal or plant species. The Contra Costa County General Plan identifies several significant ecological areas in the project vicinity. These include: Bethel Island Wetlands which are located along the north portion of Bethel Island, supports approximately 741.5 acres of seasonal and permanent wetlands. Another approximately 940 acres of ruderal wetland/upland are found within the Bethel Island planning area. These have high value as biological habitat and are considered critical natural resources by the U.S. Army Corps of Engineers and other resource agencies. Franks Tract is a flooded, formerly levee-encircled, delta island located northeast of the project site. This area contains freshwater marsh and riparian woodland habitats on borders, and delta aquatic habitat with good spawning area for fish (striped bass, largemouth bass, white catfish, other). The area also contains possible habitat for giant garter snake. Sand Mound Slough is located east of the project site and contains examples of habitat found on the tule islands in the central and southern Delta, This area contains tules, bulrushes,common reed,rushes and other marsh vegetation as well as riparian vegetation which provides valuable habitat for wintering ducks and other waterfowl. The Contra Costa County General Plan contains specific Policies for the protection of native vegetation and wildlife within the County. Several of these policies pertain to 3-85 development on proposed project site and are listed below. Consistency with these policies is ' discussed in the Impacts section. • Significant trees, natural vegetation,and wildlife populations generally shall be preserved. ' (Policy 8-6) • Important wildlife habitats which would be disturbed by major development shall be preserved and corridors for wildlife migrations between undeveloped lands shall be retained. (Policy 8-7) • Areas determined to contain significant ecological resources,particularly those containing endangered species, shall be maintained in .their natural state and carefully regulated to ' the maximum legal extent. Acquisition of the most ecologically sensitive properties within the County by appropriate public agencies shall be encouraged. (Policy 8-9) • The County shall utilize performance criteria and standards which seek to regulate uses in and adjacent to significant ecological resource areas. (Policy 8-11) • Natural woodlands shall be preserved to the maximum extent possible in the course of ' land development. (Policy 8-12) • The ecological value of wetland areas, especially the salt marshes and tidelands of the bay ' and delta, shall be recognized. Existing wetlands in the County shall be identified and regulated. Restoration of degraded wetland areas shall be encouraged and supported ' whenever possible. (Policy 8-17) • The filling and dredging of lagoons,estuaries, and bays which eliminate marshes and mud flats shall be allowed only for water-oriented projects which will provide substantial public benefits and for which there are not reasonable alternatives, consistent with State and federal laws. (Policy 8-18) • Fish, shellfish, and waterfowl management shall be considered the appropriate land use for marshes and tidelands, with recreation being allowed as a secondary use in limited locations, consistent with the marshland and tideland preservation policies of the General Plan. (Policy 8-20) The planting of native trees and shrubs shall be encouraged in order to preserve• p g g p se a the visual integrity of the landscape, provide habitat conditions suitable for native wildlife, and ensure that a maximum number and variety of well-adapted plants are sustained in urban areas. (Policy 8-21) • The County shall strive to identify and conserve remaining upland habitat areas which are ' adjacent to wetlands and are critical to the survival and nesting of wetland species. (Policy 8-24) ' 3-86 • The County shall protect marshes, wetlands, and riparian corridors from effects of potential industrial spills. (Policy 8-25) Seasonal wetlands in grassland areas of the County shall be identified and protected. (Policy 8-27) Seasonal wetlands in grassland areas of the County shall be identified and protected. (Policy 8-28) The above list does not represent all policies in the Contra Costa County General Plan which pertain to vegetation and wildlife but rather only a select few which are pertinent to development on the proposed project site. The Contra Costa County General Plan also sets forth the following "Implementation Measures" regarding wetland areas: • Update and maintain detailed maps of the significant ecological resource areas and use them in the environmental review process to determine potential impacts upon these resources. (8-d) Prior to the approval of discretionary permits involving parcels within a significant ecological resource area, the County shall require a biotic resource evaluation based upon field reconnaissance performed at the appropriate time of the year to determine the presence or absence of rare, threatened or endangered species of plants or animals. Such evaluation will consider the potential for significant impact on these resources, and measures proposed to mitigate such impacts, where feasible, or indicate why mitigation is not feasible. (8-e) • Prepare a list of standard mitigation measures from which the County could select appropriate measures to mitigate the impacts of projects in or adjacent to significant ecological resource areas. (8-f) Require the environmental impact analysis of all significant grassland sites proposed for development to include an early spring site reconnaissance to determine the presence of vernal pools and rare species associated with vernal pools, and document the use of any seasonal wetlands by bird species. A general observation of such sites during the dry portion of the year shall be deemed insufficient for environmental review. Significant grasslands include generally parcels of more than 40 acres which are located in as area dominated by native or introduced grass species. (8-g) • A setback from the edge of any wetland area may be required for any new structure. The breadth of any such setback shall be determined by the County after environmental review examining (a) the size and habitat value of the potentially affected wetland, and (b) potential impacts on the wetland, and adjacent uplands, arising out of the development 3-87 and operation of the new structure. Unless environmental review indicates that greater ' or lesser protection is necessary or adequate, setbacks generally will be between 50 and 100 feet in breadth. Expansion of other modifications of non-habitable agricultural-related structures existing as of 1990 shall be exempt from this setback requirement. Parcels ' which would be rendered un-buildable by application of this standard shall be exempt.. (8-k) Wetlands Protection Ordinance Draft December 14 ' The County is also working on a et ( be , 1992), which identifies the County's goals regarding the protection and replacement of impacted wetlands within-the County. The draft ordinance identifies that avoidance of wetland areas by 1 development is preferred. However, if wetlands will be impacted that compensatory mitigation should be provided. The draft ordinance calls for a Restoration Plan to be prepared when wetlands will be impacted. The Restoration Plan should provide for in-kind mitigation, rather than out-of-kind whenever possible; mitigation monitoring fees to ensure.continued management and restoration; and replacement ratios up to 3:1 but no less than 1:1. IMPACTS Direct On-Site Impacts to Existinll Vegetation and Wildlife Habitat ' The proposed project would result in grading and excavation activities on the majority of ' the 685.9 acre project site for the development of 1,330 residential units, golf course, lakes and channels and other associated facilities. The project would avoid impacting most wetland areas on the site. For this reason the majority of the existing grassland, stabilized dunes, cropland, ' pastures and salt-affected meadows and scalds would be removed and replaced with urban and suburban uses. The impacts of the proposed project on each of the habitat types present on the project site are discussed in detail below. ' Developed/Residential Developed/residential uses are located in the northern portion of the project site. This , habitat type accounts for approximately 10 acres of the project site. No special status species were present during the field survey or are known to inhabit such areas. , Development of the proposed project would remove the existing developed/residential uses on the site and replace it with single family residences and the proposed golf course. Since no ' special-status plant or animal species are known to inhabitant or utilize this area, this impact is not considered significant. Non-Native Annual Grassland Non-native annual grassland habitat covers approximately 170 acres of the project site ' both north of Cypress Road and south of Cypress Road in the southwest corner of the project site. The non-native annual grassland habitat provides foraging and cover habitat for black-tailed ' 3-88 ' jackrabbit, California ground squirrel, red fox, and burrowing owls; and could support prey species for kites, short-eared owl, golden eagle and prairie falcon. ' The proposed project would result in removing approximately 170 acres of non-native grassland and replacing it with single family residences and recreational uses. North of Cypress. Road the non-native annual grassland habitat would be developed with single-family residences, t several golf course holes, a driving range and the golf course clubhouse. In the southwest corner ' of the project site, the non-native annual grassland habitat would be developed with single-family residences, a project lake and a park. Removal of this habitat would not affect any special-status plant species; however, removal of this habitat may affect several species of special concern ' which may utilize this habitat for foraging. Development of the project site would contribute to a incremental loss of foraging habitat in the County and region for the special-status species which may utilize the site. However, abundant similar habitat is present in the vicinity of the ' project area outside the Urban Limit Line which would not be developed. In addition, delta habitat, which is considered superior to the habitat on the project site for supporting special-status species, would remain undeveloped. 1 Non-Native Annual Grassland/Interior Stabilized Dunes ' The non-native annual grassland/interior stabilized dune habitat is scattered throughout the non-native annual grassland located north of Cypress Road on the project site. As stated previously this habitat is highly degraded and shows little native characteristics. This habitat type ' accounts for approximately 12 acres of the project site and is known to provide habitat for several special-status plants, insects and animals. However, none of these species was observed or is thought to be present on the project site due to the degraded nature of this habitat. ' The proposed project would result in removal of the 12 acres of non-native annual grassland interior stabilized dunes for development of the proposed golf course. However, this ' habitat is highly degraded and no special-status species were observed during field surveys and are not thought to be present on the project site. Therefore, this impact is not considered to be significant. ' Annual Crop Land The vegetative character of the annual croplands is primarily weedy. This habitat may provide foraging ground for small mammals and several birds of prey which are considered ' species of special concern by the California Department of Fish and Game. Development of the proposed project would result in the removal of approximately 115 ' acres of annual croplands present on the project site for development of urban and recreational uses. This change would not affect any special-status plants but could indirectly affect several birds of prey, considered to be species of special concern by the California Department of Fish ' and Game, by removing foraging habitat. While the loss of foraging habitat by itself would not ' 3-89 1 be considered significant impact of the project,loss of this habitat would contribute incrementally , to the cumulative loss of foraging habitat in the County and region for special-status birds of prey. However, the County has established an Urban Limit Line outside of which no ' development is allowed (approximately 65% of the County). The areas outside the Urban Limit Line will provide long-term foraging habitat and Iimit the cumulative loss of habitat in the County and region. Irrigated Pasture and Hayfields The irrigated pasture and hayfields on the project site account for approximately 275 acres of the project site. These areas are primarily located adjacent to and north of Cypress Road and in the northern corner of the project site near the intersection of Bethel Island Road.and Sand ' Mound Road. This portion of the project site would be developed primarily with single-family residences and portions of the proposed golf course. The irrigated pasture and hayfields do not contain any special-status plant species or provide significant habitat for any known special-status ' animals, birds or insects because of the relatively intensive agricultural use of these areas. Therefore, the conversion of this habitat to urban uses is not considered significant. Salt-Affected Meadows and Scalds , This habitat type accounts for approximately 40 acres of the project site and is located ' north of Cypress Road and scattered primarily within the non-native grassland and in the irrigated pastures. Salt-affected meadows and scalds north of the main drain would be developed with single-family residences and portions of the proposed golf course. The salt-affected scalds located on the eastern side of the project site, in the irrigated pasture area, are located within the proposed wetland mitigation area and would not be affected by development of the project site. Approximately 4.12 acres of this habitat has sufficient duration of near-surface water to qualify , as wetlands. The majority of this habitat which qualifies as wetlands (3.8 acres) would be preserved and incorporated into either the design of the proposed golf course or the wetlands mitigation area (see discussion of Wetland Habitat Mitigation and Monitoring. Plans below).- , Figure 3.4-3 depicts the location of wetland areas impacted by the proposed project. The project would impact 0.32 acres of salt-affected meadows and scalds which qualify as wetland areas ' (SW-2 through SW-6 and SW-9). Development of salt-affected meadow and scald habitat would not affect any known plant , or animal species of special concern associated with this habitat type. The project's impact on this habitat would be less-than-significant with implementation of the project's Wetland'Habitat Mitigation and Monitoring Plan. Irrigation and Drainage Ditches Approximately 38,000 linear feet of irrigation and drainage ditches are present on the project site. The majority of this habitat is contained in the main drain which traverses the northern portion of the project site. The main drain is considered "waters" of the United States 3-90 aul salulaossV -,y unwjjnn :az)jnos -Lautmqo .10 SUTSsojo 99AGq pu-e Peou .13aroud Spu-eTj 13,ifojd ;)qlkqpaj:)udtujspuellaMjouo!julaoI _,qAj I-euosre--G p9q-m;S7fG : W113 AHIM103, C-tq:ainolq -L-euos-eaS paqanls-i Pulel:lft pufl 29 samri ssaudAD • so NINE ♦ W, UP, ��'►��, �►j♦!►,♦ ''rja! ,!.�1.*eta'► ��I�► ol 1 11 d WMA mg"j I w— Imp Igo 71 AMP, a—an AMA ' by the U.S. Army Corps of Engineers and supports a variety of plant and animal species. The main drain would be impacted in several locations by road crossings, levee construction and golf ' course construction. Approximately 0.20 acres of the main drain would. be impacted by the project in the form of culverting the main drain underneath road crossings and filling at the project's eastern and western boundaries for the project levees. Figure 3.4-3 depicts the location of the portions of the main drain impacted by the proposed project. Placing the main drain in a culvert in two locations for road crossings could result in ' impacts to plant and animals of special concern. The main drain provides important vegetative cover and may provide habitat for various special-status plant species even though none were found during field surveys. In addition, the main drain supports the greatest number and diversity of wildlife species of the habitats present on the project site. Several special-status species may utilize the main drain including the southwestern pond turtle and river otter. The proposed project would result in the removal of most secondary drainage ditches present on the site. However, these secondary drainage ditches do not meet the criteria to be considered a regulated water or wetlands by the Army Corps of Engineers. Willow Scrub Riparian Willow scrub riparian vegetation accounts for approximately 2.1 acres of the project site located along the sites southeastern boundary where several drains come together. This habitat is potential habitat for several special-status animals including long-eared owl and salt marsh yellowthroat. However, these species were not observed during field visits to the site. In addition, this habitat is considered wetlands due to its hydrologic condition and plant species. The proposed project would affect 0.43 acres of this habitat (SW-10) through the construction of the project levee. The remainder of this habitat is not proposed for development and would be preserved in its present state. A minimum 50-foot wide buffer to be maintained ' as much as possible in a natural state is also proposed to surround this habitat to further protect this area from development. The project's impact to this wetland area would be minimal but would be mitigated through replacement and enhancement of other wetland on site (see Wetland Habitat discussion below). The project's proposed Wetland Habitat Mitigation and Monitoring Plan would reduce this impact to a less-than-significant level. Wetland Habitat The project site contains approximately 6.52 acres of seasonal wetlands and 2.66 acres of waters of the United States associated with the main drain, for a total of 9.18 acres of waters/wetlands on the project site. The amount of waters/wetlands on the project site has been verified by the U.S. Army Corps of Engineers in a letter dated September 27, 1991 (see Appendix E). Of the 6.52 acres of seasonal wetlands on the project site, the proposed project would avoid approximately 5.77 acres of wetlands and impact 0.75 acres. The location of seasonal wetland areas impacted is depicted in Figure 3.4-3. The small wetland areas, located north of Cypress Road in the center of the top portion of the project, will be avoided and preserved. 3-92 The wetland area located south of Cypress Road, along the easterly boundary of the project would be minimally impacted. The largest of the wetland areas located north of Cypress Road along the easterly boundary (SW-7 and SW-8), will be avoided and preserved as part of the , project. Of the 2.66 acres of waters of the United States on the project site, the proposed project would avoid 2.46 acres and impact 0.20 acres. The location of waters of the United States impacted by the project are depicted on Figure 3.4-3. Wetland Habitat Mitigation and Monitoring Plan , As indicated above, the proposed project would impact approximately 0.95 acres of ' waters/wetlands for development of the project levee, homes and other amenities. The project plans include a Wetland Habitat Mitigation and Monitoring Plan (see Appendix D) which is designed to replace impacted wetlands by enlarging and enhancing the existing wetlands on-site. The-goal of the mitigation plan is to create an additional 2.28 acres of seasonal wetlands by enlarging and enhancing the existing wetland located north of Cypress Road along the easterly boundary of the project site (SW-7 and SW-8). 'The wetlands in this area are presently two separate wetlands. The additional acreage would be created in the middle of these two areas, making the area one contiguous wetland. The wetland mitigation area is depicted in the draft Habitat Mitigation and Monitoring Plan contained in Appendix D. The draft Mitigation and Monitoring Plan discusses the method of mitigation and monitoring techniques. This plan was prepared consistent with the guidelines prepared by the Corps on habitat mitigation and monitoring. The applicant proposes to submit a final plan to the Army Corps of Engineers for. ' review and approval.prior to approval of the project's final subdivision map. In addition to the creation of new wetland areas, the project design would includes buffer areas around the wetland areas. The buffers would range in width from 50 to 100 feet in width depending on adjacent activities. The buffer areas would be planted with transitional vegetation progressing from wetland plant species next to wetland areas to more upland vegetative species ' near the outer edge of the buffer zone. The buffer areas are intended to protect the wetland areas from human activities and nearby urban activities. Channel Enhancement Plan The project site contains a drainage ditch (approximately 2.66 acres), which runs west to ' east across the northern portion of the site. The project plans call for the enhancement of this drainage ditch into a channel of approximately 8.0 acres in size. A new channel is also proposed in the north/south direction and would connect to the proposed lake. This second channel would be approximately 11 acres is size. The channels are proposed to provide additional riparian habitat and visual interest to the project. The banks of the channels would be sprigged with ' willow and cottonwood cuttings to provide riparian cover. The cuttings would be randomly 3-93 i ' placed at an average of 50 feet in groupings of 3. Voluntary willows and cottonwoods are also expected to sprout along the channel banks. The proposed channels would provide greater area for wildlife species than presently exists on the project site, such as the great horned owl and pond turtles. There are other species ' that were not observed during the field surveys that are likely to inhabit the channels. These species may include the giant garter snake, California red-legged frog and river otter. These species are not presently on the site because the existing channel is too small and the water level ' fluctuates. The proposed channels would be designed so that water levels would not fluctuate. Human activity around the channels would be limited. No human contact (boating, ' swimming) would be allowed in the channels to maintain acceptable water quality. The project also proposes a pedestrian trail along much of the east/west channel which would provide the opportunity for wildlife observation. Informational signage could be used to warn trail users of ' the sensitive habitat and provide educational information about the habitat and wildlife species present. ' Impact on Special-Status Species No special-status plants, animals or insects were observed on the project site during field ' surveys conducted in May and September 1991. In general, the habitat present on the project site does not represent important habitat for special-status plant, animal and insect species occurring in East Contra Costa County. One exception is the primary drainage ditch ("main ' drain") which runs through the project site. This drainage ditch may provide habitat for various special-status plant and animal species, however, none were observed during field surveys. Special-status species which may utilize this ditch include the southwestern pond turtle and the ' river otter. The proposed project would have a less-than-significant impact on special-status plants, animals and insects because: 1) The project site does not contain important habitat areas; and 2) The primary drainage ditch would be enhanced as part of the project to provide additional wildlife habit (see discussion of Channel Enhancement Plan above). Additional mitigation may be necessary for roadway crossings of the channel to avoid the movement of wildlife along the channel. ' Indirect Impacts to Vegetation and Wildlife Habitats The existing vegetation and wildlife habitats on the project site are characterized as primarily agricultural in nature. Due to continued disturbance and human activity, the project site exhibits less species diversity and habitat quality than native delta lowland habitat. As ' discussed previously, the project site does not contain any special-status plants. However, the project site may provide foraging habitat and cover for several bird species of special concern. Development of the project site would not in and of itself be considered a significant loss of ' foraging habitat for the special-status birds of prey because the site is somewhat degraded by ' 3-94 agricultural activities and does not represent the loss of the last piece of rural agricultural land , in the project vicinity. While foreseeable development on neighboring properties may result in additional loss of foraging habitat for special-status birds (see Cumulative Impacts discussion, Section 5.2), there will remain abundant habitat-in surrounding areas which is not available for ' development as a result of zoning or other land use restrictions, including the County Urban Limit Line. This includes much of the delta area located to the north and east of the project site which contains significantly better quality wildlife habitat than the project site. ' While there is substantial wildlife habitat in surrounding areas to support local vegetation and wildlife species so that development of the project site would not be considered a significant ' reduction in local or regional habitat; the proposed project could affect the quality of adjacent habitat, primarily the. San Joaquin-Sacramento Delta, through the creation of additional urban pressures on these areas (see Section 5.2 Cumulative Impacts.) The proposed project would ' increase human activity adjacent to the San Joaquin-Sacramento Delta in the form of additional boating, fishing and other recreational activities on delta waterways. While the project's , contribution to the total number of people using the delta would be insignificant, the project would contribute incrementally to the increasing pressures on the delta and impacts on delta wildlife and wildlife habitats. However, such pressures have; been substantially limited in Contra , Costa County through establishment of the Urban Limit Line and the 65/35 Land Preservation Standard. Conformance with County Vegetation and Wildlife Polices , As identified in the setting section, Contra Costa County has numerous policies, ' implementation measures and a draft ordinance which address the preservation and maintenance of the County's vegetative an wildlife resources.. Many of these policies are similar in their intent. The following discussion identifies how the proposed project generally relates to the t County's policies regarding preservation,maintenance and replacement of the County's vegetative and wildlife resources. The proposed project would not directlyaffect significant ecological areas identified on ' g g the Contra Costa County General Plan in the project vicinity. The Bethel Island Wetlands are located along the northern portion of Bethel Island approximately 3 miles from the project site. ' Franks Tract is also located sufficiently north of the project site not to be affected by the proposed project. Sand Mound Slough is located near the eastern boundary of the project site across Sand Mound Road and the existing levee system. The proposed project would not have ' a significant effect on Sand Mound Slough because no breach of the existing levee is proposed and most of the mainland side of the existing levee between the project site and Sand Mound Slough has been developed with single-family residences and businesses. , The proposed project addresses the vegetation and wildlife policies and wetland standards of the Contra Costa County General Plan in the following ways: ' 3-95 ' The project would not involve filling or dredging of lagoons, estuaries or bays. • Recreational, rather than residential uses are proposed adjacent to wetland areas to reduce ' urban impacts. • The main drain and wetland areas present on the project site would, for the most part, be preserved. These areas represent the most significant natural vegetation, important wildlife habitats, the only natural woodlands on the project site, and have been identified as possibly being utilized by animal species of special-concern. 1 • Seasonal wetland in grassland areas have been identified (9.18 acres) and would be, for ' the most part, avoided and preserved (8.23 acres avoided, 0.95 acres impacted). • Waters/Wetland areas on the project site have been mapped and would be, for the most ' part, preserved in their present state. The project design also includes replacement of wetlands impacted by the project through enhancement of the habitat associated with the main drain. Buffers around wetland areas (minimum 50 feet) would also be provided to protect these areas and provide additional upland habitat. • The project would provide buffer areas (minimum 50 feet) around wetland areas present ' on the project site to protect their natural characteristics. MITIGATION MEASURES The project plans include the following mitigation measures: ' 3.4-1 Wetland Habitat Mitigation Monitoring Plan which is designed to replace impacted wetlands by enlarging and enhancing the existing wetlands on-site. The goal of the mitigation plan is to create an additional 2.28 acres of seasonal ' wetlands by enlarging and enhancing the existing wetlands on-site. Buffer areas around wetland areas would also be provided. t3.4-2 Channel Enhancement Plan which would enhance and widen the existing primary drainage ditch to a channel of approximately 8 acres in size. A new north/south channel would also be created to connect to the proposed lake. The channels ' would be sprigged with willows -and cottonwood cuttings to provide riparian habitat. Additional Mitigation Measures ' Irrigation and Drainage Ditches The proposed project would result in direct impacts to the primary drainage channel ' ("main drain") through the construction of project roadways and project levees. Impacts would 3-96 t primarily be in the form of placing the main drain in a culvert and filling portions of the,channel in the areas impacted. The project includes a Channel Enhancement Plan to mitigate Project impacts to the main drain. The following mitigation measure is proposed to furtber.r6duce the * impacts of proposed roadway crossings of the main drain to a less-than-t significant level: 3.4-3 The proposed project includes widening of the primary drainage channel ("main drain") and the creation of additional channels on the project site to improve wildlife habitat and the visual quality of the project. The project applicant should prepare a detailed Channel Enhancement Plan. based on the draft Channel Enhancement Plan provided by the applicant. The Plan should be submitted to Contra Costa County, the California Department of Fish and Game and the U.S. Army Corps of Engineers for review and approval prior to approval of the project's final subdivision maps. (Responsibility: Project Applican't/California Department of Fish and Game/U.S. Army Corps of Engineers/Contra Costa County) ,. 3.4-4 To -minimize, impacts to wildlife movement along this drainage channel, road crossings should utilize clear span bridges if feasible. If culverts are to be used they should be as large as possible to minimize impacts to wildlife movement. The design of all bridges and/or culverts to be placed along the primary drainage channel ("main drain") shall be submitted for review and approval to Contra Costa County Department of Public Works, Reclamation District 799, California Department of Fish and Game and U.S. Army Corps of Engineers prior to filing a final subdivision map. (Responsibility: Project Applicant/Contra Costa County/Reclamation District 799/California Department of Fish and Game/U.S. Army Corp of Engineers) Imp lementation of the project's Channel Enhancement Plan and the mitigation measures described above would reduce the project's impact on the irrigation and drainage ditches to a less-than-significant level. Wetlands Habitat The proposed project would result in approximately 0.75 acres of wetlands being filled for development of the proposed project. Filling of wetlands on the project site may adversely affect special-status plants and animals. The project includes a Wetland Habitat and Mitigation Plan intended to replace wetlands impacted by project construction, on-site and in a ratio of 3 acres to every 1 acre impacted. The following mitigation measures are proposed to ensure that the project's plans are implemented and successful so that the project's impacts on wetland areas , is reduced to a less-than-significant level: 3.4-5 The project plans include a draft Habitat Mitigation and Monitoring Plan which proposes to replace wetlands on-site,,in a ratio of 3 acres for every 1 acre impacted (035 acres impacted to be replaced with 2.28 acres of new wetland) by 3-97 1 ' enlarging and enhancing the existing wetlands on the project site and providing buffer areas around wetlands. The Habitat Mitigation and Monitoring Plan should be reviewed and approved by the County, California Department of Fish and ' Game and U.S. Army Corps of Engineers prior to filing a final subdivision map. (Responsibility: Project Applicant/Contra Costa County/California ' Department of Fish and Game/U.S. Army Corp of Engineers) 3.4-6 Wetlands and waterways impacted by the proposed project are considered waters of the United States and therefore come under the jurisdiction of Section 404 of ' the Clean Water Act. Filling in waters of the United States requires a permit from the Department of the Army, U.S. Army Corps of Engineers. The project ' applicant is required to obtain a permit from the U.S. Army Corps of Engineers before filling of any wetlands or waters on the project site. The type of permit required will be defined by the U.S Army Corps of Engineers upon submittal of ' a permit application by the project applicant. In addition to the U.S. Army Corps of Engineers permit, the California Department of Fish and Game may need to be notified regarding project activities in the vicinity of the main drain pursuant to ' Fish and Game Code Section 1600 et. seq. (Responsibility: Project Applicant) (Note: application for, and issuance of CDFG and Corps permits is conducted after ' completion of the environmental review process per state and federal regulations) 3.4-7 The project should pay the County Protection Fee, as required by the County ' General Plan, for acquiring development rights on wetland areas off-site. The Protection Fee should be paid upon the issuance of building permits for the project. (Responsibility: Project Applicant) ' Implementation of the above mitigation measures will reduce the project's potential impacts on wetlands and waters of the United States to a less-than-significant level. 1 3-98 3.5 VISUAL QUALITY , EXISTING SETTING Regional Landscape and Scenic Resources 1. The project site is located in northeastern Contra Costa County adjacent to the San Joaquin-Sacramento River Delta. Significant scenic resources located in the area include the delta waterways and islands, low lying agricultural fields and scattered orchards, and flood control levees along delta waterways. On clear days, Mount Diablo and the Diablo range are visible to the west. These ' mountains provide a significant backdrop to the rural views from many vantage points in the project area and vicinity. As discussed in Section 3.1 under existing land uses, the Hotchkiss Tract primarily 1 consists of low-lying agricultural lands with a few scattered orchards and residences (see Figure 3.5-1). These land. uses provide a rural visual character with many opportunities for long ' distance views. Drainage ditches which traverse the area are often filled with cattails and other wetland vegetation providing a break in the relatively continuous agricultural views. In addition, different agricultural practices (e.g. orchards, row crops, cattle grazing, irrigated pastures) add ' a "patchwork" visual character to this rural area. Residences in this area often times continue this rural theme with ranch-style architecture and associated barns (see Figure 3.5-1). The large flood control levees which line the delta waterways provide another unique ' visual image to the project area and vicinity. In the project vicinity these levees are lined with homes on the landward side. Many of these homes are constructed with living spaces either at or above the top of the levees, often three and four stories tall. In other areas, the landward side of the levee is undeveloped and grasses grow on the levee slopes. Visual Character of the Pro'ect Site ' The visual character of the project site is rural/agricultural. The project site is ' predominantly flat. The visual character of the project site can be divided into four basic types: 1) areas with short grasses used as range land for cattle grazing; 2) irrigated pasture for horses; , 3) irrigated areas used for the cultivation of row crops; and 4) areas where residences and farm structures (barns, equipment storage, etc.) are located. These uses provide a relatively constant visual image over most of the project site (see Figure 3.5-1). However, the different agricultural , practices create a "patchwork", or mosaic, pattern to the land. In addition, several drainage ditches traverse the project site breaking up the relatively constant agricultural view. Several rural residential structures and associated barns and other buildings are located ' on the project site. These structures break-up the agricultural/rural visual image, but would not be considered significant visual features due to their age and condition (see Figure 3.5-1). , 3-99 :'',.: 1 . �• � �. •' R•. ��� Oji;ty I - • C i'1 7 �C- - _ wF r 1, r/ • �7 ty. ,y, ' Other man-made visual features located on the project site include the 3 large power lines which traverse the southwestern corner of the project site. The power lines are visible from most vantage points on the project site and break-up the continuity of the views to the west toward Mount Diablo and the Diablo range. Another electrical transmission line is currently under construction in the area. ' Existing Views from Local Roadways and Vantage Points ' Existing views from Bethel Island Road to the east are across the agricultural uses on the project site and the existing residential uses which line the flood control levee along Sandmound Boulevard. ' Existing views to the west from Sandmound Boulevard are of wide expanses of agricultural uses including those on the project site. Mount Diablo and the Diablo range are ' visible in the distance. However, because of the distance from the project site to Mount Diablo, often times smoke and haze obscure the mountains making them less visible (see Figure 3.5-2). The delta waterways and their associated visual resources are not visible from the local roadways and vantage points because of the flood control levees. The Delta areas are only visible from the top of the existing levees and the Bethel Island Road bridge (see Figure 3.5-3). Visual Resource Policies t The Open Space Element of the General Plan contains specific goals, policies and implementation measures for the protection of scenic resources within the County. The General Plan identifies the delta system adjacent to the project site as a major scenic resource. ' The following Scenic Resource Goals and Policies from the General Plan would pertain to development on the project site. This list does not represent a complete list of the Goals and ' Policies, but only those which specifically pertain to development on the project site. Consistency with these policies is discussed in the Impacts section (see page 3-104). ' To preserve and protect areas of identified high scenic value, where practical, and in accordance with the Land Use Element map. (Goal 9-D) ' To preserve the scenic qualities of the San Francisco Bay/Delta estuary system and the Sacramento-San Joaquin River/Delta shoreline. (Goal 9-F) ' In order to conserve the scenic beauty of the County, developers shall generally be required to restore the natural contours and vegetation of the land after grading and other ' land disturbance. Public and private projects shall be designed to minimize damages to significant trees and other visual landmarks. (Policy 9-12) 3-101 .' t :Z 1< 3aYr rJi to y'�.t F ;. 1F r_ �, �`� ..�� • up 41 14, AIV la- 17 10 to t t • 1. � '�. , •'��.` .t .� ti'• . jF- tit' , ';`. y{It 4.1�'.;'..a.' ) :4• _jy�.�'{ltd •.. '�; �5��.`i, t, ,`, Lr_; t4,. 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T�1 r„ z r a,n .,g p is 1 �j.j r a* j ;i '�� t�`.+•`<w tae "�..'"`*`.,,-'..' l 'V.ti rte` s i - t i • i Providing public facilities for outdoor recreation should remain an important land use objective in the County, as a method of promoting high scenic.quality, for air quality maintenance, and to enhance outdoor recreation opportunities of all residents. ' -(Policy 9-13) • Any new development shall be encouraged to generally conform with natural contours to avoid excessive grading. (Policy 9-21) • The appearance of the County shall be improved by eliminating negative features such , as non-conforming signs and overhead power lines, and by encouraging aesthetically designed facilities with adequate setbacks and landscaping. (Policy 9-24) • Maintenance of scenic waterways of the County shall be ensured through public protection of the marshes and riparian vegetation along the shorelines and delta levees, as otherwise specified in this plan. (Policy 9-25) , Design Guidelines Proposed by the Project Applicant ' The project applicant is proposing the following design guidelines for the project site: • Residential units will be limited to two stories not to exceed 30 feet. ' • Minimum setbacks along arterial roadways will be 200 feet, and 100 feet from the center , line of the roadway to the exterior wall of any living space along.collectors (Cypress Road Extension). • Sideyard setbacks will vary taking into account: 1) structures should not block solar access for heating and cooling; 2) space between buildings shall increase in relation to their height; and 3) periodic view corridors to water areas should be provided. ' IMPACTS Impacts to Regional Landscape and Scenic Resources The San Joaquin-Sacramento delta waterways are identified as significant scenic resources. ' Projects which breach delta levees or include marinas or other water dependant components could result in significant visual impacts to local delta waterways. The proposed project does not involve breaching of delta levees or the development of other delta related facilities (e.g., , marinas,docks,etc.) and therefore would not directly affect the existing visual quality of adjacent delta waterways. The project would alter a portion of the Hotchkiss Tract by replacing 685.9 acres of agricultural land with urban-type uses. (see Impacts to Visual Character of Project Site below). While the proposed project would not directly affect the visual character of adjacent areas on ' 3-104 ' 1 Hotchkiss Tract, it would contribute to cumulative impacts on the overall visual character of Hotchkiss Tract. iImpacts to Visual Character of the Proiect Site The proposed project would result in changing the existing character of the project site to one of a suburban residential community with various recreational uses. This change would alter the existing visual condition, however, this change in uses was taken into consideration in the County General Plan by designating this site for some level of urban development. Different portions of the site would exhibit different visual characteristics. The southern portion of the site would be visually oriented toward the man-made lake, while the northern portion of the site would be visually oriented toward the golf course. The project design would include considerable amounts of landscaped areas including the golf course, parks, common areas, the project levees and along the channels. The project application includes landscape criteria which are designed to be in keeping with the existing vegetative character of the area. Landscaped areas would consist primarily of low grasses and wildflowers with some introduced shrubs and trees. Tree massing would occur where screening is necessary around recreation areas, the project entrance and along the neighborhood park. The landscape criteria includes a list of plant materials. These plant materials were selected based on their ability to thrive in the existing soils on the project site. The landscape criteria is contained in Appendix D. While the J ro'ect would contain open space/recreational areas, landscaping and other P features to improve the visual character of the project, the development of the site with 1,300 homes, project levee and other features, would significantly change the existing visual character of the site. This would be considered an unavoidable impact of the project. Impacts to Views From Local Roads and Vantage Points Views of the project site from Bethel Island Road, Sandmound Boulevard and other vantage points around the project perimeter would be blocked by a flood control levee which would surround the project. The flood control levee would be approximately 10 feet above sea level. The actual height of the levee relative to the ground would vary. The width of the proposed levee would be approximately 100 feet at its base. ' Views to the west from existing homes along Sandmound Boulevard would be obstructed by the levee and proposed project. The degree of impact would vary with distance, and would be highest for residences closest to the levee. The roof lines of some homes,may be visible from perimeter roadway and vantage points. The project plans include landscape guidelines for the project levees. These guidelines are contained in Appendix D, and are designed to be consistent with the landscape guidelines of: 3-105 the State Reclamation Board. The project levee guidelines address the planting of trees, shrubs and ground covers on the project levees as well as irrigation and maintenance. A list of suitable plant species is also provided in the guidelines. The project levee landscape guidelines are , designed to improve the aesthetics of the levee by providing color and texture to the levee slopes. Landscaping of the project levee would provide improved aesthetics from adjacent properties as well as from inside the project. ' In addition to the project levee landscape guidelines, the project landscape criteria discussed above, also includes the provision of additional landscaping around the outside of the i project levee such as along Bethel Island Road and Sandmound Boulevard. Additional landscaping outside the project levee would provide additional screening of the levee particularly for residents adjacent to the project site along Sandmound Boulevard. Landscaping in these areas '. should consist of trees and shrubs to provide adequate screening. The landscaping should be located sufficiently outside the levee cross-section as to not be affected by levee maintenance , activities. Even with landscaping of the levee and outside the levee, the view for residences located across from the project site along Sandmound Boulevard would change significantly with the proposed project. Landscaping would provide some improvement and soften the appearance of the levee. However, the resulting change in view with the project would be unavoidable. ' Conformance with Visual Resource Policies General Plan Policies 9-12, 9-13, 9-21, 9-24 and 9-25, apply to the project site and the project is consistent with these policies for the following reasons: • The project site is relatively flat and the proposed project would avoid excessive grading and changes to the project site's topography. Visual landmarks such as wetland areas and the willow scrub habitat on the project site would be retained in the project design. ' (consistent with Policy 9-12) • The project would include significant recreational amenities including an 18-hole golf ' course and lakes to provide scenic quality and enhance outdoor recreational opportunities. (consistent with Policy 9-13) • Theproject's design includes setbacks from Bethel Island Road, undergrounding of utility , lines, and landscaping throughout the project to improve the visual appearance of the project. (consistent with Policy 9-24) • The project does not involve breaching of the delta levee system or other associated water-related development which could adversely affect delta resources. (consistent with ' Policy 9-25) 1 3-106 ' 1 ' The final contours of the site will have a low visual profile that is consistent with the visual character of the surrounding area. Grading would be held to the minimum amount necessary to construct the levee system and other project features. (consistent with Policy 9-21) MITIGATION MEASURES The proposed project includes the following mitigation measures for visual impacts: ' 3.5-1 Landscape criteria for the proposed golf course, parks, common areas, Jro'ect P levees and the channels. Landscaping would consist primarily of low grasses and ' wildflowers with some introduced shrubs and trees. 3.5-2 Landscape guidelines for the proposed levee system. These guidelines are ' designed to be consistent with the landscape guidelines of the State Reclamation Board. A list of suitable plant species is provided as part of the guidelines. ' 3.5-3 A landscape strip would be provided outside the project levee to provide screening of the levee along Bethel Island Road and Sandmound Boulevard. The landscape t strip would be a minimum of 10 feet wide and be located sufficiently outside the levee cross-section to not hinder maintenance of the levee. The landscape strip should be planted with trees and shrubs to provide maximum screening. Maintenance of the landscape strip would be carried out by the homeowners' association or special district but not the public agency responsible for maintenance of the project levee. 3.5-4 Residential units will be limited to two stories not to exceed 30 feet. 3.5-5 Minimum setbacks along arterial roadways will be 200 feet, and 100 feet from the center line of the roadway to the exterior wall of any living space along collectors (Cypress Road Extension). 3.5-6 Sideyard setbacks will vary taking into account: 1) structures should not block solar access for heating and cooling; 2) space between buildings shall increase in ' relation to their height; and 3) periodic view corridors to water areas should be provided. Additional Mitigation for Impacts to Views From Local Roadways and Vantage Points The following mitigation measure are proposed to ensure adequate landscaping is provided: 3.5-7 The levee landscape guidelines should be finalized once the public agency to be responsible for maintaining the levees is determined. The levee landscape ' 3-107 guidelines should then be submitted to the public agency responsible for ' maintenance of the levees for review and approval prior to the installation of any landscaping on the levees. (Responsibility: Project Applicant) , While the mitigation measures described above and proposed as part of the project would reduce the visual impacts of the project levees, the impact of the project levee on views from adjacent vantage points would be unavoidable. Additional Mitigation Measures , The following mitigation measure is proposed to ensure that landscaping installed as part of the project will be adequately maintained. ' 3.5-8 A landscape maintenance district, or other funding source consisting of the ' property owners within the project site, shall be established for the proposed project to pay for long-term maintenance of public recreation areas within the project site. The project applicant shall submit a proposal for the landscape ' maintenance district to the County for approval prior to approval of the project's final subdivision map. (Responsibility: Project Applicant) 1 3-108 ' ' 3.6 NOISE EXISTING SETTING Existing Noise Environment The major noise source affecting the project site is vehicular traffic on Bethel Island Road. Traffic on Cypress Road and Sandmound Boulevard also contribute to the noise environment, but to a lesser extent. The noise from vehicles drops off significantly with distance from the roadway. Consequently, the central and eastern portions of the site are relatively quiet and dominated by noise from birds, occasional aircraft flyovers, and wind in the vegetation. ' To quantify the existing noise environment, one continuous 24-hour measurement and three short-term measurements were made throughout the project site. The 24-hour noise ' measurement was taken to monitor noise level fluctuations throughout the day, such as peak traffic commute periods to provide an.accurate overall picture of the existing noise levels in the project vicinity. Figure 3.6-1 shows the location of the noise measurements. The 24-hour ' measurement was made along Bethel Island Road near the project's western boundary. The existing day/night average sound level (DNL)' is 73 Db, approximately 30 feet east of Bethel Island Road. The existing noise level is significantly lower along Sandmound Boulevard. The noise level at these locations is a DNL of 48 dB. The existing noise level at the interior of the project site is also a DNL of 48 dB. In order to determine the DNL at locations 1, 3 and 4 as depicted on Figure 3.6-1, the short-terns 15-minute measurements were correlated with the 24- hour noise level measurement taken at location 2. Based on this comparison the DNL at locations 1, 3 and 4 was determined. Table 3.6-1 summarizes the results of the noise measurement program. The noise measurement program was conducted during the weekday because it is typically ' noisier than weekends. Although there may be a significant amount of recreational traffic on the weekends, it is unlikely that the 24-hour noise level (DNL) during the weekend would be higher than the DNL during the weekday. Acoustical Criteria ' Acoustical criteria are contained in the Contra Costa County Noise Element. The Contra Costa Noise Element contains goals,policies and implementation measures. According to Policy 11.1, new projects shall be required to meet acceptable exterior noise standards established in the Noise and Land Use Compatibility Guidelines contained in the Noise Element. Figure 3.6-2 is a reproduction of the County's table showing land use compatibility for community noise environments. The County's goal for "Normally Acceptable" outdoor noise levels in residential 1 Day-Night Average Sound Level(DNL)--A descriptor established by the U.S.Environmental Protection Agency to describe the average day-night level with a penalty applied to noise occurring during the nighttime hours(10:00 pm-7:00 am)to account for the increased sensitivity of people during sleeping hours. ' 3-109 AID Iq I � 1 � 1 ` i ' 4 2 I � I ' 1 A y1p 1 IS CLUBHOUSE \ 17 SI TE 16 x , 1 PRACTICE\Wco \� FAIRWAY -j ..- II i•/, / '.mil% •'A . 1 I 12 I ' I ' I 7 ,6 � o I Z 1 1}14 1 N l YPRE55 0OA0\ I F \ 1 1 O 3 _ I , 1 I - CYPRESS LAKES AND Figure 3.6-1: COUNTRY CLUB Noise Measurement Locations PROJECT Source: Charles M Salter Associates 3-110 ' areas is a DNL of 60 Db and for "Conditionally Acceptable" noise levels the County goal is a DNL of 70 dB. The interior goal is a DNL of 45 dB. ' Although the Contra Costa County Noise Element contains absolute noise level goals for determining land use compatibility, it is helpful to discuss the change in noise level when ' determining the impact of a project. For purposes of this analysis, a change in the DNL of 3 dB or less is considered barely perceptible and not a significant impact. A change of 4 to 5 dB is considered noticeable,.but only significant if the land use compatibility category changes from Table 3.6-1 Summary of Noise Measurements ' Cypress Lakes and Country Club 26-27 May 1992 ' A-Weighted Noise Levels (dB) Site Location Date/Time L�q Lt0 L50 L90 DNL 1 Between 4486 and 4508 Sandmound 25 May 1992 44 43 39 36 48* Blvd. 1:16-1:31 pm 30 feet east of roadway centerline End of Cypress Road 5-1/2 Feet above roadway elevation 2 30 feet east of Bethel Island Rd. 26 May 1992 72 77 67 44 -- roadway centerline 2:00-2:15 pm 1/2 mile south of Sandmound Blvd. 26-27 May 1992 71 75 63 42 75 11 feet above roadway elevation 3:00 pm 3 35 feet north of 2901 Cypress Rd. 26 May 1992 64 68 56 44 67* home facade 2:00-2:15 pm 50 feet south of Cypress Rd. ' roadway centerline 525 feet west of Bethel Island Rd. 5-1/2 feet above site elevation ' 4 feet above roadway elevation 4 Cypress Road Between Bethel 27 May 1992 46 49 41 39 48* Island Rd. and Sandmound Blvd. 4:36-4:46 pm tAmbient measurement with no traffic 5412 feet above roadway elevation *Estimate based on simultaneous measurement-at 24-hour noise measurement location. ' 3-111 Figure 3.6-2 LAND USE COMPATIBILITY FOR COMMUNITY NOISE ENVIRONMENTS COMMUNITY NOISE EXPOSURE LAND USE CATEGORY Ldn OR CNEL,d6 ' 55 60 65 70 75 80 RESIDENTIAL-LOW DENSITY , SINGLE FAMILY, DUPLEX, MOBILE HOMES RESIDENTIAL-MULTI FAMILY ;€€> TRANSIENT LODGING- MOTELS,HOTELS SCHOOLS LIBRARIES ...... ..................................:.....:::.:::::::::::. CHURCHES, HOSPITALS, NURSING HOMES AUDITORIUMS,CONCERT HALLS,AMPHITHEATRES SPORTS ARENA,OUTDOOR SPECTATOR SPORTS ' PLAYGROUNDS, NEIGHBOURHOOD PARKS ' GOLF L COURSES RIDING STABLES,WATER RECREATION,CEMETARIES , OFFICE BUILDINGS BUSINESS COMMERCIAL AND PROFESSIONAL INDUSTRIAL MANUFACTURING ?:``:':': ':'... `: «....... .... {' `> UTILITIES,AGRICULTURE NORMALLY ACCEPTABLE NORMALLY UNACCEPTABLE Specified land use is satisfactory,based upon the New construction or development should assumption that any buildings involved are of normal generally be discouraged.If new construction or ' conventional construction,without any special noise development does proceed,a detailed analysis insulation requirements. of the noise reduction requirements must be made and needed noise insulation features ® included in the design. CONDITIONALLY ACCEPTABLE ® ' New construction or development should be CLEARLY UNACCEPTABLE undertaken only after a detailed analysis of the noise New construction or development clearly should , reduction requirements is made and needed noise not be undertaken. insulation features included in the design. 3- 112 "normally acceptable" to "conditionally acceptable," or "conditionally acceptable" to "normally unacceptable." A 6 dB change or more is considered significant regardless of the land use compatibility category. This change in noise level criterion is the threshold of significance for existing housing. ' IMPACTS Compatibility of Project with Future Noise Environment ' The proposed project would increase traffic noise on Cypress Road, Bethel Island Road and Sandmound Boulevard. The proposed levee around the project perimeter would block noise from those off-site roadways, thereby reducing the noise levels on the project site to generally acceptable levels. One exception would be along the extension of Cypress.Road through the project site. Noise levels along this portion of the roadway would be considered conditionally ' acceptable for residential uses. Table 3.6-2 summarizes the change in noise levels along Cypress Road. As depicted in Table 3.6-2, the future noise level along the portion of Cypress Road within the project site would be 65 dB at approximately 40 feet, which is the typical building setback from the center line of a roadway. This situation would be 5 dB above the County's goal ' for normally acceptable outdoor noise levels but would be within "conditionally acceptable" noise levels. To avoid this potentially significant impact, the proposed project has incorporated an increased setback from the center line of Cypress Road within the project site. The proposed rproject design provides for a 100 foot setback from the center line of Cypress Road to the exterior walls of all residential uses located along Cypress Road. This setback would provide ' sufficient noise reduction so that noise levels would be within the "normally acceptable" range. Impacts of the Proiect on Adiacent Land Uses Traffic Noise Existing residential land uses are located along Cypress Road, Bethel Island Road and Sandmound Boulevard. Along Cypress Road, most of these residential uses are exposed to existing noise levels considered "conditionally acceptable" (see Table 3.6-1). Traffic noise levels ' will increase by approximately four decibels along Cypress Road due to the project. The 4 dB increase would not be considered in and of itself a significant adverse impact of the project because the housing is already exposed to "conditionally acceptable" noise levels. However, the project would add to the already high noise levels along Cypress Road. By the year 2000, traffic noise could increase an additional 2 dB as a result of other approved and pending projects, for a total of 6 dB (DNL of 70 dB). A DNL of 70 dB under cumulative development would be on the border line of normally unacceptable and would be considered adverse on the existing residential uses along Cypress Road. ' 3-113 Table 3.6-2: Noise Levels at Project Site and Off-Site Residences for Various Scenarios DNL (DB) Existing+ , Approved+ Existing + Existing+ Pending Cumulative Roadway/Link Existing Project (2000) (2010) Cypress Rd./Highway 4 to Bethel Island Road 64 68(+4 dB)2 70(+6 dB)2 69(+5)2 (typical nearest off-site residential are 80 ft. south of roadway centerline) Cypress Rd./Bethel Island Rd. to Sandmound Blvd. 48 65 65(+0 dB)2 65(+0 dB)2 (typical nearest off-site residential would be 40 ft. from roadway centerline) Sandmound Blvd./Project entrance to Cypress Road 48 48(+0 dB)' 48(+0 dB)' 48(+0 dB)' (typical nearest off-site residential are ' 45 ft. from roadway centerline) ' Expected noise level change compared to existing scenario 2 Expected noise level change compared to existing+project scenario ' Noise levels along Bethel Island Road would increase 1 dB due to the project and by an ' additional 4 dB by the year 2000. There is currently one commercial/residential land use across the site along Bethel Island Road. A 4 dB increase would not be considered a significant impact since the noise levels will remain in the "conditionally acceptable" range for the existing land ' use. Noise levels along Sandmound Boulevard would not increase as a result of the project ' because minimal traffic from the project would use Sandmound Boulevard. Most traffic would exit the project site via the Cypress Road/Bethel Island Intersection. , From a noise perspective, traffic volumes for cumulative growth (year 2010) in the area would not be significantly different than year 2000 traffic. According to the traffic volume information for the cumulative growth scenario, average daily traffic volumes along all three main roadways (Bethel Island, Sandmound, Cypress) would change by 20 percent or less when compared to the year 2000 traffic volumes. A 20 percent change corresponds to a change in ' noise levels of less than 1 dB along these roadways. Consequently, the additional growth between 2000 and 2010 would not create a significant incremental impact relative to the cumulative noise level in the year 2000. 3-114 ' Activity Noise ' Noise from general day-to-day activities at the proposed project would include people talking in backyards,people using the golf course, and possibly barking dogs. These sounds may have the potential to impact adjacent existing residences. However,this impact would only occur on-site. No off-site impacts would be expected to occur from these sources because the proposed levee would block most of these noises. Use of the levee trail may result in existing homes along Sandmound Boulevard near the southeast side of the site being exposed to increased noise ' levels as a result of activity on the levee trail. The noise level of the human voice during a conversation is 65 decibels at three feet. When existing residents along Sandmound Boulevard are in their outdoor use areas, voices from people using the new levee trail may be audible. ' Noise from the levee trail, however, would not increase the existing DNL at the homes along Sandmound. Noise from other activities on the levee trail, such..as dogs, would also not be considered a significant impact. Construction Noise Construction of the site would occur in several phases. The first phase site preparation typically involves grading and paving. Equipment used during this phase would/be heavy trucks, ' backhoes and other grading equipment. These typically generate maximum noise levels of 85 to 90 dB at 50 feet. Maximum noise levels at the nearest existing residential receptors along Sandmound Boulevard, and those properties surrounded by the site, could reach 85 to 90 dB when these equipment are operating near the property line. Typically, however, the equipment would be in excess of several hundred feet from the these locations and noise levels would be much lower. The second phase includes foundation work. Noise levels during this phase would be similar to Phase I. The third phase is construction of the buildings. During framing, maximum noise levels ranged from 80 to 85 dB at 50 feet. Noise levels would be loudest when activities are occurring nearest Sandmound Boulevard and around the homes surrounded by the project. Due to the relatively low existing noise levels on and along the east side of the project site, construction ' noise would be clearly audible and considered a significant short-term impact. MITIGATION MEASURES The following mitigation measures are proposed to reduce potential noise impacts of the project to acceptable levels. ' Cypress Road Off-Site Existing residences along Cypress Road are exposed to "conditionally acceptable" noise levels (64 dB). The proposed project would add an additional 4 dB (68 dB) to the existing condition with other development by the year 2000 adding an additional 2 dB (70 dB), for a total of 10 dB over the County 60 dB goal for residential uses. Since the existing noise levels along 3-115 Cypress Road are above the County standard, the proposed project should not be required to fully Y mitigate this pre-existing condition. However, the project, plus other development on the Bethel Island Area will contribute to this adverse impact and should be required to mitigate their fair , share as follows: 3.6-1 Noise mitigation installed (soundwalls, architectural treatments), along Cypress , Road for the project entrance to Sellers Road should be designed to achieve the County's 60 dB goal for residential uses. The proposed project should be required to pay 40% of the total cost of noise mitigation for houses along Cypress. This , is based on the calculation that the project will contribute 4 dB to the ultimate 70 dB noise level along Cypress Road which is 10 dB over the County's 50 dB goal. The remaining 60% of the cost should be paid by the County (40%) and future development (20%). The project's prorata share of noise mitigation should be paid at the time of filing each phased final map. (Responsibility: Contra Costa County/Project Applicant) Construction Noise In order to reduce construction period noise impacts the following mitigation should be implemented: 3.6-2 a. All general construction activity should be limited to the hours of 7:30 a.m. to 7:00 p.m. on weekdays only. ' b. Operations of any machine or device which generates a noise level greater than 95 dB at 50 feet should be prohibited wherever feasible. C. Route heavy construction traffic along existing Cypress Road and the proposed Cypress road to minimize the impact on existing residences. No , construction traffic should be routed along Bethel Island Road or Sandmound Boulevard. d. Prohibit construction trucks from parking along existing Cypress Road west of the project entrance. e. Locate noisy stationary equipment, such as compressors or pumping ' stations away from existing residences to reduce their noise impact. (Responsibility: Project Applicant) ' While the above mitigation will reduce construction period noise, there would still be some-times during construction of the project that noise levels would result in temporary, short- ' term, adverse impacts on adjacent residences. This temporary, short-term impact would be unavoidable. 3-116 ' Cypress Road On-Site 3.6-3 In order to avoid adverse noise levels at homes to be located along the extension of Cypress Road through the project, the project has been designed to provide a 100 foot set-back along Cypress Road. The 100 foot set-back would be from the ' center line of the roadway to the nearest exterior wall of each residence located along Cypress Road. The 100 foot set-back would reduce the noise level at these residences to a DNL of 60 dB which is consistent with the County's noise goals ' for residential uses. No additional mitigation is necessary or proposed. r ' 3-117 3.7 HYDROLOGY AND DRAINAGE EXISTING SETTING The following discussions regarding the existing drainage, levee and water quality characteristics of the project site and surrounding areas is summarized from a number of published and unpublished sources including: Evaluation of Proposed Levees Bordering Cypress Lakes Proiect, Kleinfelder, Inc., August 1992, and Informational Report for the Proposed Levee SystemBohley/Maley Associates, 1992. These reports are contained in Appendix E. , Independent technical review was provided by Bohley/Maley Associates. Drainage PROJECT SITE The project site is essentially flat ranging from almost ten feet below to 24 feet above mean sea level in one small localized area. The soils underlying the project site are composed ' of a sandy-silt with some areas exhibiting minor amounts of clay. The soils are generally loose in the upper 15 feet and become medium dense to dense with greater depth. Groundwater elevations vary with the seasons -- the depth becoming greater during late summer due to no rainfall and withdrawal of groundwater for irrigation purposes. Existing drainage is presently handled by drainage ditches that traverse the project site ' and eventually lead to Reclamation District 799 (RD-799) pumps located along Sand Mound Slough and Dutch Slough (see Figure 3.7-1). These pumps lift the waters over either the Sand Mound or Dutch Slough levees to ultimate disposal into the waters of the Delta. In general, the storm drainage system within the Hotchkiss Tract area is adequate to cant' present flows, . however, some localized flooding does occur in low areas (near some pump stations), and along Sandmound Boulevard during storm periods. The site is characterized as a "Zone A22" flood area under the Federal Emergency Management Agency (FEMA), Flood Insurance Rate Map. This characterization recognizes that the project area is susceptible to inundation to a depth of seven feet above mean sea level from either floodwater or high tides overtopping the RD-799 levee system. Under the. present regulations of the County of Contra Costa, development of the project site cannot occur without provision of adequate protection from inundation as well as the establishment of an internal drainage system. Reclamation District stnct 799 Reclamation District 799 is responsible for maintenance and operation of flood control ' and drainage systems on Hotchkiss Tract. This includes maintenance of the 6.7 miles of existing levees. Several major channels traversing the area carry water from tributary ditches in a , generally northerly direction to four pump stations and two adjacent to Dutch Slough, and two 3-118 ' Franks Tract 1 IfuY Rnnlow AN•i ��`•ry��,�� Franks Tract R.OtIWy AI..1 • `. i a Pump Stado�'i-- !t!� � + ',•�� B hel Island } l« �' `�•a. to { � r �S' ✓�,,,. krsey •" • • .1 Island s» Rad Lake ate.,as Dain a .•� •• F�Imp Station S+aa• Pum Deus stoaar Rad , \ Station Pump Station Melts Ray i1i d C1 •�` I Holland Tract ;. Project Pump Station '.. Area c as Red ~� a, Pump Stasi Figure 3.7-1: CYPRESS LAKES & COUNTRY Existing Drainage Facilities in the Project Area CLUB PROJECT 3-I29 adjacent to Sand Mound Slough (See Figure 3.7-1) In general, the storm drainage system capacity in the area is adequate to carry present flows, however, some localized flooding occurs in low areas during storm periods. ' I Reclamation District 799 has a current budget of $156,000, of which the budget for engineering is $25,000. Assessments are based on the reclamation benefit provided to the land, not on County property tax valuation. The District's current assessment .rolls are based on benefits provided to several large agricultural parcels and smaller residential lot parcels along Dutch and Sand Mound Sloughs. (Reclamation District 799, Mar. 11, 1992) Adopted Policies Regarding Storm Drainage The Public Services/Facilities, Growth Management and Conservation Elements of the General Plan contain adopted goals, policies and implementation measures to protect the public , from the hazards of flooding and to provide a surface water drainage system for projected growth in the County. These Elements of the General Plan overlap to a great extent, and all need to be consulted for a full understanding of County policies regarding flood control, waterways and ' riparian areas. The following excerpts list only those goals, policies and implementation measures which are most specifically relevant to the proposed project. Consistency of the project with these goals, policies and implementation measures is discussed in the Impacts section (see page 3-127). • To employ alternative drainage systems improvements which rely on increased retention capacity to lessen or eliminate the need for structural modifications to watercourses, whenever economically possible. (Goal 7-Q) • To enhance opportunities for public accessibility and recreational use of creeks, streams, drainage channels and other drainage system improvements. (Goal 7-R) • To ensure that new development pays its fair share of the costs related to increased runoff , created by the development. -(Goal 7-T) • To support the concept that existing development pays the cost of building and maintaining drainage improvements required to serve existing developed areas. (Goal 7-U) • Land use plans and zoning shall be the primary means for floodplain management in preference to structural improvements, where possible. (Policy 7-40) • Alternative drainage system improvements such as floodplains, leveed floodways, bypass channels and culverts, and detention basins, shall be incorporated into new flood control plans and existing plans as they are revised.- (Policy 7-41) 3-120 ' • Aesthetic, environmental and recreational benefits shall be taken into full consideration when determining the costs and benefits of alternative drainage system improvements. (Policy 7-42) • New development should be required to finance its legal share of the full costs of drainage improvements necessary to accommodate projected peak flows due to the project. Reimbursement from subsequent developments which benefit from the added capacity may be provided. (Policy 7-45) • On-site water control shall be required of major new developments so that-no significant increase in peak flows occurs compared to the site's pre-development condition, unless the Planning Agency determines that off-site measures can be employed which are equally effective in preventing adverse downstream impacts expected from the development or the project is implementing an adopted drainage plan. (Policy 7-46) • Regional detention basins shall be favored over smaller, on-site detention basins. (Policy 7-47) • Open bypass channels, detention basins and all drainage facility rights of way which are provided at different locations in order to supplement existing natural creeks should be developed as an asset to the development, e.g., as a secondary recreation use. (Policy 7-49) • Public access to watercourses shall be required of major new developments when liability, security and maintenance issues can be satisfactorily resolved. (Policy 7-51) • Detention basins shall be designed for multiple uses such as parks and play fields when not used for holding water, if liability and maintenance issues can be satisfactorily resolved. (Policy 7-52) • All residential and non-residential uses proposed in areas of special flood hazards, as shown on FEMA maps, shall conform to the requirements of County Floodplain management applied to all ordinances, approved entitlement (land use permits, tentative, final and parcel maps, development plan permits, and variances) and ministerial permits (building and grading permits). (Policy 7-57) • Create benefit assessment districts to pay for drainage maintenance activities resulting from new developments that require maintenance above the County standard maintenance activities. (Implementation Measure 7-ad) • Encourage public fee ownership of all open, government maintained drainage facilities to ensure that the adjacent developing properties contain sufficient usable area to meet the specified land use and to provide for secondary use as recreational and visual resources. (Implementation Measure 7-ag) 3-121 • Protect natural channels that are not to be maintained b government b requiring Y g Y q g dedicated development rights; protect storm drain pipes by requiring drainage easements; and seek to secure open government-maintained facilities by fee title land rights. (Implementation Measure 7-ah) • Encourage integrated pest and weed management methods which reduce or eliminate the use of pesticides and herbicides for watercourse maintenance. (Implementation Measure 7-al) The Conservation Element sets forth the following selected goals and policies. Consistency of the project with these goals and policies is discussed in the Impacts section (see page 3-127). • To employ alternative drainage system improvements which rely on increased retention capacity to lessen or eliminate the need for structural modifications to watercourses, whenever economically possible. (Goal 8-W) • To enhance opportunities for public accessibility and recreational use of creeks, streams, ' drainage channels and other drainage system improvements. (Goal 8-X) • Riparian habitat shall be protected by providing for channel cross-sections adequate to carry 100-year flows, as per policies contained in the Public Facilities/Services Element. If it is not possible to provide a channel cross section sufficient to carry the 100-year ' flow, then detention basins should be developed. (Policy 8-82) • On-site water control shall be required of major new developments so that no increase in peak flows occurs relative to the site's pre-development condition, unless the Planning Agency determines that off-site measures can be employed which are equally effective in preventing adverse downstream impacts. (Policy 8-87) Existing Levee TheJro'ect area is located within the Sacramento-San Joaquin Delta and is partially P encompassed by a levee system maintained by Reclamation District 799. These levees were built in the early 1900's to protect RD-799 properties from tidal action and from storm runoff within the Delta. The District has the responsibility for protecting approximately 3,000 acres and is operated under the provisions of Section 50000 of the Water Code of the State of California. In addition to levee maintenance, the Reclamation District also provides pumping services for the disposal of stormwaters and excess irrigation water that collects behind the levees. With a 1991- 1992 fiscal year budget of$156,000,the resources of the District are limited. Monies for general ' District maintenance and pumping are generated by assessments on lands within the District on the basis of the benefits received by each individual property owner. i 3-122 1 The average elevation of RD-799 is on the order of three feet below sea level with the landward properties, which include the project area,being surrounded by approximately six miles of levees and four miles (which includes Contra Costa Canal) of higher ground. The project area contains both the highest and lowest points within the District, those being 24 feet above sea level and ten feet below sea level respectively. The levee system of the District currently does not meet the standards of the Federal Emergency Management Agency (FEMA) in regard to either the Short Term Hazard Mitigation Plan Levee (HMP) or the Urban Standard Levee. In order for existing development to maintain eligibility for federal funds for a declared disaster, RD-799 levees must comply with the HMP design standard level. Additionally, in order to comply with the Federal Flood Insurance Program and County policy, all new development within the existing flood plain must be protected by an Urban Standard Levee or have the habitable floor of all structures at ten feet, or greater, above mean sea level. For purposes of the Federal Flood Insurance Program, FEMA will only recognize those levee systems that meet, and continue to meet, minimum design,operation, and maintenance standards that are consistent with the level of protection required. The existing levees within RD-799 generally have crest elevations and side slopes that are neither consistent with the stated standards of the District nor comply with the requirements of FEMA for an Urban Standard Levee. This existing situation could result in overtopping and/or levee breaching as a result of high tides, earthquakes, heavy rains, low tides and dry conditions, lack of maintenance and damage by vectors. Levee breaching usually occurs as a result of vector damage which occurs in non-urban areas due to poor maintenance. To date, seismic activity alone has not caused a levee breach in the Delta area. In addition, no overtopping or breaching has occurred on the Hotchkiss Tract. Additionally,encroachments onto the existing RD-799 levees by adjacent property owners make it extremely difficult for RD-799 to increase the physical proportions of the levees to increase their stability and reliability. This situation has resulted in the Hotchkiss Tract being exposed to potential flood hazards. A study was initiated in December, 1988 by. both the Bethel Island Municipal Improvement District and RD-799 to survey and enumerate levee encroachments within their respective areas of jurisdiction. The Phase I report entitled, "Encroachment Study, Bethel Island and Hotchkiss Tract", was made available in March 1990 and indicates that, at a minimum, ten private structures within RD-799 presently encroach within the future Urban Standard Levee cross section. The Phase II portion of the study, dated April 1992, identifies the specific location on the present levee where it does not meet the HMP levee height standards. It also shows the approximately 13,000 linear feet of existing levees that do not meet the height requirements of the Urban Standard Levee. It has been estimated that a cost of $2,000,000 per mile of levee would be required'to bring the existing levees in RD-799 to the FEMA Urban Standard Levee level of protection. Current estimates of the cost to upgrade the existing levee total approximately $10,000,000 (Ron Heinzen, Kleinfelder). This is a very preliminary estimate made without a detailed engineering and construction cost review. At this time due to recent state and federal budget cuts there are no funds available to assist in levee rehabilitation. All rehabilitation costs would need to come ' 3-123 i from currently assessed property owners and future development within the district. In order to arrive at a more precise cost, extensive geotechnical and civil engineering must be accomplished. It is likely that the actual cost of repairs will be much higher once more information is gathered. Reports prepared by RD-799 to date, are a start in that direction, but are primarily for identifying encroachments on the existing levees and not for performing soils borings to identify soils related problems. The time it could take to compile a report and to design corrective measures for the existing RD-799 levees, so that the report and design could be used to apply for a Conditional Letter of Map Revision (CLOMR) from.FEMA, could take on the order of 2-3 years. A formal submittal to FEMA for a CLOMR for earthen levees includes, as a minimum, the following: , • Evidence of sufficient freeboard. • Proof that all drainage structures penetrating the levee are fitted with closure devices. • Demonstration that no appreciable erosion of the embankment will occur during the 100-year flood. • Evaluation of the stability of the levee embankment and foundation. • Engineering analysis of freeboard loss due to settlement. • A levee design consistent with FEMA standards. The most extensive, costly and difficult submittals to prepare would be the evaluation of the stability of the levee embankment and foundation and evidence of sufficient freeboard. The evaluation would include extensive soils borings and other methods to determine levee stability. The urban side of the levee has been built up and many of the existing structures, improvements, residences and yards would be disturbed or removed to conduct this evaluation. Evidence of sufficient freeboard would include an identifiable source of an adequate amount of engineered fill and material. Many different sources may be necessary to gather a sufficient amount of material and fill. In a very preliminary estimate, all permits and performance of work necessary to upgrade the RD-799 levees would take on the order of seven to ten years at an estimated low cost of ' $20,000,000 (Bohley/Maley Associates, 1992). Extensive environmental review (such as environmental impact report or environmental impact statement) would also need to occur. However, simply addressing the approximately six miles of RD-799 existing levees would not i remove the project site from the flood-plain. For example, the Contra Costa Canal (which is approximately 3 miles south of the project site) does not meet FEMA standards either. The side slopes or banks of the Contra Costa Canal would likely permit the flow of floodwaters in the event the levees adjacent to the project site fail. 3-124 , i 1 The corrective measures would also have to address how to alleviate potential flooding that could occur from the south.and west as well as disposal of the 100 year rainfall event that would occur within RD-799 itself. Additionally, in order to obtain a levee certified by FEMA to allow the removal of lands from the flood hazard zone, there can be no encroachments on the levees. This would require the condemnation and removal of existing . structures and improvements on the levees within the District. At the present time, there is controversy over the"greenhouse effect," scientific theory that global warming may cause melting of the polar ice caps which could result in a rise in sea level within the next century. Some experts theorize that long tern climatological changes are due to result in substantial melting of the polar ice caps. The Bay Conservation and Development Commission (BCDC) indicates that the amount of rise may be from 2 to 8 feet in the next 100 year period. There is considerable uncertainty, however, in the magnitude and rate of this change, and simply picking a specific sea level rise in this range would be speculative. The Environmental Protection Agency (EPA) suggests a middle of the range estimate increase of four feet. The effects of such a change should be considered in flood control planning. Ground Subsidence Ground subsidence is a widespread problem throughout the Delta. Prior to construction of the existing levee system in the area, the Delta was near sea level. Today, much of the Delta is below sea level as a result of various factors including natural gas and groundwater withdrawal as well as, oxidation of organic materials in the soil (such as peat soils), wind erosion, agricultural practices, and general consolidation following the lowering of the groundwater table (USGS, 1991). The preliminary soils report for the project area indicates that there are nominal peat soils within the proposed limits of the new levees (see Section 3.8 of this EIR). However, because the project site and Hotchkiss Tract is on the edge of the delta, ground subsidence has not been as significant as in other areas of the Delta. Contra Costa County General Plan The Contra Costa County General Plan, Safety Element, sets forth the County's policies regarding flood hazards. The County's flood hazard policies most applicable to the proposed project include the following. Consistency of the project with these policies is discussed in the ' Impacts section below. • The areas designated on Figure 10-8 shall be considered inappropriate for conventional urban development due to unmitigated flood hazards as defined by FEMA. Applications for development at urban or suburban densities in areas where there is-a serious risk to life shall demonstrate appropriate solutions or be denied. (Policy 10-33) • In mainland areas along the rivers and bays affected by water backing up into the watercourse,it shall be demonstrated prior to development that adequate protection exists either through levee protection or change of elevation. (Policy 10-35) 3-125 ■ • Flood-proofing of structures shall be required in any area subject to flooding; this shall occur both adjacent to watercourses as well as in the Delta or along the waterfront. (Policy 10-38) , • Buildings in urban development near the shoreline and in flood-prone areas shall be protected from flood dangers, including consideration of rising sea levels caused by the greenhouse effect. (Policy 10-41) • Habitable areas of structures near the shore line and in 'flood-prone areas shall be cited above the highest water level expected during the life of the project, or shall be protected for the expected life of the project by levees of an adequate design. (Policy 10-42) • Right-of-way for levees protecting inland areas from tidal flooding shall be sufficiently wide on the upland side to allow for future levee widening to support additional levee height. (Policy 10-43) • In accordance with the following policies, the General Plan shall not permit a substantial non-agricultural, residential population to be subjected to increased flood hazard due to subsidence. (Policy 10-47) • Low density development of lands subject to subsidence shall take into account and fully mitigate the potential impacts of flooding based on the best currently available techniques. (Policy 10-48) • Any development approvals for areas subject to subsidence shall include conditions which account for the need to support Delta reclamation and irrigation districts, and to strengthen weak and low levees prior to development. (Policy 10-49) • In order to protect lives and property,intensive urban and suburban development shall not be permitted in reclaimed areas unless flood protection in such areas is constructed, at a minimum, to the standards of the Flood Disaster Protection Act of 1973. Levees protecting these areas shall meet the standards of the U.S. Army Corps of Engineers. ' (Policy 10-51) • The potential effects of dam or levee failure are so substantial that geologic and engineering investigation shall be warranted as a prerequisite for authorizing public and private construction of either public facilities or private development in affected areas. (Policy 10-55) • Dam and levee failure, as well as potential inundation from tsunamis and seiche, shall be a significant consideration of the appropriateness of land use proposals. (Policy 10-56) ' • Dams and levees should be designed to withstand the forces of anticipated (design) earthquakes at their locations. (Policy 10-57) r 3-126 , i Water Ouality The project site lies within the vicinity of three sloughs that are part of the Sacramento- San Joaquin Delta. Approximately 1,600 feet to the north lies Dutch Slough while one-half mile south lies Rock Slough. Sand Mound Slough parallels the eastern side of the property and is approximately 300 feet to the east. The present agricultural use of the property takes irrigation water from Dutch Slough through an existing channel traversing properties to the northwest. Dutch Slough salinities have been elevated on a number of occasions; the most recent significant event was during the 1976-77 drought. The U.S. Bureau of Reclamation and the California Department of Water Resources keep records of salinity measurements in Dutch Slough,and have documented high salinity intrusion there and else where in the Delta(Arthur Jensen, Contra Costa Water District). Stormwater and excess irrigation runoff utilizes the same channel that trends toward Dutch Slough as well as an existing channel that essentially bisects the property in an east-west direction and another channel that parallels the southerly boundary of the property. Both of the latter channels discharge into Sand Mound Slough by means of pumps that are maintained by ' RD-799. Sand Mound Slough is connected to Dutch Slough on the north but has been diked off from Rock Slough on the south in order to maintain a higher level of water quality in Rock Slough. Rock slough is the main feeder for water to the Contra Costa Canal which is the domestic water source for the Contra Costa Water District. The dike at the Sandmound/Rock Slough junction is a hydraulic structure with one-way tide gates. these gates are designed to prevent salt water intrusion from Sand Mound Slough into Rock Slough, while enabling tidal flushing of Sand Mound Slough. A number of respondents to the Notice of Preparation stated that the existing water quality of Sand Mound Slough is of concern. IMPACTS The following discussions regarding the proposed project's impacts on drainage, levees and water quality is summarized from published and unpublished sources with technical assistance from Bohley/Maley Associates. ' Drainage On-Site Impacts The proposed project would comprise approximately 1,330 residential units coupled with a golf course and water oriented amenities. The water amenities would consist of linear channels traversing the length of the project and ending in a lake. This channel/lake system, consisting of approximately 60 surface acres, would act as a retention basin that would retain peak stonmwater flows (see Figure 3.7-2). Certain areas of the golf course would also provide additional short term stormwater detention capabilities for those storms that produce runoff in excess of that able to be contained by the channels/lake. 3-127 i SgNOM CHANNELS/LAKE I , I LEVEE 0 ;f ; ; c II ,, II II '} 11 „ Q � �, �I J i z �I _ 1 oI 1 LEVEE (TYP.) 1 i 1 L3 : jI 1 1 1 l ; 0 O \ 1 p C/) 1 PUMP FORCE / 1 o I STATION ON MAIN I N 1 OUTLET STRUCTURE I 4s;:is 1 I Vis: ;:i�s•li I ------------------- ______________________________________________J ' Figure 3.7-2: CYPRESS LAKES & Proposed Drainage Facilities COUNTRY CLUB PROJECT , 37128 Source: Bohley/Maley Associates The proposed water surface of the. channels/lake would be held at approximately the elevation of the existing groundwater table. Drainage from the proposed development would be collected in underground pipes and transmitted to either the channels or the lake. De-watering structures would be constructed where the underground pipes enter either the channels or the lake in order to facilitate the cleaning of the pipes (see the Water Quality section, page 3-139). Although the proposed project would increase the area of impermeable surfaces at the project site, the project's proposed channel/lake system and a comprehensive storm drainage network would accommodate the project's increase in runoff and reduce the amount of runoff off-site. On-site storm drainage that previously was collected in ditches and flowed off-site to RD-799 pumps, would, for the most part, be collected on site and terminate in the proposed channel/lake system. This would result in an overall reduction in the amount of stormwater from the project site entering RD-799 drainage facilities. The proposed golf course would also include some storm drainage detention capacity. During storm periods when excess water accumulates in the channels and lake, waters from the lake would then be pumped to ultimate disposal in Sand Mound Slough by a pump station that would be constructed as part of the development. The pump station is intended to be built in the southeast portion of the project, and would be capable of providing the requisite protection from flooding from the 100 year storm event, and have emergency power capabilities built into the station. Impacts to Reclamation District 799 Both the peak and long term flows to the existing RD-799 pumps serving the project area would be reduced because all drainage originating within the project area levees would flow into the channel-lake system and be pumped to Sand Mound Slough by the project pump station. That portion of the rainfall that falls on the exterior slopes of the proposed levee system would continue to be directed to the existing RD-799 pumps by providing a toe ditch along the exterior of the proposed levee system. Therefore, the proposed project would result in an overall reduction .in the current drainage impacts of the site on RD-799 facilities. Relationship to the Contra Costa County General Plan The proposed project is consistent with the following County goals and policies regarding storm drainage as presented previously under Existing Setting in this section: • The proposed drainage facilities are adequate to mitigate the increased stormwater runoff that would be generated by the project and would reduce the current amount of runoff from the project site that would enter RD-799 drainage facilities. (consistent with Goal 7-T, 7-U, Policy 7-45) • The project would provide on-site water control through the construction of a lake and channels to provide on-site detention facilities. (consistent with Policy 7-46, 7-47, 8-87) 3-129 The proposed lake and channels which would act as detention facilities would be open to the public and provide multiple use. (consistent with Goal 7-Q,7-R, 8-W, 8-X; Policy 7-41, 7-42, 7-49, 7-51, 7-52: measure lag) , • The project proposes to create a maintenance district made up of the property owners to fund the maintenance of the storm drainage facilities, if the facilities are not dedicated to the County. (consistent with mitigation measures lad, lag and 7ah) • To ensure that the system would provide adequate flood control and drainage facilities, all new conveyances would meet RD-799 criteria. (consistent with mitigation measures B-25, 30 and 31) • Maintenance of the lake and channels will avoid the use of pesticides and herbicides through the implementation of alternative water quality management practices. (consistent with implementation measure 7-al) (see Water Quality discussion below) • The proposed lake and channels would be designed to accommodate the 100-years storm event within their cross-section. (consistent with Policy 8-82). Policy 7-57 is not applicable since the project site will be removed from a special flood hazard area by the construction of an internal levee system. The project would also be consistent with the County's growth management requirements that all projects finance the full cost of drainage improvements necessary to accommodate peak flows due to the project. Internal Levee The Bethel Island Planning Area is located in a designated floodplain. The County General Plan preclude substantial residential development until the project area is removed from the floodplain. The General Plan permits the construction of internal levees to accomplish this requirement. The project site is proposed to be removed from the floodplain through the ' construction of an internal levee (see Figure 3.7-3). Material for the construction of the levee would be obtained from the excavation of the interior lake and channel. Rock will not be utilized for the levee and is not required by FEMA for an urban levee such as that proposed. Rock is generally placed on the exterior slope of the water side of a levee to protect it from erosion. The proposed levee will be built on dry ground and not adjacent to any waterway. The internal levee would be constructed to FEMA standards for an Urban Standard Levee FEMA is the agency responsible for approving the proposed internal levee. FEMA approval is necessary before the site can be removed from the flood zone. Once an application for removal of the property from the flood hazard zone is received by FEMA, it is passed onto its local engineer for review. The engineer uses the standards of the U.S. Army Corps of Engineers in its review. The standards vary according to each proposed levee. In defining the applicable 3-130 BETHEL ISLAND DUTCH SLOUGH 0 4 d O 0: n y J T PROJECT SITE o HOLL=+NC CYPRESS ROAD ° TRAC_ PROJECT ! LEVEE RECLAMATION DISTR!CT NO. _Z9 BOUNDARY PROJECT LOCATION '+0 SCALE FROFFxTr LINE �posc• 3.) `HEIGHT OF LEVEE VARIES t DEFENDING ON EX.GROUND ELEVATIONS. MEN. MAX X.1717'! TYPICAL LEVEE SECTION NO SCALE Figure 3.7-3: CYPRESS LAKES & Proposed Levee System COUNTRY CLUB PROJECT Source: Bohley/Maley Associates 3-131 standards, the levee type, location and any other unique characteristics it may entail are taken into account. Generally, the standards require :the following: g 1. Freeboard - Must demonstrate adequate freeboard. 