WATERWAY AND LOCATION: The proposed Searsville Watershed Restoration Project (SWRP) is located within the San Francisquito Creek Watershed, in San Mateo and Santa Clara Counties, CA. The project includes multiple components throughout the watershed, including modification of Searsville Dam and Reservoir (37.4072 °N, -122.238 °W), restoring reaches of Corte Madera Creek and San Francisquito Creek upstream and downstream of the dam, expanding Felt Reservoir (37.3949 °N, -122.1856 °W), and upgrading the existing San Francisquito Creek pump station (37.4226 °N, -122.1883 °W). The project would also have potential indirect effects on the entire 12-mile reach of San Francisquito Creek from Searsville Dam downstream to the mouth at San Francisco Bay (Figures 1-3).
EXISTING CONDITIONS: Searsville Reservoir is an artificial impoundment created by the construction of Searsville Dam in 1891 on Corte Madera Creek, just upstream of the confluence where it joins with Bear Creek and forms San Francisquito Creek. Stanford owns and operates the Searsville Reservoir and Dam, the San Francisquito Creek Pump Station, and Felt Reservoir, and uses these facilities to supply non-potable water for irrigation, stock watering, and fire suppression. Searsville Dam presents a complete passage barrier for federally listed steelhead and other native fish in the watershed, and also interrupts natural sediment transport within San Francisquito Creek and Corte Madera Creek. Since construction of the dam, Searsville Reservoir has been filling with sediment, and water storage capacity has been reduced from about 1,200 acre-feet to about 100 acre-feet. The reservoir is expected to eventually fill completely with sediment, at which point sediment originating in the upper watershed would begin passing over the dam and deposit downstream where it could increase flood risk in San Francisquito Creek.
Basic: The basic project purpose comprises the fundamental, essential, or irreducible purpose of the project, and is used by USACE to determine whether the project is water dependent. The basic project purpose is ecological restoration of San Francisquito Creek and water supply reliability.
Overall: The overall project purpose serves as the basis for the Section 404(b)(1) alternatives analysis and is determined by further defining the basic project purpose in a manner that more specifically describes the applicant's goals for the project while allowing a reasonable range of alternatives to be analyzed. The overall project purpose is to restore hydrogeomorphic processes, riparian habitat, and fish passage conditions within the upper San Francisquito Creek watershed; to avoid increasing future flood risk associated with Searsville Reservoir filling with sediment, and to replace Searsville Reservoir’s historic non-potable water storage and supply while improving seismic safety at Felt Reservoir.
PROPOSED WORK: To address these issues, Stanford proposed a multi-phase project in 2022 with the following components that are carried over into the current revised project application (Figures 2-23): (1) construct a gated tunnel through Searsville Dam to allow controlled flushing of trapped sediment, restore natural sediment transport, reestablish fish passage conditions, and improve ecosystem function, while still providing some attenuation of peak storm flows; (2) restore a confluence valley supporting a variety of habitats within the former reservoir footprint above Searsville Dam; (3) construct channel improvements to facilitate fish passage conditions below Searsville Dam, through the proposed tunnel, and in restored creek channels upstream of the dam; (4) construct sediment trapping, habitat improvement, and bank stabilization features on San Francisquito Creek between Searsville Dam and I-280; (5) relocate the existing point of diversion at Searsville Reservoir to the San Francisquito Creek Pump Station site and modify the Pump Station to accommodate increased diversions to Felt Reservoir; and (6) replace Searsville’s lost water storage capacity by constructing a new dam at Felt Reservoir north of the existing dam in order to expand the reservoir’s capacity from approximately 900 acre-feet to approximately 1,800 acre-feet.
San Francisquito Creek flooding in December 2022 and subsequent revisions of hydrologic and hydraulic models for the watershed have led to ongoing reassessment of flood risk factors and potential solutions. After revised modeling of potential project effects, Stanford is proposing two additional project components in their current revised application to address potential flood risk factors:
Initial Coarse Sediment Removal
Most of the coarse sediment (sand and gravel) in Searsville Reservoir is in the southern lobe formed by Corte Madera Creek. To reduce the amount of sand that could potentially deposit in the downstream urban reaches of San Francisquito Creek, Stanford is proposing to mechanically remove much of this material prior to the reservoir flushing described above. To this end, the project would include the excavation and processing of approximately 480,000 cubic yards of sediment from the Corte Madera lobe of the reservoir during the initial construction phase. An estimated 200,000 cubic yards of coarse sediment would be separated and off-hauled. The remaining sediment would be left in the reservoir to be flushed downstream, where gravel would deposit in San Francisquito Creek upstream of I-280 to replenish spawning substrate for steelhead, and silt would flush out to the bay to replenish tidal marsh substrate.
