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Fish Getting Much Needed Help in the Alameda Creek Watershed

Protecting the quality of San Francisco’s drinking water starts with protecting the ecosystem and native wildlife around the SFPUC’s reservoirs and watersheds. To address that issue, the SFPUC built a state-of-the-art fish ladder in in the Alameda Creek Watershed, that will help monitor and protect the threatened species of steelhead trout.

“We’ve been working on rainbow trout and steelhead restoration in the Alameda Creek Watershed for about 20 years now,” said Brian Sak, SFPUC Supervising Biologist. “We have finally gotten to the point where we’re starting to release water from Calaveras Dam to improve both spawning habitat and rearing habitat conditions for the fish.”

Fish Passage Facilities within the Alameda Creek Watershed.

The native species of the steelhead trout was abundant in the Alameda Creek Watershed, until they were federally listed as a threatened species back in 1997. The SFPUC’s Natural Resources and Lands Management Division identified this native fish population as the perfect candidate for restoration efforts.

“We now have a fish ladder which will allow adult fish to navigate and get above the divergent dam, which they have not been able to do historically and will also help juvenile fish out-migrate downstream,” said Tim Ramirez, SFPUC Natural Resources and Lands Management Division Manager. “The fish ladder provides a window of time for the fish to navigate upstream above the dam and downstream during winter storm events.”

Alameda Creek Diversion Dam, The project will entail partial demolition of the existing Alameda Creek Diversion Tunnel’s intake structure, and construction of a fish ladder to facilitate fish passage around the existing Alameda Creek Diversion Dam, a new diversion structure comprised of four tee-shaped fish screens, an intake manifold and wet well, and three adjoining, concrete-box culverts in the bed of Alameda Creek.

The fish ladder is essentially water flowing under steel grates that flow down from the top of a diversion dam that was originally built in the 1930s. The fish ladder is intended to mimic a naturally flowing river, with narrow areas of rapid waters and swirling pools that allow the fish to rest. This greatly benefits the endangered steelhead trout population and gives the fish more water to grow up in and spawn in.

“We want the next generation to be able to come here and experience these places and to see these things,” said Ramirez. “And I think our folks are a big part of that future.”