2. Closures - Evidence that demonstrates that all drainage structures that may penetrate the levee are fitted with closure devices that are structural parts of the levee during operation and designed according to sound engineering practice. 3. Erosion Protection- An engineering analysis that demonstrates that no appreciable erosion of the levee embankment can be expected during the 100-year flood. 4. Stability - An engineered analysis that evaluates the stability of the levee embankment and foundation. 5. Settlement- An engineering analysis that assesses the potential for,and magnitude of, losses of freeboard that may result from settlement of the levee and that demonstrates that the minimum required freeboard will be maintained. 6. Operations and Maintenance - A formal operations and maintenance plan. FEMA requirements for an Urban Standard Levee are also outlined in the Informational Report prepared by Bohley/Maley Associates contained in Appendix E. In order to comply with the above standards and other standards that may be applied due to the unique characteristics of the proposed internal levee, the following issues will need to be addressed with FEMA: crest top elevation and potential settlement, potential changes in groundwater flow, seismic resistance, and operations and maintenance. Crest Elevation and Potential Settlement The project proposes to construct its perimeter levee to a crest elevation of+10.2 which is the stated ultimate elevation of levees within RD-799 and is 0.2 feet higher than the FEMA required levee. This would afford a 3.2 foot freeboard from the accepted 100 year flood elevation of+7.0 feet above mean sea level. To accommodate the possible effects( of global warming and a consequent rise in the ocean levels and possible soil subsidence(settlement),the proposed perimeter levee system would be setback twenty feet from the project boundaries to allow for future construction of an additional four feet of levee height. 3-132 i The additional four feet would be achieved by adding material to the outside of the levee in sufficient quantity so that an additional four feet would be provided in levee height. No change to the interior side of the levee would be necessary to raise the levee height four feet. To raise the levee four feet would reduce the 20 feet of setback provided between the levee and - project boundary. The toe-ditch at the base of the levee to catch storm runoff would need to be relocated to the base of the raised levee. A new, levee, by virtue of its weight, may settle the underlying soils during the construction process. If settlement occurs, the levee would be raised to the required crest elevation. Consolidation to the underlying soils of the levees are expected to be on the order of 1 to 4 inches. (Kleinfelder, 1992) This consolidation would primarily occur with the lateral limits of the levees and would decrease with depth. The consolidation would occur during initial levee construction but would not have any effect on adjacent structures given the distance that existing structures are from the proposed location of the new levee. Groundwater The proposed project would have a short-term (3 to 6-months), localized impact on groundwater during excavation activities for the levee, channels and lake. The areas affected would be those immediately under and adjacent to areas where excavation would occur (internal levee,channels and lake). Subsurface waters would be dewatered during excavation of these areas. The project proposes to install a dewatering trench on the project side of the proposed levee. The depth of this trench will depend on ground surface and the depth of groundwater but is not expected to be more than 20 feet deep. Therefore, dewatering activities would only affect groundwater within the top 20 feet. Dewatering .activities for the project would not impact domestic wells around the project site because these wells are generally deeper than 20 feet. The localized dewatering activities would also not affect adjacent properties because the dewatering would occur far enough from existing residences and any draw down would only occur on the project site immediately under or adjacent to the dewatering area. To confirm that dewatering activities would not have an impact on groundwater levels in the vicinity of adjacent residences, the project includes the following monitoring program: • Groundwater monitoring wells will be installed on an approximate 200 foot spacing, as close to existing residences as possible. It is preferred that the monitoring wells be locked and located east of Sandmound Boulevard, close to the residences. • The monitoring wells will be monitoring daily for one-week prior to beginning construction to establish a trend and tidal affect on groundwater levels. • Should the monitoring wells indicate a drop in the groundwater level of 3 to 4 feet adjacent to any residence during dewatering, then water will be discharged into the dewatering ditch to stabilize the groundwater level. 3-133 _ Once dewatering activities are concluded, the groundwater would rise to natural groundwater level. The construction of the new internal levees stem would have minimal impact on Y P groundwater. Consolidation may occur under the weight of the new levee material. This consolidation would have a minimal effect on near surface groundwater transmissivity by reducing the permeability of the soils directly under the levee (to a depth of approximately 20 feet). This effect would not be considered significant and would not affect deep groundwater resources which are at a depth of approximately 200 feet (Bohley/Maley Associates, 1992). The consolidation would only occur during construction of the levee and, possibly, for one or two years thereafter. Seismic Resistance Damage to levees from earthquakes is a function of a number of interrelated factors which include the earthquake magnitude, its acceleration, the duration of shaking, local ground conditions, and the configuration and orientation of the levee itself. Section 3.8 of this EIR identifies the Maximum Probable Earthquake (MPE) and the Maximum Credible Earthquake (MCE) for the project site and states that the site is located in an area with a high potential for liquefaction. FEMA would require that the effects of seismicity on the proposed levee be a part of the data that they would review to determine compliance with their standards. To date, there has not been a circumstance where a levee breach has been caused by seismic activity alone in the surrounding delta area. To minimize potential damage to the proposed levee system from earthquake activity, construction of the levees would involve reworking and densifying the loose, clean and silty sands under the levee which are generally encountered to a depth of 10 to 15 feet. This construction technique would minimize the potential for liquefaction beneath the perimeter levee in the event of an earthquake. Maintenance For a levee to be recognized by FEMA as providing required protection to an area, the levee must be maintained in accordance with an officially adopted maintenance plan. All maintenance activities must be under the jurisdiction of a Federal or State agency, an agency created by Federal or State law, or an agency of a community participating in the Federal Flood Insurance Program that must assume ultimate responsibility for maintenance. This plan must document the formal procedure that ensures that the stability, height, and overall integrity of the levee and its associated structures and systems are maintained. At a minimum, maintenance plans shall specify the maintenance activities to be performed, the frequency of their performance, and the person by name or title responsible for their performance. The most local agency that could provide maintenance of the internal levee system would be RD-799, since it is already involved in levee maintenance and repair and is an "...agency created by ... State law...". However, since there would be maintenance requirements for other non-levee related 3-134 works (stormwater pump station,lake water quality,common area landscaping, street lights,etc.), it appears prudent to combine the project. This can be done under the auspices of one "agency" which could be a Maintenance District formed under Section 5820 of the Streets and Highways Code with boundaries the same as the project itself. The project can remain within RD-799 for internal and external/perimeter levee maintenance and repair purposes. Impact on Existing Levee and Residents The proposed project will not have an impact on the condition of the existing RD-799 levee since the project site is not located adjacent to that levee. The internal levee will remove approximately 689 acres from the approximately 3,000 acres within RD-799. If the existing levee fails, the project area will be protected by the proposed internal levee. The proposed levee and project site would provide those individuals outside of the project who would remain in the flood plain with a closer evacuation opportunity than presently exists. A failure of the existing levee which may cause major flooding is speculative and impacts of such an event cannot be fully quantified. The Informational Report contained in Appendix F, analyzes a possible scenario of a RD-799 levee breach with the proposed project levee in place. A levee failure caused by overtopping or a breach could result from a number of factors: high tide, earthquakes, heavy rains, lack of maintenance, and damage by rodents and small animals. Levee failure can also occur during low tides and dry conditions. A breach will also vary in size. A small breach caused by animals is likely to allow an insignificant amount of water through the levee. Such a breach is generally detected early and repaired in a short amount of time, minimizing the flood potential. A breach caused by heavy and consistent rainfall may result in a greater potential for flooding. However, this type of scenario is likely to permit adequate time to re-support the levee if a breach is suspected. The levee could be supported with sandbags, rip-rap or built up to add protection. A poorly maintained levee subject to heavy and consistent rainfall and/or a serious earthquake, that experiences a breach is also likely to experience erosion beginning at the breach. In this situation, the breach would be more difficult to address due to the degree and rate of erosion. ' The most common cause of a levee breach on a non-urban levee is due to lack of maintenance and damage by rodents and small animals. The existing levee is properly and regularly maintained by RD-799 and thus, is not subject to the most common cause of levee failure. A serious levee breach of the existing levee that would put the existing residents at risk of a serious flood is unlikely because the existing levee is properly maintained. Hotchkiss Tract is part of the mainland but is protected by levees on all sides, including the northerly levee along Dutch Slough, the easterly levee along Sand Mound Slough, the southerly levee along Rock Slough, the westerly levee along Little Dutch Slough and the Contra Costa Water District Canal. These levees separate Hotchkiss Tract from water in sloughs that vary from 200-300 feet in width and are not large masses of water. To date, no overtopping or breaching has occurred on Hotchkiss Tract. (Hienzen, 1992) 3-135 Presently, there is approximately 14,754 acre feet of floodwater storage volume below elevation +7 in RD-799 given its 3,000 acre extent and an average elevation of 3 feet below mean sea level. With the project in place, there would be a reduction-of.approximately 3,382 acre feet of volume. As discussed in the Informational Report in Appendix E, in the event of a levee breach or failure of the existing RD-799 levee directly across from the project site along Sandmound Boulevard, the proposed project and levee system would alter the direction of flow of flood waters and the amount of time necessary to flood the area within RD-799. It is important to note that flood waters would gravitate to the lowest point in the area which is along Sandmound Boulevard, producing a flood depth of 5 feet, if mean sea level is assumed to be the equilibrium point between tidal cycles (Bohley/Maley Associates, 1992). The flood depth would not increase as a result of the project. According to the Informational Report in Appendix E, removal of the project site from the floodplain would increase the rate by which the rest of the floodplain would be flooded in the event of a levee breach. This is because removal of the project site would reduce the amount of water necessary to flood the remaining portion of the floodplain. In an attempt to quantify this reduction in time, the Information Report calculated the time it would take to flood RD-799 with and without the project. This analysis indicates that the initial flooding of areas between - -5 and -7 feet would occur 64% faster with the project. The project would have less of an impact on the rate at which those areas between 0 and -5 feet would flood (37% faster). Areas above 0 feet and less than +7 feet would flood only 18% faster with the project. Another way to look at the project's impact is that given the breach parameters modeled, it would take 1.4 days to flood RD-799 from elevation -7 to elevation -5 under current conditions. With the project, this time frame would be reduced to 0.9 days (64% reduction). The resultant maximum depth would be 2 feet. Extending the analogy of flooding to mean sea level (0 feet), the representative times are 4.4 days without the project and 3.2 days with the project (37% reduction) with a resultant maximum depth of seven feet. (Bohley/Maley Associates) The project levee would parallel the existing substandard RD-799 levee for approximately 2,500 feet along Sand Mound Slough. In the event of a levee failure along Sand Mound Slough, , the lands in,RD-799 would act as 'overflow land" for flood waters which would rise and fall with the corresponding tidal cycles. Flood waters would not stop flowing if they reached the project levee. Instead, the project levee would divert waters heading westerly into a northerly and southerly direction. The diverted waters would then reach the north and south ends of the project levee and spread out into the remaining areas of RD-799. The flow rate of the water is not easily quantifiable, since it is dependent on many variables such as the degree of the levee breach or overtopping, the possibility of erosion, the level of wave action, and the height of the tide. However, the Informational Report in Appendix E attempts to quantify the flow rate and depth assuming certain characteristics of the levee breach. Levee overtopping and breaching could be effectively eliminated if RD-799 upgrades their levees to a full Urban Standard Levee configuration. (Bohley/Maley Associates, 1992) 3-136 In the event of a major levee failure and flooding creating the need for evacuation, residents along Sandmound Blvd. are currently provided with only one reasonable egress route (Sandmound Boulevard) for evacuation, provided it is not inundated. The project, with its proposed improvements to Cypress Road would provide another more direct and faster route for evacuation. The project would provide an immediately available (within 300 feet) location to escape from a levee breach. In the event of a major flood, the project would provide a fire station, many locations for possible heliports, potable water, and substantial staging areas (golf course and parks). . The project applicant proposes the evacuation routes on Figure 3.7-4 for residents in areas adjacent to the proposed project. The project applicant proposes to develop ' a more detailed emergency evacuation plan in cooperation with RD-799 for residents in areas adjacent to the proposed project. The evacuation plan will include, at a minimum: • Criteria for determining when an emergency exists. • Methods for notifying and evacuating residents. • Identification of agencies and individuals responsible for emergency response and public evacuation. • Plans for returning evacuees to their homes after the emergency has passed. Alternative Levee Configurations/Improvements The Reclamation District and others have proposed different levee configuration and levee improvement alternatives to remove project site and Hotchkiss Tract from the 100 year flood plain. Three of these alternatives are outlined below. Fix the entire existing levee: This alternative would take the entire district out of the 100 year flood plain; however, the financial burden, the construction impacts on existing residences and the inability to upgrade the levee in a reasonable period of time makes this option infeasible. (also discussed on page 3-123) �f Quadrant system: This alternative includes dividing the district into four sections incorporating the new internal levees with the existing levees. The reason this alternative has been rejected is similar to the proposal for fixing the entire existing levee. The quadrant that ' includes the Cypress Lakes project would require improvements to the Sandmound levee. This particular portion of the levee is urbanized and has many encroachments. This levee portion would require extensive stability work, width and height improvements. This proposal would not be feasible from a timing, construction and financial perspective. Alter the internal levee layout: This alternative would involve pulling the new internal levee near Sandmound to the west further from the existing levee. This would not change the affects of the internal levee system in regards to flood water diversion. If a portion of the Sandmound levee broke, the effect of the new internal levee system 200+/- feet away would not be any less of an impact if moved further away. Breaks usually begin with small leaks eroding into larger holes. A break is highly unlikely to become bigger than 50 feet. This size of breach would loose energy very quickly. 3-137 III - r 0Ai 01 2t01, 4 44 �'It1►r��'rr �'i � r":II1t111111rIt y�� MWIrlIN MIN no M WIN ME no IF0 to 04, Ar" till ills DO IF is lilt I Figure 3-7-4: Proposed Emergency Evacuation Routes CYPRESS.LAKES & COUNTRY CLUB PROJECT 3-139 Source: Bohley/Maley Associates --J Relationship To Contra Costa County General Plan The Flood Hazard Element of the Contra Costa County General Plan sets forth many policies which are applicable to the proposed project. These policies primarily address the need for projects to adequately demonstrate that the existing flood hazard within the project area can be mitigated to an acceptable level. The proposed project is consistent with these policies for the following reasons: • The project would include a internal levee around the entire project site which would meet FEMA standards enabling the site to be removed from the Flood Hazard area. • The proposed levee would be constructed in such a way as to allow for increasing its height if necessary. • The Delta area is not subject to tsunami (wind generated) and seiche (earthquake generated)waves. Tsunami waves entering into San Francisco Bay are attenuated by 50% at the head of the Carquinez Strait. Seiches occur in narrow deep bodies of still water which are not present in the Delta. Therefore, the possibility of tsunami and seiche waves are remote. Water Ouality The project proposes to construct a series of interconnecting channels and a lake. All storm drainage facilities within the project would terminate at either one of the channels or the lake itself. Because of the elevations of the site, the proposed underground storm drain system would be a "wet" system meaning that water would be standing in most of the storm drain pipes at all times. In order to allow for the periodic cleaning of the storm drain pipes, the project proposes to construct de-watering structures at the points where the pipes enter either the channels or the lake. These de-watering structures consist of a slide gate that can be lowered, and a chamber upstream of the gate which can be used as a sump to pump water from the storm drain pipes. As each storm drain pipe system is de-watered, the pipes themselves can be flushed with the flushing water either being discharged into the channel/lake system or discharged into a water truck to be disposed of off site. Therefore, the proposed storm drainage system would have minimal impacts on groundwater quality. The proposed lake and channels would be filled with existing near-surface groundwater. As discussed previously, excavation for the lake and channels would require dewatering of the near-surface groundwater. Upon completion of excavation activities, dewatering would stop and the lake and channels would fill up as the near-surface groundwater migrated back into the project site. No additional pumping of groundwater is proposed to maintain the water level of the lake and channels. Excess water, as a result of stormwater runoff into the lake and channels, would be pumped off the project site into Sand Mound Slough. 3-139 The existing drainage ditch traversing the site would no longer drain to the RD-799 pump station that pumps drainage waters to Sand Mound Slough. The ditch would be integrated into the lake/channel system which would result in a reduction of silts and agricultural contaminants that currently are pumped to Sand Mound Slough. The obstruction to the ditch by construction of the levee would occur in the first phase of construction with the levee slopes being hydro seeded to prevent erosion. All runoff within the levees would be retained on site using the lake/channels as necessary for retention. The project also proposes a closed water circulation plan. Water circulation would be achieved by a system utilizing a pump located in the stormwater pump station. This pump would continuously circulate water to the furthest extremities of each of the channels, and some of the underground storm drains, to the extent that all the water within the channel/lake system would be pumped at least once every two weeks during the non-rainfall months (May to October). During storm periods, the main stormwater pumps would be used to discharge excess stormwater into Sand Mound Slough through a force main and outlet structure located on the bank of the slough. Increased surface runoff from the new impervious surfaces may have impacts on the water quality of the channels and lake and ultimately the Delta. Urban runoff can contain substantial quantities of pollutants such as organic pesticides, heavy metals, nutrients, petroleum products, and suspended solids. Among the sources of these contaminants are street debris, chemicals in �. general use, airborne urban particulate matter, and various synthetic materials. Another impact to the proposed channel/lake system is the growth of aquatic plants. Some of the more noxious plants are widgeon grass and the water hyacinth which, if left to grow unrestricted, could produce substantial negative aesthetic impacts, as well as clog pumps. To address potential contamination and aquatic plant growth in the lake and channels, the project plans include a water quality management plan which includes the following components: • The side slopes of the lake will be 3 or 4 to 1, to limit plant growth, but shallow enough to avoid slope failure. • The lake depth will be approximately 17 feet with a plateau in the middle of the lake to provide an area for plants conducive to filtering metals and other unwanted materials to grow lodes densa, Totamoatas pectinatus . • Pods of another plant species (Ceratonhyllum denersum), will be suspended throughout the lake and channels to further filter the water and improve water quality. The pods would be removed and replaced no less than two times a year. • To control unwanted aquatic plant growth and algae a system of hydraulic flushing and aeration will be utilized. Herbicides and pesticides would not be utilized. 3-140 • A program to identify unwanted macrophytes early and control them will be implemented. • Mosquito populations will be controlled by planting fish in the lakes rather than the application of chemicals. • Floating petroleum products will be removed through the utilization of mechanical built-in skimmers. Figure 3.7-5 depicts the typical cross-section of the lake showing the proposed plateau and pods. The proposed golf course could result in a significant source of undesirable nutrients and biocides which could enter the lake and channel systems through the project's drainage system. To address this potential impact on lake and channel water quality the project golf course maintenance criteria which includes the following: • Irrigation management strategies to minimize runoff from the golf course. • Use of slow-release fertilizers which are less likely to enter ground and surface water. • Pesticide and herbicide use shall only be used as part of an integrated pest management or vegetation manipulation plan. • Irrigation shall be limited after application of fertilizers and biocides to reduce leaching of chemicals into groundwater or transport in runoff to surface water bodies. • Avoid the application of fertilizers and biocides before the onset of the rainy season to reduce the risk of leaching. Implementation of a comprehensive golf course and the lake water quality management plans as described above would mitigate potential adverse contamination and aquatic plant growth in the lake and channels. The project's stormwater drainage plan also includes the pumping of excess runoff off the project site and into Sand Mound Slough. As described above, the water quality of the lake and channels would be monitored and maintained to acceptable levels. Pumping of this water into Sand Mound Slough would provide a beneficial impact on the water quality of Sand Mound Slough as long as the water quality of the lake and channels is properly maintained. To ensure that stormwater discharged from the project site into Sand Mound Slough is of acceptable quality, the project would be required to meet the requirements of the County's National Pollutant Discharge Elimination System (NPDES). Under the requirements of the NPDES permit requirements, the project would be required to incorporate measures to improve stormwater quality such as the proposed golf course maintenance and water quality plans. 3-141 Z " z Q LLJ X W 2 �i m O U O CYPRESS LAKES & Figure 3.7-5: COUNTRY CLUB Typical Lake Crass—Section PROJECT — Water Quality Control Source: Chartered Land and Cattle 3-142 In addition, the County would periodically monitor stormwater discharge for pollutant levels. If pollutant levels exceed established criteria the County would report the violations to the State Water Quality Control Board who could impose additional measures to improve the quality of stormwater discharges. MITIGATION MEASURES Drainage The proposed project includes numerous measures to mitigate the project's drainage impacts, such as: 3.7-1 On-site storm drainage facilities (lake, channels and golf course detention facilities) shall be constructed to both protect property and to provide for public safety by accommodating the 100 year storm event. 3.7-2 Dewatering structures (discussed in the Water Quality section)shall be constructed at those points where underground storm drainage pipes enter the channel/lake system in order to facilitate the periodic flushing and cleaning of the underground pipes. 3.7-3 Drainage ditches shall be constructed along the exterior toe of the proposed levee system to catch that runoff from the exterior slope of the levees. The drainage ditches shall discharge into existing drainage ditches along the perimeter of the project. 3.7-4 Maintenance of on-site storm drainage improvements within the public right-of- way, or in suitable easements, shall be performed by the County of Contra Costa. Stormwater pump station maintenance shall be performed by the public entity selected to be responsible for the operation and maintenance of the perimeter levee. Implementation of these mitigation measures will reduce the project's impact to a less- than-significant level. No additional mitigation measures are necessary. Levees The following measures are proposed as part of the project to reduce potential impacts associated with construction of the internal levee system and therefore are the responsibility of the project applicant. All plans and activities related to construction and maintenance of the internal levee system should be reviewed and approved by FEMA and RD-799: 3.7-5 The design of the project levee shall be in accordance with the standards and requirements of the Federal Emergency Management Agency for an Urban 3-143 i Standard Levee. Provisions shall be designed into the project levee to allow for a future increase in height of four feet to allow for the "greenhouse effect". During the design of the project levee, the crest elevation shall'be increased by an amount equivalent to projected long term settlement. 3.7-6 The side slopes of the project levee shall be planted and irrigated to reduce erosion, and to provide dust control, in accordance with the project's landscape guidelines.and the guidelines of the public agency responsible for maintenance of the levee. 3.7-7. Adequate easements shall be granted to the maintaining authority in order to provide for maintenance and upgrading of the levee, and to prohibit encroachments onto the levee. 3.7-8 To minimize the risk of liquefaction beneath the perimeter levees, the loose clean and silty sand of depths of 10 to 15 feet shall be reworked and densified. Deep dynamic compaction and/or over'excavation and compaction of soils shall be utilized to densify the soils. The following mitigation measures are proposed in addition to those proposed as apart of the project to further reduce any potential impact associated with construction of the internal levee system to a less-than-significant level: 3.7-9 The levee landscape guidelines should be finalized once the public agency responsible for maintaining the levees is determined. The levee landscape guidelines should then be submitted to the public agency responsible for maintenance of the levees for review and approval prior to installation of any landscaping on the levees (same as mitigation measure 3.5-7) (Responsibility: Project Applicant) 3.7-10 A detailed emergency evacuation plan based on theproject's pro osed emergency Y evacuation plan shall be prepared in cooperation with RD-799 and . the governmental agency that ultimately accepts the internal levee system prior to approval of the project's final subdivision map. The evacuation plan shall include at a minimum the following measures: • Criteria for determining when a emergency exists • Methods for notifying and evacuating area residents • Identification of agencies and individuals responsible for emergency response and public evacuation 3-144 i • Plans for returning evacuees to their homes after an emergency has passed. (Responsibility: Project Applicant) The proposed project includes a groundwater monitoring plan to monitor groundwater levels near adjacent residences during project construction to avoid potential impacts to existing residences. The following mitigation measure is proposed to ensure implementation of the proposed monitoring plans: 3.7-11 The proposed groundwater monitoring plan shall be made a condition of project approval. A final groundwater monitoring plan shall be submitted for review and approval by the County prior to filing a final subdivision map. (Responsibility: Project Applicant/Contra Costa County) The following mitigation measure is proposed to ensure a continued source of funding to RD-799 from the project site for continued maintenance of the existing levee system which provides a fist line of defense against flooding. 3.7-12 The project site shall continue to be a part of RD-799 and shall be prohibited from seceding from this district, even if removed from the flood hazard zone by the proposed internal levee system, to provide the district with a continued long-term source of funding for maintenance of the existing RD-799 levee system. (Responsibility: Contra Costa County/Project Applicant) Implementation of these mitigation measures will reduce potential impacts of construction of the project levee system to a less-than-significant level. Water Quality The proposed project includes measures to ensure adequate water quality is maintained in the project lake and channels. The measures include a water quality management plan for the lake and channels and maintenance criteria for the golf course. The following mitigation measures are proposed in addition to the measures proposed as part of the project to ensure adequate water quality in the lake and channels: 3.7-13 A final maintenance plan for the Golf Course shall be submitted for review and approval by the County, prior to filing a final subdivision map. The final maintenance plan shall build on the maintenance criteria established in the project plans and identify standard maintenance and management practices to be carried out on the Golf Course. Specific maintenance procedures shall be identified regarding the use of pesticides, herbicides, and fertilizers. An emphasis of the maintenance plan should be to reduce potential leaching into local groundwater resources. The maintenance and management plan shall also outline specific 3-145 irrigation practices designed to reduce water consumption. (Responsibility: Project Applicant) 3.7-14 An informational packet shall be distributed to all project residents to educate them on the use and disposal of undesirable materials such as motor oil, paints, garden pesticides and other household products. The informational packet should be distributed to project residents upon purchase of each house. (Responsibility: Project Applicant) 3.7-15 A street sweeping program shall be provided to reduce urban pollutant run off into the proposed lake and channels. The street sweeping may be provided by the County through its existing street sweeping program. If this is not feasible, alternative measures could include funding of the street sweeping program by the homeowner's association. (Responsibility: Contra Costa.County/Homeowners Association) 3.7-16 A final channel-lake operation and maintenance plan shall be submitted for review and approval prior to filing a final subdivision map. The plan shall be based on the applicant's proposed lake-channel management plans utilizing plants,flushing, aeration and other techniques to maintain water quality without chemicals. (Responsibility: Project Applicant) 3.7-17 The project shall comply with all the requirements of the County's NPDES permit requirements. The project applicant shall provide the County with the appropriate documentation regarding compliance with NPDES requirements prior to the issuance of grading permits for the project. (Responsibility: Project Applicant) 3-146 3.8 GEOLOGY, SEISMICITY AND SOILS The following information regarding local geology, seismicity and soils is summarized from several published and unpublished sources including: the Contra Costa County General Plan, 1990-2005, January 1991; the Draft and Final Environmental Impact Report, Bethel Island Area Specific Plan, October 1989 and January 1990; the Geotechnical Investigation Report, Phase I r Study Proposed Bethel Island Area Proiect, December, 22, 1988 prepared by Kleinfelder, Inc.; and the Report Evaluation of Proposed Levees Bordering - Cypress Lakes Proiect, August, 1992 prepared by Kleinfelder, Inc. All of these reports are available for review at the Contra Costa County Community Development Department. EXISTING SETTING Geology The project site is located within the Great Valley Geomorphic Province of California, in a region known as the Delta where the Sacramento and San Joaquin Rivers converge. This province consists of a thick layer of sedimentary rocks ranging in age from the Jurassic period to recent. The exact thickness of the sedimentary deposits is unknown. Deposits of marine sediments are known to extend 13,000 feet below ground level according to natural gas wells drilled in the nearby Dutch Slough gas field. These deposits consist of consolidated, regularly bedded faulted and folded layers of sandstone, siltstone, shale mudstone, and conglomerate. The structural features in these rocks form traps where natural gas and oil are found. Structurally the Great Valley of California, is a large, elongated, northwest trending asymmetric trough. This trough has a long, stable eastern shelf, which is supported by the buried west-dipping slope of the Sierra Nevada mountain range. The valley's western flank is formed by the steep upturned edges of the basin sediments. The sediments that form the thick valley floor were largely derived by erosion of land areas located to the east of the valley. For the major portion of the Jurassic and Cretaceous periods;the major sediment source was most likely the Batholiths of the Klammath Mountains and the Sierra Nevada mountains. During the Eocene time, the source of rocks are thought to be the highlands on all sides of the valley. The project site is located near the border of the Great Valle and Coast Range P J Y Geomorphic Provinces. During Pleistocene time the delta area is thought to have undergone several depositional and erosional cycles that were brought about by dramatic changes in climate. Sea level changes and glaciation have resulted in the deposition of peat and mud layers and subsequent erosion by running water and wind. However, since late Pliocene time (approximately 2 million year ago), the Sacramento-San Joaquin Valley has been above sea level and consequently recent geologic deposits are mostly nonmanne. These deposits typically consist of unconsolidated sand, silt clay and peat. The geology of the project site has been mapped by Nilsen (1975) and by Nilsen and Sims (1975), The surficial geology has also been mapped by Atwater (1982) and is presented in Figure 3.8-1. 3-147 Franks Tract yaw.g.......w.. \ ' Franks Tract t . Harbor . �-. Bethel t Island ,\ :o .\.\ �. .po ' •oa Island \}e s*o•� \ a Galt-ay Road I •' Cattagy /' •`• •�:::Sandy La. 1I Ranch La. i .•,'�� •,•�.-.Sieh Dacca Slough r+�.?�� 'r�op• /,j •• I Dutch Slough Road s,, ....••. Rae Rad• \I A nJ . th 3.1 Holland Tract Project Site :a r Peat and Mud of Tidal® Alluvium of Marsh Q Eolian Deposilt Wetlands and Crock(Qymc) (QmZe) Waterways(Qpm) r Location Generally ——— Location May Err Accurate Within 500' By Atone Than 500' Atwater(198':) CYPRESS LAKES & Figure 3.8-1: COUNTRY CLUB PROJECT Surficial Geology of the Project Area 3-148 j The surficial geology of the project site consists primarily of eolian deposits of wind blown sand of the Upper Modesto Formation which form a large dune field fanning eastward and southeastward from Antioch. The age of the upper Modesto Dune Sands is between 40,000 and 100,000 years. On the project site, these sands overlie alluvium of Marsh Creek that in turn overlie San Joaquin River alluvium ranging in age from 38,000 to 46,000 years. Alluvial deposits of silty clay underlie the Hotchkiss Tract and Jersey Island at 50 to 90 feet below the present ground surface. These deposits were probably formed due to a sea level change during a lesser interglacial period about 38,000 to 46,000 years ago (Atwater, 1982). The eolian sand is generally fine grained with discontinuous silty sand strata or lenses. The sand exhibits a moderate amount of cementation in outcrops located on the western and northeastern portion of the project site. However, borehole logs indicate that the sand within 15 feet of the surface is loose to medium dense; below that depth the sand is dense. Marsh Creek alluvial deposits, consisting of silty clay and clayey silt generally 7 to 10 feet thick, were encountered in the southwestern and south central portions of the site. Seismicity TheJro'ect site is located in an area of moderate seismicity and is adjacent to an area of P high seismicity in the San Francisco Bay Area (see Figure 3.8-2). Several major faults with historic or Quaternary (last two million years) activity are present in the region to the west of the project area. Table 3.8-1 presents a summary of these faults and their respective distance from the project site. Also shown are the Maximum Credible Earthquake (MCE) and Maximum Probable Earthquake (MPE) for these faults. The MCE is the largest earthquake that may be reasonably anticipated to occur on a fault based on the history of movements and tectonic environment of the fault. The MPE is the largest earthquake that may reasonably be anticipated to occur on a fault during a one-hundred year period. The MPE is determined from historic and geologically determined seismicity and its value is subject to interpretation by geologists and seismologists. TheJro'ect site and the San Francisco Bay Area is seismically dominated by the presence P of the San Andreas Fault system. The San Andreas Fault system is the boundary between the northward moving Pacific Plate (west of the fault) and the southward moving North American Plate (east of the fault). In the Bay Area this movement is distributed across a complex system of strike-slip, right-lateral parallel and subparallel faults which include the San Andreas, Hayward, Calaveras, Concord and San Gregorio faults among others. Figure 3.8-2 depicts the location of these faults in relation to the project site. Historically, the-Bay Area, including the project site and vicinity, has been subject to intense seismic activity. Several historic earthquakes have been associated with the northern segment of the San Andreas Fault. Of these, the April 18, 1906 San Francisco earthquake, with an estimated Richter magnitude of 8.3 and the October 17, 1989 Loma Prieta earthquake, which registered 7.1 on the Richter Scale, are the most famous. 3-149 o N o o ` c. ,• V E a N d O V •• :• �v tK' \ t co r ! j t Y` � \� �,! �f` � ♦' '��\\yyrs � •� r . �t ...r•,% t, »moi �v OV �C � ti S � � �1 .+.»�yi/' f• 3 J it S �� �: �� m eni i i '}�b • off° f '{ 40 I'_��. /�„ •C ' i o� �d O ♦a•• •�i ! /moi�t �r r� � '�` t j � � ✓. ice.+m .�+•Z• a !nrVA O R r ►«• f �6. 10 G � � Vn 3,150 TABLE 3.8-1 ACTIVE FAULT DATA MCE Maximum Maximum Approximate ' Approximate Credible Probable Site Bedrock Fault Distance (mlles) Magnitude Macnitude Acceleration' Antioch 8 6.6 5.5 0.05 - 0.40g Calaveras 24 7.25 6.5 0.05 - 0.30g Concord 16 6.25 5.5 0.10 - 0.30g Greenville 16 6.25 5.5 0.11 - 0.25g Hayward 34 7.25 6.75 0.05 - 0.20g San Andreas 52 8.5 8.25 0.05 - 0.15g ' Actual surface accelerations would vary from bedrock values shown, however, evaluation of this value and the soil-structure interactions is a complex matter involving detailed engineering and geologic analysis. Source: Draft EIR, Bethel Island Area Specific Plan, page V-4, and Geotechnical Investigation Report, page 6. A number of high magnitude earthquakes have originated in east Contra Costa County' or adjacent portions of Solano County. Among the largest of these were a pair of earthquakes that occurred on April 19 and 21, 1892. Using Modified Mercalli intensity data, the epicentral area of these seismic events appear to be in the vicinity of Winters and Dixon. Although no surface fault rupture was confirmed during these earthquakes, the epicentral area approximately coincides with the mapped tract of the Midland fault. It is a generally north-south trending bedrock fault that bisects the eastern portions of Solano and Contra Costa County. Although the Midland fault is not considered active by either the U.S.Geological Survey or California Division of Mines and Geology, it is clear that relatively high magnitude earthquakes have originated in the East County area. The Hayward Fault lies approximately 34 miles west -of the project site and extends northwestward from the cities of Warm Springs on the south to San Pablo on the north. Tectonic slippage or seismic creep has been measured to be 0.2 to 0.76 cm/year along this fault (Herd, 1978). The MCE for this fault is 7.5. The northern portion of the Calaveras Fault lies approximately 24 miles west of the site. The Calaveras Fault is thought to have caused the July 2, 1861 earthquake which reportedly generated high intensity ground shaking in the San Ramon Valley. Continued signs of activity along this fault have been confirmed by the Coyote Creek earthquake of 1979 along with seismic creep which ranges from 0.2 to 0.7 cm/year (Herd, 1978). 3-151 The Concord Fault extends approximately 15 miles south of Suisun Bay, It is a predominately right-lateral strike-slip fault which has a recent history of seismic activity. The Concord Fault expresses itself north of Suisun Bay as the Green Valley Fault, although the two faults may not be related. The Antioch Fault is thought to have been the likely source of small to moderate earthquakes that occurred in 1866 and for the Collinsville earthquake of May 19, 1889, which was apparently felt throughout most of central California. An earthquake swarm which occurred southwest of Antioch was recorded in 1965, centered approximately 9 miles west of the project site. No mapped active faults traverse the project site. However, it remains likely that the project site will be subject to a high degree of ground shaking from earthquakes on the Antioch, as well as other active faults in the Bay Area. Soils Composition DELTA AREA The Sacramento/San Joaquin Delta area is located in an area generally classified as "Tidal q g Y Flat-Delta Marsh Lowlands." Soils in these areas are generally highly expansive, very highly corrosive, and moderately to slowly permeable. With regard to agricultural capability, soils in the Delta lowlands are chiefly Class III and. IV (non-primeagricultural soils). According to the Soil Survey of Contra Costa County(1977),large areas of Class III soils are found on the islands and areas surrounding the San Joaquin-Sacramento Delta, and in and around the community of Oakley. The Class III soils found in these areas are from the Kingile and Rindge Associations which are described as "very poorly drained organic soils" used primarily for irrigated field crops such as corn, milo, asparagus, tomatoes and pasture. Class IV soils are also mapped in the Delta lowlands. These soils tend to be poorly drained and have excessive salts. Their agricultural use is limited irrigated pasture and dry farming of grains such as barley. PROJECT SITE AND VICINITY Figure 3.8-3 maps the soils identified on the project site and vicinity by Kleinfelder, Inc., the applicant's geotechnical consultant. Soils in the project area consist of silty sand and sand, silty clay, nominal amounts of organic clay or silt and nominal amounts of peat. These are generally moderately permeable, and have a low expansion potential. 3-152 Franks Tract Ilk • -�\ fdPh I a Franks Tract tRd `✓ Rd Ph I Phi • o° Rd ~r .I P r Rd Rh S. Ph S. P• d Rd R � Ad LAW I Pe �\ RhRd ��•� so Ph .�.. Bethel nd s• ' `- s. o Pe ie Ph RhPh - V Ph P.ik Jersey •�.� Is �� V Rh S•Sell P ' so Ph S CottageS S• _ Ile L So 4- Ph •i ' °• P Fe 1 Fe1 Ph Fe ( �e Fe• -�/� 1�e J outcb Slours ,r`Oe S•1. . So • P• i P;%., P.I E. 1 PhPh 1 I ® Ph S 'so ll P• S. • Sa E. E• •�� Legend Ph t Ph _ P• D&C Delhi Sand. 2-9% Slooes Rh D.0 ' V ; Ea Egbert Mucky Clay Loam I Mb ' E. Fe Fiuvaouants S. \ Kb Kinpile Muck Ph Mb Marcuse Clay �,P• =1 Ph•Q•' ` Ph Fe P• Plo.r Loamy Sand � Mb :e W Ph Pber Fine Sandy Loam Rd Rindpe Muck ��.. Dec E. C7.nu Rad Ea Rh Ryde SW Loam Sit Sacramento Clay Ph Pe J;� Sb Sacramento Clay.AlkaY `\ 3W Se Shia Muck We Weblle Muck Holland Tract �,� P• o.c sb fe W W.ter y \ 1 \\\ Project Site Boundary p• Ea Se • Mb V... Ph P P. I Fe Figure 3.8-3: CYPRESS LAKES & Map of Soils in Project Area COUNTRY CLUB PROJECT 3-153 Sampling and laboratory testing of soils on the project site was performed for the proposed project by Kleinfelder, Inc. in September, 1988 and April, 1992. Soil sampling consisted of drilling 28 test borings. Laboratory testing was performed to evaluate the gradation and strength characteristics of the subsurface soils. In addition, cone penetration testing was performed to provide additional information regarding subsurface soils. Four piezometers were also installed on the site to measure and monitor groundwater levels. The soil sampling and laboratory testing indicates that soils consist chiefly of loose to dense sands and silty sands to a depth of 120 feet. Sands in the upper 10 to 15 feet are generally loose to medium dense; and below this depth they are dense. The near surface soils consist of a thin organic topsoil layer, 1 to 2 feet thick; underlain by a 1 to 2 foot thick layer of sandy clay and clayey sand. A thicker sandy and silty sand layer was encountered in the borings south of the dirt portion of Cypress Road. According to the cone penetrometer testing, some organic material (peat) may be present at various locations on the project site. Underlying the sandy and silty clay layer are fine grained, loose to medium dense sands and silty sands. A light brown sandy and silty clay layer was encountered at a depth of 48 to 56 feet below the existing ground surface in most borings. This clay layer is very stiff to hard and ranges from 8 to 20 feet in thickness. Underlying the clay layer are dense sands and silty sands containing thin discontinuous hard silt and clay layers to a depth of 128.5 feet. The Kleinfelder report entitled, Report Evaluation of Proposed Levees is available for review at the Contra Costa County Community Development Department. The report provides detailed information regarding the soil profile under the proposed perimeter levee system. Groundwater The boring logs and results of the cone penetrometer results are contained in the Geotechnical Investigation Report and the Evaluation of Proposed Levees prepared for the project which are available for review at the Contra Costa County Community Development Department. Table 3.8-2 summarizes the results of the piezometer monitoring program. Liquefaction Potential _ The project site is located in an area designated by the Contra Costa County General Plan as having"Generally High" liquefaction potential. Liquefaction is the transformation from a solid to a liquid state as a result of increased pore pressure and reduced effective stress. The result is a condition similar to quicksand where the liquified layer is thick and near the surface structures may gradually sink downward and tilt. 3-154 TABLE 3.8-2 RESULTS OF PIEZOMETER (GROUNDWATER LEVEL) TESTING Approximate Static Piezometer# Date Read Water Elevation (in feet) P-1 9-29-88 -10.5 P-1 11-9-88 -11.5 P-2 9-29-88 -4.8 P-2 11-9-88 -5.2 �. P-3 9-29-88 -4.6 P-3 11-9-88 -5.0 P-4 10-5-88 -6.8 P-4 11-9-88 -7.0 Source: Geotechnical Investigation Report, December 22, 1988. The liquefaction potential of the project site was assessed by Kleinfelder, Inc., based on the soil borings and other tests conducted for the Phase I geotechnical analysis. The analysis indicates that a magnitude 6.75 earthquake creating peak ground acceleration of 0.2g or greater would probably result in liquefaction of the near surface sands and silty sands over most of the site, unless proper mitigation measures are implemented. Of greatest concern in the project area is damage to delta levees as a result of liquefaction. Siesmic activity alone has never caused a levee failure in this area (Kleinfelder). Local Planning Policies and Regulations Contra Costa County General Plan The Contra Costa County General Plan contains Goals, Policies and Implementation Measures regarding Seismic Hazards (Safety Element) and Soil Resources (Conservation Element). The following policies and implementation measures are taken from the County General Plan and specifically pertain to the proposed project. Project consistency with these policies and implementation measures is discussed under "Impacts". SEISMIC POLICIES • Significant land use decisions (General Plan amendment, rezoning, etc.) shall be based on a thorough evaluation of geologic-seismic and soils conditions and risk. (Policy 10-2) • Because the region is seismically active, structures for human occupancy shall be designed to perform satisfactorily under earthquake conditions. (Policy 10-3) 3-155 • In areas susceptible to high damage from ground shaking, geologic-seismic and soils • studies shall be required prior to the authorization of major land developments and significant structures (public or private). (Policy 10-9) • This General Plan shall discourage urban or suburban development in areas susceptible to high liquefaction dangers and where appropriate subject to the policies in 10-20 below, unless satisfactory mitigation measures can be provided, while recognizing that there are low intensity uses such as water-related recreation and agricultural uses that are appropriate in such areas. (Policy 10-18) • Any structures permitted in areas of high liquefaction danger shall be sited, designed and constructed to minimize the dangers from damage due to earthquake-induced liquefaction. (Policy 10-20) • Approvals to allow the construction of public and private development projects in areas of high liquefaction potential shall be contingent on geologic and engineering studies which define and delineate potentially hazardous geologic and/or soils conditions, recommend means of mitigating these adverse conditions; and proper implementation of the mitigation measures. (Policy 10-21) • The areas (100 year Flood Hazard Areas) designated on Figure 10-8 (See County General Plan, . 10-51) shall be considered inappropriate for conventional urban development due P P to unmitigated flood hazards as defined by FEMA. Applications for development at urban or suburban densities in areas where there is a serious risk to life, shall demonstrate appropriate solutions or be denied. (Policy 10-33) SOIL RESOURCE POLICIES • Erosion control procedures shall be established and enforced for all private and public construction and grading projects. (Policy 8-63) • Lands having a high erosion potential as identified in the Soil Conservation Service's Soil Survey of Contra Costa County shall require adequate erosion control methods for agricultural and other uses. (Policy 8-68) IMPACTS Grading The grading concept for the project is to provide a balance of cut and fill on-site. No export or import of material is proposed. The existing areas of higher ground and the existing main drainage ditch will be incorporated as features on the grading plan. The "pointed" high areas will be graded to achieve a more smooth surface to accommodate street slopes and building pads. The existing 24 foot wide drainage ditch would be widened to a minimum 100 feet and 3-156 1 enhanced. The maximum cut proposed is a depth of approximately 17 feet in the lake and channel area. The maximum fill proposed is an approximate height of 17 feet above existing ground and generally occurs at the levees. The initial grading operation will involve the 1 excavation of the lake and channels and the construction of the project levee. (Bohley, 1992) Additional excavation may be necessary under the proposed levee system to rework and densify these soils to accommodate construction of the levees. This additional excavation is discussed in more detail under Liquefaction below. Liquefaction The primary geologic impact related to the project is the potential for seismicity and liquefaction. The proposed project would expose new structures,including private residences and public r roads, to the potential impacts of liquefaction. The Kleinfelder report confirms that the entire site is in an area susceptible to liquefaction. To minimize the risk of liquefaction, the project design includes the following construction measures for the proposed levee system: • Excavate, rework and densify the loose clean and silty sands under the levee to a depth of 10 to 15 feet. Deep Dynamic Compaction (DDC) techniques could also be used. These techniques could involve dropping a heavy weight repeatedly at a given location. • If Deep Dynamic Compaction is used, vibration from this construction technique would be monitored along the property line closest to adjacent residences. However, vibration from DDC would not be expected to exceed safe limits beyond 150 feet from the excavation site and therefore would not affect any adjacent residences. Other methods of compaction may be employed such as vibrating sheeps foot or pneumatic roller depending soil type and location. The methods described above are standard construction techniques and would reduce liquefaction potentials to a less-than-significant level. It should be noted that even if the project is bounded by engineered levees that are Zdesigned to withstand grounds shaking without liquefaction, liquefaction of sands inside the project could occur unless proper mitigation measures are implemented. Other Potential Soil Impacts Other potential soil related impacts of the proposed project include: ground subsidence; differential settlement; and erosion. 3-157 Subsidence is the gradual settling or sinking of an area with little or no horizontal motion. i Causes of subsidence include oxidation, solution, thawing, drying, wetting, subsurface compaction,tectonic downwarping or a combination of these factors. Man-made subsidence can be caused by removal of solids, liquids and gas from beneath the ground surface. Subsidence caused by these processes may be rapid and may have significant impacts on the structures located in the area of subsidence. Subsidence in the Delta and project area has been occurring since these areas were reclaimed and put into agricultural production in the late 19th and early 20th centuries. Reclamation and agricultural activities have resulted in land subsidence ranging from 1 to 3 inches/year (USGS, 1991). The proposed project may cause localized subsidence during construction as a result of groundwater pumping for lake, channel and levee construction. This could result in localized impacts if not properly monitored and mitigated. The potential for subsidence from dewatering would be short-term(only during dewatering activities). Dewatering activities are expected to occur during the excavation for the lake and channels,construction of the levee and installation of underground utilities. Dewatering activities would affect the top 15 to 20 feet, which would not affect most domestic wells around the project site which are generally below the depth of the dewatering activities (Bohley, 1992). According to the applicant, the localized dewatering activities are not expected to cause subsidence on adjacent properties because draw down would only occur on the project site immediately under or adjacent to the dewatering area. To confirm that dewatering activities would not impact groundwater levels in surrounding areas,the project would include a groundwater monitoring plan to provide early detection of changes in the groundwater level and to allow adjustments in the construction techniques if necessary. Monitoring wells and settlement plates would be placed on the project site and surrounding properties to control the groundwater level. Levee construction, along with subsequent consolidation would reduce the permeability of the soils directly under the levee (to a depth of approximately 10-20 feet). Most producing ' wells are at a depth of approximately 200 feet (Bohley, 1992), hence, groundwater resources would not be impacted. Settlement/consolidation(used interchangeably in this report)is generally caused by filling or placement of structures on the soil. Differential settlement (uneven settlement) can result in damage to structures and infrastructure in the area of settlement. The proposed project may cause localized soil settlement as a result of construction of the proposed levees and homes. Construction of the proposed levee system would add significant weight on top of near surface soils potentially causing settlement. Construction of project homes would also add weight to near surface soils but would not be considered as significant as the proposed levees. According to the Phase I geotechnical analysis, settlement associated with the proposed project would not be considered a significant impact. (Kleinfelder, 1988). Construction of the proposed project would result in grading over much of the site for. construction of the proposed homes,golf course,lakes and other facilities. These activities would expose soils to wind and water erosion. Because the project site is located in an area which experiences strong winds, wind erosion could result in a significant loss of soil without 3-158 mitigation. The most significant grading and excavation would be required for construction of the proposed lake and channels. The lake and channels would cover approximately 60 acres and would be excavated to a depth of approximately 16 feet. Excavation would primarily take place in fine grained, poorly graded, silty sands and sands having generally 5 to 15 percent fines. The- near surface sands are loose to medium dense to a depth of 15 feet. Excavation for the lakes would also result in intrusion into groundwater which varies in depth on the site. Impacts related to groundwater intrusion are discussed in Chapter 3.7 Hydrology and Drainage. The material excavated to create the lakes is proposed to be used for construction of the proposed levee system around the project. The geotechnical investigations indicate that the on- site soils are suitable for levee construction. Conformance with Soil Resource and Seismic Hazard Policies/Implementation Measures Available geotechnical reports indicate geologic hazards can be mitigated. Hence, the proposed project conforms to General Plan seismic policies 10-2, 10-9, 10-18, 10-21, and 10-33 regarding geotechnical analyses and the need to demonstrate that serious risks to life can be appropriately mitigated. Specific comments are as follows: i • A Phase I Geotechnical Investigation Report has been prepared. • A second phase of soil borings has been conducted to provide information for construction of the proposed levees to FEMA standards. This information is contained in the "Report Evaluation of Proposed Levees Bordering - Cypress Lakes Project". • Additional analysis would be conducted during the final design of the project to provide specific geotechnical recommendations for various aspects of project construction. • The project would include measures to address potential liquefaction by excavating, reworking and densifying the soils under the perimeter levee or through the use of deep dynamic compaction techniques. These measures would also apply to the construction of houses, roadways and other structures on the project site. Policies 10-3 and 10-2- pertain to the design of structures to withstand seismic activity. Because specific designs will be provided at a later stage in the project planning and approval process, an evaluation of project conformance is not possible at this time. However, the need to design structures to perform satisfactorily under earthquake conditions is essential to safety. A condition of approval should require that each structure be evaluated and recommendations made to ensure satisfactory performance. The project would be consistent with General Plan soil resource policies 8-63 and 8-68 regarding the need for erosion control measures as follows: 3-159 r • The applicant will be required to submit an erosion control plan prior to the County for approval at the time of application for a grading permit. This is routine requirement of the Building Inspection Department. MITIGATION MEASURES The project applicant has proposed the following mitigation measures to reduce potential . geotechnical impacts associated with development on the project site. 3,8-1 Excavate, rework and densify the loose clean and silty sands under the levee to a depth of 10 to 15 feet. Deep Dynamic Compaction (DDC) techniques could also be used. These techniques could involve dropping a heavy weight repeatedly at a given location. 3.8-2 If Deep Dynamic Compaction is used, vibration from this construction technique �. would be monitored along the property line closest to adjacent residences. However, vibration from DDC would not be expected to exceed safe limits beyond 150 feet from the excavation site and therefore would not affect any adjacent residences. 3.8-3 Groundwater monitoring plans to provide early detection of changes in the groundwater level and to allow adjustments in the construction techniques if necessary. Monitoring wells and settlement plates would be placed on the project site and surrounding properties to control the groundwater level. 3.8-4 The erosion control measures proposed for the project shall be a part of all construction activities. These measures include the following: • Existing vegetated areas should be left undisturbed until construction of site improvements is actually ready to commence. • All disturbed areas should be protected from both wind and water erosion upon the completion of grading activities. • Runoff should be directed away from all areas disturbed by construction, if practical. • Temporary check dams, sediment ponds, or siltation basins should be used to trap eroded soils, and prevent their discharge into storm drain pipes. , • To the extent possible, major site development work involving earth moving and excavations should be scheduled for the dry season. 3-160 • Areas used for stockpiling and staging construction equipment and materials should be located so that unchecked runoff from these areas does not enter the storm drain system. (Responsibility: Project Applicant) While the erosion control measures listed above will reduce dust emissions and nuisance at neighboring residences, the potential for dust to cause a nuisance at neighboring residences t would still exist due to the windy conditions of the site. This would result in a short term, periodic unavoidable impact on local residents. The following mitigation measure is proposed to ensure that potential impacts on liquefaction and settlement are addressed during final design of the project to mitigate potential impacts to a less-than-significant level. 3.8-5 The Kleinfelder report analyzed alternative approaches for mitigating liquefaction impacts. The project should be required to adhere to these approaches. The specific approach will depend on site-specific conditions and analysis. However, the project applicant should follow the reviewed and approved recommendation of the Kleinfelder report. A report documenting the methods used in the field to reduce liquefaction potential should be submitted to the Public Works Department and the public agency responsible for maintenance of the levee system. (Responsibility: Project Applicant) The project includes measures to monitor ground subsidence resulting from dewatering activities for project construction. The following mitigation measure is proposed to ensure these measures are implemented in the field. 3.8-6 The ground settlement monitoring plan should be finalized and submitted to the County for review and approval prior to beginning any construction or dewatering activities. The plan shall identify the location of all monitoring wells, and provide specifics on well completion and the method and frequency of monitoring. Similarly, the plan shall identify settlement plates as well as contingency plans to control subsidence or mitigate subsidence related damage. (Responsibility: Project Applicant) The following mitigation measures are proposed to ensure that erosion from construction activities is minimized to acceptable levels: 3.8-7 Post at the construction site the name and phone number of a designated dust control coordinator who can respond to complaints by suspending dust-producing activities or providing additional personnel or equipment for dust control. In addition contractors shall implement, at a minimum, the following measures: 1) Schedule earthmoving activities, as much as possible, during the early spring months when soil moisture is high. 3-161 2) Suspend earthmoving or other dust-producing activities during periods of extreme winds. 3) Provide equipment and staffing for watering of all exposed or disturbed soil surfaces at least twice daily, including weekends and holidays. An appropriate dust palliative or suppressant, added to water before application, should be utilized. 4) Water or cover stockpiles of debris, soil, sand or other materials that can be blown by the wind. 5) Sweep adjacent streets of all mud and debris, since this material can be pulverized and later resuspended by vehicle traffic. _ 6) Where possible, limit the speed of all construction vehicles to 15 miles per hour while on site. 7) Seed, cover or chemically treat finished grades as soon as practical after completion of activities. (Responsibility: Project Applicant) The following mitigation measure is proposed to ensure that all structures constructed on the project site will perform satisfactorily in the event of an earthquake and liquefaction on the project site. 3.8-8 Building plans for each structure to be constructed on the.project site shall include an evaluation and recommendations to ensure satisfactory performance in the event of an earthquake and liquefaction on the project site. The building plans shall be reviewed and approved by Contra Costa County prior to the'issuance of building permits. (Responsibility: Project Applicant) �. Implementation of the mitigation measures identified above would reduce potential geotechnical impacts associated with development on the project site to a less-than-significant level. r. 3-162 3.9 PUBLIC SERVICES This section of the EIR addresses the provision of various public services for the proposed project including: fire protection, police protection, schools, parks and other recreation facilities, and other government services (specifically mosquito abatement). This section also addresses applicable policies from the Contra Costa County General Plan, including key growth management issues. Policies are presented under "Existing Setting'; project consistency with s these policies is described under Impacts. Where impacts have been quantified on the basis of the number of residential units proposed by the project, the figure of 1,330 units has been used as a worst case. The net number of additional units would be 1,322 after deducting the eight existing residences that would be demolished as a result of this project. rFIRE PROTECTION EXISTING SETTING Existing Services The northern portion (or approximately one-third) of the project site lies within the Bethel Island Fire Protection District (Bethel Island FPD). The southern portion of the site (approximately two-thirds)is within the Oakley Fire Protection District(Oakley FPD) (see Figure 3.9-1). Bethel Island Fire Protection District The Bethel Island FPD's jurisdiction covers Bethel Island and the northern portion . (approximately 40%) of Hotchkiss Tract,from Dutch Slough/Jersey Island roads to Sandmound Slough, with a southerly panhandle covering the development along Sandmound Boulevard. The District operates from a single station located on Ranch Lane in the commercial core of Bethel Island. The District is staffed by a full time chief, an assistant chief, a fire captain, a full time secretary, and a force of 25 to 30 volunteers. It operates on an annual budget of approximately �Y P g PP Y $450,000 and has an Insurance Services Office (ISO) rating of 5. ISO ratings are insurance classifications ranging from 1 (best) to 10 (worst). Equipment consists of three engines, two water tenders, two powerwagons, a rescue vehicle, two fireboats and a pickup for general utility use. The District uses Regional Ambulance Service on Lone Tree Way in Brentwood for paramedic services. Completion of the Bethel Island FPD's Five Year Plan is contingent upon resolution of the fire district boundaries. A previous application for incorporation of the City of Oakley included Hotchkiss Tract. However, this application has been revised and no longer includes Hotchkiss Tract. The consolidation of the East County fie protection districts (Bethel Island, Oakley and Riverview)is also under consideration. Plan checking services are currently provided by the Riverview Fire District under contract to the Bethel Island FPD. (Bethel Island FPD Chief Jack Whitener, personal communication May 5, 1992). 3-163 Vii•., • .•. � �`o �G ��: ,y J �` _ �• T. o Frank Jersey Island B/eetthelIsland. _ Imo+ ;.;••��;.: �.✓ r - � ��� r Bethel Island. ' .c -F•,n �, Holland Tract i Statin _• - - ��--� c. '. Contra Costa- = -Dalley' Sheriffs Station < � �o- ' _ OakleyFire� Project Site c S - - ProtectionStanon 0ak1Cy Fire, _ Protection Station • _A ...•� ' r1.` y Brentwood N v,;a '~ .`�. - a i. a � i as z..__-._— :vn• _ :al = __:ms`s.- Figure 3.9-1: CYPRESS LAKES & Fire District Boundaries and Location COUNTRY CLUB PROJECT of Sheriff Station 3-164 The District's most important need is for the creation of a municipal water supply throughout the Planning Area. The lack of a municipal water supply requires that water be obtained from sloughs or must be brought by truck to fire sites. The use of slough water, which has a high mineral content, tends to damage the pumping equipment. There are six fire hydrants in the District, all located on Bethel Island. Additional problems include a shortage of land for use as a training site. The District has indicated that at least one additional fire-fighter is needed at this time. (Whitener, May 5, 1992). Oakley Fire Protection District 1 The Oakley FPD encompasses a 32-square-mile area, including the southern portion (approximately 60%) of Hotchkiss Tract. The District has a first-response station in Knightsen ` (#94) with a back-up station in Oakley (#93). The District is staffed by 52 volunteers, including one full time firefighter, a part time chief, a part time assistant chief, a recording secretary, and three on-call maintenance workers. The District has an annual operating budget of approximately $406,000, and an ISO rating of 3. Equipment at each station consists of three Class A pumper trucks, powerwagon, and van for rescue and medical calls. With creation of a new station, the District would require an additional pumper truck. The District's Five Year Plan mentions the need for enlargement of the Oakley Station. Plan checking services are currently provided by the Riverview Fire District under contract to the Oakley FPD. (Oakley FPD Assistant Chief Manual Tovar, personal communication May 5, 1992 and OFPD Chairman Gene Stonebarger, correspondence, September 25, 1992). Fire District Funding The Bethel Island and Oakley FPDs have the same primary sources of funding: property taxes and a Special Districts Augmentation Fund (SDAF). Thirty percent of the local property tax revenue goes directly to the appropriate fire district. The rest is paid into the countywide ,. SDAF to be redistributed among all fire protection agencies throughout the County on an �- as-needed basis as determined by the Board of Supervisors. The County has designated the entire Bethel Island FPD as an overextended service area and established a Fire Facilities Fee of$488 for each new single-family dwelling unit and $0.30 per square foot of other new construction, except for multiple-family residential and mobile homes. The fees are subject to annual review (Fire Protection Facilities Fee for the Bethel Island Fire Protection District,adopted by the Contra Costa County Board of Supervisors, Oct. 31, 1989). The County levies a .$480 fee on all new buildings within the Oakley FPD. The Oakley FPD has indicated that they receive approximately 82% of their funding from local property tax revenues and 18% from the SDAF. The Oakley FPD has also indicated that they currently have approximately $1,000,000 in their construction budget. (OFPD Chairman Gene Stonebarger, correspondence, September 26, 1992). 3-165 General Plan Policies and Growth Management Standards General Plan fire protection goals, policies and implementation measures were adopted in order to provide efficient fire service through the land use planning and review process. Those which are most directly applicable to the project are listed below. Project consistency with these policies is discussed under "Impacts". • The County shall strive to reach a maximum running time of three minutes and/or 1.5 miles from the first-due station, and a minimum of three firefighters to be maintained in all central business district, urban and suburban areas. (Policy 7-63) - • The County shall strive to achieve a total response time (dispatch plus running and set-up time) of five minutes for 90 percent of all emergency responses. (Policy 7-64) The Growth Management Element permits the use of automatic fire sprinkler systems to satisfy this standard. • New development shall pay its fair share of costs for new fire protection facilities and service. (Policy 7-65) • Needed upgrades to fire facilities and equipment shall be identified as part of project environmental review and area planning activities. (Policy 7-66) • Sprinkler systems may be required in new residential structures, where necessary to protect health, safety and welfare. (Policy 7-67) • Fire fighting equipment access shall be provided to open space areas in accordance with the Fire. Protection Code and to all future development in accordance with Fire Access Standards. (Policy 7-74) • All new traffic signals shall be equipped with preemptive devices for emergency response _ services. Existing traffic signals significantly impacted by new development shall be retrofitted with preemptive.devices. (Policy 7-75) • The five-year plans of the fire agencies should be updated to be consistent with the County General Plan. The fee ordinances should also be amended and fees increased as required to meet new capital requirement. (Policy 7-87) • Fire protection agencies shall be afforded the opportunity to review projects and submit conditions of approval for consideration to determine whether there is an adequate water PP q supply for fire fighting; road widths, road grades and turnaround radii are adequate for emergency equipment; and structures are built to the standards of the Uniform Building Code, the Uniform Fire Code, other State regulations, and local ordinances regarding the use of fire-retardant materials and detection, warning and extinguishment devices. (Implementation Measure 7-av) 3-166 rThe County Building Inspection Department and Community Development Department shall submit building and development plans for all new construction, including remodeling, to the local fire protection agency to assure that fire safety and control features are included that meet the adopted codes and ordinances of that agency. (Implementation Measure 7-aw) Pursuant to the Growth Management Program, appropriate fire districts shall review all development plans to assess the adequacy of fire protection services. If the response time is more than five minutes, special building design features may be imposed. Fire stations shall be located within 1:5 miles of development. If this condition cannot be satisfied, then development will not be allowed to proceed. However, the Growth Management Element permits automatic fire sprinkler systems to be used to satisfy this requirement. Any new facilities or design improvements necessary to meet fire protection standards shall be paid for by new development. Responsibility for fire safety review of development projects is that of the applicable agency,or agencies. In addition, the Community Development Department relies upon standards contained in the Contra Costa County Code(Title 9: Subdivisions). The current County Sprinkler Ordinance requires that developers provide all home buyers with the option of sprinkler installation. The General Plan endorses an amendment to the Code that would require all new residential construction to install sprinklers in all units. In 1986, the County adopted an ordinance to allow the establishment of fire facility fees. This policy is currently being implemented via ordinances establishing the exact amount of the fees for specific agencies' service areas. IMPACTS Proiect-Specific Fire Protection Facilities The proposed project would increase fire protection service demands on the fire districts by increasing the number of structures and population within the project area. To reduce the project's impacts on fire services, the project would include construction of a fire station near the project entrance at Cypress Road and Bethel Island Road. This station would satisfy the County's standard that fire stations be located within 1.5 miles of development, and the Bethel Island and Oakley fire district standard for maintaining the five minute/1.5 mile response standard. The proposed project, therefore, is not expected to have any adverse impacts on fire protection facilities. The Riverview Fire District would conduct the plan checking for the project under contract to the Bethel Island and Oakley FPDs, with the participation.of both Districts. The Bethel Island FPD expects that the proposed fine station at Cypress Road, with additional 3-167 equipment and personnel, would satisfy the future needs of the District. The District will be particularly concerned that the development plans provide adequate access to the,proposed lakes for rescue vehicles. (Bethel Island FPD Chief Jack Whitener, personal communication, May 5, 1992.) The Oakley FPD has expressed a desire to continue service to the site and has indicated that the district currently has adequate resources to staff the proposed station. (OFPD Chairman Gene Stonebarger, correspondence, September 26, 1992) Water The applicant also proposes annexation to the Oakley Water District (OWD). The OWD has provided a "will serve letter" indicating that water demands for the project,can be adequately provided by the OWD (see Appendix F). The availability of a dependable water supply would have a positive impact on fire protection services both on the project site as well as surrounding areas. In addition to domestic water supplies, the project site would have an alternative source of water for fire fighting as a result of the proposed lakes and channels. Fees According to the fee schedules now in effect, development fees of approximately $635,000 for the residential component of the proposed project would be required. Additional fees would be assessed on other new construction associated with the project such as the golf � course club house and day care facilities. However, these fees are subject to annual review and can be expected to increase. The project may receive credit for fire fees (portion or all) for dedication and construction of the proposed fire station on the project site. , Annexation Issues With the existing fire protection service boundary rylocations the Bethel Island FPD would serve the northern one-third of the project site. Access to this portion of the Bethel Island FPD service area would be via Sandmound Road at the site's northern boundary or through the Oakley FPD service area, via Cypress Road. The Oakley FPD would serve the southern two-thirds of the project site. The Bethel Island FPD would collect a Fire Facilities Fee of$488 per residential unit, plus $0.30 per square foot of other construction. The Oakley FPD would collect a development fee of$480 on all new buildings. However, having the project site served by two separate fire districts would not appear to be practical. The Bethel Island FPD Chief believes that Hotchkiss Tract should be included within a single fire district, preferably the Bethel Island FPD, subject to the desires of affected property . owners. It is preferable to have development fees credited to a single fire district. It is also preferable to have funds administered by a single district; from an administrative standpoint, it is impractical to create a situation in which, at times, the district responding (servicing fire district) must be reimbursed by another district (home fire district). (Whitener; May 5, 1992) 3-168 The project applicant is proposing to petition LAFCO for annexation of the remaining portions of the site to the Bethel Island FPD. The Oakley FPD has expressed the desire to continue to serve the project site. (OFPD, Chairman Gene Stonebarger, correspondence, �. September 26, 1992). Relationship to the General Plan The proposed project is generally consistent with the goals, policies and implementation measures of the Contra Costa County General Plan regarding fire protection in the following ways: • The project proposes to construct a new fire station on the project site and may pay approximately $635,000 in fire protection fees. The applicant may receive credit for fire fees for the dedication and construction of the station. Construction of a fire station on- site would also meet the County's policy regarding response times. (Consistent with policies 7-63 thru 7-66) New property taxes and special district fees along with the existing taxes will pay for the cost to provide services for new facilities. Other County policies related to fire protection would.be complied with through the normal building inspection and plan review process. Bethel Island Area The General Plan concludes that the allowable build-out of the Bethel Island would necessitate the expansion of the existing on-island facility on Ranch Lane to a full-service facility and the establishment of one or more substations to meet the County goal of a three minute response or 1.5 miles maximum distance between development and station. The recommended improvements to the existing station include making it the base location of emergency response apparatus, administration, training and maintenance. The staff would be expanded to three 24-hour paid positions with appropriately expanded living quarters. At least one substation would be required to provide a five minute response time. That station would have a single piece of apparatus and less than full staffing. This sub-station may be provided by the Cypress Lakes Project. At full build-out of the Planning Area, and assuming a uniform distribution of new residential units throughout Hotchkiss Tract, the Bethel Island FPD would serve an estimated � 3,336 residential units [2,136 on-island andpossibly, 1,200 off-island (3,000 du x 40% along with commercial and recreational development. At full build-out of the Planning Area, the Oakley FPD would serve an estimated 1,800 new residential units (3,000 du x 60%), along with commercial and recreational development, within the Planning Area. Construction of a fire station in the vicinity of Cypress Road and Bethel Island Road,as proposed by the Cypress Lakes project, would allow either District to meet the three minute/1.5 mile response standard.. 