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HomeMy WebLinkAboutMINUTES - 12191995 - C16 TO: BOARD OF SUPERVISORS FROM: J. MICHAEL WALFORD, CHIEF ENGINEER DATE: December 12, 1995 SUBJECT: APPROVE ADDENDUM #4 TO THE FINAL ENVIRONMENTAL IMPACT REPORT FOR THE SAN RAMON CREEK IMPROVEMENT PROJECT (Chaney to Livorna Roads), IN THE ALAMO AREA. Project No.: 7520-688562 CP#95-64 SPECIFIC REQUEST(S)OR RECOMMENDATION(S)&BACKGROUND AND JUSTIFICATION I. Recommended Action: APPROVE Addendum #4 to the Final Environmental Impact Report (FEIR), CP#95-64, (the custodian of which is the Chief Engineer and is located at 255 Glacier Drive, Martinez), DIRECT the Director of Community Development to file a Notice of Determination with the County Clerk, and DIRECT the Chief Engineer to arrange for payment of the $25.00 handling fee to the County Clerk. II. Financial Impact: Funds for the project will come from the Flood Control Zone 3B funds. III. Reasons for Recommendations and Background:. r The Addendum to the FEIR for the San Ramon Creek Improvement Project identifies some changes to the design of the improvements to the creek. The changes are as follows: 1. The project plan stations have been revised. New stations are in bold face type (e.g., Station 1 + 00). 2. Approximately 550 ft. of the east bank between Stations 2+50 and 8+00, will no longer be graded to a extent previously planned, thus preserving most of the existing vegetation. 3. A maintenance road is now proposed on the west side of San Ramon Creek between Stations 2+00 and 14+30. Gabion walls will be used to support the road where necessary. Continued on Attachment: X SIGNATURE: _RECOMMENDATION OF COUNTY ADMINISTRATOR _RECOMMENDATION OF BOARD COMMITTEE APPROVE OTHER SIGNATURE(S): ACTION OF BOARD ON j a- q_ y9s APPROVED AS RECOMMENDED_OTHER_ VOTE OF SUPERVISORS UNANIMOUS (ABSENT AYES: NOES: ABSENT: ABSTAIN: Contact: Paul Detjens, (313-2394) Orig. Div: Public Works(Design Division) cc: P. Harrington, Flood Control 1111M ecitifythatthfebatrueandeorfecteapyol P.Gavey, Real Property an action taken and entered on the minutes o�th0 Board of Supervisors on the date shown. V. Germany, Design ATTESTED: Z—�­- A A, 19 d 191� Flood Control Engineering PHIL BATCHELOR,Clerk of the Board Accounting of Supervisors and County Administrator Engineering Services County Administrator By Deputy County Auditor-Controller County Counsel . Community Development ADDENDUM#4 TO THE FINAL ENVIRONMENTAL IMPACT REPORT FOR THE SAN RAMON CREEK IMPROVEMENT PROJECT Page 2 December 12, 1995 III. Reasons for Recommendations and Background (continued): 4. Gabion walls are proposed to be used instead of pile and plate, which will eliminate the need for pile driving, a source of significant noise levels. 5. The upstream limits of the project are extended approximately 140 ft. further south. Instead of a concrete chute at the Livorna Road bridge, a transitional channel and drop structure are proposed south of the bridge. 6. Revegetation of the project area with native trees, shrubs, and grasses is part of the proposed project. The Addendum is consistent with County policies and does not lead directly or indirectly to significant physical changes in the project, nor does it alter the adequacy or the completeness of the environmental impacts and mitigation measures identified in the FEIR. In addition, none of the conditions described in Section 15162 of the CEQA Guidelines, calling for the preparation of a subsequent EIR have occurred. Therefore, an Addendum to the FEIR is appropriate to address some changes or additions to the previously certified FEIR. Upon board approval, Addendum #4 would be attached to the FEIR for the San Ramon Creek (Chaney to Livorna Roads) Improvement Project. IV. Consequences of Negative Action: Delay in approving the project and the Addendum to the FEIR will result in delay of construction of the project. VG:mat cAsanramoMaddenbum.4bo Please refer to: the San Ramon Creek Improvement Project (Chaney to Livorna Roads) Draft Environmental Impact Report, Comments and Responses, Addendum #1 , and Addendum #2 previously submitted May 2, 1995, and Addendum #3 submitted October 17, 1995. t..