I-680 Alameda Creek Bridge Scour Repair Project (EA 04-0P910)

The I-680 Alameda Creek Bridge Scour Repair Project, managed by the California Department of Transportation (Caltrans) District 4, focuses on critical infrastructure repairs at Bridge 33 0047 in Alameda County. The primary objective is to mitigate scour damage on the leading edges of Piers 8 and 9, which was caused by restricted flows from a nearby mining operation. This work involves excavating a scour hole approximately 40 feet wide and up to five feet deep and placing shot rock slope protection around the upstream edges of Piers 7, 8, and 9 to ensure bridge stability. Additionally, the project includes bridge deck rehabilitation, which consists of cold planning and removing 1.5 inches of polymer concrete, replacing expansion joint seals, and installing three-quarter inches of polyester concrete using slip forming paving machines. All removed asphalt and concrete will be disposed of at approved off-site facilities. The project is governed by several regulatory frameworks, including Lake and Streambed Alteration Agreement EPIMS-ALA-54540-R3 under Fish and Game Code section 1602 and California Endangered Species Act Incidental Take Permit 2081-2024-072-03. These permits address environmental impacts, specifically the incidental take of the California tiger salamander. The California Department of Fish and Wildlife has issued Notices of Determination confirming that the project will not have a significant environmental effect within its jurisdiction, provided that the adopted mitigation measures and monitoring plans are followed. The project is located on Interstate 680 at PM R10.15 in an unincorporated area of Sunol, and the lead agency contact is Julian Smith of Caltrans.