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C. 1

To:	Board of Supervisors
From:	Brian M. Balbas, Public Works Director/Chief Engineer
Date:	November 19, 2019

Contra

Costa

County

Subject:

APPROVE the Marsh Drive Bridge Replacement Project and take related actions under CEQA, Concord and Pacheco areas.

APPROVE	OTHER
RECOMMENDATION OF CNTY ADMINISTRATOR	RECOMMENDATION OF BOARD COMMITTEE

Action of Board On: 11/19/2019

APPROVED AS RECOMMENDED

OTHER

Clerks Notes:

VOTE OF SUPERVISORS

AYE:

John Gioia, District I Supervisor
Candace Andersen, District II Supervisor
Diane Burgis, District III Supervisor
Karen Mitchoff, District IV Supervisor
Federal D. Glover, District V Supervisor

Contact:	Laura Cremin (925)313-2015
cc:	Laura Cremin-Environmental Services

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.
ATTESTED: November 19, 2019
David Twa,

BY:	, Deputy

RECOMMENDATION(S):

APPROVE the Marsh Drive Bridge Replacement Project (Project) and AUTHORIZE the Public Works Director, or designee, to advertise the Project, Concord and Pacheco areas. [Project No.0662-6R4119] DCD-CP#16-35 (District IV and V), and


FIND, on the basis of the whole record, including the proposed Initial Study/Mitigated Negative Declaration and any comments received and staff responses thereto, that there is no substantial evidence the Project may have significant effect on the environment, and that the Mitigated Negative Declaration reflects the independent judgment and analysis of the lead agency, Contra Costa County (County).

RECOMMENDATION(S): (CONT'D)

ADOPT the Mitigated Negative Declaration and Mitigation and Monitoring Reporting Program for the Project.

SPECIFY that the Contra Costa County Public Works Director is the custodian of the documents and other material that constitute the record of proceedings upon which the Board’s decision is based, and that the record of proceedings is located at 255 Glacier Drive, Martinez, CA.

DIRECT the Director of Conservation and Development to file a Notice of Determination with the County Clerk, and

AUTHORIZE the Public Works Director to arrange for payment of $2,354.75 for California Department of Fish and Wildlife fees, a $50 fee to the County Clerk for filing the Notice of Determination, and a $25 fee to Department of Conservation and Development for processing.

FISCAL IMPACT:

Estimated Project cost: $13,000,000.00 (88.5% Federal Highway Bridge Program, 11.5% Local Road Funds)

BACKGROUND:

The purpose of this project is to replace the Marsh Drive Bridge (#28C-0442) over the Walnut Creek Channel. The existing bridge is identified as structurally, seismically, and hydraulically deficient. The purpose of the Project is to replace the existing bridge to meet current design standards to provide safe public access.

The existing bridge was originally built as a 6-span concrete slab bridge in 1938, and was lengthened in the 1960s to a 10-span bridge. The bridge is currently 325 feet long by 34 feet wide. The new bridge will be designed to correct all of the existing bridge deficiencies and handle the seismic loads as well as the hydraulic flows within the channel. The proposed bridge replacement will be a 5-span bridge, pre-stressed concrete slab structure on concrete piles that is longer and wider than the existing bridge, at approximately 340 feet long and 55 feet wide. The existing bridge will be demolished and the new bridge will be built in stages on a raised profile approximately seven feet above existing profile with fewer supports in the channel to meet hydraulic standards.

The proposed bridge will re-align Marsh Drive slightly to the north while utilizing a larger horizontal curve on the east in order to improve safety. To improve the roadway alignment and horizontal curve at the bridge, there will be approximately 350 to 500 linear feet of roadway approach work at each end of the bridge. In its final configuration the proposed bridge will accommodate two lanes of vehicular traffic (one in each direction) with pedestrian and bike facilities on each side of the road. The Project will also include a separated path along the south side of the bridge that will tie into the existing Iron Horse Trail at the southeastern side of the bridge.

CONSEQUENCE OF NEGATIVE ACTION:

Delay in approving the project may result in a delay of design, construction, and may jeopardize funding.