3-169 MITIGATION MEASURES With construction of the proposed fire station in the vicinity of the project entrance at Cypress Lane and Bethel Island Road, payment of fire protection fees (if required), and annexation of the project site to the Oakley Water District, the fire protection impacts of the proposed project would be reduced to a level of insignificance. The following mitigation measures are proposed to ensure adequate fire protection facilities are provided in the'project area prior to project completion: 3.9-1 The project proposes to dedicate a site and construct a new fire station on the project site in lieu of fire protection fees as determined by the County. The site and station should meet all applicable requirements of the appropriate Fire District ' (Oakley FPD or Bethel Island FPD). The fire station should be operational prior to the first homes on the site being occupied. If necessary a special district fee may be augmented to provide adequate funding to fully staff the new station. (Responsibility: Project Applicant/Fire District) I�3.9-2 If the project is required to pay fees, the Fire District fees shall be based on the fees in effect at the time of the issuing of building permits. (Responsibility: Project Applicant) The following mitigation measure is proposed to insure proper review and approval by the fire districts prior to issuance of the building permits. This measure is based primarily on measures in the County General Plan: 3.9-3 All building plans shall meet the applicable Uniform Building and Fire codes. Fire protection agencies shall be afforded the opportunity to review and comment on plans prior to the issuance of building permits for the projects. (Responsibility: Contra Costa County/Fire Districts) The mitigation measures identified above would reduce the project's potential impacts on fire protection service to a less-than-significant level. POLICE PROTECTION Y I � EXIST NG SETTING Existing Services Police protection services throughout the Planning Area are provided by the Contra Costa County Sheriffs Department, which is headquartered in Martinez and has a station house (Delta Station) located at the junction of Acme Street and O'Hara Avenue in Oakley (see Figure 3.9-1). The Planning Area is covered by one beat, Beat 31, operating out of the Delta Station. The 3-170 Station is staffed by one lieutenant, five sergeants and 23 deputies and has a total of 13 patrol cars. Five deputies, working in shifts, and a patrol car are assigned to Beat 31, with one deputy patrolling at any one time. In addition, the County Sheriff's Department operates a marine patrol which consists of two deputies. In the future, Delta Station will be under the supervision of a sergeant, rather than a lieutenant. Other staffing changes may be made, contingent upon the outcome of the current County and State budget process (Sgt. Phil White, personal communication May 7, 1992; Reed McDonald,personal communication August 7, 1992). Police work within the area covers a wide spectrum of problems, including responding to disturbance calls, fights, threats, burglaries and robberies. At present, the Department feels that the degree of service needs to be strengthened, and that any further development in the area may tax the service beyond its available capacity. Y P For the Bethel Island Area, the County General Plan, sets forth a minimum police protection standard of"155 square feet of station area per 1,000 residents." No formal minimum p q level of service standard has been established for the East County Area. Most police protection agencies do not estimate staffing needs on a per capita basis, although a rough ratio of 1 officer for each 890 new residents would be desirable. In estimating potential demand for services, it is the Department's practice to review each new project on a case-by-case basis for its public safety aspects, location, and other factors. (Parsons, May 12, 1992.) Police protection services are funded almost exclusively through the Special Districts Augmentation Fund from the County General Fund. (County Auditor, May 12, 1992) In an attempt to extend the level of police service in the Bethel Island, Oakley and Discovery Bay areas, there have been proposals to create special tax districts that by popular vote would levy i� taxes to cover the cost of such an extension. If a special district is approved, adequate funding would be provided so that police protection services would improve to accommodate a reasonable amount of new development. General Plan Policies and Growth Management Standards The Public Services/Facilities Element of the County General Plan contains adopted goals, policies and implementation measures to provide an acceptable level of police protection service for the projected population and to improve the level of efficient police protection needed through the land use planning and review process. Those which are most directly applicable to the ,. proposed project are listed below. Project consistency with these policies is discussed under "Impacts" (page 3-176). • A sheriff facility standard of 155 square feet of station area per 1,000 population shall be maintained within the unincorporated area of the County. (Policy 7-58) ~ Sheriff patrol beats shall be configured to assure minimum response times and efficient use of resources. (Policy 7-59) 3-171 r • A maximum response time goal for priority 1 or 2 calls of five minutes for 90 percent of all emergency responses in central business district, urban and suburban areas, shall be strived for by the sheriff when making staffing and beat configuration decisions. (Policy 7-60) • Levels of service above the county-wide standard requested by unincorporated communities shall be provided through the creation of a County Service Area or other special governmental unit. (Policy 7-61) • Maintain a sheriffs sub-station in each geographical area of the County (East, West, Central, South Central) to serve the individual needs of that area, if warranted. Facility size should be guided by Policy 7-58 and should be commensurate with staffing needs, with provision for future expansion to match projected increases. (Implementation Measure 7-am) • In developing areas the Sheriff protection service standard shall be achieved by creation of a County Service Area and special tax and/or creation of a Mello-Roos Community Facilities District that generates special tax revenue to support additional increments of Sheriff patrol necessary to meet the adopted service standard. Developers, prior to receiving development approvals, should agree (via a Development Agreement or a landowner election) to participate in such special funding districts. (Implementation Measure 7-aq) The Contra Costa County Sheriff's Department provides police protection services for all unincorporated areas. According to the Growth Management Element, the Sheriff's facility standard provided above is based on the County's existing facilities of approximately 155 square feet of floor area per 1,000 population in six locations throughout the County. IMPACTS Proiect-Specific Police Protection Facilities The proposed Cypress Lakes project would result in the addition of approximately 3,247 persons to the County Sheriff's service area. This would result in the need for new officer positions and equipment. Funding The costs of the increased services would be paid from the Special Districts Augmentation Fund, which is part of the County's General Fund allocated for police protection service in the unincorporated areas and distributed on an as-needed basis. 3-172 With an estimated population of 3,247 new residents at build-out, the proposed Cypress Lakes project would need to provide approximately 465 square feet of additional space to maintain the County's adopted standard of 155 square feet per 1,000 population. The Cypress Lakes project proposes to satisfy the standard of 155 square feet of station area per 1,000 residents by contributing monies to expand the station house (Delta Station) located in Oakley. (Applicant's Growth Management/Measure C Compliance Statement) Relationship to the General Plan The proposed project would be generally consistent with the police protection policies of the Contra Costa County General Plan by contributing monies for the expansion of the Delta Station in Oakley. As a course of County review of new subdivisions, the County Development Department submits the plans to the Sheriff's Department for review and comments. With regard ' to the Cypress Lakes project, no comments were received from the Sheriff's Department. Bethel Island Area The growth expected under the County General Plan in the Bethel Island area would require additional Sheriff's Department personnel,facilities and equipment. No formal minimum level of service on a per capita basis has been adopted for the East County Area, and factors such as the public safety aspects and locations of individual development projects are used by the Department to forecast staffing and equipment needs. (Lt. Scott Parsons, Sheriff's Department, personal communication May 12, 1992.) Full build-out of the Bethel Island Area would require additional officer positions and growth in other unincorporated East County areas would add to the cumulative demand. New Sheriff beats and, perhaps, reorganization of existing beats, would be required as service demands increase in both the Bethel Island Area and adjacent developing communities. The increased number of required officers would generate increased need for support staff and space. The space needs may be met through an expansion of the existing Oakley facility, however cumulative growth and service demand in the vicinity may necessitate a new facility. The projected population increase of the Bethel Island Area would necessitate approximately 1,000 square feet of additional space to maintain the sheriff facility standard of 155 square feet of station per 1,000 population. MITIGATION MEASURES The following mitigation measure is proposed to ensure that the proposed project provides its fair-share towards the cost of rehabilitating the Delta Station in Oakley: 3.9-4 The proposed project should pay a fair-share fee equal to the cost of providing 465 square feet of new Sheriff Department facilities, based on the County standard 3-173 of 155 square feet per 1,000 residents. The fee should be calculated and paid at the time of issuance of building permits for the project. (Responsibility: Project Applicant) Implementation of this mitigation measure would reduce the project's impact on public protection services to a less-than-significant level. SCHOOLS EXISTING SETTING Existing Services The project site falls within the jurisdiction of two school districts: Oakley Union School District for kindergarten through eighth grades, and Liberty Union High School District. (See Figure 3.9-2.) Children throughout the Planning Area are bused to school. The East Contra Costa School Transportation Department, a consortium of the Brentwood and Oakley Elementary School Districts and Liberty Union High School District, provides busing for the bulk of the Planning Area. Oakley Union Elementary School District has four elementary (K-5) schools: Oakley Elementary School located at 501 Norcross Lane, Gehringer Elementary School located at Highway 4 and Bolton Road, Laurel Elementary School located at 1141 Laurel Road, and Vintage Parkway Elementary School located at 1000 Vintage Parkway. The District operates one "middle school", O'Hara Park School (grades 6-8) located at 1100 O'Hara Avenue, at the corner of O'Hara Avenue and Cypress Road. Classroom sizes range from 25 to 32 children for every teacher. All schools are presently at capacity, and portable rented classrooms are used to accommodate the student population. (Bennett, May 20, 1992) Liberty Union High School District has one school: Liberty Union High School (grades 9 through 12, with a capacity for 1,250 students) located in Brentwood. A typical class size has over 30 students. The school is currently over capacity with a current enrollment is 1,809 students. The District recently completed a master plan which provides for a student capacity of 2,078. The plan is expected to be fully implemented by the end of the 1992 enrollment year. The State Department of Education projects enrollment to increase to 2,672 students in enrollment year 1995-96,however with increased housing demand the projected enrollment could occur a year earlier. In addition to expanding the existing campus, the school district purchased a second high school site in Oakley. The new facility is planned to have a capacity for 2,200 students, with completion of construction anticipated in August 1995. Proceeds for the purchase of the site were generated from a 1988 Obligation Bond passed by voters. Funding alternatives. for the construction of the Oakley facility are being reviewed by the District. However, without funding participation by both county and city development, the facility cannot be built. (Liberty Union High School District, February 18, 1992) 3-174 fel t . . . . . ^��.. T. .'':J•'' ' . . . . . . . . . . . ;} t�:`~{ •"� < • / - � —. . , -•: . � . E :�: . .•�,•� � • : . . . :;: . �` mar/ ,• '' .•� f`r •+ : �t� Y. : /.! _1� ... .� / . . . . . . . . . . . . . ♦• awcl 77 J&ic:Y:W�fia -�.- . • . .•tea• . • • . . . • • ��.�t�• p,,:y . . • • .46 • w >':= _ ::::�;. . . i - . ;s. . . ;Holland 17ract; o` . r .i••:- mss. . Cr.. •. reg" . . . __ ...:..•�• s :.,=.•.;::,,.:;. : ... 'l.. .:�.?'. -7- Oak-ley_ .. :.�. . . :x — _ Oakley .�...,.. .._•... 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Los ifs _(��_— � '•� I 'tee- ��• _ • Figure 3.9-2: CYPRESS LAKES & COUNTRY CLUB Location of School Facilities in the Project Area PROJECT �' 3-175 Funding Both Oakley Union Elementary and Liberty Union High School districts are funded primarily by the State Department of Education, with a small amount of Federal funding (less than two percent) and remainder made up from local taxes collected within the District itself. At present, developer fees are collected on all new projects built within District boundaries; the fees are $1.65 per square foot for every new house and $.26 for every new square foot of industrial or commercial space. Out of this revenue, Oakley Union Elementary School District collects 70 percent and Liberty Union High School District collects 30 percent because enrollment has been increasing much more rapidly in the elementary schools than in the high school. Were development to increase much more rapidly within the districts, the most likely source of additional funding would be through further increases in developer mitigation fees, State building aid, and school bonds. Alternatively, a Mello-Roos tax district could be created r in which each property would be taxed on a permanent, annual basis; this would significantly increase the amount of funding available for school provision within the District. On April 14, 1992, Measure 'D" which would have provided $25 million bond for school facilities was defeated by the voters on Oakley/Bethel Island. (Bennett, May 20, 1992.) ` General Plan Policies and Growth Management Standards The County General Plan Public Services/Facilities Element contains adopted goals, policies and implementation measures to accommodate the projected population growth and achieve State-adopted standards in the provision of school facilities in all areas of the County. The following excerpts are those most directly applicable to the proposed project. Project consistency with these policies is discussed under "Impacts" (see page 3-182). • To provide new schools in optimal locations to serve planned growth. (Goal 7-AP) • To assure that school facilities are adequate r q o committed to be adequate, prior to approvals of major applications for residential growth. (Goal 7-AR) The environmental review process shall be utilized to monitor the ability of area schools • p Y to serve development. (Policy 7-141) • During the development review process, the State classroom size standards set by each district for primary and secondary schools shall be used as the basis for detemiining the adequacy of area schools. (Policy 7-142) • The hearing body in reviewing residential projects shall consider the availability of educational facility capacity. (Policy 7-144) ' 3-176 • The development of quality schools shall be supported by coordinating development review with local school districts including such activities as designating school sites, obtaining dedications of school sites, and supporting local fees, special taxes, and bond issues intended for school construction. (Policy 7-145) • Adequate provision of schools and other public facilities and services shall be assured by coordinating review of new development with the cities and other service providers through the Growth Management Program, the environmental review process, and other means. (Policy 7-146) • School site donation by developers shall be encouraged through the use ofdensity transfer or other appropriate land use alternatives. (Policy 7-147) • The development of school facilities shall be provided in conjunction with and adjacent to local parks and trail ways. (Policy 7-148) �l • The County shall support school facility fees for growth-impacted school districts. (Policy 7-151) Although the State of California has preempted the field of provision of school facilities through exactions on development projects, it is the responsibility of local government to ensure that the timing of growth is coordinated with the efforts of the school districts to provide school facilities. Currently, overcrowded attendance areas have been identified in many school districts in the County. In the East County area of Oakley, where much of the unincorporated growth will occur, schools are severely overcrowded. IMPACTS Cypress Lakes School Facilities The proposed project would result in the construction of 1,330 new residential units and associated recreational facilities based on the student generation factors provided by the school districts, the Cypress Lakes Project would be expected to have the following student enrollment: OUSD K-5 0.33 x 1,330 = 439 students 6-9 0.17 x 1,330 = 226 students LUHSD 9-12 0.19 x 1,330 = 253 students The proposed project would generate approximately 665 new elementary and middle school enrollments and approximately 253 new high school enrollments. 3-177 r At the present time, the Oakley Union Elementary and Liberty Union High School Districts have neither the capacity for additional students or the ability to fund new school construction. Therefore, students generated by the proposed project could not be accommodated by existing school facilities. Based on the project's student generation and the local school district's school facility requirements, the proposed project would require the construction of approximately one new elementary school, 30% of a new middle schools, and 20% of a new High Schools. To help mitigate the project's potential impact on local school district facilities the proposed project includes dedication of 7.4 acres for a school on the project site. This dedication would be in addition to the required development fees. The OUESD has indicated that a 10 acre school site would be desired. ± Development Fees/Funding The proposed project would generate approximately $4.4 million in development fees, based on the District's current fees (assumes 2,000 sq.ft./dwelling unit). Based on the existing split approximately $3.1 million would go to the Oakley Unified School District (70%) and$1.3 million would go to the Liberty Union High School District. As indicated previously, the fees generated by the project would provide a significant funding source for the school districts. �I In addition to development fees, the districts would also receive increased property tax revenue as a result of the change in land use of the project site and its higher assessed value. This increase in revenue would provide a long-term source of revenue for the school districts. While the project includes substantial mitigation measures in the form of land dedication and the payment of school impact fees, the local school districts have indicated that the project would still result in a significant adverse impact. Relationship to the General Plan The proposed project would be consistent with County policy regarding school facilities by including dedication of 7.4 acre for a school site within the project; paying the appropriate development fees (approximately $4.4 million) to the local school districts; and providing local parks and trails near the school site. M, Bethel Island Area The District requires a development fee of $1.58 per sq. ft. of residential construction. This is in the process of being negotiated to possibly $1.65 per sq. ft. (Kimberly Wood, Liberty Union High School District consultant,personal communication May 5, 1992.) Using the current fee schedule on new construction,a 2,000 sq. ft.residence would generate$3,160 for the District. The District requests that all new County development projects be conditioned to participate in 3-178 a funding plan to build the Oakley High School beyond developer fees. These fees and conditions would apply to all future residential development within the Bethel Island Area. (Liberty Union High School District letter to Community Development Department dated Feb. 18, 1992.) MITIGATION MEASURES The proposed project would be required to pay the applicable school impact fees as assessed by the local school districts. The following mitigation measure is proposed to ensure that the fees applicable to the project are those in effect at the time of project construction: 3.9-5 School impact fees shall be based on the fees in effect at the time of issuing building permits. (Responsibility: Project Applicant/OUSD/LUHSD) The following mitigation measures are proposed to mitigate the proposed project's impact on school facilities and the need for a new school site in the project area: 3.9-6 School impact fees are projected to be insufficient to cover the project's share of facilities required to serve new students in the area. If no state or local funding is available, the project applicant should work with districts to determine additional school fees to be paid as building permits are issued. (Responsibility: Project Applicant/OUSD/LUHSD) 3.9-7 The school site should be enlarged from 7.4 acres to 10 acres to meet the OEUSD requirements. (Responsibility: Project Applicant) 3.9-8 If the proposed on-site school site is determined by the OUESD to be unacceptable,the applicant shall pay an in-lieu fee to the OUESD for the purchase of an appropriate school site. (Responsibility: Project Applicant/School District) Implementation of these measures would reduce the project's impacts on school facilities to a less-than-significant level. t PARKS AND OTHER RECREATION FACILITIES EXISTING SETTING Existirig Services There are no County recreational resources on the project site or within the Bethel Island Area. Private facilities along the perimeter of Bethel Island and Hotchkiss Tract focus around a variety of water oriented recreational activities such as fishing, water skiing, wind surfing, sailing, speedboating and house boating. Inland, there is a 18-hole golf course located on 3-179 1 Gateway Road as well as opportunities for bike riding, bird watching, camping or shopping. -� Additionally,three planned development projects which include golf courses are proposed for the _ Brentwood area: A.G. Spanos Brentwood Hills Country Club, Hancock Specific Plan, and the Blackhawk/Nunn Project. General Plan Policies and Growth Management Standards The County General Plan contains adopted goals, policies and implementation measures to ensure that the recreational needs of present and future residents of the County are provided for. The following excerpts from the Open Space Element are those which are most directly : applicable to the proposed project. Project consistency with these policies is discussed under 'Impacts". • To develop a sufficient amount of conveniently located, properly designed park and recreational facilities to serve the needs of all residents. (Goal 9-H) • To develop a system of interconnected hiking, riding and bicycling trails and paths suitable for both active recreational use and for the purpose of transportation/circulation. (Goal 9-I) • To achieve a level of park facilities of four acres per 1,000 population. (Goal 9-K) • Major park lands shall be reserved to ensure that the present and future needs of the County's residents will be met and to preserve areas of natural beauty or historical interest for future generations. Apply the parks and recreation performance standards in the Growth Management Element. (Policy 9-32) • A well-balanced distribution of local parks, based on character and intensity of present and planned residential development and future recreation needs, shall be preserved. (Policy 9-33) • Park design shall be appropriate to the recreational needs and access capabilities of all residents in each locality. (Policy 9-34) • Public trail facilities shall be integrated into the design of flood control facilities and other public works wherever possible. (Policy 9-38) • Recreational development shall be allowed only in a manner which complements the natural features of the area, including the topography, waterways, vegetation and soil characteristics. (Policy 9-39) • Recreational activity shall be distributed and managed according to an area's carrying capacity with special emphasis on controlling adverse environmental impacts, such as 3-180 conflict between uses and trespass. At the same time, the regional importance of each area's recreation resources shall be recognized. (Policy 9-40) • Require that new development meet the park standards and criteria included in the growth management program. Ensure that credit for the park dedication ordinance requirements be given for private recreation facilities only after a finding has been adopted that the facilities will be open to and serve the public. (Implementation Measure 9=p) • Coordinate with the various school districts in the County to provide for the joint use of recreation facilities. (Implementation Measure 9-r) • Coordinate funds and programs administered by County government and other agencies, such as the East Bay Regional Park District, to obtain optimum recreation facilities development. (Implementation Measure 9-s) • Develop a comprehensive and interconnected series of hiking, biking and riding trails in conjunction with cities special districts public utilities and county service areas. (Implementation Measure 9-t) Local parks are areas of open space set aside for recreational use and are located within an acceptable distance from the people they serve. Parks are differentiated into neighborhood and community parks. Neighborhood parks generally have service areas equivalent to elementary schools, while community parks more commonly are equivalent to high school service areas. The size of a park will vary with the population to be served. The Open Space Element designates one community park on Bethel Island and three neighborhood parks for Hotchkiss Tract. County park standards for neighborhood parks are shown below: • Acreage/Population: 2.50 acres per 1,000 population. • Site Area: Without playground -- 3-7 acres; with playground -- 6-8 acres; with playfield -- 12-17 acres. • Location: Center of neighborhood. Facilities: (Park area.only ) Landscaped open space (trees, grass, shrubbery), benches and tables, and walks. • Service Radius: One-half mile. • Association: Neighborhood parks are best located adjacent to playgrounds, playfields and elementary schools. They may also contain a neighborhood ' recreation center. In areas planned for development, efforts should be made to encourage new County Service Areas to provide for maintenance of local parks. 3-181 The plan encourages the development of local feeder trails and paths to provide an interconnected system which can work as a circulation component as well as providing recreational opportunities. General Plan Bicycle Trails, Hiking Trails and Riding (Equestrian) Trails Maps show trails through the Hotchkiss Tract,either through or adjacent to the project site. Increasingly,private developments are being considered which provide on-site recreational facilities to serve project residents.- These facilities provide project amenities and are effective sales tools. They may limit the impact of new homes on the existing public park facilities; but, generally, they provide compatible facilities to those of the public parks. For this reason, credit from the park dedication ordinance requirements should only be given where it is clear that private developments provide facilities which are open to and serve the public. The Plan encourages the placement of such facilities in private developments and encourages the development of pathways that are integrated in location and design with those of adjacent projects. IMPACTS Project-Specific The proposed Cypress Lakes project is located in the off-island bonus residential area which provides higher density for residential projects that include substantial recreational amenities. The applicant's Feasibility Analysis of all Public and Semi-Public Recreational and Educational Areas, submitted Nov. 11, 1991, describes the proposed Cypress Lakes recreational amenities. These amenities are proposed to satisfy the Off-Island Bonus Area requirements for increased residential density and County park land standards. The project's proposed recreational amenities include: Golf and Country Club The applicant proposes a 170.3 acre semiprivate golf course where residents can be members allowing them preferred tee times and other privileges, while also allowing the public to play. Financing of the golf course business would be secured by the property and the revenues from golf sales and rentals. All costs to develop the course would be incorporated into the development cost of the single family lots. Maintenance and management would be contracted out to a professional, experienced company to handle day to day operations. In 1989, a preliminary study was done to survey the feasibility of the golf course and the proper type of course to build. The report stated that the Eastern Contra Costa County golf demand is dramatically under supplied. Golf courses incorporated with housing has become increasingly popular in the Contra Costa Area. There are as many as 14,600 potential golfers in Eastern Contra Costa County. The potential private club golfers is estimated at 2,300 in 1990, translating into potential demand for nearly 1,500 memberships. Subtract existing members at 3-182 v Discovery Bay, and this leaves 1,300 new golf memberships for 1990. This number is increasing each year especially with the rapid growth in the area. Furthermore, the public golf course demand in the Eastern County is drastically under supplied leaving 12,000 potential non-member golfers after allotting for future private memberships. There are a few new projects in the East ►�, County area proposing golf courses. Even with the approval of these projects a demand for golf courses would remain. iAs indicated above, there appears to be a sufficient market base to support a golf course at this site and the golf course would supply a recreational need which is lacking in the East County area. The proposed golf course is consistent with the Off-Island Bonus Area recreational goals which call for major recreational amenities such as a "golf course". Lake/Canal Areas The proposed project would include approximately 60 acres of lakes and canal-like extensions extending into other portions of the project site. The lake and channels are proposed as open space areas and to provide aesthetic features to the project. Boating would only be allowed on the lake and no skin-contact (swimming) would be allowed in the Lake or channels to maintain acceptable water quality. The Lake and channels would also provide bird and wildlife habitat and trails would be provided along these areas. The Lake and channels would be cared for, maintained and operated by the homeowner's association. Construction of the lake and waterways would be financed as part of the construction financing for the overall development of the project, possibly through a Mello-Roos Bond or alternative sources. Beach Club The Beach Club which is located on the lake would occupy approximately 1.5 acres of the project site and would be owned, managed, financed and maintained by the Homeowner's Association for the project. Memberships would be automatic upon home ownership. Homeowner's dues would be charged to each property owner. The 1,330 homes are more than ' enough to financially support such a center. Parks The proposed project includes 33.77 acres of park land. this would primarily consist of. one large community park located near the project entrance at Cypress Road and Bethel Island Road, nine smaller neighborhood parks scattered throughout the southern end of the project site, and the 200 foot wide power line easement which traverses a portion of the southern end of the project (see Figure 3.9-3). The community park would be approximately 22.4 acres and would contain baseball diamond(s), soccer/football field(s) as well as other recreational amenities. 3-183 a[1i80 pue puvl paaalaBuO ;aoanoS soaroad sil eay ajoSola pua ueTalsapad posodoad Hnzo xas>1noo wn2H V saxrl SSaadxo 'OV l'0 '�V i►'Z 00 ► oV 9"0 � I oV To I 'OV 9'0 'oV 6'Z I I! �I Havd 0I18nd 'OV tr'ZZ i OT i �( 11\� It i I I I .VAUW, II \ r \ \ YAC , ' •� \ 7fllOHil'Cl 1 I 1 JV (Sa3H10 A8) IN3ISAS i t H1Vd/llVai Ol N01103NNOO 3aolnj 1 � I (13381S-NO) AVM 3>118 ------ t;»�.�•� _ •: 1.? (133a1S-330) I Hl V d/l IV al Norm W ••••••••••••-•• � 1 11V81 NVI8lS303d I I -8 3N18 ivnld3ONOO -'-'-'- I I � I 800IN800 30VdS I N3dO ivnid3ONOO I i I I � I � I ' The community park would be located partially under the 200 foot wide power line easement. In general, this use under the power line easement would be acceptable. However, intensive recreational uses such as the baseball diamond, soccer fields and playground areas ' should be located outside the power line easement for safety reasons (see Section 3.11 for additional discussion). Uses within the power line easement should be passive turf areas and landscaping. The community park is proposed to be constructed by the project applicant and offered for dedication to the County who would then be responsible for maintenance of the park. The nine smaller parks are scattered throughout the southern end of the site and range in ' size from 0.1 to 3.0 acres. Uses at these parks would primarily be passive recreation with turf areas, landscaping and benches or other amenities. These smaller parks would be constructed by the project applicant and maintained by the homeowner's association. The 200 foot power line easement would also be as developed ark land. Uses in the area P P ea would primarily be passive recreation with turf areas and landscaping. The project applicant would install the turf areas and landscaping and the homeowner's association would maintain it. The location of the proposed park land is consistent with the Local Parks Map of the Open Space Element. The proposed project also includes hiking and bicycling, trails as shown in Figure 3.9-3, which is consistent with the trail plan in the County General Plan. The following describes how the project conforms to the conceptual trails identified in County General Plan. 1) A potential equestrian/bicycle/hiking trail is designated along the existing drainage canal which traverses the project site from east to west. The project proposed a bicycle/pedestrian trail (also for golf carts) along the primary drainage channel on the project site ("main drain"). This trail would connect to the major trail along the levee system. 2) Major off-street trails and paths are designated along Bethel Island Road, the newly ' constructed portion of Cypress Road and a new roadway that will travel through the project site in a north-south direction. The project proposes on-street bicycle ways along the newly constructed portion of Cypress Road and the new roadway that will that would travel through the project in a north-south direction connecting to Sandmound Boulevard on the north. These bicycle ways would connect to the major trail along the levee system. ' The proposed project would also provide a major trail, consisting of an 8-foot paved path along the top of the proposed internal levee system which would encircle the project site. The General Plan calls for an equestrian/bicycle/hiking trail along the existing drainage channel ("main drain"). Equestrian use along the open space corridor would pose a safety ' problem because of the golf course which is proposed along much of this area. In addition, the type of housing proposed on the project site would not allow the boarding of horses. 3-185 The proposed trail in this area would allow pedestrian/bicycle and golf cart uses. For these ' reasons, equestrian use of the trail along the main drain is not proposed. The off-street trail along the top of the proposed levee system would provide a substantial ' trail facility for project residents as well as residents in the project vicinity. Some residents have expressed concern regarding privacy from trail users because of the elevated nature of the trail. This impact is not considered significant because there are. only a few residences in areas t adjacent to the proposed levee and these residences are located in most cases; several hundred feet from the levee trail. Day Care Center ' The need for day care centers is constantly growing especially in residential communities. ' Ideally, parents would like their children to be cared for close to home or close to work. In response to this concern and the concerns of Contra Costa County for day care, the proposed project has allocated 0.5 acres for such a center. Ultimately the site would be sold or leased to a professional and experienced group to construct, operate, and maintain the center. Maintenance ' If maintenance of the proposed public park is performed by the County, there could be a slight, but not significantly adverse impact to the County. Maintenance of the proposed lakes and swim and tennis/beach club would be by the Homeowners' Association. Maintenance of the golf course would be contracted out to a professional management company,paid for by revenues ' from golf sales and rentals. From a maintenance standpoint, no adverse impacts from the proposed lakes, swim and tennis/beach club or golf course would occur. Relationship to the General Plan , The proposed project would be generally consistent with the goals and policies of the ' County pertaining to the development of parks and recreational facilities. Bethel Island Area The General Plan provides for an off-island bonus residential area(Hotchkiss Tract)which , provides higher density residential development for projects which include substantial recreational amenities (such as the proposed Cypress Lakes project). Such amenities may include marina's or landing facilities; sailing/boating clubs; a lake community; an equestrian or rodeo facility; or 1 tennis club or golf course. Therefore, build-out of the planning area will result in the provision of significant recreational opportunities for both local and County residents. 3-186 MITIGATION MEASURES The proposed project would have a beneficial impact on parks and other recreational ' facilities consistent with General Plan park maintenance policies. The following-mitigation measure is proposed to ensure adequate maintenance of park facilities: ' 3.9-9 The project proposes to construct and dedicate the large community park to the County which would then be responsible for continued maintenance of the park. If this is unacceptable to the County, funding for maintenance of the community ' park should be provided through a special district. (Responsibility: Project Applicant) The following mitigation measure is proposed to ensure the design of the community park reduces potential conflicts with the power line easement: ' 3.9-10 The community park should be designed so that active recreational use areas are located outside the power line easement. Active uses to be located. outside the easement include: baseball diamonds, soccer fields and play ground areas. Uses permitted within the easement should be passive recreation and landscape areas. (Responsibility: Project Applicant) ' The proposed project would allocate 0.5 acres for a day care center. In order to ensure that the future facility to be located on this site is adequate to serve the demand generated by the ' proposed project, the following mitigation measure is proposed: 3.9-11 The project applicant shall prepare a child care needs assessment based upon the ' projected demographics and density of the proposed project. The needs assessment shall be submitted to the Community Development Plan prior to approval of the final phase map for the portion of the protect which includes the day care site. (Responsibility: Project Applicant) Implementation of the mitigation measures discussed above would reduce the project's impact on park facilities to a less-than-significant level. OTHER GOVERNMENT SERVICES: MOSOUTTO ABATEMENT DISTRICT EXISTING SETTING The Contra Costa Mosquito Abatement District maintains an extensive mosquito control program in the project area. Nearby Bethel, Jersey and Holland Islands have historically had extensive mosquito problems,especially in the springtime following winter rains. The high water ' table on these islands, as well as other environmental factors, such as existing wetlands, contribute to this problem. (better from Contra Costa Mosquito Abatement District,dated March 9, 1992.) 3-187 IMPACTS ' The Contra Costa Mosquito Abatement District (CCMAD) notes that the environmental conditions in the area indicate that the project would cause an increase in the level of service ' required from CCMAD. Golf courses and parks typically have water detention basins and possible use of reclamation water within.their boundaries. The detention basins, along with the proposed 60 acres of channels and lake on the project site can lead to mosquito problems year ' round. In addition, residential development adjacent to existing agricultural operations creates problems with urban runoff. New development in the project area would increase the monitoring required to avoid the seasonal emergence of large numbers of pasture mosquitoes, which ' otherwise could annoy area residents and affect human health. (Letter from Contra Costa Mosquito Abatement District, dated Mar. 9, 1992.) The Contra Costa Mosquito Abatement District CCMAD recommends that it be Q (CCMAD) consulted regarding the creation of any new wetlands in the project area. Ponds and lakes should be as deep as possible with steep sides to the embankments to minimize mosquito production. The water level should be kept as constant as possible to avoid production of floodwater mosquitoes. Whenever possible, emergent vegetation should be minimized to reduce protective ' and nutritive habitat for immature mosquitoes. Channels and basins should be as deep as possible with steep sides. CCMAD should be consulted regarding any improvements to existing drainage ditches or the creation of new ones. If water reclamation alternatives are considered ' for recreation areas within the project boundaries, CCMAD should be consulted in the design and testing of alternative methods and disbursement sources. (Letter from Contra Costa Mosquito Abatement District, dated Mar. 9, 1992). ' The proposed design of the Lake and channels and the proposed water quality management plan addresses many of the concerns of CCMAD to help reduce potential mosquito , populations. (See Section 3.7 for additional discussion of the proposed water quality maintenance plan). The proposed design of the lake and water quality maintenance plans would reduce potential impacts from mosquitos to a less-than-significant level. ' MITIGATION MEASURES 3.9-12 CCMAD should be provided the final design plans for wetland mitigation areas ' and golf course maintenance and irrigation for review and,comment prior to their approval. (Responsibility: Contra Costa County) ' 3-188 ' 3.10 UTILITIES This section of the EIR addresses the provision of various utilities for the proposed project ' including: water, sewage disposal, electrical service, natural gas, telephones, solid waste and lighting. This section also addresses applicable policies from the Contra Costa County General Plan, including key growth management issues. Policies are presented under "Existing Setting'; t the evaluation of the project's consistency with these policies is described under "Impacts." Where impacts have been quantified on the basis of the number of residential units proposed by the project, the figure of 1,330 units has been used. The actual net number of additional units ' on the project site would be 1,322 after deducting the eight existing residences on the site that would be removed by the project. Therefore, the following analysis depicts a "worst-case" scenario. ' WATER ' EXISTING SETTING Proiect Site, Water Facilities and Use ' The project site is currently irrigated with delta waterrovided b Reclamation District P Y 799 (RD-799). The few homes that exist on the property utilize groundwater wells and individual pressure tanks. There is no duly organized water purveyor providing domestic water within the project area. The total amount of groundwater presently used for domestic purposes is estimated at 4,000 gallons per day, while irrigation water use is estimated at 600 acre feet per ' year. ' Existing Facilities in the Project Area Groundwater is the source of all domestic water supply in the Planning Area, with groundwater generally withdrawn from depths between 150 and 350 feet however, some ' shallower wells exist in the area (35 to 40 feet). Most of the wells are private individual wells or privately operated water systems such as the Oakley Mutual Water company located on ' Sandmound Boulevard. Ironhouse Sanitary District (formerly Contra Costa County Sanitation District No. 15)publicly operates three water systems. The Contra Costa Water District(CCWD) receives water from Rock Slough. ' Approximately 21 privately operated water companies supply water to as few as two and to as many as 160 customers. There are also an unknown number of private individual wells which supply water to other residences. (See Figure 3.10-1) The distribution systems for the various water systems typically consist of a pump, hydropneumatic tank, and small diameter mains. Fire flows throughout the area are substandard. Water for fire fighting is mainly ' provided by tanker trucks and by pumping from the surrounding sloughs. (See Section 3.9) 1 3-189 Franks Tract aw.a..w„+.A.... a Franks Tract 1 OWN aOgl a A~ j`- Beacon west ° �,•' :' /,, ' t ; Development x".b,out Road Willow Mobile Home Park _ Bethel Island •�a �'�°• �A. et Jersey �` '•e, IslandCatzaaape ' • r Rwa. `'�= Saed'La' •� 1 cRauch La. Dutch Slaaah •• Boa 1 f �✓ S i Duub W b'toad Roi° ell$Road } a WillowPark Drina • i •- ; = Condominium Development `NI; 1 Holland Tract # C `»�''• ;�� Project Site i Y Cf naa Read ; 1 cj `4 1 at' , CO I •.G �:.• . , 4 n Figure 3.10-1: CYPRESS LAKES & COUNTRY CLUB Existing Water Wells and Facilities PROJECT within the Project Area 3-190 ' In the East County area, the Contra Costa Water District (CCWD) provides raw (untreated) water to the Cities of Antioch and Pittsburg, and to the Oakley Water District and West Pittsburg (private company). CCWD obtains its water from the Contra Costa Canal, which ' is part of the Central Valley Project. Water for the canal is diverted from the Delta at Rock Slough. CCWD operates the Contra Loma Reservoir (storage capacity 2,095 acre-feet) and the Martinez Terminal Reservoir (capacity 268 acre-feet). Virtually all of the domestic water used ' within the County by these agencies is from the Delta. The Randall-Bold Water Treatment Plant, constructed under a joint powers agreement ' between the OWD and CCWD, began operation in July 1992. Phase I is designed to process up to 40 mgd, with 25 mgd of the capacity reserved for the CCWD and 15 mgd reserved for the OWD, and with costs apportioned to the respective districts accordingly. First water deliveries ' are to OWD exclusively. The ultimate capacity will be 80 mgd. (Dennis Pisila, CCWD Utility Planner, personal communication May 5, 1992.) ' The most serious potential water service deficiencies that have been identified in Contra Costa County are found in the area of East County within the Urban Limit Line. The three key issues regarding future water service involve: (1) the logistics of supplying water to the growth ' areas (constructing new pipelines,etc.); (2) identifying which water service agencies will assume responsibility for providing service; and (3) guaranteeing that an adequate supply of water will exist during normal and drought periods. ' Water Service District ' The Bethel Island area is not within the sphere of influence of any water district. (See Figure 3.10-2.) The nearest districts which could feasibly provide water service to the Bethel Island area include: ' The OakleyWater District OWD which serves most of the Oakley area (OWD (OWD) Y purchases raw water from the CCWD). • The Contra Costa Water District (CCWD) which serves a large portion of Contra Costa ' County. • The East Contra Costa Irrigation District (ECCID) which provides agricultural irrigation ' water to a portion of the East County area. • The Ironhouse Sanitary District which serves Discovery Bay and portions of the Bethel Island and Hotchkiss Tract areas. 3-191 �: .i N � •A will ..r , r',r:r:r' rt.,,.��1 Slt�uo4 �r '1 . . � .. ' � '"�• � 1� y < • IaN Y I ' Ld Cd • 111 1 cn ` r ' I ' J Vro) a ,• .�r•.ir'�r�,t�r,�,ll.�rr O !j� I � �J�__.,��\ �� -- Qr _ �' ,,•.,' '� ,}..'• :,III ,.. ... - I . - ... .. ,.: . . . . �� W FA 1 t .o zi {,i�,,. t� i Y I j r t , anu\ r.e eoo•r•�o; r•, �j 11 �� � •� 1 ., r ,,1 \ 1 ' �' '� � •� .GIS '� . � I ' / �^ �'( — '•\' ' � ' �� T � ;1■'`'t r' f4' � It it ..... I e 1 • 1 I" I v �.... X11 I�l� �I � � I I� �I t. �� I.;• ../ �` cr it rif1:t j T l t �';'�'�s'f'';��'►�; ii I I��I�I`I l��t 1.���l `1��� I' � ;= f: ���I' ��. ._. '" j� l ,•,{�,.,{ 1111111 ', �' p ,�sir.j�.',>*P� �a I,F:=1 11!1 I "I 1 111" I ,! I�� i k[ %•{ I � z 1 ' The Bethel Island Area and project site would have to be included in the sphere of influence of either the OWD and CCWD, the Ironhouse Sanitary District or the ECCID before one district could provide water service to the area. The ECCID does not have any specific plans ' for construction of a water treatment plant in this area, but could legally serve the area. The CCWD administers the Central Valley Project supply under contract to the U.S. Bureau of Reclamation. That contract requires all areas served to be annexed into CCWD including areas served treated water by another purveyor such as the Oakley Water District. The Contra Costa LAFCO is the Lead Agency for future reorganization actions involving annexations ' to the Oakley Water District and CCWD, as well as Sphere of Influence actions necessary for annexations to proceed by the Conducting Authority. tGeneral Plan Policies and Growth Management Standards ' The General Plan contains adopted water service goals, policies and implementation measures to assure adequate water supply and quality to serve the projected population. The following excerpts from the Public Facilities/Services Element are those most directly applicable to the proposed project. Project consistency with these policies is discussed under"Impacts" (see page 3-205). ' Water service systems shall be required to meet regulatory standards for water delivery, water storage and emergency water supplies. (Policy 7-16) ' Urban development shall be encouraged within the existing water Spheres of Influence adopted by the Local Agency Formation Commission; expansion into new areas within the Urban Limit Line beyond the Spheres should be restricted to those areas where urban development can meet all growth management standards included in the General Plan. (Policy 7-19) At the project approval stage, the County shall require new development to demonstrate that adequate water quantity and quality can be provided. The County shall determine whether (1) capacity exists within the water system if a development project is built ' within a set period of time, or(2) capacity will be provided by a funded program or other mechanism. This finding will be based on information furnished or made available to the County from consultations with the appropriate water agency, the applicant, or other ' sources. (Policy 7-21) • Water service agencies shall be encouraged to meet all regulatory standards for water quality prior to approval of any new connections to that agency. (Policy 7-22) • Land uses and activities that could result in contamination of groundwater supplies shall ' be identified, monitored and regulated to minimize the risk of such contamination. (Policy 7-25) 3-193 1 • The need for water system improvements shall be reduced by encouraging new , development to incorporate water conservation measures to decrease peak water use. (Policy 7-26) ' • Conditionally approve all tentative subdivision maps and other preliminary development plans on verification of adequate water supply for the project. Such condition shall be satisfied by verification, based on substantial evidence in the record, that capacity within the system to serve the specific development project exists or comparable demonstration of adequate waste water treatment capacity. (Implementation Measure 7-i) ' • Encourage water service agencies and the Local Agency Formation Commission(LAFCO) to annex lands planned for urban development by the General Plan into their service ' areas. (Implementation Measure 7-m) • Encourage water service agencies to require separate service connections and meters , where large quantities of water are used for special purposes such as landscape irrigation. (Implementation Measure 7-p) • Where feasible, include water conservation measures recommended by water service agencies in the conditions of approval for subdivisions and 'other new development. (Implementation Measure 7-r) ' The Growth Management Element further states that project approvals conditioned on (1) or(2) of Policy 7-21 above, will lapse according to their terms if not satisfied by verification that capacity exists to serve the specific project ("will serve letters"), actual hook-ups or comparable evidence of adequate water quantity and quality availability. IMPACTS Estimated Water Requirements , The water requirements for the proposed project would amount to approximately 1.7 million gallons per day (gpd). This can be broken down into 884,150 gpd for domestic use and ' 805,200 gpd for landscaping. Table 3.10-1 breaks down the proposed project's water consumption by land use type and domestic versus landscaping uses. The proposed project is proposing to utilize existing groundwater resources for irrigation ' of the golf course, parks, wetlands, and certain levee areas. The groundwater used for these purposes would be taken from the proposed lake and channel system. As indicated in Table 3.10-1, approximately 805,200 gpd of groundwater would be required for irrigation purposes. Alternative Sources of Water The following discussions address various alternative water sources for the proposed 3-194 ' project. Where applicable, a review of existing capacity and its relationship to project demands is presented. For other alternatives, such as the use of reclaimed water and water conservation, a brief discussion of the feasibility and/or benefits is provided. ' Oakley Water District (OWD) The Oakley Water District is in the process of changing over to purchasing treated water from the Contra Costa Water District (CCWD). The raw water that will be treated by.the CCWD will come from the.Contra Costa Canal with the possibility of some of the supply coming from the proposed Los Vaqueros Reservoir. Under an agreement with the CCWD, the OWD has a 15 million gallon per day (MGD)capacity right in the new 40 MGD Randall-Bold Water Treatment Plant (scheduled to be completed in July 1992) presently being constructed by the CCWD. The t OWD projects its ultimate average day water demand to be 14.2 MGD which is for those lands within the defined LAFCO sphere of influence for the District. Of that 14.2 MGD, 3.1 MGD is known as being supplied from groundwater. The total requirements from the CCWD would therefore be 11.1 MGD (12,434 AF/Y). Service to the Bethel Island area has been discussed by the District in their October 1992 Master Water Plan, but the necessary treatment capacity, transmission facilities, and storage requirements were identified as a developer and/or possible condition of annexation cost. In the subject Master Plan, the Bethel Island area (of which the project area constitutes but a part) was identified to require an ultimate average day water demand of 3.9 MGD based on a per dwelling unit use of 600 gallons per day (GPD), which use is consistent with the present single family dwelling per day use within the District. If this source of supply is chosen, the project area will need to annex to the service area of the CCWD. If the project area chooses to have the OWD operate and maintain a system serving the project, it would also need to be annexed to the OWD. ' Service by a new district would require a number of actions to be undertaken including the firming of a water right to water from the delta (possibly Sand Mound Slough), the ' construction of a water treatment plant, pumping, and storage facilities. In addition, the State Department of Public Health (SDOPH) would require the formation of, or annexation to, an agency that would be responsible for the operation and maintenance of the water works in order to comply.with state law relating to suitable drinking water supplies. This agency could be either an investor owned utility (eg - Mutual Water Company) or a public agency such as a County Water or County Waterworks District. Of significance, however, would be the capital cost of ' the treatment, storage, and pumping facilities that would need to be operational prior to occupancy of any structure built as part of the project. ' Contra Costa Water District Water from the CCWD could be made available to the area if a water treatment plant was constructed to treat the water to drinking water standards, and the requisite pumping and storage facilities constructed. However, as in the case with the OWD, the project area would need to be 3-195 Table 3.10-1 ' Project Water Consumption Domestic Landscaping Water Water Use Area (acres) Use (Qpd) Use (gpd) Single Family ' Residences 239.9 861,350 --- Fire Station 2.0 3,800 --- , School Site 7.4 13,750 --- Beach Club 1.9 3,750 --- Daycare Center 0.5 3,000 --- Roadway ROW 74.6 ---- --- Lakes/Channels 61.0 ---- Parks 33.7 ---- 103,740 Golf Course 170.3 ---- 664,170 Wetlands 8.8 ---- 1,800 Levees 54.6 ---- --- Levee Roads 9.0 ---- --- Drill Sites 10.5 ---- --- Open Space 12.7 TOTAL 685.9 885,650 769,710 ----------------- Source: Unit values provided in the Oakley Water District Master Plan Update, 1991. annexed to the service area of the CCWD. In addition, major capital costs relative to treatment, storage,.and pumping would need to be undertaken prior to any occupancy permit being granted. Raw water would be taken from the Contra Costa Canal at Cypress Road. The projected average annual demand at build-out for the Contra Costa Canal(from where t raw water would be obtained under both the OWD and this scenario), has been estimated by the CCWD as 195,000 AF/Y in critical years, with conservation and utilization of reclaimed water ' reducing that number by 17,800 AF/Y. The relative percentage demand that this project would have on those estimates are 0.48% and 0.52%, respectively. It is apparent that there is a cumulative impact on the CCWD sources of supply by virtue of the project. However, the district has identified in their DEIR/DEIS on the Los Vaqueros project that minor sphere of ' influence changes may be able to be accommodated without compromising the project goals. The proposed project's demand would be considered minor.. 3-196 ' Use of Reclaimed Water The amount of domestic water that would be discharged to the sanitary sewer system is ' estimated at approximately 375,000 gallons per day. This sewage would be pumped to the Ironhouse Sanitary District treatment plant which presently disposes of their treated effluent onto pasture lands. At the present time, there is no program by the Sanitary District to reclaim the treated effluent for use other than as pasture irrigation water. Water Conservation ' The project intends to import approximately 990 AF of treated waterY er year for P domestic use. Since this number is based upon a conservative per dwelling unit use of 600 GPD, the project sponsor plans to practice conservation by installing low flow fixtures and appliances when the project is built rather than retrofitting at some future date. ' Groundwater As stated, groundwater is intended to be used for landscaping irrigation outside the residential areas. The estimated demand of 902 AF/Y is an entirely new demand on the groundwater basin since all irrigation water is now obtained from off-site. The water would be taken from the proposed lake (which itself is groundwater) and would be used within the project. ' The net loss to the groundwater basin would be that water that is normally lost through transevaporation since whatever water that is not transpired by the plants, or evaporated, would return to the basin. Using groundwater as the total source of domestic water supply for this project may contribute to secondary problems such as subsidence, salt water intrusion into the delta aquifers, and general lowering of the groundwater table requiring additional pumping costs to surrounding owners that use groundwater. The use of non-potable groundwater for outside landscaping would lessen the amount of energy and chemicals needed in the' _water treatment process as well as allowing a reduction in the size of pipelines. Treated water that would have gone to landscaping could be used for other developments which would require a higher level of treated water. The Oakley Water District, in response to the project applicant's requests, has issued a letter(dated April 30, 1992) indicating that the Oakley Water District would supply the proposed ' project with water as long as the project meets all district regulations,and specifications (see Appendix F). The District's letter also indicates that the proposed project site is not located within the existing Oakley Water District Service Area and would need to be annexed not only into the Oakley Water District, but the Contra Costa Water District as well. Annexation of the project site into the Oakley Water and Contra Costa Water districts would require approval of Contra Costa LAFCO. 3-197 Annexation Issues , The Oakley Water District appears to be the logical provider of domestic water service to the proposed project for the following reasons: , • The OWD has provided the project applicant with a "Will Serve" letter for the project. The OWD has an agreement with the Contra Costa Water District for 1 • gr a 5 mgd right in the new 40 mgd Randall-Bold Water Treatment Plant. • The OWD projects its ultimate average day water demand to be 14.2 mgd, of which 3.1 mgd is derived from groundwater resources, which is for those lands within the District's Sphere of Influence. Therefore, the OWD would have an available capacity of 3.9 mgd ' after build-out of the District's existing Sphere of Influence. • The proposed project would require approximately 0.9 mgd of treated water which could r be accommodated within the District's remaining capacity. • Service to the project area was discussed in the District's October 1991 Master Water Plan which identified an ultimate water demand for the Bethel Island Area of 3.9 mgd. Issues regarding reorganization of the Oakley Water District Sphere of Influence would ' be the responsibility of Contra Costa LAFCO. Facility Requirements , The project proposes to obtain its domestic water supply from the existing OWD mains located at the intersection of Highway 4 and Cypress Road in Oakley. From that,point, the project would construct two separate 12" pipelines to the main entrance of the project, that are periodically interconnected, to the project site. The 12" pipelines would have sufficient capacity to serve the proposed project as well as some limited additional development in the Bethel Island ' Area. The two separate transmission lines are proposed so that if one line develops a break, the break could be isolated and adequate water flow to serve the project could continue in the other line. This is different than the distribution system identified in the OWD Master Plan which calls ' for a 18" line along Cypress Road to serve the Bethel Island Area. Relationship to the General Plan ' The project would be consistent with the General Plan policies regarding water supply. The proposed project would obtain treated water from the OWD. The transmission facilities would be sized adequately to meet fire flows. The project proposes to construct to separate periodically connected pipelines to the site., This "dual" system is proposed so that if one line breaks, the break could be isolated allowing adequate flows to continue in the other line. This system also eliminates the need for water storage tanks. 3-198 ' The applicant has received a "will serve" letter from OWD indicating that it would serve the project if its regulations and specifications are met (Appendix F). The project proposes to design its facilities consistent with OWD's requirements and to reflect the special Delta ' environment (i.e. water quality). Consistent with the County's Growth Management Standards, the project would fully finance all new water supply improvements. ' MITIGATION MEASURES The following mitigation measure is proposed to monitor effects on the groundwater table as a result of irrigation on-site and to avoid any potential impacts due to groundwater draw down: 3.10-1 Implement a groundwater management plan to address water requirements for irrigating the golf course and parks and to monitor changes in the groundwater table. The groundwater management plan should also address the management of pesticides and measures to be taken to reduce potential impacts on groundwater ' resources. In addition, the plan should identify what areas, and in what sequence, water will be discontinued to portions of the golf course and parks in the event ' of water cutbacks because of drought or substantial lowering of the water table. The plan should be approved by the County prior to filing a final subdivision map. (Responsibility: Project Applicant) ' The following mitigation measures are proposed to reduce the projects' water consumption demand: ' 3.10-2 Design into the golf course the use of grasses that are drought tolerant to limit the amount of water necessary for irrigation. (Responsibility: Project Applicant) 3.10-3 Require all structures to confirm to the California Health and Safety Code Section 1792.3 and the Public Resources Code Section 25402 with regard to maximum ' flow rates through plumbing fixtures. (Responsibility: Project Applicant) 3.10-4 Provide homeowners with alternative landscaping opportunities such as xeriscape landscaping for builder installed front yards. (Responsibility: Project Applicant) 3.10-5 Design water distribution systems in accordance with American Water Works Association standards. (Responsibility: Project Applicant) 3.10-6 Install cathodic protection where corrosive environments are found and metallic ' water line products must be used. (Responsibility: Project Applicant) 3.10-7 Landscaping materials should be drought-tolerant to reduce overall landscape and ' irrigation requirements. The landscape areas should conform with the requirements of the County's Water Efficient Landscape Ordinance. (Responsibility: Project Applicant) 3-199 The following mitigation measure is proposed to ensure that off-site water improvements , necessary to serve the site are provide prior to project construction: 3.10-8 The project should be required to construct, or pay a fee equal to, the necessary t off-site water system improvements to serve the proposed project. The size and design of these facilities should meet all applicable standards and requirements of ' the Oakley Water District and local Fire District Standards. The project should be reimbursed for the cost of constructing facilities which have the capacity to serve future development in the planning area served by the facilities. The necessary off-site water facilities should be completed and operational prior to the first homes being occupied on the site. (Responsibility: Project Applicant) SEWAGE DISPOSAL ' EXISTING SETTING ' Most of the Planning Area is within the Ironhouse Sanitary District and receives sanitary service through a system of collection pipelines, force mains, transmission lines, pumping , facilities and a wastewater treatment plant. Wastewater is conveyed by gravity sewer system with lift,stations and force mains, to the 14-inch transmission force main along Bethel Island Road, and on to the Oakley Wastewater Treatment and Reclamation Facility (Oakley Treatment ' Plant) north of Oakley. (See Figure 3.10-3) The Ironhouse Sanitary District combined several previously separate districts,the Oakley ' Sanitary District, Contra Costa County Sanitation District No. 15 (CCCSD 15), and the Oakley/Bethel Island Wastewater Management Authority, through the following actions: the Oakley Sanitary District was renamed the Ironhouse Sanitary District; the newly named Ironhouse ' Sanitary District then annexed CCCSD 15; the Oakley/Bethel Island Wastewater Management Authority, which up to that time had operated the wastewater treatment plant, was transferred to the Ironhouse Sanitary District. , The Ironhouse Sanitary District, through the Local Agency Formation Commission (LAFCO), is in the process of expanding its Sphere of Influence to annex all lands between the , former Oakley Sanitary District to the west and the former CCCSD 15 to the east, and between the San Joaquin River to the north and Delta Road to the south. -The new boundary may include , the Town of Knightsen. However, the parcels in Hotchkiss Tract which were not included,in the old CCCSD 15 jurisdiction are not included in the Ironhouse Sanitary Districts current application to LAFCO. A separate LAFCO application would be required for these two parcels to be annexed to the district. (Jack Elder, May 5, 1992) , Collection System ' Collection system capacity varies by location within the system. Because a combination of gravity lines, pump stations and force mains are used, capacity is dependent on the system ' 3-200 Franks Tract t \I ' Franks Tract Gad Awe 1 \• � •a �... Bethel Island ' i46 ' Jersey \� i IV \•.. IslandGaleve And �, \ *e otup ! ���{- 1►La Sandy Ll. i _ Main Pump Station Datce Slou{D s'Oe :fI JV Astch ,cu{ VM 14 e41 Rose \,i y• Pump Station r� �i i, a mO •\ i °°e 10 t `L Holland Tract Project Site t r To OBI Treatment Plant ,....__._ . .� . °e c ¢ • . c ' Figure 3.10-3: CYPRESS LAKES & COUNTRY CLUB Existing Sewer Facilities within the Project Area PROJECT 3-201 element or series of elements in the portion of the system most impacted by development. ' A 14-inch sanitary sewer force main conveys sewage from the Main Pump Station, located on Bethel Island, and WEB-14 Pump Station, located at Wells Road and Bethel Island Road, to the sewage treatment plant. Pump station staff indicates a pumping capacity of at least 2.0 million , gallons per day (mgd) from the Main Pump Station, and a combined capacity of 2.4 mgd using both the Main and WEB-14 pump stations. The force main and pumps appear to have available capacity in excess of 1.0 mgd. Flow estimates from the Planning Area average 0.6 mgd, half of r which is attributable to infiltration and inflow and half to raw sewage. Treatment Capacity The Oakley Treatment Plant was designed for a treatment capacity of 1.5 mgd dry ' weather flow, adequate to serve 5,800 persons. Since the plant was put into operation, it has been determined that the actual treatment capacity of the plant is 2.2.mgd, significantly greater than the design capacity, and that the plant has the capacity to serve approximately 13,800 persons. Currently, the plant is treating approximately 1.45 mgd. The plant can be expanded , to serve all forecasted growth within the existing service area. The District has completed a feasibility / preliminary design study for increasing plant ' capacity up to 8.0.mgd in stages. This project is currently undergoing environmental analysis and review. (Jack Elder, May 5, 1992) , Disposal System/Capacity, . The current Waste Discharge Requirements set by the California Regional Water Quality ' Control Board (RWQCB) - Central Valley Region require the District to dispose of all reclaimed water by land disposal; no surface water discharge is permitted. The District's disposal system ' consists of 309 acres of irrigated pasture land owned by the District (this includes the recently purchased Porter Ranch), a 100-acre parcel, owned by a nearby dairy, that can be used for disposal during the winter months) and two storage reservoirs with a combined capacity of 350 , acre-feet (114 million gallons). The District is in the process of looking at additional sites for land disposal. (Jack Elder, May 5, 1992) The plant's disposal capacity is 2.2 mgd based on dry weather flows. Current disposal , requirements are approximately 1.4 mgd. Future expansion of disposal capacity may involve direct discharge of treated water from the treatment ponds to the marsh area near the treatment ' plant; Big Break; or, the San Joaquin River. If the cost of land disposal were comparable to the lowest cost of one of these alternatives, the RWQCB would probably require land disposal, and the District would have to acquire additional rights by agreement with the owners or by eminent , domain. However, the cost of land required for land disposal has increased rapidly and it is unlikely that land disposal through purchase of land-would be comparable to the least expensive surface water discharge alternative. ' 3-202 r ' Funding of Expansion New system connections will pay a Facilities Capacity Fee to provide funding for future ' expansion. This fee is a charge on all new development to replace the capacity used by the development. The current fee per household connection is $2,146.00 for plant capacity, plus $600 for trunk lines,plus $250 per connection. The Oakley Sanitary District and CCCSD 15 had different trunk lines fees and connection charges. These will be consolidated in June 1992. Future development will pay the same fees, adjusted for inflation, in advance of the capacity needed to serve the development. General Plan Policies and Growth Management Standards ' General Plan sewage disposal goals, policies and implementation measures are set forth in the Public Services/Facilities Element. Those most directly applicable to the proposed project include the following. Project consistency with these policies is discussed under "Impacts". • Sewer treatment facilities shall be required too e operate in compliance with waste discharge q P P g requirements established by the California Regional Water Quality Control Board. Development that would result in the violation of waste discharge requirements shall not be approved. (Policy 7-29) • Sewer service agencies shall be encouraged to establish service boundaries and develop treatment facilities to meet future service needs based on the growth policies contained in the County and cities' General Plans. (Policy 7-30) • Urban development shall be encouraged within the sewer Spheres of Influence adopted by the Local Agency Formation Commission. Expansion into new areas within the Urban Limit Line but beyond the Spheres of Influence should be restricted to those areas where urban development can meet growth management standards included in the General Plan. (Policy 7-31) • At the project approval stage, the County shall require new development to demonstrate that wastewater capacity can be provided. The County shall determine whether (1) capacity exists within the wastewater treatment system if a development project is built within a set period of time, or (2) capacity will be provided by a funded program or other ' mechanism. This finding will be based on information furnished or made available to the County from consultations with the appropriate sewer agency, the applicant, or other sources. (Policy 7-33) • For future sewer facilities that may be required, appropriate land areas in the County shall be designated consistent with other policies in the General Plan. (Policy 7-34) r 3-203 • Opportunities for using reclaimed wastewater shall be identified and developed in ' cooperation with sewer service and water service agencies. (Policy 7-35) • The need for sewer system improvements shall be reduced by requiring new development , to incorporate water conservation measures which reduce flows into the sanitary sewer system. (Policy 7-37) • Conditionally approve all tentative subdivision maps and other preliminary development plans on verification of adequate wastewater treatment capacity for the project. Such condition shall be satisfied by verification based upon substantial information in the , record that capacity within the system to serve the specific development project exists or comparable demonstration of adequate wastewater treatment capacity. (Implementation , Measure 7-t) • Include wastewater reduction and other measures recommended by sewer service agencies ' in the conditions of approval for subdivisions and other new development. (Implementation Measure 7-x) • Encourage sewer service agencies and the Local Agency Formation Commission (LAFCO) to annex lands planned for urban development by the General Plan into their ' service areas. (Implementation Measure 7-y) • Encourage LAFCO to establish sewer service Spheres of Influence that are coincident , with the boundary of planned urban development in the General Plan, including those rural areas that currently receive service. (Implementation Measure 7-z) The Growth Management Element further states that project approvals conditioned on (1) or (2) of policy 7-33 above,will lapse according to their terms if not satisfied by verification that capacity exists to serve the specific project ("will serve letters"), actual hook-ups or comparable , evidence of adequate sewage collection and wastewater treatment capacity availability. IMPACTS ' Proiect Saecific The proposed project would result in a significant increase in wastewater generated from the project site. Based on wastewater generation factors provided by the Oakley Sanitary District, the proposed project would generate approximately 360,000 gallons/day (or 0.36 mgd) r based on 270 gallons/unit day x 1,330 units. The most logical provider of sewer service for the project is the Ironhouse Sanitary ' District because 75% of the proposed project site is located within their existing service boundaries. The project applicant has requested that the remainder of the project site be annexed 3-204 r to the Ironhouse Sanitary District. The project applicant has received a "will serve" letter from the Ironhouse Sanitary District (see Appendix G). Annexation of the remainder of the project site into the Ironhouse Sanitary District would require approval from Contra Costa LAFCO. The sewage disposal system for the project would consist of gravity sewer mains, lift stations and pumps. Wastewater from the system would be discharged into the existing force ' main in Bethel Island Road at Cypress Road. The existing force main in the project vicinity appears to have adequate remaining capacity to serve the proposed project (available capacity is approximately 1.8 mgd,project would generate approximately 0.36 mgd). However, the existing ' force main is cast-iron which has caused problems in the past. Therefore, a hydraulic analysis of the force main may be necessary prior to any increase in sewage generation from the project area (Jack Elder, June 3, 1992). There also appears to be adequate treatment and disposal capacity at the treatment plant to serve the project (available capacity is approximately 0.75 mgd, project would generate 0.36 mgd). However, the District provides service on a first-come/first- serve basis which is determined at the time building permits are issued. Bethel Island Area COLLECTION Projected average daily flow at full build-out of the Planning Area would be 1.61 mgd. The resulting peak hourly flows would be 3.3 mgd. An analysis of the gravity and pressurized elements of the collection system would be required to fully evaluate impacts. The existing force ' main appears to be adequate for this flow rate, although new pumps or new pump stations may be required. The Main and WEB-14 pump stations have a combined capacity of 2.4 mgd. The flow is conveyed from the pump station to the treatment plant through a 23,500-foot long 14-inch ' diameter force main. Additional pumping in the Main pump station and the WEB-14 pump station would need to be provided to accommodate build-out under the County General Plan. The head loss through the 14-inch force main at a flow of 3.3 mgd would result in head/pressure ' losses of approximately 50 pounds per square inch (psi). Assuming a 150 psi rating for the existing line, the 14-inch line would be adequate. ' TREATMENT The treatment plant was designed for a peak month design capacity of 1.5 mgd. Actual ' plant operations analyses have shown that the plant has a peak month design capacity of 2.2 mgd. Current disposal capacity is in excess of 2.2 mgd based on dry weather flows. The peak month flow for the Planning Area at build-out (including Oakley flows and existing flows) using a ' peaking factor of 1.15 is 13.0 mgd. This would require expansion of the existing treatment and disposal capacities upon build-out under the County General Plan. 3-205 Relationship to the General Plan The applicant received a"will serve"letter from the Ironhouse Sanitary District(Appendix G). The District will provide service if the sewage facilities necessitated by the project are consistent with.its regulations. The applicant will pay all general connection facility capacity trunk line and household connection fees consistent with the District's requirements and the County's Growth Management Standards. MITIGATION MEASURES The following mitigation measures are proposed to ensure adequate sewage collection facilities are provided to accommodate the project: On-Site Improvements 3.10-9 The project applicant would be required to construct all necessary sewage collection facilities on-site to serve the project. These facilities should be built to district standards and appropriate easements for district maintenance provided. The sewage collection facilities should be installed prior to the first homes being occupied. (Responsibility: Project Applicant) Off-Site Improvements 3.10-10 A hydraulic analysis of the force main should be conducted to determine the capacity of the existing force main and any improvements that may be necessary to accommodate the proposed project. This analysis should be conducted prior to approval of the project's final subdivision map. The project shall pay its fair share of any improvements necessary to the force main to serve the project. The fair-share fee shall be paid upon -approval of the first . phased map. (Responsibility: Ironhouse Sanitary District/Project Applicant) 3.10-11 Theproject should be required to pay the full costs of any increase in pumping capacity or new pump station(s) necessary to serve the project. The need and cost for these improvements shall be determined by the Ironhouse Sanitary District prior to approval of the final map. (Responsibility-. Project Applicant) 3.10-12 A reimbursement agreement shall be entered into between the project applicant and the Ironhouse Sanitary-District whereby the project applicant would be reimbursed for the portion of the cost of new facilities which have the capacity to serve areas in addition to the project. The reimbursement would be paid out of fees paid by future developments. (Responsibility: ProjectApplicant) 3-206 ' ELECTRICAL SERVICE EXISTING SETTING Electricity is supplied to the Bethel Island area by the Pacific Gas and Electric Company (PG&E). Power is supplied from the regional power grid, which is fed by various power ' generating facilities throughout the western states. The Vaca-Dixon Station near Vacaville distributes electricity to various substations, which supply power to local distribution networks. The Bethel Island and Hotchkiss Tract areas are currently served by the Contra Costa Substation in Antioch. Power is transmitted over two parallel 21 kV lines along Cypress Road. There are four transformer banks, three on Bethel Island and one south of Dutch Slough, which step down the voltage from 21 kV to 4 kV. Power is supplied to individual units via overhead lines. ' General Plan Policies and Growth Manaeement Standards iThe General Plan proposes, in various Elements, specific policies related to electrical services. The following policies are pertinent to development within the Planning Area. Project consistency with these policies is discussed under "Impacts" (see page 3-216). • Development of all urban uses shall be coordinated with provision of essential community services and facilities including, but not limited to roads, law enforcement and fire protection services, schools, parks, sanitary facilities, water and flood control. (Policy 3-6) ' Consolidation of utility/drainage/transportation corridors shall be considered, where appropriate. (Policy 5-31) • The County shall encourage housing that will conserve and more efficiently use energy resources. (Policy 6-5) ' New development shall be required to pay its fair share of the cost of all existing public facilities it utilizes, based upon the demand for these facilities which can be attributed to tnew development. (Policy 7-1) • New development, not existing residents, shall be required to pay all costs of upgrading ' existing public facilities or constructing new facilities which are exclusively needed to serve the new development. (Policy 7-2) ' New power lines shall be located parallel to existing lines in order to minimize their visual impact. (Policy 8-98) ' The appearance of the County shall be improved by eliminating negative features such as non-conforming signs and overhead utility lines, and by encouraging aesthetically designed facilities with adequate setbacks and landscaping. (Policy 8-105) 3-207 IMPACTS Electric service would be supplied to new development by PG&E. The proposed project may result in the need to reinforce (add additional capacity to) the parallel 21 kV distribution lines from east of Sellers Avenue to Bethel Island. Typically, the cost . of reinforcing existing lines would be borne by PG&E. The project site would be served by new and reinforced 21 kV underground distribution lines. The costs associated with off-site distribution line reinforcement and new line.and equipment installation would be financed by both the developer and PG&E, according to Public Utility Commission (PUC) regulations. Underground utilities installed in areas subject to flooding and higher salinity levels should be placed in relatively water resistant conduits and vaults this in order to maximize the cable life. Cables which are presently being installed have life spans of up to 20 or 30 years. As part of their normal planning process,PG&E would conduct a study to determine the extent of reinforcement and need for additional equipment and new lines. Relationship to the General Plan The project would be consistent with the General Plan. The applicant proposes to install all new electrical service lines underground in water tight conduits according to PG&E Standards at it's expense. MITIGATION MEASURES The following mitigation measure is proposed to ensure the project conforms with the requirements of the General Plan. 3.10-13 The project shall include the undergrounding of all new electrical service lines necessary to serve the project site. Electrical lines should be placed in relatively water tight conduits according to PG & E standards. This should be completed prior to the first houses being occupied. (Responsibility: Project Applicant/PG&E) 3.10-14 The need to upgrade off-site electrical lines shall be determined by PG&E prior to approval of the final map. If off-site reinforcement is necessary, the project applicant should be required to pay the project's fair-share, if any, of the reinforcement. (Responsibility: Project Applicant) 3-208 ' NATURAL GAS SERVICE EXISTING SETTING A natural gas distribution system for residents does not exist in the Bethel Island.Area. Gas service to individual units is provided by propane tanks. ' The Bethel Island Area contains significant natural gas resources. There are approximately 22 natural gas wells operating in the area, three of which are on Bethel Island. ' None is located in the Hotchkiss Tract. The gas produced by these wells is conveyed through a system of collector lines to a main trunk line in Antioch, where it becomes part of PG&E's regional gas network. Five potential drill sites for natural gas, occupying 10.5 acres, are located ' within the project boundaries but outside the proposed levee system. These drill site areas are not proposed for development at this time. Issues related to natural gas production and the drill sites on the project site are discussed in Section 3.11 of this EIR. IMPACTS The Cypress Lakes project proposes all electric service to the site, with individual homeowners having the option of using propane tanks. iThe five drill sites shown within the Cypress Lake boundaries could have potential impacts, on adjacent residences if the drill sites become operational. Issues regarding the development of natural gas wells adjacent to the proposed residential uses are discussed in Section 3.11 of this EIR. MITIGATION MEASURES The proposed project would have minimal impact on natural gas service because it would ' be served by electricity only. If desired,individual project residents could use propane if allowed by the homeowner's association. No additional mitigation necessary. ' TELEPHONE SERVICE EXISTING SETTING Telephone service in the Bethel Island Area is provided by Pacific Bell. The existing system consists of an underground fiber trunk line which runs along Cypress Road and Bethel Island Road, to the central office located on Bethel Island. The trunk line feeds the switching equipment, which is located in the central office. Feeders run from the central office and provide phone service to discrete sections of the Bethel Island area. The feeders interface with local ' distribution systems which supply individual units via overhead lines and poles. The phone system serving the area south of Dutch Slough (Hotchkiss Tract) has capacity for approximately 3-209 i 1 500 additional connections. Bethel Island's phone system has adequate capacity to accommodate ' the existing growth rate of approximately 80 new connections per year. General Plan Policies and Growth Management Standards ' Various Elements of the General Plan contain the following policies which can be applied to telephone services for development within the Planning Area. Project consistency with these ' policies is discussed under "Impacts" (see page 3-219). • Development of all urban uses shall be coordinated with provision of essential community ' services and facilities including, but not limited to roads, law enforcement and fire protection services, schools, parks, sanitary facilities, water and flood control. (Policy 3-6) • Consolidation of utility/drainage/transportation corridors shall be considered, where ' appropriate. (Policy 5-31) • New development shall.be required to pay its fair share of the cost of all existing public facilities it utilizes, based upon the demand for these facilities which can be attributed to new development. (Policy 7-1) • New development, not existing residents, shall be required to pay all costs of upgrading existing public facilities or constructing new facilities which are exclusively needed to serve the new development. (Policy 7-2) • The appearance of the County shall be improved by eliminating negative features such as non-conforming signs and overhead utility lines, and by encouraging aesthetically designed facilities with adequate setbacks and landscaping. (Policy 8-105) IMPACTS ' Proiect Specific The proposed Cypress Lakes project would require the replacement of the switch on ' Bethel Island and the extension of new telephone cables to the project site. The proposed project would probably require a minimum of 1,330 new residential connections, plus connections for , the proposed recreational uses as necessary. In addition, the use of facsimile machines and personal computer modems would increase the demand for new connections beyond that historically required for the proposed uses. According to PUC regulations, costs of line and ' equipment installation would be borne by the developer and Pacific Bell. According to County policy, distribution lines would need to be placed underground in relatively water tight conduits , and vaults, thereby avoiding visual impacts and prolonging the life of the equipment and cables. 3-210 Bethel Island Area The switch at the Pacific Bell's central office on Bethel Island has capacity for approximately 2,200 additional connections. Modification or replacement of the switch would therefore be required for build-out of.the Planning Area. It would be necessary to extend new telephone cables to Hotchkiss Tract once the 500 connection reserve is exhausted. Cost responsibility for upgrading the switch and extending the cables is governed by the Public Utilities Commission. Telephone cables must be installed in relatively watertight conduits and vaults in order to extend their life. Relationship to the General Plan ' The project would be consistent with the General Plan. The applicant will finance all costs of upgrading the existing communications system as discussed above. Moreover, the applicant will coordinate its development plans with Pacific Bell, place all distribution lines underground, and install telephone cables underground. MITIGATION MEASURES The proposed project would have minimal impacts on telephone service. The need for P P J P P additional telephone/communication facilities would be funded by typical hook-up and uses fees ' assessed on individual homeowners. However, to ensure the proper expansion and design of telephone facilities, the following mitigation measures are proposed: ' 3.10-15 Place distribution lines underground. (Responsibility: Project Applicant/Pacific Bell) 3.10-16 Install telephone cables in relatively water-tight conduits and vaults. (Responsibility: Project Applicant/Pacific Bell) ' No additional measures are identified at this time. SOLID WASTE EXISTING SETTING ' In Contra Costa County solid waste collection and disposal has been the responsibility of private companies. The role of government in solid waste management is one of planning, administration, and facility approval. Approximately 750,000 tons per year of solid waste is generated by residences, businesses and industries in the County. The County's landfill capacity was expanded with the approval of the Marsh Canyon and Keller Canyon Landfills. Refuse ' collection service in the Planning Area is provided by Oakley Disposal Service. 