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HomeMy WebLinkAboutMINUTES - 09231997 - C59 C.0 !59 TO: BOARD OF SUPERVISORS, AS GOVERNING BOARD OF CONTRA COSTA COUNTY AND CONTRA COSTA COUNTY FLOOD CONTROL AND WATER CONSERVATION DISTRICT FROM: J. MICHAEL WALFORD, CHIEF ENGINEER DATE: SEPTEMBER 23, 1997 SUBJECT: DECLARE AN EMERGENCY FOR THE CONSTRUCTION OF A FLOOD WALL ALONG GRAYSON CREEK. PLEASANT HILL AREA Project No.: 7520-6139324 SPECIFIC REQUEST(S)OR RECOMMENDATIONS)&BACKGROUND AND JUSTIFICATION I. Recommended Action: 1. FIND, based on the evidence set forth below and as contained in the minutes of the Board meeting, pursuant to Public Contract Code Sections 22035 and 22050, that an emergency exists due to the projection of severe winter storms that the emergency will not permit a delay resulting from a competitive solicitation for bids, and that the action described in this order is necessary to respond to the emergency. 2. DELEGATE to the Chief Engineer the authority to proceed in the most expeditious manner to construct a flood wall along the east bank of Grayson Creek between Golf Club Road and Viking Drive. Continued on Attachment: SIGNATURE: +- _RECOMMENDATION OF COUNTY ADMINISTRATOR _RECOMMENDATION OF BOARD COMMITTEE APPROVE OTHER SIGNATURE(S): ACTION OF BOARD ON Cj-9,3-199 APPROVED AS RECOMMENDED_OTHER VO ITE OF SUPERVISORS ,/ UNANIMOUS(ABSENT ) AYES: NOES: ABSENT: ABSTAIN: MC:cI bo23a.frm 618 19 of� aentreotminutes o Board of Supe Isors on tho Cato Chown. Orig.Div: Public Works(FC Division) X1 IES IED: �3 1997 Contact: Mike Carlson 313-2311 PHIL BAT HEICR,Clerk c;±ho board / cc: Auditor Controller of Supervisors and county Administrator County Counsel D.Eckerson,Design 0,0,j P S.Mastumoto,Maintenance 49 SUBJECT: Declare an Emergency for the Construction of A Flood Wall Along Grayson Creek Project No.: 7520-6B9324 DATE: September 23, 1997 PAGE 2 3. DIRECT the Chief Engineer to make reports to the Board of Supervisors, as required by Public Contract Code 22050, stating the reasons justifying why the emergency will not permit a delay resulting from competitive solicitation for bids and why the action is necessary to respond to the emergency, in order to enable the Board of Supervisors to review the emergency action and to determine that there is a need to continue the action. 4. DECLARE that the project, as an emergency, is exempt from the provisions of the California Environmental Quality Act under Resources Code Section 15269 of the State CEQA Guidelines. 5. DIRECT the Chief Engineer to file a Notice of Exemption with the County Clerk and to arrange for payment of the $25 filing fee. 6. AUTHORIZE the Chief Engineer, or his designee, to sign on behalf of the Board of Supervisors any, and all, real property-related documents, including but not limited to right of entries, drainage easements, and temporary construction easements, as required to construct a flood wall. H. Financial Impact: There will be no impact to the General Fund. The project will be funded from Flood Control District's Zone 3B. The total cost of the improvements cannot be fully determined at this time, but staff is developing estimates to complete expeditious construction of the flood wall. M. Reasons for Recommendations and Background: The Flood Control and Water Conservation District has been preforming extensive studies of Grayson Creek and its watershed during this past year. This study confirmed many previous assumptions and also stressed the need to preform creek bank improvements along Grayson Creek to convey the design flows. The District is requesting to implement a portion of this study prior to this winter's rains. A flood wall has been proposed along the east bank between Viking Drive and Golf Club Road in the Pleasant Hill area. The Grayson Creek improvements were constructed between 1955 and 1960. During the last forty years the land use within the watershed has increased. The original channel was designed to convey a flow of 4500 cfs. Our recent study has estimated a Qioo event of 6440 cfs or about 2000 cfs greater than the original design. This is a result of higher density land uses(more impervious surfaces)than was originally estimated in 1955. The District has identified long term solutions to convey these increased flows. We have developed a preliminary estimate of twenty million dollars and require several years to construct once the money is made available. An El Nino weather pattern has been forecasted for this coming winter that could produce large amounts of rain fall. The District has identified smaller projects that can be implemented prior to these winter rains. A section of Grayson Creek, between Viking Drive and Golf Club Road, has a much lower capacity than the remainder of downstream sections. We are proposing to construct a flood wall along the east bank within this section of creek. SUBJECT: Declare an Emergency for the Construction of Coq A Flood Wall Along Grayson Creek Project No.: 7520-6B9324 DATE: September 23, 1997 PAGE 3 These improvements must be constructed prior to these pending rains to prevent the creek from overtopping in low frequency events. If the creek overtops, this could potentially damage numerous properties adjacent to the creek. IV. Consequences of Negative Action: Non-concurrence of the above recommendations will significantly and adversely delay construction of the flood wall.