Stanislaus National Forest Near Cold Springs, California
The scope of work included the installation of new self-cleaning fish screens and a permanent bypass at the entrance to an existing 11-mile long power tunnel, to protect and enhance fish, wildlife, water quality, recreation, and cultural resources. The bypass regulates instream releases for conveying fish, debris, and sediment from the intake to the receiving tailwater pool. The project also included constructing a control building for housing electrical/control equipment necessary to monitor, automate, and maintain the fish screened intake.
The Project posed a number of unique challenges, including: work within the river; installation of a water-filled bladder cofferdam system; dewatering and bypass pumping around the project site; earthwork, grading, and placement of concrete structures downstream of the cofferdam; startup of mechanical pumps and piping; and facility testing and startup. In addition, the isolated location and tortuous dirt access road down to the Project necessitated onsite batching of concrete and processing of excavated material for reuse as backfill.