- ADDENDUM #4 to the FINAL ENVIRONMENTAL IMPACT REPORT (FEIR) for the SAN RAMON CREEK IMPROVEMENT PROJECT CHANEY ROAD to LIVORNA ROAD County File #PW 85-55, CP #92-84, CP # 95-29, and CP #95-58 CP# 95-64 Prepared by: Maureen Toms, Planner Contra Costa County Public Works Department 255 Glacier Drive Martinez, CA 94553-4897 November 1995 nvironmental Planner (Chief Planning Official) Public Works Department Title: Lead Agency: County of Contra Costa i Date: Az/ ADDENDUM #4 to the FINAL ENVIRONMENTAL IMPACT REPORT (FEIR) for the SAN RAMON CREEK IMPROVEMENT PROJECT CHANEY ROAD to LIVORNA ROAD County File #PW 85;55, CP #92-84, CP # 95-29, and CP #95-58 CP# 95-64 Prepared by: Maureen Toms, Planner Contra Costa County Public Works Department 255 Glacier Drive Martinez, CA 94553-4897 November 1995 ADDENDUM #4 to the FINAL ENVIRONMENTAL IMPACT REPORT (FEIR) for the SAN RAMON CREEK IMPROVEMENT PROJECT CHANEY ROAD to LIVORNA ROAD County File#PW 85-55, CP #92-84, CP # 95-29, and CP #95-58 CP# 95-64 PREFACE The Draft and Final Environmental Impact Report .(DEIR and FEIR, respectively), which includes Addendums #1, #2, and #3 evaluated the proposed project which involves the construction of an earth and rock-lined channel between Chaney and Livorna roads in the Alamo area of Contra Costa County. . This document serves as Addendum #4 to the FEIR for the San Ramon Creek Improvement Project (County File #PW 85-55, CP#92-84, CP#95-29, and CP#95-58). Consequently, the FEIR for,the project consists of the DEIR, comments received on the . DEIR, responses to the comments raised, and Addendums#1 -#4. The Contra Costa Community Development Department (CDD) is the lead agency for the project, and on June 16, 1987, the Board of Supervisors (Board) as the Governing Board for the Contra Costa County Flood Control District (FCD) approved the project and filed a Notice of Determination with the County Clerk. The Board acknowledged that the project would have certain _environmental effects and adopted the findings and mitigation measures as expressed in the San Ramon Valley Regional Planning Commission Resolution No. 20-1987. The Resolution was certified on 27 April 1987. In addition, the Board recognized that impacts such as future land use and hydrology; traffic and circulation; water quality; wildlife and vegetation; geology, soils, and earthwork; noise; air quality; cultural resources; and growth inducement, would only be partially mitigated or not mitigated in Resolution No. 87/364, June 16, 1987. Addendum#1 (approved January 12, 1993) identified the need to acquire the property at 1452 Paseo Nogales, Addendum #2 (approved May 2, 1995) identified the need to acquire property at 1411 Livorna Road, and Addendum#3 (approved October 17, 1995) identified the. need to acquire property at 27 Glade Lane. 1 CEQA PROCESS The California Environmental Quality Act (CEQA) prescribes that an Addendum (CEQA Guidelines Section 15164) to a previously certified environmental impact report (EIR) shall be prepared by either the lead agency or the responsible agency if some changes or additions are necessary but none of the conditions described in CEQA Guidelines Section 15162 have occurred: 1. No substantial changes are proposed in the project which will require major revisions of the previous EIR ... due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects; 2. No substantial changes with respect to the circumstances under which the project is undertaken which require major revisions of the previous EIR ... due to the involvement of new significant effects or a substantial increase in the severity of previously identified significant effects; or 3. No new information of substantial importance shows that the project will have one or more significant effects not previously discussed, nor will mitigation measures or project alternatives previously examined be substantially more severe than previously shown. In addition, there is no new information showing that mitigation measures or alternatives previously found not to be feasible would in fact be feasible, and would substantially reduce one or more significant effects of the project, and there is no such new information suggesting that new mitigation measures or alternatives which are considerably different from those analyzed in the previous EIR would substantially reduce one or more significant effects on the environment. In accordance with CEQA Guidelines Section 15164(d), the Board shall consider Addendum #4 along with the FEIR prior to making a decision on the project. According to CEQA Guidelines Section 15164 (c) an Addendum does not require circulation for public review but can be included in or attached to the FEIR. As noted in the Preface, Addendum #4 is attached to the FEIR for the San Ramon Creek Improvement Proiect (County File#PW 85-55, CP#92-84, CP#95-29, and CP#95-58). EXPLANATION OF ADDENDUM #4 Addendum#4 to the FEIR for the San Ramon Creek Improvement Project identifies some changes to the design of the improvements to the creek. The changes are as follows: 1. The project plan stations have been revised. New stations are in bold face type (e.g., Station 1 + 00). 