3-211 Bethel Island and Hotchkiss Tract generate approximately 75 to 100 cubic yards of ' compacted waste per week. Oakley Disposal currently operates one truck, three days per week, to service this area. The area was previously served by Brentwood Disposal, however growth in the area necessitated opening a second office in Oakley. Both Brentwood Disposal and Oakley Disposal are under the same ownership. (Gloria Gonzales, May 6, 1992) Refuse from the project area is transported to the Acme Waste Recovery and Transfer Station in Martinez where resource recovery and recycling operations for this part of the County are located. After separation, the remaining refuse is then transported to the Keller Canyon Landfill near Pittsburg. In accordance with County solid waste policy, all refuse must be initially transported to transfer stations. This requirement is also included in the conditions of approval for development projects. (Ray Malone, May 7, 1992) Refuse from the Bethel Island Area was formerly transported to the Contra Costa Sanitary Landfill in Antioch, however this site was closed on March 31, 1992. In the future, plans are to transport solid waste from the East County area to a new transfer station, the East County Community Collection Center, proposed to be located east of Antioch on Wilbur Avenue. This project is undergoing environmental review; the estimated completion date for the facility, if approved, is 1994. (Ray Malone, May 7, 1992) General Plan Policies and Growth Management Standards ' In order to provide adequate and effective solid waste disposal services in keeping with the growth management objectives of the General Plan, a comprehensive set of county wide goals, policies and implementation measures were adopted. The following excerpts from the Public Services/Facilities Element are the goals, policies and implementation measures which could be applicable to private development projects. Project consistency with these policies is discussed under "Impacts" (see page 3-222). • To provide for the safe, efficient and cost-effective removal of waste from residences, businesses and industry. (Goal 7-AE) • To reduce the amount of waste disposed of in landfills by: , 1) reducing the amount of solid waste generated (waste reduction); 2) reusing as much of the solid waste as possible (recycling); ' 3) utilizing the energy and nutrient value of the solid waste (waste to energy and composting); and 4) to properly dispose of the remaining solid waste (landfill disposal). (Goal 7-AG) • To divert as much waste as feasible from landfills through recovery and recycling. (Goal 7-AH) , 3-212 1 ' Solid waste disposal capacity shall be considered in County and city land use planning and permitting activities, along with other utility requirements, such as water and sewer service. (Policy 7-89) Since the adoption of the General Plan, the County adopted a Solid Waste Management Plan (Dec. 1989). However, this plan was preempted by AB939 on Jan. 1, 1990, mandating that new plans be formulated. The County is in the process of preparing a new plan, but is using the Dec. 1989 plan for guidance. The Dec. 1989 plan contains no project-specific policies, but the new one may address source reduction and recycling. (Ray Malone, Community Development Department, personal communication May 5, 1992) IMPACTS Proiect Specific The proposed Cypress Lakes project includes 1,330 new dwelling units. This would increase the population by about 3,247 residents and would generate about 13,213 pounds of additional solid waste per day, a rate of 4.1 pounds per person per day (Contra'Costa County Solid Waste Management Plan, December 1989). This quantity would contribute to the cumulative impact of solid waste disposal for the population in the East County area. Development of the Cypress Lakes project would require expansion of the service routes and possibly necessitate an additional truck and driver. However, the cost of expanding services to serve the project site would be paid for through normal collection fees. (Gloria Gonzales, May ' 6, 1992.) Bethel Island Area Generation of additional solid waste by new development in the Bethel Island Area would require modification of the existing refuse collection service. Oakley Disposal Service would ' need to expand its routes and add additional equipment and personnel. The 3,109 new dwelling units allowed by the County General Plan would generate a population 7,190 persons, assuming 2.57 persons per household and a 10 percent vacancy rate. This amounts to about 29,500 pounds of new waste generated per day at build-out of the Planning Area. Relationship to the General Plan The project would be consistent with the policies contained in the County General Plan. Roadways are designed and would be constructed to provide adequate access for collection trucks. 3-213 1 ' 1 MITIGATION MEASURES , The proposed project would not result in an adverse impact on solid waste collection and disposal services, therefore no mitigation measures are proposed. , Although the County's adopted Solid Waste Management Plan was preempted by AB 939, the plan is being used.by the County for guidance. In addition, the new solid waste plan, now in progress, may address source reduction and recycling requirements that would be appropriate to include in the conditions of approval for the proposed Cypress Lakes project. LIGHTING EXISTING SETTING ' Very little street lighting exists in the Planning Area, particularly in the Hotchkiss Tract portion. Street lighting in public streets, or streets intended to become public streets,would be installed in accordance with the Contra Costa County Code (Title 9: Subdivisons), summarized below: • Following approval of the tentative map, the subdivider shall submit construction plans , for the street lighting improvements. • All street lighting systems shall be jointly owned and operated by the county and the serving public utility company; unless other adequate arrangements are approved by the .planning commission. Costs for ornamental street lighting standards or costs associated , with any underground wiring system are not the responsibility of the county or utility company. • If the subdivision is not within the boundaries of a county service area authorized to , supply street lighting, annexation to the appropriate county service area is required. • The public works department may require upgrading of existing or proposed lights at , intersections where deemed necessary to prevent a hazard to traffic or pedestrians. Street lighting shall be provided along all streets within one mile of schools. IMPACTS ' The proposed Cypress Lakes project includes street lighting and additional lighting associated with individual residential units and recreational uses. The street lighting would be ' installed in accordance with Contra Costa County Code (Title 9) requirements. 3-214 ' The project applicant proposes that the street lights be maintained by Contra Costa County. County code requires that a one year deposit be made to the public works department for maintenance and adjustments to the street lighting. ' Street lighting associated with the project may result in urban "glow" which may impact the visual character of Hotchkiss Tract. This potential impact would be significant. MITIGATION MEASURES Street lighting on public streets would require annexation of the proposed Cypress Lakes project to a county service area for this purpose. The following mitigation measure is proposed: ' 3.10-17 Project street lights should utilize down focused lights and other features to reduce glare. The design of street lights should be submitted for review and approval to the County Public Works Department for review and approval prior to approval rof the final map. (Responsibility: Project Applicant) Implementation of this measure would reduce the project's glare impacts to a less-than significant level. 1 _ 3-215 3.11 HUMAN HEALTH EXISTING SETTING Development of residential and recreational land uses on the project site resents certain ' P P J P concerns regarding potential adverse effects on human health. Potential hazards may exist on the project site due to the past and present agricultural use of the property (hazardous materials in the from of pesticides), nearby agricultural operations, the presence of electrical transmission lines, natural gas wells in the project vicinity, mosquitos and their potential to transmit diseases, and the project site's location (down wind) of various industrial uses in the Antioch area. The following discussion describes existing conditions in each of these areas. Hazardous Materials , Past and present use of pesticides is the primary hazardous material concern related to the project site. The number and type of pesticides that are legal and thought to be safe has changed significantly over time. For example, DDT, which once was legal in the United States, is now illegal to use due to its considerable adverse effects on the environment. Because of the long history of agricultural uses on the project site, it is assumed that a wide range of pesticides have been used on the project site (including those that were legal, but may now be illegal). Many agricultural chemicals degrade naturally, either by sunlight-degradation, biological and/or chemical decomposition, oxidation, or volatilization. The rate of degradation ranges widely. Some agricultural chemicals can move up the food chain from plants to animals such ' as birds and fish and ultimately to humans. However, the health risks associated with many pesticides are unknown. Long-term agricultural use of a property can tend to concentrate, or build-up, pesticides in the soil. The pesticides of most concern are those that do not easily degrade and are toxic or carcinogenic. County regulations require that "restricted-use" pesticides be stored in storage areas that , are locked and posted with warnings. Because of these restrictions, pesticides are generally stored in the same location year after year and can result in these storage areas being contaminated. , A preliminary environmental assessment for hazardous materials was conducted on the project site in 1989 by Kaldveer Associates. The purpose of this investigation was to identify any conditions or activities on the site or in the site vicinity that may result in or indicate the presence of potentially hazardous materials at the ground surface or in the soil. The information in this section of the EIR is summarized from the Kaldveer Associates Report which is available , for review at the offices of the Contra Costa County Community Development Department. As part of this preliminary assessment a site reconnaissance was conducted, county and , state government agencies were contacted and available documents were reviewed. The research focused on the present and past uses on the site which may have involved the use of hazardous 3-216 materials. The preliminary assessment found that there was no evidence of any soil and/or groundwater contamination or underground storage tanks existing on the property. However,due to the past and present use of the site for agricultural purposes, there is the potential for the existence of low levels of residual pesticides in the soil. Several above ground fuel storage tanks are located on the project site near the Dal Porto residence. In addition, four vehicles are also stored on the property. The surrounding properties, primarily to the north, west and south, support some form of agricultural operation. These agricultural operations are similar to those presently and historically found on the project site (cattle grazing, seed crops, row crops). Pesticides are regularly used on the surrounding properties. Aerial application of pesticides is often used on row crops. Aerial ' application of pesticides can expose agricultural workers and `nearby residents to hazards. However, application is restricted to certain wind and weather conditions to minimize drifting of pesticides across property lines. County regulations also require that the pilot maintain a 100- foot buffer zone between any building and the application area. Electrical Transmission Lines Electric power lines and other electrical devices that utilize alternating current produce electromagnetic fields which are created by the electric charges flowing through the electrical transmission lines and devices. The strength of these fields varies greatly from large, high- voltage power lines, which create strong electromagnetic fields, to household appliances which create low frequency electromagnetic fields. Numerous studies of human populations (epidemiological studies) have been performed to look for associations between exposure to electromagnetic fields produced by power lines, household wiring, electrical appliances and various diseases such as cancer, birth defects, developmental abnormalities and various neurological effects. Some of these studies have found a statistical association between increases in exposure to electromagnetic fields and increased cancer rates. However, epidemiological studies only show a statistical association and do not prove that electromagnetic fields are involved in causing cancer. Other research and studies performed to date are not conclusive on the potential health affects of electromagnetic fields. Due to the inconclusive nature of past studies, only seven states have adopted regulations to limit the intensity of electric fields in transmission line right-of-ways. These include Montana, Minnesota, New Jersey, New York, North Dakota, Oregon, and Florida. The state of California does not have any standards for exposure to electric or magnetic fields or siting criteria for residential development near power lines. The California Department of Education has adopted guidelines that recommend minimum distances between new schools and the edge of transmission lines right-of-way. The setback guidelines are 100 feet for 100-110 kV lines; 150 feet for 220- 230 kV lines; and 250 feet for 245 kV lines. 3-217 1 The project site contains several large transmission lines and an easement for a future transmission line. Three electrical transmission lines are located through the south-west corner of the project site. These include two PG&E power lines (both 500 kV) and one USA power line (230 W). The 230 Kv USA power line is slated to be removed in the near future. The project site also includes a 200 foot wide easement for a future Western Area Power Administration (WAPA) power line (planned to be 500 Kv). This future power line would occupy the middle 25 feet of this easement. Construction of the WAPA power line is expected to be complete prior , to occupation of the project. Construction of the WAPA line may also result in the removal of the 230 kV USA Power line. Natural Gas Wells The Delta area contains abundant natural gas resources. These resources have been ' extensively developed and are present north of the project site in Rio Vista, to the south on Dutch Slough and to the west on Sherman Island. Some producing wells are also present within the , Bethel Island/Hotchkiss Tract area, The presence of active gas wells in the area presents the remote potential for an explosion or fire. The project site does not contain any existing active gas wells. However, the project site includes five potential drill sites in the form of easements which would allow for future gas exploration under the project site. The potential drill sites are located around the perimeter of the project site. None of these sites has been active (see Section 3.1 for additional discussion of the drill sites). Mosquitos According to the Contra Costa Mosquito Abatement District, nearby areas such as Bethel Island, Jersey Island and Holland Island have historically had high mosquito populations. Mosquito populations primarily became an issue in the springtime after winter rains. The high water table in the project area and vicinity also contributes to mosquito breeding. , Mosquitos present a health hazard because they can transmit diseases such as Western Equine Encephalitis and St. Louis Encephalitis. The transmission of these diseases and other in ' California is rare and the potential risks are managed by local Districts that implement population control strategies. Industrial Emissions The project site is located downwind of several industrial operations which handle hazardous materials or emit certain compounds which may be hazardous to human health in the event of an accident or emergency. 1 3-218 1 r Most of these industrial uses are located west of the project site in Antioch. They include: the DuPont chemical plant; Gaylord Paper Mill; the PG&E natural gas plant; Imperial West; and Kerley agricultural products (Coleman, 1992). As required by Proposition 65, businesses that emit certain compounds must notify the public. Some companies such as DuPont send out notices to area residents on a quarterly basis. Others print notices in the local newspapers or statements in their billings.(Coleman, 1992). IMPACTS rHazardous Materials The project presents the potential to expose new residents to pesticides. However, this risk is extremely low according to the Preliminary Environmental Assessment prepared for the project site. There is no evidence of soil groundwater contamination on the project site. However, due to the past and present agricultural use of the project site and that above ground fuel storage tanks and farm equipment is currently stored on the site, there exists the potential for low levels of residual pesticides and fuel contamination in the soil around these areas. According to the Preliminary Environmental Assessment, the Contra Costa County Department of Agriculture has stated that the site appears to be clear of any significant concentration of pesticides. The Preliminary Assessment concludes that the project site poses no threat to public health and safety and that there is no need for additional testing. Residents of the proposed project could be exposed to agricultural chemicals applied aerially on nearby agricultural lands. Chemicals applied aerially on nearby properties could drift onto the project site and cause adverse health effects and nuisance odors for project residents. tThe level of exposure for project residents would vary greatly depending on the amount of chemicals used and proximity to the application. iAs stated previously, Contra Costa County requires that a 100 foot buffer be established between any building and the aerial application of restricted chemicals. This buffer would reduce ' the potential for chemical drift onto the project site. In addition, Bethel Island Road along the western boundary of the project site would provide an additional buffer between the project and agricultural uses to the west. The project design would also include the construction of a flood ' control levee around the entire project. This levee would provide some protection against chemical drift onto the project site from nearby agricultural uses. While the project location, design and intensity of agricultural uses on adjacent properties would limit the potential for project residents to be exposed to agricultural chemicals as a result of aerial application and drift, this impact would still be considered potentially significant. This impact would be reduced as the surrounding agricultural land becomes developed with residential uses as currently proposed (See Section 5.2 Cumulative Impacts). 3-219 r . r Electrical Transmission Lines The south west corner of the project site contains several large electrical transmission lines, the two 500 kV PG&E lines and the 230 kV USA Power line. In addition, a 500 kV WAPA line is planned to traverse the south-west portion of the project site. The proposed project would place residences adjacent to the existing power line easements at the south-west corner of the project and along both sides of the easement for planned WAPA power line. The WAPA easement is 200 feet in width. The proposedower lines would occupy the P PY middle 25 feet of the easement. The nearest residential property line would be minimum of 88 feet from the power lines plus additional backyard setbacks. Studies of electromagnetic fields r from new power lines have indicated that the strength of the field drops rapidly with distance from the line. At 100 feet the strength of the magnetic field is reduced substantially at the edge of the easement. For example, a hair dryer or electric shaver can have a magnetic field 100 times more than the electromagnetic field at the edge of the easement. The WAPA easement is 200 feet in width to provide a sufficient buffer to reduce exposure to electromagnetic fields (EIR/EIS for the California Oregon Transmission Line, February 1988. An assessment of the significance of electromagnetic exposure and the associated health risks is too speculative based on existing studies and available data. Under CEQA Section 15145, if, after thorough investigation, a Lead Agency finds that a particular impact is too speculative for evaluation, the agency should note its conclusion and terminate discussion of the impact. The proposed school site is located along the eastern border of the project site south of Cypress Road. This location is sufficiently distant from the power line easements to meet applicable California Department of Education criteria. , Natural Gas Wells The project site contains five potential drilling sites. These sites are vacant areas of land and no drills or wells are present. Gas has never been found in this area and there are no known gas resources in this area. As a result the potential for future gas exploration and development , is speculative. A land use permit from Contra Costa County would be required for drilling to take place within 1,000 feet of an areas designated for residential use. Mosquitos ' The proposed project would involve the construction of lakes, a golf course and other , water related facilities including wetland mitigation sites,drainage facilities. These facilities may provide breeding habitat for mosquitos if not properly maintained. In addition, urban development adjacent to existing agricultural uses can result in problems with urban runoff. All ' these factors may lead to additional breeding habitat for mosquitos. This may result in project residents being exposed to mosquito populations which could transmit encephalitis. However, 3-220 ' this impact is considered minor and controllable through proper mosquito population management practices. In addition to health effects, the project would result in additional demand on the services of the Contra Costa Mosquito Abatement District to monitor and eradicate mosquito populations. This potential impact is discussed in Chapter 3.9 Public Services. Industrial Emissions The project site is located down wind of several industrial plants located in Antioch (approximately 10 miles to the west). These plants manufacture various chemicals, agricultural products and/or utilizes certain hazardous materials which may be harmful to human health if an accident occurred at these plants. An accident involving release of hazardous materials could result in the hazardous material travelling via the prevailing winds toward the project site resulting in exposure of project residents to potentially unhealthful levels of hazardous materials. It is important to note that the project site is located a significant distance from these plants and the concentrations of such hazardous materials would be greatly reduced by the time it would reach the project site. In addition, these plants have emergency response plans to deal with any accidents or release of hazardous materials which may affect human health. This impact would not be considered significant. MITIGATION MEASURES Hazardous Materials The following mitigation measure is proposed to inform project residents of this potential hazards associated with adjacent agricultural uses and operations. 3.11-1 Each residence on the project site should include in its CC&Rs a clause consistent with disclosure currently required by the County stating that the incoming property owner is aware of adjacent agricultural uses and the potential hazards related to this land use. (Responsibility: Contra Costa County) Implementation of this mitigation measure would reduce the project's potential impact to a less than significant level. Mosquitos The following mitigation measures are proposed by the Contra Costa Mosquito Abatement District (CCMAD) to reduce mosquito populations which could result from the land uses and drainage impacts of the proposed project and the potential human health risks associated with mosquitos: 3-221 i 3.11-2 The Contra Costa Mosquito Abatement District (CCMAD) should be consulted , during the final design of any wetland mitigation sites to be created on the project site. (Responsibility: Project Applicant/Contra Costa County/CCMAD) 3.11-3 If reclaimed water is used for recreation areas, CCMAD should be consulted regarding the design and testing of alternative methods and disbursement sources. (Responsibility: Project Applicant) Implementation of these mitigation measures would reduce the project's potential impact to a less than significant level. Mitigation For Other Potential Human Health Issues The electrical transmission lines and drill sites resent on the project site do not resent P P J P significant human health impacts. However, the following mitigation measure is proposed to provide project residents with information regarding various human health issues related to these facilities: 3.11-4 Each residence within the project site should include in the CC&Rs a clause stating that the incoming property owner is aware of the specific human health issues related to living near electrical transmission lines and drill sites. (Responsibility: Project Applicant) 3-222 I� 3.12 CULTURAL RESOURCES The following discussion of cultural resources within the project area summarizes the I� findings of two technical reports prepared by William Self Associates entitled: Cultural Resource Assessment Report, Cypress Lakes Proiect, May 1992, and Archeological Survey and Testing Report, Cypress Lakes Project, August 1992. Both are available for review to qualified archeologists at the offices of the Contra Costa County Community Development Department. The report contains information obtained from surface reconnaissance of the project site and archival research of resources from the California Archeological Inventory Northwest Information Center. In June 1992, subsurface probing was also conducted on the project site. EXISTING SETTING Prior to European contact, the Delta was occupied by the Saclan or Bay Miwok. The Saclan were divided into several smaller independent political tribelets who occupied defined territories and controlled access to natural resources. The Julpun is the tribelet known to have occupied the immediate project area. Villages in the Delta were established on natural sand mounds to elevate living areas above the general flood zones. It is believed that the Hotchkiss Mound Site, a large sandmound with scores of burials, was the center of Julpun territory. Cultural Resources Nearly200 burials have been excavated in the vicinity of the project area, the majority tY P J J Y of which were located in the original compact sand layer below the sandy surface soils. Only two of the sites recorded in the vicinity have exhibited the existence of midden soils,dark,friable soil that accompanies occupational sites. Many of the sites discovered thus far may, therefore, have served only as cemeteries. These burials may represent the early Middle Horizon in Central tCalifornia prehistory, which occurred about 3,500 years ago. However, the midden sites tend to contain artifacts representative of Late Horizon occupation, from about 1,700 years ago to the time of European contact. Additional data from stratified cultural deposits in the Delta are needed to more accurately define the relationship of the burials to the relatively few known midden sites. Contra Costa County General Plan The Contra Costa County General Plan designates the Hotchkiss Tract and.project site as an "extremely sensitive area" with respect to archaeological resources (See Archaeological Sensitivity Map in the Contra Costa County General Plan, page 9-15). The Contra Costa County General Plan sets forth the following policy regarding historic and cultural resources: • Areas which have identifiable and important archaeologic or historic significance shall be preserved for such uses, preferably in public ownership. (Policy 9-28) 3-223 In addition to the policies identified above,the Contra Costa County Board of Supervisors on June 19, 1979 adopted a resolution (No. 79/712) endorsing placement of the Hotchkiss Archaeological District on the National Register of Historic Places. This designation,however; was never pursued with the State Historic Preservation Office and Advisory Council on Historic , Preservation. Archival Research Previous Cultural Resource Surveys Numerous surveys have been conducted in the project area and vicinity. Each of these surveys is discussed in more detail in the Cultural Resource Assessment Report, Cvvress Lakes Proiect. Although many archaeological surveys of the immediate project area have proven negative, surveys immediately east of the proposed Cypress Lakes area have recorded several ' prehistoric and historic sites, yielding artifacts and human bone. The majority of these reports, regarding the nature of cultural resource sites in this area, substantiate that, overall, sites tend to ' be buried and most do not exhibit midden or artifacts on the surface. Excavation and grading for construction, and natural erosion have, in the past, led to the accidental discovery of most of the known sites in the area. KNOWN PREHISTORIC SITES Five prehistoric sites are known to exist within the proposed project site (CA-CCo-20, 26, 134, 139, and 647). Of the five sites, CA-Cco-139, the Simone Mound, is potentially the most significant. This site, excavated both in 1939 and 1962 by U.C. Berkeley archaeologists, is known to have contained burials and extensive midden deposits: Much. of this site is now covered by residences and farm buildings. Site CA-CCo--647 in the northeast portion of the project area has been partially destroyed by sand borrow pit excavation, but its remaining ' integrity, size and components make it potentially significant. An additional site, the Hotchkiss Mound, (CA-CCo-138), adjoins the western boundary of the project site. This site was initially excavated in 1936 and subjected to extensive analysis over the past half decade. More than 190 burials and thousands of artifacts have been recorded, as well as remnant house floors from prehistoric occupation. Much of this site is still intact. Some components of this site may occur within or immediately adjacent to the project boundary. Many additional sites have been located in the lands immediately surrounding the project area. The specific location of known prehistoric sites on the project site and in the vicinity are not identified in this document to protect the integrity of these sites. HISTORIC SITES No known State or County listed historic sites have been identified within the project site or immediate vicinity.. 3-224 Field Reconnaissance Several visits to the project site were conducted in April, May and June of 1992. These reconnaissance visits were undertaken to examine the location of the known prehistoric sites within the project area. Since their initial recording, three of the four known sites have been partially destroyed by grading, dozing, erosion and/or flooding. The fifth site was identified and recorded during preparation of this EIR. It had been partially destroyed prior to its discovery. Site CA-CCo-20 was originally contained within a Piper soil mound that was 10 feet or more in elevation. This mound yielded 5 burials by the time it was recorded in 1956. Oral accounts from a long-time resident indicate that the mound was removed entirely by the late 1950's for use as levee fill and as a result of agricultural field leveling. No evidence of this site appears to exist today. Site CA-CCo-26 was originally located at the 0-foot contour at the southeast corner of the 24-foot mound in the northern portion of the project area. The original site record (from 1958)contains little information. It appears that local residents may have reported.finding burials at the location, but none were visible during field reconnaissance by archeologists from UC Berkeley. Auguring done on recent field reconnaissance consisted of placing about 10 holes (at 10 meter intervals) through the dark sand that characterizes the site area. Although large mammal bone was visible on the surface during a walk-over of the site area, no artifacts, charcoal, shell, or other debris indicative of cultural occupation was found in any of the auger holes. ' Site CA-CCo-134, located between the Hotchkiss and Simone mounds just south of the proposed Cypress Road extension, is also somewhat unknown given that the original site record contains essentially no information. A surface survey of the area did yield sparse artifacts, including two apparent pig teeth and obsidian tool fragment. Auger testing of the site indicated that there is a relatively shallow and light concentration of materials (small pieces of charcoal and two small burned bone fragments) in this location. Based upon the evidence from the surface survey and auger testing, it appears that the site no longer retains sufficient integrity to meet the criteria for importance (CEQA) or National Register eligibility (NHPA). Auger testing along the fence line (property boundary) immediately east of the Hotchkiss Mound site also yielded artifacts between the surface and about 45 cm in depth. Recent backdirt from a rodent burrow along the fence line also produced numerous obsidian flakes and other cultural indicators, as well as apparent non-human mammalian bone fragments. This appears to indicate that a portion of site CA-CCo-138 continues east onto the Cypress Lakes project site. Site CA-CCo-139, the Simone Mound, remains relatively intact although several residences have been built upon it. A reconnaissance of the visible ground surface showed traces of cultural materials including obsidian flakes, shell, charcoal, and small pieces of fire-cracked stone. Access to all portions of the mound was not possible due to lack of permission by landowners. The large Piper Mound.that encompasses Site CA-CCo-139 has been built on, no 3-225 doubt, disturbing near-surface cultural resources. Limited auger testing was performed at the mound apex and yielded shell-laden soils,obsidian detritus and burned bone. Site CA-CCo-139 appears to meet CEQA criteria for an "important archaeological resource". It would also be likely to qualify for eligibility to the National Register. Site CA-CCo-647 was discovered during survey and testing at the northeastern portion of the 24-foot mound in the northeast portion of the project area. The site exists at the south end of a borrow pit where digging no doubt led to its visibility and discovery. The. site exhibits mammal-bone, some of which is burned, obsidian and chert tool fragments, shell, ground stone fragments, and other indicators of cultural activity. It appears to continue beneath a light yellow sand layer extending 70 meters (230 feet) south of the area of surface concentration. Auger tests indicate artifacts at depths of from about 60 cm to 150 cm. Based on the remaining integrity and extent of this site, it appears to meet CEQA criteria for an "important archaeological resource" and would also likely qualify for eligibility to the National Register. Areas of archaeological sensitivity within the project boundaries have been mapped and are included in Appendix H. In order to preserve the integrity of these resources, the precise location of any of the known sites is not shown. IMPACTS On-Site Impacts Because the project site is known historically to contain cultural resources, including the possibility of human burials, the proposed project may result in the disruption of cultural resources as a result of the grading and excavation necessary to construct various components of the project. .Field reconnaissance and auger testing to date has indicated that the project would not affect sites CA-CCo-20 or 26 because these sites appear to have been completely removed for levee fill or by agricultural activities and no longer retain sufficient integrity to meet the criteria of importance (CEQA) or National Register eligibility (36 CFR 60.4). Therefore, the project would not be expected to result in a significant impact. Site CA-CCo-134 is located in the general area south of the proposed extension of Cypress Road into the project site near the existing intersection of Cypress Road and Bethel Island Road. It appears that the site no longer retains sufficient integrity to meet the criteria for importance(CEQA)or National Register eligibility. However,due to the close proximity of sites CA-CCo-138 and CA-CCo-139, the area surrounding site CA-CCo-134 is recommended as an area of archaeological sensitivity within which significant ground disturbance should be avoided. This area is approximately 11 acres (see Appendix H). Proposed uses in this area include the internal levee, a natural gas drilling site, the proposed fire station, and a community park. With exception of the proposed fire station, these uses would not be expected to result in significant 3-226 i ground disturbance. Construction of the fire station may result in soil disturbance for site preparation and foundation work. This could impact buried cultural resources within this area. Site CA-CCo-139 is generally located south of the proposed extension of Cypress Road into the project site. The site appears to meet most CEQA criteria as an important archaeological resource and would likely qualify for eligibility to the National Register (36 CFR 60.4). Therefore, the area surrounding this site is'recommended as an area of archaeological sensitivity within which significant ground disturbance should be avoided (see Appendix H for location). Proposed uses in this area include a community park, extensions of Cypress Road, and two lots (No. 10 and 11) in Neighborhood 1 would be partially or wholly within this area. The extension of Cypress Road and the community park would not be considered significant long-term threats to cultural resources in this area but should be monitored closely during construction. Demolition of existing structures for the proposed park and Cypress Road extension would be considered activities which could affect cultural resources and should be monitored closely. The two proposed lots would not be considered an appropriate use within this area. Field reconnaissance d auger testing have indicated that development on most of the 24-foot mound would not be considered a significant impact. However, the area of the new site ' (CA-CCo-647) on the northeast portion of the 24-foot mound would be considered an area of archaeological sensitivity and should be avoided. This site appears to meet most CEQA criteria as an important archaeological resource and would likely qualify for eligibility to the National Register (36 CFR 60.4). Proposed uses in this area include the internal levee and one drill site. These uses would be considered appropriate for providing long-term avoidance and preservation of this cultural resource site. However, the rear lot lines of two lots (No. 29 and 30) in Neighborhood 7 would be within this area. This use would not be considered appropriate for this area. Off-Site Impacts Several off-site roadway improvements associated with the Cypress Lakes project and future development in the Bethel Island Area may impact site CA-CCo-138, the Hotchkiss Mound. These include: Bethel Island/Cypress Road Intersection Improvements: These improvements are directly related to the proposed Cypress Lakes project. These improvements would require widening of Cypress Road near the intersection of Bethel Island Road and may result in impacts to site CA- CCo-138 which is located south of Cypress Road in this area. Extension of Bethel Island Road South: This improvement is not directly needed for the proposed Cypress Lakes project but would be necessary for further development of the Bethel Island Area. Extension of Bethel Island Road south of Cypress Road could impact site CA-CCo- I 138 which is located west of the Cypress Lakes project in the general vicinity of this road extension. 3-227 To avoid impacting site CA-CCo-138, it may be necessary to realign the proposed intersection of Cypress Road and Bethel Island Road to the north or west. In addition, any future extension of Bethel Island Road south of Cypress Road should be located as far east as possible to avoid impacting site CA-CCo-138. Relationship to the General Plan Site specific field studies and archaeological research have been conducted for the project and an archaeological survey report has been prepared which addresses the extent and significance of cultural resources present on the project site. In addition, a detailed mitigation plan has been developed addressing the preservation, avoidance or removal of cultural resources present on the project site. For the most artthe proposed project would avoid or provide for uses which would be P � P P P J considered appropriate for areas of the site which are considered to be archaeologically sensitive. This would be consistent with the Contra Costa County General Plan, which emphasize the preservation of cultural resources in their present condition. In two locations, uses have been identified (single family lots) which would not be appropriate in areas of archaeological sensitivity. Recommendations are provided under Mitigation Measures below to remove these uses or redraw lot lines to avoid these areas. MITIGATION MEASURES The following mitigation measures are proposed to ensure the long-term avoidance and preservation of cultural resources which may be present on the project site: 3.12-1 Due to the existence of subsurface cultural materials along the western perimeter of the CA-CCo-134 site area and the recommendations relative to site CA-CCo- 139 (below), it is recommended that significant ground disturbance be avoided in an area of approximately 11 acres (700 x 700-feet [213 x 213 meters])(see Appendix H). The proposed uses in this area (internal levee, natural gas drilling j site, fire station, community park) are not expected to result in significant ground disturbance. However, all construction activity in this area should be closely monitored to preserve known resources and to determine the presence of any previously unknown subsurface resources in the CA-CCo-134 area. Should sterile soil (e.g., topsoil) be placed over the site for landscaping purposes, it is recommended that rubber-tired construction vehicles be used throughout the site area and that excavation for landscaping or irrigation be allowed in fill material only. Should it be necessary to excavate through native soils, an archaeologist should be present to monitor soil removal for the presence of cultural materials. (Responsibility: Project Applicant) 3.12-2 Significant ground disturbance should be avoided in the area surrounding site CA- g �' g CCo-139; from the 0-foot (sea level) contour to the mound apex at 6.5 feet above 3-228' sea level (see Appendix H). The proposed uses in this area (Community Park, extension of Cypress Road) are not expected to result in significant ground disturbance. However, all construction activities should be closely monitored to -preserve known resources present in this area. It is understood that two private parcels of land on the mound are not included in the project proposal. These recommendations do not apply to those parcels unless they are incorporated into the project proposal at some future time. Should any subsurface disturbance occur on the mound through the removal of structures or foundations, an archaeological monitor should be present to observe soils for the presence of cultural materials. Should sterile soil (e.g., topsoil) be placed over the site for landscaping purposes, it is recommended that rubber-tired construction vehicles be used throughout the site area and that excavation for landscaping or irrigation be allowed in fill material only. Should it be necessary to excavate through native soils, an archaeologist should be present to monitor soil removal for the presence of cultural materials. (Responsibility: Project Applicant) 3.12-3 Construction at the fire station, which would be within the area of archaeological sensitivity for site CA-CCo-139, should be closely monitored and work stopped immediately if cultural materials are encountered. If it is determined that construction is not feasible, the project applicant shall be required to find-an alternate site outside the archaeologically sensitive area. (Responsibility: Project ' Applicant) 3.12-4 Lot No.10 in Neighborhood 1 should be removed or redrawn in a manner that avoids the archaeologically sensitive area associated with CA-CCo-139. (Responsibility: Project Applicant) 3.12-5 Lot No.11 in Neighborhood 1 should be removed or redrawn in order to avoid the archaeologically sensitive area associated with CA-CCo-139. (Responsibility: Project Applicant) - area including and immediate) surrounding site CA-CCo-647 should be 3.12 6 The g Y g avoided to preclude impacts to this important resource (see Appendix H). Should sterile soil (e.g., topsoil) be placed over the site for landscaping purposes, it is recommended that rubber-tired construction vehicles be used throughout the site area and that excavation for landscaping or irrigation be allowed infill material only. Should it be necessary to excavate through native soils, an archaeologist should be present to monitor soil removal for the presence of cultural materials. (Responsibility: Project Applicant) 3.12-7 The rear lot lines of lots No.29 and 30 in Neighborhood 7 should be redrawn in a manner that avoids the archaeologically sensitive area associated with CA-CCo- 647. (Responsibility: Project Applicant) 3-229 i 3.12-8 In the event that avoidance of the preceding cultural resource sites is not feasible, it will be necessary to develop a data recovery or "excavation plan" pursuant to the requirements of CEQA Appendix K, Part V and subject to the limitations defined in Part VI. (Responsibility: Project Applicant) 3.12-9 An archaeological monitor should be present when grading, excavation, trenching and other soil disrupting activities are carried out in any of the mapped �. archaeologically sensitive areas as defined in Appendix H. These activities/areas include, for example, the Cypress Road extension; levee construction/excavation/ compaction; possibly, demolition of existing homes; fire station construction; and the parking lot for the playing fields. (Responsibility: Project Applicant) 3.12-10 An archaeological monitor should be on-call when grading, excavation, trenching ' and other soil disrupting activities are carried out on the project site. In the event that a prehistoric site, burial, or historic resource is encountered during construction of the project, the project engineer would be obligated to temporarily [. stop or relocate construction activities and notify the archaeological monitor immediately. In the event a significant prehistoric or historic resource is identified, no further construction should be permitted in that location until a t mitigation plan can be formulated and implemented. (Responsibility: Project Applicant) 3.12-11 In the event human remains are discovered during construction, excavations should be halted at that location. Any finds of human remains must be reported to the Contra Costa County Coroner's Office. In the event that the find is determined to be prehistoric, the Native American Heritage Commission must be . notified within 24 hours to alert them of the find and to permit the designation of a Native American representative. Consultation between the archaeological consultants in charge of monitoring, Contra Costa County, and the Native American representative would then determine the course of action to be taken with the burial in question. Ideally, if removal is undertaken, time should be allowed for study of the remains and any associated grave goods prior to their return to the Native American Community for reburial at a location of their ' selection. (Responsibility: Project Applicant) 3.12-12 A report of findings and analyses of all archaeological data recovered during testinglexcavation, monitoring and any mitigation procedures undertaken should be prepared by a qualified archaeologist. (Responsibility: Project Applicant) 3.12-13 Sections 5097.98 and 5097.99 of the Public Resources Code also call for "protection to Native American human burials and skeletal remains from vandalism and inadvertent destruction". To achieve this goal, it is recommended that the construction personnel on the project be instructed as to the potential for discovery of cultural or human remains, and both the need for proper and timely 3-230 reporting of such finds, and the consequences of failure thereof. (Responsibility: Project Applicant) 3.12-14 It is recommended that the Native American Heritage Commission (NAHC) in Sacramento be contacted regarding potential Native American concerns, values, and traditional use areas relative to the proposed project site and vicinity. There is a potential for disturbance of previously undiscovered Native American human remains during construction of the project. It would prove advantageous to have an established agreement with the NAHC and/or local Bay N iwok tribal representatives prior to the discovery of such remains, should any be discovered. A typical agreement would specify when, in the event of a discovery, Native American involvement would occur, and the treatment and ultimate disposition of ancestral remains. (Responsibility: Project Applicant) 3.12-15 The proposed intersection improvements at the project entrance and Bethel Island Road should be realigned to the north as much as possible to avoid impacting site CA-CCo-138. (Responsibility: Project Applicant) 3.12-16 The alignment of any future extension of Bethel Island Road south of Cypress Road should be as far east as feasible to avoid site CA-CCo-138, taking into consideration safety factors. This may result in the need to move the project levee along the project's westerly boundary up to 50 feet to the east. (Responsibility: Project Applicant/Contra Costa County) 3-231 3.13 ENERGY EXISTING SETTING The general climate in the Bethel Island Planning Area consists of moderate temperatures, infrequent rainfall, abundant sunshine, light winds and comfortable humidities. The winter temperatures are uniform over much of the Delta area and become progressively warmer to the east and southeast of Bethel Island. The annual rainfall, which occurs almost exclusively from late October to early May, is 12.8 inches per year. Winds through Bethel Island are influenced by the funneling effects of the higher terrain surrounding the Delta area and the local topography of the island itself. The climate and temperature significantly affect residential energy use. Criteria for determining future air conditioning and heating needs are based on the number of heating degree days and cooling degree days per year in a given area. Bethel Island has approximately 2500 heating degree days and 890 cooling degree days, and is well suited for use of alternative energy ' systems. (BIASP EIR, p.V-283) New development throughout California is required to comply with Title 24 Energy Conservation Standards of the California Administrative Code. Mandatory features include wall and ceiling insulation, infiltration control, properly sized space conditioning and hot water " equipment, set back thermostats,and requirements governing swimming pool heating, shower and faucets. In addition, the Solar Rights Act and the Solar Shade Control Act, both passed by the State legislature in 1978, require tentative subdivision maps to provide for future passive solar opportunities to the maximum extent possible. A large source of energy consumption for residential development is related to automobile use. Residents travelling to and from jobs and local errands expend energy in the form of gasoline. The amount of energy expended depends on how far residents need to travel to their jobs and various services such as groceries, doctors, etc. With respect to the East County Area and the project site, the sparse population and rural character requires that most residents travel farther to jobs and for services than in more urbanized areas. Contra Costa Countv General Plan The Contra Costa County General Plan does not provide specific policies regarding energy conservation. The County General Plan states the following implementation measures related to the use of solar energy in new residential projects: • Prepare guidelines for solar design to be included as a revision to the subdivision ordinance. (Implementation Measure 8-br) • Include provisions for solar access within design review of projects. (Implementation Measure 8-bs) 3-232 IMPACTS r The project would result in increases in short-term energy consumption as a result of construction of structures,roads and the public facilities.necessary to serve the project. However, this use of energy would not be considerably different than other similar construction projects in the County and therefore would not be considered a significant adverse impact. An average dwelling unit could be expected to consume approximately 4,869 kilowatt hours (kwh)/year of electricity. Total energy consumption of the proposed homes would be approximately 6.47 million kilowatt hours/year of electricity. The project proposes to incorporate design features in the project homes so that energy consumption would be reduced. The goal of the project would be to exceed the energy efficiency standards of Title 24 by 10%. r` As indicated in Section 3.2,Table 3.2-4,of this EIR,42% of the project generated vehicle trips would head towards State Route 4 to Antioch and Pittsburgh. The second largest group of vehicle trips would be those heading into Oakley. Because of the project location and relative remoteness from employment centers, a larger number of project residents would commute out of the area to jobs. This situation would tend to increase the amount of energy expended for commuting when compared to other residential development closer to urban/job centers. This characteristic of the project would be unavoidable because of the project sites location. However, as planned development in Bethel Island Area and East County continues,jobs and'services will be developed in areas closer to the project site providing the potential to reduce automobile energy expenditures. MITIGATION MEASURES The following mitigation measure is proposed to ensure that energy conservation measures are incorporated into project home designs: 3.13-1 Building plans for each house should include energy conservation features such as passive solar heating, additional insulation and other features so that Title 24 efficiency standards (1991)will be exceeded by at least 10%. These features shall be reviewed and approved by the County Building Department as part of the building permit review process. (Responsibility: Project Applicant) t r - r -r 3-233 r r 4. ALTERNATIVES Section 15126 (d) of the California Environmental Quality Act (CEQA) requires comparative analyses of a reasonable range of alternatives to a proposed project, or the location of the proposed project, which could feasibly attain the basic objectives of the project. The CEQA Guidelines state that alternatives can be considered "reasonable" even if they would impede to some degree the attainment of the project objectives, or would be more costly. The CEQA Guidelines also state that if an alternative would cause one or more significant effects, in addition to those that would be caused by the project as proposed, the significant effects of the alternative should be identified, but in less detail than the significant effects of the project. The range of alternatives to be analyzed is governed by "rule of reason." The key issue is whether the selection and discussion of alternatives fosters informed decision-making and informed public participation. An EIR need not consider an alternative whose effect cannot be reasonably ascertained and whose implementation is remote and speculative. The following alternatives are discussed in this Chapter of the EIR: • 4.1 No Project Alternative • 4.2 Ranchette Alternative • 4.3 Low Density Alternative • 4.4 Maximum Density Alternative • 4.5 Off-Site Alternative • 4.6 Commercial Alternative The following analysis of alternatives evaluates how each alternative would either avoid, reduce, or in some cases worsen,potential impacts when compared to the proposed project. This comparison between the project and the alternatives allows the public and decision makers to clearly understand comparative merits of the alternatives. This approach to the analysis of alternatives to the project is consistent with the CEQA Guidelines Section 15126(d). 4-1 4.1 NO PROJECT ALTERNATIVE RATIONALE The California Environmental Quality Act (CEQA) Section 15126(d) requires that the specific alternative of "No Project" shall also be evaluated in the environmental document. DESCRIPTION OF THE ALTERNATIVE The No Project Alternative would consist of no development,occurring on the proposed project site. The existing uses on the property would remain in its current setting. COMPARATIVE EVALUATION OF ENVIRONMENTAL IMPACTS Land Use Planning and Public Policy -The overall land use pattern under this alternative would be similar to that described in the Existing Setting subsection of Section 3.1 Land Use, Planning and Public Policy of this EIR. The area would not be converted from agricultural/rural uses to suburban/urban uses. This alternative would not provide the recreational facilities or housing opportunities for the County residents that would be provided by the proposed project. The local community has made it clear through public meetings that it wants additional, reasonable development and related infrastructure and amenities. Transportation/Circulation -This alternative would generate considerably less traffic than the proposed project. The existing uses on the project site generate approximately 100 vehicle trips per day. The proposed project would generate approximately 12,000 vehicle trips per day from the project site. The roadway and circulation improvements needed to accommodate the proposed project would not be necessary. Air Quality - Air quality impacts are directly proportional to the number of sources of emissions (mainly automobiles). This alternative would reduce potential air quality impacts associated with the proposed project as a result of fewer automobiles and persons residing on the project site. This alternative would also avoid the project's potential exceedance. of the BAAQMD's significance threshold for emissions of ozone precursors. This alternative would , also avoid the construction-generated dust emissions associated with the proposed project. Vegetation and Wildlife - This alternative would have less impact on existing vegetation and wildlife which are present on the protect site. This alternative would also avoid impacts to existing wetlands and waters of the United States present on the project site (Note: the proposed project would avoid much of the wetland/waters present on the project site and replace impacted wetlands/waters on-site). However, wetland avoidance and preservation may be more difficult under the present agricultural use of the project site. 4-2 Visual Quality-This alternative would avoid the introduction of residences and other uses which would irreversibly change the existing visual character of the project site. This alternative would also avoid construction of the internal levee system which would obstruct views from existing residences in the area. Noise - This alternative would avoid the increase in traffic noise levels associated with the proposed project. In addition, construction-generated noise would be avoided with this alternative. Hydrology and Drainage - Under this alternative no improvements would be made to the existing drainage system on the project site. Under this alternative, the proposed storm drainage improvements would not be constructed, therefore, the beneficial impacts on RD-799 drainage facilities associated with the proposed project would not occur. This alternative would not provide for the potential to improve water quality in Sand Mound Slough by pumping excess storm water into the slough as would occur under the proposed project. Under this alternative the project site would still be exposed to the existing flood hazards which exist on Hotchkiss Tract. Area residents would not be provided a closer evacuation site which would be provided under the proposed project with construction of the internal levee system to FEMA standards. Geology, Seismicity and Soils - Under this alternative, residents would still be exposed v p to the existing geologic, soils and seismic conditions present in the project area. Public Services - This alternative would substantially reduce the need for additional fire police and school facilities that would be associated with the proposed project. However, this alternative would not provide the recreational opportunities and facilities that would be afforded by the proposed project (i.e. golf course, lake/channels, bicycle/pedestrian trails). New public service facilities would not be needed nor constructed under this alternative. Utilities - This alternative would substantially reduce the need for additional utility infrastructure to serve the project site. However, this alternative would not provide the various utility improvements that would be provided under the proposed project. Human Health - This alternative would reduce potential human health risks associated with placing additional residential uses next to agricultural uses,electrical transmission lines and natural gas extraction areas. However, the human health risks associated with locating residential uses on the project site are not considered significant. Cultural Resources - Continued agricultural use of the project site could adversely affect known and unknown cultural resource sites. The proposed project would avoid areas identified as containing cultural resources and preserve them in their existing condition. Energy-This alternative would substantially reduce the energy consumption which would occur with the proposed project. 1 4-3 This alternative would substantially reduce or avoid many of the adverse impacts of the project. However, as identified in the previous sections of the EIR, most of the impacts of the proposed project can be mitigated to less-than-significant levels implementing the proposed mitigation measures. This alternative would not provide certain benefits which would be provided by the proposed project, such as: increased revenues to the County and other agencies which receive property tax revenues from the project site; payment of certain development fees to various agencies; and the development of additional housing units and recreational amenities. This alternative would be considered the "environmentally superior" alternative because of its potential to substantially reduce or avoid many of the potential impacts which would be associated with the proposed project. While many of the potential impact of the proposed project can be mitigated to insignificant levels,avoidance would be considered environmentally superior. When an EIR identities the "No Project" Alternative as "environmentally superior," another alternative should be identified (See Section 4.3). 1 i 4-4 4.2 RANCHETTE ALTERNATIVE RATIONALE The Ranchette Alternative is being evaluated because it would consist of the existing development potential allowed on the project site based on the current agricultural land zoning and land use designations which allow one dwelling unit per five acres. The Off-Island Density Bonus overlay designation would not apply. Clustering would not be required since this Alternative is being evaluated under the existing agricultural zoning. DESCRIPTION OF THE ALTERNATIVE The Ranchette Alternative would result in development of the project site at a density of one (1) dwelling unit per five (5) acres for a total of 136 dwelling units. The resulting land use would be small ranchettes. No recreational amenities would be required with this alternative because the Off-Island Density Bonus overlay designation would not apply for development at this density. ICOMPARATIVE EVALUATION OF ENVIRONMENTAL IMPACTS Land Use, Planning and Public Policy -The land use pattern under this alternative would be more rural in character as a result of larger parcels. However, this alternative could result in piecemeal development of the area and thus a greater conflict between residential and agricultural uses. This alternative would provide significantly fewer housing units than the proposed project. The provision of additional housing in the Bethel Island Area is a goal of Contra Costa County and has been planned for through the establishment of the Off-Island Bonus Area. By significantly reducing the number of housing units possible on the project site, this alternative could be considered to have a significant adverse affect on reaching the housing goals of Contra Costa County in the East County area. This alternative would not provide the recreational facilities (i.e golf course, lake, bicycle/pedestrian trails) that would be created with the proposed project. Transportation/Circulation - This alternative would substantially reduce the number of vehicle trips generated from the project site by approximately 85 percent when compared to the proposed project (this alternative would result in 1,500 vehicle trips per day, 140 vehicle trips per hour). Very few roadway improvements would be necessary to accommodate the traffic �- generated by this alternative. Air Ouality -This alternative would reduce the air quality impacts by roughly 90% when compared to the proposed project. This alternative would also reduce emissions of ozone precursors and potentially avoid exceeding the BAAQMD's threshold for these emissions. Construction-generated dust emissions would also be substantially reduced with this alternative as a result of less soil disruption.. 4-5 Vegetation and Wildlife - This alternative would reduce certain impacts on plant and animal life by creating larger parcels. which would tend to be preserved in their existing agricultural setting. This alternative would also reduce the conversion of foraging habitat for birds which utilize the project site. Some animals present on the project site would still be displaced by this alternative, however, this alternative would result in more undeveloped area for them to migrate toward. This alternative's impact on wetlands is difficult to quantify. Since the site would be developed in smaller pieces it may be more difficult to regulate and mitigate impacted wetlands. Visual Quality-Under this alternative, the internal levee system would not be constructed and the homes would be on larger lots which would more reflect the existing agricultural/rural character of the area. However, in order to comply with the building standards within the floodplain, the houses would be built on stilts, causing an aesthetic impact. The project site would appear to be more urbanized under this alternative than under the No Project Alternative. Noise - This alternative would decrease noise levels relative to the proposed project as a result of less traffic and no recreational uses. As a result, the need for localized noise barriers along Cypress Road would not be expected with this alternative. Construction noise would also be substantially reduced with this alternative. Hydrology and Drainage - This alternative would result in additional storm drainage runoff entering RD-799 drainage facilities as a result of development of additional impervious surfaces on the pr' Ject site. Development under this alternative would most likely not include Oj significant drainage improvements because each parcel would be developed separately . This could result in a greater impact on local drainage facilities than under the proposed project which includes on-site detention facilities. This alternative would not provide an internal levee system, nor would it be large enough to fund improvements of the existing RD-799 levee system on Hotchkiss Tract. Therefore, additional.,people would be exposed to the flood hazards which currently exist on Hotchkiss Tract. Under this alternative new housing would be constructed on stilts which would create an aesthetic impact. This would be a significant adverse impact associated with this alternative which would not be avoided with the proposed project. Geology. Seismicity and Soils - Under this alternative, residents would still be exposed to the existing geologic, soils and seismic conditions within the project area. However, the same mitigation measures identified in this EIR to mitigate soil and geologic hazards could be implemented to reduce,this impact to a less-than-significant level. Public Services - This alternative would reduce the demands on local public services associated with the proposed project as a result of fewer people living on the project site. However, it is not expected that this alternative would be able to provide the necessary level of financing to improve various public"ic services (i.e. fire, police and schools) which would be needed. This alternative would also not provide the recreational facilities and opportunities associated with the proposed project. 4-6 Utilities - This alternative would reduce the level of demand for new utilities associated with the proposed project. However, it is likely that under this alternative a non-groundwater ' source would not be developed for the area. Development of a non-groundwater source is a significant benefit of this proposed project. Human Health - This alternative would result in placing residential uses next to agricultural uses, natural gas extraction areas and electrical transmission lines. These impacts would be similar to those associated with the proposed project, however, human health risks associated with locating residential uses on the project site are not considered significant. Cultural Resources - This alternative could result in adverse impacts to cultural resources as a result of piecemeal development of the site. Under this alternative it would be more difficult to require preservation and avoidance of cultural resources because of the segmented development that would occur under this alternative. The proposed project would avoid known cultural resource sites. Energy - This alternative would reduce the amount of energy consumed when compared to the proposed project. This alternative would reduce or avoid many of the adverse impacts of thero osed P P project. However, as identified in previous sections of this EIR, the impacts of the proposed �. project can be mitigated to less-than-significant levels through the implementation of the proposed mitigation measures. This alternative would not provide certain benefits which would be provided by the proposed project, such as: increased property tax revenues to the County and other agencies; payment of certain development fees to various agencies; and the development of additional housing units and recreational amenities. In accordance with CEQA Section 21085, a public agency shall not reduce the proposed number of housing units as a mitigation measure or project alternative for a particular significant effect on the environment if there is another feasible specific mitigation measure that would provide a comparable level of mitigation. 4-7 1 1 4.3 LOW DENSITY ALTERNATIVE RATIONALE The Low Density Alternative provides an alternative at the low end of the development potential of the project site under the existing land use designation taking advantage of the Off- Island Bonus program. DESCRIPTION OF THE ALTERNATIVE This alternative would involve PP development of approximately 510 dwelling units on the P project site at a density of 1 unit per net acre. The unit count was derived by using the following equation: 681 acres X 75% (25% for road and infrastructure) X 1 dwelling unit = 510. This alternative would include recreational amenities similar to those of the proposed project in conformance with the Off-Island Density program. COMPARATIVE EVALUATION OF ENVIRONMENTAL IMPACTS C S Land Use, Planning and Public Policy - This alternative would have similar land use �. characteristics as the proposed project. However, the intensity of uses on the site would be reduced to some degree. This alternative would result in fewer housing units being developed and therefore would not provide the level of housing opportunities for County and Bay Area residents as the proposed project. A reduction in the number of housing units would increase the amount of open space/park land that could be provided on the site. Transportation/Circulation - The total traffic generated from this alternative would be about 4,800 vehicle trips per day, which is about 40 percent of the trip generation under the proposed project. The PM peak hour trips would amount to about 500 vehicle trips per hour. The traffic impacts of this alternative would be comparatively low, and few roadway improvements would be required. The road widening at the project entrance would be required, but signalization would not. This level of development should be sufficient to fund the necessary roadway improvements. Air Ouality - This alternative would reduce potential air quality impacts associated with the proposed project by approximately 53% based on the reduction in vehicle trips produced by this alternative. However, this alternative may still result in exceedance of the BAAQMD's threshold for emission of ozone precursors. TDM requirements of the County would apply to this alternative to reduce overall traffic generation. Vegetation and Wildlife - This alternative may result in reducing impacts on plant and animal life. The reduced density would allow more flexibility in site planning and would provide the ability to leave certain areas of the project site in agricultural production or as additional open ' space. 4-8 Visual Quality-This alternative would reduce visual impacts because of the lower density and additional open space that would be provided. Under this alternative, homes may be constructed on stilts (unless the project site is removed from the floodplain) which would cause an aesthetic impact. This would result in a more rural character to the project site but would still appear to be more urbanized than under the No Project or Ranchette Alternatives. If the project site were removed from the flood hazard zone by construction of a perimeter levee, this I alternative would result in similar visual impacts as those discussed for the proposed project. Noise- This alternative would have similar noise impacts as the proposed project. While this alternative would generate less traffic and therefore reduce noise levels somewhat, this benefit would not be considered significant. Some noise mitigation measures may be required for this alternative. Hydrology and Drainage - This alternative would have similar drainage impacts as the proposed project. It is assumed that this level of development would be sufficient to support construction of on-site drainage facilities to mitigate potential increases in storm water runoff and impacts to RD-799 drainage facilities. This alternative may result in construction of the internal levee system. However, it is unlikely that 510 units would be sufficient to fund construction of a levee system to remove the site from the 100-year flood plain. Therefore, this alternative would expose additional residences to the existing flood hazards present on Hotchkiss Tract unless homes were constructed on stilts. This alternative would not provide a close evacuation site for area residents in the highly unlikely event of a RD-799 levee overtopping or failure which would be provided with the proposed project. Geology, Seismicity and Soils - Under this alternative, residents would still be exposed i t _ to the existing geologic, soils and seismic conditions which exist within the project area. However, the same mitigation measures proposed for the project to mitigate soil and geologic impacts could be implemented under this alternative. Public Services -This alternative would result in reduced demand on public services from �. that associated with the proposed project because of the reduction in number of units and project population. This alternative would provide a reduced level of financing for improvements to ' various public services, but this level of financing would be commensurate with the level of development under this alternative. Utilities - This alternative would result in reduced demands on utilities from that associated with the proposed project because of the reduction in number of units and project population. Limited utility improvements would be necessary under this alternative and would be expected to be financed by this level of development. A non-groundwater source may not be financially feasible with this alternative. The development of a non-groundwater source is a significant benefit of the proposed project. 4-9 Human Health - This alternative would result in placing residential uses next to ' agricultural uses, natural gas extraction areas and electrical transmission lines. These impacts would be similar to those associated with the proposed project, however, human health risks associated with locating residential uses on the project site are not considered significant. Cultural Resources-This alternative would be similar to the proposed project with respect to the.protection of known cultural resources on the project site. Mitigation measures identified. for the proposed project could be applied under this alternative. Enemy - This alternative would reduce the amount of energy consumed when compared to the proposed protect. This alternative would reduce to some extent the adverse impacts of the proposed project. However, as identified in the previous sections, mitigation measures are proposed to reduce most of the project's impacts to less-than-significant levels. This alternative would not provide certain benefits that would be associated with the proposed project, such as: increased property tax revenues to the County and other agencies which collect property taxes from the project site; additional development fees which would be assessed on the project; and additional housing units. In accordance with CEQA Section 21805, a public agency shall not reduce the proposed �. number of housing units as a mitigation measure or project alternative for a particular significant effect on the environment if there is another feasible specific mitigation measure that would provide a comparable level of mitigation. The Low Density Alternative would be considered the next most "environmentally superior" alternative because of its potential to reduce certain impacts on traffic, air quality, noise and vegetation and wildlife when compared to the proposed project. Air quality could still be a significant impact. The selection of an environmentally superior alternative is not required by CEQA, but is provided for consideration by the Contra Costa County Board of Supervisors. 4-10 4.4 MAXIMUM DENSITY ALTERNATIVE RATIONALE ' This alternative would represent the maximum level of development possible on the project site under the current land use designation and the Off-Island Bonus program. DESCRIPTION OF THE ALTERNATIVE Under this alternative a density of 2.9 dwelling units per net acre would be allowed. This would allow a total of approximately 1,530 dwelling units based on the following calculation: 681 acre project site X 75% (25% for roads & infrastructure) X 2.9 dwelling units = 1,530. The project would include recreational amenities as required by the Off-Island Bonus program such as a golf course, lake, marina or other significant recreational amenity. This alternative would also include construction of an interior levee to FEMA standards as required by the County General Plan. COMPARATIVE EVALUATION OF ENVIRONMENTAL IMPACTS Land Use Planning and Public Policy - This alternative would result in similar land use patterns as the proposed project. This alternative would provide additional housing opportunities for County and Bay Area residents. This alternative would result in a.higher overall project density than the proposed project which may result in less area designated for recreational and open space uses. However, for a project to receive the density bonus substantial recreational ' amenities would have to be provided. Transnortation/Circulation - This alternative would generate approximately 20 percent higher traffic volumes than the proposed project. However, an analysis of this alternative indicates that further road widening and improvements would not be required to accommodate this alternative. Air Quality - The air quality impacts of this alternative would be approximately 13% higher than those associated with the proposed project as a result of the increase in vehicle trips generated by the additional units. This alternative would result in a greater exceedance of the -BAAQMD's threshold for emission of ozone precursors than would be associated with the proposed project. County TDM requirements would apply to this alternative to reduce overall trip generation. Vegetation and Wildlife - This alternative would have-similar impacts on vegetation and wildlife when compared to the proposed project. The high overall density of this alternative may result in reduced area dedicated for recreational and open space uses which would increase impacts to vegetation and wildlife when compared to the proposed project. However, mitigation measures similar to those for the proposed project could be imposed to reduce this impact to an acceptable level. 4-11 1 Visual Ouality-This alternative would have similar visual impacts when compared to the proposed project. Noise - Noise impacts associated with this alternative would be similar to proposed , project. While there would be a slight increase in project traffic, this increase would not be expected to result in a perceivable increase in noise levels. Hydrology and Drainage - This alternative would have similar drainage impacts as the proposed project. In addition, this alternative would be sufficient to support construction of similar drainage improvements as the proposed project to fully mitigate drainage impacts on RD- 799 facilities: This alternative would also include construction of an internal levee system and therefore would have impacts similar to those associated with the proposed project in this area. Geology, Seismicity and Soils - Under this alternative, residents would still be exposed to the existing geologic, soils and seismic conditions present within the project area. 'However, the same mitigation measures proposed for the project to mitigate soil and geologic impacts could be implemented under this alternative to reduce this impact to a less-than-significant level. Public Services - This alternative would result in slightly higher demands on public services from that associated with the proposed project because of the increase in number of units and project population. However, this alternative would provide an increased level of financing for improvements to various public services to accommodate the increased demand. Utilities - This alternative would result in increased demands on utilities from that ' associated with the proposed project because of the increase in number of units and project population. This alternative would be able to provide the increase in level of improvements to various utilities necessary to accommodate the increase in dwelling units and population. Human Health - This alternative would result in placing residential uses next to agricultural uses, natural gas extraction areas and electrical transmission lines. These impacts would be similar to those associated with the proposed project, however, human health risks associated with locating residential uses on the project site are not considered significant. Cultural Resources-This alternative would be similar to the proposed project with respect to the protection of known cultural resource on the project site. Energy-This alternative would increase the amount of energy consumed when compared to the proposed project. The energy conservation measures incorporated into the proposed project could be incorporated into this alternative to reduce overall energy consumption. This alternative would result in similar impacts as those associated with the proposed project. The mitigation measures proposed for the project would also be applicable to the Maximum Density Alternative. This alternative would not avoid or substantially reduce the adverse impacts associated with the proposed project. 4-12 4.5 OFF-SITE ALTERNATIVE RATIONALE As discussed in the introduction to this Section of this EIR, the California Environmental Quality Act (CEQA) states that an EIR must describe a range of reasonable alternatives to the project, or to the location of the project, which could feasibly obtain the basic objectives of the project and significantly reduce or eliminate the significant environmental impacts of the proposed project. Contra Costa County reviewed all vacant developable parcels near the project site to determine if an alternate site was available. One site was selected for further analysis due to location, size and ability to accommodate the basic objectives of the proposed project. The location of the off-site alternative is depicted in Figure 4-1. This site is not owned or under the control of the project applicant. DESCRIPTION OF THE ALTERNATIVE The location of the off-site alternative is depicted in Figure 4-1. This site is located along the north side of Cypress Road and west of Jersey Island Road adjacent to the Off-Island Bonus Area. The site is approximately the same size as the proposed project site. This alternative would include development of the same number of homes as the proposed project (1,330) along with the same recreational amenities as the proposed project. COMPARATIVE EVALUATION OF ENVIRONMENTAL IMPACTS This alternative is designated M-8 by the County. The M-8 (Mixed Use-Oakley Community Center)designation includes three properties totalling 1,539 acres. The eastern most parcel makes up this alternative site. The purpose of the M-8 designation is to provide for the integrated development of these three properties through a comprehensive planning process which will be completed prior to actual development of any of the three properties. The focal point of development in this area is to be a community center complex including a large community park, for either the incorporated or unincorporated community of Oakley. This designation allows broad flexibility in land uses including open space areas,wetland preservation,commercial/office development and single and multi-family residential development. Because of the broad land uses allowed under this land use designation, the proposed uses-would generally be consistent. The proposed project located at this alternative site would have the same basic impacts as the proposed project in the following areas: Noise, Visual Quality; Plant and Animal; Public Service; Utilities; Human Health; and Energy. 4-13 s c ;r -77PR SH r SH "CR T .. CR:�+ DR... ... rR At sk# - Mo MWO i • c9: OS s S AL `PRh CR ML 'SE"a SH , IL SLr CO PR 1 _ O$ _ .+tQ" j.: SL st v CO =� • H _ ti M8 .M8 me TCP. D S A 'Location • Off-Site Aliernative PS M8 _ .- ... AL ~ . os PS MM OS PS s sta K. AL co AL SM ,i. E DFt CYPRESS LAKES & Figure 4-1: COUNTRY CLUB Off-Site Alternative , PROJECT Source: Contra Costa County General Plan Land Use Map 414 Development of the project at this location would result in similar traffic impacts as the proposed project. All of the road capacity results and recommended mitigation measures west ' of the project site would be the same with this alternative. While many of the road improvements to Bethel Island Road would not be necessary with this alternative, there would be other mitigation measures required on Sellers Avenue that would be similar in magnitude and ' cost. With regard to air quality, this alternative site may result in less construction dust ' nuisance because of the reduced number of adjacent residences. Due to multiple ownership of the property it would be more difficult to construct an 1 integrated development in a timely manner. Moreover, the proposed project does not include some of the amenities intended by the M-8 designation (community center complex, commercial/office uses and multi-family development). ' Because this site is outside the Off-Island Bonus area, it would not achieve theg oals of the County Goal Plan to provide additional housing and recreational amenities in the Bethel Island and Hotchkiss Tract areas. 4-15 4.6 COMMERCIAL ALTERNATIVE , RATIONALE This alternative is the same as the proposed project with the addition of a commercial ' component. This alternative is being evaluated to address the Jobs/Housing imbalance of the proposed project and the East County area. DESCRIPTION OF THE ALTERNATIVE This alternative would include the same level of residential as development the proposed P project (1,330 dwelling units) as well as the same basic recreational amenities (golf course, beach club,lake). However,this alternative would include neighborhood commercial development near the project entrance at Cypress Road and Bethel Island Road. This commercial area would provide neighborhood commercial space for local serving businesses and services such as: a ' grocery store,cleaners,video store,restaurant,professional offices(real estate,insurance,medical etc.) and a bank. COMPARATIVE EVALUATION OF ENVIRONMENTAL IMPACTS Land Use, Planning and Public Policy - This alternative would result in the same overall ' land use pattern as the proposed project with the exception of the addition of commercial uses near the project entrance at Cypress Road. The General Plan designation for the project site does not include commercial uses. An amendment to the General Plan would be required to allow ' commercial development on the project site. Additional commercial development would provide additional jobs, improving the Jobs/Housing balance in East County. This alternative would result in the same housing and development opportunities as the proposed project. ' Transportation/Circulation-The commercial component of this alternative would generate approximately 2,700 vehicle trips per day. However,this would not result in a significant change ' in the impacts and mitigation measures of the proposed project. This alternative would capture many trips internally by reducing the number of trips made off-site for jobs and commercial services. However, this would be partially offset by new trips to the commercial uses by employees, deliveries and customers from other areas. Air Ouality - The local and regional air quality impacts of this alternative would be , approximately 15% greater than the proposed project as a result of the increased number of vehicle trips generated by the commercial component of this alternative. TDM requirements would also apply to this alternative to reduce overall trip generation. Vegetation and Wildlife - This alternative would have similar impacts on vegetation and wildlife as the proposed project. 4-16 Visual Quality - This alternative would have the same visual impacts of the proposed project with the exception of the project entry at Cypress Road where the visual character of the project would be that of a local serving commercial center. This change in visual character would not be considered significant. Noise - This alternative would have similar noise impacts as the proposed project. However, the commercial uses would generate additional traffic noise and noise as a result of truck deliveries and mechanical equipment. Hydrology and Drainage - This alternative would result in the same hydrology and drainage impacts as the proposed project. Geology, Seismicity and Soils - Under this alternative, residents would still be exposed to the existing geologic, soils and seismic conditions present within the project site. Public Services - This alternative would result in slightly higher demands on public services from that associated with the proposed project because of the addition of commercial uses. However, this increased demand would not be considered significant. With regard to school impacts, the commercial uses would provide additional school impact fees, but would not produce additional school enrollments. This aspect of this alternative would be beneficial. Utilities - This alternative would result in a slight increase in demands on utilities from that associated with the proposed project because of the addition of commercial uses. However, this increase would not be considered significant. Human Health - This alternative would result in placing residential uses next to agricultural uses, natural gas extraction areas and electrical transmission lines. These impacts would be similar to those associated with the proposed project, however, human health risks associated with locating residential uses on the project site are not considered significant. Cultural Resources-This alternative would be similar to the proposed project with respect to the protection of known cultural resource on the project site. Energy - This alternative would result in a slight increase in the amount of energy consumed when compared to the proposed project. This alternative would result in similar impacts as those associated with the proposed project. The mitigation measures proposed for the project would be applicable for the Commercial Alternative. This alternative would not avoid any of the adverse impacts associated with the project. This alternative may result in additional air quality impacts. This alternative could reduce the jobs/housing impact of the proposed project by providing additional employment on-site. Provision of additional jobs in the Bethel Island Area would be considered a beneficial impact of the Commercial Alternative. However,the provision of commercial uses on the project site would require an amendment to the County General Plan. 4-17 ' 5. OTHER CEOA SECTIONS 5.1 SIGNIFICANT UNAVOIDABLE ADVERSE IMPACTS RESULTING FROM THE ' PROPOSED PROJECT Chapter 3 of this EIR identifies the environmental impacts of the proposed project. In many cases, the mitigation measures proposed in this EIR can minimize impacts of the project to less-than-significant levels. Section 15126 (b) of the California Environmental Quality Act (CEQA) Guidelines requires that significant impacts of the project which cannot be reduced to ' a less-than-significant level be described. The proposed project would result in the following unavoidable significant impacts: ' Air Quality The project would exceed Bay Area Air Quality Management District significance thresholds for emissions of ozone precursors (NOx and ROG). ' Visual Quality: The would,• tv: Inject �u 1,result in an unavoidable impact on the existing visual character of the project site and the views from adjacent residences along Sandmound Boulevard. Mitigation measures are proposed to reduce this impact (see Section 3.5 Visual Quality), however, the impact would remain significant. ' Jobs/Housing Balance: Because the East County area currently has more housing units than jobs,. the project would result in an unavoidable impact on East County's ' jobs/housing balance which could promote additional community to employment centers in Walnut Creek/Concord and other job centers in the East Bay. The impact of the project would be unavoidable in the short-term until businesses and jobs are attracted to ' the East County area. • Noise: Construction of the project would result in elevated noise levels at local ' residences. Mitigation measures are proposed to reduce this impact. However, construction period noise would still be considered a short-term unavoidable impact on local residents. • Construction Period Dust: The project would result in elevated dust emissions during construction periods as a result of excavation and grading activities. Mitigation measures ' are proposed to reduce this impact. However, construction activities would still generate dust which may result in a nuisance at local residences. This would result in a short-term unavoidable impact on local residents. 