Cooper Mill Creek Fish Passage & Instream Habitat Improvement Project

The project will remove two barriers and restore fish passage for all life stages of salmonids to 3.0 miles of Cooper Mill Creek and will enhance instream and floodplain habitat. Restoration activities include realignment of the channel and the confluence with Yager Creek which includes the installation of rock weirs, log steps, and a roughened channel (lower reach); a series of nonengineered large wood features and a low alcove feature (middle reach); and, removing the existing concrete sill and adding wood structures upstream and downstream of the sill location (upper reach).

The project will increase the amount and quality of spawning and rearing habitat in lower Cooper Mill Creek, and will restore access to up to 3.0 miles of Coho Salmon, Steelhead Trout, and Chinook Salmon at two partial barriers that have limited the migration for juvenile salmonids under most flow conditions. Additionally, the project will create an alcove feature to provide winter habitat refugia during high flows. Disturbed areas will be replanted with native plant community seeds. Native seeds will also be distributed in bare areas to provide short-term erosion control.