2 2. Approximately 550 ft. of the east bank between Stations 2+50 and 8+00, will no longer be graded to a extent previously planned, thus preserving most of the existing vegetation. 3. A maintenance road is now proposed on the west side of San Ramon Creek between Stations 2+00 and 14+30. Gabion walls will be used to support the road where necessary. 4. Gabion walls are proposed to be used instead of pile and plate, which will eliminate the need for pile driving, a source of significant noise levels. 5. The upstream limits of the project are extended approximately 140 ft. further south. Instead of a concrete chute at the Livorna Road bridge, a transitional channel and drop structure are proposed south of the bridge. 6. Revegetation of the project area with native trees, shrubs, and grasses is part of the proposed project. Addendum #4 is consistent with County policies and does not lead directly or indirectly to significant physical changes in the project, nor does it alter the adequacy or the completeness of the environmental impacts and mitigation measures identified in the FEIR. Therefore, Addendum #4 to the FEIR is appropriate. ADDITION TO THE FEIR This section identifies the language which is added/or changed (bold face type) or deleted (strikeout) to the text and figures of the FEIR (as revised by Addendums#1 -#3 where indicated *): p. 1, 1 st paragraph, 2nd sentence: It consists of drainage channel improvements to an approximate 3,350 3,500-foot reach of San Ramon Creek. 2nd paragraph, 4th sentence: The improvements extend south to a point approximately 4-50 290 feet south of the Livorna Road Bridge. 3rd paragraph, 1 st and 2nd sentences: The planned improvements are presented in Figures 3,4 and 5 3a, 4a and 5a at a scale of 1 inch = 80100 feet. The base map for these plans is a 1985 aerial photograph topographical map that shows existing cultural features, vegetation, and topographic contours (Note: Stationing for the project has been revised). p. 4, 1 st paragraph, 3rd and 4th sentences: The proposed design provides for a 6 - 8-foot drop in elevation at the Livorna Road via a concrete-chtrte-drop structure. Immediately downstream of this cc—teidhute, a eonerete lined stilling basin proposed to The drop 3 structure would dissipate energy, thereby slowing the velocity of runoff. Below the stilling basin drop structure, the channel would have a uniform gradient of approximately 0.1% to 0.2%, and the floor of the channel would be several feet lower than and 20 feet ± to the east the existing channel. p. 4, 2nd paragraph, 1 st sentence: In general, the top of the west bank is to be retained in its existing condition, to the extent possible . 5th sentence: Where the channel is constricted, and an earth channel is not feasible, a permanent retaining wall is proposed on the west side on the banks at various reaches of the improvements (pile and pfate gabion baskets). p. 9, 1st paragraph, 2nd, 3rd and 4th sentences: These sections, which are labeled AN through W FF' are presented in Figures 6a and 7a at a scale of 1"=88'40' and are the sarne scale as the Improvement Plans. Areas of the proposed cut and-fill-are represented by the area between the dashed lines(representing the existing toporaphy) and the solid lines (representing the proposed improvements) a parallel 'one pattern and fill areas are represent ,. by a dot pattern. The water surface elevation for the future t during peak diseharge ffern the 100 year flood, is represented by the tip of a triangle. 2nd paragraph, 1 st sentence: The sections extend from near the downstream end of the project (AN) to the Livorna Road bridge (KK FF'). 