Stanford's Dam Problem

“Sooner or later Searsville Dam must come down, and the whole San Francisquito Creek watershed can be treated as the ecological treasure that it is.”
— Pete McCloskey, former U.S. Congressman and co-author of the Endangered Species Act; Stanford Law alumnus

Photo by Joel Avila, Hawkeye Aerial Photography

Stanford University owns and operates the 110 year old Searsville Dam. The 65-foot-tall dam creates Searsville Lake. Once used by the university for recreation, the lake is now at less than 10% of its original volume because of siltation, and currently serves little more than the university’s golf course. To irrigate its golf course, Stanford diverts over 100 million gallons of water from the watershed each year. Water in the lake gets very warm, causing algae blooms that deplete the water of oxygen. The “lake” has become filled with invasive species of fish and bullfrogs that migrate downstream in high flows and prey upon juvenile fish and native frogs. But, despite being denied access to its healthy spawning grounds, robbed of its much needed cold-water flows, and preyed upon by invasive species, the steelhead trout population below the dam hangs on by a thread.

Steelhead Trout

Steelhead trout (Image, US Fish & Wildlife Service)

Central California Coast (CCC) steelhead trout once thrived in the creeks of the Santa Cruz Mountains. They were culturally significant and a staple of the diet of the native Ohlone. Steelheads are basically rainbow trout that migrate from their natal streams to the ocean. There, they live for up to eight years, and get as large as 40 pounds, before returning to their home stream to spawn. Steelheads have almost completely disappeared from Central California’s coastal creeks. They are listed as threatened on the federal Endangered Species Act (ESA). One of the Bay Area’s last remaining steelhead trout populations is in the San Francisquito Creek watershed, which flows through Stanford University. The watershed starts at the ridgeline of the Santa Cruz Mountains, near La Honda, and empties into the South Bay wetlands in East Palo Alto.

In its current state, San Francisquito Creek, a major tributary to San Francisco Bay, provides habitat for Central California Coast (CCC) steelhead, though far from ideal. Steelhead’s freshwater habitat needs include:

Cool water temperatures, for successful embryo incubation and the health and survival of juvenile and adult fish.
High dissolved oxygen content in the waters the fish inhabit.
Suitable gravel substrate, for spawning.
Large woody debris, anchored in the fish’s river habitat, to create cool deep water pools with reduced flow that provide spawning habitat and refuge from predators.
Sustained and sufficient flow, to allow unimpeded migratory passage of adult and juvenile fish.
Consistent inundation of the areas that are used for spawning, to ensure that placed fish egg clusters, or “redds,” remain inundated until eggs hatch.

The San Francisquito Creek areas inhabited by the steelhead are now so degraded they cannot reliably provide these habitat attributes.

Searsville Dam

Photo by Joel Avila, Hawkeye Aerial Photography

The primary cause of degraded habitat in San Francisquito Creek is the presence of Searsville Dam and Stanford's excessive diversion of water from the watershed above the dam. The water diversions have reduced flows in San Francisquito Creek dramatically. San Francisquito Creek has also seen substantial declines in the riparian vegetation along the creek's banks that used to provide much more shade, protection from solar radiation — in part, due to loss of the natural flow conditions needed to support such vegetation. This loss of flow and loss of riparian vegetation has seriously degraded the water quality and habitat value of the creek. With decreased flow, the creek is shallower, making it more prone to being heated by solar radiation. What's more, the loss of protection from solar radiation has exacerbated the heating of the creek. Warmer water temperatures in the creek reduce dissolved oxygen levels, as cold water inherently has a greater capacity for retaining dissolved oxygen.

Searsville Dam further harms CCC steelhead by blocking the fish’s access to the upper San Francisquito Creek watershed that formerly provided important habitat for the fish. The watershed includes the major tributaries Corte Madera Creek, Los Trancos Creek, Sausal Creek, and Bear Creek. The riparian areas of these creeks are in very good shape, primarily because much of the area is preserved as state and local parks, or is held as private ranches, and is not subject to intense logging practices or suffering from industrial pollution. These creeks provide quality spawning and rearing habitat for steelhead trout. They run cold and clear out of the Santa Cruz Mountains, providing up to 20 miles of steelhead spawning habitat. Unfortunately, there are no fish ladders or other bypass devices at Searsville Dam that allow the fish to swim past the dam. It is a completely impassable barrier for the fish.

Photo by Matt Stoecker, Stoecker Ecological

Stanford’s Maintenance of Dam Violates the ESA

Stanford’s operation and maintenance of Searsville Dam, Searsville Reservoir, and its water diversions are causing harm to CCC steelhead and increasing the “taking” of CCC steelhead. A “take” of a listed species, within the meaning of the federal Endangered Species Act (ESA), occurs by killing or injuring an individual member of the species, or by engaging in an act that causes significant habitat modification or degradation that kills, injures, or adversely affects the species by significantly impairing essential behavioral patterns, including breeding, spawning, rearing, migrating, feeding, or sheltering.

For Stanford’s operation and maintenance of Searsville Dam and Searsville Reservoir to be legal under the ESA, Stanford must consult with the National Marine Fisheries Service (NMFS, aka NOAA Fisheries) and obtain an Incidental Take Permit under ESA Section 10. Stanford has not obtained such a permit. As such, Stanford is in violation of the Endangered Species Act, Section 9.

The Ecological Rights Foundation (EcoRights) and co-plaintiff, Our Children’s Earth Foundation brought an ESA citizen suit against Stanford for the university’s ESA section 9 violations. EcoRights seeks an injunction requiring Stanford to:

Apply for an ESA section 10 Incidental Take Permit.
Curb its diversion of water from San Francisquito Creek.
Complete feasibility studies for securing CCC steelhead access to the upper watershed above Searsville Dam.
Implement the needed remedial measures that will secure CCC steelhead access to the upper watershed.