5-1 5.2 CUMULATIVE IMPACTS , The California Environmental Quality Act (CEQA) defines cumulative impacts as two or more individual effects which, when considered together, are considerable, or which can ' compound or increase other environmental impacts. Section,15130 of the CEQA Guidelines requires consideration in an EIR of potential environmental impacts that are individually limited but cumulatively significant. These impacts can result from the proposed project alone or ' together with other projects. "The cumulative impact from several projects is the change in the environment which results from the incremental impact of the project-when added to other closely related past, present, and reasonably foreseeable probable future projects." ' In considering cumulative impacts, CEQA allows the use of a list of projects potentially affected by the proposed project. The cumulative impact analysis in this EIR is based both upon , a list of approved and under review projects in the study area and upon projections of areawide significant growth patterns, as required by Section 15130 of the CEQA Guidelines. The following list summarizes past,present and reasonably anticipated future projects, and a summary , of projections contained in the County General Plan for areas adjacent to the proposed project site. Projects within the Bethel Island Area Planning Area The following projects have either been approved but are not constructed yet, or have , applications for approval on file at the Contra Costa County Community Development Department: , • South River: proposed 575 unit project located south of the proposed project site. • North State Development: proposed 14 single family residential/agricultural project r located north of the project site along Sandmound Boulevard. • Lesher Landing: proposed 1,079 unit project located west of the proposed project along ' the north side of Cypress Road. • Willow Park Marina No. 3: approved 62 unit condominium project. located along Sandmound Boulevard. • Conner Property: approved 236 unit residential project located on the north side of ' Gateway Road, east of Bethel Island Road and south of the canal. • Delta Coves Project: approved 550 unit small-lot recreation homes located south of ' Gateway Road and east of Bethel Island Road. • Subdivision 6610: approved 91 unit single family residential project located at the ' southeast end of Sandmound Boulevard. 5-2 t ' Bacon Project: proposed 75 unit single family home project along the inland side of the levee at Taylor Slough. • Anchor Marina:proposed expansion of an existing marina (67 covered berths,marina and boat ramp facilities, dry boat storage, mini-storage, office and convenience store, recreational vehicle park, and picnic/campground area) located one mile northwesterly of ' Bethel Island Road. The following is a summary of the potential development allowed within the Bethel Island Planning Area. • Within the Hotchkiss Tract Off-Island Bonus Area approximately 2,998 units are proposed ' (South River, North State Development, Willow Park Marina, Lesher Landing). In addition to this development, there is the potential for an additional 398 units as allowed under the base density allowed on Hotchkiss Tract of 1 unit/5 acres. The total number ' of units exceeds the number of allowed units on Hotchkiss Tract (3,000) and would require an amendment to the County General Plan for all units to be constructed. ' On-Island development limited to one unit per parcel (approximately 200 units could be developed). ' 100,000 square feet of commercial development and 500 hotel rooms. • Commercial recreation/marina commercial uses. ' • Neighborhood commercial integrated into residential development. ' Proiects or Land Uses Outside the Bethel Island Planning Area ' The following list summarizes currently proposed projects and future development potential of lands surrounding the project site but outside the Bethel Island Planning Area. ' Cypress Corridor: This area is located north of Cypress Road between Marsh Creek and Jersey Island Road, and includes 1,539 acres which have been designated for mixed-use development. The site is intended to function as a community center for Oakley. Land ' uses would include single family and multi-family residential (1,135 to 1,480 acres); commercial (15 to 20 acres); office (30 to 40 acnes); commercial recreation (20 to 30 acres); parks and recreation (100 to 150 acres); and public and semi-public (25 to 35 acres). • Cowell Ranch: A General Plan Amendment application has been filed and a rezoning ' application is on file for approximately 6,000 residential units with business and commercial uses for 5,000 acres southwest of Brentwood. 5-3 1 • Mixed Use Laurel Road (M-9) Area: This area is located on the south side of Laurel ' Road at the ATSF railroad tracks and is planned as a transition from the lower density, single-family residential use to traditional commercial uses. • Pittsburg-Antioch Area: The County General Plan anticipates approximately 12,000 new housing units in this area. The rest of the East County includes unincorporated Oakley, Bethel Island and Discovery Bay. ' • Brentwood: The City of Brentwood is in the process of updating its General Plan. Presently, there are approximately 12,000 units proposed or approved in this area. ' • An application for incorporation of the Town of Oakley was filed but has since been withdrawn. The project site and Hotchkiss Tract are not included in the application. , • Byron 78: A general plan amendment project located at the corner of Bixler Road and SR4 in the Discovery Bay area. The project covers approximately 78 acres of which 21 ' acres would be developed with commercial uses, 13 acres with office uses; and 44 acres with light industrial uses. Cumulative Impacts ' The following discussions summarize potential cumulative impacts which may occur when , the proposed project is combined with the approved,pending and reasonably anticipated projects discussed above. The cumulative impact analysis contained in this EIR is based on the specific analysis conducted for the Cypress Lakes project; conducted and contained in the County General , Plan, January, 1991, and the Final EIR on the County General Plan, 1990. These documents are incorporated by reference pursuant to CEQA Guidelines 15150. The referenced documents are , available for public review at the Contra Costa County Community Development Department, 701 Laurel Street, Martinez, California. The proposed project's impacts, and appropriate mitigation measures, in any one of these areas are discussed in Chapter 3 of this EIR. ' Land Use: The proposed project in connection with other planned future development in the area will result in an irreversible change in the existing land uses of East County and the Bethel Island Area. While this change has been planned for through adoption of the County General Plan, ' which designates an Off-Island Density Bonus Overlay District for Hotchkiss Tract, and established an Urban Limit Line through the passage of Measure C, which identifies those areas , of the County which can be developed with urban uses. The change in land uses would be an irreversible change associated with urban development. General Plan amendments may be required for future development in the Bethel Island Area if proposed development exceeds the ' residential cap. The proposed project does not require an amendment to the County General Plan. Traffic/Circulation: The cumulative impacts of development on the Bethel Island area and East ' County are addressed in Chapter 3.2 of this EIR. The cumulative traffic volumes in the planning 5-4 r ' area are depicted on Figure 3.2-11. The proposed project would contribute to cumulative traffic impacts. Mitigation measures for cumulative traffic impacts area discussed in Chapter 3.2 of this EIR and include construction of the Delta Expressway. The project would contribute to the ' construction of this improvement through the payment of the County's Subregional Road Fees. If the Delta Expressway does not go forward, the following mitigation measures would apply to the project to mitigate cumulative traffic impacts: rImprove the Neroly Road/SR 4 intersection (mitigation measure 3.2-11). The project should pay 10% of the cost of this improvement. ' Improve the intersection of Cypress Road/SR 4 (mitigation measure 3.2-12). The project should pay 25% of the cost of this improvement. ' Other regional improvements needed to accommodate cumulative growth include the improvement of SR 4 from Bailey Road to SR 160. Air Quality: The project in combination with other projects proposed in the BI Planning Area r � r � r r � would add incrementally to emissions in the Bay Area Basin. However, future projects would be subject to the County's TDM requirements which would help reduce the total number of automobile trips in the County. Cumulative development would be expected to result in a cumulative impact on region emissions (NOx and ROG in particular). Vegetation and Wildlife: The proposed project in connection with other cumulative development ' in the area will result in the loss of vegetation and wildlife habitat. However, the County has a "No Net Loss of Quality or Quantity of Wetlands" policy and is currently preparing a wetlands ordinance to protect wetland areas throughout the County. In addition, the County requires that ' projects provide adequate mitigation such as replacement habitat or avoidance of sensitive areas. County policy further requires that impacted wetland be replaced in a ratio of 3:1 wherever possible. In addition to these policies the County has, through the passage of Measure C, ' established an Urban Limit Line within the County which delineates those area where urban development may be contemplated, The intent of the Urban Limit Line and Measure C is to limit urban development within the County to 35% of the land area. The retraining area (65%) is to be left in its current rural/agricultural/wetland state. Visual Quality: The proposed project in connection other proposed projects in the BI Planning ' Area and development of the Oakley Planning Area,would contribute significantly to the change in visual character of the East County region from primarily agricultural to a mix of suburban residential and agricultural uses. Pastoral visual qualities of the area would be diminished, and suburban qualities would be enhanced. This cumulative impact would be an unavoidable impact of urban development. ' Noise: The proposed project in connection with other planned development in the area may result in cumulative noise impacts. Cumulative noise impacts will be addressed through environmental review of future projects and requiring conformity with County noise standards. r 5-5 r r 1 Standard noise mitigation measures may include increased setbacks along major roadways; ' architectural treatments of homes to reduce interior noise levels; and local noise barriers. The proposed project will contribute to adverse cumulative noise levels along Cypress Road. Mitigation for this impact includes local noise barriers (see Section 3.6,mitigation measure 3.6-1) ' which will reduce cumulative noise levels to normally acceptable levels. Hydrology and Drainage: The project in connection with other planned development in the area ' may result in cumulative changes to regional hydrology and drainage patterns. This cumulative impact will be addressed through environmental review of future projects and conformance with County policy and Gwwth Management requirements regarding the provision of adequate , drainage facilities to be constructed as part of any future development project. Hydrological and drainage impacts can generally be mitigated through proper engineering techniques and the use of detention basins or other drainage facilities. The proposed project includes the use of ' detention facilities in the form of the proposed lake and channels to mitigate the project's drainage impacts to a less-than-significant level. 'n connection with other planned future development in Geology, Soils, Seismicity: The project i co p p the Bethel Island Area would result in exposure of additional persons to potential hazards from liquefaction and seismic shaking. This potential cumulative impact will be addressed through ' requirements that detailed geotechnical plans and measures to satisfactorily address liquefaction problems be developed prior to project approval and through the requirement that all structures ' be constructed to withstand seismic shaking. Public Services: The project in connection with other planned future development in the area , will result in additional demands on public services, such as police, fire and schools. This cumulative impact is addressed by compliance with County Growth Management requirements and other County policies which require future development to pay its fair share toward impacts ' on community services. Therefore,cumulative impacts on Public Services will not be significant. Impacts on public services are of particular concern due to recent County and state budget cuts. In the future, developments will be required to pay for more of the cost of providing these services than has occurred historically. Special tax districts or privately financed services may ' be required as conditions of approval on new development. Utilities: The project in connection with other planned future development may result in , cumulative impacts on utilities (water, sewage disposal,electricity and gas,telephone service and solid waste). These impacts are discussed below: ' • Cumulative impacts on water may be significant. However, the Oakley Water District which serve the project site has prepared a Water Management Master Plan which ' addresses the District's ability to serve development within its Sphere of Influence. The impact of cumulative development on water resources is unclear at this time due to the continuing drought situation and the potential for additional water resources to be diverted , to fish and wildlife needs. It is likely that water resources will become the primary limiting factor of future development. New facilities are being constructed to serve r 5-6 i projected growth but not to induce growth. As a requirement of Measure C and the Growth Management policies, future development is required to demonstrate adequate available capacity prior to project approval. ' Cumulative impacts on sewage disposal may be significant. However, at this time the Ironhouse Sanitary District has adequate capacity to serve the project and some limited ' future development. Future development.fees would provide a funding source for future expansion of the District's capacity. New facilities are being constructed to serve projected growth but not to induce growth. As a requirement of Measure C and the ' Growth Management policies, future development is required to demonstrate adequate available capacity prior to project approval. ' Cumulative impacts on electrical, gas and telephone utilities are not expected to be significant. • Because the County has recently approved new solid waste sites, cumulative impacts on solid waste disposal are not expected to be significant. Human Health: The Delta area historically has experienced mosquito problems. Cumulative development in this area may expose additional persons to potential health hazards transmitted by mosquitos. This potential impact is addressed by CCMAD which is responsible for mosquito abatement and management. Future projects in the Delta area should be required to conform with CCMAD requirements regarding drainage and lake designs. Implementation of standard maintenance practices and proper design of drainage facilities would mitigate this potential impact to a less-than-significant level. ' Cultural Resources: The project in connection with other planned future development in the area may result in cumulative impacts on buried cultural resources. This potential impact will be addressed through the environmental review process and requirements for cultural resource studies in areas known to contain cultural resources.such as the Delta area. The environmental review process would be used to identify areas most sensitive to development and provide for the avoidance or limitation of development in these areas. With regard to the proposed project, ' areas of the project site which may contain significant cultural resources are avoided. a 5-7 5.3 SIGNIFICANT IRREVERSIBLE CHANGES , The California Environmental Quality Act (CEQA) Section 15126 (f) requires (1) an analysis of the justification of uses of non-renewable resources during the initial and continued , phases of a project which may be irreversible since large commitment of such resources makes removal or nonuse thereafter unlikely; and (2) an analysis which describes irreversible damage that could result from environmental accidents with a project. ' The proposed project would result in the following irreversible changes: • The commitment of energy and raw materials for development would deplete certain non- ' renewable resources. The project will also lead to irreversible foreclosure of a portion of the agricultural uses within the Bethel Island Area. , • The project would result in an irreversible impact on the existing hydrology of the Hotchkiss Tract floodplain by removing approximately 685 acres from the flood hazard ' zone and constructing a internal levee system around the project. The internal levee system would result in altering the direction of flood waters in the highly unlikely event ' of a RD-799 levee failure and would result in-the remaining portions of RD-799 being flooded faster due to the reduced flood plain area. While the project site would provide a closer area of safety for area residents in the event of a RD-799 levee failure, this ' impact would be irreversible with the proposed project. 5-8 ' 5.4 GROWTH INDUCING IMPACTS According to the California Environmental Quality Act (CEQA), a project is considered ' to be growth inducing if the project could directly or indirectly foster economic growth or population growth. Extensions of urban services or transportation facilities into previously unserved or under served areas, and other projects which remove obstacles to growth or generate substantial economic or employment activity would be considered growth inducing. The proposed project could result in growth inducing impacts as a result of the required ' annexations to the Oakley Water District, Contra Costa Water District and Ironhouse Sanitary District. The proposed project would extend water service from State Route 4 along Cypress Road to the project site as well as construct the necessary sewer facilities to serve the project. ' This new accessibility to water and sewer facilities would encourage continued growth in the East County area. However, services would be extended through the Cypress Corridor, an area that is identified for planned urban development. The project site and other properties west of Sand Mound Slough are within the Urban Limit Line. The project site and the remainder of the Hotchkiss Tract are within a Specific Plan Area. Consequently, this growth would not be expected to exceed that which is envisioned in the County General Plan for the Bethel Island Area. To ensure that growth does not exceed planned levels, water and sewer infrastructure should not contain capacity in excess of that necessary to accommodate planned development levels in the Bethel Island Area. The proposed protect could also result in growth inducing impacts as a result of the required roadway improvements. Presently, the roadway system in and around the project area is in an unimproved state. Improvements to the roadway system may encourage additional development in the area. ' With an existing population of about 3,000 residents and a proposed project population of about 3,229 residents and projected population of 11,000 residents, the Bethel Island Area would experience,significant population growth. This growth would place additional pressure for conversion of agriculturally-designated lands to low-density residential uses. ' The Bethel Island Area abuts Jersey Island to the west and Holland Tract to the east and southeast. Both of these areas are in open space or agricultural use, and have severe infrastructural constraints. However, if development as proposed and projected becomes successful, it could potentially attract developers to consider developing these adjacent Delta tracts some time in the future. In terms of growth-inducing impacts on surrounding areas,rural east Contra Costa County, in Antioch,Brentwood, and the Oakley area is projected to have the County's highest rate of population growth during the next two decades (ABAG 1991). Much of this projected growth would take place in incorporated cities and within their spheres of influence and may occur regardless of future development patterns or rates of growth in the project area. Improvements to the road system, utilities and public services required by growth in the project and Bethel 5-9 1 1 Island area would not play a significant role in determining the rate of growth in these adjacent ' areas. Major infrastructure improvements required to serve future residents would be assisted by financing.proposed in the Specific Plan, however, and may act to stimulate residential and commercial development in the immediate project area. 1 1 . 1 1 1 1 1 i . i 1 i 1 1 1 5-10 1 1 5.5 RELATIONSHIP BETWEEN LOCAL SHORT-TERM USE AND THE MAINTENANCE AND ENHANCEMENT OF LONG-TERM PRODUCTIVITY ' The relationship between local short term uses of man's environment and the maintenance and enhancement of long term productivity is often one of tradeoffs, or the balancing of social, ' economic, and environmental impacts over time. In some cases, a relatively short term benefit may have adverse cumulative effects, with the possibility that future generations and the future economy may be burdened with unwarranted social and environmental costs. The opposite ' situation, in which long term benefits occur at the expense of short term impacts, is also possible. Decisions that influence the balancing of such impacts for this project are the responsibility of the Contra Costa County Board of Supervisors as part of their policy making and regulatory functions. Adverse short-term impacts of the proposed project would result from construction. Examples of these impacts would include visual disruption, nuisance dust emissions, and energy consumption. Construction impacts would not be considered significant due to the relatively short duration. Examples of long-term adverse effects would include: reduction in agricultural I uses within the Planning Area,increased population and its resulting impacts on traffic congestion on local roadways,noise and air quality. The project would also permanently change the existing patterns of vegetation and wildlife habitat on the project site. ' Beneficial long-term effects would include increased housing and recreational opportunities for County residents. 1 ' S-11 1 ' 6. REFERENCES/PERSONS AND ORGANIZATIONS CONSULTED 1. Kaldveer Associates, Preliminary Environmental Assessment, February 27, 1989. 2. Bethel Island Fire Protection District, Chief Jack Whitener, personal communication May ' 5, 1992. 3. Brentwood Disposal Company, personal communication with office staff May 5, 1992. 4. Bohley/Maley Associates, Peter Bohley, personal communication, June 1992. 5. Contra Costa County Auditor's Office,personal communication with office staff May 12, 1992. 6. Contra Costa County Community Development Department, Ray Valone, personal communications May 5 and 7, 1992. 7. Contra Costa County Flood Control and Water Conservation District, Sam Choi, Staff Engineer, personal communication May 7, 1992. 8. Contra Costa County Sheriffs Department,Delta Station House, Sgt.Phil White,personal communication May 7, 1992; Reed McDonald, personal communication August 7, 1992. 9. Contra Costa County Sheriff's Department, Martinez Headquarters, Lt. Scott Parsons, personal communication May 12, 1992. 10. Contra Costa Water District, Dennis Pisila, Utility Planner, personal communication May 6, 1992. 11. DuPont Chemical Plant, Ian Dunn, Plant Manager, telephone communication, May 5, 1992 ' 12. DuPont Chemical Plant, Coleman, Brian, Environmental Manager, telephone communication, May 7, 1992. 13. Ironhouse Sanitary District,James Elder,District Engineer,personal communication May 5, 1992 and June 1992. 14. Kleinfelder Inc., Ron Heinzen, personal communication, June 1992. ' 15. Land Planning Consultants, Inc., consultant to Liberty Union High School District, Kimberly Wood, personal communication May 5, 1992. 1 6-1 16. Lindorff& Associates, consultant to Ironhouse Sanitary District, Mary Lindorff, personal , communication May 5, 1992. 17. Oakley Disposal Company, Gloria Gonzales, personal communication May 6, 1992. ' 18. Oakley Fire Protection District, Assistant_ Chief Manual Tovar, personal communication May 5, 1992. ' 19. Oakley Union Elementary School District, Louis Bennett, Facilities Director, personal communication May 6, 1992. 20. Oakley Water District, Bonnie McLain, personal communication May 6, 1992. 21. U.S. Geological Survey, Evaluation of Selected Data to Assess the Causes of Subsidence in the Sacramento-San Joaquin Delta, California, 1991. r i 6-2 ' 7. LIST OF PREPARERS ' This report was prepared by Public Affairs Management of San Francisco, California with technical assistance from Abrams Associates (traffic),Don Ballanti Consulting Meteorologist(air quality), William Self Associates (cultural resources) and Charles Salter Associates (noise). ! Public Affairs Management and the technical consultants involved in the analysis presented in this report haves no financial interest in the approval or disapproval of the Cypress Lakes & Country Club project. The persons participating in the preparation of this document are: NAME/ORGANIZATION RESPONSIBILITY/SPECIALTY Mr. Dennis Barry Project Coordinator Contra Costa County Community Development Dept. Mr. Art Beresford Project Manager Contra Costa County Community Development Department ' Kay A. Wilson Principal in Charge Public Affairs Management Scott L. Steinwert Project Manager ! Public Affairs Management Jo Julin Land Use/Policy Analysis Environmental Planner ! Charles Abrams Traffic Analysis Abrams Associates ' Alan Rosen Noise Analysis Charles M. Salter Associates ' William Self Cultural Resource Analysis William Self Associates Don Ballanti Air Quality Analysis Don Ballanti Consulting Meteorologist ! 7-1 Additional Technical analysis was provided by the following: , NAME/ORGANIZATION RESPONSIBELITY/SPECIALTY Peter Bohley ' Bohley/Maley Associates Drainage, Levees and Water Quality 1 7-2 ' 8. APPENDICES Appendix A - Initial Study Appendix B - Air Quality Methodology and Assumptions rAppendix C - List of Plant Species Observed During Field Surveys Appendix D - Wetland/Landscaping Information Appendix E - Geotechnical/Hydrology Information Appendix F - Will Serve Letter from Oakley Water District Appendix G - Will Serve Letter from Ironhouse Sanitary District Appendix H - Cultural Resource Appendix 1 8-1 Appendix A ' Initial Study 1 1 t t t t t t t t Community Contra Harvey E. Bragdon Director of Community Development Development Costa Department' County County Administration Building 651 Pine Street 4th Floor, North Wing _ Martinez, California 945530095 i Phone: (510) 646-2031 February 6, 1992 rA c8uei NOTICE OF PREPARATION ' ENVIRONMENTAL IMPACT REPORT FOR CYPRESS LAKES AND COUNTRY CLUB. A.J. Solomon/Chartered Land & Cattle Co. (Applicant) Three Sisters Trust (Owner) County File #2918-RZ, Final Development Plan 3032-90, Subdivision 7562: A request to rezone 682 t acres from Agricultural Districts (A-2) and (A-3) to Planned Unit District (P-1); and for final residential development plan and vesting tentative map approval for 1,301 single- family dwelling unit/lots, golf course, lakes and associated recreational facilities and commerical areas. The subject side fronts on the east side of Bethel Island Road between Cypress Road and Sandmound Boulevard approximately 2.7 miles east of the town of Oakley, South of Bethel Island in eastern Contra Costa County. Site also fronts on the south side of Sandmound Boulevard east of Bethel Island Road, and on the west side of Sandmound Boulevard north of the .proposed Cypress Road extension. (Parcel# 032-210-029/032-220-005,7,8,12,26) (CT 3010.00) (ZA: G-77, 28/ H-27,28) As the owner or occupant of abutting or nearby property, or as an otherwise interested person or organization, you are invited to submit any comments you may have on this project, and raise any significant environmental issues of which you are aware so that they can be considered in the environmental review process. - This letter plus enclosures will constitute a Notice of Preparation. Please circulate this information to the appropriate persons and agencies as soon as possible. I would encourage those interested to contact me directly by phone or letter to convey any concerns they may have about the environmental ' review for the project. If you require further information regarding this Notice of Preparation, or if you have any comments regarding the environmental review of this Notice of Preparation, please contact me & Byron Turner of Community Development Department at 510/646-2031 no later than March 13, 1992, 5:00 p.m. Sincerely yours, Art Beresford ' Senior Planner AB/at 1 ' S. SUMMARY The project' s basic components include a vesting tentative subdivision map, request for rezoning from A-2 (Agricultural) to f P-1 (Planned. Unit Development) , preliminary commercial development plan and final residential development plan for 1, 301 single-family residential dwelling units with recreational amenities. Specific project components include: a golf course; a swim and tennis club; lakes; commercial and marine related uses, and internal levee system; a day care center; a boater' s club and storage area, a school site (optional) ; parks, open space and wetland areas all on approximately 683 areas. The project also includes the establishment of public financing districts to help pay for required infrastructure improvements; transportation improvements; boundary reorganization/annexation to the necessary service districts, such as water, sanitary and fire districts and related public improvements; and improvements which may be required by Reclamation District 799. The project also includes any other land use and development approvals and permits necessary to carry out the project, including but not limited -to, permits from state and federal agencies (e.g. Department of Fish and Game, U.S. Army Corps of Engineers, FEMA . etc. ) ; a final commercial development plan; a development agreement (the existing one as it may be amended to incorporate any new entitlement or a new one to reflect such new entitlement) ; and any other measures or programs necessary to implement the Bethel Island Area Specific Plan as it relates to this project site. The findings of this Initial Study indicate that an EIR is necessary for the proposed project. Information contained in prior EIRs on the Specific Plan and County General Plan may be considered in the preparation of the EIR on the proposed project. However, the EIR for the proposed project will be prepared as a separate EIR and will not rely on the impact findings of the Specific Plan or County General Plan EIRs. The project application may be amended during the EIR process in response to environemntal issues and concerns raised. Amendments made prior to completion of the draft EIR will be discussed thoroughly in the EIR. The project will be proceeded under both 1) the Specific Plan -as a specific plan and 2) the New General Plan using the Specific Plan informally as planning guidelines in the P-1 zoning process to implement the General Plan policies relating to the project area. This latter approach is proposed to avoid possible complications and delays in the planning process if a court sets aside the Specific Plan. This dual processing is acceptable because the General Plan includes the same land use designations and planning policies for the project area as the Specific Plan. ' 1 1 . PROJECT DESCRIPTION AND BACKGROUND Proiect Location and Existing Setting The Cypress Lakes and Country Club project site is located in the ' Sacramento-San Joaquin Delta area of unincorpora.;ed north-eastern Contra Costa County approximately 2 .7 miles east of the Town of ' Oakley (see Figure 1) . The project site is located in the off- island portion of the Bethel Island Area, commonly known as the Hotchkiss Tract. The project site is located at the junction of Cypress Road and Bethel Island Road (see Figure 2) , and is generally bordered by Bethel Island Road on. the west, Sandmound Boulevard on the north and east and Rock Slough on the south. The existing use of the site is agricultural (cattie grazing) and ' consists of several fenced pasture areas, with irrigation and flood control canals crossing the property in various locations. Several homes and agricultural structures are located on the ' project site. These structures are primarily located along Cypress and Bethel Island Roads near Sandmound Boulevard. Proiect Characteristics �. The Cypress Lakes and Country Club project would be constructed on approximately 683 acres consisting of five parcels . The project would consist of 1, 301 single-family residential units divided into eleven neighborhoods. In addition, the project would include a 18-hole golf course with amenities, swim and , tennis club, man-made lakes, commercial development. area, recreational vehicle/Boat storage, a day care facility, parks and open space (see Figure j) . The project may be constructed in phases. The phases would be timed to coincide with necessary off-site infrastructure improvements (i .e. sewage, storm drainage, water facilities, roadway improvements, etc. ) . The first phase would include basic grading of the site. Most ' grading would occur in the southern portion of the site for the man-made lakes . Material excavated for the lakes would be used to construct a levee system around much of the project site -for flood protection. This levee system would require FEMA approval before any home constructed on the site could be occupied. 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Residential lot densities would range from a' low .of 3 . 7 units per acre to a high of 8 . 0 units per acre . The overall density of the project is 1 . 9 units per acre. The proposed project also includes a commercial development area (approximately 16 acres) located near the project entry at Cypress Road and Bethel Island Road. The commercial area would be developed in two phases with the first phase being developed between phases one and two of the residential development. The remaining commercial development would occur upon completion of the residential development phases . Anticipated commercial uses could include: grocery store, cleaners, video store, restaurant, professional offices (real estate, insurance, medical etc. ) and a bank. Residential development on the southern portion 'of the site (south of Cypress Road) would include two man-made lakes surrounding the neighborhoods to provide a lake-front living environment . One lake is proposed to be approximately 17 acres while the other would cover approximately 46 acres of the site. A swim and tennis club would also be developed in this area to provide recreational opportunities for project and area residents. In addition, a day care center and public park would be located in this portion of the project site. The residential development north of Cypress Road would include a 18-hole golf course interwoven among the various neighborhoods. A clubhouse facility would also be located in this area as well as a Boaters Club (RV/Boat storage area) . The project applicant also proposes a wetland mitigation area in this portion of the site to mitigate the project' s impacts on wetland areas. (note: The project site contains approximately 9. 18 acres of wetlands. The project would avoid 8 . 23 acres and would mitigate 0 . 95 acres through the creation of replacement wetlands) The major land uses proposed by the project, including approximate acres of coverage, are summarized as follows: 6 SUMMARY OF PROPOSED LAND USES Land Use Acres Single-family Residential (1, 301 units) 25-4 .5 School Site (optional) - 7. 4 Day Care 0.5 Commercial 16.0 Boaters Club 3. 0 Swim and Tennis Club 5. 3 18-hole Golf Course 178.2 Park 21-. 0 Lakes 63 . 0 Open Space 11 .4 Levees 60.4 Drill Sites (natural gas drilling easements) 10 . 3 Wetlands 9.2 Wetlands Buffers & Mitigation 12 . 1 Mayor Streets 30 . 0 TOTAL 682. 3 The primary entrance to the site would be via Cypress Road at the corner of Cypress Road and Bethel Island Road. A secondary access would be provided via Sandmound Boulevard. Cypress Road would be extended into the project site as the primary collector roadway. Residential neighborhoods would be accessed via an internal road system consisting of primary roads, secondary loops and cul-de-sacs to provide access to the individual neighborhoods. In addition to the above mentioned facilities, - the proposed project would also include various on-site and off-site storm drainage, sewage disposal and public utility improvements. On- site storm drainage improvements would include curbs, gutters and drain inlets to an underground conduit system which 'would -be designed in accordance with Contra Costa County Flood Control District (CCCFCD) standards .- The proposed system would pump runoff into the existing Reclamation District (RD) 799 ditch system. The project would include off-site improvements to the ditches as well as on-site retention of storm water in the proposed lakes and detention facilities. on-site sewage facilities would include a gravity sewer system, lift stations and pumps. Sewage from the site would enter the existing force main in Bethel Island Road. off-site expansion of the existing' wastewater system' s land disposal area would be needed. To provide water to the site, off-site improvements including a pump . station and transmission line from Highway 4 - at Cypress Road would be provided. On-site water facilities would include 6", 611 and 1011 underground distribution pipelines. Other utilities, such as electricity and solid waste disposal would be provided by existing facilities or service providers . 7 Proposed Mitigation The proposed project has been designed to reduce certain impacts. The primary mitigation measures incorporated into the project' s design include: a levee system around the project to provide protection from flood hazards (FEMA approval necessary) ; storm drainage improvements including a system of underground storm drains and detention lakes to accommodate runoff from up to a 100 year storm event; avoidance of 8.23 acres of wetlands and creation of a wetland mitigation area to replace 0 . 95 acres of impacted wetlands; dedication of land for a day care center and optional school site; off-site circulation improvements; payment of in-lieu fees equal to $3, 333 per unit for affordable housing; payment of in-lieu fees for County homeless fund; provide funding for a levee encroachment program; and, requirements that project homes exceed energy efficiency standards of Title 24 by 10% . Pr6iect Relationship toRelevantPlans Contra Costa County General Plan, As Amended January, 1991 The Cypress Lakes and Country Club project is located in an area designated on 'the Contra Costa County General Plan .Land Use Map as Agricultural Land (AL) ; however, the project site is within the CountyAurban Limit Line. The project site is located in an area designated as an "Off-Island Bonus Area" which allows increased residential densities under certain circumstances. The Contra Costa County General Plan states the following with regard to residential development on Agricultural Land within the Off- Island Bonus Area (page 3-29) : A bonus density is identified in the "Off-Island" area of the Bethel Island Planning Area east of Jersey Island Road. The base density of this area is I dwelling unit per 5 acres . This density shall be increased through the bonus program if the applicant participates in one of the following programs : Recreational Projects . Residential projects which include a distinct, identifiable recreational character by including substantial recreational facilities shall be allowed a density of 1 . 0 to 2. 9 units per net acre. Recreational reational amenities may include marinas or, launching areas off the project site on Sandmound or Rock Sloughs, a lake- comm'unity, a sailing/boating club on a- project lake, an equestrian facility, a tennis club or golf course. Purchase of Develooment Rights. The development rights for one acre increments of land in the County with an Agricultural Land designation may be purchased and dedicated to the County to increase the base density up 8 1 to 1/2 dwelling unit per n Acquiring , p et acre. Acq g development rights in one acre increments of land in the County with an Agricultural Core designation will , increase the base density up to a maximum of 3 dwelling units per net acre. A program for acquisition of development rights shall be implemented by the Community Development Department . ' The proposed project includes an 18-hole golf course, lakes and a swim and tennis club designed to meet the recreational character , requirements of both the Contra Costa County General Plan and the Bethel Island Specific Plan for increased residential density within the "Off-Island Bonus Area. " In addition, the project ' applicant has indicated an overall residential density of 1 . 9 units per acre which falls within the 1 . 0 to 2 . 9 units per acre. Bethel Island Area Specific Plan, Abril, 1991 ' The Bethel Island Area Specific Plan provides policies and guidelines for development in the project area and vicinity. The Bethel Island Area Specific Plan also designates the land use of the project site as Agricultural Lands and includes the Off- Island Bonus Area designation. The Off-Island Bonus Area would , allow increased residential density of 1 . 0 to 2 . 9 units per net acre for pfojects which demonstrate a recreational character and/or purchase development rights from Agriculture/Agricultural Core lands in the County. ' The proposed- project has been designed to be consistent with the overall planning goals and objectives of the Bethel Island Area ' Specific Plan including: community design in conformance with the designs set forth in the Specific Plan; inclusion of a recreation character (golf course, lakes) ; on-site and off-site , infrastructure improvements; clustered development within the ,allowed density per net acre; internal levee system for flood protection; and provision of limited commercial development area. Discretionary Approvals Required The project applicant has applied for the following discretionary ' approvals by Contra Costa County: compliance with CEQA; rezoning from A-2 to P-1; Preliminary Commercial and Final Residential Development Plan approval; Design Review; and Vesting Tentative map approval . The project may also require LAFCO approval or reorganization and annexation, LAFCO approval may be needed for the reorganization of the Sphere of Influence and annexation of the project site into the Oakley water District for provision of water; and consolidation of the Oakley and Bethel Island Fire Districts in the Bethel Island Planning Area. Other annexation and/or consolidation may be necessary for other services . The ' establishment of a park maintenance district may also be necessary.. Approvals and/or permits may also be necessary from state and federal agencies (e.g. Department of Fish and Game, U. S. Army Corps of Engineers, FEMA, etc . ) . , • 9 2 . CONTRA COSTA COUNTY ENVIRONMENTAL CHECKLIST FORM Background 1 . Name of Proponent Chartered Land and Cattle Company t 2 . Address and Phone Number of Proponent 101 Ygnacio Valley Road, Suite 400, Walnut Creek, CA 94596, (510) 947-1047 ' 3. Date Checklist Submitted -S— 9,Z ' 4 . Name of Proposal, if applicable Cypress lakes and Country Club, File # 2918-RZ, D.P . 3032-90, Vesting Tentative Map #7562 Environmental Impacts by Topic *S *I 1. Earth: Will the proposal result in: a. Unstable earth conditions or in changes .in geologic substructures? S ' b. Change in topography or ground 'surface relief features? S c. The destruction, covering or modification of any unique geologic or physical features? S d. Exposure of people or property to geologic hazards such as-earthquakes, landslides, mudslides, ground failure, or similar hazards? S ' e. Disruptions, displacements, compaction or overcovering of the soil? S ' f. Any increase in wind or water erosion of soils, either on or off the site? S ' g. Changes in deposition or erosion of beach sands, or changes in siltation, deposition or erosion which may modify the channel of a river or stream or the bed of the ocean or ' any bay, inlet or lake? I Discussion ' The project site is located in a geologic area generally characterized as modern sediments of the Delta lowlands. These areas have the following characteristics : "soft, * :ease \o-_L: 's' s: :r-_.s::y �:, ca-_. _s `o :nsigr._°icant 10 1 • *S water saturated muds, peat and loose sands. Muds and peat are unusual and subject to differential settlement under loads. Muds contain expansive clays, some sands may liquify under earthquake stress . " (Contra Costa 'County General Plan, Draft EIR, . Figure VII-7) . The project applicant has prepared a Geotechnical Investigation Report for the project site (see Section 3) . The purpose of this report was to evaluate the surface and sub-surface soils on the site and to provide general recommendations regarding the proposed project. The primary geotechnical concerns identified by this report include : potential liquefaction in near surface sand layers, subsidence and settlement of soils, and seepage under proposed levees . The project site is generally flat ranging in elevation from approximately -5 feet to -8 feet (below sea level) with scattered mounds reaching an elevation of +25 feet. Excavation for the proposed lakes, construction of the levees and other grading would significantly alter the existing topography of the project site. Excavation of the proposed lakes may affect subsurface -geology and create unstable soil conditions. The lakes and related development would also cover a large portion of the project site' s soils. For these reasons, additional environmental review of the project' s impacts on topography, soil compaction, subsurface soils and potential geologic hazards is necessary. Because the project site and surrounding areas are relatively flat, the potential for wind or water 'erosion is generally not considered significant. However, due to the significant amount of soil disruption which would occur with the project (grading and excavation for the proposed lakes) , additional review of potential wind and water erosion impacts is necessary. 2. Air. Will the proposal result in-: . a. Substantial air emissions or deterioration of ambient air quality? S b. Thecreationof objectionable odors? . .ease Xcte: IS' ':s Sicn.' nr Y S:91if:can*-; I:I J S T c. Alteration of air movement, moisture, or temperature, or any change in climate, either locally or regionally? T Discussion The predominate land use in the project area and vicinity is agricultural . Agricultural uses tend to generate little air pollutants other than dust from soil tilling and other particulates from burning crop residues. Some objectionable odors may be created by livestock and composting activities associated with the type of agricultural uses on the project site, but these tend to be minor due to the lack of sensitive receptors (i .e. residences, schools, etc. ) in the area. The most significant source of air pollution in the project area and vicinity is automobile/truck traffic. The project would convert the existing agricultural land use to residential, recreational and commercial land uses . This change in land use would result in additional automobile traffic which may have a significant adverse impact on I.ocal and regional air quality. The primary air pollutants emitted by automobiles include carbon monoxide (CO) and nitrogen oxides (NO,) . Elevated carbon monoxide levels primarily occur on a local level, while nitrogen oxides and reactive )rganic compounds (ROG) react to form ozone, or- photochemical smog, which is a pollutant of regional concern. Traffic resulting from the proposed . project ' would increase carbon monoxide levels primarily at the project entrance (Cypress Road.at Bethel Island Road) In addition, nitrogen oxide levels would also increase contributing .to- regional air quality problems . In addition, the proposed land use change may alter the local climate (e.g. slight changes in temperature and wind patterns) , however these changes would be considered minimal and not significant due to the limited area within which these changes would take place and the abundance of . open space/agricultural uses which border the project site and would regulate the overall climate of the area. For the reasons discussed above, additional review of the project' s impact on local and regional air quality is necessary. Please tote: IS' -s Sian4 -L.-anz. or Pc--enL--'3-'-y slqn4ficant; -'s for .ns' :`:can_ *S *Y 3. Water. Will the proposal result in: a. Changes in currents, or the course of di- rection of water movements, in either marine or fresh waters? ; b. Changes in absorption rates, drainage pat- terns, or the rate and amount of surface runoff? S c. Alterations to the course or flow of flood waters? S d. Change in the amount of surface water in any water body? I e. Discharge into surface waters, or in any alteration of surface water quality, in- cluding but not limited to temperature, , dissolved oxygen or turbidity? S f. Alteration of the direction or rate of flow of=`ground waters? S g. Change in the quantity of ground waters, either through direct additions or with- drawals, or through interception of an - aquifer by cuts or excavations? S h. Substantial reduction in the amount of water otherwise available for public water supplies? S i. Exposure of people or property to water re- lated hazards such as flooding or tidal waves? S , Discussion The project site is located in the Sacramento-San Joaquin Delta area near Sandmound and Rock Sloughs. The area consists of reclaimed Delta lands which are at an . elevation of -5 feet to -8 feet (below sea level) to +25 feet (above sea level) and protected from flooding by an extensive levee system. The existing drainage facilities , on the project site include open drainage channels which traverse the site conveying runoff to the Delta at Taylor and Sandmound sloughs. Presently, domestic water * ':ease tide: S' _ 13 *S *I supplies within the project area and vicinity are primarily provided by wells . ' The proposed project would be susceptible to major flooding if overtopping or rupture of the local levees occurs. To address potential flood hazards the project would include flood control measures (i . e. levees around much of the project site) . In addition, the project would cover over a significant amount of soils with urban uses . This may result in increased runoff and the potential degradation of runoff water quality. However, the proposed project would include a drainage system to accommodate runoff from up to a 100 year storm event through a system of underground drainages and detention lakes. Excavation for the proposed lakes would intercept ' groundwater and require dewatering of the lake sites to complete construction. In addition, groundwater would be the primary source for filling the proposed lakes . For ' these reasons, the project' s potential impact on groundwater will require additional environmental review. The proposed domestic water supply for the project is the Oakley Water District and the sewage collection system would be connected to the Contra Costa Sanitary District #15. Therefore these systems would not affect ground water supplies or ground water quality. For the reasons discussed above, additional review of the ' project' s proposed drainage and flooding mitigation measures, as well as its' potential impacts on the quality of surface water runoff, domestic water supplies (also see item 16) , groundwater and Delta waterways is necessary. 4 . Plant Life. Will the proposal result. in: ' a. Change in the diversity of species, or num- ber of any species of plants (including trees, shrubs, grass, crops, and aquatic plants) ? S b. Reduction of the numbers of any unique, rare or endangered species - of plants? S ' c. Introduction of new species of plants into an area, or a barrier to the normal replenish- ment of existing species? S * D'ease Note: 's' is fcr si- :fcan: _-_en-:a__y significant; '?' _s for. :nsignificant i14 *S d. Reduction in acreage of any agricultural crop? S Discussion Several plants thought to be rare, threatened, endangered or declining ("Special-Status Species") are known to occur in the Sacramento-San Joaquin Delta Region of eastern Contra Costa County. The EIR on the Contra Costa County General Plan identifies 47 plants for which legal protection exists and which occur in the County. Many of ,these plants are known to occur, or have historically occurred, in the - eastern portion of- the County. In addition, the project applicant has prepared a Special- Status Species Survey (see Section 3) for the project site. This study identifies 19 special-status plant species which may occur in the project area. However, during field surveys conducted in May and September of 1991, no special-status plants were found on the project site. In addition, much of the project area consisted of wetlands before the area was reclaimed through the construction of levees and drainage ditches. As a result, some areas exhibit wetland characteristics (i.e hydric soils, wetland plant species) . Wetlands are considered "Waters of the United States" and are protected under the provisions of Section 404 of the Clean Water Act . The project applicant has prepared a wetlands Delineation Revort (see Section 3) which identifies approximately 9. 18 acres of seasonal wetland and drainage -channels on the project site. This calculation of wetland area on the site was confirmed by the U. S . Army Corps of Engineers in a letter dated September 27, 1991 . Theproposed project will result in the conversion of approximately 683 acres of agricultural land to residential, recreational and other urban uses disrupting the existing vegetation on the site and possibly introducing new plant species into , the area (i .e. landscaping) . ' The project may result in a significant loss of agricultural land and may affect rare, thkeatened or endangered plant species as well as 0 . 95 acres of wetland area. However, the proposed project would include a wetland mitigation area to replace wetland areas impacted by the project . Additional environmental review and agency consultation regarding the project' s impact on agricultural land, the introduction of new_ .,ease :ns_�Cn__-ant cLe, s qn4 4 c-.jn: cr a 1'_y 15 *S I plant species, special status plants and the adequacy of proposed wetland mitigation is necessary. 5. Animal Life. Will the proposal result in: ' a. Change in the diversity of species, or num- bers of any species of animals (birds, land animals including reptiles, fish and shell- fish, benthic organisms or insects) ? . S ' b. Reduction of the numbers of any unique, rare or endangered species of animals? S c. Introduction of new species of animals into ' an area, or result in a barrier to the migra- tion or movement of animals? S ' d. Deterioration to existing fish or wildlife habitat? S Discussion ' Numerous reptile/amphibian, bird, mammal and insect species thought to be rare, endangered, threatened or declining ("Special-Status Species") are known to occur in the Sacramento-San Joaquin Delta region of Contra Costa County. The EIR on the Contra Costa County General Plan, January, 1991 (see Section 3) , identifies 52 animals for which legal protection exists and which occur in the County. Many of these animals are known to occur, or have historically occurred, in the eastern portion of ' the County. The project applicant has prepared a Special-Status Species Survev (see Section 3) , for the project site. This study identifies 9 reptile/amphibian, ' 12 bird, 2 mammal, and 16 insect species of special concern as potentially occurring in the project area. According to the applicant' s report, one burrowing owl was sited roosting on the property during one field visit . In addition, the drainage channels may provide habitat for western pond turtle and river otter. The agricultural lands and grasslands present on the project site may provide winter foraging habitat for short-eared owl, black-shouldered kite, northern harrier, golden ' eagle, and/or prairie falcon. Sand dune areas may support California legless lizards and/or Coast horned lizard as well as several dune inhabiting insects of ' special concern. en---..y S:c; ".can_. '_ .s :c: _ns:g.^.__`!ean- 16 *S *I As discussed previously under item 4, the project area also contains wetland areas . wetland areas can .provide valuable habitat for a wide variety of wildlife species depending on the size and quality of the wetland. The project applicant has prepared a wetland Delineation ' Report (see Section 3) , which identifies 9. 18 acres of seasonal wetland and drainage channels on the project. site. The amount of wetland area on the project site has ' been confirmed by the U. S. Army Corps of Engineers in a letter dated September 27, 1991 . The project will result in the conversion of , approximately 683 acres of agricultural land to urban uses (residential, commercial, recreational and open space) . This may result in significant adverse impacts ' on 'special-status . animals and wetland areas as well as. the introduction of new animal species into the area (i .e. dogs, cats and other domestic animals) . In a broader context, the project site is located near the Sacramento-San Joaquin Delta which contains significant fish and wildlife resources. The project may ' result intsecondary impacts on fish and wildlife resources as a result of increased urban pollutants in storm water runoff and increased human use of Delta lands ' and waterways. For the reasons discussed above, the project' s impacts on wetlands, special status animal species and fish and wildlife resources requires additional review and agency consultation. 6. Noise. Will the proposal result in: ' a. Increases in existing noise levels? S ' b. Exposure of people to severe noise levels? S Discussion The major noise source in the project vicinity is traffic on Bethel Island Road and Cypress Road. Noise levels calculated in 1985 along Bethel Island Road between Cypress Road and Gateway were 63 Decibel (dB) at 100 feet . Along Cypress Road noise levels were calculated to ' be 65dB at 100 feet (Contra Costa County General Plan, Draft EIR, page VII-89) . Under the noise and land use compatibility standards of Contra Costa County, * _ease %c_e: _ :.cn - .. Y ' a n:-f-=a-.. s o_ _• �: �.s:g-_. ca- 17 *S *-T— residential uses are "acceptable" within a LDN of 60dB and "conditionally acceptable" within a LDN of 65dB. The proposed project would result in additional traffic on both Cypress and Bethel Island Roads . This traffic, along with other projected traffic, would increase noise levels along these roadways exposing project residents, existing residents along Cypress and Bethel Island roads, and other noise-sensitive receptors in the area to potentially significant noise levels . For -these reasons, additional environmental review regarding the project's impacts on off-site noise levels and noise-sensitive receptors, as well as noise exposure on-site, is required. 7.. - Light and Glare. Will the proposal produce new light or glare? S Discussion Existing' sources of light and glare in the project area include headlights from automobiles traveling on Cypress and Bethel Island Roads and lighting associated with residences on and near the project site. The proposed project will result in additional lighting associated with the residential, commercial and recreational uses being proposed. These new sources of light may result in adverse glare on project residents as well as adjacent residences. Therefore, additional • environmental review regarding the project' s impact on light and glare is necessary (this potential impact will also 'be discussed under Item 18. Aesthetics) . 8. Land Use. Will the proposal result in a sub- stantial alteration of the present or planned land use of an area? S Discussion The proposed project site is designated by the ' Contra Costa County General Plan Land Use Map as Agricultural Land which limits residential development to 1 dwelling unit per 5 acres. However, the project area is also within the "Off-Island Bonus Area" which would allow increased residential density (1 . 0-2. 9 units per net acre) for projects which either contain a recreational character (iie. marina, lake community, equestrian facilities, tennis club, golf course) , or purchase development rights of agricultural land and dedicate- the land to the County. Please Note: IS' is for Significant or Potentially signiticant: ll' -'s for. Insignificant 18 Additional review of the proposed project`s conformance with the "Off-Island Bonus Area" policy is necessary and how it is consistent with the overall Density Cap of not more than 2,909 dwelling units in conjunction with other pending proposals and potential "Bonus" development in the area. Reviert of the project density as it relates to an allocation of dwelling units th.,cmay ')e necessary and can be applied to maintain the overall Density Cap tor development of the "Off-Island Bonus Area". The project would require a rezoning from the existing A- 2 (agricultural use) to P-1 (Planned Unit District) . This rezoning would be consistent under the "Off—Island Bonus Area" program. In addition, � the projects conformance with the various goals, policies and development guidelines of the Bethel Island Area Specific Plan -and the Contra Costa County General Plan (January 1991) , including the requirements of . the 55/35 Land Preservation Plan; the Growth ' Management Ordinance; the Safety Element; the Public Services/Facilities Element; park land dedication requirements; planned trails; and other pertinent policies will be reviewed. 9. Natural Resources. Will the proposal result in an increase in the rate of use of any , natural resources? I Discussion Construction of the Cypress Lakes and . Country Club project will require the use of certain natural resources (i.e lumber and other building materials) . in addition, the operation of construction equipment will require the use of fossil fuels. However, the use of these-natural resources would not be considered inefficient or wasteful and would be similar to other residential construction projects in Contra Costa County. For these reasons, this impact is not considered significant. 10. Risk of Upset. Will the proposal involve: a. A risk of an explosion or the release of hazardous substances (including, but not limited to, oil, pesticides, chemicals or radiation) in the event of an accident or upset conditions? I b. Possible interference with an emergency response pian or an emergency evacuation plan? I * Please Note: '5' is for Significant or Potentially significant;nificant; 'I'. is for Insignificant 9 19 r *S *I Discussion The Cypress Lakes and Country Club project will consist of single-family residences, commercial :and recreational ' uses. Under the requirements of RD 799 the project would be required to submit a revised emergency response plan to address the increased population of the project site. Approval of this plan by the Reclamation District would. be required before any homes could be built on the site. Therefore no significant impact on emergency response plans would occur. In addition, the proposed land uses would not result in the storage of significant amounts of hazardous ' substances . Therefore, no further environmental review. of this topic is necessary. Additional discussion regarding the potential for hazardous materials on the project site is contained under item 17 a & b. The project area is located in an area which contains peat soils . Peat soils. present an unusual safety hazard because they are somewhat combustible ., The potential risks assogiated with development on, or near, peat soils will be evaluated - under potential impacts to fire protection services . 11. Population. Will t1.e proposal alter the location, distribution, density, or growth rate of the human population of an area? S Discussion The proposed project site is located in rural eastern Contra Costa County which includes one city (Brentwood - ' 6, 800 persons) and several unincorporated communities including Oakley (13, 400) and Discovery Bay (4, 800) . The proposed project would result in the development of 1, 301 single-family residential units on the predominately vacant project site. This would constitute a significant increase in population in rural east Contra Costa County. Therefore, additional environmental review regarding the impacts of the project on population distribution (jobs/housing balance) , density and growth rates is necessary. . -ease Xo:e: s y S:q^ can=. _ _s `c_ =ns:gn:_`:can: ' 20 *S *I 12. Housing. Will the proposal affect existing hous- ing, or create a demand for additional housing? I Discussion The proposed project would add 1, 301 residential units to ' the East County area . and would not adversely affect existing housing or create a demand for additional housing. No additional environmental review regarding ' this topic is required. Issues related to the potential affects of the project on the Jobs/Housing balance, densities and growth rates will be discussed under Population, item 11 . 13. Transportation/Circulation. Will the proposal result in: a. Generation of substantial additional vehicular movement? S b. 'Effects on existing parking facilities, or demand for new parking? S c. Substantial impact upon existing transpor- ..tation systems? S ' d. Alterations to present patterns of circula- tion or movement of people and/or goods? S e. Alterations to waterborne, rail or air traffic? S f. Increase in traffic hazards to motor vehicles, , bicyclists or pedestrians? S Discussion The existing circulation system in the project vicinity consists of rural roadways (Cypress Road and Bethel , Island Road) and State Route 4 which is a two-lane State Highway approximately .1 . 6 miles west of the project site. The project would not alter the location of these local circulation routes . The proposed project would result in approximately 13, 500 new vehicle trips per day . This increase would result in a significant increase in automobile traffic on local roadways and State Route 4 . Therefore, additional review Pease \:�:e: 'S' _. __.... _s -s-y^_::ca- 21 ' *S *I regarding the project' s contribution to existing and future (cumulative) traffic and the resulting capacity impact on local roadways, traffic hazards, and bicycle and pedestrian circulation is necessary. Single-family residences would include two parking spaces (garages) which would meet County parking requirements. Parking for the golf course, swim and tennis club, park and commercial areas has not been defined. Therefore, the parking requirements for these facilities needs to be evaluated. The proposed project may include off-site improvements to the local circulation system. These improvements are not ' specifically def'_ned at this time but may affect the present pattern of circulation and will require further review. iBecause of the project' s close proximity to the Delta waterways, it is expected that a portion of the residents of the project would own boats for use on the Delta. Therefore, the project may increase the existing waterborne traffic in Delta waters. The project' s impact on boat traffic on the Delta needs to be evaluated. 14 . Public Services. The following issues address the provision of public services for the project which will require the reorganization of service bound- aries and/or amendments to the Sphere of Influence for a particular agency. Contra Costa County LAFCO is the Respcnsible agency with regard to the reorganization of service boundaries and/or amendments to the Sphere of Influence. Question 14, Public Services, and Question 16, Utilities, summarize the issues most relevant for LAFCO considerations . Will the proposal have an effect upon, or result in a need for new or altered governmental services in any. of the following areas: a. Fire protection? g ' b. Police protection? S c. Schools? S * ?'_ease \oLe: 'S' `_s -'Zr S:cn_`_. :ca^:; :s :c ' 22 *S *I d. Parks or other recreational facilities? S e. Maintenance of public facilities, including roads? S f. Other governmental services? S ' Discussion , Police protection, fire protection and public school services in the project area are currently provided by the Contra Costa County Sheriff' s Department, The Bethel. Island Fire Protection District and Oakley Fire Protection District, and The Oakley Union (K-8) and Liberty Union High School Districts. Maintenance of park ' land, roadways and other public facilities is the responsibility of the Contra Costa County Department of Public Works. ' The project would result in the development of 1, 301 new residential units . The resulting increase in residential structures, urban services and' population may have a significant impact on police protection, fire protection, schools and maintenance services. Therefore, the project' s impacts on public services requires additional environmental review and agency consultation. 15. Energy. Will the proposal result in: a. Use of substantial amounts of fuel or energy? I b. Substantial increase in demand upon existing , sources or energy, or require the development of new sources of energy? I Discussion The Cypress Lakes and Country Club project would require the use of fossil fuels for the operation of construction , equipment, manufacture of materials and long-term commitment of energy to operate the residences, commercial uses and recreational facilities. The amount of energy that would be consumed during the construction and long-term operation of the project would be similar to' other residential communities in Contra Costa County ' and would not be considered adverse because it would not be inefficient or wasteful . For these reasons, no further environmental evaluation of this issue is * ?:ease Kcte: 'S' _s Si cn__.. S`_, _`.:can s fc_ '_r.sicn:ficant 23 , S necessary. conformance with County energy conservation policies and standard building requirements would mitigate any potential energy impacts from the project. 16. Utilities. Will the proposal result in a need for new systems, or substantial alterations to the following utilities: a. Water? - S b. Sewage Disposal? S C. Lighting? S d. Storm Drainage? - S Discussion Domestic water in the project area is primarily provided by private wells . The project applicant is proposing service from the Oakley Water District . To receive water from the Oakley Water District, the project site would need to Iv.e annexed into the Districts Sphere of Influence. The impacts of the proposed project * on available water supplies and the ability of the Oakley Water District to serve the project, should be evaluated. The project site is located within the Contra Costa Sanitary District #15 . -The sewage collection facilities are operated by the Oakley-Bethel Island Wastewater Management Agency. The proposed project would include sewage collection facilities to accommodate development of the site as well as contributions to off-site wastewater disposal area. While the project would appear to provide adequate sewage collection facilities on-site, impacts to off-site wastewater treatment facilities and disposal areas require additional review and agency consultation. The project would include significant new lighting for residential,. commercial and recreational uses . The provision of lighting has not been addressed in the project application and therefore requires additional review and agency consultation. Storm drainage facilities in the project area are operated and maintained by Reclamation District #799 and include two pumping stations located along Sandmound =1ease ','oLe: 'S' ;s tcr --s fcr :nsignificant 29 *S Slough and several open channels crossing the project site. The proposed project would significantly alter the existing drainage pattern of the site and increase storm water runoff from the site. To address this change, the project would include on-site storm drainage facilities including curbs, gutters and drain inlets which would convey runoff to existing off-site drainage facilities. In addition, the proposed lakes would also act as detention facilities . While the project appears to include adequate on-site storm drainage facilities, the project' s impact on off-site drainage facilities and increased storm water runoff requires additional review and agency consultation. . 17. Human Health. Will the proposal result in: a. Creation of any health hazard or potential health hazard (excluding mental health) ? b Exposure of people to potential health hazards? S Discussion Y` Unrecorded' and/or accidental discharge of hazardous materials such as oil, gasoline, diesel and pesticides may have occurred on the project site. The project applicant has 'conducted a preliminary assessment of the project site for the presence of hazardous materials. The potential presence of . these or other hazardous materials could result in health hazards and the need for remediation. Additional review of the project site for the presence of hazardous materials and soil contamination is necessary. An in-depth field investigation may be necessary. Once constructed, the proposed project would primarily consist of single-family residential units, recreational facilities and open space areas. These uses would not be expected to create or expose persons residing within the project, or in surrounding areas, to any health hazards . 18. Aesthetics. Will the proposal result in the obstruction of any scenic vista or view open to the public, or will the proposal result in the creation of an aesthetically offensive site open to public view? S .70-lease Note: 4.s -'Lr si;n:f_*'canz.; -;s fz:- 25 *S Discussion The existing visual setting of the project area is characterized by rural agricultural uses with r-inimal man-made structures (e.g. homes, barns, levees, roads) interrupting views of broad open space. Mount Diablo and the broad views across the Sacramento-San Joaquin Delta can be seen from -several vantage points in the project area. The proposed project would develop approximately 683 acres with residential and recreational uses as well as levees around much of the project site. This development will substantially alter the existing visual character of project site and levee construction may affect certain distant views. Therefore, the visual impacts of the project require environmental review. 19. Recreation. Will the proposal result in an impact upon the quality or quantity of existing recreational opportunities? S Discussion The project site is located in the Sacramento-San Joaquin Delta area which provides significant recreational opportunities (i.e boating, fishing, water sports) . The proposed project would include: man-made lakes, a tennis and swim club, 18-hole golf course, park and open space. While the provision of these recreational facilities would appear to be beneficial, their compatibility with existing recreational opportunities and the "Off-Island Bonus Area" requirements, needs further review. This review should be provided in the land use discussion. 20. Cultural Resources. a. Will the proposal result in the alteration of or the destruction of a prehistoric or historic archaeological site? S b. Will the proposal result in adverse physical or aesthetic effects to prehistoric or historic building, structure, or object? S c. Does the proposal have the potential to cause 'a physical change which would affect unique ethnic cultural values? —S .-ease Note: 'S' s :cr s.q :r :a: .y S:qnca!,:.: I:, for _nsignificar.t 2 *S *I d. Will the proposal restrict existing religious or sacred uses within the potential impact area? S Discussion , The Sacramento-San Joaquin Delta area contains numerous known buried cultural resource sites . ' The project site is located within an area identified on the County' s Archaeological Sensitivity Map as being "Extremely Sensitive" and containing known archaeological sites. Due to the presence of buried cultural resources in the t project vicinity and the potential for encountering cultural resources during site development, the impacts of the project on cultural resources requires additional ' review. 21. Mandatory Findings of Significance. ' a. Does the project have the potential to degrade the quality of the environment, substantially reduce the habitat of a fish or wildlife ' species, cause a fish or wildlife population to drop below self sustaining levels, threaten to eliminate a plant or animal community, re- ' duce the number of restrict the range of a rare or endangered plant or animal or eliminate important examples of the major periods of- , California history or -prehistory? S b. Does the project have the potential to achieve short-term,. to the disadvantage of long-term, environmental goals? (A short-term impact on the environment is one which occurs in a rela- tively brief, definitive period of time while . long-term impacts will endure well into the future. ) S c. Does the project have impacts which are , individually limited, but cumulatively con- . siderable? (A project may impact on two or more separate resources where the impact on each resource is relatively small, but where . the effect of the total of those impacts on the environment is significant. S * ?:ease \ :^_ S. cr 27 , *S d. Does the project have environmental effects which will cause substantial adverse effects on human beings, either directly or indirectly? _ S Discussion Initial review of the proposed project indicates that the project has the potential to degrade the environment, impact biological and cultural resources, achieve short- term goals to the disadvantage of long-term environmental goals, contribute incrementally to cumulative impacts and cause adverse impacts on human being either directly or indirectly. These potential impacts require further review. S' Y SL _._.:an_, S --f _ns ignifi cant 28 3. LIST OF SUPPLEMENTAL DOCUMENTS The following documents have been used in preparing this Initial Study. -These documents are available from the Contra Costa County Community Development Department . The contents of these documents are briefly summarized below. 1. Contra Costa County, "Contra Costa County General Plan", January, 1991. The County General Plan sets forth the broad goals and policies and specific implementation measures which will guide decisions on future growth, development, and the conservation of resources through the year 2005 within the unincorporated portions of Contra Costa county. The General Plan is divided into nine elements including: Land Use, Growth Management, Transportation/Ci rculat ion, Housing, Public Facilities/Services, Conservation, Open Space, Safety, and Noise, These elements provide objectives, principles and standards to decision-making bodies in the County, as well as numerous other.public agencies, that will be making decisions about the development of private and public lands and the locations and extent of infrastructure improvements such as sewers and roadways. 2. Contra Costa County, Final EIR on the Contra Costa County Generall Plan",. December, 1989. The EIR on the County General Plan identifies the potential environmental effect which may result from implementation of the General Plan. *Due to the broad county-wide scope of the plan, the evaluation of potential impacts is less detailed than an EIR on a specific development project . For this reason, it is intended that further environmental review will occur when: 1) the County receives development proposals for parcels within the Planning area; and 2) specific area review projects are undertaken. 3. Chartered Land & Cattle Company, "Special-Status Species Survey", October, 1991 . This study provides information regarding special-status plant and animal species which may be present on the project site. The survey included literature review, consultation with experts and field surveys of the project site. The results of the survey found that no special-status plant species were found on the property during spring and summer field visits . However, several special-status animals. may be present on the site or utilize the site for foraging. 29 4 . Chartered Land & Cattle Company, ,Delineation Report".. July, 1991. This report provides information 'regarding the extent of wetland areas on the project site including a map depicting wetland areas. The report included review of aerial photographs and field surveys conducted in June of 1991 . The report concludes that approximately 9. 18 acres of the project site would be considered wetland and/or subject to U.S. Army 'Corps of Engineers' jurisdiction. The U. S. Army Corps of Engineers has confirmed the findings of the applicant' s wetland delineation Report in a letter dated September 27, 1991 . 5. Chartered Land & Cattle Company, "Geotechnical Investigation Report", December 22, 1988. This report provides information regarding the surface and subsurface soils . on the project site and provides general recommendations regarding the geotechnical conditions present on the site. The report port identifies Your areas of concern and makes recommendations regarding: potential liquefaction on the project site; construction of lakes and levees; potential soil subsidence and settlement; and- underseepage of levees. 6. Contra Costa County, Bethel Island Area Specific Plan, as approved by the Board of Supervisors on July 10, 1989 and ammeded on April 16, 1991 . This plan provides specific goals, objectives and detailed development guidelines for the future development of the Bethel Island area. This plan outlines the land use concepts for the Bethel Island area including concepts for residential and commercial development, parks and open space, * and agricultural uses. Concepts for circulation and utilities are also provided. Specific Development guidelines are also provided including those for: single and multiple family residences; in-fill development; clustered residential development; commercial development; public service; schools; parks; circulation systems; and levees. 30 7. contra Costa County, Environmental impact Report Bethel Island Area Specific Plan (Draft EIR - October, 1989 and Responses to Comments - January, 1990) . The EIR on the Bethel Island Area Specific Plan identifies the potential - environmental effects * which ma} , result from implementation of the Specific Plan. Due to the broad range of actions to be implemented, this EIR was prepared as a program EIR pursuant to Section 15168 of the CEQA Guidelines. It is intended' that as subsequent development projects occur in accordance with the Specific Plan, they will be evaluated to determine whether project impacts will result in effects not examined in the program EIR. 31 4 . DETERMINATION On the basis of this initial evaluation: I find that the proposed project COULD NOT have a significant effect on the environment, and a NEGATIVE DECLARATION will be prepared. I find that although the proposed project could have a sig- nificant effect on the environment, there will not be a significant effect in this case because the mitigation mea- sures described on an attached sheet have been added to the project . A NEGATIVE DECLARATION will be prepared. 0C I find the proposed project MAY have a significant effect on the environment, and an ENVIRONMENTAL IMPACT REPORT is re- quired. Date Signati ReviNed By: 32 i r Appendix B Air Quality Methodology and Assumptions r r r APPENDIX A AIR QUALITY METHODOLOGY AND ASSUMPTIONS CALINE-4 MODEL The CALINE-4 model is a fourth-generation line source air quality model ' that is based on the Gaussian diffusion equation and employs a mixing zone concept to characterize pollutant dispersion over the roadway. Given source strength,meteorology, site geometry and site characteristics, the model predicts pollutant concentrations for receptors located within 150 meters of the roadway. The CALINE-4 model allows roadways to be broken into multiple links that can vary in traffic volume, emission rates, height, width, etc. . The intersection mode of the model was employed for the four intersections studied, which distributes emissions along each leg of the intersection for free- flow traffic, idling traffic and accelerating and decelerating traffic. The intersection model extended 250 meters in all directions. Receptors (locations where the model calculates concentrations) were located at distance of 25 feet from the roadway edge for all four corners of the intersection. Curbside concentrations were for a receptor located immediately adjacent to the roadway. The worst case mode of the CALINE-4 model was employed. In this mode the wind direction is varied to determine which wind direction results in the highest concentration for each receptor. Emission factors were derived from the California Air Resources Board EMFAC-7EP computer model. The computation of carbon monoxide levels assumed the following worst-case meteorological conditions: Windspeed: 1 mps Stability: F Category Mixing Height: 100 meters Surface Roughness: 150 cm Standard Deviation of Wind Direction: 10 degrees The CALINE-4 model calculates the local contribution of nearby roads to the total concentration. The other contribution is the background level attributed to more distant traffic. The 1-hour background level was taken as 2.6 PPM in 1992 and 1.9 PPM in 2005.1 Eight-hour background levels were taken as 1.8 PPM in 1992 and 1.3 PPM in 2005. To calculate 8-hour concentrations from the 1-hour output of the CALINE-4 model, a persistence factor of 0.7 was employed. URBEMIS-3 PROGRAM Estimates of regional emissions generated by project traffic were made using a program called URBEMIS-3. URBEMIS-3 is a program that estimates the emissions that would result from various land use development projects. Land use project can include residential uses such as single-family dwelling units, apartments and condominiums, and nonresidential uses such as shopping centers, office buildings, and industrial parks. URBEMIS-3 contains default values for much of the information needed to calculate emissions. However, project- Bay Area Air Quality Management District, Air Quality and Urban Development-Guidelines, November 1985 (Revised 1991) . r specific, user-supplied information can also be used when it is available. The following is a description of the parameters that were used in the regional air quality analysis of the proposed project: ' -Ambient Temperature: 60 degrees F. -Trip Lengths: Home-Based Other 7.94 miles Home-Based Work 16.34 miles Home-Based Shop 5.18 miles Nonhome-Based Work 8.35 miles Nonhome-Based Other 5.0 miles The above trip lengths were based on MTC estimates of trip length in the year 2000 for the project area.2 An adjustment was made to the URBEMIS-3 output. The URBEMIS-3 program generates estimates of Total Organic Gases rather than Reactive Organic Gases. Reactive Organic Gases were assumed to equal 91% of the Total Organic Gases. S 2 Metropolitan Transportation Commission, Bay Area Travel Forecasts, Congestion Management Program Databook #1: Regional Summary, March 1991 , Appendix C List of Plant Species Observed During Field Surveys PLANT SPECIES OBSERVED ON THE CHARTERED LAND AND CATTLE COMPANY PROPERTY DURING SPRING AND SL IIVIER,-1991, FIELD SURVEYS SCIENTIFIC NAME COMMON NAME Anemopsis californica yerba mansa Amsinckia intermedia fiddleneck Anagalis arvensis scarlet pimpernel Asparagus officianale asparagus Aster exilis annual aster Atriplex patula ssp. hastata henfat Atriplex semibaccata -Austrailian saltbush Baccharis douglasii Douglas's falsewillow Bassia hyssopifolia five-horn smotherweed Brassica nigra black mustard Bromus diandrus rip-gut brome Bromus mollis soft chess ,I Capsella bursa-pastoris shepherd's purse ! Centaurea calcitrapa purple star thistle Centaurea solstitialis yellow star thistle Chenopodium rubrum red goosefoot �. Cirsium vulgare bull thistle Conium maculatum poison hemlock Convolvulus arvensis Morning -glory Cortedaria selloana pampus grass Cotula coronopifolia brass buttons Croton californica California croton Crypsis schoenoides swampgrass Cyperus eragrostis tall flatsedge Cyperus strigosus straw-colored flatsedge Datura stramonium jimson-weed Distichlis spicata salt grass Echinochloa crusgalli barnyard grass Elymus triticoides creeping wild rye Erodium cicutarium filaree Euthamia occidentalis western ragweed Festuca arundinacea reed fescue Festuca pratensis meadow fescue Foeniculum vulgare sweet fennel Frankenia grandifolia var. campestris alkali heath Gilia capitata gilia - Glycyrrhiza lepidota wild licorice Gnaphalium palustre everlasting Helianthus annus common sunflower Heliotropium curassavicum heliotrope Heterotheca grandiflora telegraph weed Hordeum brachyantherum meadow .barley Hordeum geniculatum Meditteranean barley Hordeum jubatum foxtail barley SCIENTIFIC NAME COMMON NAME Hordeum leporinum barley Juglans nigra black walnut Juncus balticus baltic rush Juncus bufonius toad rush Juncus effusus soft rush Lactuca serriola prickly lettuce Layia platyglossa tidy-tips Lepidium latifolium whitetop Lolium multiflorum Italian ryegrass Lotus corniculatus bird's foot trefoil Ludwegia peploides water primrose Lupinus albifrons shrub lupine Malva parviflora cheeseweed Marrubium vulgare horehound Melilotus indicus yellow sweet clover Melilotus officianale alfalfa Oenothera deltoides var. cognata evening primrose Parapholis incurva sickle grass Phragmites australis common reed Plantago lanceolata English plantain Plantago major broad-leafed plantain Poa annus annual bluegrass Polygonum amphibium wireweed Polygonum aviculare knotweed Polygonum lapathifolium willow-weed Polygonum persicaria lady's thumb Polygonum punctatum dotted smartweed Polypogon monspeliensis rabbit-foot grass Populus fremontii Fremont cottonwood Ranunculus sceleratus celery-leaf buttercup Raphanus sativa wild radish Rubus procerus Himalaya berry Rumex crispus curley dock Salicornia virginica pickleweed Salix babylonica weeping willow Salix gooddingii Gooding's willow Salix hindsiana sandbar willow Salix laevigata smooth willow Salix lasiandra Pacific willow Salix lasiolepis arroyo willow Salsola kali Russian thistle Scirpus californicus Bulrush -Scirpus olneyi Olney's bulrush Sida hederacea alkali mallow Silybum marianum milk thistle Sonchus oleraceus sow-thistle Sparganum eurycarpum bur-reed Spergularia rubra rose spurry Spergularia marina salt spurry Tamarix pentandra salt-cedar Trianthema portulacastrum horse-purslane Tribulus terrestris puncture vine SCIENTIFIC NAME COMMON NAME ' Trifolium repens white clover Typha angustifolia nailrod Typha domingensis cattail Urtica dioica stinging nettle Vulpia myuros rattail fescue Xanthium spinosum spiney cocklebur Xanthium strumarium cocklebur 1 . Appendix D Wetland/Landscaping Information iF DELINEATION REPORT CHARTERED ' LAND 1 & 1 CATTLE COMPANY PROPERTY CONTRA COSTA COUNTY, CALIFORNIA JULY 1991 1 Prepared By: Prepared For: Huffman & Associates, Inc. Chartered Land & Cattle Co. 4204 Power Inn Road P.O. Box 430 Sacramento, Calif. 95826 Walnut Creek, Calif. 94597 OBJECTIVE The purpose of this study is to delineate and map the extent of all waters of the United Stites ("waters") , including wetlands, located in the study area, that are subject to the provisions of Section 404 of the Clean Water Act. LOCATION The 700-acre study area is located in northeastern Contra Costa County, south of Bethel Island and Dutch Slough, northeast of Brentwood, west of Holland Tract and Sand Mound Slough, and is bordered on the east by Bethel Island Road (Sections 22 and 23, Township 2 North, Range 3 East; Jersey Island, Brentwood, Woodward Island, and Bouldin Island 7.5 minute U.S.G.S. quadrangles) Figure 1 is a topographic and vicinity map depicting the study area. METHODS AND MATERIALS Field studies were conducted on June 18 and 19, 1991. The "Federal Manual for Identifying and Delineating Jurisdictional Wetlands", was used as the standard for determining whether specific areas are wetlands subject to the Clean Water Act. Corps of Engineers' regulations (33 CFR 328) were used to identify "waters" of the United States other than wetlands, that are present in the study area. The "National List of Plant Species That Occur in Wetlands: California (Region 0) 112 was used to determine the status of observed plants as wetland indicator species. The boundaries of all waters, including wetlands, were mapped in the field onto a ill = 2001 scale infrared aerial photograph .taken on May 15, 1991. All acreages of wetlands .were computed from the aerial photograph by useofa digital planimeter. Detailed data on soils, vegetation and hydrology were - taken in the field. Delineation data sheets are provided in Appendix A. A list of plant species observed and their status as wetland indicator species is provided in Appendix B. Appendix C contains soils information and Appendix D contains delineation map. `Federal Interagency Committee for Wetland Delineation. 1989. Federal Manual for Identifying and Delineating Jurisdictional Wetlands. U.S. Amy Corps of Engineers, U.S. Environmental Protection Agency.U.S. Fish and Wildlife Service,and U.S.D.A.Soil Conservation Service,Washington,D.C. Cooperative technical publication. 311eed,P.B. 1988. National List of Plant Species That Occur in Wetlands:California(Region 0). Biological Report 88(26.10)May 1988. National Ecology Research Center,National Wetlands Inventory,U.S.Fish and Wildlife service,St. Petersburg,Fl. Charter.del FIGURE 1 ; .TOPOGRAPHIC AND VICINITY MAPS v? . a lip A ';4 D:;, S tj IWA N c t: _Y.TCH slovawr pack ..J STUDY. AREA BOUNDARY-.- H 0 44 V. 16.10 U 'H GASB AS F I E �U T C H DUTCH SLOUGH 291 40. % H 0 L L'A 28' v) t rt,. n • % ough PWI Area n d 34 L�o H A L E: T R A C The delineation of wetlands on the site was complicated because of the following factors. 1. Historically, much of the study area was wetlands. Levees and drainage ditches were constructed nearly 100 yea'rs ago for land reclamation. As a -result, relic hydric soils are found over a large area of the site, most of which have been drained. Therefore, the presence of hydric soil characteristics is not a reliable indicator of current conditions. 2. The study area is irrigated for pasture and row crops. Some pasture areas are flood irrigated and contain wetland plant species. Normally, evaluation of soils will indicate whether the wetland vegetation is responding to irrigation or natural conditions. In phis case, however, the soils are not a valid indicator. ' 3 . There are areas on the site which are highly alkaline where the vegetation is dominated by wetland halophytes such as saltgrass and saltbush. Dominance of these species does not always mean that wetland conditions exist, since alkalinity can reduce competition from less tolerant upland species. 