3rd paragraph, 1st through 8th sentences: With regard to the sections-�ad elsewhere an the DER), all referencing to stations pertains to the revised stationing in along the u n center"ne. Thas 'One extends from Stateen 04 00 at the downstreamend of the projeet to Station 33 @ 50 at the upstrearn end of the project. It should alse be noted that-the floor of the existing ehannel is not aeeurately portrayed on the Seetions. the water swrftsee elevation on 10 isnuary 1985. Aerial photographs of the projeet area were taken on that date. t photographs, ere ared the hie t bridge,the floor of'Uh- ehanne' Os 1 to 3 feet 'ewer than the seetoons indocated. ' lowever, in some areas the floor of the ehannel is 8 or 10 feet lower than the seetmens indoeate (e.-T. under the Chaney water depths exeeed 8 feet). rIVVI VI U IQI 11 30 will 14 d 22 IIGL in verties! height. The seetion indieates that the depth of proposed etit 4 feet below floor of the channel. I lowever, the project would not reduce the fail elevation of the tsorevetment, or any other type of banpmteetiont would be required. The existing grouted roek will be retained on the upperportion of the=east buc-21-11K. 5th paragraph.- SEOTION BB' (Station 3+45) shows a modified trapezoidal channel4 that has a 34-foot beftem width and 21 embankments. The ficedway has an elevat .; . There is no rock protection in thi- �pt that w�ieh exios on the papst bank. p. 10, 1 st paragraph: Seetoon 60' (Stafign 61 leeated at the north t�rm*nus of a Pile and plate we". This wall defines the south t of the floodplain shown in Seetion 1313'. The wall is proposed as a practies! means of providing a hydraulie design that can earry runoff through the projeet area, and at the same tome, avoid the need to acquire right of- way at the expense of the developed residential let at the terminus of Sunnybreek Read-. The we'! !Aely 2-4 feet east of the top of-b 2nd paragraph: Section DD'AN (Station 49+5211+00) shows a trapezoidal earth channel with a 2:1 embankment on the west bank and 1-1/21 on the east bank. The bottom width of the channel would be 30 approximately. 35 feet. Where sandstone bedrock is exposed in the cut slope, no special engineering measures would be required to control erosion. Where alluvial soil is exposed on the east bank, gabion mats or other revetment rock would be used to control erosion. 3rd paragraph: Section E-F BB' (Station 44+4315+00) shows a-trap gabion-lined channel with a narrow maintenance road on the east bank. The channel would have a bottom width of 22 approximately 44 feet with embankment possessing a gradient of 34 2:1 above the gabions. The effect of the planned improvements would be to shift the centerline of the floor of the channel by approximately 3015 feet to the east and lower the floor of the channel by approximately 4--9 7 feet. The existing top-of-bank on the west side of the channel is elevation +224 feet. The pertion of this bank that is a elevation i 210 feet w:" not be modified by the met 4th paragraph: Section IFF (Station with a Rom width of 16 feet, and a floodplain on the east bank at ele�ation +205 . The west bank has a slope gradient of 31: the east possesses gradients of . - Jepth of eu is approximately 25 feet. Like seetion EE', the upper portion of the west bank would be retained natural condition. 5th paragraph: . The seetion shows a 504bot high fill slope that possesses a slope gradient of : , and with drainage terrsees at 25 feet vertieal intervals. The shoulder of Interstate 680 is leeat mrnedoate'y east of this seefion. p. 12, 1 st paragraph: Section GG' CC' (Station 2-1++76 22+00) indicates that the creek a bypass channel would be realigned constructed approximately 80 feet east of its the present channel location. The existing channel would be retained in its existing condition and serve as a floodplain low flow channel. The floor of the ehannel would be at. elevation +2eE) feet. 2nd paragraph: Section HK DD' (Station 24+06 26+20) shows the floor of the 5 channel is to be shifted 29 30 feet to the east and is to be approximately 7 5 feet lower than the existing channel. The toe of the existing oversteepened west bank will be extended outward by backfilling the bank with rubble or other suitable fill, resulting in a gentler slope. The west bank is to be gabion m The portion of the west bank above the gabfen mat fill will be retained in its existing condition and remain in private ownership. , slong with a maintenance read vati�n i i20 feet. The eut slope�6verlooking the rha.intenanee read would be 70 feet high, possess a gradeent of 21 and drainage terreee at 25 feet vertweal intervals. The existing maintenance road will be relocated approximately 35 feet downslope. 