(Sept. 7, 2012)
Today, the district completed the fixes to stop the seepage under the Palo Alto Tide Gate structure. The contractor completed the plugging operation at about 12:15 p.m., staying onsite to observe arrival of the high tides and confirm proper functioning of the gates.
District staff will return on Monday for additional inspection of the gates to ensure they are continuing to function properly.
The tide gates are a critical element for both wildlife habitat and flood protection for Palo Alto.
Keeping water levels within the flood basin within a specified elevation allows the islands in the center to serve as habitat for marsh wildlife such as the Salt Marsh Harvest Mouse and the California Clapper Rail which are protected species. The gates prevent extreme high tides from inundating the habitat areas with salt water and also accumulate freshwater runoff from the Matadero, Adobe and Barron creeks until they can be released to the bay at the next low tide.
The tide gates also protect Palo Alto from a flooding situation should a heavy rain event and a high tide occur at the same time. The flood basin has the capacity to retain several hours of heavy storm runoff to allow the next low tide to occur and release stored flood waters to the bay.
The tide gates at the Palo Alto Flood Basin were built in the late 1950s. If the seepage persists, it could threaten the foundation of the concrete tide structure. The constant scouring of the tides has washed away sand and sediment from between the rocks under the concrete structure.
For more information, contact Ed Morales at (408) 630-2880.