The Byron Highway Bridge was initially constructed in 1965 by the Department of Water Resources (DWR) in agreement with Contra Costa County (County). The 1965 agreement (County Road Modification Agreement) defined DWR as the responsible party for the structural portions of the bridge and County as responsible party for “all other portions of such bridges, such as roadway surface of deck, curbs, sidewalks, lighting facilities, guard rails, highway markings and traffic signs.” In 1975, another agreement was signed by the County and DWR, “Consent to Common Use Agreement,” which defined an area of common use where the County roadway (Byron Highway) intersected with DWR’s Aqueduct. This area of intersection measures approximately 50’ wide by 1200’ long and the agreement further defines how the County and DWR interact on various operations and maintenance issues within that area.  
  
The Bridge began having structural issues in the mid 1990’s with deck cracking. In 1995, the County and DWR participated in a joint project to rehabilitate the existing bridge by providing maintenance upgrades to the structure. The County was lead agency on this federally funded project. In 2000, DWR in collaboration with the University of California at San Diego, provided a bridge rehabilitation project to address severe deflections in the bridge structure due to traffic loads. DWR paid for this project without County assistance. In early 2003, DWR led an emergency project to install improvements to the structure, including a series of supplemental supports under the bridge. Again, DWR carried the financial responsibility for this project.  
  
The 2003 work is considered temporary, so although the bridge is open to all legal loads, it has a low sufficiency rating in the California Department of Transportation (Caltrans) bridge inspection program and is eligible for federal bridge replacement funds. DWR initiated a bridge replacement project in 2006 - 2007 with Caltrans, but soon discovered that a state agency was not eligible to receive federal bridge replacement funds, so they have requested that the County be the “face” of the project to make it eligible to receive federal funds through the Highway Bridge Program (HBP). The County has agreed to participate with DWR in the project to replace the structure.  
  
Caltrans is the agency that is responsible to the Federal Highway Administration (FHWA) for administering the federal-aid programs, which includes the HBP. All project submittals go through Caltrans for review and approval.  
  
On June 28, 2010, Caltrans issued an authorization document (E76) which authorized the County to begin Preliminary Engineering for the project. On November 15, 2010, the County and Caltrans executed a Program Supplement Agreement No. N055, which binds the County to certain conditions for accepting federal funds for the project.  
  
On July 9, 2013, the County Board of Supervisors approved Cooperative Agreement No. 353147-E between DWR and County.  
  
The basic concepts of Cooperative Agreement No. 353147-E between County and DWR:  
  
1. DWR performs the project tasks; County acts in an oversight role, except for right of way acquisition where County takes the lead role.  
2. County pays for the local share of the County’s oversight costs; DWR pays for the local share of all other project costs and the federally non-participating project costs.  
3. The agreement follows the same format as the 1965 County Road Modification Agreement which is the Cooperative Agreement format.   
  
In May 2015, Caltrans Local Assistance made the finding that the Cooperative Agreement No. 353147-E between the County and DWR was not in alignment with the Caltrans Local Assistance Procedure manual and would need to be revised for the project to remain eligible for HBP funds. The main issue was that the County was not found to be established as in responsible charge. Caltrans Local Assistance later made the finding that the majority ownership of the structure needed to be with the County. The pathway forward was to revise the Cooperative Agreement to establish the County in responsible charge of the project and majority owner of the bridge. This put the project on hold until the project team could be reconstituted with the County in responsible charge.  
  
In 2017, the County in coordination with Caltrans and DWR made a joint decision that DWR would transfer all of the preliminary design efforts (design and environmental clearance) to the County. The decision also included putting the County as lead for right of way engineering and the entire construction administration phase. DWR was reduced to simply an oversight role. Cooperative Agreement No. 353147-F was then prepared to memorialize these decisions.  
  
Recent project milestones:

• September 11, 2018: County hires Drake-Haglan and Associated (now Dewberry) to provide consultant design and environmental services for the project.
• October 31, 2019: Drake Haglan completes 35% design.
• August 7, 2019: Caltrans/FHWA approves Long Approach Roadway Request and Exhibit 6D request for additional costs.
• April 9, 2020: Caltrans approves National Environmental Policy Act document.
• April 16, 2020: County submits Request for Authorization to Proceed with Right of Way Phase to Caltrans.

Failure to approve the Cooperative Agreement would delay implementation of the Byron Highway Bridge Replacement project and jeopardize approximately $17 million in Federal funds that have been programmed for this project.