Valley Water provides flood protection to homes, businesses, schools and highways. As part of our commitment, Valley Water will design and construct a seismic retrofit and rehabilitation of the existing Palo Alto Flood Basin (PAFB) Tide Gate structure to extend its service life. Phase 2 of this project includes working with the United States Army Corps of Engineers to establish a long-term replacement tide gate structure, under the South San Francisco Bay Shoreline Phase II Project. That structure will be located where the PAFB connects to the San Francisco Bay, half a mile northeast of the Byxbee Park parking lot on the Adobe Creek Loop Trail.
Palo Alto Flood Basin Tide Gate Structure Seismic Retrofit and Rehabilitation Project
The project scope has been revised to include two phases. Phase 1 work will be to design and construct a seismic retrofit and rehabilitation of the existing tide gate structure to extend the service life. Phase 2 work will be to work with the United States Army Corps of Engineers for a long-term replacement tide gate structure as part of the South San Francisco Bay Shoreline Phase II Project.
Valley Water informational project presentations to the City of Palo Alto Parks and Recreation Commission
- August 24, 2021, meeting details: https://www.cityofpaloalto.org/Departments/Community-Services/Other-Services/Commissions/Parks-and-Recreation-Commission, and
- June 22, 2021, meeting details: https://www.cityofpaloalto.org/Departments/Community-Services/Other-Services/Commissions/Parks-and-Recreation-Commission.
Final CEQA Mitigated Negative Declaration (MND) (March 2021)
The final Mitigated Negative Declaration (MND) CEQA document is now available and can be found under the "Reports and Documents" tab above.
Staff Presentation at the Sept. 9 Palo Alto Sea Level Rise Public Meeting
Valley Water staff attended the City of Palo Alto's Sea Level Rise Virtual Meeting on Sept. 9, 2020, and presented on the PAFB Tide Gate Structure Replacement Project and the South San Francisco Bay Shoreline Project. A recording of the meeting can be viewed at this link.
Virtual Project Update Meeting - Summer 2020
Valley Water hosted a public meeting for the Palo Alto Flood Basin Tide Gate Structure Replacement project on Wednesday, June 24 at 5:30 P.M. The meeting included a presentation on the background of the project and information about the project team’s current design concepts.
What to expect
Onsite construction for Phase 1 work for the seismic retrofit and rehabilitation of the existing tide gate structure is anticipated to start in September 2024 and conclude by January 2025, to avoid impacts on nesting birds.
Due to the construction activities, a portion of the Adobe Creek Loop Trail will be temporarily closed for the duration of construction.
Reports and Studies
- CEQA Final Mitigated Negative Declaration (March 2021)
- CEQA Final Mitigated Negative Declaration Appendices (March 2021)
- CEQA Mitigated Negative Declaration - Notice of Intent (September 2020)
- CEQA Draft Mitigated Negative Declaration (September 2020)
- CEQA Draft Mitigated Negative Declaration Appendices (September 2020)
- Project Planning Study Report (August 2020)
- Palo Alto Food Basin Hydrology, Final Report (July 2016)
Board and Committee Meeting Agendas
- The PAFB Tide Gate Structure prevents flooding by keeping high tide waters out of the PAFB and controlling the downstream water levels of Matadero, Adobe and Barron Creeks, which all drain to the PAFB.
- The PAFB tide gate structure is an important component of providing flood protection for residents along the lowers reaches of Adobe, Barron, and Matadero Creeks and Highway 101.
- The PAFB Tide Gate Structure also protects habitat, including for sensitive wildlife, by preventing tidal inundation in the PAFB.
The PAFB Tide Gate Structure is located where the PAFB connects to the San Francisco Bay. The structure is located half a mile northeast of the Byxbee Park parking lot on the Adobe Creek Loop Trail. The structure was originally built in 1957, and has outlived its 50-year projected life. The structure controls the downstream water levels for Matadero, Adobe and Barron Creeks, which all drain to the PAFB. The tide gate structure helps keep high tide waters out from the PAFB and allows it to empty out twice a day during low tides. The tide gate structure helps prevent flooding in the lower reaches of these creeks and inundation of wildlife habitats in the basin. The existing structure is vulnerable to projected future sea level rise, which reduces the tide gate’s ability to drain the flood basin.
Due to its age and location in a corrosive marine environment, the tide gate structure shows signs of deterioration, including spalled concrete, exposed reinforcement steel, and water seepage through cracked concrete and leaky tide gate seals. Seepage was previously addressed by an emergency repair project in 2012. In 2017 Valley Water attempted minor maintenance repairs that would have extended the life of the structure. Construction was suspended when dewatering the work area revealed additional evidence of damage from aging. Valley Water has determined that replacement of the structure, rather than repair, is warranted to ensure flood protection for residents along the lower reaches of Adobe, Barron and Matadero Creeks and Highway 101.