Hayer Dam

Project History

Hayer Dam was originally built mainly for agricultural purposes, and was a seasonal impediment to fish passage on Dry Creek. The dam checked up water during the summer to provide for adjacent gravity diversion and storage structures. The dam renovation completed by SAFCA removed the potential obstructive structure and maintained the water diversion. The project area contains critical habitat for the Central Valley Steelhead ESU (evolutionarily significant unit) and the project impacts to critical habitat were evaluated by National Oceanic and Atmospheric Administration (NOAA) Fisheries .
Dewatering and excavation began in September 2004 during a period when neither adult upstream spawning migration or juvenile out-migration was occurring. The coffer dams were installed one at a time to allow any fish in the dewatering area to move out of the area. After installation of both dams but before structural renovation began, any and all fish species remaining in the dewatered area were manually removed and released upstream. Overall, the project has long term benefits as it allows fish to easily move up or down stream.