Searsville Dam was built in 1892 and is located on San Francisquito Creek. The watershed supports a run of steelhead in several upstream tributaries and may have historically supported coho salmon as well. The dam does not provide potable water or hydropower. Its primary use is to provide irrigation water to the Stanford University campus and some flood control benefits to the downstream cities of Palo Alto, Menlo Park, and East Palo Alto.
Corte Madera Creek, San Francisquito Creek watershed in Portola Valley, CA
Height: 65 ft., Length: 275 ft. Total designed capacity: 1,840 acre ft., forming Searsville Reservoir, 90% filled with sediment
Beyond Searsville Dam Coalition, Friends of the River, American Rivers, California Department of Fish & Wildlife, CalTrout, National Marine Fisheries Service, Stanford University, San Francisquito Creek Joint Powers Authority, Grassroots Ecology, local landowners, downstream neighbors, and others.
Searsville Dam has lost over 90% of its original water storage capacity as roughly 1.5 million cubic yards of sediment have filled in the reservoir. Without intervention, sediment will completely fill the reservoir and bury any flood control benefits. The dam poses an impassable barrier to federally threatened steelhead attempting to migrate to historical spawning grounds mostly upstream of the current dam site in the San Francisquito Creek watershed. Although a few steelhead have been seen spawning below the dam in past years, they can no longer access the perennial high-quality habitat above the dam. The offspring of resident fish upstream of the dam also cannot swim downstream to San Francisco Bay and the Pacific Ocean. In addition to preventing fish passage, the dam also inhibits ecological function and reduces water quality. The dam blocks large woody debris, important for creating habitat to power the watershed’s food web, from washing downstream. It also blocks sediment that, if able to move downstream, could slow sea level rise to maintain the resilience of tidal marshes along the eroding San Francisco Bay shoreline. The sediment trapped behind the dam and costs associated with ongoing management of the dam for flood risk present the biggest obstacles to dam removal. While simply removing the dam and letting all the sediment move downstream would compromise existing flood control features in a heavily urbanized and modified watershed, leaving the dam in place will also increase flood risk and continue impairing the watershed. It is crucial to determine a carefully-studied solution that both reduces the risk of catastrophic flooding for communities downstream of Stanford’s campus and allows the creek to flow freely again.
Removing Searsville Dam after the strategic flushing of sediment is an important opportunity to significantly increase spawning and rearing habitat for federally threatened Central California Coast steelhead. San Francisquito Creek is an anchor watershed that is necessary for recovery of the species. Partners and community members have been working to identify feasible opportunities to allow fish passage at Searsville Dam for over a decade. Years of Searsville Advisory Group meetings with interested parties and partners have taken place and a key consultant report recommending punching a hole in the base of the dam was released in 2015. In February 2023, Stanford University described the “Searsville Watershed Restoration Project” in a formal Notice of Preparation to work with the California Department of Water Resources and US Army Corps of Engineers to develop a joint draft environmental impact report for the project in fall 2023. Complicating the situation is the significantly altered watershed downstream of Searsville Dam, where the existing channel of San Francisquito Creek can no longer safely pass flows without flooding neighboring cities. Significant investments in replacing undersized culverts and other barriers at road crossings have been made, but more infrastructural improvements are needed miles downstream to allow sediment and stream flows to move out to San Francisco Bay without backing up floodwaters onto densely populated urban areas. Still, no timeline for completion of the remaining undersized culverts and road crossing infrastructure has been provided by the San Francisquito Creek Joint Powers Authority. It remains unclear how the proposed “Searsville Watershed Restoration Project” will be permitted without these related infrastructure projects in place. In 2023, Stanford University identified four priority objectives for addressing the challenges associated with this dam. First, the university recognizes it must finally enable fish passage above the dam to meet requirements under the federal Endangered Species Act and to join the ranks of the other Bay Area water districts that own and operate dams to restore access to historical habitat. Second, sediment piled behind the dam needs to move downstream in some fashion. Third, flood risk for downstream communities along San Francisquito Creek and the Bay must not increase as a result of the project. Fourth, the university wants to use the pending solution for the dam to support environmental research at the Jasper Ridge Biological Reserve on which Searsville Dam and reservoir are located.
Searsville Dam and Reservoir have been a contentious subject for Stanford University and those paying attention to steelhead and salmon issues in the Bay Area for decades. The challenge of balancing flood risk and fish passage, the very low abundance of steelhead on the Peninsula, and the extremely high cost of any potential solution makes finding a path forward difficult. However, the environmental review process for the future of Searsville Dam is now moving in earnest. In late 2023, Stanford University is expected to release an Environmental Impact Report on their preferred alternative for Searsville Dam. Despite years of inaction, movement towards addressing the sediment – and eventual removal of the dam – is beginning in a formal process that will incorporate multiple opportunities for public comment. CalTrout remains committed to finding a solution for Searsville Dam that includes full dam removal to create long-term sustainability and ecological function for the benefit of the San Francisquito Creek watershed, fish, and people.
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