3rd paragraph: Section J& EE' (Station 39+f6 31+00) shows a gabion and rock lined channel with a 35 foot bottom width seeflon immediately downstrearn from the s#�tng-basin. Above the gabions, Tthe channel embankment would have a gradient of 1-1/2:1 and be lined with boulders to protect banks from erosion. A 12-foot high retaining strueture iS PFOposed on the east bank. The top-of-bank on the west side of the ehan Would be shifted appmximately 10 feet to the west. Maintenance roads will be at the top-of-bank on each side of the channel. The east bank maintenance road will also serve as a driveway for the existing residence on Glade Lane. 4th paragraph: Section KK FF (Station 39+9.7 33+00) shows a section through the proposed concrete stilling basin under the Livoma Road Bridge,just downstream of the proposed drop structure. The floor of the stilling basin would be approximately 4-2 7 feet below the existing channel elevation. The embankment would possess a gradient of 1-1.. The west bank would be 3.3 feet high-. p. 44, item C. 1. a.: enlarging the,channel by excavation of ah,. east (widening) item C. 1. d.: increasing,the flow velocity south of and under the Livoma Road bridge (drop structure) p. 46, 1 st paragraph, 2nd sentence: By limiting the work to the east on both banks to that which is necessary, only one of the-sides the minimum amount of the creek banks will be stripped. The new east bares slopes will vary between 1:5:1.0 (horizontal to vertical, respectively) and 3.0:1.0, depending on the bank material and whether or not slope protection is used. 2nd paragraph, 4th sentence: The capacity was increased by use of a concrete ehute and stilling be drop structure and channel to accelerate the fle under the bridge. This structure will also dissipate energy and minimize erosive velocities in the downstream channel. . 3rd paragraph, 2nd sentence: The creek should revegetate with time. Revegetation of the project area is part of the proposed project. 6 p. 53, 1 st paragraph, 4th - 8th sentences: The proposed project calls for constructing a concret drop structure south of the bridge and a concrete channel under the bridge. Thisese structures would increase the cross- sectional area of the channel at the bridge, and would speed the velocity of runoff through this reach of the project. The concrete chute drop structure is a key feature.of the project. It permits retaining the existing bridge, lowers the channel gradient downstream from the Livorna Road bridge (reducing the erosion hazard); and lowers the elevation of the floor of the channel downstream from the Livorna Road bridge trees at the top of the west . During construction of the concrete ehute drop structure, flagging traffic on Livorna Road may be necessary. p. 55, Table V.: 2. Delivery of Rock 298 222± (truck capacity 15 cu. yds) 7. 8 40 foot lengths) 8: Gabion Cages (4,200 lineal feet) 412 p. 71, 7th paragraph, after 4th sentence: Alternatively, the excavated earth may be hauled off-site to and upland fill site. If an upland fill site is used, the fill sites described below will be reduced in size or eliminated. The'fill sites east of the channel, along with the status of negotiations that will affect property owners are described below: p. 95, 4th paragraph, 1 st sentence: Because of the eMate drop structure at the Livorna Road bridge, the creek gradient downstream from the drop structure will be lower than the existing gradient, and the veloeities will be lewe,r. p. 98, item E., 1. Impact: AN-eExisting vegetation and the wildlife habitat it provides,would be removed by grading activities within the proposed improvement areas, except for areas identified on the final plans to be preserved. TABLE XIV. SUMMARY OF VEGETATION TO BE REMOVED LOCATION DESCRIPTION OsOOTO A riparian and most upland vegetation within graded area.- Access road to Collie Could cause removal of several large valley oaks. Fill would also Craig Bridge impact plant populations associated with sandstone outcrops NW of Station 9+9A the northern project limits. 