Downstream Detention Basin
Revised modeling indicates that peak flows in San Francisquito creek include higher flows entering from Bear Gulch Creek, which would not be attenuated by the proposed Searsville Dam tunnel. To provide additional peak flow attenuation in addition to that provided by the dam tunnel, Stanford would construct an offstream detention basin at the former site of the Boething tree nursery, on the north side of San Francisquito Creek approximately 1.7 miles downstream of Searsville Dam.
All of these components would require Section 404 of the Clean Water Act authorization. The controlled flushing of accumulated sediment from Searsville Reservoir into the lower tidal reaches of San Francisquito Creek would also require Section 10 of the Rivers and Harbors Act authorization.
AVOIDANCE AND MINIMIZATION: The applicant has provided the following information in support of efforts to avoid and/or minimize impacts to the aquatic environment: Project design goals intended to reduce or avoid impacts include the following:
- Avoid increasing downstream flood risk.
- Design proposed staging areas, creek access routes, instream habitat structures, and sediment removal to reduce/ avoid effects to cultural resources.
- Implement proposed sediment removal/flushing areas to avoid aquatic habitats and neighboring properties upstream of Searsville Reservoir.
- Design reservoir and instream work to minimize impacts to listed species.
The applicant would also implement the following sustainability measures and best management practices:
- Meet final Tier 4 standards for all off-road diesel-powered construction equipment.
- Re-vegetate with low-water-demand, native plants where appropriate and feasible.
- Design with natural processes in mind to minimize ongoing operations and maintenance.
- Erosion and sediment control measures.
- Dust and construction equipment emissions control measures.
- Construction traffic control measures.
- Advance public notification of affected roadways.
- Minimize impacts to bicycle, pedestrian, and equestrian uses.
- Measures to Prevent Spread of Invasive Species and Pathogens.
- Develop and implement construction waste and hazardous materials management plans, spill prevention, containment, and countermeasure plans, and fish rescue and relocation plan.
COMPENSATORY MITIGATION: The project has the primary objective of large scale habitat restoration and would result in overall increase of aquatic resource functions and values.
CULTURAL RESOURCES: The Corps evaluated the undertaking pursuant to Section 106 of the National Historic Preservation Act (NHPA) utilizing its existing program-specific regulations and procedures along with 36 CFR Part 800. The Corps’ program-specific procedures include 33 CFR 325, Appendix C, and revised interim guidance issued in 2005 and 2007, respectively. The District Engineer consulted district files and records and the latest published version of the National Register of Historic Places and has determined that historic properties (i.e., cultural resources listed in or eligible for inclusion in the National Register of Historic Places), are present within the Corps’ permit area; moreover, the undertaking may have an adverse effect on these historic properties. The Corps has engaged in consultation with the SHPO and with Native American tribes to address resolution of any adverse effects.
ENDANGERED SPECIES: The Corps has performed an initial review of the application to determine potential effects on federally threatened, endangered, proposed, or candidate species listed under the Endangered Species Act (ESA), as well as proposed and final designated critical habitat in the vicinity of the proposed project. Based on this initial review, the Corps has made a preliminary determination that the proposed project may affect the following listed species and critical habitat:
- Steelhead (Oncorhynchus mykiss, Central California Coast ESU) and critical habitat are present in San Francisquito Creek downstream of Searsville Dam.
- California red-legged frogs (Rana draytonii) occur in upper San Francisquito Creek watershed upstream of Searsville Reservoir, but have not been documented in the project area in recent decades.
- California tiger salamanders (Ambystoma californiense) occur around Lake Lagunita and other undeveloped Stanford lands northeast of I-280, but are not likely to occur in the project area.
- Bay checkerspot butterflies (Euphydryas editha bayensis) and critical habitat are present on Jasper Ridge east of Searsville Reservoir and south of San Francisquito Creek, but are not likely to occur in the project area.
Pursuant to ESA Section 7, any required consultation with the U.S. Fish and Wildlife Service (USFWS) and National Marine Fisheries Service (NMFS) will be conducted in accordance with 50 CFR part 402. The Corps is the lead Federal agency for ESA consultation for the proposed action. Any required consultation will be completed by the Corps. This notice serves as request to the USFWS and the NMFS for any additional information on whether any listed or proposed to be listed endangered or threatened species or critical habitat may be present in the area which would be affected by the proposed activity.
