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Palo Alto Flood Basin Tide Gate Structure Replacement Project

About This Project

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 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.

Project Factsheet (June 2020)

Palo Alto Flood Basin Tide Gate Structure
Datapoints
Status
On Target
Phase
Design
Location
Palo Alto
Schedule
Const. Award Summer 2022/Const. Start Sept. 2023
Funding
Watershed & Stream Stewardship Fund
News and UpdatesNews and Updates
Reports and DocumentsReports and Documents
Environmental and Community BenefitsEnvironmental and Community Benefits
History and BackgroundHistory and Background
News & Updates

Palo Alto Flood Basin Tide Gate Structure Replacement Project Soil Sampling Work

Soil sampling work will be conducted in the vicinity of the existing Palo Alto Flood Basin Tide Gate Structure from Feb. 16 to Feb. 28, 2022. This sampling work is for the Palo Alto Flood Basin Tide Gate Structure Replacement Project which is planned to start on site construction on Sept. 1, 2023. The soil samples will be tested to determine soil reuse eligibility of planned excavation work for the main project.
 

Valley Water informational project presentations to the City of Palo Alto 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 to replace the PAFB Tide Gate Structure is anticipated to start in September 2023. 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.

    For more information:

    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.
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    Palo Alto Flood Basin Tide Gate Structure
    History & 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. 

    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.  

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    Emergency repair work on the Palo Alto Flood Basin Tide Gate in 2012