7 TABLE XIV Continued Northern F*k%ea 1,000 fineal foot segrnent of landseeping along western edge of West bank-,-2+00-to Row of young redwoods rerneved 6+8@ Stations 1+00 to Remove approximately 19 of the 67 trees along the west bank. 8+50 Species include oak, walnut, pine, willow clumps, almond, poplar, cedar, and redwood. Stations 8+30 to Remove approximately 15 of the 22 trees. Species include oak, 11+70 poplar and pine. Two poplars are on the east bank and the remainder of the trees are on the west bank. Cut slepe-&Ia�� Eliminate much oak s Iuding seven live and valley eak's. bank, Stafien 9,50 1- X3+5@ West bank,--Stafton Row of 5-year eld pine and decdor eeder immediately acqaeent to pile 10 150 to 1-2 N A and plate wall. Thesewill not necessarily be removed. If se, would be replaced with 1 yeatokl4fees Stations 11+70 to Remove approximately six of the 12 trees. Species include 14+40 poplar and redwood. Trees to be removed are on the west bank. East benkT-Statton Riparian wood'and vegetation would be removed 13+@8-to�3+@@ West bank,--S� Ouster of large Fremont cottonwood is on perimeter of, graded a 14+5@ Stations 14+40 to Remove approximately 14 of 38 trees. Species include willow 18+20 clumps, bay, cypress, and poplar. All trees to be removed, except the cypress, are on the west bank. Area between ereek A" vegetation, ineluding numerous oaks, cottonwood, ash, , and 1-680 11 along with Monterey pine in th6 Galtrans right of-wery'.- 13+@0 ted@+@@ Stations 18+20 to Remove approximately seven of 34 trees. Species include3 22+00 poplar and oak on the west bank, and eucylptus and oaks on the east bank. Stations 22+00 to Remove approximately four of the 24 trees. Species include 25+00 poplar, eucylptus, and oak on the west bank. 8 TABLE XIV Continued savanna,Lower portion of AH vegetation, including willow thickets, remnants of oak bank and east ban't and large eueslyptus a! Station 28 4 00. Also includes trees located Station 2.3.,IS 0 t WA within 1-680 right of-way. 33+00 Stations 25+00 to Remove approximately four of the 20 trees. Species include 28+00 poplar on the east bank, and buckeye and willow clumps on the west bank. Stations 28+00 to Remove approximately 15 of the 22 trees. Species include 30+00 buckeye and poplar from the west bank, and buckeye, oak, and eucylptus on the east bank. Stations 30+00 to Remove approximately nine of the 22 trees. Species include oak 33+00 on the west bank, and oak, walnut, poplar and willow clumps on the east bank. Stations 33+00 to Remove approximately 31 of the 86 trees. Species include 38+00 almond, cottonwood, and oak from the east bank, and buckeye, bay, redwood, cedar, pine, and oak from the channel to west bank area. An ornamental on the east bank will also be removed. Pertains to the stationing along the " " centerline p. 100, 4th paragraph, 3rd sentence: The use of.a concrete channel along the creek has been restricted to a 200 foot segment at the Livorna bridge under crossing. Gabion gats walls are proposed along the western edge both sides of the creek from Station 23+00 to 31+80 29+00 to 32+00. p. 103, 3rd paragraph, 3rd and 4th sentences: Equipment to be used onsite may include pile , loaders, bulldozers, diesel trucks, cranes, and possibly scrapers, and water trucks and other various construction equipment. Individual sources of noise are}rife dreg, engine related noise (cooling fan and exhaust/muffler), and wheel noise. p. 103, 4th paragraph, 2nd sentence: Pile driving-wou'd resu't in even higher levels: p. 104, 5th paragraph, 1st sentence: A reasonable target for construction equipment noise is a maximum of 85 dBA at 50 feet. p. 106, item 4: ,Noise intrusion, especially during pole driving. 9 p. 110, item C, 2nd sentence: I lowever, Me proposed project doesnotincludes a plan for revegetation of the areas disturbed by grading, and no specific measures are included to preserve native trees on the perimeter of graded areas. 10 RESOLUTION of the SAN RAMON VALLEY REGIONAL PLANNING COMMISSION, STATE OF CALIFORNIA, INCORPORATING FINDINGS and RECOMMENDATIONS PERTAINING to the FINAL ENVIRONMENTAL IMPACT REPORT for the SAN RAMON CREEK FLOOD CONTROL PROJECT between CHANEY and LIVORNA ROADS RESOLUTION NO. 20-1987 The Findings for the San Ramon Creek Flood Control Project between Chaney and Livorna roads were made by the San Ramon Valley Regional Planning Commission to comply with Section 15091 of the CEQA Guidelines and are incorporated herein by reference. 11 CONTRA COSTA COUNTY ADDENDUM #4 FINDINGS for the FINAL ENVIRONMENTAL IMPACT REPORT for the SAN RAMON CREEK FLOOD CONTROL PROJECT between CHANEY and LIVORNA ROADS The following information is added to the findings prepared for the previous EIR and is presented to comply with Section 15091 and 15164(e) of the CEQA Guidelines for the FEIR for the San Ramon Creek Improvement Proiect. 