4. It is apparent, that wetlands on the site -are sustained by groundwater. We were unable to identify a consistent correlation between depthof saturation and ground surface elevation (See Table 2) as we did at a site on Bethel Island in 1990. Therefore, using ground surface elevations to estimate groundwater depths is not appropriate. A California Department of Water Resoiarces (DWR) groundwater monitoring station is located in the -eastern portion of the site. This station, consisting of monitoring wells 10, 20, 25, and 40 feet deep, provided groundwater, readings at. various times of the year from 1968 to 1990. We graphically plotted the monthly mean groundwater level for each of the groundwater wells over the period of record (Figure 2) . It indicates that the groundwater table is relatively stable throughout the year, varying from approximately 1.75 feet to 2.5 feet, depending on the particular ground,.4ater well. Of particular interest is the average fluctuation of 1.50 feet between January and mid-June when we conducted our field delineation. Charter.del ........................... ............. b ............................. 0 0 44 CA woo Based on the above, we identified saturation within 20 inches (1.50+ feet) of the surface as our standard for a positive hydrologic indicator. Using this standard, we estimated that saturation would be at the surface at the beginning of the growing season. FINDINGS The study area consists of rolling grassland used for grazing and irrigated agriculture. There are also three residences with associated buildings, barns, and fenced areas. Irrigation ditches network the study area with pumps at the southeast and northwest corner of the property, where ditches pump water from Sandmound Slough and Dutch Slough, respectively. There is a large district drainage channel which crosses the center of the property on an 1 east-west axis. Elevation on the study site ranges from 25 feet above sea level to approximAtely -10 -feet mean sea level. Historically, much of this area was a freshwater marsh, and the -soils formed in the accumulated remains of tule, reed, and other aquatic plants. Thin layers of silty mineral matter were added when the marsh flooded. As the mineral base subsided, organic deposits accumulated, and the streams built up bordering alluvial ridges. Hotchkiss Tract (where the study area is located) was reclaimed around.the. turn of the century by levee construction and drainage. Pumping has lowered the water table and allowed the soils to dry; Soils have dried irreversibly so that cracks have developed that remain after rewetting.' These organic soils, which are near or below sea level, have subsided as a result of drying, oxidation, soil blowing, fires, and tillage. The organic-matter content has been diluted as thin layers of minerals have collected in the residual organic soil.' The soils (mapped by Soil Conservation Service) within the study area are comprised of ten soil types including Kingile muck, Rindge muck, Shima muck, Egbert mucky clay loam, Piper loamy sand, Piper fine' sandy loam, Ryde silt loam, Sacramento clay and alkali clay, and Delhi sand. Appendix C contains a soil map of the study area with pertinent soils information. Kingile, Rindge, and Shima mucks are highly organic soils found on the study site. Kingile muck is underlain at a depth of 20 inches 'USDA Soil Conservation Service, 1977. Soil Survey of Contra Coat&County,California. 'USDA Soil Conservation Service, 1977. Soil Survey of Contra Costa County,California. Chatter.del by a substratum of very dark gray and dark-gray, medium acid silty clay. Rindge soils consist of deep, black organic material. Shima ' soils are underlain by sand at a depth of about 16 to 36 inches. Associated with the organic soils on the site are Ryde, Egbert, and Piper soils. Ryde soil consists of stratified mineral and organic layers formed by thick deposits of sediment during several river floods. Egbert soils formed in poorly drained silty clay loam alluvium, and had a thin surface layer of organic matter that oxidized and mixed with the underlying mineral soil. They now have a dark-gray mineral A horizon that contains organic matter and is underlain by gleyed silty clay loam and clay. ' Piper soils formed in windblown material that had encroached on the northwest part of the delta. The surface of Piper soil has. had additions of organic ' material. The B2 horizon has been weakly cemented by carbonates from a fluctuating water table. Sacramento clay and al.-)Cali clay consist of poorly drained and very poorly drained soils that formed in mixed alluvium. These soils are adjacent to the organic soils. Sacramento soils are -used mainly for irrigated row crops on leveled areas and for irrigated pasture. The Sacramento alkali clay contains enough saline and alkali salts to limit selection of crops and type of plant growth. v The Delhi soils formed in wind-modified stream deposits of mixed origin (they are made up of slightly acid to mildly alkaline brown sand) . The types of waters on the property include seasonal wetlands and a channel. A description of each type is provided below. A delineation map with the locations of jurisdictional waters is provided in Appendix D and a summary of ' acreages is provided in Table 1. Seasonal Wetland The seasonal wetlands, measuring approximately 6.52 acres, are present on the study site. These wetlands display several different vegetative compositions. One dominant vegetative cover includes virginia glasswort (Salicornia virginica) and whitetop (Lepidium latifolium) , with plants along the wetland-upland border including Russian thistle (Salsola kali) , and halberd-leaf saltbush (Atriplex ap tula ssp. hastata) . This vegetative cover is underlain by soils with a soil matrix color of 10 YR 4/1 with 10 YR 4/5 mottles and a red calcic horizon at a depth of 12 inches. The f Chaner.del underlying gray silt loam (10 YR 6/1) at a depth of 18 inches is saturated. The wetland-upland border is dominated by the alkali-tolerant (or t halophytic) species including whitetop, russian thistle, virginia glasswort, and halberd-leaf saltbush. The soil matrix color is 10 YR 3/2 with no evidence of mottling or any other hydric soil indicators. Depth of saturation is below 18 inches. During our survey, we investigated several alkali areas supporting similar hydrophytic vegetation as that' found in the delineated seasonal wetland, including saltgrass (Distichlis spicata) , virginia glasswort, saltbush, and seaside heliotrope (Heliotropium curassavicum) . Because these areas lack positive hydrologic indicators, we concluded that these species are present due to these plants' abilities to tolerant alkali conditions. The areas in question are underlain .by permeable soils as observed in the field. Mr. Dalporto., who has farmed the property for fifteen years, stated that water does not pond in these areas for over several days unless an abnormal storm event occurs. Another vegetative cover in seasonal wetlands is dominated by plants such as brassbuttons (Cotula coronopifolia) , Mediterranean barley (Hordeum hvstrix) , and purple sand spurry (Sperctularia rubra) . The soil in these areas is organic to a depth of 14 inches with silty clay loam from 14-18 inches, and sandy loam at 18 inches. Salts are accumulating in the cracks and pores of the soil. Soil is saturated at a depth of 18 inches. The wetland-upland border is dominated by bird's foot trefoil (Lotus corniculatus) and fox-tail barley (Hordeum jubatum) . Soil is organic to a depth of 14 inches with underlying sandy loam which is not saturated at 20 inches. The upland border is dominated by creeping wildrye (Elymus , triticoides) and Mediterranean barley (Hordeum hvstrix) . Soils are organic to a depth of 14 inches with silty clay loam to a depth of 20 inches and sandy loam below 20 inches. The soil is not ' saturated at a depth of 20 inches. In the southeastern corner of the site, a seasonal wetland (SW- 10) is vegetated by a dominance of arroyo and yellow.willows (Salix lasiolepis and Salix lasiandra) . This area is surrounded by irrigation ditches and receives seepage of irrigation tailwater. The existing sandy soils are saturated to the surface. ChaRer.del Channel ` A channel, averaging 20 feet wide for a total of 2.66 acres, is present in the center of the study site. It is used as a district drainage ditch, and receives irrigation water from a main pump at its western extent at Sand Mound Slough. This channel is considered to be waters of the United States since it is a remnant historic natural drainage channel that has been channelized for irrigation use. CONCLUSION Based on our detailed wetland delineation on the Chartered Land and Cattle Company Property,.. we conclude that approximately 9.18 acres are subject to Corps ,of Engineers' jurisdiction under Section 404 of the Clean Water Acta K- delineation map with the locations of waters of the United- States/wetlands is provided in Appendix D. Chatur.del TABLE 1 WETLANDIWATERS OF THE UNITED STATES CHARTERED LAND & CATTLE CO. PROPERTY SEASONAL WETLANDS SW 1 70, 680 sq.ft. SW 2 4,340 sq.ft. SW 3" 2,480 sq.ft. SW 4 1,860 sq.ft. SW 5 1,860 sq.ft. SW 6 1,860 sq.ft. SW 7 74,400 sq.ft. SW 8 19,840 sq.ft. i SW 9 1,860 sq.ft. SW 10 104,780 sq.ft. TOTAL 283,960 square feet or 6.52 acres CHANNEL . CH 1 116,000 square feet or 2. 66 acres RAND TOTAL 399,960 square feet or 9.18 acres Charterl.thl TABLE 2 SOIL SATURATION DATA COLLECTED AT THE CHARTERED LAND & CATTLE CO. PROJECT SITE Depth of Relative 3bservation Estimated Saturated Elevation Point Elevation Soil of Saturation (Feet) (Inches) (Feet) 1 -7.8 60 -12 .8 2 -6.7 0 - 6.7 3 -7 .5 29 - 9.9 4 -9.2 28 -11.5 5 -9. 1 18 -10. 6 6 -6. 0 Below 20 ----- 7 -7.2 10 - 8. 0 8 -7.3 13 8.4 9 -8 .3 20 -10. 0 10 -7.9 18 - 9.4 11 -8.6 27 -10. 9 12 -7.9 28 -10.2 13 -6.7 28 - 9. 0 14 -8.6 24 -10. 6 15 -8.4 25 -10.5 16 -8.3 20 -10.0 17 -8.5 28 -10.8 18 -9.9 25 -12.0 19 -7 .4 30 - 9.9 20 -9. 0 Below 28 ----- 21 -8.8 23 -10.7 22 -7. 4 24 9.4 23 -7. 3 Below 22 ----- 24 -8.9 20 -10. 6 25 -7.7 22 - 9.5 26 -8. 0 20 - 9.7 27 -8. 6 20 -10.3 28 -8.8 22 -10. 6 29 -8 . 6 22 -10.4 30 -8.5 23 -10.4 31 -4 .5 Below 26 ----- Charter.tbl t t ��� s w � �� � s� r r c • ROUTINE WETLAND DELINEATION DATA FORM HUFFMAN & ASSOCIATES, INC. Field Investigator: M'ASOYN. Dain-c->. T. Ulm Date: V3 'TOM 1391 Project: Ckav-+ev,-ga La Tr5l,.egstaI�A county:_ CO '1'5" Wetland Type and Sample Numb r: I A Site condition: (J (J .02tg'aauL 5PV A T-,--st' P)*i- rcl N VEGETATION Dominant Plant Species Indicator Status Associated Plants Hydrophytic Vegetation? Yes: A No: Rationale: 50e7o- FAt1, -P:Ae1)J , RL . SO LS Is soil on hydric soils list? Yes: No: Unknown: Is the soil Mottled? Yes: No: Gleyed? Yes: No: jOY Soil Matrix color: 44, Mottle Color: 10 _ R L4 Soil Texture: J. Other hydric soil indicators: 91-4&1 r Hydric Soil? Yes: )< No: Soil Sample Depth: -3A J m-a-4- ChTOE6L Lu- Y-n 41 1*�l(A. nic(st Soft Rationale: Lou rl,5( 0 HYDROLOGY Inundated? Yes: No: Depth of standing Water: Saturated? Yes::Z- No: Depth of Water: , Other evidence of inundation or saturation: Wetland Hydrology? Yes: R7 No: Rationale: C41(�Ywmrj- &EZREZETZe� 9�� V JURISDICTIONAL DETERMINATION Is the community a wetland? Yes: No: Rationale: cndl'rejo�-s clruwe DclDaLaIrm ROUTINE WETLAND DELT FORM DELINEATION DATA HUFFMAN & ASSOCIATES, INC. Field Investig aj Date: one q Project: T1St County: Wetland Type and Sample Number: -: 13 , Site Condition: VEGETATION - Dominant Plant Species Indicator Status Associated Plants i d ,wrvt E&_ C W ,L ,�- FAC V t .r (_ Hydrophytic Vegetation? Yes: No: Rationale: > -FA eB SOILS. Is soil on hydr is soils list? Yes No: Unknown: Is the soil Mottled? Yes: No: V Gleyed? Yes: No: Soil Matrix Color: 2 Mo-ESN Color: Soil Texture: 1 I, Other hydric soil indicators: Hydric Soil? Yes: No: Soil Sample Depth: Rationale: -} o I HYDROLOGY Inundated? Yes: No: X Depth of Standing Water: Saturated? Yes: No: Depth of Water: Other evidence of i undation or saturation: Wetland Hydrology? Yes: No: Rationale: ' JURISDICTIONAL DETERMINATION Is the community a wetland? Yes: No: Rationale: Uo gnpRihdi? r5 so, kiudvotcrAv v ' i DelDataIrm ROUTINE WETLAND DELINEATION DATA FORM HUFFMAN & ASSOCIATES, INC. Field In V.Nift5. IVIM Date: �fvne 19q) Project: Sta County: Wetland Type and Sample Number:Site Condition: 54dX VEGETATION - Dominant Plant Species Indicator Status Associated Plants U GCPAC UI Hydrophytic Vegetation? Yes: X No: Rationale: > 5-0. o C'. �' �DL ' SOILS Is soil on hydric soils list? Yes:X No: Unknown: Is the soil Mottled? Yes: No: Gleyed? Yes: No: Soil Matrix Color: Mottle Color: Soil Texture: / " • d -! " Otherydric soll indicato s: r �� subs i Scums t' Ovri -, Hydric Soil. Yes: X No: Soil S@Lmpl e Depth: Rationale: ' ao s, ibl� T HYDROLOGY Inundated? Yes: No: Depth .of Standing Water: Saturated? Yes: No: Depth of Water: V9I` Other evi ence of in nd ti n or, satu tion: ' W tland rydrology7 Yes: No: ? Rationale: ' If a JURISDICTIONAL DETERMINATION Is the community a wetland? Yes: No: Rationale: . DeIData.lrm ROUTINE WETLAND DELINEATION DATA FORM HUFFMAN & ASSOCIATES, INC. Field Investigat r• I SO S .0 Date: Project: St County: Wetland Type and Sample Number SLJ - Site Condition: �• VEGETATION Dom'na t P1ant. S ecies Indicator Status Associated Plants �t Hydrophytic Vegetation? Yes: No: Rationale: ' SOILS Is soil on hydric soils list? Yes: No: Unknown: Is the soil Mottled? Yes: No: X Gleyed? Yes: No: Soil Matrix Color: Mot le Color: Soil Texture: Wg4aL& k Igif • Other hydric soilu indicators: Hydric Soil. Yes: No Soil Sample Depth: Z p" Rationale: HYDROLOGY Inundated? Yes: No:-_ Depth of Standing Water: Saturated? Yes: No: Depth of Water: ?X Other evidence of inundation or saturation: Wetland Hydrology? Yes: No: Rationale: ct ' JURISDICTIONAL DETERMINATION Is the communitX a wetland? Yes: No: Rationale: ` al d4�2406 DeINIA.fcm ROUTINE WETLAND DELINEATION DATA FORM HUFFMAN & ASSOCIATES, INC. Field In tiga o : �' S Date.: -` Project: Sta County: A Wetland Type and Sample Number: --G Site Condition: VEGETATION Dominant Plant Species Indicator Status Associated Plants Hydrophytic vegetation? Yes: No: Rationale: 7 C° SOILS Is soil on hydric soils list? Yes: No: Unknown: Is the soil Mottled? Yes: No: leyed? Yes: No: Soil Matrix Color: � e Color: I Soil Texture: �/ ' S' /0 Q p Other hydric soi indicators: Hydric Soil? Yes: No: Soil Sample Depth: Z,2" Rationale: Fes' HYDROLOGY Inundated? Yes: No: Depth of Standing Water: Saturated? Yes: No: Depth of Water: Other evidence of inundati n or saturation: Wetland Hydrology. Yes: No: x Rationale: JURISDICTIONAL DETERMINATION Is the community a wetland? Yes: No: Rationale: A10 42dtaiaiAt j'nd4.eT"-6"-V M40 i. DdDatalrm " 1 i t r r r PARTIAL LIST OF PLANTS OBSERVED ON THE CHARTERED LAND & CATTLE CO. PROPERTY AND THEIR STATUS AS WETLAND INDICATOR SPECIES Scientific Name Common Name Statusl&2 Atri)2lex patula ssp. •hastata halberd-leaf saltbush FACW Avena bar ata wild oats UPL Brassica nigra black mustard UPL Bromus diandrus (B. rigidus) rip-gut grass UPL Bromus mollis soft chess FACU- Centaurea solstitialis yellow star-thistle UPL Chenopodium rubrum red goosefoot UPL t Cirsium vul acarre bull thistle FACU Conium maculatum poison hemlock FACW 1 Co_ tufa coronopifolia brassbuttons FACW+ Cynodon dactylon bermuda grass FAC CXperus eragrostis tall flatsedge FACW Distichlis spicata inland saltgrass FACW* Elvmus triticoides creeping wildrye 'FAC Euthamia occidentalis western ragweed OBL Festuca arundinacea reed fescue FACU Frankenia arandifolia alkali heath FACW Heliotropium curassavicum seaside heliotrope OBL Hemizonia pungens common tarweed FAC Hordeum geniculatum Mediterranean barley NI Hordeum hystrix Mediterranean barley FAC Hordeum jubatum fox-tail barley FAC+ Hordeum leporinum barley NI Juncus bal� It cus baltic rush OBL Juncus bufonius toad rush FACW T � Juncus effusus soft rush OBL Lactuca serriola prickly lettuce FAC Lepidium latifolium whitetop FACW Lolium gerenne perennial ryegrass FAC Lotus corniculatus bird's foot trefoil FAC Parapholis incurva sickle grass OBL Picris echiodes bristly ox-tongue FAC* Polygonum amahibium water smartweed OBL Polygonum aviculare prostrate knotweed UPL Polynogon mons.peliensis rabbit's foot grass OBL Pooulus fremontii Fremont cottonwood FACW Raphanus sativus wild radish .UPL r Rubus procerus himalaya berry FAC 1Reed, P.B. 1988. National List of Plant Species That Occur in Wetlands: California (Region 0). Biological Report 88(26.10) May 1988. National Ecology Research Center, National Wetlands Inventory, U.S. Fish and Wildlife Service, St. Petersburg, Fl. 20BL = obligate; FACW = facultative wetland; FAC t facultative; FACU = Facultative upland; UPL = upland; and NI = no indicator. Charter.plt Scientific Name Common Name status Rijmex crispus curly dock FACW- ri Salicornia virginica virginia glasswort OBL Salix lasiandra yellow willow OBL Salix lasiolepis arroyo willow FACW Salsola kali Russian thistle FACU+ Scirpus olnevi olney OBL Sparganum eurycarpum giant bur-reed OBL Speraularia marina saltmarsh sandspurry OBL Spergularia rubra purple sand spurry FAC Trianthema Portulacastrum desert horse-purslane FACW Trifolium fragiferum strawberry clover NI* Typha latifolia cattail OBL Urtica dioica stinging nettle FACW Vulpia bromoides six-weeks fescue FACW Xanthium spinosum spiny cocklebur UPL Charter.plt 1 A r s t t t STUDY AREA - •bw3� �• het lslond c':::.,�:�.• ,:; '' SGOUCH..:r. $ems y •tip., r;1-. ,;:tr. Pe: .2 Ea r...+. r. r.: {. r ^i•, ' `•i.::" . '� ,r,:,y,,, a '. .�: .. Phi 'p•. : ax L, x. +...{ fc 1 Fc DOC Pe `` Ca DOC '' °;- �• a e; DOC .'.;`_ 5,.• Fc t '6'"E ..Y� ';:t PhS; ':�:R a '•i'.' i�' r ' 'iFMli.'. Rh Pe Fe ' �• T Pe 0y` Es i s Pi \•f' :. oFc Ei 1. t''.. :Pe ir. Ph ..r"" N•. r. f.; pe c a a: Po C 1.. Zia D.:: �' ��e��j•�,;�i�F{.4�SN►1F. r'W•71'ft. ZJSDA, Soil Conservtra Costa county# California. Soil Survey of Contra 1 �I ��g 1 1 1 1 1 i 1 Y AREA r Map Symbol Mapping Unit Order DaC Delhi sand,. Entisols 2 to 9% slopes I� Ea Egbert mucky Mollisols clay loam Kb Kingile muck Histosols Pe Piper loamy Inceptisols sand Ph Piper fine Inceptisols sandy loam Rd Rindge muck Histosols Rh Ryde silt loam Mollisols Sa Sacramento clay Mollisols Sb Sacramento clay, Mollisols alkali Se Shima muck Histosols �i USDA,Soil Conservation Service, 1977. Soil Survey of Contra Costa County,California. Charter.sol ' THE WETLAND DELINEATION MAP IS AVAILABLE FOR REVIEW AT THE CONTRA COSTA COUNTY PLANNING DEPARTMENT. 1 i - DEPARTMENT OF THE ARMY U.S.ARMY ENGINEER DISTRICT,SACRAMENTO CORPS OF ENGINEERS 1325 J STREET REPLY TO SACRAMENTO,CALIFORNIA 958142922 ATTENTION OF September 27, 1991 Regulatory Section (9100843) � Ms. Lynn Jochim Chartered Land and Cattle Company P.O. Box 430 Walnut Creek, California 94597 Dear Ms. Jochim: This letter concerns the project known as the Chartered Land and Cattle Company property, located in Sections 22 and 23, Township 2N and Range 3E, Contra Costa County, California. We have reviewed and verified the wetland delineation map of the Chartered Land and Cattle Company property submitted to us by letter dated August 8, 1991. Our jurisdiction in this area is under Section 404 of the Clean Water Act. A Department of the Army permit is required prior to the placement of dredged or, fill material into waters of the United States. Accordingly, a permit will be required prior to filling any of the 9.18 acres of waters present on the Chartered Land and Cattle Company site as identified on the verified wetland map. The type of permit processing required will depend on the type and amount of waters which would be lost .. or substantially adversely modified by fill activities. This verification is valid for three years from the date of this letter. Please refer to identification number 199100843 in any future correspondence concerning this project. If you have any questions, please write Karen Shaffer at the letterhead address, Room 1444, or telephone (916) 557-5269. Sincerely, Tom Coe Chief, Regulatory Unit 1 Copy Furnished: Huffman & Associates, Inc. , Mr. James Gibson, 4204 Power Inn ' Road, Sacramento, California 95826 i HuFFMAN & ASSOCIATES, INC. Wetlands Regulatory Consultants ' Maim Office Sacramento Office 700 Larkspur Lending Circle 4204 power I M Road suito 100 Sacramento, GA 9!826 ' Larkspur, CA 94939 (916) 732.2050 (415) 925.2000 (916) 732.2051 Fax (415) 925.2066 Fax (916) 732.2055 AllJust 28, 1991 ' Ms. Karen Shaffer Regulatory Section U.S. Army Corps of Engineers 1'125 a Street Sacramento, California 95614 iSubject: Wetland Boundaries utilizing the 2987 Delineation Manual - Chartered Land and Cattle Company Property, Contra Costa County, California Dear Ms. Shaffer: This is in response to our conversation on August 26, 1991 concerning revel t directives. from Washington requiring that, as of August 17, 1991, wetland delineations should be conducted and evaluated utilizing the 1987 Waterways- Experi7nent Station Wetland Delineation Manual. ' We have reviewed our wetland delineation of the Chartered Land and Cattle Company, which utilized the 1989 Unifiad Federal Methodology. We have also reviewed the 1987 manual and determined that the delineation of wetlands on the property is substantially the same by applying the 1987 manual criteria. Therefore, please consider our wetland delineation consistent with the 1967 manual. Our client has agreed to this Finding. Chartprt.ltr Ms. Karen Shaffer August 28, 1991 Page 2 ' ' We look forward to conducting our tield verification with you on September 4, 1991. If you have any questions, please call me at (916) 732-2050. Sincerely, James C. Gibson Senior Vice President Huffman & Associates, Inc, JCG:b*t cc: 714s. Lynn Jochir Chartered Land & Cattle Co. 101 Ygnacio Valley Road Suite 400 �. , Walnut Creak, California 94596ij charterl.ttr r r r r r DRAFT ' HABITAT MITIGATION AND MONITORING PLAN FOR THE r. CYPRESS LAKES GOLF AND COUNTRY CLUB PROJECTS CONTRA COSTA COUNTY (AUGUST 1992) 1 r 1 r r r 1 1.0 PURPOSE The purpose of this document is to set forth a conceptual plan to compensate for project-induce'd 1 wetland impacts associated with the Cypress Lakes1l Golf and Country Club located in,Contra Costa County, approximately 2.7 miles east of the community of Oakley, California. 2.0 MITIGATION GOALS AND OBJECTIVE,S This plan has been designed to conform withPederal and State policies pertaining to 11 1 compensatory mitigation. It has been designed so thA compensatory mitigation would occur on- site and the type of wetlands to be created would be'of the same type and value as those which would be impacted (in-kind mitication). The ratio of wetlands to be created for each acre impacted was designed to be sufficiently high to assure that there would be not net loss of functional wetland value. 3.0 WETLANLID IMPACTS 3.1 Existing Wetlands A wetland delineation of the project area was completedI by Huffman and Associates, Inc. on July 17, 1991. Their findings are set forth in "Delin�Mtion Report, Chartered Land and Cattle Company Property, Contra Costa County, California," July 1991. This report concludes that there is a composite total of 9.18 acres of waters of the United States, including wetlands, existing on the property. Of this total, approximately 6.52 acres are wetlands while the 11 remaining 2.66 acres is a channel. The Corps of Engineers field verified the wetland delineation as indicated by their letter dated September 27, 1991111. The 6.52 acres of wetland is comprised of several different community types. One type is dominated by glasswort Salicornia vireinic ) and whitetop pepper grass (Lel2idium latifoliut ) with Russian thistle (Salsol kali) and halberd-leaf��salt bush (Atriplex pgula spp. hastat ) becoming dominate near the transition from wetland to upland. Another type is dominated by brassbuttons Cotula coronopifolia), Mediterranean d H l barey ( oreurn hl,. 11 Lrix) and purple sand spurry (Sper,ularia rubra with bird's foot trefoil.I(Latus corniculate ) and foxtail barley (Hordeum jubaturn) becoming dominant near the transition from wetland to upland. A willow scrub riparian wetland is located in the southeastern corner of the project area. The vegetation in this wetland is dominated by arroyo willow (&IjA lasiole2is) and yellow willow (Salix lasiandra . ii Cyprcss.rpt EI £0 'd 09699E1.916 'ON XVJ it i' 11,I)J0IS 0 u0sq!q K:cj 03M The first two wetland community types can be characterized as alkali meadows dominated with alkalia-tolerant (or halophytic) species. The hydrology which supports these wetlands is predominantly ground water au,mented by localized surface water. The willow dominated wetland is sustained by seepa e of irritation tail waters from adjacent ditches. 4.2 We Im acts As proposed, the project would eliminate an estimated 0.75 acre of the 6.52 acres of wetlands currently existing within the project area. The wetlands which would be impacted are alkali meadows. The largest of those alkali meadows would be preserved while the smaller alkali meadows would be impacted. A relatively sinall area of the willow scrub wetland would be impacted by flood control levee construction. 4.0 PLAN' SPECIFICS As stated previously, this mitigation plan provides for on-site, in-kind mitigation of wetland impacts at a ratio of wetland created per acre impacted sufficient to assure that there would be no net loss in wetland functional value. This mitigation plan provides for the creation of 2.28 acres of alkali meadow wetland to compensate for the 0.75 acres of alkali meadow which would be eliminated. These wetlands would be created adjacent to, and in expansion of, the existing alkali meadow wetlands which would be preserved. These wetlands would be created by excavating adjacent uplands to a depth four to six inches lower than the existing ,,wetlands. The top eight inches of soil in wetlands to be impacted will be salvaged and then placed in the created wetlands to serve as inoculant The wetlands to be presencd, as well as those to be created, have been designed with a natural buffer to minimize perturbation from surrounding development. These buffers will, as a minimum, be at least 50 feet in width, however, it will range up to approximately 200 feet in width. These buffers will be maintained in as natural as state as possible. Mowing, watering, planting of exotic vegetative species, etc. will not be allowed. Figure is a plan of the project showing the location of wetlands to be preserved and created along with their buffers. As can be seen in �r P Figure the reserved and created wetlands will,be surrounded by golf g course. In order to minimize potential impacts which could result from runoff from the golf course it will be designed so that the runoff from greens, tees, and fairways is directed away from the preserved and created wetlands and their buffers. Cypress.rpt b0 'd 09699u19I6 'ON Xdd 1QP'ojs ' uos9!0 6'c.cl Q?s? 716-6!_nON The preserved aid created wetlands as well as th eii buffers. will be fenced during construction activities in order to avoid the possibility of inadvertent I impacts from construction in adjacent areas. In addition, a construction-please sedimcnt :control plan will be developed to minimize sediment transport from disturbed surfaces. i , 5.0 SCITEDULF, FOR nIPLEMENTATION A detailed mitigation plan which includes construction ion specifications incorporating the criteria contained in this conceptual plan will be submitted rto' and approved by, Contra Costa County prior to beginning any construction activities. The created wetlands will be constructed prior to initiatinc,construction of the developed portion of the project. 6.0 N'10 NNI TO R I ING All created wetlands will be monitored for a period of fiveyears or until the success criteria have been met, whichever is later. Quantitative vefttation data, as well as hydrology data will be collected and recorded on standardized data sheets. Aerial photography will be obtained for assessing areal extent of created wetlands. In addition, permanent photo points will be established to monitor vegetation trends qualitatively. The preserved wetlands will also be monitored. Monitoring of the preserved. wetlands as controls will provide a means of assessing variations resulting from abnormally wet or dry years, should they occur during the monitoring period. i{ Monitoring efforts will serve to: a. determine annually the need for supplemental seeding. If percent cover criteria :1 are not being achieved, additional seeding may be necessary;, b. determine the necessity of weed control!i If weedy species are interfering with the establishment of desired species, control measures may be necessary; and C. determine whether there is a need to physically modify the created wetlands or construct additional wetlands. A monitoring report will be submitted to Contra Costa�County annually following each growing season. The monitoring report will present the results o' f the field monitoring, assess the relative it Cyprcss.rpt J'ePJC)JS )R UOSq!q o9699CL916 '011 XVJ Ql ! H A success of the mitiLgation to date, and identify any corrective measures necessary to achieve success. Results of.the five-year monitoring program will be evaluated to determined the success of the wetland mitigation effort. If results indicate that the success criteria have been met or exceeded, no further monitoring will be required. In the event that the success criteria are not being achieved and minor modifications can be made to correct the deficiencies, the modifications will be made and monitored for an additional two growing seasons. If the monitoring results indicate that the specification criteria have been met, no further monitoring will be required. 7.0 SUCCESS CRITERIA The following criteria must be equalled or exceeded in order for the mitigation to be deemed successful. 1. At least 2.28 acres of wetlands must be constructed in accordance with the procedures outlined earlier in this plan. 2. At least 2.28 acres will be dominated by vegetative species occurring in the preserved wetlands. I The vegetative cover within the 2.28 acres of created wetlands will be at least 80:'0 of that of the preserved wetlands. 8.0Ole• - L G TEIti 1141AL\TEN.' �\CE This mitigation plan has been designed so that the preserved and created wetlands will be self- sustaining and will not require maintenance to assure their continued viability. None-the-less, some sort of maintenance may be required to respond to perturbation by man. For example, if unauthorized dumping were to occur within preserved or created wetlands or their buffers, maintenance would be required in order to clean up the dumping and properly dispose of the material. Following successful establishment of the created wetlands, a homeowners district or similar mechanism will be established and funded to carry out any maintenance needs that may arise. CYpress.rpt 90 'd 09699£L916 '011 XV3 IPP101S UOSOM 1£:C1 r-m ft lUl� • =111IN► : ►moo► ��r►I'Iil�� M1 tl����� �� ►�illlllltl//l�II i WE Isom DID ► s►.�� •nu•'� : ►:;now • sp- vim NO 50, PIP Ro off WE IVA OAF on VOL •,�. LANDSCAPE CRITERIA Overall Concept ' The overall landscape scheme shall be in keeping with the existing character of the area. Vegetation shall be kept low and consist predominantly of grass and wildflowers with some introduced shrubs and trees. Tree massing will occur where screening is necessary for noise and visual buffer zones (i.e. , around outside of project levee) . Irrigation shall be kept to a minimum and used only in ' special areas where increased water is necessary to achieve desired planting effects. ' Plant Materials The soils in the project area consist mainly of sand and clay. The following plant materials and tree species can thrive under the existing soil conditions and are recommended: . Low Growing Grasses as Leciumes ' Latin Name Common Name Comments Briza maxima Quaking Grass (A) White flower ' Bromus mollis Blando Brome (A) Good erosion control Lotus corniculatus Bird's-Foot Trefoil (P) Deep rooted Pennisetum setaceum Fountain Grass (P) Clumping grass Trifolium tragiferum O'Connors straw- (P) Good erosion control berry clover Low Growing Wildflowers Achillea millefolium White Yarrow (P) Fast cover Centaurea cyanus Bachelor Button (A) Tolerates drought Chrysanthemum Ox Eye Daisy (P) Full sun/part shade ' leucanthemum Eschscholzia California Poppy (A,P) Easily established californica ' Lasthenia chrysostoma Dwarf Goldfields (A) Fast cover Lupinus bicolor Pigmy-leaved lupine (A) Attractive blue flwrs Nemophila menziesii Baby Blue Eyes (A) Fast cover Oenothera hookeri California Evening (P) Sherry Red flowers Primrose Phacelia tanacetifolia Lacy Teavea Phacelia(A) Hardy, reseeds well (A) = Annual (P) = Perennial ' is\wl2\client\19018\deir\landscap.doc r Shrubs and Trees Latin Name Common Name . Alnus rhombifolia White Alder , Platanus racemosa California Sycamore Populus nigra NItalida^' Lombardy Poplar Quercus agrifolia Coast Live Oak Salix babylonica Weeping Willow Umbellularia Californica California Bay Celtis occidentalis Common Hackberry Eucalyptus citriodora Lemon-Scented Bum , Eucalyptus camaldulensis Red Gum Malus cvs. Flowering Crabapple Phoenix canariensis Canary Island Date Palm ' Pistacia chinensis Chinese Pistache Platanus acerifolia London Plane Tree Populus nigra ^'Italica" Lombardy Poplar Pyrus calleryana Ornamental Pear Pyrus communis cvs. Common Pear Washingtonia robusta Mexican Fan Palm Tree Species Trees shall be limited to special areas such as recreational areas, at the ' project entrance, along the neighborhood park, around the outside of the project levee and as buffers or screens where needed. Tree species shall , not be randomly mixed but reflect an organized, identifiable pattern. Spacing intervals should be no greater than 35 to 40 feet on center. Sight lines at the project intersections shall be kept clear of plant materials that could obstruct vision. Irrigation All landscape areas shall have an irrigation system capable of sustaining ' good plant growth. The system shall be designed in order to ensure efficient water management and control. Automatic water conservative , system should be considered. Temporary systems may be utilized in public areas to help establish plants. As a mitigation measure state that final landscape guidelines will be prepared consistent with these criteria prior to final map approval. ' is\vo12\c1icnt\19018\deir\1andscap.doc —2— , ORDINANCE NO. 90- s� (Water Conservation Landscaping in New Developments) The Contra Costa County Board of Supervisors ordains as follows (omitting the parenthetical footnotes from the official text of the enacted or amended provisions of the County Ordinance Code): SECTION I. SUMMARY. This ordinance provides for water conservation landscape requirements in new developments. SEfpgN II. Chapter 82-26 is added to the County Ordinance Code to read: CHAPTER 82-26 WATER CONSERVATION A P W DEVELOPMENTS ENTS ' ARTICLE 82-26.2 GENERAL 82-26.202 Water Conservation Landsca2ing. All land within the unincorporated area of Contra Costa County shall be subject to the provisions in this chapter. ' (Ord. 90-59). 82-26.204 Intent and Findings. (1) Landscaping irrigation accounts for approximately fifty percent of all water used in urban areas. Water conserving landscapes use only about one-third of the water of a traditional non-water conserving landscape. (2) Water in the County is of limited supply. The County is growing in population. In order to meet the growing demand for water supply, water conservation measures need to be implemented. (3) Water, as a valuable and limited resource, should not be wasted. The County has played a lead role in protecting Bay and Delta water quality, and in advocating water conser.,ation before considering new water supply projects. ' (4) Water conservation measures will save money and can be accomplished without degradation of iesthetic values of developments. (5) For all of these reasons, it is in the interest of the public health, safety and welfare ' of the County to require water conservation methods for landscaping of new developments by regulating turf areas, planting materials, and irrigation practices. (Ord.9059). ' 82-26.20 Regulations. The Board of Supervisors may issue regulations for the administration of this chapter, including procedures and policies. (Ord. 90-59)• ' ARTICLE 82-26.4 APPLICATION AND REOU REMENTS B2_-2L_-_4_Q2_ Application to New Developments. (1) Water conservation landscape requirements shall apply to all new single family residential developments having common areas, including landscaped front yards, or model homes, and to all other new developments. (2) If a single family residential development has common areas, the water conservation landscape regulations shall apply to all common areas. The landscaping of front yards as part of new development will be considered as common area, and will be subject to the requirements outlined in this chapter. (3) If a single family residential development has one or more model homes, at least one model home in the development must be planted in accordance with water conservation requirements. ' 1 ORD. NO. 90-S t l (4) Conditions of approval for new development subject to the provisions of this chapter shall require landscape Plans to be submitted to the Community Development Department for final review and approval prior to the issuance of a building permit. (Ord. 90-SE)). S2-26,404Renuirements- (1)Turf Maximums. Turf areas shall not exceed twenty-five (25) percent of planted area in all developments subject to this chapter. Where turf is an essential part of the development,as in school playing fields or in public parks,a higher percentage may be allowed. No turf shall be allowed in median strips or in areas less than eight (8) feet wide. (2) Drought-Tolerant Plants. At least ninety (90) percent of the plants in tion-;:iri area shall be low-water-requiring, drought-tolerant plants approved by the Community Development Department. A low-water-using,drought-toleran:plant includes species suited to local climate and requires little or no irrigation in order to thrive. The remaining planted area (up to ten (10).percent) can be used for non-drought-tolerant varieties if they are grouped together and can be irrigated separately. (3) Mulch. A minimum of two inches of mulch shall be added to the soil surface after planting. Non-porous material shall not be placed under the mulch. (d) Irrigation. (a) Sprinklers and sprays shall not be used in areas less than eight (8) feet wide. Drip and bubbler systems shall not exceed one and one-half(1.5)gallons per minute per device. (b) Sprinkler heads with a precipitation rate of.85" per hour or Iess shall be used in slopes exceeding fifteen percent or slopes exceeding ten percent within ten feet of hardscape to minimize runoff. (c) Valves and circuits shall be separated based on amounts of water required for each area. (d) Drip or bubbler irrigation systems shall be required for trees that cannot be sustained by ground or rain water. (e) Sprinkler heads shalt have matched precipitation rates within each control valve circuit. (f) Serviceable check valves shall be required where elevation differential may cause low head drainage. (g) Sprinkler head spacing shall be designed for head-to-head coverage. The system shall be designed to provide minimum runoff and overspray onto non-irrigated areas. (h) All irrigation systems shall be equipped with a controller capable of dual or multiple programming. Controllers shall have multiple cycle start capacity and a flexible calendar program. (5) Ornamental-Pond . Fountains, ponds or other water bodies that are part of the landscaping for new developments are discouraged and shall be restricted as set forth in this sub- section. Unless the water body is an integral part of the operation of the new development, the surface area of the water body shall be counted as turf in calculating maximum allowable turf for the landscaped area. Where well water or untreated water is used and the water supply is recirculated, the Community Development Department may make allowances consistent with the other provisions of this chapter. z ORD. NO. 90-5 9 (6) Landscape plans shall indicate the total landscape area, the area and percentage of drought-tolerant planting and the area and percentage of ornamental non- drought-tolerant plantings. The plans shall be certified as being in compliance with this chapter by a licensed landscape contractor,architect or other landscape professional whose qualifications have been approved by the Community Development Department. Landscape plans shall include the following: (a) A water budget which includes estimated annual water use(in gallons)and the area (in square feet)to be irrigated; (b) Precipitation rates for each valve circuit; (c) A monthly irrigation schedule for the plant establishment period and the Mowing year. (7) Additional Requirements in Residential Developments. (a) In residential developments with one or more model homes, at least one model home in the development must be planted with drought-tolerant plans with a maximum of twenty-five(25)percent turf and/or water area. (b) The-developers shall provide each buyer with sample landscape plans using drought-tolerant plants with a maximum of twenty-five (25) percent turf area. (c) Subject to Community Development Department approval, the developer shall distribute outdoor water conservation pamphlets to each buyer at the time property is sold. Such pamphlets may be obtained from local water districts, from the State Department of Water Resources, or from the Community Development Department. (Ord. 90-5�. SECTION M. Chapter 916-2 of the County Ordinance Code is amended by adding Section 916- 916-2.004. Water Conservation}Landscaping. Landscaping of property subject to this title shall conform to the water conservation requirements of Chapter 82-26 of this Code. (Ord. 90-59) SECTION IV. EFFECTIVE DATE. This ordinance becomes effective 30 days after passage, and within 15 days of passage shall be published once with the names of supervisors voting for. and against it in the Contra Costa Times, a newspaper published in the County. PASSED ON July 31, 1990 by the following vote: AYES: Supervisors Powers, Schroder, ?IcPeak, Torlakson and Fanden NOES: None W' ABSENT:None ABSTAIN: None ATTEST: Phil Batchelor, Clerk of the Board of Supervisors and County Administrator 1 By01 Depu Boar Chair 3 ORD. N0. 90- .59 /S /z g p/'�o3:. t) R. 11: CYPRESS LAKES & COUNTRY CLUB T VT LANDSCAPE GUIDELINES FOR INTERNAL LEVEE These Guidelines shall be utilized in preparing the final landscaping plan for the internal levee proposed by the Cypress Lakes & Country Club project. These Guidelines were prepared consistent with the Interim Guide for Vegetation on Flood Control Levees Under Reclamation Board Authority (September 18, 1988) prepared by the State Reclamation Board. This Interim Guide is still in effect. The Reclamation District-799 is responsible for maintaining the existing levees on Hotchkiss Tract. According to FEMA requirements, a governmental agency or entity must maintain the proposed internal levee around the Cypress Lakes project. RD-799 may agree to accept maintenance of the internal levee. If not, a governmental agency or entity will be formed or selected to maintain the levee. On levees under the authority of a reclamation board, all landscaping projects must have an approved board permit prior to the start of landscaping work. If RD-799 accepts maintenance responsibility for the levee, the final landscaping plan will be submitted as part of the permit application. If responsibility is accepted by another government . agency or entity, a final landscaping plan will be prepared prior to the commencement- of landscaping work. A. Trees 1. Trees may be planted on unrevetted levee slopes, and on levee slopes above revetment. 2. - Trees shall be spaced to allow thorough visibility of the levee slope and toe from the crown roadway. Spacing and number of trees will be considered as it relates to the ability to conduct routine maintenance and emergency flood fighting activities. 3. Factors such as the levee structure and the area of protection will be considered prior to issuing a permit for landscaping. 4 . . The lower foliage of trees on the levee slopes shall be pruned and maintained to a minimum of 5 feet above ground level so as to provide visibility beneath the trees along the levee slope for maintenance purposes. 5. Trees planted adjacent to the 10-foot maintenance zone at the levee toe shall be pruned to a 12-foot vertical clearance and in such a manner as to allow for the unimpaired passage and operation of maintenance equipment. 6. Species of trees should be selected whose mature height does not exceed 50 feet. 7. No fruit or nut trees will be permitted on the levee slope or within 25 feet of either levee toe. B. Shrubs 1. Shrubs or any other form of woody or herbaceous vegeta- tion which grows in a solid, closed form and which' does not lenditself to be pruned into a single trunk will not be permitted on levees. C. Ground Covers 1. sod, grasses, and other nonwoody ground covers are encouraged on the slopes of all levees under Reclamation Board authority. The height of ground covers shall be low enough to allow for adequate levee inspection prior to flood season, based on local conditions. t In most situations, ground cover should be limited to 12 inches or less in height. 2. Thick and/or woody ground covers which may obscure the view of leaks and boils (and make the construction of effective sack rings difficult) will not be permitted. 3. Ground covers or other types of vegetation on/over the levee crown which interfere with maintenance -and inspection activities will not be allowed. 4. Vegetation in areas required for maintenance (which are generally lands within 10 feet of a levee toe) are kept clear for maintenance activities. such as mowing or burning, for inspection purposes, and for emergency flood fighting. Therefore, vegetation on these lands shall be limited to ground covers which are compatible with flood fight and maintenance programs. D. Home Gardens Home gardens are considered to be those which supply the needs of the associated residence. Home gardens are not permitted on the levee slopes, toe, crown, or within the flood control project right-of-way easement. , 2 E. Irrigation 1. Vegetation retained or planted on the levee slopes under a permit may be watered by hand, temporary sprinkling systems, or perm- anently installed irrigation systems. 2. All permanently installed irrigation systems must have an approved permit prior to installation. 3. Any water applied to vegetation on the levee by any means shall be so controlled as to prevent erosion of the levee slopes. 4. No ditches shall be dug in the levee section for the purpose of flowing water or flood irrigating. 5. Excavation into the levee slopes for watering basins around trees will be limited to a maximum depth of 12 inches. 6. Permanently installed irrigation systems may be permitted on the levee slope. 7. Surface drip irrigation systems are considered nonpermanent and may be used on the levee slope. S. pipes supplying water to permanently installed sprinkler heads must be of an approved material, such as galvanized iron, plastic or copper. 9. Permanently installed irrigation pipes may be placed in trenches; however, the pipe shall be buried no deeper than 8 inches into the levee slope. 10. An accessible shutoff or control valve is required in the supply line of all permanently installed irrigation systems. The valve must be located a minimum of 10 feet landward of the levee toe and must be clearly marked with a stake, sign or other means to show its, location to levee maintenance personnel. F. Suitable Plant Species There are many species of plants which can grow in the Delta region and on the project site. A partial list of suitable and unsuitable plant species is attached. This list is intended to be used only as guidelines. Species should be selected which will not impair levee maintenance or flood fight operations. For example, plants armored with large thorns are not allowed. Tree species shall be selected which will not present a wind throw or uprooting hazard due to a typically unsuitable root system or which have a capability 3 of reaching great size and weight leading to unbalance. Because of the potential to attract burrowing rodents, species of trees, .shrubs or ground covers which provide significant food for squirrels are not allowed. Maximum use of native species, instead of exotics, is encouraged. r 4 TABLE 1 PARTIAL LIST OF PLANT SPECIES SUITABLE FOR RESIDENTIAL LEVEES Trees Alder, white Alnus rhombifolia Box Elder Acer negundo California pepper tree (male tree) Schinus molle Carob tree (male tree) Ceratonia siliqua China-berry Melia azedarach Chinese pistache Pistacia chinensis Coast beefwood Casuarina stricta Common catalpa Catalpa bignonioides Crape myrtle Lagerstroemia indica Dogwood, giant Cornus controversa Dogwood, Western Cornus nuttallii . Fremont cottonwood (male tree) Populus fremontii Goldenrain tree . Koeireuteria _2aniculata Hackberry, Chinese Celtis sinenis Hackberry, common Celtis occidentalis Hackberry, European Celtis australis Maidenhair tree (male tree only) Gingko biloba Mayten tree r Maytenus boaria Montezuma cypress Taxodium, mucrontum Oak Quercus spp.* Pagoda tree Sophora Japonica Redbud, western Cercis occidentalis Redbud, eastern Cercis canadensis *spp. = species Suitable Trees (Continued) Sawleaf zelkova Zelkova serrata Silk tree Albizia julibrissin Strawberiy tree Arbutus unedo or Arbutus "marina" Tallow tree Sapium sebiferum Tupelo , - ..,Nyssa sylvatica Suitable Ground Covers Aaron's Beard Alyssum Alyssum spp.* Basket-of-gold Aurinia saxatile Bermuda Grass Cynddon 'dactylon "tifgreen" Cynodon dactylon "coastal" Cynodon dactylon "Tufcote" Blue-eyed grass Sisyrinchium bellum California Poppy Eschscholzia californica Cape weed Arctotheca calendula Creeping wild rye** Elymus triticoides English Ivy, miniature** Hedera helix, hahni Garden lippia Phyla nodiflora Lippia nodiflora Gazania, trailing** Gazania spp.* Green carpet Herniaria glabra Ice Plant, Rosea Drosanthemum floribuhdum Ice Plant, trailing Lam2ranthus, spectabulis Lupine, dwarf Lupinus bicolor Mexican evening primrose** Oenothera beriandieri *spp. = species "These species have specific requirements for being cut back or otherwise maintained on a regular- basis depending—on the species. Suitable Ground Covers (Continued) Palestine orchardgrass Dactylisglomerotoa "Palestine" Salt grass Distichlis spicata Spring Cinquefoil Potentilla tabernaemontanii Stonecrop Sedum spp.* Trailing African daisy Osteospermum fruticosum Verbena** Verbena peruviana Yellow-eyed grass Sisyrinchium californicum r . 'spp. = species — P These species have specific requirements for being cut back or otherwise maintained on a regular basis depending on the species. PARTIAL LIST OF PLANT SPECIES UNSUITABLE FOR LEVEES Trees ,,Acacia, .-.Bailey_*:.,.,. i,- . Acacia baileyana Acacia, kangaroo thorn Acacia armata Almond, edible Prunus dulcis Apple, crabapple, edible Malus spp.* Apricot, edible Prunus armeniaca Ash, Arizona - Fraxinus velutina Ash, flowering Fraxinus ornus Ash, Modesto Fra'"xinum velutina "Modesto" Blue gum Eucalyptus globulus Cedar*** Cedrus spp. * Cherry, edible Prunus avium Chinese jujube Zizyphus_jlljube Chinese wingnut Pterocarya_ stenoptera Citrus, edible Citrus spp.* Coast redwood Sequoia sempervirens Colorado spruce Picea pungens Cypress*** Cupressus s2P-* Date palm Phoenix spp.* Elm Ulmus spp.* Fan palm Washingtonia spp.* Fig, edible Ficus carica Fir*** Abies spp.* Giant sequoia Sequoiadendron giganteum *spp. = species ***Conifers whose normal mature height is 50 feet or less may be considered desirable under maintenance conditions that (1 ) pro tett the tree from drought, and (2) will assure proper pruning of the lower branches. Unsuitable Trees (Continued) Hawthorn Crataegus spp_.* Incense cedar*** - Cal6bbdtus dbcurrens Locust Robinia spp.* Loquat Eriobotrya spp.* Olive Olea" europaea Osage orange Maclura pomifera Peach and nectarine Prunus perica Pecan Carya illinoin-ensis Persimmon Di.6spyros spp.*.' Pine*** Pinus spp. Plum and prune, edible Prunus domestica, salicina Pomegranate, edible Punicagranatum Quince, edible Cydonia oblonga Russian olive Elaegnus *au2ustifolia Salt Cedar Tamarisk gallica Tree of heaven Ailanthus altissima Walnut Juglans spp.* *spp. = species ***Conifers whose normal mature height is 50 feet or less may be considered desirable under maintenance conditions that .- (l) pro tect the tree from drought, and (2) will assure proper pruning of the lower branches. UNSUITABLE GROUND COVERS AND MISCELLANEOUS Bamboo Bambusa spp.* Blackberry/Raspberry Rubus spp.* B rioom'. -Cytisus- spp.-*:- 7Cactus Caictaceae spp.* Century Plant Agave americana False Bamboo, Common Reed Phra2mites communis Freeway Iceplant Carpobrotus spp.* Honeysuckle Lonicera spp.* Horsetail Equisetum- hyemale Ivy, Algerian Hedera canariensis Ivy, Persian •Hedera colchica. Ivy, English Hederal helix except miniature or dwarf varieties Pampas grass - Cortaderia selloana Periwinkle Vinca spp.* Perla Grass Phalaris tuberosa var. hirti2lumis Rose Rosa spp.* *spp. = Species r r 1 Appendix E Geotechnical/Hydrology Information r� r 1 r r - r r Prepared for The Chartered Group, Inc. GEOTECHNICAL INVESTIGATION REPORT PHASE I STUDY PROPOSED BETHEL ISLAND AREA PROJECT EAST CONTRA COSTA COUNTY, CALIFORNIA 1 December 22, 1988 KLEINFEk : ER ---- -- --- in December 22, 1988 File: 11-1956-01 Mrs. Lynn Salomon Jochim The Chartered Group, Inc. 101 Ygnacio Valley Road Suite, 400 Walnut. Creek, CA 94596 SUBJECT: Phase I Geotechnical Investigation Report Proposed Bethel Island Area Project East Contra Costa County, California Dear Mrs. Jochim: Kleinfelder, Inc. is pleased to submit our Phase I Geotechnical Investigation Report for the proposed Bethel Island Area Development. The enclosed report provides a description of the investigation performed and our findings and preliminary design recommendations as they relate to site planning and development. In summary, it is our opinion that the site is suitable for the proposed development provided special provisions for ground modification, and levee design and construction are made. Additional information on our investigative methods, proposed ground modification methods and their relative costs and other geotechnical considerations are contained in the following report. Additional geotechnical investigation and studies will be required for final design of the project. Our specific recommendations for these additional studies is contained in this report. We appreciate the opportunity of providing our services to you on this project and trust this report meets your needs at this time. 1 KLEIIEELDER 6880 troll C(-Wr P.Irk%N\1\. SLHIV 200. Plvasanion. CA y-libb i415 I-UU ' If you have any questions concerning the information presented, please contact this office. Sincerely, KLEINFELDER INC. �aP. Lawrence P. Goldfarb, P.E. Senior Staff Engineer Z- Edward E. Rinne, P.E. , G.E. Principal Terence K. Wang, P.E. , G.E. Office Manager 5 :xp.6l�Oi91 LPG/EER/TKW/j cyl2-10 rglF0rECN11\1j A���� t OF LA0 KIEINFELDER 0880 I:olt Center Parkway. Suite 2500, Pleasanton. C-\ 94566 1415i -18-3-1'00 BETHEL ISLAND AREA EAST CONTRA COSTA COUNTY, CALIFORNIA TABLE OF CONTENTS Page Transmittal letter I. INTRODUCTION. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .1 A. Project Description. . . . . . . . . . . . . . . . . .1 B. Purpose and Scope of Services. . . . . . . . . . . . . . . . . .2 Co Authorization. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 II. GEOLOGY. o . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2 A. Regional. . . . . . . . . . o . o . . o . o . . . . . . . . . . o . . . . . o . . 002 B. Local. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .•. . . .3 C. Faulting andSeismicity. . . . . . . . . . . . . . . . . . . . . . . .5 1. Maximum Ground Control. . . . . . . . . . . . . . . . . . . .9 2. Recent Earthquakes and Observed Damage. . . . 11 III. SOIL— . . . . . . . . . . . . . . . o . . o . o .12 A. Site Description. . . . . . . . . . . . . . . . . . . . . . : . . . . . . .12 B. Field Investigation— . . . . . oo . . . . . . . o . . 00 . . . . . .13 1. Phase I Boring Investigation. . . . . . . . . . . . . . 13 2. Phase I Cone Penetration Testing. . . . . . . . . . 14 3 . Phase I Piezometers. . . . . . . o . . . . . . . o . . . . . . .15 C. Laboratory Testing. . . . . . . . . . : . . . . . . . . . . . . . . . . .15 D. Subsurface Soil Conditions. . . . . . . . . . . . . .15 IV. PHASE I GEOTECHNICAL CONCERNS. . . . . . : : . . . . . . . . . . . . . .18 A. Potential Liquefaction. . . . . . . . . . . . . . . . . . . . .18 1. Evaluation of Liquefaction (Blow Counts) . 19 2. Evaluation of Liquefaction (CPT) . . . . . . . . .20 B. Proposed Levees andLakes . . . . . . . . . . . . . .21 1. Lakes. . . .22 2 . Levees. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .23 _ 3. Borrow for Levees. . . . . . . . . . . . . . .23 C. Site Subsidence and Settlement. . . . . . . . . .24 1. Subsidence. . . . . . . . . . . 000 ... . . . . . . . o . . . . . o .24 2. Settlement. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .26 D. Levee Underseepage. . . . . . . . . . . . . . . . . . . . . . . . .. . . . .26 V. FEASIBILITY OF GEOTECHNICAL MITIGATION TECHNIQUES. .27 A. Reducing Liquefaction Potential. . . . . . . . . . . . . . . .27 1. Remove and Replace. . . . . . . . . . . . . . .28 2. Construction Considerations for Remove and Replace Alternative. . . . . . . . . . . . . . . . . .28 VI. ADDITIONAL SERVICES AND LIMITATIONS. . . . . . . . . . . . . . . .29 A. Additional Services. . . . . . . . . . . . . . . . . . . . . . . . . . .29 B. Limitations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .30 References BETHEL ISLAND AREA EAST CONTRA COSTA COUNTY, CALIFORNIA ' TABLE OF CONTENTS TABLES Table No. 1 - Regional Faulting and Estimated Ground Shaking PLATES Plate 1 - Vicinity Map Plate 2 - Boring Location Map Plate 3 - Geologic Map Plate 4 - Fault Map Plate 5 - Liquefaction Potential Plate 6 - Liquefaction Acceleration Plate 7 - Cone Soil Behavior Chart Plate 8 - Delta Subsidence APPENDIX A iPlate A-1 - Boring Log Legend Plate A-2 through Plate A-29 - Log of Borings B-1 through B-13 Plate A-30 through Plate A-33 - Log of Borings P-1 through P-4 Plate A-34 - Cross Section A-A, 2-D Profile West Side of Site Plate A-35 - Cross Section B-B, 2-D Profile East Side of Site Plate A-36 - Cross Section C-C, 2-D profile Center of Site _ Plate A-37 - 2-D Composite Profile, All Borings APPENDIX B Plate- B-1 - Cone Classification Chart Plate B-2-through B-20 Cone Penetrometer Nos. 1 through 19 E' L ;-LE INFEL� . APPENDIX C Plate C-1 - Grain Size Distribution, Boring B-1 @ 11.0 ft Plate C-2 - Grain Size Distribution, Boring B-1 @ 26.5 ft Plate C-3 - Grain Size Distribution, Boring B-2 @ 21.0 ft Plate C-4 - Grain Size Distribution, Boring B-3 @ 11.5 ft Plate C-5 - Grain Size Distribution, Boring B-3 @ 31.5 ft Plate C-6 - Grain Size Distribution, Boring B-5 @ 33.5 ft Plate C-7 - Grain Size Distribution, Boring B-6 @ 7.5 ft Plate C-8 - Grain Size Distribution, Boring B-7 @ 11.5 ft Plate C-9 - Grain Size Distribution, Boring B-7 @ 16.0 ft Plate C-10 - Grain Size Distribution, Boring B-8 @ 11.0 ft Plate C-11 - Grain Size Distribution, Boring B-9 @ 11.0 ft Plate C-12 - Grain Size Distribution, Boring B-10 @ 3.5 ft Plate C-13 - Grain Size Distribution, Boring B-10 @ 7.0 ft Plate C-14 - Grain Size Distribution, Boring B-12 @ 3.0 ft Plate C-15 - Grain Size Distribution, Boring B-12 @ 7.0 ft Plate C-16 - Grain Size Distribution, Boring B-12 @ 11.5 ft Plate C-17 - Grain Size Distribution, Boring B-13 @ 6.5 ft Plate C-18 - Grain Size Distribution, Boring B-13 @ 21.5 ft APPENDIX D ' METHODS OF MITIGATION OF POTENTIALLY LIQUEFIABLE SOILS 1. Dynamic Deep Compaction 2. Vibrocompaction and Vibroreplacement 3. Soil Mixing 4. Pile Foundations 5. Slurry Cutoff Wall-Permanent Dewatering i 1 1 1 PHASE I GEOTECHNICAL IiiVESTIGATION REPORT BETHEL ISLAND AREA CONTRA COSTA COUNTY, CALIFORNIA I. INTRODUCTION This report presents the results of a Phase I geotechnical investigation for the proposed Bethel Island Area project in East Contra Costa County, California. A vicinity map showing the location of the site is presented on Plate 1. Our investigation has been coordinated with Mrs. Lynn Salomon Jochim of the Chartered Group, Inc. A. Project Description The proposed project consists of developing an area of approximately 681 acres in the Bethel Island Area of East Contra Costa County, California. The project will consist of constructing a ring levee surrounding a development that will be separated into six villages (A-F) . The development will have detached single-family homes, access drives, 23-acres of parkland, a 20-acre commercial and retail center, and an RV storage area. We understand the proposed levee will be approximately 10 to 18 ft in height, 25 to 30 ft wide at its crest, and consist of borrow materials excavated from several proposed lakes for the project. The proposed plans call for the levee alignment to form the perimeter of the six villages as shown on Plate 2. Several walkways and bridges are planned to span the lakes. An executive golf course is planned for the southeastern corner of the property. At this time, the golf course is planned to lie 1 Z5� outside the levee. Additional details of the planned development are not .known to us at this time. B. Purpose and scopeofServices The purpose of this phase I investigation was to explore and evaluate the surface and subsurface soils ; at the site and to provide general recommendations regarding the impact of the geotechnical conditions on the proposed development. Our scope of services for this Phase I study included recommendations and opinions concerning the following: 0 Liquefaction potential, 0 Lake and levee construction, 0 Subsidence and settlement and, 0 Levee underseepage. The scope of services, as outlined in our September 6 and September 14, 1988 proposals, consisted of field explorations, laboratory testing, and preparation of this report. C. Authorization This investigation was authorized by our contracts dated September 9, and September 16, ' 1988, with The Chartered Group, Inc. , signed by Mrs. Lynn Salomon Jochim and Mr. A.J. Salomon, respectively. 11. GEOLOGY A. Regional The site is located within the Great Valley Geomorphic Province, a thick sequence of sedimentary rocks ranging in age from Jurasic 2 sed_mc::z =_' Sequence rests on a basement floor of metamorphic and igneous rocks in the eastern half of the valley. Along the west margin of the Valley, where the very thick Mesozoic strata . are present, basement has not been observed either in outcrop or in well bores. Studies indicate that in the Sacramento-San Joaquin Delta, the sedimentary deposits are thought to be 5 to 6 miles thick (Repenning, 1960, Atwater, 1982) . Structurally, the Great Valley of California, is a large, elongated, northwest trending asymmetric trough. This trough has a long, stable eastern shelf, which is supported by the buried west-dipping Sierran slope, and it has a short western flank that is formed by the steep upturned edges of the basin sediments. The sediments that form the thick valley section were largely derived by erosion of land areas located to the east of the depositional trough. For the major portion of the Jurassic and Cretaceous sediments of the valley, the major sediment source seems most likely to have been the Batholiths of the Klamath Mountains and the Sierra Nevada (Bailey and others, 1964) . During Eocene time, the source rocks are thought to be the highlands on all sides of the basin. B. Local Locally, the site lies near the border of the Great Valley and Coast Range Geomorphic Provinces. The site rests upon deep - sedimentary deposits of unknown thickness. Deposits of marine sediments exceed 13,000 feet in natural gas wells drilled in the nearby Dutch Slough Gas field. These deposits consist of consolidated, regularly bedded, faulted and folded- layers of sandstone, siltstone, shale mudstone, and conglomerate. The structural features in these rocks form traps where natural gas and oil now occur (Draft EIR, Bethel Island Specific Plan, 1988) . 3 During Pleistocene time the delta area is thought to have . undergone several depositional and erosional cycles that were brought about by changes in climate. Sea level changes and glaciation have provided deposition of peat and mud layers and erosion by running water and wind, respectively. Alluvial deposits of silty clay that underlie the Hotchkiss Tract and . Jersey Island at 50 to 90 ft below the present ground surface were probably formed due to a sea level change during a lesser interglacial period about 38,000 to 46, 000 years ago (Atwater, 1982) . Carbon dating has been performed on a soil sample from the site. The location of the sample was approximately 2000 ft north and 600 ft east of the intersection of Bethel Island and �. Cypress Roads. The depth of the sample was 15 ft and its age was found to be 38,100 ± 950 years (Atwater, 1982) . The site geology has been mapped by Nilsen (1975) and by Nilsen and Sims (1975) . The surf icial geology has also' been mapped by Atwater (1982) (see Plate 3) and consists primarily of eolian deposits of wind blown sand. These deposits are of the Upper Modesto Formation and form a large dune field fanning eastward and southeastward from Antioch. The age of the upper Modesto Dune ,Sands lies between 40,000 and 10, 000 years. Locally, these dune sands overlie alluvium of Marsh Creek that in turn overlie San Joaquin River alluvium ranging in age from 38,000 to 46, 000 years. -- The eolian sand is generally fine grained with intermittent silty sand layers. The sand exhibits a moderate amount of cementation in outcrops observed on the western and northeastern portion of the site. They are loose to medium dense in the top 10 to 15 ft and generally dense below this depth. Marsh Creek alluvium deposits consisting of silty clay and clayey silt were encountered in the southwestern and southcentral portions of the 4 site and eneral_y to be thick. Two sets of black and white, stereographic pair, aerial photographs were examined for this investigation. Those were AV-710-20-22, -23 and -24, dated March 22, 1966 and .AV-1700-16-18 and -19 dated May 14, 1979. The photos were examined in an effort to identify the site geologic features pertinent to this study. Surface deposits of sand may be identified on these photos by their light tones. The photos suggest that the areas of overlying sand deposits (which probably Surfaced due to the decomposition and deflation of peat, Atwater, 1982) are readily apparent in the photo pairs. The photos also indicate old man-made drainage features that have apparently been filled. One such feature can be -seen meandering eastward from the Dal Porto Property to near Sandmound Boulevard. C. Faulting and Seismicity The site and the entire San Francisco Bay Area is seismically dominated by the presence of the active San Andreas Fault system. In the theory of plate tectonics, the San Andreas Fault system is the boundary between the northward moving Pacific Plate (west of the fault) and the southward moving North American Plate (east of - the fault) . In the Bay Area, this movement .is distributed across a complex system of strike-slip, right-lateral parallel and subparallel faults which include the San Andreas, Hayward, Ca.laveras, Concord and San Gregorio, among others. A map of the faults showing quaternary displacement is shown on Plate 4. 5 lies in an area near several --faulzZ. faults that have a potential for generating major earthquakes that might affect the site are the San Andreas, Hayward and Calaveras Faults. These active faults J_Ie approximately 52, 34 and 24 miles to the west,, respectively. Other local active faults that may have a potential for affecting the site include: 1) the Concord, located 16 miles to the west, 2) the Greenville, located 17 miles to the west and 3) the Antioch, located 8 miles to the west. Historically - the area has been subject to intense seismic activity. Several historic earthquakes have been associated with the northern segment of the San Andreas Fault. Of these, the April . 18, 1906 San Francisco earthquake, with an estimated Richter magnitude of 8.3, is the most famous. The San Andreas Fault extends roughly northwestward from northern Mexico throughout California, where it can be traced for more than 590 miles from the head of the Gulf of Mexico to Point Arena. The San Andreas Fault has a maximum credible earthquake magnitude of 8.5 (Wesson and others, 1975) . The Hayward Fault trace lies approximately 34 miles west of the site and extends northwestward from the cities of Warm Springs on the south to San Pablo on the north. There is abundant evidence of tectonic slippage or a seismic creep, along the Hayward Fault, where movement. of 0.2 to 0.76 cm/year has been measured (Herd, 1978) . Based on the postulated maximum length. of rupture, an upper bound magnitude of 7.5 is generally used in seismic design for this fault. The northern portion of the Calaveras, Fault lies approximately 24 miles to the west of the site where it trends subparallel to the San Andreas Fault. The Calaveras Fault is thought to be the cause of the July 2, 1861 earthquake which reportedly generated 6 intensity snaking _.. :::e San Ramon Valley. _.uoss s-;nS of activity along the Calaveras Fault are confirmed by the Coyote Creek earthquake of August 6, 1979 and through conspicuous seismic creep, which ranges from 0.2 to 0.7 cm/year (Herd, 1978) along certain segments of the fault. The Concord Fault extends about 15 miles south of Suisan Bay. It is a predominantly right-lateral strike-slip fault which has a recent history of seismic activity, and has clearly offset Holocene land deposits (Oakeshott, 1980) . The Concord Fault expresses itself north of Suisan Bay as the Green Valley Fault, although the two faults may not be related. The Concord Fault is thought by several seismologists to have an upper bound magnitude of 6.25. 1 In the vicinity of the site the active Antioch Fault has been described by Berke and Helley (1973) as displaying active creep within Antioch. A study prepared by the California Department of Water Resources (1978) , concluded that the Antioch Fault was a nearly vertical to steeply westward-dipping fault that possibly shows right-lateral strike-slip movement. Earth Science Associates (1982) concluded that the age of the last offset (on the Antioch Fault) must be Post-Pliocene and is most likely Holocene. Other investigators have also found evidence of Holocene movement on the Antioch Fault. Historically, the Antioch Fault or an extension of the Antioch - Fault to the north was thought to have been a likely source for some small to moderate earthquakes that occurred in 1866 and for the Collinsville earthquake of May 19, 1889, which was apparently felt throughout most of Central California (U.S. Department of Commerce, 1973) . An earthquake swarm which occurred southwest of Antioch was recorded in 1965, and appeared to be centered about 9 miles west of the site. The maximum credible earthquake for the 7 ;':.ntioch Fault is thought to be abouz. 6. 6, and others (1975) . The inferred trace of. the Midland Fault is mapped as lying approximately 0.5 miles to the east of the site. The northern section of the Midland Fault was thought to be the source of the April 19 and April 21, 1892 Vacaville, and Winters earthquakes which caused several stone and brick buildings to fall. The shock was apparently felt as far east as Reno, Nevada.. The Midland Fault is not shown as an active fault on the Fault Map of California (Jennings, 1975) or on the regional Fault Map (Helley and Herd, 1977) . Further, recent studies by Bolt (1985). have indicated that the Midland Fault is not a likely source of significant earthquakes: There is no surface expression of this fault system as one might expect if continuous major displacements (largely dip-slip) had- occurred during Quaternary time. Further, there is little doubt that the dominant tectonic forces now deforming the whole region about the site are large-scale horizontal right-lateral shears related to straining of the San Andreas - fault systems. Thirdly, there is no evidence from the seismicity of the region of significant earthquake activity associated with the Stockton or Midland faults. (From Draft EIR, Bethel Island Area Specific- Plan, 1988.) Based on the seismic record, it does not appear likely that strong ground motion will be generated by this fault. A list of active faults along with their maximum credible and probable earthquakes and expected range of Peak Horizontal Accelerations on Rock is shown in Table No. 1. Please note that the maximum credible earthquake is the largest seismic event that appears capable of occurring along a recognized fault or seismic 8 _- - --Under kno►an or Inferred s=_smo--acItor:_c The /maximum credible acceleration represents an upper bound estimate of the ground shaking that could conceivably affect the S site as a result of the postulated occurrence of the maximum credible earthquake. It should be noted that the maximum credible earthquake implies a rare but physically possible earthquake occurrence. While such a level of motion is normally considered for design for large safety-related structures . such as nuclear power plants and . hospitals, it normally is not used in ordinary residential or commercial structures due to its low probability relative to other natural or man-made hazards. The maximum credible acceleration depends on numerous factors such as source and site conditions, transmission path characteristics, and to a greater extent, the fault to site distance and magnitude of the event. Several attenuation equations have been developed to evaluate the ground accelerations over the past 10 to 15 years. The values shown in Table 1 are derived from relationships formulated by Joyner and Boore (1981) , Campbell (1981) , Seed & Idriss (1982) and Sedigh (1983) . Y an s not crossed b mapped active faults; The site proper i Y PP _ however, it will likely be subjected to a high degree of ground shaking from earthquakes generated on the Antioch, Greenville, as - well as other active faults in the Bay Area, 1. Maximum Ground Motion A probabilistic study was performed to provide information related to the return periods of earthquakes. Probabilistic analyses are considered reasonable since they are concerned 9 _imarily v:_zh -ea==::=r = _e-�u . Pe=yods that ;:o not , significantly with the length of the earthquake record. Recent statistical studies have proven the applicability of probabilistic earthquake studies. The analytical procedures used in this study take into . account the assumption that the seismic record surrounding the site is sufficient and that there is a logarithmic relationship between the acceleration, earthquake magnitude and distance from the epicenter to the site. Calculations are directed towards evaluating the expected annual rates of occurrence of peak horizontal ground accelerations due to the earthquake events accounted for in the record in the geographical area. For this study, approximately 1, 000 earthquakes generated on the San Andreas, Hayward, Calaveras, Greenville, Green Valley, Rogers Creek, Concord, Antioch and Midland Faults were used. These statistically documented events are used to postulate future occurrences. The attenuation relations used in the probabilistic analysis were from McGuire (1978) and Joyner and Boore (1981) . The results of the analysis indicate that there is a 50 percent probability that a peak horizontal ground acceleration of 0. 18 - 0.20g will be exceeded at the subject site over a 50 .year exposure. The results also indicate that there is a 90 percent probability of non-exceedance of a 0.30g acceleration occurring at the subject site over a 50 year. exposure. Please note that the record used to evaluate these probabilities did not include. - the 1868 Hayward earthquake, the 1861 San Ramon Valley earthquake, and perhaps most importantly the 1889 Collinsville earthquake. Use of these earthquakes would likely increase the above accelerations. Further, these accelerations are not site- soil specific and do not take into account potential amplification or damping that may occur due to the deep sediments in the Delta area. 10 2. Recent Earthauakes and Observed Damage Perhaps the most important aspect in investigating the seismicity of the Delta region deals with reviewing the effects of past earthquakes. Until recently -the earthquake safety of the Delta Region was largely ignored. This was due primarily to the fact that there were no reported levee failures or levee damage that could be directly linked to earthquake activity. Although there was no reported levee damage during the 1906 earthquake, several bridges sank in the Delta area. The Santa Fe Railroad bridge at Middle River sank 3 ft and twisted out of line t (Salinas Daily Index, 1906) . According to the San Francisco ` Chronicle, the bed of the Molkelumne River near Lodi sank 12 ft. These embankments were similar in composition to the present day levees. Recently, levee damage was reported on Webb Tract after the May 2, 1983 Coalinga earthquake. Fourteen other reports of rearthquake related damage have been linked to five separate events with earthquake epicenters ranging from 15 to 150 miles from the area. Damage was reported on the Mandeville Tract minutes after the Coyote Lake Earthquake of August 6, 1979. A 250 ft rotational slip-out was observed on Bacon Tract by the Department of Water Resources (DWR) as possibly being earthquake related damage due to the January 24, 1980 - Livermore earthquake. A 200 ft landslide slip-out dropped 6 inches on the Empire Tract as a result of the 1980 Livermore earthquake. Damage was observed on the Webb and Venice Tracts due to earthquakes generated by the .Coalinga, Pittsburg and Morgan Hill earthquakes. Most of the levees that were damaged due to the earthquakes 11 contained large amcu:.-:�_ of sand wit__ general__ (Finch, 1985) . Although there has been several accounts of varying amounts of damage to Delta levees, it appears that there were no recorded failures. Those damaged appeared to have . been repaired and it appeared that the- Delta Levees as a whole were not largely impaired. Further, the literature suggested that those islands where levee damage did occur generally have soft deposits of peat and consisted of loose sand with little clay content. These conditions are not similar to those found on the Hotchkiss Tract. A review of the literature following the historic ground shaking events indicates that ground failures are common but occur in close spatial relation (approximately 10 kilometers) to the i ruptured fault -trace. III. SOIL A. Site Description The project has an approximate area of 681 acres, and is located in the Bethel Island Area of East Contra Costa County, California. The site is located .on 'a portion of the Hotchkiss Tract. ' The site lies to the south of Bethel Island proper, and is bounded by Sandmound Boulevard to the north and east. The .- southern boundary of the site lies approximately 2 ,800 ft to the south of Cypress Road. A site vicinity map is shown on Plate 1. The site is generally flat ranging in elevation from approximately -5 ft to -8 ft, with scattered mounds reaching an elevation of 10 ft. The north central portion of the site is covered by areas of fine-grained,wind-blown sands that exhibit 12 slight to modern-�e cementation. The site used predcr,._:an as rangeland and is covered by short and tall grass. The site is 1 divided by fences and certain areas were in the process of being irrigated during our field visit. The southern portion of the site lies primarily on the lands of Leo Mantelli. These areas have been recently plowed and disced. A high voltage powerline crosses the southwestern corner of the site on the Dal Porto property. The interior of the site contains several shallow drainage canals used for irrigation. B. Field Investigation 1. Phase I Boring Investigation Our phase I boring exploration started on September 16, 1988 and was completed on September 22, 1988. It consisted of drilling and sampling 13 test borings at the approximate -locations shown on the Boring Location Map, Plate 2. The borings were drilled with a Failing 1500 ,truck-mounted rig equipped with wet-rotary drilling equipment. All borings were drilled in the dry to a depth of three feet, prior to placement of casing and use of wet rotary techniques. All test borings were logged by our field engineer. The borings were advanced at wide spacings primarily along the proposed levee alignment to a maximum depth of 128.5 ft Materials encountered in each soil boring were visually classified in the field and a continuous log was recorded. Visual classifications were made in accordance with the Boring Log Legend presented on Plate A-1 of Appendix A. Soil samples were obtained by driving a 2-in.-ID, 2-1/2-in.-OD modified California Sampler, containing thin brass liners, into 13 the bo atom of the boring. The number c- :.lows required to driv , the last 12 in. of an 18 in. drive with a 140 lb. donut hammer dropping 30 in. is recorded as the Penetration Resistance (Blows/ft) on the Boring Logs. When the sampler was withdrawn from the boring, the brass liners containing the samples were removed, examined for logging, labeled and sealed to preserve the natural moisture content for laboratory testing. Granular samples were typically obtained with a 1-3/8-in.-ID, 2-in.-OD Standard Penetration Sampler. Undisturbed samples were typically - obtained by pushing a 3-in. Shelby Tube or by using an Osterberg Sampler. 2 . Phase I Cone Penetration Testing The phase I cone penetrometer program started on October 5, 1988 and was completed on November 9, 1988 . The program consisted of performing a total of 19 soundings at the approximate locations shown on the Boring Location Map, Plate 2. Soundings were made along the levee alignment and in the lake areas in an attempt to "fill-in" large spaces between borings. . A Hogentogler Piezocone �. having a tip area of 10 cm.2 and an apex angle of 60 degrees was used in this program. The cone contains a friction sleeve on its side having a standard area of 150 cm 2. The cone penetrometer has separate load cells that record the tip resistance (Qc) and the side friction (Fs) as the cone is pushed through the soil at _ a rate of approximately 2 cm/sec. A continuous log of (Qc) , (Fs) and pore pressure (Pw) were recorded. Soil classifications were interpreted using the Simplified Classification Chart for the . Standard Electric Friction Cone shown on Plate B-1 of Appendix B. Continuous logs of the cone penetrometer soundings are shown -on Plates B-2 through B-20. The cone penetrometer was advanced to a maximum depth of 28 .5 ft. The underlying very dense sands encountered at depths ranging 14 f=:,::: weeper =rom to 30 ft prevented the cone penetrometer investigation. 3 . Phase I Piezometers Four piezometers were installed at the site on September 22, 1988. The piezometer locations are shown on the Boring Location Map, Plate 2. The piezometers are 15 ft in depth and consist of a 10 ft section of 0.20-in. , slotted, PVC Schedule 40 pipe, and a 5 ft section of a PVC, Schedule 40 riser. The piezometers were backfilled with 12/12 sand in the slotted portion, followed by 3/8" diameter bentonite pellets and sealed with a cement grout. The logs of the piezometers are presented on Plates A-30 through A-33 of Appendix A. C. Laboratory Testing i The laboratory testing program was formulated with emphasis on the evaluation of the gradation and strength characteristics of the subsurface soils. The laboratory testing program consisted of unit weight and moisture content, Atterberg Limits, unconfined compression, and percent passing the #4 and #200 sieves. Most of the laboratory test results are presented on the individual logs of the borings. Graphic presentations of the gradation analyses performed are shown on Plates C-1 through C-18 of .Appendix C. D. Subsurface Conditions The soil conditions at the site are dominated by loose to dense sands and silty sands to a depth of 120 ft. Sands in the upper 10 to 15 ft are generally loose to medium dense and dense below 15 his . ez)-ch. =_Vlll azou.. __-40 :.o El 60, a very sziff -o h aiaa layer of silty clay was encountered in most borings. This layer appears to be continuous across the site; however, the thickness and presence of this layer should be further classified by additional exploration for groundwater hydrology and cut-off purposes. The near surface soils consist of a thin topsoil layer underlain by a 1 to 2 ft thick layer of sandy clay and clayey sand. A thicker sandy and silty clay layer was encountered in the borings and cone penetrometer soundings across the center of the Mantelli property, south of the proposed Cypress Road Extension (see B-5, B-7,B-8, B-9, CPT-17, CPT-18 and CPT-19) . In this area the sandy and silty clay layer appears to be about 5 to 9 ft thick. Some organic material was observed in Boring B-5. According to our cone penetrometer soundings, some organic material (peat) may be present in the area where CPT-4, 9, 13 and 19 are located. The interpretation of organic material was made from 'abnormally high friction ratios recorded at these locations. The peat appears to be limited in thickness and generally occurs in the top 5 ft. Generally, clays across the site are of low to medium plasticity and are stiff to very stiff. The findings in the borings and cone penetrometer soundings are in general accordance with the surficial mapping by Nilsenland, Nilsen, and Sims (1975) and Atwater (1982) in which these soils are referred to as Alluvium of Marsh Creek. Underlying the sandy and silty clay layer are fine grained, loose to medium dense sands and silty sands. Underlying areas where the Marsh Creek Alluvium is found , (Borings B-5, B-7, B-8 and B- 9) the sands are generally medium dense to dense. In; the other nine borings, these sands are loose to medium dense to a depth of 15 to 20 ft and dense to very dense below 20 ft of depth.. 16 A light brown sandy and _gay lave_ was encountered at a depth of 48 to 56 ft below the existing ground surface in most borings. An exception to this was observed in Boring B-13, where this clay layer was encountered at a depth of 36 ft. The clay layer is very stiff to hard and ranges from 8 to 20 ft in thickness. Underlying this clay layer are dense sands and silty sands containing thin intermittent hard silt and clay layers to 128.5 ft, as observed in Boring B-1. Groundwater levels were read for the first time on September 29 and October 5, 1988. They were read a second time on November 9, 1988. The watertable elevations observed and the dates that they were measured are as follows: Piezometer Approximate Static Water Elevation (in feet) P-1 (9/29/88) -10.5 111- P '- (11/9/88) -11.5 P-2 (9/29/88 -4.8 P-2 (11/9/88) -5.2 P-3 (9/29/88) -4.6 P-3 (11/9/88) -5.0 P-4 (10/5/88) -6.8 P-4 (11/9/88) -7.0 The above is a general discussion of the soil and groundwater conditions encountered in the 13 borings, 19 cone penetrometer - soundings and 4 piezometers at the site. Two-dimensional profiles of select borings are graphically presented on Plates A-34 through A-38 of Appendix A. A fold-out soil legend for the two-dimensional profiles is on Plate A-39. For a more detailed description of the Phase I boring logs and cone penetration soundings see Appendices A and B, respectively. 17 The soils bor=n7s and cone penetrome=-E_ -- w=re widely spaced locations for this Phase I study. Soil and groundwater conditions can be expected to deviate from these conditions encountered at the piezometer locations. Additional monitoring of these piezometers should be performed to help evaluate these potential deviations. IV. PHASE I GEOTECHNICAL CONCERNS �. Based upon data collected during this investigation, we note. the following four geotechnical concerns relating to the feasibility of the project. They are: A. Potential liquefaction in the near surface sand layers, B. Lakes and levees, C. Subsidence and Settlement, and �. D. Levee Underseepage. A combination of research and preliminary analyses were performed for each of the above considerations. The results of our findings and analyses combined with our experience in the area were used to provide recommendations for mitigation of these concerns. A. Potential Liquefaction -- Liquefaction includes all phenomena - involving excessive deformations or movements as a result of transient or repeated disturbance of saturated cohesionless soils. The liquefaction potential was assessed based on the soil boring blowcounts, the cone penetrometer resistances and friction ratios, correlations between the CPT and SPT data, the results of the laboratory tests and the site seismicity, and historical data. 18 - i• -- - - --- ---- - - - - - •Yr The results of the Phase I field investigation boring and cone Ipenetrometer data indicate that there are areas that are considered to be potentially liquefiable. There is insufficient data at this time, to indicate whether these areas are localized or whether they occur over a larger area. For development purposes it should be pointed out that areas of the site appear to be potentially liquefiable. The location and Ok severity of the liquefiable areas can only be further additional borings and laboratory characterized by performing g gradation analyses. Details of the analyses and results of the boring logs and cone penetrometer tests for the Phase I investigation are contained in the following two sections. 1. Evaluation of liquefaction using Boring Blow Count Data The potential for liquefaction of the soils encountered in the borings was evaluated using the procedures established by Seed and Idriss 1982 and Seed et al. (1984) . The number of blows per ft recorded in our field boring program and the results of laboratory gradation analyses were used to evaluate this potential. Soil borings exhibiting low soil blow counts were evaluated. Penetration resistance values (blow counts) were standardized with respect to overburden, fines content and reduced hammer energy (donut hammer) . The standardized - blow counts were then used in the analysis. Based on the blow . count data measured during our field investigation and the results of our laboratory tests, it appears that a magnitude 6.75 earthquake creating peak ground acceleration of 0.2g or greater would probably result in 19 liquefaction of the :fear-surface sands and si_ty sands over Mc sem of the site. Plate 5 shows a chart for the evaluation of potential liquefaction for sands for earthquakes of different magnitudes. Lines showing the standardized blow count for observed liquefaction for a ground acceleration of 0.2 and 0.3g are shown for a magnitude 6.0 and 6..75 earthquake. The blow counts presented on the plate are considered a good approximation of the minimum blow count to resist liquefaction. Plate 6 shows the estimated peak horizontal ground accelerations which will induce liquefaction at select boring and CPT locations. Based on a 0.2g acceleration at the site, soils encountered in Borings B-1, B-2, B-10 and B-12 would probably experience liquefaction. Boring and cone penetrometer locations not having numbers are not considered to have a high potential for liquefaction. In .summary, it is our opinion that portions of the proposed development would be expected to experience liquefaction should a ground acceleration of 0.2g or greater occur at the site. 2. Evaluation of Liquefaction Using CPT data The potential for liquefaction at the site was also evaluated using the continuous Cone Penetrometer records. Correlations between cone penetration resistance (CPT) and standard 'r penetration resistance (SPT) were made using the chart shown on Plate 7. Typical mean grain sizes were used from the grading analyses performed on the near-surface soils and are graphically presented on the Plates in Appendix C. 20 La Based on the CPT data, the near sur=-ace soils at CPT-2, 3 , 4 , 51 7, 9, 11, 14,' 15 and 16 may be expected to liquefy if a peak ground acceleration of 0.2 g was experienced at the site. Plate 8 shows a proposed zone of potentially liquefiable soils utilizing the cone bearing and friction ratio of the soils. Soils that lie in Zone A are considered to be potentially liquefiable. There is reasonably good agreement between this and the Seed method of evaluating the liquefaction potential on this project. Liquefaction of the near-surface soils could cause severe levee damage and damage to structures and utilities. Some spreading of the loose soils adjacent to the Sandmound Slough could occur, l causing a block of soil to flow toward the Slough. A resultant graben could form in the vicinity of the new levee. Also, differential compaction of the underlying loose sands could occur causing differential settlements across structures. Due to the relatively thin non-liquefiable clay layer overlying the liquefiable sand and silty sand layers at the site, differential settlements would tend to manifest itself at the ground surface. Recommendations for mitigation of these settlements are given later in this report. B. Levee and Lakes Design plans for the proposed lakes and levees at the project are �. still in the preliminary stage. We understand that preliminary design plans call for a ring levee to be constructed about the inhabited portion of the site. Several large interior connected lakes are also planned. Soil material from the excavated lake regions are planned for use in the construction of the levee. 21 We unde=s=and that the levee will be about 25 to 30 ___ . at- the tthe top with 3 : 1 horizontal to vertical side slopes. At this time there is a proposed commercial area that will rest on top of the levee near the intersection of Cypress and Bethel Island Roads. Here the levee may be up to 400 ft wide. To our knowledge no other structures except for a bicycle or walking path are planned to be placed on top of the levee. We understand that the depth and dimension of the lakes will be based on the amount of soil material needed to construct the levee. These quantities are not known to us at this time. 1. Lakes It is assumed that the lakes will be constructed with . a 1 ft high freeboard, with slopes of approximately 5 to 1 horizontal to vertical, to a depth of 3 to 4 ft or about 20 ft from the shore. From this point the slope and total depth of the lakes have not yet been determined. Based on the boring and cone penetration. logs the lakes will primarily be excavated through fine grained, poorly graded, silty sands and sands having generally 5 to 15 percent fines. The near surface sands are loose to medium dense to a depth of 15 ft. For this reason the lake slopes should be planned to be as flat as possible and be lined with a shotcrete or cement slurry coating to prevent disturbance. We understand from our conversations with Mr. Harlen Glenn of Harlen Glenn Consultants that the lake slopes will be grouted or stabilized up to 20 ft from the shore. Q The depths of the lakes should be kept to a minimum to increase the stability of the excavated sands and to reduce the risk of lateral spreading of the sands into the deeper .portions of the excavation. Further, special provisions should be made where 22 a :e =ve� `:.a525 a=c _ _armed. Due to the excavat-L added potential for piping or seepage forces may be created. Steeper slopes will tend to cause higher seepage gradients. Additional investigation and stability analysis should be performed to evaluate the effects of the lake and levee slopes, the watertable level and the minimum distance between the lakes and the levees. This should be performed once design lake levels and grading plans are more complete. 