ESSENTIAL FISH HABITAT: Pursuant to the Magnuson-Stevens Fishery Conservation and Management Act 1996, the Corps reviewed the project area, examined information provided by the applicant, and consulted available species information. The Corps intends to initiate Essential Fish Habitat (EFH) consultation separately from this public notice. A separate EFH consultation package will be sent to the National Marine Fisheries Service (NMFS). The Corps will not make a permit decision until the consultation process is complete. Our final determination relative to project impacts and the need for mitigation measures is subject to review by and coordination with the National Marine Fisheries Service.
NAVIGATION: The proposed structure or activity is not located in the vicinity of a federal navigation channel.
SECTION 408: The applicant may require permission under Section 14 of the Rivers and Harbors Act of 1899 (33 USC 408) if the activity, in whole or in part, would alter, occupy, or use a Corps Civil Works project. There are currently no Corps Civil Works projects within the area, but if any future projects are developed prior to completion of the SWRP then Section 408 review would be required.
WATER QUALITY CERTIFICATION: State water quality certification or a waiver thereof is a prerequisite for the issuance of a Department of the Army Permit to conduct any activity which may result in a fill or pollutant discharge into waters of the United States, pursuant to Section 401 of the Clean Water Act of 1972, as amended (33 U.S.C. § 1341 et seq.). No Department of the Army Permit will be issued until the applicant obtains the required certification or a waiver of certification from the San Francisco Bay Regional Water Quality Control Board.
NOTE: This public notice is being issued based on information furnished by the applicant. This information has not been verified or evaluated to ensure compliance with laws and regulation governing the regulatory program. The geographic extent of aquatic resources within the proposed project area that either are, or are presumed to be, within the Corps jurisdiction has been verified by Corps personnel.
EVALUATION: The decision whether to issue a permit will be based on an evaluation of the probable impact including cumulative impacts of the proposed activity on the public interest. That decision will reflect the national concern for both protection and utilization of important resources. The benefits, which reasonably may be expected to accrue from the proposal, must be balanced against its reasonably foreseeable detriments. All factors which may be relevant to the proposal will be considered including cumulative impacts thereof; among these are conservation, economics, esthetics, general environmental concerns, wetlands, historical properties, fish and wildlife values, flood hazards, floodplain values, land use, navigation, shoreline erosion and accretion, recreation, water supply and conservation, water quality, energy needs, safety, food, and fiber production, mineral needs, considerations of property ownership, and in general, the needs and welfare of the people. Evaluation of the impact of the activity on the public interest will also include application of the guidelines promulgated by the Administrator, EPA, under authority of Section 404(b) of the Clean Water Act or the criteria established under authority of Section 102(a) of the Marine Protection Research and Sanctuaries Act of 1972. A permit will be granted unless its issuance is found to be contrary to the public interest.
COMMENTS: The Corps is soliciting comments from the public; Federal, State, and local agencies and officials; Indian Tribes; and other Interested parties in order to consider and evaluate the impacts of this proposed activity. Any comments received will be considered by the Corps to determine whether to issue, modify, condition, or deny a permit for this proposal. To make this determination, comments are used to assess impacts to endangered species, historic properties, water quality, general environmental effects, and the other public interest factors listed above. Comments are used in the preparation of an Environmental Assessment (EA) and/or an Environmental Impact Statement pursuant to the National Environmental Policy Act (NEPA). Comments are also used to determine the need for a public hearing and to determine the overall public interest of the proposed activity.
The San Francisco District will receive written comments on the proposed work, as outlined above, until March 11, 2026. Comments should be submitted electronically via the Regulatory Request System (RRS) at https://rrs.usace.army.mil/rrs or to Greg Brown at Gregory.G.Brown@usace.army.mil. Alternatively, you may submit comments in writing to the Commander, U.S. Army Corps of Engineers San Francisco District (attention: Greg Brown), 450 Golden Gate Ave., 4th Floor, San Francisco, CA 94102. Please refer to the permit application number in your comments.
Any person may request, in writing, within the comment period specified in this notice, that a public hearing be held to consider the application. Requests for public hearings shall state, with particularity, the reasons for holding a public hearing. Requests for a public hearing will be granted, unless the District Engineer determines that the issues raised are insubstantial or there is otherwise no valid interest to be served by a hearing.