1. Environmental Effect: Modifications to the project, including the proposed drop structure upstream of the Livorna Road bridge are not substantial changes to the project and will not result in any additional environmental effect not previously discussed. The revisions to the project include localized solutions, thus they are more sensitive to the environment, requiring the removal of less vegetation than the previous plan. Revegetation of the project area is part of the proposed project. Findings: There are no significant environmental impacts associated with the changes or additions to the project description for which Addendum #4 was prepared. The Draft EIR states that "alternative design approaches should be considered to reduce the extent of grading... and to alleviate the potential impacts to the oak savanna in the area." Addendum#4 describes these approaches which reduce the extent of grading and the potential impacts to the oak savanna. Furthermore, the minor changes to the plan incorporate many of the mitigation measures recommended in the EIR. Statement of Facts: a. The project to be developed pursuant to Addendum #4 to the FEIR for the San Ramon Creek Improvement Proiect is substantially similar to the project analyzed in the FEIR. b. The FEIR for the San Ramon Creek Improvement Proiect consists of the DEIR, comments received on the DEIR, responses to the comments raised, and Addendums#1 -#4. The FEIR was completed in compliance with the CEQA. c. There are no substantial changes, pursuant to CEQA Guidelines Section 15162 (a)(1), in the project which require major revisions of the FEIR due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects. The project is substantially similar to the project analyzed in the FEIR. d. There are no substantial changes with respect to the circumstances, pursuant to CEQA Guidelines Section 15162 (a)(2), under which the San Ramon Creek Improvement project is undertaken which require major revisions of the previous 12 EIR due to the involvement of new significant environmental effects or a substantial increase in the severity of previously identified significant effects. Those circumstances remain substantially similar to the circumstances analyzed in the FEIR. e. There is no new information of substantial importance, pursuant to CEQA Guidelines Section 15162 (a)(3), which..shows that the project will have one or more significant effects not previously discussed, nor will mitigation measures or project alternatives previously examined be substantially more severe than previously shown. In addition, there is no new information showing that mitigation measures or alternatives previously found not to be feasible would in fact be feasible, and would substantially reduce one or more significant effects of the project, and there is no such new information suggesting that new mitigation measures or alternatives which are considerably different from those analyzed in the previous EIR would substantially reduce one or more significant effects on the environment. f. None of the conditions calling for the preparation of a subsequent or supplemental EIR have occurred (see items 1 .c - e above). Therefore, it is appropriate to adopt Addendum #4 to the FOR to make some minor changes to the project description (CEQA Guidelines 15164). Addendum #4 shall be considered along with the FEIR prior to the Board making a decision on the minor changes to the project, and in considering the minor changes, the Board is considering the identical or substantially similar underlying project. The findings are supported by substantial evidence in the administrative record'and are based on the FOR for the San Ramon Creek Improvement Proiect which was subject to public review. In accordance with CEQA Guidelines Section 15164(d), the County Board of Supervisors shall consider Addendum #4 along with the FEIR prior to making a decision on the project. According to CEQA Guidelines Section 15164 (c) an Addendum does not require circulation for public review but can be included in or attached to the FEIR. As noted in the Preface, Addendum #4 is attached to the FEIR for the San Ramon Creek Improvement Project (County File#PW 85-55, CP#92-84, CP#95-29, and #95-58). 13 t •9 �i4 .� ............. Oz �► ra Om )44 'aONJ r Y + WO �1A s � his• C �✓ "�tq � �•c 7� ��1s �(5 0 i 0 Z r �Rd •th�J aoo � NJ* >m. : p m .00 Z Z n m • / O Qa �ry its e v SUNNYBRQOK RD e y • Iil .. 