2. Levees In 'the 13 borings and 19 cone penetrometers performed for Phase I of our investigation, we encountered organic material, generally a peaty sand, in B-5 and in CPT-4, 9, 13 and 19. Generally the peaty soils were encountered within 5 ft of the existing ground surface. Some excavation and replacement with suitable materials may be needed in soft or potentially liquefiable areas. It is our opinion that the subsurface soils should provide P adequate static stability. However, it is our opinion that ground modification will be necessary to provide adequate stability under dynamic conditions. Modification measures are proposed in later sections of this report. 3 . Borrow for Levees Based on the results of the borings and cone penetration tests it appears that the on-site soils should be suitable for the levee construction. Our borings indicate a strong potential for a clay and silt source South of Cypress Road on the Dal Porto and Mantelli properties. Cone penetration tests performed in the southcentral and southeastern portion of the Mantelli property, and borings in the southwestern portion of the Del Porto property 23 -_cate 5 to _ .t of s=_=`_' c=__ _-._ .._ayey ..__.. �:_th sand lie J . this . area. An estimation of the quantity of this material available is beyond the scope of our work. We recommend that several backhoe test pits be excavated to supplement the cone penetrometer soundings and further evaluate the extent and thickness of this material. It is our opinion that the fines in the southern portion of the site can be excavated and used for levee construction in proportion with the sand materials. The exact use of the fines and therocess of construction will largely be P g y controlled by the particular design of the levee, which should be further investigated in Phase II of the geotechnical engineering for ��. this project. _ C. Site Subsidence and Settlement 1. Subsidence Subsidence is the gradual settling or sinking of an area with little or . no horizontal_ motion. There are several causes of i subsidence including natural processes such as oxidation, solution, thawing, drying, wetting, subsurface compaction, tectonic downwarping or a combination of these factors. Man-made subsidence includes removal of solids, liquids and gas from beneath the ground surface. Subsidence caused by these processes may be rapid and may have significant impact on the development site. Oxidation of clay-rich peats, the withdrawal �- of . groundwater and the extraction of natural gas trapped in tertiary rock units are primary reasons for the large amount of subsidence . in the Delta region in the last 60 years.. The proportion of subsidence due to each of these causes is not known. However, peat oxidation is thought to be proportionately 24 high on some of t:e Delta Tract-S. Three ac=s =_ __.:d adj ac=_ -- to Contra Costa County (Bacon Island, Mildred Island and Roberts Island) which were originally at or slightly above sea level, are now at .10 to 11 ft below sea level. Between 1922 and 1946, these three islands have subsided at rates of 0.2 and 0.3 ft/yr (Weir, 1950) . Plate 8 shows the maximum amount of subsidence on individual islands in the Delta Region. According to the Delta Subsidence Investigation, Progress Report 1986, subsidence may be as high as 0.25 ft/yr in peat areas and as low as 0.007 ft/yr in areas with little to no organic soils. Based on the relative subsidence shown in Plate 8 and the lack of thick peat deposits on the site, we anticipate that the subsidence at the site should be in the lower portion of this range. However, deep- subsidence could still continue depending on the production of the area's gas wells. A subsidence measuring program was spearheaded by the Department of Water Resources primarily to study and attempt to differentiate the effects of gas extraction and near-surface organic oxidation. We understand that the compaction monitors ' for the study have been in place for only a couple of months and that it will be several years before sufficient,_data will be available (Personal Communication with Mr.. Todd Nelson, Contra Costa County Planning Geologist, 1988) . It may be prudent to assume that the area will continue to subside over the life of ' the project and special provisions should be made to accommodate this subsidence. The provisions should include an allowance of increased freeboard on the levees and/or a monitoring system to provide site-specific information on levee and structure subsidence. 25 l LL 2 . Settlement Based on the results of our boring logs, the subsurface granular soils at the site are medium dense to dense below a depth of 15 ft. Provided special provisions are 'made to densify the near surface sands, settlements due to the levee or single-family structures, should be similar to what is normally expected on well consolidated alluvial sites. Most settlements should be elastic in nature and should occur rapidly upon fill or structure placement. The southwest portion of the development appears to contain a silty and sandy clay layer that generally ranges in thickness from 2 to 5 ft. The clay was encountered in Borings B-4, B-5�, B- 6 and CPT-10 at a depth of 21 to 26 ft below the existing ground surface. This clay layer appears to be very stiff and confined to the southern portion of the proposed Commercial site and Village F. A surface clay layer approximately i2 ft thick was encountered in CPT-13 in the -southeast corner of Village F. Based on the cone data, settlements should be small.. A settlement analysis should be performed in these areas during Phase II of this study. D. ' Levee Underseepage Considering the preliminary development plans and due to the nature and relative elevation of the site to the Sandmound Slough, hydrologic . impacts due to changes 'in static groundwater level, lake level, slough level and flooding on adjacent Tracts should be investigated. Based on our experience in the area and discussions with the farmers in the site vicinity, seepage and boiling has not appeared to be a major problem. Groundwater level readings 26 indicate that there is 4 � head loss of up to i ft� from -he Sandmound Slough to Piezometer P-4, located in the east-portion of the site. The reason for this head loss is not known, however it may stem fr y , om a combination of natural thick peat layers adjacent to the levee on Sandmound Boulevard and silt deposits in the Slough. Considerable dewatering will be likely to allow construction in the dry. Because of preponderance of sand at 'the site, the toe drains can be planned ahead of time to "double up" for both temporary and permanent dewatering. Further evaluation is needed in the Design Phase (Phase II) to assess levee underseepage. V. Feasibility of Geotechnical Mitigation Techniques The primary geotechnical considerations regarding the proposed development are: A. Reducing the potential for liquefaction and, B. Controlling levee underseepage. Possible mitigation schemes are presented in the following paragraphs. A. Reducing Liquefaction Potential Several methods are available for treating the near-surface loose _ to medium dense sands and silty sands. Generally, in the Delta area liquefaction of near-surface deposits has been mitigated by removing the liquefiable material and recompacting it by conventional means. This method is described in the following paragraphs. Additional methods that were evaluated for the purpose of reducing the potential for site livefaction are as contained in Appendix D. For the purposes of this study, the 27 Remove and Replace option is discuss-:;. --,al ow. Other site improvement techniques, along with the Remove and Replace option, described in Appendix D will be evaluated in the Phase II study. 1. Remove and Replace Using Temporary Dewaterinct The liquefaction potential in the top 10 to 15 - ft of soil can be mitigated by removing the soil and recompacting. This has been achieved on other projects where high water was a problem by excavating .deep. trenches and dewatering. The subsurface silty sands and sands are anticipated to. have a relatively high permeability. Advantages of this method are (1) no potential damaging effect on adjacent properties from vibration, (2) soil densification and lake construction can be performed in the dry and, (3) the construction can be staged, with the exception of levee construction 4 its relatively ow cos nstru i n and ( ) i y l t with respect to other non-conventional improvement methods.. The cost of this method is dependent to a large extent on the cost ' of dewatering g and the water content and workability of the soil. 2. Construction Considerations for Remove and Replace Alternative The top 2 to 3 ft of clayey soil can be removed and laid out to dry in an adjacent village. The underlying sands may be removed from one area and immediately replaced as construction progresses. Historically, levees and lakes in the valley areas have been constructed using native soils. If clays are desired to be mixed with native sands, then the surficial clays could be stockpiled for mixing. r` Provided the excavated material can be readily removed, placed in a staging area, replaced and recompacted, we were informed that 28 L -zhe es'Z.-n.ated cost would be about $1.201CY. Or abou.z 60/sf for a depth of 15 ft. Temporary dewatering costs are not included. For the Discovery Bay project, the approximate cost for grading, including dewatering, was $1.00/c.y. For preliminary cost purposes assume that the top 13 ft of soil would have to be removed and replaced in the non-lake portion of the villages. VI. ADDITIONAL SERVICES AND LIMITATIONS A. Additional Services Based on the findings of this Phase I geotechnical Study we recommend that the Phase II Geotechnical Investigation include but not necessarily be limited to the following: 1. Additional borings and/or cone penetration testing should be performed to further identify the soil conditions at the site. In particular, a combination of additional borings and/or -cone penetration tests should be performed. in an attempt to identify specific areas where liquefaction mitigation may be necessary. 2. Several tests pits should be excavated in the Mantelli property (southern portion of the site) to evaluate the quantity and quality of the clay materials in this area. Specifically, the material should be examined for peat or organic content, hydraulic conductivity and moisture content for use in levees, landslide seepage berms and as a lake liner. 3 . Additional investigation concerning the groundwater hydrology should be performed to obtain a more approximate estimate of the permeability of the 29 ___aar ing s sand and sand soils and Sze ydrolo;y of the Sandmound Slough area. .o 4.. It is our opinion that the Phase II Geotechnical Investigation should include but not necessarily be limited to be (1) additional borings for evaluation of liquefaction potential, (2) specifications for design ' of levees, (3) static and dynamic slope stability �. analyses for levees, (3) application for FEMA approval of levees and (4) settlement analysis for levees. 5. Specific recommendations for (1) site improvement, (2) lake excavation and construction, and (3) building foundations, pavements, and retaining 'structures, should be developed in a separate report from that of the levees. The Phase IP round improvement options' should also be g evaluated by the design team and by Kleinfelder mutually to obtain a. workable, feasible and viable solution as a part of this separate report. B. Limitations The services provided under this contract as described in this report include professional opinions and judgements based on the data collected. These services have been performed according to generally accepted geotechnical engineering practices. that exist in The San Francisco Bay Area at the time the report was written. No other warranty is expressed or implied. This report is issued with the understanding that the owner chooses the risk he wishes to bear by the expenditures. involved with the construction alternatives and scheduling that is chosen. 30 i The conclusions and recommendations of this report are for the Bethel Island Area project, as described in the text of this report.. The conclusions and recommendations in this report are invalid if: 0 the assumed preliminary design plans change, 0 the levees, lakes and/or structures are relocated, 0 the report is used for adjacent or other property., 0 the Additional Services section of this report is not followed, 0 if changes of grades and/or groundwater occur between the issuance of this report and construction, or 0 any other change is implemented which materially alters the project from that proposed at the time this report is prepared. The conclusions and recommendations presented in 'thi.s report are preliminary and are based on a limited amount of information obtained from a Phase I Investigation which included the following: 0 13 borings, 19 Cone Penetrometer Tests (CPI's) , and 4 Piezometers, 0 the observations of our geotechnical engineer, 0 the results of laboratory tests, 0 verbal communication with contractors and, o our experience in the area. The boring logs, Cone Penetrometer Tests and Piezometers do not provide a warranty as to the conditions which may exist at the entire site. The extent and nature of subsurface soil and groundwater variations may not become evident until construction begins. It is possible that variations in soil conditions. 31 between borings, cP-. 1s. and Piezometers could' ex -Ween or beyond the points of exploration or that groundwater elevations may change, both of which may require additional studies, consultation and possible design revisions. If conditions are encountered during the Phase II Geotechnical Investigation which differ from those described in this report, the feasibility of the - above outlined options could change accordingly. As a result, revisions to these recommendations may be necessary. It is the client's responsibility to see that all parties to the project including the designer, contractor, subcontractors, etc.- ,, are made aware of this report in its entirety including the Additional Services and Limitations sections. - . 1 32 TABLE 1 REGIONAL FAULTING AND ESTIMATED GROUND SHARING Approx. Max. Cred. Max. Prob. Peak Horiz. Fault Dist. (mi) Earthauake Earthquake Bedrock Accel.** San Andreas 52 8.5 8.25 0. 05 - 0. 15 Hayward 34 7.25 6.75 0. 05 - 0.20 Calaveras 24 7.25 6.5 0.05 - 0.30 �1 Concord 16 6.25 5.5 0.10 - 0.30 Greenville 16 6.25 5.5 0. 11 - 0.25 Antioch 8 6.6 5.5 0.15 - 0.40 * From Revisions of Portions of Contra Costa County Seismic Safety Element by Woodward-Clyde Consultants, January 1986 ** Estimates based on relationships by Seed and Idriss (1982) , Joyner and Boore (1981) , Campbell (1981) and Sadigh (1983) . ,1 REFERENCES Army Corp of Engineers, 1978; Design and Construction of Levees, Department of the Army, engineer Manual EM 1110-2-1913 . Atwater, B. F. , 1982; Geologic Maps of the Sacramento - San Joaquin Delta, California Department of the Interior, USGS Map MF-1401. Bailey, E. H. , Irwin, W. O. , and Jones, D. L. , 1964; "Franciscan and Related Rocks and Their Significance in the Geology of Western California; CDMG Bull. 183. Burke, D. B. and Helley, E. J. , 1973 ; "Map Showing Evidence for Recent Fault Activity in the Vicinity of Antioch, Contra Costa County, California, USGS Map MF-533. California Department of Water Resources, 1978; Preliminary Report - Fault and Seismicity at Los Vequeros Dam Site. California Department of Water Resources, 1980; Seismicity Hazards in the Sacramento - San Joaquin Delta. Campbell, K. W. , 1981; Probabilities of Earthquake Occurrence on the San Andreas Fault Based on Geologic Data: EOS, Vol. 62, No. 17, p. 332. Draft EIR, Bethel Island Area Specific Plan, Prepared for Contra Costa County, February 1988, LSA H EDA 602. r• Earth Science Associates, 1982; Seismotectonic Study of Contra Loma Dam and Vicinity. Report to the United States Bureau of Reclamation. , Finch, M. O. , 1985; Earthquake Damage in the Sacramento - San " Joaquin Delta; California Geology, Vol. 38, No. 2 . , Helley, E. J. and Herd, D. G. , 1977 ; Maps showing faults with quaternary displacement, Northeastern San Francisco Bay Region, California, USCG Map MF-881. Herd, D. G. , 1979; Neotectonic framework of Central Coastal California and its Implications to Microzonation of the San Francisco Bay Region USGS Society Circular 807. Jennings, C. W. , 1975; Fault Map of California with locations of Volcanos, Thermal Springs, and Thermal Wells, CDMG, Geologic Data Map Series. Joyner, W. B. , and Boore, D. M. , 1981; Peak Horizontal Acceleration and Velocity from Strong-Motion records including records from the 1979 Imperial Valley, California Earthquake Bulletin of the Seismological society of America, Vol. 71, No. 6, December. . McGuire, R. K. , 1978; Seismic Ground Motion Parameter Relations, ASCE Journal of the Geotechnical Engineering Division, Vol. 104, No. GT-4 April. Nilsen, T. H. , 1975; Preliminary Photo Interpretation Map of Landslide and other surficial deposits of the Brentwood 7-1/2 ' Quadrangle, Contra Costa County, California. Prokopovich, N. P. , 1985; Subsidence of Peat in California and Florida, Bulletin of the Association of Engineering Geologists, Vol. XXII, No. 4. Repenning, C. A. , 1960; Geologic Summary of the Central Valley of California with Reference to Disposal of Liquid Radioactive Waste, USGS TEI Report 769. Salinas Daily Index, 1906; Latest Earthquake news, the Santa Fe's �( Condition, April 20, Vol. 19, No. 124, p.3. �i San Francisco Chronicle, 1906; "River Changed by Trembler", May 1, Vol. 88, No. 106. Sedigh, K. , 1983; Considerations in the Development of Site Specific Spectra, Proceedings of the XXII Conference, USGS Open File Report 83-845. Seed, H. B. , Tokimatsu, K. , Harder, L. F. , and Chung, R. M. , 1984 ; the Influence of SPT Procedures in Soil Liquefaction Resistance Evaluations, Report No. UBC/EERC - 84/151, Earthquake _ Engineering Research Center, University of California, Berkeley. Weir, W. W. , 1950; Subsidence of the Peat Lands of the Sacramento San Joaquin Delta, California, Hilgardia, Vol. 20, No. 3. Wesson, R. L. , Helley, E. J. , Lajoie, K. R. , Wentworth, C. M. , 1975; Faults and Future Earthquakes in Studies for the Seismic Zonation of the San Francisco Bay Region. USGS Professional Paper 941-A. Woodward-Clyde Consultants, 1986; Revisions of Portions of Contra Costa County Seismic Safety Element, January. GOLF CoURSE t -S kerl AT Ay vi I 7 WA V 4- RaW Park x. iU c8m 2 et Isla e %Z S M, 51 c CI x 'am 7 'pimping__. Sta V: 0 S. All H 0 <1 x PROJECT SITE PROJECT G) %L 0 U H <D'�—. G A S Y % jko I .......... ............. .... ....... ).k am f (zi cc z Bm74 0 SLOUGH FIELD 4 ........... If as A' I H 0 L L ........... ff A . ....... ... x a .......... t ---------- C, % Fish ScreensSCALE Gas Well Tide Gage 0 2000 4000 ft Rock \,� Sloagh Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA VICINITY MAP PROJECT NO. 11-1956-01 ■Iii- ��� �` `• �I i 111!!! o� `+'` 611 1/��I •� � � • ♦ � ��•.' JN OIIIJInlip- s1��1 lam- �r r K.� aCPT-IS CPT-19 •6 • s�� - ff CPT-17 0 UIl \ a �W. CPT-48- w • Bethel • o I A Island Area Project ContraEast • County, : •RING LOCATION i a o f l Y ~ y T 0 o M w E c •-~ � N Q vtS' MvVrl— a V ., wtL ooa•� � •,..-tet\\\ � a � Q t 7' ' -'~• m Z ~ IL COuj kv � %{ sae'rrloo Erf3• � �� � �''a. • "1 1 O o 0 117, cl cr• �+�./ � key��e � \ o o`W" C r a > m O rl d 0 ol O gj j 10 v f ;.t+ • t �. ��A� ��• wr • �f!.°P°m .•O,�i I iisda�d�!lPr/` s�Ih I ' P fif6Nf ! 1 ri • L� • 4 t.. .+ l 1 t a - ! �}i t % � •• ! 2 �, s, .Q 7 j: it Y i 3 W M • Q �I ' � J o a IIJ ' e Ch E`fi� 3 lJ [ 44 g: 4 4a V03 5 y t 9 G �`E 8 s' c� W E ��� ° S 'ES.fil+. cc Y w o.... Ig; .1 a �° �: < a $Ir° e ! acr.[`oe •t ; d A W 3 - r` ; m WCLCC7 `o ° V tc ..1 g6 L ^! tl!^! N .7E i � �`9 cvZ •CC < OG cave z- V 7 e 4!a ! ¢ W 66� E��- ["°![ m �Oag"; epi :3�' 2. � S:o 40l�:`�SaS�°r.'1 v ' os,_Y ;so a ier� ace sus` s a mui ui H --ss-�5 o H.I a -j _ O r u W O 6 F I I 7 I yl 11 ... r �,� . •�'I El CL. o _ r- r ?• c. ..-fir- U ....-rr — 01_ -� CL �ON� yY.i•_... _:'� / �E_ .GSA. IY �._....:....:: L__;:.. O Y• \. .: J' '�•.` �yil .0 ,:.:::':.":.:.:. /ter/ _ _ Sri$ R { lo, .rte y p0 �I,•' r n«;z; •,gyp �:�:::;: "� .;. :•./• ..f =� ' :I t 1 -� 'l ' ,'�r��aoj• �•I .. .. E w dvr ^- .• .,: .::;,�y:... a I.1� C:P `, 1\ ,pn/ J. v e a• o• C �.G"- `l 1 I��_-_ .••( .�a1 1��� � 2•i� rll�':.''•' `�' I u 1��y _ I� i UNIFIED SOIL CLASSIFICATION SYSTEM MAJOR DIVISIONS LTR DESCRtPTION MAJOR DIVISIONS LTR DESCRIPTION GV Veit-graded gravels or gravel sand ML Inorganic silts and very fine mixtures, little or no fines. sands, rock flour, silty or GRAVEL GP Poorly-graded gravels or gravel SiLTS clayey fine sands or clayey silts with slight plasticity. AND sand mixture, little or no fines. AND CL Inorganic clays of low to medium GRAVELLY GM Silty gravels. gravel-sand-clay CLAYS , Plasticity, gravelly clays. sandy SOILS mixtures. LL<50 clays. silty clays, lean clays. COARSE GC Clayey gravels. gravel-sand-clay FINE OL Organic silts and organic silt- GRAINED GRAINED mixtures. clays of tow plasticity SOILS SV Veli-graded sands or gravelly MN Inorganic silts, micaceous or ' SOILS diatomaceous fine sandy or silty sands, little or no fines. SILTS soils. elastic silts SAND SP Poorly-graded sands or gravelly AND CM Inorganic clays of high plasticity. AND sands. tittle or no fines. CLAYS fat clays. SANDY SM Silty sands, sand-silt mixtures. LL>$0 ON Organic clays of medium to high ' SOILS I plasticity. SC Clayey sands, sand-clay mixtures. NIGNLY Pt Peat and other highly organic ORGANIC SOILS soils. Piezometer Standard Penetration Split Spoon Sampler Concrete Modified California Sampler ' t- 3/8" Bentonite m Shelby Tube Sampler Pellets ' Water level first observed in boring #2/12 Sand T Water level observed in boring following drilling NFWE No Free Water Encountered , NOTE: Blow count represents the number of blows of ' a 140-pound hammer falling 30 inches per blow required to drive a sampler through the last 12 inches of an 18-inch penetration. NOTE: The line se ar ating strata on the logs represent approximate boundaries only. The actual transition may be gradual. No Warranty is provided as to the continuity of soil strata between borings-. Logs represent the soil section observed at the boring location on the .date of drilling only. Bethel Island Area Project PLATE klqKLEINFELDER East Contra Costa County, CA A-1 PROJECT No. 11-1956-01 BORING LOG LEGEND J2iil Brie: 2 ^r I Datelr D. Logged By Larry - 2.0 in. O.D. 1.4 in. I.D., Shelby Tube Lo gg Sampler - 2.8 in. dia. ' Total Depth: 128.5 ft Hammer Wt 140 lbs. FIELD LABORATORY N s r. DESCRIPTION Ir 1 L C M 41 .N E 3 M 1 ori ti a ai CL e -4 0 0 0 0 0 4 i ;v : a Surface Elevation: Approximately -7 ft G N m OD EU\ U 0 i+ O H a. TOPSOIL: VERY SANDY CLAY (CL) - 10 2.5 black, low plasticity, very moist to slightly wet --mil rnnts, fine to medium grained q nd ' SILTY SAND,(SM) - loose, gray grown, fine 1 sand, wet 5 *3 17 - medium dense, blue-gray, fine to medium grained coarse sand, 7 to 7.5 ft 1 10 15 -#4=100% -#200=32% - very clean sand 12 to 15 ft - slightly cemented layer at 13.5 ft 15 79 -#200=12% - very dense, fine to medium grained with ' pyrite, saturated below 15 ft 20- 60 ' - brown, with a very silty clay layer, from 20.3 to 21 ft 25 89 -#4=100% - slightly silty below 25 ft -#200=6% 30 r No recnvery 35 ' Bethel Island Area Project PLATE K LEINF ELDER East Contra .Costa County, CA ' PROJECT NO. 11-1956-01 LOG OF BORING NO. B-1 A-2 li=r D LABOR:/-.TORY i I 461 w , ;RIFITION 4J � 3 M M4 Q 0 • N O. E C a C i- -1 C E L {. L M c a° a m c o u E v°x 0 v"i 4J c F a (Continued from previous plate) 40 loo/ 106 21 -#200=9% $" - sandy clay layer 42 to 43.5 ft 45 SILTY CLAY (CH) - hard, Light gray, high plasticity, slightly wet 50 54 95 30 1.7 2.5 55 VERY SILTY SAND (SM) - brown, fine sand, lots of pyrite, saturated 47 , SANDY SILT (ML) - medium dense, Ebrown,some mottled staining, wet, lots of p 60 SILTY SAND (SM) - dense, brown, fine sand, wet, pyrite 65 70— 'N $7/ SAND (SP) - very dense, gray, medium 4". grained, saturated 75 Bethel island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. i 1-1956-01 LOG OF BORING NO. B-I A-3 F ELD 4• a i 41 N �V t L Ca 11 i • C. E O 3C4- M C E L 4. z R C n° N m a n ° s n x a 0 4J o 4 a (Continued from previous plate) SAND (SW) - dense, well-graded, est. 5% fines 80 85 94/ -#200=5% 4" 90 SILTY SAND (SM) - blue-gray, fine sand, saturated 95 100 - very silty below 100 ft 105 110 58 115 Bethel Island Area Project PLATE k" K L E l N F E L Q E R East Contra Costa County, CA �b-01 LOG OF BORING NO. B-1 A-4 PROJECT NO. 1 1-19 � i - ! ..-ORATORY L DES, L M a+ M t •-4 M �•+ -W n L C L M 0. E a 71 C w •a C E L i- t M C 0 4 m n o u s v'. coy u{'i o a (Continued from previous plate) 120 SILTY CLAY (CH) - blue-gray, high plasticity, wet , 125 SILTY SAND (SM) - very dense, blue-gray, ' fine sand, saturated, lots of pyrite 98 130 135 140- 145 40 145 150- 155 Bethel Island Area Project PLATE I k" K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-1 A-5 I PROJECT NO. 11-1956-01 I ✓Indified California 5a:nnl^- O r, Date Completed: 5116/88 _-.0 in. LD. a g Spht . Star��'ar --� :. Logged By Larry Goldfarb 2.0 in. O.D. I.4 in. I.D. Total Depth: 54.5 ft Hammer Wt: 140 lbs. FIELD LABORATORY w ,, • a r k DESCRIPTION i. 31 L 43 O V4J 3 41 • -i 4, r L L L • 41 a 3Ji 41 tL E a 3 C 4. -•i C £ L t. L M C a° N m cL o u E 0 x 0 vii 4J o � a• Surface Elevation: Approximately -6 ft TOPSOIL 12 1.5 CLAYEY SILT (ML) - stiff, dark brown, low to medium plasticity, very moist to slightly wet, iron stained, roots. VERY SILTY SANE? (SM) - loose, brown, 5 6 fine to medium sand, wet 20 -#200=24% - silty at 5 ft - medium dense, silty below 7 ft 10 14 -#200=22% 24 15 - slightly silty below 14 ft 20 57 -#4=100% - very dense below 20 ft -#200=7% r 25 J. 30—,r\ 86 35 Bethel Island Area Project PLATE K L E I N F E L Q E R East Contra Costa County, CA PROJECT No. 11-1956-01 LOG OF BORING NO. B-2 A-6 I 3 L IJ M .0 r t .at R --4 A Y i C M E a c 1,. ..4 C E L it C M C L r u o 0 o u a r Continued from previous plate) a N m oo ED U ui 41 o � a ( P P } - increase in silt content at 37 ft 40 Q 45 50 SILTY CLAY (CH) - very hard, light brown, high plasticity, slightly wet 65 TY=1.2 tsf 3.2 55 60- 65 70 75 Bethel Island Area Project PLATE k" K L E IN F E L D .E R East Contra Costa County, CA LOG OF BORING NO. B-2 A-7 PROJECT NO. 11-1956-01 Sampier i.-indified Cs!;f--iF Sn7nnier - 7.f- in, 17�.D 2.0 in. 1.D., Standard-Split S000r- Sampler - 2 Logged By: Larry Goldfarb .0 in. O.D. 1.4 in. I.D. Total Depth: 54.5 ft Hammer Wt-- 140 lbs. FIELD LABORATORY DESCRIPTION a C a 3c C 4J 0 a * 0 CL E a 3 :x r- .4 c 4' E B- L' -- 1 0'J c a 4 -4 L ce 0 a 0 a 4J 0 4J a 8 face Elevation: Approximately 0 ft a W M 0 3 EL r X L) V) 0 a. Sur SILTY SAND (SM) - very dense, brown, fine sand, no cementation, dry, some iron 59 staining well cemented at 2.5 ft 5 61 fine to medium grained, very moist dense from 6 to 20 ft 44 J: slightly wet at 8.5 ft 10- 43 -#4=100% gray, saturated below 10 ft -#200-6% slightly silty below 10.5 ft 'T 15 -S39 20 61 -#200=6% J dense to very dense below 20 ft 25 30 47 -#4=100% medium grained sand below 30 ft S -#200=10% f 3.) Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 LOG OF BORING NO. B-3 A-8 '. F.rET LABORATORY � s.+ � — --�-�7--•,^+fir '� � 3 M Ma 0 • +� a -0i Lr O 00 O .N 0 4 M 0 n m m a s E n x v U) v 0 1- a (Continued from previous plate) 40— sandy silt Layer from 42.5 to 43.5 ft 45 SILTY CLAY(CH) - hard brown high 50 plasticity, slightly wet $ i 62 104 25 2.5 3.2 , 55 60- 65 70- 75 , Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROD ECT NO. 11-1956-01 LOG OF BORING N0. B-3 A-9 Date Completed: - ' Meleah Ashford - 2.0 in. •L• ` '- - L•- -Sheibv T;.-e Logged By: Sampler - 2.8 in. dia. Total Depth: 74.5 ft Hammer Wt: 140 lbs. rFIELD LABORATORY DESCRIPTION 41 CL 3 a NV M a 4 CL m ° L i n o a 0 .`J a "r Surface Elevation: Approximately -6 ft o U) m C3 11 sox o 0 .01 a ' SANDY CLAY (CL) - stiff, brown, low plasticity, moist 16 117 18 1.2 3.0 ' 5 22 SILTY SAND (SM) - medium dense, gray, ' -#200=20% fine to medium grained, saturated, some comented nodules SAND (SP) - dense to very dense, gray, fine 10 36 grained, saturated 83 1 15 i 75 -#200=8% ' 20 - slightly silty at 19 ft SANDY CLAY (CL) - hard, gray, low ' plasticity, moist 25 SAND (SP) - very dense, brown/gray, fine to ' medium grained, saturated 1 30 86 i35 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA iPROJECT NO. 11-1956-01 LOG OF BORING NO. B-4 A-10 1 MELD LABORATORY i DESCRIPTION w L A+ : VAJ 3 c 01 M � 3 M M Q r a O. E O 3 c t- M [ E L �- G M C o -a s ■ u o a o 4+ • ++ !Continued from previous O N m a0 XUX U N +� t a f Q plate) 40 $/ 45 SILTY CLAY (CL) - hard, brown and gray, 50 low plasticity, moist SS 2.0 55 60- 65 0 65 97 30 3.7 3.0 '- 70 , SAND (SP) - very dense, brown, fine to 83/ medium grained, saturated 75 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-4 A-11 PROJECT NO. 11-1956-01 0.5 c 0.4 r ; r `o y j � Ct r � r a a i m m u 0.3 a '> o. b CP ` Vv a=0.30 c ' a 0.2 3'bc O 'p a=0.20 `o CC N sn 'v 0.1 - 0- 0 103.214 16 IS 20 30 40 Modified Penetration Resistance, Ni-biowslft Chart for evaluation of liquefaction potential of sands for earthquakes of different magnitudes. Source; Seed and ldriss(1982). Bethel !stand Area Project PLATE ? ' •- _ ? n E _? 'E;st Contra Costa County, C3 - -- - _ AJEFAC T ION POTE"';:.=._ - e 4 it'!Alm". •ij,,' ♦ ,s •� � %////fit►� ,�b"\t�►1�.'�� aQIF` ,1 an WX t Um Mg r.- ••:5 mom ♦fs fiJ ra�it Qt1 I �� •tl Z f �ot-�0 ��•�!�� I fI ► xia `>�,�j•��lihi Illiyi►i�,�j� `�„��I'i9:`�:,Is¢�� }�ti��-». 1-7 EW 40- '�Z �"'' � ^a- �: 4 ..�.mss .'^�+` . _ lug C�Rnt��♦• �� � ''fes---'-"—.: .�'` ��'�:• � • +t 1' - ■!Em•trE� c s j``�! y ".�'�► lr�`r► rye • 1� i • -� - . c;�`► rill ii Y i r' • -• � •`nom .v► �� w • r1 bar: 100 kPa«1.02 kg/cm2.. 1 tsf 10DD 10 12 11 � 9 m L D100 1 v M oNE CA 6 L 0 5 m 4 0 10 3 C 0 ' U 1 1 2 1 o 1 2 9 4 5 O 7 8 Friction Ratio C%) ' Zone Soil Behaviour Type Qc/N 1) Sensitive fine grained 2 2) Organic material 1 3) Clay 1 4) Silty clay to clay 1.5 5) Clayey silt to silty clay 2 6) Sandy silt to clayey silt 2.5 ' 7) Silty sand to sandy silt 3 8) Sand to silty sand 4 9) Sand 5 10) Gravelly sand to sand 6 11) very stiff fine grained (*) 1 12) Sand to clayey sand (*) 2 Overconsolidated or cemented UBC Simplified Soil Behaviour Type Chart for ' Standard Electronic Friction Cone Showing Proposed Zone of Potentially Liquefiable Soils (After Robertson and Campanella, 1983) Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO, 11-1956-01 BEHAVIOR CHART 7 CONE SOIL EH SACRAMENTO 20 km t i I Ar 0 6 to km e � A. ANTIOCN 1 srouro� PROJECT SITE 3 .... A t<> t 5 --- G CAUFORNU AWEnuCT \./ 7 PUMPINGDELTA PLANT (DWR)� / ���j 1 � urwreu ED , TRACY PUMPIN PLANT(USBR) �—DELTA-MENDOTA CANAL Map sho%king maximum amount of subsidence on individual islands (based on an interpretation of USGS topographic quadrangle maps). Maximum subsidence: I)less 1.5 m;2) 1.6 to 3 m;3)3.1 to 4.5 m:4)4.6 to 6 m; S)over 6 m;6)not reclaimed. permanently flooded islands(excluding purposely flooded Clifton Court Forebay of the SWP),and 7)generalized"0-elevation contour. Source: Prokopovich - (1985) Bethel Island Area Project PLATE , K LEINF ELDER East Contra Costa County, CA DELTA SUBSIDENCE 8 , PROJECT NO. 11-1956-01 -•cdiried Caiiforni2 nlp� Sart_ .. - Daie Completed:__ >;MISS .-.0 in. I.D.. Standard Spiit Sp031n Sar:oler - 2.0 in. O.D. 1.4 in. I.D. Logged By: Meleah Ashford Total Depth: 60.0 ft Hammer Wt: 140 lbs. FIELD LABORATORY 4 �, • w DESCRIPTION ,; t r .-2 3 a a-, 0. •C • � 0. E 0 31 C 4- -4 C E L .0 . M a C • • -a L • 0 0 0 0 .0 a u • • Surface Elevation. Approximately -4 ft n to m a U. E U X U N 4J O a. SILTY SAND (SM) - loose, brown, = 7 fine-grained, dry to moist 5 SANDY CLAY (CL) - stiff, brown, with .� 10 some organics, moist -#200=33% 1023 -#200=44% VERY SILTY SAND (SM) - medium dense, brown, fine grained, saturated 15 32 - decreased silt content at 15 ft 20 SANDY CLAY (CL) - very stiff, brown, moist 9" SAND (SP) - very dense, brown, 25 fine-grained, saturated 30- 78 -#4=100% -#200=9% - slightly silty at 33 ft 35 Bethel Island Area Project PLATE K L E IN F E LD E R East Contra Costa County, CA PROJECT NO. 11-1956-01 LOG OF BORING NO. B-5 A-12 LABORATORY ' L N r ^ L: scpli.i; M L � 3 q q� [L r r y M a -4 L B o a o a 4J i y i (Continued from previous plate) O N Q3 100 E UX U 4) i+ O h Q 40- 73/ 12" 45 50- 55 72 CLAY (CH) - hard, brown, moist i 6fl _ 65 70 7� Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-196-01 LOG OF BORING NO. B-5 A-13 Sampler: Modified California Sampler - 2.5 in. O.D. j Date Cornpietcc: 9.19/89 2.0 in. ;.u., S.an,:ard Split S;)nnn 'Sam ler Logged By: Meleah Ashford - 2.0 in. O.D. 1,4 in. I.D., Shelbv Tube Sampler --2.8 in. dia. Total Depth: 65.0 ft Hammer Wt: 140 lbs. FIELD LABORATORY DESCRIPTION 1 :1 L 4 : V 41 3 C C1 M -4 0 -4 41M a -°4 a n v 0 0 a � N 4 : : Surface Elevation: Approximately -3 ft Li to M a s Q. E U a N O h 0. SILTY SAND (SM) - dark brown, dry 25 1.5 3.5 SANDY CLAY(CL) - very stiff, brown, fine-grained sand, moist 5 SAND (SP) - medium dense, brown, fine grained, saturated 15 -#4=99% _#2Q0=11% - slighty silty below 6.5 ft l0 31 -#200=8% 15 20-- 35 SANDY CLAY (CL) - brown, fine grained sand 25 SAND (SP) - very dense, brown, fine grained, saturated I 30 73/ - 12" 35 Bethel Island Area Project PLATE K LEIN FELDER East Contra Costa County, CA LOG OF BORING NO. B-6 A-24 PROJECT NO. 11-1956-01 i Lr,KL,L. .i,.; 4 71 3 0, r CL F a a C -4 C E L� %-- a � o L r u G o o + Nr o r +oLr+ M +NC. (Continued from Previous plate) c N m oEUo N a 40- 88/ 9" 4 ' 5 50- 55 0 55 SILTY CLAY (CL) - hard, brown and gray, , 4.5+ saturated - some silty seams 60 , - silt seam 61 to 61.5 ft 65 r 70- 75 Bethel Island Area Project PLATE , K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-6 A-15 , PROJECT NO. 11-1956-01 J r 1 Late Cor.:p: - 2.0 in. 1.D.. Standard Split Soon Samuier Logged By: Tim Hunttina - 2.0 in. O.D. 1.4 in. I.D. ; Total Depth: 66.5 ft Hammer We 140 lbs. I FIELD LABORATORY DESCRIPTION � 3 a M�3 L 41 4J d a d CL E a 3 C t. -4 C E L i- C a C o rn m o o u E coy X n° 0 4J o � a Surface Elevation: Approximately -6 ft SANDY SILT (ML) - soft to firm, dark brown to black, fine grained sand, dry 21 108 191.5 1.0 rSANDY CLAY (CL) -very stiff, mottled 5 gray, dark brown, orange and tan, trace fine gravel, moist _ ' 35 2.2 LL = 40 PI = 22 - wet at 7 ft - blue-gray at 8 ft 10 12 SILTY SAND (SM) - medium dense, blue-gray, fine to medium sand, saturated 15 37 -#4=100°Xo SILTY SAND SM - dense ' ( ) , gray brown, fine -#200=24°x6 to medium sand, saturated 20 55 - very dense, brown, increased silt below 20 ft r 25 - light brown tense of clayey sand at 25 ft 30 75 35 Bethel Island Area Project PLA7F7 KLEINFE L D E R East Contra Costa County, CA PROJECT NO. 11-196-01 LOG OF BORING NO. B-7 A-16 DE&CRIPTION w L V a 3 r MV A r r .0 `« M .4 L a a Q O a V r .0 r r a m m a s s:v.0 o ui +1 o � a (Continued from previous plate) SELTY SAND (SM) - continued 40- 94/ 10" 45 - intermittent lenses of silty and clayey sand below 45 ft 50 �. SILTY CLAY (CL) - hard, olive brown mottled w/orange and light tan silt, trace 55 concretion, trace fine to medium sand, 39 2.5 saturated 4.0 60 r A _ 65 82/. SILTY SAND (SM) - very dense, brown and blue-gray , 70- 75 Bethel Island Area Project, PLATE KLEINFELDER East Contra Costa County, CA LOG OF BORING NO. B-7 A-17 PROJECT' NO. 11-196-01 Date Completed: 9120 Logged By. Tim Hunttina - 2.0 ir.. C.D. ' Total Depth: 61.0 ft Hammer Wt: 140 lbs. FIELD LABORATORY w si • M i. DESCRIPTION #- a 3 c 440 i 3 M u a c 0 +. CL a a a cw a .�+ n on c e 1 M r a C Surface Elevation: Approximately -7 ft n a -+ Lmo o �+ • • C, 0m cia snx o a 4J a a SANDY CLAY.(CL) - firm, dark brown, dry 13 CLAYEY SAND (SC) - stiff, dark brown, gray and orange mixed, medium plasticity, 5 moist 17 96 29 1.3 SANDY CLAY (CL) - stiff to very stiff, brown and blue gray, low to medium plasticity, fine sand, moist SAND (SP) - dense, blue gray, fine to 10—Nmedium grained, saturated 39 -w4=100% #200=4% IS 20 SANDY CLAY (CL) - light brown, low plasticity, fine sand SAND (SP) - very"dense blue gray and75 brown wjtrace of orange, fine to medium 25 sand, saturated 30 Bethel Island Area Project PLATE K L E l N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-8 A-18 PROJECT NO. 11-19-56-01 �D 1 L C . �+ 4 r � c r a ++ S .1 r -•1 �J r L C L r 'a E o a c U 0 c e 1 �- t ■ c (Continued from previous plate) • ■ .� L r o 0 0 0 �+ r si r ■ o N m 13 Eox v +� o a r 4D r SANDY CLAY (CL) - light brown, low plasticity 45 r 68 SAND (SP) - dense, brown, fine to medium grained, some silt, saturated , 50 ' SANDY CLAY (CH) - light brown, trace 55 fine sand, medium to high plasticity - r 60 SAND (SP) - brown, fine to medium grained, saturated 65 1 70 r 75 1 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-8 A-19 PROJECT NO. 11-1956-01 i sampler. Modified California Sari-pie- - 2.5 in. O.D. Date Completed: 9%20/88 2.0 in. I D. Standard Spoon Sampler - 2.0 in. O.D. 1.4 in. I.D. Logged By: Tim Hunttinrt Total Depth: 67.5 ft Hammer Wt: 140 lbs. FIELD LABORATORY 4 DESCRIPTION L 4J 4J 41 � a w r� a. ON L o +•+ • M a -4 i a n o 0 0 M 41 i Surface Elevation: Approximately -6 ft O N m DD EU\ v N N O ►- a SILTY SANDY CLAY (CL) - firm, dark brown, dry 32 98 27 1.2 1,5 very stiff, moist below 2 ft - stiff, blue gray, orange and brown, low 5 plasticity, fine to medum sand below 3 ft 15 - increased silt, firm, some concretions, light blue gray below 6 ft 10 -#4=10096 -#200=18% SILTY SAND (SM) - medium dense, blue gray w/trace orange and brown, fine to medium sand, trace silt, moist ? 15 gg - dense below 15 ft 20 25 - sandy clay layer between 24 to 24.5 ft ' 77/ - very dense below 25 ft 12" 30 35 Bethel Island Area Project PLATE , CA East Contra Costa County,Y LOG OF BORING NO. B-9 A-20 PROJECT NO. 11-1956-01 riLD a. , 4 r r BORATORY DESCRIPTION L C M 0 ■ � CL 3 M M, , a r +. a E D 7Cw -a C. E L •. C r C r a w+ L r a o a a +� r ++ r r (Continued from previous plate) O N to 00 a EUX a 01 O F a I 40- 45 I 55 50 SILTY CLAY (CL) - hard, olive brown and _ tan w/some orange, some fine sand I 55 64/ 3.0 - clayey sand lense between 55.5 and 56 ft 12" - lense of sandy clay/clayey sand, very dense, brown and rust 60- 65 , 70 r 75 I Bethel Island Area Project PLATE ' k1l K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-9 A-21 PROJECT NO. 11-1956-01 ' r • 7 Szrr:rW!.-- ' -f zat: Completed: 9,21/88 2.0. in. T.D., SlaIIGZTSQh', Log-ed By: Tim Huritting - 2.0 in. O.D. 1.4 in. I.D. 0 Total Depth: 56.5 ft Hammer Wt:- 140 lbs. FIELD LABORATORY .j a ; c 4-- DESCRIPTION L 41 0 4j 3 C -4 Aj a OL CO L CL E 0 :1 me s- .0 4cj Ea L %. C -4 L 8 0 .0 0 0 4j 0 8 Surface Elevation: Approximately -6 ft O U) M 00 CL E C3 (3 X V 0 SANDY SELT (NM) - dark brown, dry 7 SILTY SAND (SM) - loose, brown to dark brown and orange, fine to medium grained, 5 dry to moist 4 -#4=10096 blue gray with little grassy fibers, -#200=10% saturated below 6 ft slightly silty at 7 ft medium dense below 8 ft 10- 16 -#200=12% trace concretions below 11 ft 15 48 dense, gray to brown below 15 ft V.. 20- 84 very dense below 20 ft 25 30- 35 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-10 A-22 PROJECT NO. 11-1956-01 FIEL- . DESCRIPTION w 7 L C M � ■ L -� • -� 4+ a L C L M O. E 0 :1 C w .C E L i- C ■ C • a -+ L a o 0 0 a + • ++ a • Continued from previous CI 93 N m O \ +art E UU }+ 0 1- a ( P plate) 40 78/ - light brown at 40 ft 11" 45 - increased clay content below 46 ft SANDY CLAY (CL) - hard, olive and light 50 tan, some silt and brown and orange sand 78 4.2 SANDY SELT (NII.) - medium dense, 55 medium brown w/orange multicoloring 18 Ilk 60- 65 0 65 i 70 1 1 75 1 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA A-23 LOG OF BORING NO. B-10 ' PROJECT NO. 11-1956-01 SaInnier- 2.5 i,-- O.D. Completed: 9 --1 !88 2.0 in. C.---. !.4 in. I.D. Logged By: Tim Huntting Total Depth: 70.0 ft Hammer Wt- 140 lbs. FIELD LABORATORY DESCRIPTION 3 L 4J AJ 3 c 13 .0 -4 4J 6 L C L 0 4.1 a 3 4, CL 0- E 13 3 C*4- -04 C E LN fi- 6 c 4 -4 L a U 0 a a 4J V 4J 8 1 Surface Elevation: Approximately 7 ft O 0) 0 00 Q. r UX 0 V) 4J 0 a. SILTY SAND (SM) - very dense, gray, fine to medium grained, dry 'T 53 orangish brown below 2.5 ft 5 29 medium dense, wet, 6 to 15 ft 10- 26 15 36 dense below 15 ft 20-1 45 medium brown, multicolored below 20 ft 25 sandy silt layer 27 to 28 ft 30- 35 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 LOG OF BORING NO. B-11 A-24- L4 4J S •-•i -moi 41 • i C L • Q E a :1C 4- »ai C E L 4» L M C • • -+ L • a o a 044 a 4J • • (Continued from previous plate) CI Uf m 00 E U\ U N +1 0 F- a 40—s78/ - very dense, blue gray below 40 ft I2" 45 50- 55 SANDY SILTY CLAY (CH) - hard, olive brown w/dark brown and orange, blue gray and light tan mottling, medium to high plasticity, little concretions, moist to wet 60 58 3.5 65 76- 75 Bethel Island Area Project PLATE MIKLEINFELDER East Contra Costa County, CA PROJECT NO. 11-I956-01 LOG OF BORING NO. B-11 A-25 t�-���di"in :i"orr.ir S: _ Date Completed: 9/21/88 2.0 in. I.D. - Standard Sc" S'2o.-,r. _ ' mpi r Logged By Tim Hunttina - 2.0 in. O.D. 1.4 in. I.D. Total Depth: 56.5 ft Hammer We 140 lbs. FIELD LABORATORY Ai u ; r DESCRIPTION •. a L.'J 04 E -� 3 M M 4! O. a Y *. a E a a C i- -w C E L 1,. t M C u ° ° s O m c o E UX 0 U) Zo aSurface Elevation: Approximately -7 ft SILTY SAND (SM) - medium dense, gray, fine to medium grained, dry 15 _#20005% - orange grading to light brown, dry to moist - slighty silty at 3 ft 5 15 -#4=100% - blue to dark gray, wet, trace concretion -#zoo=15% 10- 7 - ver silt y y, loose, 10 to 15 ft 15 69 - very dense below 15 ft 20-- 86/ 12" 1 25 - brown below 26 ft 30-- 55 JJ 35 1 Bethel Island Area Project PLATE 1 k" K L E I N F E L D ER East Contra Costa County, CA PROJECT NO. 11-1956-01 LOG OF BORING NO. B-12 A-26 FITELDORY DESCRIPTION 1. C L 0 C m E 0 3 C k. C F -4 L a 0 a a a AJ a 4J vious plate) a 0 (Continued from pre 0 0 M Goa EU 0 (n, 0 increased clay content below 36 ft SANDY SILTY CLAY (CL) - hard, olive 89/ brown to tan, moist 12' 40- 45 - 89/ layers of sandy clay and clayey sand below 10" 45 ft 50 SANDY CLAY (CL) - blue-gray, medium plasticity, fine to medium sand 55 - 51 CLAYEY SILT (ML) very stiff, greenish brown, very fine sand, moist 60- 65 - 70- 75 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-12 A-27 PROJECT NO. 11-1956-01 rri_ Sam 1,7- - - - in. 0. Date Compictec: c 2 i/5£ _ _ =nozri; S;i Sam:-;i--,- _ 2.0 in. ,.D. 1.4 in. I.D. Logged By: Tim Hunttin� Total Depth: 61.5 ft Hammer Wt: 140 lbs. FIELD LABORATORY r- DESCRIPTION 4J d t L+1 /1 a. M � a n i 41 o. a r Z +• 0. E o 71 C r- -•4 C E L S L a C 0 .� L • o 0 0 0 +� a r Surface Elevation: Approximately -8 ft o N m oo EUS U 0 +� o a SILTY SAND (SM) - medium dense, brown and orange, medium to fine sand, moist 12 - wet below 2 ft 5 15 -#4=100% -#200=9% - slightly silty at 6 ft 10 15 - very silty 9 to 11 ft - very dense below 13 ft i 55 15 e 1 20—' 0 92 -,�,�4-_ 10096 -#200=8% - slightly silty at 21 ft 25 - 30- 62 35 Bethel Island Area Project PLATE . K LEIN FELDER East Contra Costa County, CA LOG OF BORING NO. B-13 I A-28 - PROJECT NO. 11-1956-01 FIELD LABORATORY41 - 41 a 3 M Q r 1 E .°, L i o n o o 41 M Continued from previous plate) o N m 0 soX, a an 41 o H a SILTY CLAY (CH) - hard, light brown, medium to high plasticity, wet 40 38 2.7 �r 45 50 CLAYEY SILT (NII ) - very stiff, brown, medium plasticity, some pyrite, wet 55 n 60 31 65 70- 75 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-13 A-29 PROJECT NO. 11-1956-01 Samrs-- az'. Corrip C-1 C-: 2/88 Logged By: Larry Goldfarb Total Depth:- 15.0 ft Hammer Wt: Wet Rotary FIELD LABORATORY 4J 41 2 ; z DESCRIPTION 1.AJa 41 D C a 01 3 -4 41 a L c L a a Q. E a 3 oc%- .0 2- ! c. .8c 4J a 4 -4 L 8 U 0 0 0 4J 0 4J Surface Elevation: Approximately -8 ft 0 1 V)l M 0 0 1�E U X 0 (0 4J 0 SILTY SAND (SM) - medium dense, brown, Log of orange sand, moist Boring medium to fine sand, wet 5 10 very silty from 9 to 11.ft — Piezometer Backfill very dense below 13 ft 15 20 25 30- 35 Bethel Island Area Project PLATE k" K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-11956-01 LOG OF BORING NO. P-1 A-30' . I Date Co ' 1 Logged By: Larry Goldfarb Total Depth: 15.0 ft Hammer Wt: Wet Rotary FIELD LABORATORY DESCRIPTION ♦. a i AJ M 4J M 41 CL 3 a M4' d 8c 4 Q E 0 7 %- C . C E L i L q C i e 0 0 0 0 ■ . Surface Elevation: Approximately -2 ft O m m CIG IL EU\ U N a+ G. f d SILTY SAND (SM) - dark brown, fine to =. Log of medium sand, dry Boring - slightly moist, gray brown below 3 ft 5 r 1 10 - some cementation to 10 ft Piezometer - very silty below 10 ft ' Backfill 15 rl 20- 25 0 25 - r 30 35 ' Bethel Island Area Project PLATE k" K L E I N.'F E L D E R East Contra Costa County, CA LOG OF BORING NO. P-2 A-31 PROJECT NO. 11-1956-01 ' r =:er. Logged By: Larry Goldfarb Total Depth: 15.0 ft Hammer We Wet Rotary FIELD LABORATORY 41 DESCRIPTION • 41 7 c i s +�+ � -a 3 M M++ a i i 4 CL a ° i U o a a 0 4`+. a � : Surface Elevation: Approximately -1 ft O N m 00 EU\ U 0 0 O F- a SILTY CLAY (CL) - dark brown, medium Lo of plasticity, moist, some coarse sand �. Boring - mottled gray below 2 ft a 5 SILTY SAND (SM) - brown, medium sand, saturated 10 - gray, decreased silt content below 9 ft Piezometer Backfill 15 20- 25 0 25 30- 5 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA ' A-32 LOG OF BORING NO. P-3 i PROJECT NO. I I-196-01 Date Sar^.ple I Logged By: - Larry Goldfarb Total Depth. 15.0 ft Hammer Wt: Wet Rotary FIELD LABORATORY r r DESCRIPTION f,. a L 41 r A ■ 4J 3 C El 4J 12 3 w 04,a ori a r r CL E a 7 ♦-C . C E L t a C r r -4L r 0 0 0 0 +1 r si r r Surface Elevation: Approximately -7 ft o rn m a s UX 0 0) 4 o � a �. SILTY SAND (SM) - dark brown, fine to =. Log of medium sand, moist Boring - brown, very moist to slightly wet below 3 ft S - gray, decreased silt content below 7 ft 10 Piezometer Backfill 1 r1 s 20- 25 30- 35 0 35 Bethel Island Area Project PLATE " K L E I N F E L D E R East Contra Costa County, CA i LOG OF BORING NO. P-4 A-33- PROJECT NO. I1-1956-01 ' t 1 POINT TO POINT PROFILE LINE JINT B-12 B-3 B-4 B-5 B-6 TSET 0 0 0 0 0 0 T .- -21- -30- -40- -50- -60- -70- -so- -901 20-30-40-50-60-70-80-90 0 1000 2000 3000 4000 5000 6000 7000 DISTANCE, feet Bethel Island Area Project PLATE KLEINFELDER East Contra Costa County, CA �O.7ECT NO. 11-1956-01 2-D PROFILE ALONG WEST SIDE A-34 ' 1 ` POINT TO POINT PROFILE LINE ANT B-13 B-11 B-10 B-1 B-8 SET 0 0 0 0 0 20 .i -20 Yzz i, -40 -60- -80- -100- -120- 1401 60-80-100-120140 0 2000 4000 6000 8000 DISTANCE, feet Bethel Island Area Project PLATE KLEINFELDER East Contra Costa County, CA 2-D PROFILE ALONG EAST SIDE A-35 OJECT NO. 11-1956-01 ' B—� B-9 0 a-y 0 0 YQI1;T 10 vt)Ity� YBpFILE LINE .---i'"'_ ,INr B-13 FSET 0 a r -lo -ZO -30 —40 s ��•3 _50 —60 100fl ?0 6000 5000 !, 4000 3000 �IST {get 2000 1400 _SU P rou•ect A r ! C 0 A Bethel Wand�sta Cnty -36. 1N� East Contra LONG CBN-�BR� E R 2`0 PRpFiLE A KLE � N 2CJECT NC• -$ B r2 B_5 Bo_'i BO 0 B... .... ... . ... .. 1� R�F11'E LixE B_d , 0 0 ,t -rp pa T p B-ia 0 ppll`t 8-11 B-3 0 �iNT B_i� 03 0 . ;FSET 0 20 v mt0 _20 i _60 so 1 -,Do 3aaaa _1.20 2�p00 2©000 15000 fact 1p000 �ZS�AµcEr Q�AtE sp00 Pc et _ _ida o of gethei island �'°5ta C°U"ty� CA 1� 37 East C°ntra C OS . , Gpc/tP I��'. E � _ ROF�L� ELS 2 � P ins, K 01 j1-1956 ',ECS µp. B-9 0 B-8 0 TO YOiN 0 vq B-5 SSE ..ip 1 1 -6p 6ppp app° -'j0 �0p0 3(JfJO ► {eet p`pSE �p0 Asea P r.°unt`1• CA 3$ 8 as tra C 1pfolp M3�te11+ Coll � 4Z pROF��E Ce rr 6_pr µ0- RO��Gj rn 1 w � r, Q a T C C u t9 A ✓ J d °� t � `L o N V .3 v .. �,.. s N o m uy N a Y Yd � H , U O '� U J N Y � W c Z Q ,n Y�a 'Z6 u+ Z � 'Z 7� 'c to w :, N N �^ ... Y � � � c � < H � r H � � C � �, I bar = IOOkPc = 1.02 kg/cm 2 400 SANDS 200 / SILTY SANDS / 100 1 80 / SANDY 60 SILTS Cr 40 AND SILTS /CLAYEY SILTS z 20 AND // Fr .1Z SILTY CLAYS < wCLAYS W 10 ''r / w8 z 6 - 0 L) PEAT 4 - 2 1 - 0 1 2 3 4 5 6 FRICTION RATIO , F R 1 SIMPLIFIED CLASSIFICATION CHART FOR STANDARD ELECTRIC FRICTION CONE FROM ROBERTSON AND CAMPANELLA. 1984. Bethel Island Area Project PLATE k'qK L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 CONE CLASSIFICATION CHART B-1 '3983) Hld3C1to ' Ip b N N O co � H W IL LL Q'O a o I 1 to N N p h o ^ Ol Q CO 1� m m M o E t CZ IL m 'O �d _ — _ — _ — — _ _ — — o _ _ _ a N 't Np h _p ^ Q a La ca 52 x Ln a 0 ^ o a p _ _ _ _ _ _ _ _ _ _ -... — _ _ — H -• IL °, th ' � O O t0 I N O_ O_ W 1 ° `a N 4 U O u tea° 41 C ' w pp In o � 6 W ° p L m c U ^ c y 0 0. v i ° IL > u p O 0 0 0 o < L 0 O Cr .�. °o_ o o ' o � Z u • ^LL Cr LL O N O ^ O (s-Ialaw) H1d30 Bethel Island Area Project PLATE K L E i N F E L D' E R East Contra Costa County, CA CONE PENETROMETER NO. 1 B-2 PROJECT NO. 11-19-56-01 1 0 to oto 0 40 c se ' to (L C Cr C2 CL a CL CD in in m 0 a h osh 0 M C, (D E ca C 4D C .0 3 0 0 W7 M 9n a x w 0 W ILC' - - — — — — — — — — - - - - - - -' — IDL I da C. CD in LJ ID Sn I- A = ;;I . w E t- a cc C c 1 7,!= . in L tL U a 4 41 1z C2 w C3 ' m a U C3 J (L > L) -J 41 L C vt L o CC CL 0 ri Q -i C3 1h H1d30 Bethel Island.Area Project PLATE J K L E ! N F �E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 CONE PENETROMETER NO. 2 B-3 0 to to to , V f 11CIO t ^ O ' C2 tna CL w In tu 0 N - 0 1 03 CD RI CL 0 0 itI — — — — — — — — — — — — — — — 16 0 4z a= gn O w SK W SOL 0. — — — — — — — — — — — — — — — — — — — IL w O to a 0 to Di O Q La Li ttJUJ .0 40 .0 I— cc tn IL C IL 0 U cz C2 a in E L CC CL > U Q. _J L' I C 0 L 0 ac . U = a. a CS _J =qN Li 0 (S-Jalaw) H1d30 Bethel Island Area Project PLATE k4K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 1 1 1-1956-01 CONE PENETROMETER NO. 3 B-4- V 0 ail H-1 d3a to to NN In V) Cft (D 1, ID :E— E - - - - - - - - - - - - - - - - in a.12 in z C .0 41 CP UA C3 N — x M 00. 0 — — — — — — — — — — — — — — — — H IL S" C3 f C2 CD 10 C3 C (Y r , o = . a 4, a • E La U a U > C2n Lit L < CD > U An 0 L Cr 0 L) It 0. 0 -Z r i ' � o (S-'D'4aw) H1d30 L Bethel Island Area Project PLATE k" K L E I N F E L D E R East Contra Costa County, CA CONE PENETROMETER NO. 4 B-5 PROJEcT No. 11-1956-01 (4004) Hid34 o to i 10 O 1^D N N cri '? f t3 1 I FW-W CL W 1 C2 m o E CD •+ O .. C CI o. u C Z y o Uf U.a — -- — — — — — — — — — — — — — 0 f to NO to C M CL to a W x , = x Ln� m � . IxCL C3 - - CL — — — — — — — — — — — — — — — — �H '" , m to � o m o 1 o k o to 1 N O _ 'Z N d to 6 La o c y tt ¢moo. N CL C U O •-' a C U o 41 C t C K v� o �^ Y W E ]C O t ca. L & to o U, a E3 t 4 � .. o IL > U O j L z v, - 1 O � 1 jo .+ 1 ., O J � 1 co c (s��1d1„) HIJ30 Bethel Island Area Project PLATE , K L E I N F E L D E R East Contra Costa County, CA CONE PENETROMETER NO. 5 B-6 , PROJECT NO. 11-1956-01 1 (10e.!) Hld30 to o to to CY co C) 0. 13 I ca 0 1 M W 0 tv C'.—._ —— ._ ._ ._ — — _. _. — _. _. — — —. —. — _. — — — — C31 La Q. Lm"a-C,-—— — — ., — — -- — — — — — — — _. — — — — — — — — ti C3 CL W, I Cm In C3 to 0 0 to 0 0 I CY 3: ID tl' 41 a 5 Z;'C' LL' a E Cr .t: tn C IL 0 Q co 1 > r C4 W < CD ca CL gL C3 > U C2 W) L C vi O a 0 0 4A z L 0 ex 0- a C3 I= C,- Q X CS (S-JalauJ) HIJ30 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PR 0.1 EcT NO. 11-1956--01 CONE PENETROMETER NO. 6 B-7 0 to 0 to to 0 to w O 'ti cc CL = C* QS"eUA= C6 m in Im a 1h 6 th f, — I O I w 4D U z — — — — — — — — — — — — in - tn ILL V C .0 92 sh in CL W noX H0 1 W I C3 0 IS, th 0 to 1N a (3 Co 41 v ,. 0 5 tn Is Ul. ,J CS 41 w mat- w C C2. L 4A (L U 10 . I fl I.- (L ca a > U flo VIA* C, 4h C3 L C tn- 41 L Q 5 C, H I d30 Bethel Island Area Project PLATE IK L E I N F E L D E R East Contra Costa County, CA CONE PENETROMETER NO. 7 B-8 mzoiEc*rN0. 11-1956-01 10 a to o 40 o C to to 10 CL Q I to -W U) C3 CD a W — I W. E 0 C' 7- L, '� r- V — — — — — — — — — — — — — — — — C .0 3 0 C2CY 0 th IL Lli 4n SL H In th oLh 1 C3 .n 92 0 W #n IN00 a V ' o a a cc IL C IL 0 a ;:S U > 43 C2 C Ir w 42 1h 2 E* x a < L co U 41 IL 13 1 a I.. CL j4 > U Lh L C in a 0 41 L 0 0- 0 0 1 4.3 0 ILS HicJ30 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. I 1-1956-01 CONE PENETROMETER NO. 8 1 B-9 (too:) to 0 to 0 U) 40 01 CIO to 0 Ln o N Ch 4n 0 1 in. CD E — — — — — — — — — — — — — — — — — — — — — in Cr mCL CL a Z I -CL.*1 O 0 a d) v1 O Let OA z I C2 41 CL in x cc CL — — — — — — — — — — — — — — — — — C" CL to (0, 0 RT gn zC $A m tn UC 0 9 U Ce > C Ix a w S x 11 1 < C L m o, 1 0 . ;J - I 1z tL > U C3 kh L C 0 !! C2 41 a .3 L 04� i a 0 00 o th (S-Jalaul) H1d30 Bethel Island Area Project PLATE k4K L E I N F E L D E R East Contra Costa County, CA PROJECT NO.. 11-1956-01 CONE PENETROMETER- NO. 9 B-10 toO to N N co) "I CL a O in Cm 0 1 wr W 13 — — — — — — — — — — — — — in cc, A a Cf e N 93 CL a 0 x a x - - - - - - - - - - - - - - - - - — H � _� O 10 14 UJ N o 0 go 0 0 h j In' CL dL U > ic UA C CD IL Ix H 0 0 > hF L C a a a L 0 to a L (9-JW45w) H1d30 Bethel Island Area Project PLATE K LEI N FE L D E R East Contra Costa County, CA PROJ I-C*I" NO. 1 1-1956-01 CONE PENETROMETER NO. 10 B-11 HJLd3(3 to w 0 0 to CO f f -cr C2 O.. CL th m _ ��o _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ._. 7 in m Z to .0 !!:, , 3 0 C2 24 - 11*0 to f i i 03 a — — — — — — — — — — — — — — — — LUCLcm iH Cb 1 oro in 00 LJ a. C U 0 9L 4,0 C3 C w a x E < 0 4C 4A O Ix I.- O L C 9L O t � r Ix (S-Ja-40w) HIJ30 r. Bethel Island Area Project PLATE KLEINFELDER East Contra Costa County, CA PROJECT NO, I I-1 956-01 CONE PENETROMETER NO. 1.1 B-12 ___ � In I CS � us OX fib cc CU Cm C CL Bethel Island Area Project PLATE K LEINF ELDER East Contra Costa County, CA CONE PENETROMETER NO. 12 B-13 PROJECT NO. 11-1956-01 ' - ' |� (10a;) Hid3u ' o "' q v t7 W d o o noh o i m m ,- ■ ' I= !� § ' 0 o0 o roti 16 .. .. t a . $ o. 0 x o r d H m do .. m cv o 0 0 W a « : on ►- • in W W ^ ^ • Y L � O a. 0 C 0 � o �$ O J �o 0 (sJe"}ow) H1d30 ^ Bethel Island Area Project PLATE I K L E I N F E L D E R East Contra Costa County, CA . I PROJECT NO. 11 196-01 CONE PENETROMETER NO. 13 B-14 = , I i ,o o to o to o to to a- �- N N t7 t0 17 er +a t ±�C 4 ^ W La c 1 U7 i 0O0 ' i p i m 0 CL CS Z Ci Cl O � G O ^ L v t 0a. W t 0 X 'W a. O cc cm H o {96 wn p i o vt o ^ p O tII � O O ! W LJ N q t w Q 1 mow. 1 U o °: a o t U ,w o oo n o w E i t ( O L w n � !u� t 4A CL o. . o . .o h a » L [ ( w ter.... ..._..T_..►�`.._....._� •+ 1 ( 0. o icy • a - o n o t t (S-Jelew) H1d30 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 CONE PENETROMETER NO. 14 5-15 1 1 1 1 1 i O to O m O b O to I 40 .- N N co c7 < 1 ! 1 1 La W W J.. • w cc 4 I i ! O a o p=a- m .. 1 t0 N t o N o t o m � m 1 • ! v O — — — — — — — — — — — O m 1 d o m 1 C d 1 7 0 i a o j In 1 o N in C2 L t i e N 1—�T_ �.— a a 1 W 0 C x 11 '^ ' O O I=-- S m ■ odo — — — — — — — — — — — — — — — — — — a. N ' m c � iLn 1 1 N { O = ID u O = i 0:o E , U tL G! 4: n O 1`1 1 C tC oo W 0 Y i -i N ! O V 1 I J 7 ~U J! o 4■ D ' ' ; 170 E. C N t O U 0 U 12 v i O J W 0 i 1 (s-1aaw) HSd3G Bethel Island Area Project rLa,rE k K L E I N F E L D E R East Contra Costa County, CA CONE PENETROMETER NO. 15 B-16 ' VROJEcr No. 1 1-1956-01 i ' (Iaa}) Hld3c 100 to 0 ID 0 to t0 O — N N to M qr W ti to • z 4 I - I -- O m o » o CO o » E C o d o _. — — — h w z 40. 90 Ln ` � L m W o I�w N w w tl x W 4 Q d w H 40 cain m w f � O Q Q O to N » t N � � 2 a !�� ,n IL CI cm i� u J ID � C � O ui -J o ' I- a- . o o_ o o JA > U . 5 4 0 o » o in O M L O w t! o u to CL o � .fit 4 (s-Jal aw) HI-d30 Bethel Island Area Project PLATE k1fl- 1K L E I N F E L D E R East Contra Costa County, CA i�jiam.C*r no. 11-195G-o1 � CONE PENETROMETER NO. 16 B--17 i T _i (4681) Hld3a I Ioa to o Ia o U) a to N 04 C% Co '7 It ! to-•� �� w In ! o N o O W � {{ K cam. C o ! p toy ; 1 p —Nr----r---t---�-- o - w IL pwp�� a x K N }cz w O.. — �J s ID i O o a I C2 n_ 11!! O 'D N tLL2ii.222 V !NI 4 . u ►.a ' Q I 1 i W i ap x o v I a M O ya. .pi is D - ap ... N C2 - .. 0 C !o N as a L o �or.CL a vFJ i1 C3 a "n r O N O ^ (s-Ja'}aw) Hld30 Bethel Island Area Project PLATE k4KLEINFELDER East Contra Costa County, CA PROJECT NO. 11-1956-01 CONE PENETROMETER NO. 17_ B-18 —._.._1 (1081) H1d3o t I ,o o 4o o 10 o �n o 10 w I r � N N M t7 � �f I O � I►W..W 4 O ao Cr O mco m I`� o — — — — — — — — Tom— — — O — — — Y Cf Z d o 10 '•� to r a 0 La _ C S d o — — .�= ._ — — — — — — — — — — — — — — ._ H ~ �CL Int m m a N 0 W (� u a 0 o E G m I '^ LUCL CO U 0 `►:a U 1 > � W I co N a w 0 .0..N 41 < u 4 L U I � a wa. d_ o • i > U O � O 1 L C C C3 1 N F Lu 9 7 O J ' v 1 !Li w I � r CD H1630 L_ Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA CONE PENETROMETER NO. 18 B-19 PROJECT .NO- 11-1956-01 + I 0800 H1d30 O b O i0 b N N O C) \ 8 ' w ILI O 1 O h O .. w 0 w O 1 w Lt Z g !► 7 d o e a . • _ o O N t H Ch Co O Ot N w O w = W A M • a`� O 7 t LL6 t n � o c W Y w � CL m a A •+ U 'ICL t • O > u C-3I L C M w � L O O J a� ' r u� (3JOIDW) H1d30 ■ Bethel Island Area Project PLATE k1l K L E I N F E L DER East Contra Costa County, CA ' CONE PENETROMETER NO. 19 B-20 PROJECT NO. 11-1956-01 S I E V E A N A L Y S I S H Y D R O M E T E R 3" 1.5" 3/4" 3/8" R4 #8 U16 #30. #SO #100 #200 see 90 lit I -I 80 7e Z 6e H U1 , N � 50 Z ul U Q: b 40 30 20 , 10 8 10 1 0.1 0.51 0.001 PARTICLE SIZE - mm ' GRAVEL SAND FINES coarse fine coarse medium tine I+ SYMBOL BORING DEPTH CLASSIFICATION ' O B-1 26.50 TAN SILTY SAND (SP-SM) ► i � 1 Bethel Island Area Project PLATE I K L E I N F E L D E R East Contra Costa County, CA GRAIN SIZE DISTRIBUTION C-2 PROJECT NO. 11-196-01 i S I E V E A N A L Y S 1 5 t H r 0 R 0 M E T E R 3" 1.5' 3/4" 3/8 #4 #8 #16 #38 #50 #100 *200 100 se ee oz60 07 se Z CL 40 30 20 SO 11 10 1 0.1 0.01 0.001 PARTICLE SIZE - mm GRAVEL SAND FINES coarse fine coarsemediummed! SYMBOL BORING DEPTH CLASSIFICATION 0 B-2 21.00 GRAY GREEN SILTY SAND (SP-SM) Bethel Island Area Project PLATE k K L E I N IF E L D E R East Contra Costa County, CA GRAIN SIZE DISTRIBUTION C-3 PROJECT NO. 11-1956-01 S I E V E A N A L Y 5 1 S H Y 3 R 0 M E T E S" 3/4" 3/8" #4 #8 #16 #30 #SO #LBO #200 90 SO *rO a z 60 M IL setiZ w w 40 IL :38 20 18 0 le 2 0.1 0.01 8.081 PARTICLE SIZE - mm GRAVEL -T -7 SAND FINES coarse -1 fine lccarsel medium f-i-, SYMBOL BORING DEPTH CLASSIFICATION 0 B-3 11.50 GRAY GREEN SILTY SAND (SP-SM) Bethel Island Area Project PLATE k" K L E I N IF E L D E R East Contra Costa Count y, CA GRAIN SIZE DISTRIBUTION C-4 PROJECT NO. 11-1956-01 S I E V E A N A L Y S I S M Y 0 R 0 M E T E R 3" 1.5" 3/4" 3/8" #4 #8 #iS #30 #60 #108 0209 90 80 Z 60 Se z lu w 40 IL 20 10 i0 2 0.1 PARTICLE SIZE mm GRAVEL SAND FINES coarse fine coarsemediummedium fine SYMBOL BORING DEPTH CLASSIFICATION 0 B-3 31.50 TAN GRAY SILTY SAND (SP-SM) Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 GRAIN SIZE DISTRIBUTION C-5 S I E V E A N A L Y S I S D R O M E T E R _ 3" 1.6" 3/4" 3/8" #d #B #16 #30 #68 #10@ #200 �i 1@0 90 8@ -r0 2 60 . H N N Q F- so !t) U 0: W 40 30 20 10 8 18 1 0.1 0.01 0.001 PARTICLE SIZE - mm GRAVEL SAND FINES enarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION 0 B-5 33.50 LIGHT BROWN SILTY SAND (SP-SM) Bethel Island Area Project PLATE K L E I N F E L D E R ' . East Contra Costa County, CA PROJECT NO. 11-I956-01 GRAIN SIZE DISTRIBUTION C-6 I E V E A N A L Y S I S H Y 0 R 0 M E T E R 1.5" 3/4" 3/8" #4 #8 #16 #30 #60 *100 *200 Lee 90 80 Ire Z 60 (n a. so z ul wa 1L 40 30 20 0 10 1 0.1 0.01 0.001 PARTICLE SIZE mm GRAVEL SAND FINES Icoarse I fine coarse medium,dium f i;'—� SYMBOL BORING DEPTH CLASSIFICATION B-6 7.50 GRAY TAN SILTY SAND (SP-SIM) Bethel Island Area Project PLATE kKLEINELDER East Contra Costa County, CA " IF PROJECT NO. 11-1956-01 GRAIN SIZE DISTRIBUTION . 1 S I E V E A N A L Y S I S H Y D R O M E T E R 3" 1.5" 3/4" 3/8" #4 #8 #16 #38 #50 #100 #208 10.0 i 9@ ee r Z 60 N N Q H 50 Z W EL V 4@ i 38 20 10 e 10 1 0.1 0.01 0,001 PARTICLE SIZE - mm GRAVEL SAND FINES coarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION B-7 11.50 GRAY BROWN SILTY SAND (SM) Bethel Island Area Project PLATE knK L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 GRAIN SIZE DISTRIBUTION C_g / S I E v E A N A L Y, 5 1 S H Y 0 R 0 M E T E R 3" 1.5" 3/4" 3/8" .*4 #8 #16 #30 050 #180 *200 100- 90-- 80 O z se So z 40 IL 30 28 1.0 10 1 0.1 0.01 0.001 PARTICLE SIZE mm GRAVEL SAND FINES coarse I fine coarsemediummedium I fine I SYMBOL BORING DEPTH CLASSIFICATION 0 B-7 16.00 GRAY BROWN SILTY SAND (SM) Bethel Island Area Project PLATE KLEINFELDER East Contra Costa County, CA - GRAIN SIZE DISTRIBUTION C-9 PROJECT NO. 11-1956-01 S I E v E A N A L Y S I S H Y 0 R 0 M E R I 1 1 1.5" 3/4" 3/6" #4 #8 #16 #30 #50 #100 #200 Ise 80 70 O Z So VI IL so z lu 40 IL 30 20 se Le 1 0.1 9.e1 8.081 PARTICLE SIZE mm GRAVEL SAND Fl NES coarse fine lCoarsel medium fine SYMBOL BORING DEPTH CLASSIFICATION 0 B-8 11.00 LIGHT BROWN SAND (SP) Bethel .Island Area Project PLATE k" KLEINFELDER East Contra Costa County. CA I GRAIN SIZE DISTRIBUTION C-10 PROJECT NO. 11-1956-01 S I E V E A N A L Y S I S H Y G R O M E T E R 3" 1.8". 3/4" 3/8" Ito *S *IS #30 *SO #100 0200 100 � 90 = 70 Z 80 tt N N Q F 50 z m U Q M 40 30 . 2e a 10 i 0 10 1 0.1 0.01 0.001 PARTICLE SIZE - mm GRAVEL SANG FINES coarse Tins coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION O B-9 11.00 GRAY SILTY SAND (SM) Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. II-1956-0I GRAIN SIZE DISTRIBUTION C-11 S I E V E A N A L Y S I SH Y D R 0 M E T E R 3" 1.5" 3/4" 3/8" *4 #8 itis #30 #So #100 tees ISO 90 80 ITS OZ 60 IL w w 40 :30 2 to Is PARTICLE SIZE mm GRAVEL SAND FINES coarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION 0 B-10 3.50 RUSTY BROWN SILTY SAND (SP-SM) Bethel Island Area Project PLATE K L E I N IF E L D E R East Contra Costa County, CA GRAIN SIZE DISTRIBUTION C-12 PROJECT NO. 11-1956-01 ' i S I E V E A N A L Y S I S HYDROMETE ,R — —� 3" 1.6"' 3/4" 3/8" *4 #8 #16 #30 050 #190 #209 lee 90 80 TO Z 60 Qi S Z 40 30 20 el I I 1 1-1 -11 111-1 le 1 0.1 0.01 18.001 PARTICLE SIZE mm GRAVEL SAND FINES Icoarse I fine coarsemediummedium fine SYMBOL BORING DEPTH CLASSIFICATION ❑ B-10 7.00 GRAY GREEN SILTY SAND (SP-SM) Bethel Island Area Project PLATE k K L E I N IF E L D E R East Contra Costa County, CA GRAIN SIZE DISTRIBUTION C-13 L PROJECT NO. 11-1956-01 S I E V E A N A L Y 5 1 S H Y 0 R 0 M E T E R ( D 1.5" 3;e4" 3/8" *4 48 *IS 430 *50 0100 #200 ISO. 90 80 Z SO in L 50w tta W 40 IL :30 20- 13 PARTICLE SIZE mm GRAVEL SANG FINES coarse finecoarse medium fine 1 SYMBOL BORING DEPTH CLASSIFICATION 0 B-12 3.00 BROWN SILTY SAND (SP-SM) Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA - I GRAIN SIZE DISTRIBUTION C-14 PROJECT NO. 11-19-56-01 F- S I E V E A N A L Y S I S H Y D R 0 M E ; E R 3' 1*5-3/4" 3/13" *4 08 *166 *38 058 *100 *200 le 9 s 70 o Z se to (C Z w 40 IL 30---- 29 10 All 1- PARTICLE SIZE mm GRAVEL SAND FINES coarse I fine icoarsel medium I iri., SYMBOL BORING DEPTH CLASSIFICATION 0 B-12 7.00 GRAY GREEN SILTY SAND (SM) Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 GRAIN SIZE DISTRIBUTION C-15 S I E v E A N A L Y S I S H Y D R 0 M E T E R 3% 1.5" 3/4" 3/8" *4 *8 816 *38 860 0108 8200 Lee So- 89 TO.- Z SO a. So— Z cu IL w 4 20-- 19 PARTICLE SIZE mm GRAVEL SAND FINES coarse I fine Icoarsel medium I fine SYMBOL BORING DEPTH CLASSIFICATION 0 B—12 11.50 GRAY GREEN SILTY CLAYEY SAND (SC) Bethel Island Area Project PLATE kn K L E I N IF E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 RAIN SIZE DISTRIBUTION C-16 1 - I S I E V E A N A L Y S I S H Y D R O M E T E R 3" 1.5" 3/4" 3/8" #4 08 #16 #30 #S0 #100 #200 100 se 80 -re ZZ 60 M N N Q IL � 50 Z W U Q: IL 40 30 20 10 e 10 1 0.1 0.01 0.001 PARTICLE SIZE - mm GRAVEL SAND FINES coarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION O B-13 6.50 GRAY GREEN SILTY SAND (SP-SM) Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA C-17 GRAIN SIZE DISTRIBUTION PROJECT NO. 11-1956-01 I S I E V E A N A L Y S I S H Y G R O M E T E R 3" 1.6" 3/4" 3/8" 84 #8 #16 #30 *60 #160 *200 100 a 90 se -re o Z s0 M ' N N Q a SO Z w U Q: EL 40 30 20 10 0 IL 10 1 0.1 0.01 0.001 PARTICLE SIZE - mm GRAVEL SAND FINES coarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION ❑ B-13 21.50 GRAY GREEN SILTY SAND (SP-SM) Bethel Island Area Project PLATE K L E I NFELDER East Contra Costa County, CA PROJECT NO. 11-1956-01 GRAIN SIZE DISTRIBUTION C-18 a _1: C .. APPENDIX D METHODS OF MITIGATION OF POTENTIALLY LIQUEFIABLE SOILS This section of the report outlines several ground modification techniques that may be used primarily to mitigate liquefaction or 1 the effects of liquefaction. These are: 1. Dynamic Deep compaction. 2. Vibrocompaction and Vibroreplacement. 3. Soil Mixing. 4. Pile Foundations. 5. Slurry wall cutoff and permanent site dewatering. The above ground modification alternatives are discussed briefly in the following paragraphs. Several contractors were contacted and have provided rough estimates of the anticipated unit costs for performing these services. The anticipated relative effectiveness, difficulties and estimated construction schedule based on our and the contractor's experience for each of the alternatives are also discussed. 1. Dynamic Deep Compaction Dynamic deep compaction consists of a large crane dropping a weight in freefall. Weights generally range from 15 to 30 tons and are constructed of box-steel and concrete, sheet-steel or mass reinforced concrete. The purpose of dynamic deep compaction is to increase the relative density of granular soils containing less than 20 percent fines. The treatment is achieved by performing a series of heavy tamping passes to provide improvement to the soil base layers. These drops are generally wide spaced and are performed with a heavier weight. Subsequent to these, a series of closer spaced, lighter weight drops are made to improve the shallower layers. For this project, use of a lighter weight may be appropriate throughout the improvement process. The use of dynamic compaction on soils containing higher percentages of silt and clay must be phased since there must be time to allow pore water pressures that have built up to dissipate. At the site, fines contents are generally below about 15 percent and pore water pressure dissipation should occur rather rapidly. Further, larger areas aid in providing continuity to the project and reduces costly down time. We have discussed the soil conditions encountered with representatives of GKN-Hayward Baker and Geo-Con, Inc. , specialty contractors in ground modification and site improvement. Based on preliminary discussions, we were informed that the cost of this method would range from $0.60 to $0.80 per square ft. This does not include backfilling of the depressions nor follow up testing and monitoring to evaluate the improvement. We were informed that this typically costs an additional $0.20 to $0.40 per square ft. Therefore, total costs for this method of improvement may range from $0.80 to $1.20 per square ft. Maximum anticipated costs for this method are estimated to be $1.50 per square ft. Please note that these values are rough estimates and the actual cost may vary according to the abundance of fill material at the site and the size of the area that is to be improved. Large vibrations produced due to the dropping of the weight could affect adjacent structures, buildings and the existing levee. According to recent measurements, peak particle velocities of 1.5 in/sec at 100 ft. , and 0.4 in/sec at 200 ft. are common. our concerns deal with shaking the existing levee and possibly -- 4 ' ■ 41 „ ] c a a � � 3 a i41 41 a M CL e o L c u a c fi 3 w L ■ c (Continued from previous plate) ■ -4 LaU 00 0 si a ■ ■ O N m OU SUX U N a+ O F a SAND (SW) - dense, well-graded, est. 5% fines 80 85 94/ -#200=5% 4" 90 SILTY SAND (SM) - blue-gray, fine sand, saturated 95 i 100 - very silty below 100 ft 105 110 58 115 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-1 A-4 PROJECT NO. 11-1956-01 I t ' D ■ u i ]C : a +' j 11 3 0 la n L i L C L • a E 0 3 C � —+ C E L i.. L M C n s -+ L o 0 0 0 0 s+ 0 ++ • • Continued from previous late o 0 m o0 six U u» 0 a ( P plate) D 120 SILTY CLAY (CH) - blue-gray, high plasticity, wet 125 SILTY SAND (SM) - very dense, blue-gray, fine sand, saturated, lots of pyrite 98 130- 135 140- 145 40 145 150- 155 D Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-1 A-5 PROJECT NO. 11-1956-01 Mo6i:"ied Cali n i 2 Samn1 p r� Date Completed: 9i16188 ^.0 m. €.II. Sou* Acari aar; Logged By Larry Goldfarb - 2.0 in. Q.D. I.4 in. I.D. Total Depth: 54.5 ft Hammer We 140 lbs. FIELD LABORATORY w ,, r DESCRIPTION w d 41 3 C O , y u 3 R 8� II sNi M E a 31cU -+ c E i w t w C a vNi -4 a a ° 0 v x a 4J as o � a Surface Elevation: Approximately -6 ft TOPSOIL 12 1.5 CLAYEY SILT (ML) - stiff, dark brown, low to medium plasticity, very moist to slightly wet, iron stained, roots 6 VERY SILTY SAND (SM) - loose, brown, 5 fine to medium sand, wet 20 -#200=24% - silty at 5 ft - medium dense, silty below.7 ft 10 14 -#200=22% 24 15 - slightly silty below 14 ft 20 57 -#4=100% - very dense below 20 ft -#200=7% 25 30- 86 35 Bethel island Area Project PLATE K L E I N F E L D E R East Contra Costao C unty, CA PROJECT Na, 11-1956-01 LOG OF BORING NO. B-2 I A-6 i c M V M Q. E a :1 C %- -i C E L t- .0 M C V) oan m o a s UX v 41 U) V a tr- a (Continued from previous plate) - increase in silt content at 37 ft 40- 45 50— lid SILTY CLAY (CH) - very hard, tight brown, high plasticity, slightly wet 65 TV=1.2 tsf. 3.2 55 60- 65 70- 75 Bethel Island Area Project PLATE kn K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-2 A-7 PROJECT NO. 11-1956-01 2.0 in. 1.D. S:zndar(i Sr)ht Spoor, Sampler I 4 - 2.0 in. O.D. 1.4 in. I.D. Logged By: Larry Goldfarb Total Depth: 54.5 ft Hammer Wt: 140 lbs. FIELD LABORATORY DESCRIPTION 4E L 4J 4113 M 0 ♦ 3 c O ala. E 0. 0 -«1 C E L 4. L 0 c • 4 • Surface Elevation: Approximately 0 ft o m m Emx n N a ►- a SILTY SAND (SM) - very dense, brown, 59 fine sand, no cementation, dry, some iron staining - well cemented at 2.5 ft 5N 61 - fine to medium grained, very moist - dense from 6 to 20 ft 44 - slightly wet at 8.5 ft 10 43 -#4=100% - gray, saturated below 10 ft -#200=6% - slightly silty below 10.5 ft 15 39 20- 61 -#200=6010 - dense to very dense below 20 ft 25 30-- 47 -#4=100% - medium grained sand below 30 ft -#200=10% 35 Bethel Island Area Project PLATE K L E l N F E L D E R East Contra Costa County, CA (_PROJECT NO. 11-1956-01 LOG OF BORING NO. B-3 A-8 F:FLD LABORATORY Int w � 4 a 3L a R r v c • ,r, -' a w i41 a e i 4 -lei, L i o 0 0 0 Z. N 4 l (Continued from previous plate) c N m oo Eox o N V o a 40 - sandy silt layer from 42.5 to 43.5 ft 45 SILTY CLAY (CH) - hard, brown, high 50 plasticity, slightly wet 62 104 25 2.5 3.2 55 60- 65 70 75 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-196-01 LOG OF BORING NO. B-3 A-9 • Jr. �. 1 '(��. Wil' - - Date Completed: 9/1 2.0 -- Logged r Logged By: Meleah Ashford L•0 in Q.D. ' Sheibv Tune Samoler - 2.8 in. dia. Total Depth: 74.5 ft Hammer We 140 lbs. FIELD LABORATORY DESCRIPTION a L tIL aA -i 3 a a 4 a O r a - 4i Lr0 00 OI M +� m m o N m 00 E 0 x v w .0 o a Surface Elevation: Approximately -6 ft SANDY CLAY (CL) - stiff, brown, low plasticity, moist 16 117 18 1.2 3.0 5 22 SILTY SAND (SM) - medium dense, gray, fine to medium grained, saturated, some -#200=2096 comented nodules SAND (SP) - dense to very dense, gray, fine 10 36 grained, saturated 83 15 75 -#200=8% 20 - slightly silty at 19 ft SANDY CLAY (CL) - hard, gray, low plasticity, moist 25 SAND (SP) - very dense, brown/gray, fine to medium grained, saturated �. 30- 86 35 Bethel Island Area Project PLATE " K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 LOG OF BORING NO. B-4 A-10 FIELD 1 Af30RATORY 1 DESCRIPTION 3 M Mar+ 0 a � y , d E 0 a C 4- «1 C E L i. C M C a a -a L a a a 0 a a+ a ++ a • us rev ont Cinued from previous 0 0 m 00 EUX n 0 V o F L ( P plate) 40 68J 10" 45 �4 SILTY CLAY (CL) - hard, brown and gray, 50 low plasticity, moist 55 2.0 55 y 60- 65 3.7 3.0 97 30 70 SAND (SP) - very dense, brown, fine to 83� medium grained, saturated 75 Bethel Island Area Project PLATE KLEINFELDER East Contra Costa County, CA PROJECT NLOG OF BORING NO. B-4 A-11 O. 11-1956-01 �' 0.5 47 .411 1 1 1 VJ 0 2 A I ha: CL C 0.3- V CP .0 •C a o 0.39 0 - CL 2 a=0.2g Cr a) E 0.1 - 0 . f 0 101.214 16 i8 20 30 40 Modified Penetration Resistance, NI—blows/ft Chart for evaluation of liquefaction potential of sands for earthquakes of different magnitudes. Source: Seed and ldriss (1982). Bethel Island Area Project PLATE E R 'nst Contra Costa County, CA A U E F CTION POTE';""—.' ��: •►��\\\��"tic c. ;fd:ria.+►�s"i tif,._;,;,,�-rl;;�; . �• mow'..� !It .�'►�` t e:;{ tltp �. 4' •!rf a'�s� '.+lt�r' Z1,�1�1,1~it.^{4��'�`���il � �t�1.1�M I�. 6i' �_ rla1= a i1iYHlt��- • f s • �a�r_ I bar_ 100 kPa M 1.02 kg/cm2--1 tst ► 10DD 10 12 11 Q1 9 L D10a v M ONE A 5 L 5 0 G 4 0 10 3 t 0 U �.. 1 2 1 0 1 z s 4 s e e Friction Ratio C%) Zone Soil Behaviour Type Qc/N 1) Sensitive fine grained 2 2) Organic material 1 3) Clay 1 4) silty clay to clay 1.5 5) Clayey silt to silty clay 2 6) Sandy silt to clayey silt 2.5 7) Silty sand to sandy silt 3 .8) Sand to silty sand 4 9) Sand 5 10) Gravelly sand to sand 6 11) very stiff fine grained (*) 1 12) Sand to clayey sand (*) 2 _ * Overconsolidated or cemented UBC Simplified Soil Behaviour Type Chart for Standard Electronic Friction Cone Showing Proposed Zone of Potentially Liquefiable i Soils (After Robertson and Campanella, 1983) Bethel Island Area Project PLATE KLEINFELDER East Contra Costa County, CA I CONE SOIL BEHAVIOR CHART 7 PROJECT NO. 11-1956-01 � ' SACRAMENTO 20 km a 0-1 N O S 10 km 1 P 40 AN _ � •:�=_:__ J,M is.: 'i2�?i �O� ,STOCKTOM PROJECT SITE >. A 5 bCALIFORH4 AWEOUCT --_ c r DELTA PUMPING PLANT (DwR) � wwreu 1 ED TRACY PUMPIN}C/' PLANT(USER) —flELTA-MENDOTA CANAL .� Map sho`-ing maximum amount of subsidence on individual islands(based on an interpretation of USGS topographic quadrangle maps). Maximum subsidence: 1)less 1.5 m;2) 1.6 to 3 m;3)3.1 to 4.5 rr;4)4.6 to 6 m; S)over 6 m;6)not reclaimed, permanently flooded islands.(excluding purposely flooded Clifton Court Forebay of the SWP),and 7)generalized"0"elevation contour. Source: Prokopovich - (1985) I Bethel Island Area Project PLATE k K L E INFELDER East Contra Costa County, CA DELTA SUBSIDENCE 8 PROJECT NO. 11-1956-01 Cafiforni? Samr.k.. Date Completed: 9,1!9,18 8 :.0 in. I.D.. - Standard S fit Sr)o,,)-. Sarnpier Logged By: Meleah Ashford 2.0 in. O.D. 1.4 in. I.D. Total Depth: 60.0 ft Hammer Wt: 140 lbs. FIELD LABORATORY 41 DESCRIPTION w 7t L V a AJ a C V N 01 .61 .4 41 a L C L 6 41 a 3 0 a 41 M 0 a M E 9) 31 c I$_ -4 C E L It- z 0 C 4 -4 L 8 U 0 0 o 41 a aN Surface Elevation: Approximately -4 ft M C2 0 n. X:a X U (a 46J 40J SILTY SAND (SM) - loose, brown, fine-grained, dry to moist 7 SANDY CLAY (CL) - stiff, brown, with 5 N 10 some organics, moist -#200=33% 10 23 -#200=44% VERY SILTY SAND ( SM) - medium dense, brown, fine grained, saturated 15 32 decreased silt content at 15 ft 20 SANDY CLAY (CL) - very stiff, brown, moist 9" i SAND (SP) - very dense, brown, 25 fine-grained, saturated 30- 78 #4=100% --200=9% - slightly silty at 33 ft 35 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-5 A-12 PROJECT NO. 11-1956-01 LABORATORY tit c D SCRi Ts -moi � i L c t. r CL e o L .-� t r U c t t r (Continued from previous plate) r' r 0 0 0 0 0 0 0 +� 0 M +J r M IL 40- 73/ l 12° 45 50 55 72 CLAY (CH) - hard, brown, most _ 60 .� 65 70- 75 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-5 A-13 PROJECT NO. l 1-196-01 ,� Sampler: Modified California Sampler - 2-5 in.-O.D. Date Compieted: 9/19/88 2.0 in. I.D., Standard Sr)lit Sin-),.in Sampler Logged By: Meleah Ashford - 2.0 in. O.D. 1.4 in. I.D. Shelbv Tube 0 Sartioler - 2.8 in. dia. Total Depth: 65.0 ft Hammer Wt:- 140 lbs. FIELD LABORATORY DESCRIPTION 4J a 3 L 4J Z 4J L C L 0 41 CL .3 .0 u. E 0 31 PC 4- .04 C CEL Le 4. Z11 a C 0 4 -4 a L N U 0 a 0 0)4J 4J 8 -0 0 0 6 Surface Elevation: Approximately -3 ft M M IL r. 0 SILTY SAND (SM) - dark brown, dry 25 1.5 3,5 SANDY CLAY (CL) - very stiff, brown, fine-grained sand, moist 5 - SAND (SP) - medium dense, brown, fine grained, saturated 15 -#4=99% -#200=11% slighty silty below 6.5 ft 10- 31 -#200=8% 15 20- 35 SANDY CLAY (CL) - brown, fine grained sand 25 SAND (SP) - very dense, brown, fine grained, saturated 30- 73/ 12" 35 Bethel Island Area Project PLATE KLEIN F ELDER East Contra Costa County, CA LOG OF BORING NO. B-6 A-14 PROD ECT NO. 11-1956-01 FlY C + 3 +�+ 3 M. *--1 O. r 0. E 0 3 C r- •-4 C E L 4 L ■ C Y 0 a L r u 0 0 0 V ■ ++ Continued from previous late o N m oo E�x o N 4+ o a ( P plate) 40 88/ 9" 45 50 if 55 SILTY CLAY (CL) - hard, brown and gray, if 4.5+ saturated - some silty seams 60 - silt seam 61 to 61.5 ft 65 70- 75 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-6 A-15 ' PROJECT NO. 11-1956-01 _. — Date %o:: :=:`- - 2.4 in i.D.. Standarr� Solis Snoonj,Samaier ' - 2.0 in. O.D. 1.4 in. I.D. Logged By: Tim Huntting Total Depth: 66.5 ft Hammer Wt: 140 lbs. FIELD LABORATORY DESCRIPTION u 3 Lc i o ,t 3 a 0 41 a 0 0 .N ° 0 L c'` a c s L `` 1 a e Surface Elevation: Approximately -6 ft d q ..� L 11 0 0 0 0 +� M �+ � d 0 N G2 0 0 E a V N +i O k- 4 SANDY SILT (ML) - soft to firm, dark brown to black, fine grained sand, dry 21 108 19 1.5 1.0 SANDY CLAY (CL) -very stiff, mottled 5 gray, dark brown, orange and tan, trace fine gravel, moist 35 2.2 LL = 40 PI = 22 _ wet at 7 ft - blue-gray at 8 ft 10 12 SILTY SAND (SM) - medium dense, blue-gray, fine to medium sand, saturated 15 37 -#4=100% SILTY SAND (SM) - dense, gray brown, fine -#200=24% to medium sand, saturated 20 - very dense, brown, increased silt below 55 20 ft 25 - Iight brown tense of clayey sand at 25 ft 30- 75 35 Bethel Island Area Project PLATE KLEIN FELDER East Contra Costa County, CA LOG OF BORING NO. B-7 A-16 �' PROJECT NO. 11-1956-01 LABOF TORY w +yu x N t 4 DES-CRIPTION 4 a i 4Jx 41 x 41 -CL 4 3 x 4j M M C. 0 .11 C. E C aC4 -i C E L 4 t x C L xu o o a 4J x 41 x • Continued from revious late a N m as E�X o N j o a ( P P SILTY SAND (SM) - continued 40 94/ 10" - intermittent lenses of silty and clayey 45 sand below 45 ft 50 SILTY CLAY (CL) - hard, olive brown mottled w/orange and light tan silt, trace 55 concretion, trace fine to medium sand, 39 2.5 saturated 4.0 60- 65 $2/. SILTY SAND (SM) - very dense, brown and " blue-gray , 70- 75 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-7 A-17 PROJECT NO. 11-1956-01 Date Completed: 9/2C° :t <• Logged By: Tim HunttinQ Total Depth: 61.0 ft Hammer Wt: 140 lbs. FIELD LABORATORY DESCRIPTION 3 L 41 41 � a � am u NioM . aooim 0a41 41i w-+ a n Surface Elevation: Approximately -7 7 ftn (4 mnn xnx a to a o r a SANDY CLAY (CL) - firm, dark brown, dry 13 CLAYEY SAND (SC) - stiff, dark brown, gray and orange mixed, medium plasticity, 5 moist 17 96 29 1.3 SANDY CLAY (CL) - stiff to very stiff, brown and blue gray, low to medium plasticity, fine sand, moist SAND (SP) - dense, blue gray, fine to 10 medium grained, saturated 39 -#4=100% -#200=4% 15 20 SANDY CLAY (CL) - light brown, low L F,5�, plasticity, fine sand 75 SAND (SP) - very dense, blue gray and brown w/trace of orange, fine to medium 25 sand, saturated 30- 35 Bethel Island Area Project PLATE Ink K L E i N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-8 A-18 j Pu�JECT NO. 11-i9�6-01 r :1F..4TORY a M r 41 ] C r a C 41 �2 3 M e� n r 4J • CLE o a c w a c E L �. L " c (Continued from previous plate) L r u o 0 o ■ .J r r ar . con M m co s 0 ix � N ++ o � a 40 SANDY CLAY (CL) - light brown, low plasticity 45 68 SAND (SP) - dense, brown, fine to medium grained, some silt, saturated 50 SANDY CLAY (CH) - light brown, trace 55 fine sand, medium to high plasticity 60 SAND (SP) - brown, fine to medium grained, saturated 65 70- 75 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-8 A-19 PROJECT NO. 11-1956-01 i t Sampler. Moaified California Sa:gpier - 2.5 in. O.D. Date Completed: 9/20/88 2.0 in I D. Standards::: Spoon Sampler ' - 2.0 in. O.D. 1.4 in. T.D. Logged By. Tim Hunttina Total Depth: 67.5 ft Hammer Wt: 140 lbs. ' FIELD LABORATORY DESCRIPTION 3c i a ' a 91 e o L c w c E r w t 41c L 00 0 �+ Surface Elevation: Approximately -6 ft r ■ -+ � r r 0 N m oo a X:UX o m SILTY SANDY CLAY (CL) - firm, dark brown, dry 32 98 27 1.2 1,5 - very stiff, moist below 2 ft - stiff, blue gray, orange and brown, low ' 5 plasticity, fine to medum sand below 3 ft 15 - increased silt, firm, some concretions, light blue gray below 6 ft ' 10-- N 18 -#4=10096 -#200=18% SILTY SAND (SM) - medium dense, blue gray w/trace orange and brown, fine to medium sand, trace silt, moist 15 38 - dense below 15 ft ' 20 1 - 25 - sandy clay layer between 24 to 24.5 ft 77/ - very dense below 25 ft ' 12" 30 35 _ Bethel Island Area Project PLATE ' KLEINFELDER East Contra Costa County, CA LOG OF BORING NO. B-9 A-20 PROJECT NO. 11-1956-01 'rIA i LABORATOrY I DESCRIPTION \ 3 L C AJ • C. E 0 3 C 4 -1 01 C E L t. t r C r r .1 L r o o a o ++ r ++ r Continued from previous late o IA m oC1 EUX U 0 y o r SOL ( P plate) 40- 45 �. 55 50 SILTY CLAY (CL) - hard, olive brown and tan w/some orange, some fine sand 55 642 3.0 - clayey sand lease between 55.5 and 56 ft - lease of sandy clay/clayey sand, very , dense, brown and rust 60- 65 0 65 70 75 .. Bethel Island Area Project PLATE k" K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 LOG OF BORING NO. B-9 A-21 SGZ^`+:n },i-.ri:=jorj L.F.:=i;i-::i�•l:,,L�jat - _ _ 4f t: Compjet-d: ;,'21_ /$8 2 - _ i_ _ - -- .0 in i7. Siarid^ Spik Logged By: Tim Hunttingz 2.0 in. O.D. 1.4 in. I.D. Total Depth: 56.5 ft Hammer Wt: 140 lbs. ' FIELD LABORATORY DESCRIPTION v \ 4J 3 c O w CL Q £ a 3t C i- .' C S i t►- r if C o yr m a`o u .E a 0 W sui o tr- a Surface Elevation: Approximately -6 ft SANDY SILT (ML) - dark brown, dry SILTY SAND (SM) - loose, brown to dark brown and orange, fine to medium grained, 5 dry to moist 4 -#4=100% - blue gray with little grassy fibers, -#200=10% saturated below 6 ft - slightly silty at 7 ft - medium dense below 8 ft IO 16 -#200=12% - trace concretions below 11 ft i 15 48 - dense, gray to brown below 15 ft 20- 84 - very dense below 20 ft 25 30- 35 Bethel Island Area Project PLATE K LEI NFE LDER East Contra Costa County, CA ? i t LOG OF BORING NO. B-10 A-22 I PROJECT NO, 11-1956-01 I 1 FIELD. ! T._ .. "'.'lay ■ i a r 4 DESCRIPTION , ■ ■ 3 c a 01 ++ -4IJ 4J 0 L C L ■ a OI Lr ■- 0 00 0 V ■ ■ ■ o N m 0 oIL E U X V v► V 0 a (Continued from previous plate) , r 40 78/ - light brown at 40 ft Ir ' 45 - increased clay content below 46 ft SANDY CLAY (CL) - hard, olive and light 50 tan, some silt and brown and orange sand ' 78 4.2 SANDY SILT (ML) - medium dense, 55 medium brown w/orange multicoloring 18 60- 65 0 65 , J 1 70- 75 , Bethel Island Area Project PLATE KLEINFELDER East Contra Costa County, CA LOG OF BORING NO. B-10 A-23 ' PROJECT NO. I1-1956-01 Scamnler - 2.5 is O.D. Completed: 9 1 '18S Logged By. Tim Huntting 2.0 in. C.::. -4 in. I.D. Total Depth: 70.0 ft Hammer Wt- 140 lbs. FIELD LABORATORY DESCRIPTION ra- 41 a ; z w k.- 3 L 41 r Aj 0 \ 41 3 C a -4 a 0 4j Aj 3 a -4 " a CL a L 9 CL r CL 6 D 3 c -4 L 0 Q -4 Lou (30 C a E 41 0 Aj a 0 U) M 00 Z U X a 0 41 0 IL Surface Elevation: Approximately 7 ft M SILTY SAND (SM) - very dense, gray, fine to medium grained, dry 53 orangish brown below 2.5 ft 5 29 medium dense, wet, 6 to 15 ft 10- 26 15 36 dense below 15 ft 20— 'S45 medium brown, multicolored below 20 ft 25 sandy silt layer 27 to 28 ft 30- 35 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-11 A-24 PROJECT NO. 1 1-1956-01 •- a i iJ A N M Uk Z r 41 a --4 .N i L CC L 0 4J CL M E a a1 C 4 . C E L 4. .0 M C n m p a °� n°x col 041 o H M (Continued from previous plate) 40 78/ - very dense, blue gray below 40 ft 12" 45 50- 55 0 SS SANDY SILTY CLAY (CH) - hard, olive brown w/dark brown and orange, blue gray and light tan mottling, medium to high plasticity, little concretions, moist to wet 60 58 3.5 65 70 75 Bethel Island Area Project PLATE i K LEINFELDER East Contra Costa County, CA ■ PROJECT NO. I1-1956-0I LOG OF BORING NO. B-11 A-25 Date Completed: 9/21/88 2.0 in. I.D., +Standard Sr,!i- Spcnor: - --,pier Logged By Tim Hunttina - 2.0 in. O.D. 1.4 in. I.D. Total Depth: 56.5 ft Hammer Wt: 140 lbs. FIELD LABORATORY ,, p t DESCRIPTION fF J M � 3 0 0,0 0. r O 4 o0 e o L c U a c e L w t " c Surface Elevation: Approximately 7 ft (0 m ca u FUx v 4J 0 0) 4J o r L PP Y - ' SELTY SAND (SM) - medium dense, gray, fine to medium grained, dry 15 _#20010 - orange grading to light brown, dry to moist - slighty silty at 3 ft 5 15 -#4=100% - blue to dark gray, wet, trace concretion ' -#200=15% 10- 7 - very silty, loose, 10 to 15 ft 15 69 - very dense below 15 ft 20 86/ 12" 1 ' 25 - brown below 26 ft 30-- 'N55 J J) 35 i Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-196-01 LOG OF BORING NO. B-12 A-26 1 OR!' 4JDESk" N • 41 C -4 4J 8 L 41 a 3 0 010 CL a CL E a :3 C - c F C L 0 u 0 a a 4J a 41 8 previous plate) 'M A M 0 X 0 U) 4, 0 L (Continued from - increased clay content below 36 ft SANDY SILTY CLAY (CL) - hard, olive 89/ brown to tan, moist 12" 40 45 89/ layers of sandy clay and clayey sand below 10" 45 ft 50 SANDY CLAY (CL) - blue-gray, medium plasticity, fine to medium sand 55 N 51 CLAYEY SILT (ML) - very stiff, greenish brown, very fine sand, moist 60- 65 - 70- 75 Bethel Island Area Project PLATE K L E I N F E L D. E R East Contra Costa County, CA LOG OF BORING NO. B-12 A-27 PROJECT NO. 11-1956-01 Snm-Ier - _ _ in. 0.- Date Compictca9.,-^i/8L _ _ - _award S) Logged B Tim HunttinR - 2.0 in. .7. 1.4 in. I.D. gg Y� Total Depth: 61.5 ft Hammer Wt: 140 lbs. ' FIELD LABORATORY DESCRIPTION w a L yJ � hM -4 Ai 4'0 L C L E ' a a C t- -a C-IJE 0. E L w C 0 C I n -+ L • 0 0 0 0 &J a ++ ■ ■ Surface Elevation: Approximately -8 ft G N m CIG EU\ U N 0 H d SILTY SAND (SM) - medium dense, brown ' and orange, medium to fine sand, moist 12 - wet below 2 ft 5 15 -#4=100° ts -#200=9% - slightly silty at 6 ft 10 15 - very silty 9 to 11 ft 1 - very dense below 13 ft 55 15 ' I 1 ' 20- 92 -#4=100% -#200=8% - slightly silty at 21 ft 25 30- 62 ' 35 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA LOG OF BORING NO. B-13 A-28 PROJECT N'O. 11-1956-01 i FIELD LABORATORY 4J 3♦. a L.c tR .N • ri �L 3 41 as s s. 4 M E O 7 C w . C E L r- C r C a 41 0 4J a N M D O U s U\ U 01 +i o FE- a (Continued from previous plate) SILTY CLAY (CH) - hard, light brown medium to high plasticity, wet 40 38 2.7 45 50 CLAYEY SILT (ML) - very stiff, brown, medium plasticity, some pyrite, wet 55 60 31 65 70- 75 75 Bethel Island Area Project PLATE lk" K L E IN F E LD E R East Contra Costa County, CA PROSECT NO. 11-1956-01 LOG OF BORING NO. B-13 A-29' z orn p;e 1-_--C- Logged By: Larry Goldfarb Total Depth: 15.0 ft Hammer Wt: Wet Rotary FIELD LABORATORY DESCRIPTION 3C 0 X -4 It8 L C L a a 3 -a EL a a AJ 4. z L 0 U 0 0 c BE 41 a AJ • a C 0 M 00 a EUX 0 U) 41 0 M Surface Elevation: Approximately 4 ft SILTY SAND (SM) - medium dense, brown, Log of orange sand, moist Boring medium to fine sand, wet 5 10 very silty from 9 to 11 ft Piezometer Backfill very dense below 13 ft Ji 15 20- 25 30 35 A I I Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-11956-01 LOG OF BORING NO. P-1 A-30' Date Cornn'seted: 9/2-7/010c, Logged By: Larry Goldfarb Total Depth: 15.0 ft Hammer Wt: Wet Rotary FIELD LABORATORY 41 ; r- DESCRIPTION 4-- 3 Ll Ai 0 41 8 41 3 C a 0 dJ 4- --4 C E L 46. C 9 X AJ a L C L 0 4J IL 3 CL a .0 n. E 13 3 C 0 4, 8 C 4 L a U 0 a a IJ 0 4J 0 Surface Elevation: Approximately -2 ft M 13 13 Q Z 0 X 0 0 -J 0 SILTY SAND (SM) - dark brown, fine to Log of medium sand, dry Boring slightly moist, gray brown below 3 ft 5 10 - some cementation to 10 ft Piezometer - very silty below 10 ft Backfill 15 20 -'— 25 30- 35 - Bethel Island Area Project PLATE Ink K L E I N F ELDER East Contra Costa County, CA LOG OF BORING NO. P-.2 A-31 PROJECT NO. 11-1956-01 5. =:er- Logged By: Larry Goldfarb Total Depth: 15.0 ft Hammer We Wet Rotary . FIELD LABORATORY DESCRIPTION L E \ 4J ]C a O 4J 12 3 M 041 d r ■ ++ 4. E a 7Cu . C E Go r°n m o o u r coy x a ai ° o FE- a. Surface Elevation: Approximately -1 ft SILTY CLAY (CL) - dark brown, medium ' Log of plasticity, moist, some coarse sand Boring - mottled gray below 2 ft 5 SILTY SAND (SM) - brown, medium sand, saturated l0 - gray, decreased silt content below 9 ft rPiezometer Backfill 15 ' 20- 25 0 25 30 35 Bethel Island Area Project. I PLATE K L E I N F E L D E R East Contra Costa County, CA ' LOG OF BORING NO. P-3 j A-32 PROJECT NO. 11-1956-01 i �ar.:pler• I , Date -- Logged By: Larry Goldfarb , Total Depth: 15.0 ft Hammer Wt: Wet Rotary FIELD LABORATORY , u r DESCRIPTION 12 3 0 a4J La i i 4 d 4 LL •0 0 0 O +i M o N m o o s o x o N .+ o a Surface Elevation: Approximately -7 ft SILTY SAND (SM) - dark brown, fine to Log of medium sand, moist Boring - brown, very moist to slightly wet below 3 ft 5 - gray, decreased silt content below 7 ft 10 Piezometer Backfill 15 20- 25 0 25 30- 35 Bethel Island Area Project PLATE K L E. I N F E L D E R East Contra Costa County, CA , LOG OF BORING NO. P-4 A-33- PROJECT NO. 11-1956-01 i /� 0 N� 0 Y r,�11`1'f Tp 'Poll' 0 FSE.'t fl 0 1 _20 . t _50 �Ooo 6000 ' SQQO g000 Oct P4AZE .80 3QQQ p25�a�,�E. t 2flfl0 a Pt°ject GA l000 na pre county. .90 fl Bette` Is v costa �(�1'E`�'C 510 East c PVONG QROf �. Y-. IE 11..195b_Q1 �10>�C? Nps POINT TO POINT PROFILE LINE DINT B-13 B-11 B-10 B-1 B-8 SET 0 0 0 0 0 20 , 0- -20- -40- -60- -20-40-60 -80- -100- -120- 1401 80-100-120140 i 0 2000 4000 6000 8000 DISTANCE, feet Bethel Island Area Project PLATE , KLEINFELDER East Contra Costa County, CA 2-D PROFILE ALONG EAST SIDE A-35 OJECT NO. 11-1956-01 POINT TO POINT PROFILE LINE ,INT B-13 B-2 B-9 B-7 FSET 0 0 0 0 0 - -10 -2a -30 i . -40 i -50 - 60- -70- - -sa 0 1000 2000 3000 4000 5000 6000 7000 DISTANCE, feet Bethel Island Area Project PLATE JMq KLEINFELDER East Contra Costa County, CA :;OJECT NO. 11-1456-0I 2-13 PROFILE ALONG CENTERLINE A-36' 13A B-B_' 1 B_2 B"5 0 4 0 B- a _1 . FtLBLINE la-4 a � B1Q TD PtNT vols B-3 a IN,r 'B- a-13 a ' 0 4 4gSE'T 24 s a _20 _aa _60 _g0 _124 25440 3p000 20p00 15QQ0 teat 1Qp4Q =S�ptyCE, Pyp1 E 5p0Q _14o a Cea pr°lect CA island p' "37 BetSta County' Ahel East C°ntca G° OMp�S��E E _ G SLB tNFE � � ER -1956-01 11 • �3EC'T Np. 1 I POINT TO POINT PROFILE LINE .INT B-5 B-7 B-8 B-9 FSET 0 0 0 0 0 -10- -20- -30- -40- -50 10-20-30-a0-50 1 - -60- 70- -801 0 1000 2000 3000 4000 5000 6000 ' DISTANCE, feet Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA 2-D PROFILE Central Mantelli Prop. A-38 ROJECT NO. II-1956-01 i rn W (1) 'C Q 6 a V Y d C O •� c Z M IS � N J o C ` m A Y p d V N ' L Y J m W VI N U N N U N v1 J �O A W _ J Y � i 1 i _ i 1 1 1 1 1 � 1 1 bar = IOOkPa = 1.02 kg/cm2 400 SANDS 200 / / SILTY 100 SANDS � / 80 / / SANDY GO / / SILTS / 40 AND SILTS • / / /CLAYEY / SILTS / Z AND � 20 / SILTY CLAYS Q / W / / / CLAYS i m IO w 8 6 0 PEAT .� 4 - 2 / I 0 I 2 3 4 5 6 FRICTION RATIO , FR , SIMPLIFIED CLASSIFICATION CHART FOR STANDARD ELECTRIC FRICTION CONE FROM ROBERTSON AND CAMPANELLA, 1984 Bethel Island Area Project PLATE " .K L E I N F E L D E R East Contra Costa County, CA . i CONE CLASSIFICATION CHART B-1 PROJECT NO. 11-1956-01 ----- (4801) H1d30 o to o to o e o w N N t7 co tf ti W ' ♦-W W J d 1� a o z� 1 m N to p in o in m O) n -+ 0 1 m O) ~ O ~ .�. 0 0) C O i s m Z _ — _ _ _ _ _ _ _ _ _ D O 1 Np N L N o a fm o W CI Cn �^. X to • O N Cr _ —_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ c�o 0) Cb m o J, m in 1 N O O Z. W o N o N a O • E O n W � F0 �v Q O. C ^ o v V �onil 0 K pp n o � E W O < p U O] 2 C ea J _ E c a 0 0 U 1 G Cr ►- u >- a p . u J`�pp p L C In- a 0 0 41 LO ,^� O_ O �d o O J r U • r R" 4 pp l n p tn (sia-4aw) H1d30 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA CONE PENETROMETER NO. 1 B-2 PROJECT NO. 11-196-01 ! 1N N O O to O 1 0 1 \ CLWLa ! I W W. ! m { O 1� In 1►-K O O 1 I C O d o m 2 _ I� 0 I ] O N o I Ln N C3 0 W O I ! LM x I I W 6 W CL C'. — — — — — — Cr m I '� I0 Ln I O 10 N 1 G I � W ,y� u W 0 v IFS' I y O I I O • Ln E ' CL1 L1 V I r- o0 ! { C l oo N °e 1 W p Y L < e u C i a O F t v u w 5� o � o 0 I ' L C 1 In j O O o O y i L cc I O U 0 ' o th0 C) (s-ieiaw) Hld30 Bethel Island Area Project PLATE K L E l N F E L D E R East Contra Costa County, CA CONE PENETROMETER NO. 2 B-3 PROJECT. NO. 11-1956-01 i o Cr C3 W I (L 0 —W Z to w In 17— Lh rn or o 1 M CD — — — — — — -- — — — — — — — — — CA a 3 a 0 Lh W (L 0 w 0 S.— x La 5 CL gm to C2 1 0 0 92 1 0 to Ln IL C =U a U 1 C5 h L 41 IL tL C2 0 > Li C' e3 6 th L C In 0 a 4A L 0 Ir 0U 1L 0 (S-Jalaw) HicI30 Bethel Island Area Project PLATE k" K L E I N F E L D E R East Contra Costa County, CA PROJECTNO. 11-1956-01 CONE PENETROMETER NO. 3 B-4- ( to C%d 01 C9 La tL o IL 11 tn 0 —1 in CD — — — — — — — — — — — — — — — — — — — - Cr 0) .CU 46 7 In Z c b C .0 C3 o in C* 44 40 CL w cc CI LM Ln x LLA a- L" a H — - - - - - - - - - - - - — — — — — — in C' a '0 1N 0 0 0 5E La a U7 CD 4A > U C' L Co 0 0 L 0 Cc: .X 0 f 1i4 Cc (S-Ja4aw) H1d30 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA PROJEcr NO. 11-1956-01 CONE PENETROMETER NO. 4 B-5 Gaal) H.Ld34 N CY C1 C-) ILLa • w in Q 0 C, to o CD M .1^»CD 0 - �c U In rn (L a Z L, Q- — — — — — — — — — — — — — — — 0 Sh En "1 Qm o C O 41 C2 0 IL La m Ix CLC2 rn 0 oro IN L'n Z cc Ln U r a =o > ma C wa E ca. L CD U r 4.1 to a. C3 > U SL ivti C3 C3 o a 4J aU CL a E (S-JW10U) HJJ30 Bethel Island Area Project PLATE LEINFELDERH KR East Contra Costa County, CA PROJECT NO. 11-1956-01. CONE PENETROMETER NO. 5 B-6 I (laa,) Hld3C7 i 1 O to O 10 O to i C3 \ W J_ d U. IX C3 IL 'o = m � 10 I rn m 0 1 m m -+ I �� _O U C O d o` Z — — — — — — — — — V U.a o — 1 7 O a N _ — — — — — — — — — — _ in O " o �^ N L ✓ I • LaLa v m � . YK a-O — — — — — — — — — — — — — — — — — m ,o Lnco 1 Ito m 1 N O W W O Z N NZU C Myy u Cr C LnCL o I U p p u `-e C 0 (I � CO N O E 1 < • Y L „, u m 1 � L ✓ IL f0 0 0 1 > u o 410CS i L C I �n i o 0 o L O 9 I au CL 0 J Ix �e r . ti C3 1h L� (s-Jalaw) H1d30 Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA CONE PENETROMETER NO. 6 B-7 PIZOJEcr NO. I1-I956-01 • I (3001) Hld3a o to CV) to to O to N to c') M .. o �W W Ix.ti ¢Z O W o_ o Z m n o m in 0 QI m O t h m .ti a-K o — — — — — — — — — — — — r ttC" N 01 d u n C o �a 9 ZcL a O " tC r r N N o (L w O W x 0 W Q. (A 1L V gdo _ _ _ _ _ _ _ --- _ _ _ _ _ H ^ a O) to n CIO o N O 12 n O N O O m0 LN M O � r O O 4!ZC E C) W O in F O -v O U O d U ►-o 44r C oo n o E W L Y L � o C CD ^ J c p U i!` t v O U ►- u o_ o a r 0 L C O O o N m � L u Ix o 0 0 O J 1J 4 co o C sJa�aw) Hid30 r Bethel Island Area Project PLATE R] KLEINFELDER East Contra Costa County, CA I CONE PENETROMETER NO. 7 B_g i'ROJECI' NO. 11-1956-01 r j (lael) Hic_ O O tp O b O to O to r N .. c HW W aWLa �. L — d � O z 1 10 m m r -� O ^ m m E m :. _ ~� O K v N C O �\ r 2 �o p — — — — — — — — — — — — — — — - 0 ON `7 NO h .