Valley Water provides flood protection to homes, businesses, schools and highways. As part of our commitment, Valley Water will replace the existing aging Palo Alto Flood Basin (PAFB) Tide Gate structure. The structure is 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. Originally built in 1957, it has outlived its 50-year projected life. Additionally, the existing structure is vulnerable to projected future sea-level rise, which reduces the tide gate’s ability to drain the flood basin. The new structure will be sized to account for projected future sea-level rise. The PAFB Tide Gate Structure controls the downstream water levels for Matadero, Adobe and Barron Creeks, which all drain to the PAFB. Upon completion, the new structure will provide significant flood protection benefits to Palo Alto homes, businesses and schools near Matadero, Adobe and Barron creeks, and US Highway 101, and will continue to protect wildlife and habitat in the PAFB.
CEQA Public Review (September 2020)
Valley Water is welcoming public comment on the project's California Environmental Quality Act (CEQA) Mitigated Negative Declaration (MND), which describes the project and its environmental impacts in detail. The document is available for public review and comment from Monday, Sept. 14 to Thursday, Oct. 15.
Please click on the "Reports & Documents" tab above to access the documents.
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
Levee trail surface improvement work is anticipated to start in November 2021 and complete by the end of January 2022. Construction to replace the PAFB Tide Gate Structure is anticipated to start in September 2022. Construction activities will occur between the months of September and January, to avoid impacts to nesting birds. Work will occur from 7 a.m. to 6 p.m. The project is expected to be completed by the end of November 2026.
Due to construction activities, including demolition and replacement of the tide gate structure, a portion of the Adobe Creek Loop Trail will be closed for the majority of the duration of the project. Residents and trail users should comply with trail detour signs and take caution when using the trail.
Expected trail detour during construction.
Reports and Studies
- 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 Flood Basin Emergency Action Plan (2019)
- Palo Alto Food Basin Hydrology, Final Report (July 2016)
Environmental & Community Benefits
- 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.
History and Background
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. The new tide gate structure will be sized to account for projected future sea level rise.
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.