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O - P ..A 4 n �3 M �g �o c a FIGURE 6a r ll 1-680 /1 Z LLI W MA114TENANCE ROAD _41r i i i p i to p n s ra Dv p rov rto /b lry /So /m r7o STATION 11+00 (LOOKING NORTH) i B J B' MAINTENANCE o �_ l ROAD ui STATION 15+00 (LOOKING NORTH) C C' MAINTENANCE Zb ROAD W ---- ----------- WLro - - -- -- -- -- EXISTING CHANNEL BYPASS CHANNEL e p se N ♦e S 60 'A pr rp M /Lo rb /a /SO � IN Ko IA loD Lo jL0 LSD Lr0 ZSD STATION 22+00 (LOOKING NORTH) CONTRA COSTA COUNTY FLOOD CONTROL AND WATER CONSERVATION DISTRICT SAN RAMON CREEK IMPROVEMENT PROJECT SCALE- 1"=40' FIGURE 7a :D D' 1-680 EXISTING !% MAINTENANCE - NEW ROAD MAINTENANCE Z._ ROAD RUBBLE FILL WITH SOIL COVER Z- §ui5 ------ -- �o W - -- 7N- n 7� M 9 v a lm /Eo /30 5ro /b fro Im Ib zoo 210 STATION 26+20 (LOOKING NORTH) E' E `'`•`40 .�' O ' =MAINTENANCE �MAINTENANC ROAD .-ROAD/DRIVEWAY Q - _ J W . Y M 50 d 'D W b CO Iro Z ry0 w0 IID Ib /Ip /DO F F' STATION 31+00 DANVDOWNSTREAM OF LIVORNA ROAD BLVD. LE (LOOKING NORT BLVD. . 1-680— M SK— ip— Z _ _ O 2v- F- '�- Lu W =7- -- � 10 D 5� b SO Ltl 'P /m Iq STATION 33+00 (LOOKING NORTH) CONTRA COSTA COUNTY FLOOD CONTROL AND WATER CONSERVATION DISTRICT SAN RAMON CREEK IMPROVEMENT PROJECT crnl r-- 1,/=An, CALIFORNIA ENVIRONMENTAL QUALITY ACT NOTICE OF DETERMINATION CONTRA COSTA COUNTY COMMUNITY DEVELOPMENT DEPARTMENT 651 PINE STREET 4TH FLOOR NORTH WING MARTINEZ,CAIJFORNIA 94553-0085 Telephone: 510 313-2296 Contact Person:Vickie Germany,Public Works Dept. Project Description, Common Name (if any) and Location: SAN RAMON CREEK IMPROVEMENT PROJECT - ADDENDUM #4, COUNTY FILE #CP 85.64: This is addendum #4 to the FEIR forte San Ramon Creek Improvement Prole et identifies some changes to the design of the improvements to the creek. The changes are as follows: 1. The project plan stations have been revised. New stations are in bold face type(e.g.,Station 1 +00) 2. Approximately 550 ft. Of the east bank between Stations 2+50 and 8+00, will no longer be graded to a extent previously planned,thus preserving most of the existing vegetation. 3. A maintenance road is now proposed on the west side of San Ramon Creek between Stations 2+00 and 14+30. Gabion walls will be used to support the road where.necessary. 4. Gabion walls are proposed to be used Instead of pile and plate,which will eliminate the need for pile driving,a source of significant noise levels. 5. The upstream limits of the project are extended approximately 140 ft.Further south. Instead of a concrete chute at the Uvorna Road bridge,a transitional channel and drop structure are proposed south of the bridge. 6. Revegetation of the project area with native trees,shrubs,and grasses Is part of the proposed project. Addendum#4 is consistentwith County policies and does not lead directly or Indirectly to aignifieant physical changes In the project,nor does It alter the adequacy or the oompletenam of the environmental impacts and mitigation measures identified in the FEIR. Therefore,Addendum #4 to the FEIR is appropriate. The project was approved on Pursuant to the provisions of the California Environmental Quality Act An Environmental Impact Report was preparers and certified. The Project was encompassed by an Environmental Impact Reportp�feviousl prepared for the the San Ramon Creek--Chaney Road to Livoma Road.County File ftCP 85- 5(,Januar 1985)_ 1...^—1 A Negative Declaration was Issued Indicating that preparation of an Environmental Impact Re ort was not required. P eq Copies of the.record of project approval and the Negative Declaration or the final EIR may be examined at the office of the r^Contra Costa County Community Development Department. L..LJ The Project will not have a significant environmental effect l J The Project wlll have a significant environmental effect Mitigation measures were made a condition of approval of the project. Astatement of ovefridng considerations was adopted. Findings were adopted pursuant to Section 15091 of the State CEQA Guidelines. Date: By: Community Development Department Representative AFFIDAVIT OF FILING AND POSTING 1 declare that on I received and posted this notice as required by California Public Resources Code Section 21152(c). Said notice will remain posted for 30 days from the filing date. S nature Title Applicant: County Public Works Department 255 Glacier Drive Martinez,CA 94553 Attn:Janet Frattini County Clerk Fee Due-$25