�.. L y o a 0 ' W� x N� Q W t1 w �v ■ ca Hurl.. m to on. m p 1 N O n O N f 0 _ W W v Z N 1C, (l N 4 o s' to E O Z . in V O ^ u u p / C 0 m o E W p o Y L < ut u N - < LI+ t N �+ m o 0 LS i o CL > u J Xpp h cLn L C v+ O O o 0 " ► I o L o 0 2:< °a o is o p J � � �4 K I p0 n G (s-Ja4aw) Hld30 Bethel Island Area Project PLATE K LEI NFELDER East Contra Costa County, CA CONE PENETROMETER NO. 8 B-9 r P�z��ECT NO. 11-I9�G-01 (tool) O to O to 0 U* 0 CIA CY clco I f L 0 ti O cl CD — — —Jl7 — — — — — — — — — — - a, c J3 8 1 94 CL •O x a in cp� — - - - - - - - - - - - - - - - - - — H to co I 0 0 0 IQ I A 0 ID C3 0 IL • AL U U > cp cc M' -j 0 U I • Ix IL L C a a ca Q J aft (9-JOIDW) H1d30 Bethel Island Area Project PLATE k" K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 CONE PENETROMETER NO. 14 B-11 (4801) Hld3(3 6 to O to 01 Cy C7 V) C3 cc wLd W (L 40 oin a 42 Ch W — — !2 0 Co W E — -- - — — — — — — — — — — in T o ao m 7- ; oo C m 0 3 0 a " N 1 C3 1h C 0- - — — — — — - — — — — — — — — — — — — Sh Ch 10 0 of 0 'D I (m 00 (D CA �w2 - a. C U 0 U CE > 4A Ir I C a w C3 Sh < L CID z U AX U 51 Sh L C L 0 CC CL 0 0 -J Li I I cc C2 In p th Hi d 3 11 Bethel Island Area Project PLATE nKLEINFELDER East Contra Costa County, CA - 1 CONE PENETROMETER NO. 11 B-12 PROJECT NO. 11-1956-01� . 4� IL cy 40 cy Cm LS CZ k" Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA CONE PENETROMETER NO. 12 B-13' PROJECT N10. 11-1956-01 - ' �N �� i (laai) Fiic3.+ i O N N C9 c O to to IL O 1 liftO O •. .. O 1 • ��o — — - - - - — — — — — - - — - C C p o 0 yti to th .. L M CL x x 0 n = H fit two m CU m o 0 0 c3 In �S > LJ .. - 1 W C o C 0 CIS C J In P: CL U 1 o Ix .' U L C 0 0 0 L o �� O Jo 3 E ilk (9-JO40w) Hid30 Bethel Island Area Project PLATE I kHK L E I N F E L D E R East Contra Costa County, CA CONE PENETROMETER NO. 13 B-14 I PROJECT- NO. 11-1956-01 CY Cm to I 0 9L to in U) 0 ce 1 M 1 C3 — — — — — — — — — — - to m L& IL C J3 -J 0 0 in in 7r 4J wC' IL Cr La CL.0. 2: C, —�— — — — — — — — — — — — 0-- !2IC2 1 0 in 0 A 0 0 to IN0 0 W La IL U U a =0U 40 C C3 Ix 40 L2 I -J oz a. > U L C 0 a C3 WE: (S-Ia-4aw) H1d30 Bethel Island Area Project PLATE k04K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 CONE PENETROMETER NO. 14 B-15 , (lael) i-ild3C; t ? O to O to O to C to .. I 40 .- .- N N N t i 10 1 .►W-W W J_ C�4 w I O IL 1m IO t!1t o th .t^.. O 0 � j C3 - 1 0 � o - - - - - — — — — — — — — o ' C p y\ m L Z It4..e C I o 0 1 r i o ------�- a- I '° is o tW x 0 c �U, s U) ■ m i ' o 0 � to o a W LJ W O 0 i o e ;�• E ? O a z� N n. C i^ O U O. iota � u � t c Ln E Y s u 1 _J U1 I C ll a61-J 1z v a , I � d ? i o n L C I i O N .. j O a I Z CL a io n t t u_ • y o TT�T— C3 WS t (sJa�aw� H 1 d3G Bethel Island Area Project PLATE KJK L E I N F E L D E R East Contra Costa County, CA PRO.1Lc r No. -19;6-0 CONE PENETROMETER NO. 15 B-16 0"J) H1c3G p ,p O b b O b N N C9 G • W.J-. ^ dcr) La 4 CL ! � m � ` - ^ o m CD CD m .-. o — — — — — — — — — — — — — N 07 u ,p O � d o C O o O N L . Cr Ln N c o W O I x &n a W d to m.. N La • cn 'o CLC' — — — — — — -- - .� _ — — — — — — — o o 'o m i o P O ,on o to 1 N � O O_ � W a 9 2 N O 5in c E W O ,n 1 a ! ¢ = o a C f U O u U :►-o 1 W o a L .n 0 ix 0 � N H n V - J LJ 1 v 1 0 m U U 1 d O • U - O L. —.---- 0 O o L O a ° z i� O3 J O (s-Ja4aw) Hic'30 L Bethel Island Area Project PLATE RIK L E I N F E L D E R East Contra Costa County, CA Pxo., .,cr No. 11-1956-01 CONE PENETROMETER NO. 16 B-17 r paa{) Hid3i] I a to o to o to o to tO P OV Oy t:) CS '7 Q f ' P 1 j i t 1 ^ O - a o Iwo 1 a + O n N O s 1 1 • - la — — — — — — -- - n + C 0 a to } 13 Z ff' a I r W 1 j p 1a o 0 h + T." N t t So 55 4-A � W� V 1 KLLI IL L -(- • C; I � — — — C — — — — — — O N a �r...T.-....r.,-r CD 4 Q N t a ta �� • lu pa Ln vv„ O w E L' t O i � irq 1 I cc J i W � oa N ..�.�-.Y. O r E x o .�-. CL u n .o • 40 a U 1 - L a t¢ t!} CL J o 'A C3 f11 a N o ^ H1d30 Bethel Island Area Project PLATE knKLEINFELDER East Contra Costa County, CA I'ROJECI' NO. 11-1956-01 CONE PENETROMETER NO. 17 6-18 i —1 (1081) H1d3a ! I O tp O LO O tO O b r r N N N N \ I W W 4 1 o_. 0 IL o I �o n w i p r, Inr o m o % to mw I ! K O — — — — — — — — — — — — — — — — — — — — Q C O iL p -� 2 CL 9 4 O '•f i o �^ o N 4 IL ° W x K Ito 133 i ,n p - H m I ^p — — 1A — — — — — — — G — — — — — — —IL 1 ^ m i o n o t� O N O O W LJ W v 4 Ir O ° Ito O 7 lin E CL o ;.�--o 0 u 4J K I Op h � E L! ° Y L m Iz N - < 4 N a I LCI O " a M � O3 o ! J ^ p Lf w I 4 C p T T T T-'-• T-- . I j (s-la-}aw) Hic30 Bethel Island Area Project PLATE KLEINFELDER East Contra Costa County, CA CONE PENETROMETER NO. 18 B-19 PROJECT NO- 11-1956-01 I (1801) Hld34 0 too w o to b r N N l9 f7 Q w 8y IL1 O = I n o ^ q w O 1 m o L Z �g 0 0 M $ a . • a A = HMt^ _ — _. , _ _ _ _ - - _ O ^ 0a O O N w O w = C A [ ^ O v �S v c < C m � C A .Ji w M 0 _ U 1 O w d u w w 0 o O L o �3 a� a� th H1d30 Bethel Island Area Project PLATE KLEINFELDER East Contra Costa County, CA PROJECT NO11-196-01 CONE PENETROMETER NO. 19 B-20 . F-- S I E V E A N A L Y S I S H Y 0 R 0 M E T_E R 3* 1.6" 3/4" 3/8" *4 *8 *16 #39 #60 #108 #200 lee - 98 11111F 80 TO Z 6 IV) Se z 40 30 2 10 18 1 0.1 0.01 0.001 PARTICLE SIZE mm GRAVEL SAND FINES coarse fine coarsel medium II fine SYMBOL BORING DEPTH CLASSIFICATION B-1 11.00 GRAY GREEN SILTY SAND (SM) Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA . C-1 PROJECT NO. 11-1956-01 GRAIN SIZE DISTRIBUTION S I E V E A N A L Y S I S H Y D R O M E T E R 3" 1.S" 3/4" 3/8" #4 #8 #16 #30 #SO #100 #200 iee 90 80 TO Z 6e w m N Q 0 50 F- Z W U IL 40 30-- 20 0 20 10 i 0 10 1 0.1 e.01 0.001 PARTICLE SIZE - mm GRAVEL SAND FINES coarse tine coarse medium Tine 1 I SYMBOL BORING DEPTH CLASSIFICATION 0 B-1 26.50 TAN SILTY SAND (SP-SM). . I ' i Bethel Island Area Project PLATE KLEINFELDEk" R East Contra Costa County, CA GRAIN SIZE DISTRIBUTION C-2 PROJECT NO. 11-1956-01 i S I E V E A N A L Y S I S 1 H Y D R O M E T E R 3" 1.5" 3/4" 3/8" #4 iib #16 930 #SO #ie0 #206 leo III ITF] se 80 TO Z 60 M N N � 50 Z W U Q: a 40 30 20 10 0 ie 1 0.1 6.01 0.eel PARTICLE SIZE - mm GRAVEL SAND FINES coarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION B-2 21.00 GRAY GREEN SILTY SAND (SP-SM) Bethel Island Area Project PLATE k" K L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-196-01 GRAIN SIZE DISTRIBUTION C-3 S I E V E A N A L Y S I S I k Y D R O M E T E F 3" 1.6" 3/4" 3/8" #4 88 #18 #30 #50 8100 8200 100 90 @0 70 Z Be H N N Q IL se F- z w U C J 40 3 0 � Ell I 20 10 0 10 1 0.1 0.01 0.001 PARTICLE SIZE - mm GRAVEL SAND FINES coarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION ❑ B-3 11.50 GRAY GREEN SILTY SAND (SP-SM) Bethel Island Area Project PLATE k" K L E 1 N F E L D E R East Contra Costa County, CA ' PROJECT NO. I1-196-01 GRAIN SIZE DISTRIBUTION C-4 S I E V E A N A L Y S I S H Y 0 R 0 M E T E R 3" 1.6" 3/4" 3/8" *4 #8 #16 #30 #50 #100 0200 SO so— Z 60 so z LLI ir w 40 IL 30 29 10 PARTICLE SIZE mm GRAVEL SAND PINES coarse I fine coarsemediummedium fine SYMBOL BORING DEPTH CLASSIFICATION 0 B-3 31.50 TAN GRAY SILTY SAND (SP-SM) Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA GRAIN SIZE DISTRIBUTION C-5 PROJECT NO. 11-1956-01 S I E V E A N A L Y S I S I O R O M E T E R 3" 1»5" 3/4" 3/8" #4 #8 #I6 #38 #58 #108 #208 100 90 80 ti 70 '� Z 60 M M (Ii Q W U UJ 40 38 20 10 0 10 1 8.1 0.01 8.001 PARTICLE SIZE - mm �^ GRAVEL SAND FINES coarse fine coarse medium J fine SYMBOL BORING DEPTH CLASSIFICATION B-5 33.50 LIGHT BROWN SILTY SAND (SP-SM) Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA NO, II-I95b-OI GRAIN SIZE DISTRIBUTION C-6 PROJECT f S I E V E A N A L Y S I S H Y 0 R 0 M E T E R 3" 1.6" 3/4" 3/8" #4 #8 #16 #30 #60 *100 #200 ISO 11T 411 11111 11111 9" '70 Z 60 tt (L so Z W 0 EL w 4 30 20 10 18 1 0.1 0.01 0.081 PARTICLE SIZE mm GRAVEL SAND FINES coarse finecoarse 1medium fine l SYMBOL BORING DEPTH CLASSIFICATION 0 B-6 7.50 GRAY TAN SILTY SAND (SP-SM) Bethel Island Area Project PLATE k K L E I N F ELDER East Contra Costa County, CA L PROJECT NO. 11-19-56-01 GRAIN SIZE DISTRIBUTION C S I E V E A hh A L Y S I S H Y B R 0 M E T E R 3" 1.5" 3/4" 3/8" #4 #8 #15 #30 #SO #100 #200 100 1. 1 N 90 80 70 Z 60 M N � 50 Z U � W !W 40 30 20 30 0 ll 111 1 1 10 1 0.1 0.01 0.001 PARTICLE SIZE - mm - GRAVEL SANG FINES coarse Tine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION 0 B-7 11.50 GRAY BROWN SILTY SAND (SM) Bethel Island Area Project PLATE knK L E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 GRAIN SIZE DISTRIBUTION C_g I E V E A N A L Y S I S H Y 0 R 0 M E T E R 3" 1.6" 3/4" 3/8" .#4 #8 #16 #30 #50 #100 #200 lee 90 8@ Z SO N 0) C s t- o Z w m U1 4 - IL 0 30- 20-- 10 10 1 0.1 8.01 8.001 PARTICLE SIZE mm GRAVEL SAND FINES Coarse_] fine icoarsel medium Ifine SYMBOL BORING DEPTH CLASSIFICATION 0 B-7 16.00 GRAY BROWN SILTY SAND (SM) Bethel Island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA GRAIN SIZE DISTRIBUTION C-9 i PROJECT NO. 11-1956-01 S I E V E A N A L Y S I S H Y D R D M E 7 E R 3" 1.6" 3/4" 3/8" #4 #8 #16 430 #60 #100 #200 108 8@ 8@ Z0 Z 68 M N ' N Q A Be Z W • U D: IL 48 38 28 10 - . 8 10 i 8.i 8.81 PARTICLE SIZE _ mm ' GRAVEL SAND FINES coarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION 13 B-8 11.00 LIGHT BROWN SAND {SP} Bethel Island Area Project PLATE k" KLEINFELDER East Contra Costa County, CA GRAIN SIZE DISTRIBUTION C-10 PROJECT NO. 11-1956-01 S I E V E A N A L Y S I S H Y G R O M E T E R •w w » 3 1.6.. 3/4 3/8w #4 #S #16 030 #60 #100 #200 100 � 90 J i S0 i ?0 Z 60 fs N Q F- 50 Z fiJ U a a 40 30 . 20 10 0 10 1 0.1 0.01 0.001 PARTICLE SIZE - mm GRAVEL SAND FINES coarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION B-9 11.00 GRAY SILTY SAND (SM) Bethel Island Area Project PLATE K LEI NFELDER East Contra Costa County, CA GRAIN SIZE DISTRIBUTION C-11 PROJECT NO. 11-1956-01 S I E V E A N A L Y S I S H Y 0 R O M E T E R 3" 1.5" 3/4" 3/8" 04 #8 #18 #30 #50 #180 #200 - 100 90 80 TO '!0! °x sa H N d U. Be F- Z lU U a IL 40 j i 30 20 • 10 0 i 18 1 0.1 0.01 0.001 PARTICLE SIZE - mm _ ' GRAVEL SAND FINES coarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION ❑ B-10 3.50 RUSTY BROWN SILTY SAND (SP-SM) i Bethel Island Area Project PLATE knKLEINFELDER East Contra Costa County, CA PROJECT NO. 11-1956-01 GRAIN SIZE DISTRIBUTION C . 12 � IV I ' 1 l S I E V E A N A L Y S I S H Y D R O M E T E R 1 3" i.5" 3/4" 3/8" *4 08 *11S 030 *58 *188 *200 180 S0 88 , 78 z se M U) U1 Q CL I- 50 2 w U Q: CL 40 30 20 20 8 i8 3 8.1 0.81 0.001 PARTICLE SIZE - mm GRAVEL SAND FINES coarse fine caarse medium I fine SYMBOL BORING DEPTH CLASSIFICATION '❑ B-10 7.00 GRAY GREEN SILTY SAND (SP-SM) Bethel Island Area Project PLATE K L'E I N F E L D E R East Contra Costa County, CA PROJECT NO. 11-1956-01 GRAIN SIZE DISTRIBUTION C-13 L S I E V E A iv A L Y S I S H Y D R O M E T E R 3" 1.6" 3/4" 3/8" #d #8 #16 #30 its@ #100 #209 100- 9 80 'k Z 60 N N 4 F- 50 Z w U a C 40 30 20 1@ @ 8.01. PARTICLE SIZE - mm GRAVEL SAND FINES coarse fine coarse medium, fine SYMBOL BORING DEPTH CLASSIFICATION O B-32 3.00 BROWN SILTY SAND (SP-SM) Bethel island Area Project PLATE K L E I N F E L D E R East Contra Costa County, CA (GRAIN SIZE DISTRIBUTION C-14 PROJECT NO. 11-1956-01 S I E V E A N A L Y S I S H Y D R Q M E - E R 3" 1.6" 3/4" 3/8" #4 #8 #16 #30 #60 #100 4200 100 90 $0 70 Z 60 H C) d � se z _ w u cr � 40 30 20 10 0 i0 1 0.1 0.01 0.001 PARTICLE SIZE - mm GRAVEL SANG FINES coarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION B-12 7.00 GRAY GREEN SILTY SAND (SM) 4 Bethel Island Area Project PLATE K LEINF ELDER East Contra Costa County, CA PROJECT NO. 11-1956-01 GRAIN SIZE DISTRIBUTION C-15 .l. S I E V E A N A L Y S I S H Y D R O M E T E R 3" 1.5" 3/4" 3/8" #4 #8 #16 #38 #60 910e #200 Lee ` 90 � 88 ,� Ire i Z 60 M N � Q IL F 50 Z U a ae • 38 20 18 � 0 10 1 0.1 e.01 0.081 PARTICLE SIZE - mm GRAVEL SAND FINES coarse fine coarse medium fine SYMBOL BORING DEPTH CLASSIFICATION 0 B-12 11.50 GRAY GREEN SILTY CLAYEY SAND (SC) Bethel island Area Project PLATE k" K L E I N F E L D E R East Contra Costa County, CA GRAIN SIZE DISTRIBUTION C-16 PROJECT NO. 11-1956-01 S I E V E A N A L Y S I S H Y D R O M E T E R 3" 1.5" 3/4" 3/8" #4 #8 *16 #30 #50 *100 #200 100 se se TO ' Z 6 0 N N ' N Q IL se z UJ U UJ 40 30 20 10 0 10 1 0.1 0.01 0.001 PARTICLE SIZE - mm GRAVEL SAND FINES coarse fine coarse medium I fine SYMBOL BORING DEPTH CLASSIFICATION p - B-13 6.50 GRAY GREEN SILTY SAND (SP SM) Bethel Island Area Project PLATE KLEINFELDER East Contra Costa County, CA PROJECT NO. 11-1956-01 GRAIN SIZE DISTRIBUTION C-17 I S I E V E A N A L Y S I S H Y D R O M E T E R 3" 1.5" 3/4" 3/8" *4 #8 *IS X30 *SO *100 *200 ie0 9Fill 11� 1 111111 11 11 IN I e •� ee �e Z 60 M N N Q a F 50 Z W U Q: IL 40 30 20 10 0 10 1 0.1 0.ei 0.e01 PARTICLE SIZE - mm _ GRAVELSAND coarse fine coarse medium fine FINES SYMBOL BORING DEPTH CLASSIFICATION ❑ B-13 21.50 GRAY GREEN SILTY SAND (SP-SM) Bethel Island Area Project PLATE K LEI NFELDER East Contra Costa County, CA GRAIN SIZE DISTRIBUTION C-18 PROJECT NO. 11-1956-01 i i .. APPENDIX D METHODS OF MITIGATION OF POTENTIALLY LIQUEFIABLE SOILS This section of the report outlines several ground modification techniques that may be used primarily to mitigate liquefaction or the effects of liquefaction. These are: 1. Dynamic Deep compaction. 2. Vibrocompaction and Vibroreplacement. 3 . Soil Mixing. 4. Pile Foundations. 5. Slurry wall cutoff and permanent site dewatering. The above ground modification alternatives are discussed briefly in the following paragraphs. Several contractors were contacted •�' and have provided rough estimates of the anticipated unit costs for performing these services. The anticipated relative effectiveness, difficulties and estimated construction schedule J based on our and the contractor's experience for each of the alternatives are also discussed. 1. Dynamic Deep Compaction Dynamic deep compaction consists of a large crane dropping a weight in freefall. Weights generally range from 15 to 30 tons and are constructed of box-steel and concrete, sheet-steel or mass reinforced concrete. The purpose of dynamic deep compaction is to increase the relative density of granular soils containing less than 20 percent fines. The treatment is achieved by performing a series of heavy tamping passes to provide improvement to the soil base layers. These drops are generally wide spaced and are performed with a heavier weight. Subsequent to these, a series of closer spaced, lighter weight drops are made to improve the shallower layers. For this project, use of a. lighter weight- may be appropriate throughout the improvement process. The use of dynamic compaction on soils containing higher percentages of silt and clay must be phased since there must be time to allow pore water pressures that have built up to dissipate. At the site, fines contents are generally below about 15 percent and pore water pressure dissipation should occur rather rapidly. Further, larger areas aid in providing continuity to the project and reduces costly down time. We have discussed the soil conditions encountered with representatives of GKN-Hayward Baker and Geo-Con, Inc. , specialty contractors in ground modification and site improvement. Based onpreliminary discussions, we were informed that the cost of this method would range from $0.60 to $0.80 per square ft. This does not include backfilling of the depressions nor follow up testing and monitoring to evaluate the improvement. We were informed that this typically costs an additional $0.20 to $0.40 per square ft. Therefore, total costs for this method of improvement may range from $0.80 to $1.20 per square ft. Maximum anticipated costs for this method are estimated to be $1.50 per square ft. Please note that these values are rough estimates and the actual cost may vary according to the abundance of fill material at . the site and the size ..of the area that is to be improved. Large vibrations produced due to the dropping of the weight could affect adjacent structures, buildings and the existing levee. According to recent measurements, peak particle velocities of 1.5 in/sec at 100 ft. , and 0.4 in/sec at 200 ft. are common. our concerns deal with shaking the existing levee ' and possibly causing damage. Liquefaction could also occur under adjacent homes. Evaluation of the effects of these peak particle velocities on the existing levee and powerlines is beyond the scope of this report but should be investigated prior to implementing this method. This can be done by performing a test section away from structures. Densification should be performed laterally outward from protected areas to guard against potential progressive liquefaction. Pore Progressive liquefaction occurs when high g g pressures in the liquefied soils generate high enough pore r pressures to liquefy adjacent densified zones. Dynamic deep compaction may serve to reduce liquefaction potential, however it should only slightly aid in controlling levee underseepage and landslide pressure head. 2. Vibrocompaction a. Vibrofloatation This method consists. of using a vibrator, extension tubes and a supporting crane. The vibrator is electrically or hydraulically driven and utilizes eccentrically loaded weights that produce high centrifugal forces in a horizontal plane at a frequency of 1800 to 3000 rpm. The tip of the vibrator is pointed and may contain nozzles for jetting of water for easy penetration. This method is generally used in deinsifying clean sands to depths of 15 to 50 ft but can be used in shallower sand deposits. Sand backfill is usually '-used during the process. Vibrator diameters are in the range of 14 to 18 inches in diameter and the zone of improvement ranges from 4 to 12 ft based' on the soil type and vibrator power. The advantages of this system are that. it generally does not produce vibrations harmful to adjacent structures. The disadvantage of this method is that it is usually not very effective on sands with silt contents greater than 15 to 20 percent. A few areas of the site may have greater than 15 percent fines and may not be improved by this method. The cost of this method is estimated to be about $2.00/sq.-ft Trial areas should be performed to see if this method is applicable to the site soils. b. Vibroreplacement Stone Columns This method is similar to that described above except that during the withdrawal of the vibrator, the resulting cavity is filled with a course-grained material such as crushed stone or gravel. The stones form a compacted column that acts as a support for structures as well as a drain. The columns act as a drain to relief excess pore pressures that may develop during seismic events. For improvement purposes, stone column spacings are generally range from 4 to 10' ft. Capacities are generally on the order of 10 to 40 tons depending on the soil conditions. The cost of the method is approximately $11/linear ft of column or $2 to $13/sf. I 3. Soil Mixing This method involves the use of a crane-supported set of leads which guides a series of hydraulically driven mixing paddles and augers. As the ground is penetrated, stabilizing agents and other fluids are introduced to the soil through the center of each shaft. When the desired depth is reached, the augers are withdrawn leaving a stabilized soil mass behind that has reduced permeability, improved bearing capacity and structural support. I`. This method is generally effective on fine grained, soft .soils but has been adapted for use on silty and sandy soils. The method is most effective in reducing permeability by construction of a continuous wall. Advantages are that there is little to no damage to adjacent structures, and there is no need for excavation and backfill. Cost of this method however, is considered moderate to high based on the type of stabilizer used. 4. Pile Foundations Precast-prestressed concrete piles can be used to support pertinent structures at the site. Piles will reduce the potential for distress to building structures in the event of site liquefaction, by transferring structural loads to an underlying non-liquefiable soil stratum. Disadvantages of piles are that they do not provide support for the levees, roadways or roadway utilities. Costs of concrete piles including installation range from $12-$16/linear ft. For the purpose of preliminary cost estimation, a minimum length of 30 ft./pile or $420/installed pile may be used. A pile design would have to be performed to obtain the actual lengths. Each building would require several piles. 5. Slurry Wall Cut-off and Permanent Dewatering As an alternative to in-situ densification and pile support, the potential for liquefaction may be reduced by permanently lowering the watertable elevation below the depth of the liquefiable soils. This may be accomplished by a combination of construction of an earth-bentonite slurry wall and by implementing ..a permanent dewatering system to lower the water table. The slurry wall can be constructed about the proposed levee perimeter. Advantages of the slurry wall include: 1. Reduction of underseepage under the levee. 2. Elimination of pressure head on landslide soils, 3 . Reduce the potential for liquefaction, 4. Site and lake construction can be performed in the dry and, 5. Construction can proceed in phases by cutting off and dewatering a single-village at one time. Use of a slurry wall and permanent dewatering has some r disadvantages. . These are (1) the short and long-term costs of ill dewatering, (2) the need for lining or sealing the lakes, and (3) . shallow subsidence and increased settlement as a result of the dewatering. Of these disadvantages, the most prohibitive is the cost of dewatering which is expected to be-very high. The boring logs indicate that there is a clay layer which may be used as a cutoff, that ranges from 48 . to 56 ft below the present ground surface. Mr. Rick Hanford of Geo-Con, Inc. , a specialty contractor, informed us that the slurry wall may be constructed using a long-armed backhoe, for about $2..00/sq. ft. The total area is calculated by taking the linear length of the trench and multiplying by the depth of trench. For preliminary calculation purposes, a nominal slurry wall depth of 53 ft may be used for estimating the construction cost of the wall. Additional borings would have to be drilled to confirm the extent and thickness of the clay layer. Based on our conversations with the contractor, it appears that construction of the slurry wall would progress at about 120 to 150 linear ft/day. Dewatering would require well points or deep wells. Long-term dewatering might include the used of gravel drains and sump PUMPS- There are several factors affecting the costs of dewatering, and a dewatering specialist should be contacted if this method of construction is considered. We were informed that the cost of a placed synthetic liner for the lake areas would be about $0.30 to $0.40/sq. ft. As an alternative, clay may be placed as a liner. for the lakes. The relative cost of the clay liner is estimated to be about $1.00 to $1.20/cy. provided on-site material is available. These alternatives should be discussed with Harlen Glenn & Associates for compliance with their specifications, as well as with local earthwork contractors. �C1. ! Bohley/Maley Associates Engineering•Surveying•Planning V J 1.- rye A., 11: 19 o r►30 3 A fro svo �►�Z CYPRESS LAKES & COUNTRY CLUB Informational Report for THE PROPOSED LEVEE SYSTEM August 20, 199..2 Prepared by: BOHLEY/MALEY ASSOCIATES 1875 South Grart Street X/w Suite 5`0 San Mateo CA 94402 F= u- 1875 South Grant Street Suite 550 San Mateo California 94402 415.358. 1487 Fax • 415.358.1484 LOCATION The Cypress Lakes & Country Club project site is located in the Sacramento-San Joaquin Delta area of unincorporated north-eastern Contra Costa County. The project site, approximately 2.7 miles east of the Town of Oakley, is bordered by Bethel Island Road to the west, Sandmound Boulevard to the north and east, and approximately Rock Slough to the south. See the following page for a location map. EXISTING SETTING & HISTORICAL INFOR.,NIATION The site, situated in the -Hotchkiss Tract, is surrounded by approximately 6.7 miles of levees with all but the Contra Costa Canal levees maintained by Reclamation District 799 (RD-799). The existing levees do not meet the standards of the Federal Emergency Management Agency (FEMA) criteria for either the Short Terns Hazard Mitigation Plan Levee(HMP) or the Urban Standard Levee. The project area, as well as the Hotchkiss Tract, is classified as "Zone A22" under the FEMA Flcod Insurance Rate Map and is susceptible to inundation to a depth of seven feet above mean sea level. The existing levees are subject to tidal events of approximately one foot below the 100 year flood elevation, on an annual basis. FEMA REQUIREN,IENTS In order for the development to occur, the project must provide protection from the 100 year flood event occurring both interior and exterior to the project. The three alternatives to providing such protection are: 1. constructing raised homes, 2. elevating the entire site to above projected flood elevations, or 3. building a new levee system to FEMA Urban Levee Standards to protect the site from exterior flooding, and constructing on site storm water disposal systems to prctect the project from interior flooding. Considering economics, local, state, and federal requirements, we have determined that the most effective solution is to construct a new levee system around the project itself. FEMA requirement3 for such an Urban Standard Levee System are summarized as follows: Provide sufficient freeboard above the 100-year identified flood hazard elevation, incorporating storm surges and wave runup. Evidence that all structures .-r pipes that penetrate the levee are fitted with closure devices are structural parts of the levee and have been designed according to sound engineering practice.- An engineering analysis demonstrating that no appreciable erosion will occur during the 100-year design event. ,An engineering analysis that evaluates the stability of the levee embankment and foundation, both statically and dynamically. An engineering analysis demonstrating that the de*s,icn freeboard is maintained after settlement. An engineer*,ng analysis of the drainage internal to the levee system. < ~ m U oLu � Y Q O zJ jX.N O W o �- En a LL = o m : Cis GVOb ONYISI 3H.L38 N H ^ W Z Q' F-Lj J z Y v' pZ mN Q J 0 w NO m 0: N ON W N Z } 1 Z � J V LLJ En LyU o 0 J Z fLic Wm IRK - 3 2 BETHEL ISLAND DUTCH......SLOUGH O Q O O. O U) o h W� LJ PROJECT i m' SITE o CYPRESS ROAD ? HOLLAND TRACT PROJECT LEVEE RECLAMATION DISTRICT NO. 799 BOUNDARY PROJECT LOCATION NO SCALE PROPERTY LINE PROJECT �18'----{ SITE I i 3.1 1� im HEIGHT OF LEVEE VARIES 2.T DEPENDING ON EX GROUND ELEVATIONS. MIN IV t MAx 1Y * �• TYPICAL LEVEE SECTION NO SCALE T 1 - N X N ui J a O r~ L O Q3 U W r a � _o O w Z v W II Cy J 0 m C J0 ILO N Q J w. Q I �X w 'o -6 U V) O > Q 'O 0 M. . > C O U C: - � O .Q > N �0 N CL O OL 1E.CL rt i A formal operations and maintenance plan for both the levee and the internal storm drainage system. Technical documents that are sent to FEMA, are reviewed by Michael Baker & Associates who are under contract to FEMA to advise the Agency regarding the technical merits of the data submitted. In general, the Army Corps of Engineers standards for levee structural stability and protection are the criteria used by the Agency's consultant. PROPOSED LEVEE CONSTRUCTION The project levee will be designed with a crest elevation of 110.2 (MSI. + 100), which is consistent with the ultimate required elevation of the RD-799 levees, and which is 0.2 feet higher than the FEMA required levee The proposed project levee will parallel the existing Sandmound Slough levee approximately 200 feet to the west of the Sandmound levee for approximately two thousand feet. A setback easement will be provided along the outboard side of the levee for raisin- of the crest elevation if so needed in the future. Material for construction of the levee will come from the excavation of on-site soils for the proposed interior lake/channel system. A report entitled "Evaluation of Proposed Levees" prepared by kleinfelder, Inc., and dated August IS-92, provides measures to minimize the affects of subsidence and liquefaction as Nvell as recommended techniques for stabilization and densification of soils. RD-799 LEVEE FAILURE ANALYSIS Types of levee failures in the Delta region have included overtopping, foundation failure, and piping due to burrowing rodents. Generally, levee failures have started small but then erode to sizeable magnitudes. This analysis assumes a levee failure occurring on the Sandmound Slough levee adjacent to the project site, and would essentially be a worst case scenario. Other assumptions contributing to this scenario include a tidal/flood event to elevation +7.0. The purpose of the following analy3is is to evaluate drainage patterns of flood waters indme << , event that the project levee is built and the Sandmound Slough levee undergoes a major failure. However, because of the compleK nature o�.-a levee breach and thy.fact Lhat a number of variables cores in to play, our Prizlysis has been simplified by holding certain variables constant. For e=xample, under all possible scenarios (overtopping., piping, slumping, etc.), erosion will cccur xvhi-.h will allow more water over/through, which will then increase the erosion rate, and so on. For this reason, erosion is not considered to occur. other than a discussed below. A second variable (olso connected to erosion) is that the area through which the water is flowing over/through will constantly change due to erosion. To simplify this second 'variables, we have elected to assume a breach 50 feet wide through the entire Sandmound levee, with the bottom of the breach at mean sea level. (elevation 0.0). This may appear to be a doomsday approach to the analysis, however we believe it recognizes the fact that erosion would occur, without trying to quantify the erosional rate. With this geometric configuration, the breach Would esstr.tially act similar to flow over a weir. The next considCration is that the .pow through th13 nrCach will vary as the tide varies, which for simplification-purposes twill be assumed as-a sine curve. Depending on the stage of the tide, there will be a specific volume of water going through the breach per unit of time. For our case, the maximum overflow rate would be on the order of 2,435 cubic feet per second (almost 1,100,000 gallons per minute), which occurs when the tide is at its maximum stage. For one tidal cycle, therefore, a total of 670 acre feet of water will flow through this theoretical 50 foot-wide breach. Of interest is that the backwater curve that occurs upstream of the breach (within Sandmound Slough) requires that the water accelerate to 11.6 feet per second (FPS) to flow through h the breach. Under any circumstance, this is a highly erodible velocity. Appendix A shows the relationship of flowrate and cumulative flow versus time for the theoretical 50 foot breach. Appendix B is a compilation of peak flowrate and total flow over ona tidal cycle for breaches of varying lengths. Since the existing RD-799 acreage is approximately 3,000 acres with an average elevation of mean sea level (0.0), to flood the entire Hotchkiss Tract-to this elevation would take on the order of 10,500 acre feet of water, or, as shown in Appendix B, a breach of approximately 800 lineal feet. By removing the volume of the project area from the Hotchkiss Tract floodzone, the breach length required to flood the reduced area to mean sea level reduces to apprbximately 400 feet After the water has pass-ad throueh the Sandmound levee, it would tend to spread southerly, westerly, and northerly, if there were ro project. For this particular example, the rate of spreading would be dependent on the specific flowrate at any particular point in time. An analogy would be an alluvial fan, in that the waters would generally spread out in the form of a fan. The direction of spreading would be along the path of least-resistance. Under the project scenario, the top of the fan would be cut off by the project levee with the water flowing in both a northerly and southerly direction. The worst case, from a water velocity standpoint, would be for the theoretical 50 feet by 7 feet levee breach to occur at highest tide. At this stage, there would be maximum volume of flow along with maximum velocity of flow close to the breach. For discussionpurposes, the "channels" to the north and south would each be on the order of 200 feet wide. As the water spills out of Sandmound Slough, it will go through critical .2 0 depth which will put the water into a supercritical flow regime. . As it flows down the Sandmound levee face, it will remain supercritical, (unless interrupted by a house, trees, etc.) until reaching the level area at the base of the Sandmound levee. At this or some other point, the water will go through a hydraulic jump which will release energy, raise the water surface, and decrease its velocity. Because of the above mentioned 11.6 FPS, substantial erosion may occur reasonably close to the base of the levee. This erosion will have the effect of increasing the depth of the water, thereby continuing to cause, and also containing, the hydraulic jump. Appendix C is A listing of the velocity of the water within the "channel" for various depths. The reason the velocities are so much lower than the water coming through the Sandmound levee is because of the width between the two levees within which the water can spread out. Focusing in on the area between the two levees, we f'ind that it is on the order of 9 acres (200 feet wide by 2,000 feet long). Under the "Cumulative Flow" COILImn in Appendix A, we note that a total VOIL-Me Of I acre foot of water has gone through the breach after a 15 minute period; 6 acre feet after, 30 minutes; and lal acre feet after 45 minutes. An approach to quantifying the depth of flow (and the velocity) is to assume that the total amount of water that has gone through the levee during a chosen period of time will have some depth at the middle of the 2,000 foot reach between the levees, and zero depth at each end of the 2,000 foot reach. This approximation results in a depth of about 1.3 feet after 30 minutes and 3.3 feet after 45 minutes. The commensurate velocities are approximately 5 FPS and 2 FPS respectively. Although this approximation appears to provide answers, in reality the form of the water surface profile between the two levees is rather complex. However, the one known is that wherever a breach occurs, there will be substantial velocities that would probably destroy any structure in its path. This is due to the fact that the greatest velocities occur at the breach itself and would occur whether or not the project is built. The likelihood of a failure of the Sandmound levee is a function of the type of failure. For example, if adequate vector control is performed by RD-799, the chances of failure due to , piping in the next 100 years (the 1% occurrence) is estimated at I chance in 20 (or, a piping occurrence happens once every 20 years). If the height of the levee is consistently maintained at elevation +9 by RD-799, the chances of overtopping are considered nil since there would be two feet of freeboard at all times within an area that has minimal, if any, wave runup. The most probable failure mode is slumping of the levee due to failure of the foundation soils due , to liquefaction or tris of strength of the levee soil itself. The possibility of this happening is ' a.function of when the next major earthquake occurs. LEVEE ACCESS The levees will be constructed with a top width which will allow access for maintenance and emergency vehicles. This will also allow the use of the levee top as a recreational path interconnecting with other trails and paths within the project. Three points of access are provided into the project site, Cypress Road to the east and west.and Sandmound Boulevard to the north. Access to the levee top for maintenance purposes will be gained at these three points as well as at a number of other locations within the project. Bohley/Maley Associates Engineering•Surveying•Planning i APPENDIX A FLOWRATE vs TIME Breach length = 50 feet Breach elevation = 0.0 (MSI.) Height of _ Tide above Cumulative Time MSL Fiowrate Flow (HRS) (FT) (CFS)_ (AF) 0.00 0.00 0 0 0.25 0.91 115 1 0.50 1.81 321 6 0.75 2.68 577 15 1.00 3.50 861 30 1.25 4.26 1,157 51 1.50 4.95 1,448 78 1.75 5.55 1,721 110 2.00 6.06 1,953 148 2.25 6.47 2,163 191 2.50 6.76 2,312 237 2,75 6.94 2,404 286 3.00 7.00 2,435 336 3.25 6.94 2,404 386 3,50 6,76 2,312 435 3.75 6.47 2,163 481 4.00 6.06 1,963 523 4.25 5.55 1,721 562 4.50 4.95 1,448 594 4.75 4.26 1.157 621 5.00 3.50 861 642 5.25 268 577 657 5.50 1.81 321 666 5.75 0.91 115 671 6.00 0.00 0 672 1875 South Crant 4treel Snitr SSt1 Snn Macro C-ili(nrnin a-mno etc +r^ •• "' ^�^ "^' Bohley/Maley Associates Engineering•Surveying•Planning APPENDIX B BREACH LENGTH vs FLOW Breach Total Peak Length Flow Flaw (FT) (AF) (-FS) 50 672 2,436 100 1,344 4.871 150 2,016 7,307 200 2,588 9,742 __. _. . 250 3,359 12,178 300 4,031 14,613 350 4,703 17,049 400 5,375 19,484 450 6,047 21,920 500 6,719 24,355 550 7,39 i 26,791 600 8,062 29,226 650 8,734 31,662 700 9,406 34,097 750 10,078 36,533 800 10,750 38,968 850 11,422 41,404 900 12,093 43,839 950 12,765 46,275 1000 13,437 48,710 1875 Soutli Grant Street Suite 550 San Mateo California 94402 415-ZSR. 1.1 A7 F,v d15. SR• I.iR.i hl � Bo ey/Maley Associates ' Engineering•Surveying•Planning APPENDIX C WATER DEPTH vs VELOCITY (north or south) ' Q=2,435 CFS Depth Velocity (FT) (FPS) 0.5 12.2 1.0 6.1 1.5 4.1 2.0 3.0 ' 2.5 2.4 3.0 2.0 3.5 1.7 4.0 1.5 4.5 - 1.4 5.0 1.2 5.5 1.1 6.0 1.0 6.5 0.9 7.0 0.9 R 1171 South Grant Street Suite"0 San 11meo California 9.,,o2 415.358. 1487 Fax • 411 318. 14114 r r r � $ r U Cf d Y OY tr d p1 2 rV S n Q 6. OU. �' ¢ V1 e r ° u O Y , Z u O O O Y °' N r o r r Y C` 7 d O 2 i `Guull, NIP os r a i T C7 GGG G N, Ca .. r d V Z , ro o °! q V1 �b o n o � ,a 'S • r N v o Noar. a Qac 7t? � OCT 21 192 16:38 027 P02 1 File No. 20-3179-01 October 30. 1992 ' Lynn Jochim Chartered Land and Cattle Company 101 Ygnacio Valley Road, Suite 400 Walnut Creek, CA 94596 Subject! MMRMA77ON ON EXCAVATION TEMMQI FI;, GROUNDWATER MONITORING, AND SUBSIDENCE CYPRESS LAEM PROJECT CONTRA COSTA COUNTY, CALIFORNIA ' At your request, presented in this letter are cnmments regarding excavation techniques, groundwater monitoring, and subsidence to be used in response to concerns by adjoining Party ownars. EXCAVATION Me to the presence of loose clean and silty sands to depths of approximately 10 to 15 feet ' along the perimeter of the project, it has been proposed to use Deep Dynamic Compaction (DDC) w1iniques to dw*ify thm materials tusl thus, mitnmizx the risk of liquefaction within this zone. DDC is a technique that involves dropping a heavy weight, in this case ' approximately 10 to 15 tions, repeatedly at a given location. The energy transmitted to the soil causes the underlying loose materials to density. The weight can be either concrete or steel and is usually dropped approximately 6 to 10 times at the same location. The weight itself is ' usually square or rectangular in shape and on the order of 2 x 2 or 3 x 3 feet in dimensions. The crater left by the repeated drops of this weight may be 4 to 5 feet in diameter. The weight is dropped on an approximate 8 to 10 foot grid. ' We have enclosed actual measurements by Hayward-Baker regardingardi the magnitude of vibrations normally caused by this technique as well as the "safe" criteria established by the Bureau of Reclamation and others. It is apparent that the accepted vibration limit corresponds to an approximate acceleration of 0.Ig or a peak velocity of 1.5 to 4.0 intsec.(at a frequency of 10-30 cps). On projects with similar soil conditions, vibrations measured 80 feet from the point of contact by a 10 ton weight were considered acceptable by current standards. Using a heavier 14 ton weight Increased the "safe" distance to approximately 150 feet. By this criteria, it is unlikely that homes situated east of Sandmound Boulevard would be significantly ' affected by the DDC operations where a smaller weight is used. Copyright 1992 KWnfetder, rte. page 1 of 3 OCT 21 192 16:39 027 P03 ' File No. 20-317"1 KLE1NFELDER ' October 30, 1992 As a precaution, however, instruments will be positioned at the property line closest to an ' adjoining residence, or with approval of the residents, adjacent to the home,and the vibrations monitored_ If,for some reason, the level of vibration exceeds accepted criteria, then either the size of weight or height of fall may be reduced to ensure that vibrations will be within the wAxptable range. I As an alternative, the loose clean and silty sands can be removed with heavy construction equipment and recompacted. Because of the granular nature of the excavated soils, it is very ' likely that a vibrating sharps foot or pneumatic roller of some kind will be employed by the contractor to achieve required compaction. Some vibration therefore, should still be antlelpated although to a lesser degree than with DDC;. We also note that additional noise and a longer ' construction period would result if heavy used to compact the underlying loose materials. GRO RMWATER MONY'[`dRE'fG In order to accomplish the DDC work around the perimeter of the project; it will first be necessary to lower the existing groundwater depth. It is tentatively planned to install a ' dewatering trench on the inboard side of the proposed dry land levee. The depth of time dewatering trenches will likely depend on ground&&face elevation and depth to groundwater. It is possible that the dewatering trench might be 15 to 20 feet below grade. Concern has been expressed that dewatering operations would significantly lower the depth of groundwater in the ' vicinity of adjacent residents -Anng Sandmound Roulevard. It has been proposed that monitoring wells be installed on an approximate 200 foot spacing, as close to the existing residences as possible. It is preferred that these monitoring wells be lockod.aDd located to t1m east of Sandmound Boulevard, closer to the residences. These monitoring well�vould be monitored daily for approximately one week to establish a trend and wliatevec tidal affects may exist, and thereafter on a wteldy basis- The monitoring wells would be installed prior to the , operation of the dewntering.system in order to provide background love]water depths. Should dic= nwniluring wells indivatc a drop in groundwater depth of approximately 3 to 4 feet adjacent to the existingresidences, then water will be discharged into the ditch that exists , approximately 20 feet from the outboard toe of the new levee. The purpose for discharging into the ditch would be to create an artificial mound of groundwater adjacent to the perimeter of the site. This should stabilize and eventually restore the groundwater levels east of ' Sandmound Boulevard. SUBSIDENCE MON O lNC In our opinion, subsidence monitoring involves a collection of survey measurements along sensitive arras. Since adjoining properly owners appear most cm=rned, we suggest that survey hubs be positioned near the eastern property line and monitored on a monthly basis. The time between readings can be further expanded should no movement be detected. In our opinion, because of the dense underlying soils, the likelihood of subsidence is very mmate. CWyrioht 1992 Cleinkider, Inc. POP! I of 3 ' OCT 21 192 16:40 027 PO4 ' File No. 20-3179-01 ktEiNFEIDER October 30, 1992 ' We trust this.provides the information requested. If you have any questions or need additional information, please contact us. RespeaWly submiued, ER, C. 1 L r ' Ron Heinen, O.E. Regional Manager RH:md Copyright 1942 Vainftldor, Inca Pope 3 of 3 OCT 21 192 16:40 027 P05 ' OCT-30-1992 11146 FROM HAYWARD BAKER, INC. TO 120994x30621 P.03 t . i t0 BLAST M AIM$ YITN SOUND, IBIASEOV OpSERVER , 5 TRANSIENT NOTION, NO BOUND, 'INPARTIALI OBSERVER U . c MI O 0.5 TIC �' 1tANTECA r. .J v 042 i W W CANINO . 0.1 � i DEL RIO l o +v rn 0 0.05 :2 ! UNION �ITY • g ► or -6n 0902 -� 1t60 ' I 0.01AMMUMLOW ■ 1 10 100 t UQU ■ DISTANCE - (t F19,3 Vibration amplitudes from dynamic soil-compaction end human response thresholds. TOTAL P.03 , 02? P066, 480621199 TO OCT 21 *92 16:41 WyUWD BPXSRINC OCT-30_1992 11 45 FROM � tXa G In X0.4 •O �! ww $ {> �w+b . .g C ~RC d 0 ' g O� tw O � Y �� •• C -',�. V do�� •� ,♦,-` .� i• o •�~L;� • �9 ,�i '�,S �y A � �r CAN 4L .-. .., Cl . C •, «r � �e.JG IL M.�j•� A JA vs pl Yr T. � �y '" � ��� C ..e � V V � � �h I•� ` �7 �Yj. V YT M � �r"�W �, !r. .� y w C N C 4� i[� �: }y�•�y ;•,!is N .. �.r� P ,�► 144 C7 : .& 14 •N C'' p . S�•� ! (! '!j ~ 4 Y t 1� F W '� O I ; W� 70" � 'i•- • � �r � � Y+ �i a .r+.r.'"'•n 53 33 � r .0 •• �. C .� �d r �.,., V !•� .i� �f:� �j'�' '�i .moi ,,,,,_.... `� �•epi o t.. � �� � ��� it .�' -„�....""'...� `•4 Zig � 10* 0. iff gg V N R yrs ! y�,•u�`RLt�1M'to4d q o OCT 21 192 16:42 027 P07 , 146 Blasting Operations have very responsive overburden, we uiuhiply 0.0055 in by 3. Taklag this figure(0,01b5 in)and looking al Table 10.3 g1vCe the acceleratiou and its safe ' limits.Using the ground conditions of Table 12.2,we have for average over- burden 15 Hz,for abnormal overburden S Hz,and for rock outcrops 20 to 80 Hz.With the same overburden as in'i'able 112,the value is 5 Hx.I1lterpolat• 1 ills between 4 and 6 Hz on Table 12.3 and comparing the displacement we find that it is a safe level. The Scaled Distance Formula: Another method for determining the safe limits for ground vibrations is the scaled distance formula. , W - (Df) ' where D. = 60, D distance. and W ¢ maximum Pxpin�ivP weight. lb. 1 Using the previous example. 50 lb at 400 ft, we find W = (400160)1. This would indicate that the blaster should not use that much explosive. Using the tables we found that this amount is acceptable,but the scaled distance formula does not permit it.Obviously the tables are mora accurato;however, TABLE 10.3 Acceleration . Frequency,Hz 1 Displace- msnt,in 2 4 e 8 10 15. 20 , 0.24 0.1 0.38 0.86 1.5 2.4 8.4 9.8 0.22 049 0.35 0.79 1.4 2.4 5.0 8.8 ! 0.20 0.060 0.32 oat 2.3 2.0 4.5 4.0 ' 0.18 OA72 0.29 0.65 1.2 1.8 4.1 7.2 ' 0.16 0 064 0.2R 0 S a 1.0 1.8 .Pe 3.6 6.4 0.14 0.055 0.22 0.50 0.90 1.4 S.2 5.6 0.12 0.048 0.19 0.43 0.77 1.2 2.7 4.8 0.10 0.040 0.18 0.36 0.64 1.0 4.00 08 0.032 0.13 029 0.51 0.612.2 Le S.2 0.06 0.024 0.10 0.22 0.36 0.61.3 2.4 0.04 . 0.015 0.06 0.14 026 0.4 .11 1.6 0.02 0.008 0.07 007 0.1! 0.2 0.4 0.8 , OAS 0.004 0.016 0.035 0A64 . 0.4 0.008 0.0032 0.013 0.029 0.051 '1034: ZO2 0.3 0.006 00024 0.010 0.022 0.038 0.2 0.004 0.0016 0.006 0.014 0.026 0.2 OA02 0.0008 0.003 UAU7 U.013 DAM `'e 0.0004 0.0016 0.0036 0.006 0.01 0.�0.0006 0.0008 O.00za O.00ZO OROS 0.008 0.02f,��� U'rr'' 0.0006 0.0002 0.0010 0.0022 0.004 0.005 0.01 0.0004 40002 0.0006 0.0014 0.0026 0.004 0.01 0.018 / n 0.0002 ' 0.0001 0.0003 0.0007 0.0013 0.002 0.004 0.006 • /v`7' 0.0001 0.0000 0.0002 0.0004 DAM 0.001 " '6.0oz OAo4 solea: Seismic Effects of Ne=y BLsting,Bureau of Mina Bulletin 442,1942. 1 i i i 1 i 1 1 ' Appendix F Will Serve Letter from Oakley Water District OAKLEY WATER DISTRICT P.O.Box 127 April 30, 1992 3100 Main Street,Suite 278 Oakley.CA 94561 ' 510.625.3798 Fax 510.625.0814 Ms . Lynn Jochim Directors: Chartered Land & Cattle Company V.Wallace Allen 101 Ygnacio Valley Road, Suite 400 ' Bill E.Brandt Walnut Creek, CA 94596 Kenneth L.Crockett Howard Hobbs RobertWightman Re: Cypress Lakes, Subdivision 7562 General Manager Dear Ms. Jochim: &Secretary: Leonard Celoni This is to inform you that Oakley Water District will ' supply water to the above referenced subdivision providing Attorney: all the District's regulations and specifications are met. Frederick Bold The area is not presently within the boundaries of Oakley Water District and would have to be annexed not only to Oakley Water District but Contra Costa Water District as well. Enclosed are copies of the District's regulations numbered 1, 2, 3, 4, 5, 6, 7, 8, 9, 109, Request and Consent to Annex Land to Oakley Water District, Procedure for Annexation of Land and a Schedule of Processing Fees for ' Local Agency Formation Commission. There will be proposed amendments to some of the District's regulations for the Board's consideration at the May 27, 1992 meeting. If there are amendments, we will send you copies after the meeting. Should you need more information, please let me know. Yours truly, (Mrs. ) Bonnie McLain ' Administrative Aide :bm ' cc: Jon Toyoda, Camp, Dresser & McKee REGULATION NO. 1 RATES AND CHARGES FOR WATER SERVICE Section 1. Monthly Service Charge A monthly service charge shall be paid for each connection to the District's water distribution system as follows: Size of Meter Service Charge 5/8 x 3/4 inch 6.00 1 inch 15.00 1-1/2 inch 30.00 2 inch 48.00 3 inch 105.00 4 inch 189.00 6 inch 420.00 8 inch 720.00 10 inch 1,140.00 12 inch 1,500.00 14 inch 2,160.00 ■ 16 inch .3,000.00 Section 2 . Ou ntity Charge .A charge of $1.68 shall be paid for each ' 100 cubic feet of water delivered by the District. Section 3. Payment ofWaterService Payment for water service and water delivered. shall be net cash on receipt of bill. The District reserves the right to add to any bill unpaid 30 days after mailing an additional charge equal to 2% of the amount of the bill but not less than $1.00, and to add the same amount each 30 days thereafter that the bill remains unpaid. Section 4. Charge for Returned Checks If any check tendered as payment to the District is returned to the District unpaid, a charge of $20 shall be added to the payor's account. Reg.No. 1 page 1 of 2 Amended eff 1-1-92 Section 5. Reconnection of Service If a service is disconnected for non-payment of a bill a ' charge of $20 shall be paid in advance for the reconnection of the service. Section 6. Security Deposits a . A deposit with the District of cash to secure the ' payment of the District's rates and charges shall be made at the time application is made to the District for water service. b. The amount of the deposit shall be $50 or two times the estimated bimonthly bill for water service, whichever is the greater. C . The District may apply the security deposit to any account owing by the depositor to the District that is delinquent for more than 30 days. The customer shall restore the deposit to its original amount upon receipt of notice of such application. d. The security deposit shall be refunded to the customer without interest upon termination of service or at such earlier - time as the District determines that the credit of the customer is satisfactory. The customer's credit shall be deemed to be satisfactory if during 24 consecutive months recently past during ' which the customer has received water service from the District all correct invoices received from the District were seasonably paid and no more than one notice of delinquency in payment was given by the District to the customer. If after refund of the security deposit the customer 's credit shall be deemed to be unsatisfactory, the customer shall make a new security deposit within 30 days after a demand therefor is mailed to the customer. Reg-No. 1 page 2 of 2 r • REGULATION NO. 2 FIRE SERVICE Section 1. Definitions As used in this regulation the following terms have the following meanings: (a) "fire hydrant" means a standard type 611 fire hydrant; (b) "fire hydrant connection" means all the facilities from the Water District's main to the fire hydrant , including the connecting line, riser and gate valve assembly; (c) "fire hydrant assembly" means a fire hydrant and its connection; (d) "local fire district" means either the Oakley Fire Protection District or the Riverview Fire Protection District within their respective territories-, (e) "Private fire line" means a connection to the Water District's water main with a detector check assembly and extension to a private hydrant or sprinkler system by which unmetered service will be provided for the sole purpose of fighting fires and from which no other connection or use will be permitted. Section 2. Installation of Fire Hydrant Assemblies (a) Fire hydrant assemblies shall be- installed and con- nected to the Water District 's water distribution system, and may be relocated, at such times and at such locations as shall be determined by the local fire district. - Regulation No. 2, page 1 of 4. Amended 6-26-86 i �: ( b ) The installation and relocation of fire hydrant assemblies shall be done under the direction of the local fire district by a licensed contractor approved by the Water District. The installation and the materials used in the fire hydrant connection shall conform strictly to the water District 's standard specifications. The fire hydrant connection shall not be covered until it has been inspected, tested and approved by the Water District. (c ) The installation and relocation of fire hydrant assemblies shall be performed without cost to the Water District. Prior to installing or relocating a fire hydrant the local fire district shall pay, or cause the land developer to pay, to the Water District its estimate of its costs thereby incurred including engineering, supervision, inspection and administrative expenses . Upon completion of said installation the Water District will determine the actual cost thereby incurred . if the actual cost exceeds the estimated cost theretofore paid, the local fire district shall pay, or cause the land developer to pay , such excess to the Water District promptly on demand. if the actual cost is less than the estimated cost theretofore paid , the Water District shall refund the difference to the payor. Section 3. Ownership and Maintenance of Fire Hydrant Assemblies (a) The fire hydrants shall be the property of the local fire district and shall be inspected, tested, maintained, Reg. No. 2, page 2 of 4 Amended 6-26-86 repaired, painted and, as necessary, replaced by the local fire district. - (b) Fire hydrant connections shall be the property of the ' Water District and shall be inspected , tested , maintained , repaired and, as necessary, replaced by the Water District. Section 4. Private Fire Lines (a ) The Water District will provide unmetered water , service for .fire fighting to private fire lines of its customers who have separate water service connections. Said service shall , be provided at the discharge flange of the detector check assembly . The detector check assembly and the connection therefrom to the Water District's main shall be installed by the Water District in accordance with the Water District 's standard specifications provided that the Water District 's estimate of the cost thereof is paid by the customer in advance and the actual cost is paid when it is determined. (b) The detector check valve assembly and the connection thereto shall be the property of the Water District and will be operated and maintained by the Water District. The portion of a private fire line from the discharge of the detector check eck valve assembly shall be paid for, installed, owned, operated and maintained by the customer. (c) Private fire lines shall be disconnected if any water therefrom is used for any purpose other than fighting fire or for testing such service in the presence of a representative of the Water District. Reg. No. 2, page 3 of 4 Amended 6-26-86 (d ) Unmetered water service for fire fighting shall be provided at the following rates per month irrespective of the quantity, if any, of water used: Size of Detector Assembly Rate per Month 2 inches (minimum size) $ 4.00 4 inches 6.00 ' 6 inches 10.00 8 inches 20.00 ' 10 inches 35.00 Section 5. Non-Liability of District. The District shall provide water service to hydrants an.d private fire lines at such rates of flow as may be available from time to. time as a result of the operation of the Dist- ' ric.t 's treatment plant , storage facilities and distribution system. The District does not warrant or guarnatee any pres- sure, range of pressures or any rates or duration of flow. The District shall not be liable for any damage in any manner rarising .out of the non-availability of water, or water pressure at any hydrant, private fire line or other facilitiy used for fire fighting. Reg. No. 2, page 4 of 4 Reg2 Amended 6-26-86 REGULATION NO. 3 CONNECTION CHARGES AND REIMBURSEMENTS Section 1 . Charges for New Connections (a) Main Extension Charge. Each applicant for water ' service shall pay all the District's costs for necessary right of way, engineering, labor, materials, inspections, administration and overhead in any extension of the District 's facilities required by Sections 2 and 3 of Regulation No. 7. (b) Service Line and Meter. Each applicant for water service shall pay all the District's costs for necessary right of way, engineering, labor, materials, inspection, administration and overhead for installing a service line from the District's water main, a meter and a meter box for each water service. (c) Facilities Reserve Charge. Each applicant for water service shall pay a Facilities Reserve Charge determined by the size of the meter installed as follows: Size of Meter Facilities in Inches Reserve' Charge_ 5/8 $3, 063. 1 4,597 1-1/2 5,746 2 8,964 Charges applicable to larger meters shall be established by the District on receipt of application and shall be proportionally greater than those for smaller meters with consideration being given to peak flow requirements. (d) Main Extension Reimbursement Assessment. Each applicant for water service shall pay a Main Extension Reg.No. 3, page 1 of 5 Amended effective 7-1-91 Reimbursement Assessment determined by the size of the meter installed as follows: Main Extension Reim- Size of Meter bursement Assessment 58 $ 365 1 433 i-1/2 47.9 2 536 3 1 ,020 4 1 ,558 6 2,561 8 5,374 ' 10 7,082 Assessments for larger size meters will be established by the Board of Directors on receipt of application. (e) Surcharge for facilities in substandard streets. ( 1) As used herein the words "substandard street" mean a street or portion of a street in- the District that will ultimately be regraded by raising or lowering the existing surface elevation by more than 36 inches. The General Manager shall maintain a current list of all substandard streets that the Public Works Department of ,Contra Costa County determines will ultimately be regraded. (2) Whenever pursuant to section 3 of Regulation No. 7 the District solely determines that it is necessary, in order ' to furnish water service to an applicant, that a facility be ' installed in a substandard street, the District shall estimate the current cost of relocating the facility to accommodate the regrading of the substandard street. The facility shall not be installed unless and until the applicant for water service pays Reg. No. 3 Page 2 of 5 Amended effective 7-1-91 the District the amount of the estimate. (3) If' thereafter the District solely determines that the substandard street will not be regraded in the foreseeable ' future the amount of said payment shall be refunded to the applicant or his assignee without interest. (f) Payment of Charges. All charges for new connections shall be paid in full at the time water service is requested or on the due date, whichever first occurs. The due date shall be 90 days after the execution of an agreement for installation of , District facilities for water service, except that if the agreement provided for more than twenty new connections to the District's distribution system the due dates shall be as follows: 90 days after execution of the agreement, the charges for one-fourth, but not fewer than 20, of the new connections provided for in the agreement shall be due and payable; - 180 days after execution of the agreement the charges for one-third, but not fewer than 20, of the remaining new connections provided for in the agreement shall be due and payable; - 270 days after the execution of the agreement the charges for one-half, but not fewer than 20, of the remaining new connections provided ' for in the agreement shall be due and payable; - 360 days after the execution of the agreement Reg. No. 3, Page 3 of 5 Amended effective 7-1-91 the charges for all the remaining new connections provided for in the agreement shall be due and payable. The charges paid shall be those in effect on the date of payment. Section 2. EnlargementofConnections. Upon enlargement of a pre-existing connection the customer shall pay the difference between the Facilities Reserve Charge and Main Extension Reimbursement Assessment then in effect for the new meter and the amount of said charges then in effect for the meter replaced. Section 3. Reimbursements. (a) Entitlement to Reimbursement. Each person who pays the cost of an extension of the District's water distribution system (herein called the "extender") shall be entitled to be reimbursed the amount paid pursuant to subsection' (a) and (e) of Section 1 of this Regulation No. 3 without interest, less the cost of acquiring necessary right of way and less the costs of engineering, labor, materials, inspection, administration and overhead that would have been incurred for installation of facilities sufficient to serve only the extender's land. Facilities sufficient to serve only the extender's land shall be conclusively determined by the District, and in the case of pipes, shall be those in, abutting and within 100 feet of the extender's land of a size of not less than 6 inches inside diameter. Reg. No. 3, Page 4 of 5 Amended effective 7-1-91 (b) Limits on Reimbursement. The maximum entitlement to reimbursement shall be computed by the District on the basis of the maximum potential benefit to be derived by other potential users of the facilities paid for by the extender. (c) Reimbursement Payments. The District shall pay to each , extender in January of each year following the first full year after completion of the extension that portion of the total , amount of all main extension reimbursement assessments, without interest, received by the District during the previous calendar year as the extender's reimbursement entitlement bears to the ' total of all unexpired reimbursement entitlements.. (d) Expiration of Reimbursement Entitlement. An extender's entitlement to reimbursement shall expire and. become invalid upon payment thereof by the District in full or on December 31 of the tenth full year after completion of the extension. Section 4. Facilities Reserve Fund. All Facilities Reserve Charges received by the District shall be placed in the Facilities Reserve Fund. Disbursements of principal and interest of said Fund shall be made only to pay capital costs of facilities that increase the capacity of the ' District's water treatment and distribution system or the capital ' costs of relocating facilities required by a change of the grade of a street as. a result of new development. Reg.No. 3, page 5 of 5 Amended effective 7-1-91 REGULATION NO. 4 WATER METERS Section 1. Meters Required All water service connections to the District's water distri- buti on system, except fire water service furnished in accordance with Regulation No. 2, shall be metered by meters owned and maintained by the District. Section 2. Location of Meters The District's meters shall be located opposite a District water main in or immediately adjacent to the portion of the street or easement which abuts a principal boundary of the land to be served. Section 3. Each Premise To Be Metered Separately A service connection and meter will be established for each premise to which water service is provided by the District. No more than one premise shall be served through a single connection and meter. As used herein "premise" means a parcel of real property, or any dwelling unit, store or improvement thereon which the District solely and conclusively determines as a separate unit for receiving, using and paying for water service. in making said determination, the District will consider such factors as whether the premise is used for more than one enterprise or contains more than one dwelling unit, whether it is susceptible of subdivision, and the plumbing that would be required if more than one meter were installed. Reg. No. 4, page 1 of 2 Amended effective l/1/84 Section 4. Meter Readings Each meter will normally be read bi-monthly during the last week of the month, however the interval between readings may vary. Meters will also be read between 1 p.m. and 3 p.m. on days of commence- meet or termination of a service and when necessary due to special circumstances. Section 5. Meter Testings The District will test the accuracy of any of its meters whenever a customer requests and deposits with the District the District's estimate of the cost of the test. If the test discloses that the meter is registering within 2% more or less than the quanti- ties of water passing through it, the deposit will be forfeited to the District. If the test discloses that the meter is not registering within 2% more or less than the quantities of water passing through it, the deposit will be refunded and the District will repair or replace the meter. Section 6 . Adjustment for Fast Meters If the District finds that a meter has been registering fast, i.e. , indicating a greater quantity of water than actually went through the meter, the District will credit the customer's account an amount equal to the total of the two previous bi-monthly bills for the service multiplied by the percentage by which the meter was ' registering fast. This credit shall be the customer's sole right and remedy against the District for an improperlyo eratin meter. operating Reg. No. 4, page 2 of 2 Amended effective 1/1/84 i REGULATION NO. 5 TEMPORARY WATER SERVICE Section 1 . Temporary Service Connections The District shall furnish service through a temporary connection on the following conditions: (a) The General Manager determines that the service will be for less than one year and will not - require a permanent connection. (b) Prior to making the connection, the customer shall pay to the District its costs, as estimated by the General Manager, for installing and removing the connection. (c) The customer shall deposit with the District a sum of money to secure payment of the District 's charges for water delivered through the connection and any excess of the 'District's actual costs of installing and removing the connection over the amount paid in accordance with subsection (a) above. The amount of the deposit shall be three times the amount of the District's charge for water service for one regular billing period as estimated or verified by the General Manager. Section 2. Service Through Fire Hydrants Temporary service for construction purposes shall be furnished at fire hydrants through hydrant meters supplied by the District on the following conditions: (a) Service shall be limited to a specific fire hydrant for a specific construction project as stated in a written application for the service. ' t Reg. No. 5, page 1 of 2 ert,c,�riAri �_�R_on i (b ) The customer shall deposit with the District as. security for payment of the District's charges an amount to be determined by the General Manager equal to the current cost of a hydrant meter plus the estimated amount of the District's charge for the water to be delivered. (c) The customer shall return the meter to the District's office for reading, and shall pay the District 's service charges every 30 days and upon completion of the construction project. (d) The customer shall reimburse the District for its costs in replacing or repairing a hydrant meter lost or damaged while in the possession of the customer. Section 3. Charges Applicable (a) The charge for all water furnished pursuant to this regulation shall be the Quantity Charge imposed by section 2 of Regulation No. 1 . (b) The Facilities Reserve Charge and the Main Extension Reimbursement Assessment referred to in section 1 of Regulation No. 3 shall not apply to or be imposed upon temporary water service furnished pursuant to this regulation. Reg. No. 5, page 2 of 2 i REGULATION NO. 6 CONTROL OF BACKFLOW AND CROSS CONNECTIONS Section 1 . General In accordance with the requirements of the California Adminis- trative Code, Title 17, Chapter V, Sections 7583 to 7622, inclusive, no water service connection to any premises shall be installed or maintained by the District unless the public water supply is protected as required by said State Regulations and the requirements stated herein. This regulation supplements and supersedes all applicable ordinances, codes, and statutes and regulations of the Department of Health Services relating to water supply. Section 2. Where Protection is Required Backflow prevention devices shall be installed on the service connection to any premises having: ( 1) access to any auxiliary water supply, such as a well; (2) any substance handled under pressure in such fashion as to permit entry into the water system; .( 3) any material dangerous to health or toxic substance that might possible be introduced into the water system. Section 3. Type of Protection (a) Each backflow prevention device shall beofa type approved by the District and shall be installed in a location and manner approved by the District. (b) A service connection to premises having an auxiliary water supply or internal systems containing water of deteriorated quality shall be protected by double check valve assembly. Reg.No. 6, page 1 of 3 Amended effective 11-20-85 (c ) A service connection to premises handling dangerous or toxic materials such as industrial plants,. wharves, hospitals, mortu- aries, etc. , shall be protected by reduced pressure principal backflow prevention device. (d) A service connection to any sewage treatment plant or sewage pumping station shall be protected by an air-gap separation. Section 4. Installation, Inspection and Maintenance Backflow prevention devices required herein shall be installed, inspected and maintained by the District or its authorized representa- tive at the expense of the customer. Section 5. Payment of Cost of Installation Prior to the installation of a backflow prevention device the customer shall pay to the District its estimate of the District's costs, including its usual overhead charges, for purchasing and installing the backflow prevention device . After the device is installed, if the District determines that its actual costs exceed the prepaid estimate, the customer shall pay such excess promptly on receipt of a bill therefor. If the actual costs are less than the prepaid estimate, the difference shall be credited to the customer. Section 6 Annual Service Charge Each customer having a backflow prevention device shall pay a service charge therefor as follows: Meter Size Charge per Month 5/81, x 3/4" $ 0.25 J" - 0.40 1-1/2" 0.65 2" 0.90 Reg. No. 6, page 2 of 3 Amended effective 11-20-85 Meter Size Charge per Month 3" 1 .60 41, 2.20 6" 3.75 8" 5.00 10" 7.50 12"" 10.00 Reg. No. 6, page 3 of 3 Amended effective 11-20-85 REGULATION NO. 7 CONDITIONS OF WATER SERVICE Section 1 . Service Subject to District Regulations Water service shall be furnished by the District in accordance with the regulations of the District from time to time adopted or amended by the District's Board of Directors. By applying for or receiving water service from the District, each applicant or customer covenants and agrees .to be bound by and to comply with all regulations of the . District from time to time in effect. Section 2. New Services No new water service shall be connected to the District's water distribution system unless each of the following conditions are met: (a) The land to be served is within the corporate territory of the District. (b) The District solely and conclusively determines that its water treatment storage and distribution facilities, including, without limitation, reservoirs, looping mains and pumps., are sufficient permanently to provide a safe, reliable and adequate water supply to the land to be served. In determining the sufficiency of existing facilities the District may take into consideration any fact or circumstance it considers relevant including, without limitation, future water requirements of. all land to be served through the facilities, flows needed for fire fighting, and the effect the new service will have on the present customers of the District. (c) There is a District water main of adequate capacity and Reg. No. 7, page 1 of 5 Amended eff. 1-1-84 pressure in a public street which abuts a principal boundary of the land to be served. If the land to be served has no principal boundary abutting a public street, there must be a District water main in a satisfactory easement granted to the District which connects the land to be served with a public street. (d) The customer must make application for water service and pay the connection charges provided by Regulation No. 3. Applications for new service shall be in writing on forms provided by the District, signed by the intended customer or his authorized agent. Application shall be supported by such data as the District shall reasonably require, such as a map or legal description of the property to be served, -the date service is to begin, the name and billing address of the person responsible for the payment of the District's fees, charges and rates, whether such person is the owner or tenant of the property, and credit information. (e) All service lines shall be installed in accordance with the District's standard specifications. Section 3. Extensions and Enlargements of the District's Facilities (a) The design, size, type and location of all facilities necessary to meet the conditions in paragraphs (b) and (c) of Section 2 hereof shall be determined solely and conclusively by the District taking into consideration such factors as anticipated future land uses and water requirements of the entire area that can be supplied economically by the ' facilities and desirability of looping mains to provide multiple sources of water and multiple routes to move water to points of use. Mains shall Reg. No. 7, page 2 of 5 Amended 11-29-89 i be extended to the end of new street paving when such extension is required by the County or a city. (b) All extensions and enlargements of the District's facilities shall be constructed in accordance with plans and specifications approved in writing by the District's general manager or engineer prior to commencement of construction. Section 4 . Non-liability of the District , The District will exercise reasonable care and diligence to deliver to its customers a continuous and sufficient supply of water under proper pressure at the meter. However, the District is not, and will not be, liable for any loss, damage or inconvenience to any person by reason of shortage, insufficiency, suspension or discontinuance of water service or the increase or decrease of water pressure, when the same is caused by an act of God, and unavoidable accident, a disturbance or condition of any kind beyond the reasonable control of the District, or when the same is reasonably necessary for the repair, maintenance, alteration or extension of any of the District's facilities. Section 5. Customer's Responsibility for Water Delivered Title to water furnished by the District, the risk of loss thereof and full responsibility for the carriage, handling, storage, disposal and .use thereof shall pass from the District to the water user at the outlet of a District meter, the control valve of a fire hydrant of the outlet of a check valve assembly. Reg. No. 7, page 3 of 5 Amended 11-29-89 ' Section 6 . Access to Facilities By applying for or receiving water service from the District, each customer irrevocably licenses the District and its authorized employees and agents to enter upon the customer's property at reasonable times for the purpose of reading, inspecting, testing, checking, repairing, maintaining, or replacing the District's meters, backflow prevention devices, and other facilities. Section 7 . Service Interruption The District reserves the right at any and all times to shut off water delivery for the purpose of maintenance, making repairs and alterations to its system. Wherever possible, advance notice of interruption of services will be given to all water users affected. Section 8. Disconnection of Service by the District The District reserves the right to disconnect any connection to its water distribution system without notice and to discontinue water service for any of the following reasons: (a) The customer fails to comply with any of the District's regulations; (b) The service is being furnished without a proper application or under a false or fraudulent application; (c) There is evidence of unlawful tampering or interference with the District's facilities by the customer; (d) The District or a State or County public health officer Reg. No. 7, page 4 of 5 Amended 1-1-84 i finds that there exists a condition hazardous to the health and safety of the customer or any water user of the District; (e) The customer fails, after notice from the District, to remove an obstruction that prevents the reading of his meter. (f) The customer fails to pay any bill for any rate or charge of the District within 30 days after mailing or presentation, provided that written notice of intent to disconnect and discontinue service is delivered to the premise served or mailed to the customer's billing address at least 5 days prior thereto. (g) If after investigation, the State Water Resources Control Board, the California Department of Water Resources or the District finds that water. furnished through the connection is being wasted or that the use or method of use of the water is unreasonable. Section 9. Place of Use of Water; Resale Prohibited Except with the prior written authorization of the District, no customer shall use, .or permit the use of, any water furnished by the District on any premise other than that specified in his application for service, nor shall any customer resell any water furnished by the District. Section 10. Electric Grounds No electric circuit shall be grounded to the District's facilities or to any plumbing or metal in contiguity therewith. Any person who makes orP ermits to be made, such connection will be liable for damages to the -District's facilities and for personal injury resulting therefrom. Reg. No. 7, page 5 of 5 Amended 1-1-84 1 REGULATION NO. 8 WATER CONSERVATION Section 1 . Purpose The purpose of this regulation is to assure that all water furnished by the District is put to reasonable beneficial use, to prevent unreasonable use or waste of water and to promote efficient use and conservation of water. , Section 2. Prevention of Waste or Unreasonable Use All users of water furnished by the District are urged to take all reasonable action to prevent waste of water. The District shall have the right, following notice and hearing, to impose upon any water service connection such conditions as the District determines to be necessary to prevent unreasonable use or waste of water. Section 3. Conservation Measures by Customers All users of water furnished by the District are urged to take all reasonable action to conserve water. Among the actions recommended are the following: a. Periodically examine all plumbing systems to detect any leaks and repair leaks immediately upon detection. b. Prevent water from running off premises into street gutters. C. Install flow restrictors on all shower heads that will limit flow to not more than 3 gallons per minutes. d. Install displacement devices in toilet tanks to reduce water use to 3.5 gallons per flush. e . Install aerators or laminar flow devices on kitchen and lavatory faucets to reduce maximum flow to 2.75 gallons per minute. f. Landscape with minimal turf and drought-tolerant (low water-using) plants. Section 4. Conservation Measures of District a. The District shall vigorously pursue at all times a program for the conservation of water consisting in such cost-effective measures as are from time to time authorized by the Board of Directors. b. All water service, except through hydrants for fire fighting, shall be metered. C. The unit rate for all water services shall not decrease as the quantity used increases. d. The General Manager is authorized and directed to do the following:- ( 1 ) ollowing:,( 1 ) Make audits as frequently as he deems necessary of the quantities of water received by the District and the quantities of water delivered to water users in order to detect system leaks . The results of such audits shall be reported to the Board of Directors not less frequently than annually. ( 2) Distribute without charge- water-saving devices to the occupant of each building newly connected to the District's water system. 2 ( 3) Cooperate with local school districts in developing education programs on efficient water use. (4) Make available at the District 's office ; public library and other public places, printed , materials on the need for, and methods of, water conservation. Reg.8 adopted 2-26-86 REGULATION NO. 9 DROUGHT EMERGENCY REGULATIONS Section 1 . Authority and Effective Period. These regulations are adopted pursuant to section '353 of the Water Code following a determination and declaration of the Board of Directors on March 20, 1991 that an emergency condition of water shortage exists in the District. These regulations shall continue in effect until the Board of Directors . declares that the emergency has ended. Section 2. Reduction of Water Use. In order to avoid mandatory rationing of the District 's reduced water supply during the drought emergency each user of water furnished by the District is urged immediately to take the following actions voluntarily and vigorously. First, reduce the quantity of water used to the greatest extent practical. Second, eliminate unnecessary uses of water. Third, take immediate action to prevent any water from being wasted. Section 3. Prohibited Uses of Water. The following uses of water supplied by the District are determined to be wasteful and are prohibited for the duration of the drought emergency. a. Outside watering that results in excessive flooding or in runoff into a gutter or drain, or onto a street, sidewalk, Reg.No.9, page 1 of 3 Amended effective 5-22-91 Section 7. Violations. If the District finds that any provision of these regulations is not being complied with it shall notify the customer at whose premises the breach occurs. If the customer fails to take prompt reasonable action to halt the breach the District may in its discretion suspend delivery of water to the premises, and/or install a device to restrict the flow of water to the customer, until the District determines that there will be no further breach of District regulations . The costs , as determined by the General Manager, of disconnecting the service, installing a flow restrictor, and *reconnecting the service shall be charged to, and paid by, the customer. Reg.No'.9, page 3 of 3 Amended effective 5-22-91 driveway or paved area. b . Washing paved or other hard-surfaced areas , including sidewalks, driveways, patios and parking areas. c . Washing cars , boats , trailersor other vehicles without a shut-off nozzle on the hose. d. Using water for decorative fountains or for filling decorative ponds or lakes. e . Flushing sewers or hydrants or washing streets, except for emergencies,' protection of public health or safety, or. essential industrial operations. Section 4. New Landscaping. e No area in the District which was not regularly irrigated prior to April 1 , 1991 , shall be landscaped, planted or irrigated unless the landscaping plan and irrigation system makes efficient use of a minimum .quantity of water and is installed, operated and maintained in accordance with plans approved in writing by the t General Manager. Section 5. Exceptions and Waivers. Written applications for. exceptions to, or waivers of, any .provision of these regulations shall be received g and may be granted in any case where the. restriction might create a hazard to the health and safety of any individual or the public , or would cause an undue and unavoidable hardship. Section 6. Water Conservation. These regulations supplement the provisions of Regulation No. 8, Water Conservation. Reg-No-9, page 2 of 3 Amended effective 5-22-91 2 l REGULATION NO. 109 ANNEXATION OF LAND J Section 1. Law Applicable. The annexation of land to the District is governed by the provisions of the District Reorganization Act of 1965 (California Government Code § 56000, et seq. , herein cited as "the Act") . This regulation is intended to supplement the provisions of the Act and, in the event of any conflict between the provisions of the Act and this regulation, the former shall control. Section 2. Initiation of Preliminary Proceedings -by District. The District will initiate preliminary proceedings for annex- ation of land to the District if (1) evidence 'satisfactory to the District is presented that all, or a substantial portion, of the resident voters or property owners of the territory desire the annex- ation, (2) a map and legal description of the territory satisfactory to the District is filed with the District, and (3) the'proponents of the annexation agree to pay the fee herein provided. The initiation of r preliminary proceedings by the Board shall not restrict or impair the powers of the Board in subsequent proceedings for annexation of the territory or any part thereof. Section 3. Requests for Annexation. Requests and consents for annexation of land to the District and/or to an Improvement District of the District shall be on 'forms provided by the District and shall be signed by or on behalf-of all the owners of the land. Reg. No. 109, page *1 of 2 1' Amended 3/25/81 f Section 4. Fees for Annexation. (1) No territory except streets, roads and lands owned by a governmental entity shall be. annexed , to the District or to an Improve- ment District of the District unless the fees herein provided are paid. (2) The following fees shall be paid to the District by or for the owner of the land to be annexed: (a) The fee imposed by the State Board of Equalization to process the annexation. (b) The ,District's costs for preparing legal descriptions and maps in cases where satisfactory descriptions and maps have not been furnished by the owner of the land. (c) The District's costs incurred in noticing and conducting any necessary public hearing and-Jeledtion Oh.- thea annexation. (d) The District's administration, engineering and legal expenses' incurred in processing*�the annexation. Section 5. . Time and Method of Payment 'of' Feed. The General Manager shall estimate the total amount of the fees imposed by Section 4 which estimated amount shall be paid prior to initial processing of the proposed annexation by the District. Upon completion of the annexation, the General Managet shall determine the actual total amount of said fees and if the same exceeds the estimated amount thereof theretofore paid to- the District, the excess shall be paid to the District on demand. If the actual total amount of such fees is less than the prepaid estimate thereof, the difference, will be refunded. If for any reason the annexation is not completed, any excess of the prepaid estimated fees over the amount therefore expended by the District in connection with the proposed annexation will be refunded. Reg. No. 109, page 2 of 2 2. REQUEST AND CONSENT TO ANNEXATION OF LAND TO OAKLEY WATER DISTRICT Names of all owners of the land: i�. Legal Description of the Land: _ Note : Attach a legal description from deed or title policy. The assessor's parcel number or abbreviated description on tax bills is not sufficient. Map of the Area: �• Note: Attach four copies of a map showing the land to be annexed, the nearest boundary of Oakley Water District, the nearest quarter-section lines and scale. Streets and highways shall be identified. The map must meet the requirements of the -County Assessor and State Board of Equalization. If satisfactory maps are not attached hereto, ' the District is hereby authorized to cause maps to be prepared at the landowner's expense. Registered Voters: The number of registered voters residing on the land is Consent to Annexation: The undersigned owner of the land above referred to consents to the annexation of said land to Oakley Water District and agrees' -*to pay the fee for said annexation in accordance with Regulation No. 109 of Oakley Water District. The undersigned warrants that if other persons have a joint or common title or interest in said land or hold a deed of trust thereon that they have authorzied the undersigned to execute this request and consent for them and on their behalf. Dated: . i PROCEDURE FOR ANNEXATION OF LAND TO OAKLEY WATER DISTRICT General The annexation of land to Oakley Water District is governed by the Cortese-Knox Local Government Reorganization Act (Government Code Sections 56000 and following) . No land may be annexed unless and until the annexation is approved by �the Local Agency Formation Commission (LAFCO) of Contra Costa County. If LAFCO determines that land proposed to be annexed is within the District's sphere of influence and approves the annexation, the proposal must then be acted upon by the Board of Directors of the District. Request for Annexation The law permits a landowner to petition LAFCO directly for annexation. However, 'the preferred method is for the landowner to request the 'District to make the application to LAFCO. Forms, for requesting annexation and indicating the information required are available from the District. Application to LAFCO If the annexation is objectionable to the District, the General Manager will notify the landowner who may then petition LAFCO directly. Otherwise the District will request LAFCO to approve the annexation. LAFCO will notify the District and the landowner of the date of the meeting At which the request will be considered. If the annexation is approved, a copy- of the LAFCO resolution to this effect will be sent to the District. Proceedings by the District If the owners of all the land to be annexed request the annexation, LAFCO will permit the District to order the annexation without a hearing. This is done by the Board adopting a resolution of annexation and sending a certified copy to LAFCO with remittance of the fees. If LAFCO does not allow annexation without a hearing, the District shall notice and conduct a public hearing as required by law. Depending on the number of protests received, the District shall terminate the annexation proceeding, order the annexation subject to confirmation of the voters at an election, or order the annexation without an election. Costs and Fees All costs incurred by the District in processing the annexation, including the fee payable by the District to LAFCO, must be paid by the landowner as required by the District's Regulation No. 109. A copy of this regulation will be furnished on request. 2 Effective:_ LOCAL AGENCY FORMATION COMMISSION (LAFCO) OF CONTRA COSTA COUNTY Schedule of Processing Fees MAR-2 11991 The following fees apply to both City and special District Proposals: L �; Fees for applications and requests for: y't',yTER DiS Annexation, Detachment, Formation, Dissolution, Consolidation, Merger or Establish- ment of Sub?idiary District, Sphere of Influence Update: 1) 2) 5 acres or less $ 500 5+ acres 1,000 Incorporation/Disincorporation Processing (any acreage) $2,000 Comprehensive Actual cost plus 7.5% Administrative Fiscal Analysis charges -- Payable in advance State Controller's review of Actual cost -- to be determined by Comprehensive Fiscal Analysis ----------Controller -- Payable in advance ------------------------------ -------------------------------- 1) If an application affects two or more separate areas, a fee will be charged for each such area. An application to concurrently revise boundaries of two or more agencies by annexing or detaching the same area will be charged 1-1/2 times the specified acreage amount. If the same area is the subject of two or more applications to,independently change boundaries of different agencies, a fee will be charged for each such application. 2) If an application, for other than sphere of influence update, incorporation or disincorporation, requires concurrent review and update of relevant sphere(s) of influence, the processing fee shall consist of the appropriate amount according to acreage plus $350. Environmental Review Costs associated with meeting the requirements of CEQA will be charged as follows: When LAFCO is not Lead Agency: EIR Review $250 (applicant must supply 10 copies) Negative Declaration $ 50 When LAFCO is Lead Agency: Categorical Exemption: $ 50 Negative Declaration: $150 EIR Preparation Actual cost plus 25% Administrative charges -- Payable in advance Applicants shall also pay all fees imposed on LAFCO by any governmental entity, including, but not limited to, any fees assessed by the California Department of Fish & Game and the County Clerk's Office for projects requiring a Negative Declaration or an Environmental Impact Report (Public Resources Code 21089 & Fish & Game Code 711.4) Document Copying $.25 per- page Payment and Refunds Fees are due and payable at the time an application is submitted to the Executive Officer. No further action will be taken until the subject fees have been fully paid. If an application is withdrawn by,written request of the applicant within one year of being filed with the Executive Officer and before it has been placed on the Commission's agenda, the processing fee will be refunded, less $200. Waiver.Provision t The Commission may waive or adjust an application fee upon making a specific finding that the imposition of the fee would constitute a significant hardship upon the applicant, and further that the waiver would promote and further the legislative intent of the Cortese-Knox Local Government Reorganization Act of 1985. Appendix G Will Serve Letter from Ironhouse Sanitary District FAX IRONHOUSE SANITARY DISTRICT Telephone (510)625.0169 3775 Main Street,Suite E • P.O. Box 1105 • Oakley.CA 94561 (510)625.2279 June 2, 1992 Patricia E. Curtain Gagen, McCoy, McMahon & Armstrong 279 Front Street Danville, CA 94526-0218 RE: Cypress Lakes and Country Club Project Hotchkiss Tract Area Your Matter No. 02-19018/II.D. SUBJECT: Sanitary Sewer Service + Dear Patrica: The Sanitary District will provide sanitary sewer%service to the above ' named parcels subject to the following conditions: 1. Service will be provided at the" time of issuance of building permit subject to there being available treatment plant capacity. 2. Full Compliance with District Ordinances. 3. Annex to the district if property is not within the existing district boundaries. 4. Payment of all fees and .pharges at times specified in the district rules and regulations. 5. This letter is issued as an indication that the District is willing to provide sewer service but is . not to be taken as a guarantee of service in the event the District is unable to ,provide service for some unfc4csceable Tutu-re conditions or restrictions. ' Sincerely, David N. Bauer District Manager IRONHOUSE SANITARY DISTRICT DB:sp ws\cypreslk.bi . cc: tract file crop file Appendix H Cultural Resource Appendix 1 1 1 i l i 1 l 1 1 1 1 1 .1+' -•� :} ^.�" �� t�,;r •% �4�y�+�•1 1. ��1�� ��� �f.a:. 0-1 Jjr LA 4��-� �:- ►,. X00 «�' NO of Lt1. rJ i^.'i�• �.�?' • ��1j is i�F �.. � ♦"Iti S �;1� Sys �.� •''� �� � .�. .!�'2' ..row f4 7' 'i�j';:r Iwo 7�•-�..�t. �► ��;t �/ 'sem '`.�. - ^''r�' /" '"'`"'•`�"fi��.-fir: it• � _ Crin��i� a� y 'r�.:.�s'�.��• ..fir.{'•�t�-- �'T .. �� a n:•7i*.. Y..;y."+v:` ;a �� .74 "'���'�'-- ...' .T.�• (.":.�':...-... _9 .* � ; � ..,•/fir . LU TON S aLY AR � A -...••'r' •/ / /' rte/ '�•'�^1` 1 �?��_ 1� ! j ZI r ! l 0 lOb 7b0 FEET t 14 a f � tit � � /r..s' `'''�i/.fjl •j'' � _ .. - • -64 pro }�_^......._.��....��•r'M-- .+.-�--r�- 'f;��(/ � .t.7. .. -i.e •fill ''�".. `♦ g.ran '•! / .i,i �zs.' - . .61 .i.l � \ �� yam• ..._,� .7.4 •at ° \ i 16 t Figure 2. Archaeoi©gully Sensitive Area CYPRESS LAKES & (Area CCo - 647) COUNTRY CLUB PROJECT Source: William Self Associates