The County proposes to replace the existing Jose Basin Road Bridge (Bridge No. 42C0264) over Bald Mill Creek, located approximately 2.3 miles northeast of Auberry Road between the communities of Auberry and Lerona. The Project would replace the existing single-lane bridge with a new two-lane bridge that meets current standards. According to the most recent Caltrans bridge inspection report (May 2020), the existing structure has a sufficiency rating of 59.3; however, the bridge was previously flagged as functionally obsolete due to the narrow single-lane bridge width. Since the existing bridge is supported on reinforced concrete and steel bents, widening of the bridge would not be economically feasible; therefore, a bridge replacement is necessary. The existing bridge was constructed as a simply supported 2-span structure in 1947. In 1948, steel-column bents were added at the mid-point of each span. In 2001, the steelcolumn bents were widened by placing an additional column on each side. The existing bridge is 126 feet long and 16.7 feet wide. The superstructure consists of Bailey bridge truss units with a cast-in-place reinforced concrete deck. The substructure consists of reinforced concrete seat abutments with steel-column and concrete column bents. Supports are founded on reinforced concrete spread footings on bedrock. Changes to the vertical alignment are not anticipated; however, the replacement bridge will be realigned and constructed downstream of the existing bridge. The realignment is necessary to allow the existing bridge to function as an on-site detour during construction; otherwise, the detour route for the Project is 25 miles. Retaining walls be constructed on the downstream side north and south of the bridge to support the realigned approaches. Tree and vegetation removal is anticipated. The existing right-of-way on Jose Basin Road is 60 feet wide centered about the centerline. Permanent right-of-way acquisition and temporary construction easements are anticipated. Utility relocation is not anticipated for the Project; however, further investigation is required. The Project area is located within Zone RC-40 Resource Conservation.
