Searsville Dam FAQ
Last updated: May 5, 2015
What are the Searsville Dam and Reservoir, and how does Stanford use them?
Searsville Dam and Reservoir are located in Stanford's Jasper Ridge Biological Preserve in the San Francisquito Creek watershed, adjacent to Portola Valley and Woodside, west of Interstate 280. The dam was built in 1892 by the for-profit Spring Valley Water Company and acquired by the university in 1919. The reservoir created by the dam was once a popular recreational area. The Stanford Board of Trustees formally designated Jasper Ridge as a biological preserve in 1973 and, in 1975, ended recreational use of Searsville Reservoir.
Today, sedimentation has reduced the reservoir to less than 10 percent of its original water capacity. Water stored at Searsville provides one of several sources of non-potable water used at Stanford for landscape irrigation, agriculture and fire protection. Due to the ongoing drought, no water has been taken from Searsville since 2013.
Searsville Reservoir is a major feature of the 1,189-acre Jasper Ridge Biological Preserve, playing a key role in the preserve's research and education mission. It provides opportunities for researchers and students to study a range of globally and locally important habitats, environmental issues and engineering topics.
Why doesn't Stanford remove Searsville Dam?
Removing Searsville Dam was one of the many options studied by the Searsville Steering Committee during its four-year review. Committee members came to the conclusion that the dam may serve a useful purpose as a "check dam" during severe storms, detaining and delaying high creek flows from reaching the downstream stretches of the creek.
In order to remove the dam, much of the accumulated fine sediment would need to be removed, potentially by releasing downstream some part of the 2.7 million cubic yards of trapped sediment. If this can be accomplished, it would not preclude a subsequent step to remove the dam – that is, if it can be determined that the risk of downstream flooding would not increase.
Why can't Stanford simply dredge the reservoir and remove the sediment?
Studies of the sediment suggest that it would take nine to 10 years to mechanically dredge, dry and haul it away to disposal sites, requiring as many as 150,000 truck trips to and from Jasper Ridge Biological Preserve. The steering committee felt that this type of dredging and removal would be untenable for the community residents in the area, as well as the ecosystem at Jasper Ridge Biological Preserve, the species that thrive there and the entire San Francisquito watershed.
Is Stanford diverting water from Searsville Lake and San Francisquito Creek to irrigate its golf course?
No, Stanford has not diverted water from Searsville since March 2013. Where we do take water from San Francisquito Creek, Stanford's permits have a minimum bypass flow of water for the passage of fish before any water can be diverted.
Irrigation on campus, which has been reduced because of the drought, comes from water stored in Felt Lake in the Stanford foothills and from Stanford's wells.
The steering committee recommends that diversion functions formerly at Searsville be relocated downstream with expanded storage upstream at Felt Lake Reservoir as a replacement for water provided from Searsville.
Did Stanford study any other dam removal efforts as part of its review process?
Yes. Stanford worked with the expert environmental engineering firm URS, which provided information on a number of dam removal and watershed restoration projects, including the San Clemente Dam project on the Carmel River.
How will the two options under consideration affect steelhead?
The Central California Coastal steelhead, which are a threatened species, are the anadromous form of rainbow trout, meaning they hatch and spend the early part of their lives in freshwater creeks such as San Francisquito, live most of their lives at sea and return to their freshwater creek of origin to spawn. Both options being proposed will result in improved fish passage and access to creek habitat.
Is Searsville Dam safe?
Yes. Searsville Dam is regularly inspected by the state's Division of Safety of Dams. That agency confirmed the dam's safety as recently as Dec. 28, 2012, in a letter that says: "The dam is considered safe for continued use and no additional engineering or geologic analyses involving the dam, abutments, or foundation are judged necessary at this time." The 68-foot-high concrete gravity dam, comprised of large concrete blocks and a stout cross section, according to the state, "is considered stable for the static, seismic and flood loading conditions and has an outlet capacity capable of meeting our requirements."
If there are two options on the table, who will make the final decision about the future of Searsville Dam, and when?
As it works through the details of the two options, Stanford anticipates working closely with the many federal, state and regional agencies whose approval will be needed before any action is taken at Searsville Dam and Reservoir. Those agencies include the U.S. Fish and Wildlife Service, National Marine Fisheries Service, U.S. Army Corps of Engineers, California Department of Fish and Wildlife, State Water Resources Control Board and San Francisquito Creek Joint Powers Authority. Some of the careful reviews required by these agencies may take years. Key will be a resolution for the sediment trapped behind the dam.
In the process of seeking a final decision, Stanford will seek ways to cover the financial implications of changes at Searsville Dam and Reservoir. Initial cost estimates are as high as $100 million.
Who were the members of the Searsville Steering Committee?
The committee was co-chaired by Jean McCown, Stanford director of community relations, and Chris Field, professor of interdisciplinary environmental sciences, Earth system science and biology, faculty director of Jasper Ridge Biological Preserve and director of the Carnegie Institution's Department of Global Ecology. The committee includes prominent faculty: Jeffrey Koseff, co-director of the Woods Institute for the Environment; Pamela Matson, dean of the School of Earth, Energy & Environmental Sciences; Buzz Thompson Jr., professor of natural resources law and co-director of the Stanford Woods Institute for the Environment; David Freyberg, associate professor of civil engineering and hydrology; and Richard White, professor of history. Staff members include senior leadership and specialists in conservation, land use, environmental sustainability and water conservation.
What type of community input did Stanford receive as it conducted its study of Searsville Dam?
Throughout the study process, Stanford worked with an advisory group of external representatives from environmental organizations, regulatory agencies and county, neighborhood groups and municipal governments to provide input to the steering committee's evaluation process. The report of that committee and the comments of individual members were included in the Searsville Steering Committee report.
More information on Stanford and the Searsville Dam: http://news.stanford.edu/searsville/