Palo Alto Horizontal Levee Completion Celebrated

City and Regional Partners Recognize Completion of Nature-Based Palo Alto Horizontal Levee

First Bay Area Nature-Based Solution Protecting Against Sea-Level Rise and Improving Marsh Habitat

PALO ALTO, CALIF. --- The City of Palo Alto, San Francisco Estuary Partnership, and regional and state partners announced today the completion of the Palo Alto Horizonal Levee Pilot project, a first in the Bay Area to use a nature-based solution protecting against sea level rise and improving marsh habitat in the San Francisco Bay.

Located on a 500-foot-long section of the coastline on Harbor Marsh in the Palo Alto Baylands, the Palo Alto Horizontal Levee Pilot Project is the first of its kind on the San Francisco Bay shoreline to use effluent from the Palo Alto Regional Water Quality Control Plant to irrigate native plantings. Construction of the $4.6 million permanent project began on September 8, 2025, and is now complete.

"By working together to find new ways to protect against sea level rise, we can do great things. The Palo Alto Horizontal Levee permanent pilot project was developed through bold innovation, thoughtful leadership, and regional partnerships," said Vicki Veenker, Palo Alto mayor. "Our hope is that Palo Alto's design of this first nature-based living levee, spurs similar projects in the future all around the Bay Area."

The City of Palo Alto and Estuary Partnership/Association of Bay Area Governments are partnering with scientific researchers at United States Geological Survey (USGS), California State University Channel Islands, and University of California Davis to study the levee and understand how it changes over time, and what habitat benefits it may offer compared to a traditional levee. The project involves community education about nature-based solutions and engaging community scientists through partnerships with Nuestra Casa, Association of Ramaytush Ohlone, Save the Bay, and Environmental Volunteers.

"We are excited to celebrate the construction of the Palo Alto Horizontal Levee project which has allowed us to look at new ways to address sea level rise and water quality improvement in the same project," said Heidi Nutters, assistant director for the San Franciso Estuary Partnership. "As the project has moved forward, we have also been able to collaborate with our many partners to find ways to increase public access, restore habitat creating better spaces for local wildlife, and expand our academic understanding of climate adaptation solutions while strengthening resilience for the Palo Alto community."

This innovative project will inform how future large-scale "living levee" projects of this kind might be used to help the Bay Area adapt to sea level rise. Horizontal levees, sometimes called "living levees", are gradual slopes built with earth. Landscaped with native plants, they create and support healthier coastal ecosystems. Traditional levees and seawalls are usually steep slopes and built with earth, rocks, steel, or concrete. They offer little or no habitat.

"Communities around the Bay are facing the same fundamental question: What are we going to do about sea level rise?" said Susan Adams, President of the Association of Bay Area Governments (ABAG) and Rohnert Park City Councilmember. "ABAG's purpose is to help the nine-county Bay Area's cities address regional challenges in housing, transportation, and the environment. I'm grateful the City of Palo Alto worked with ABAG to help answer that question through the innovative Horizontal Levee Project."

This project received grant funding from the California Department of Water Resources, the Environmental Protection Agency, the City of Palo Alto, and the California State Coastal Conservancy, reinforcing the regional significance of the Palo Alto Horizontal Levee Pilot project and possible influence of additional projects within the Bay Area.

"The Coastal Conservancy awarded grant funds for this project because of the important role it plays in furthering our understanding of how built infrastructure, like flood protection levees, can be put to work for the benefit of the Bay and all of us that live here," said Evyan Borgnis Sloane, deputy executive officer for the California State Coastal Conservancy. "As we prepare for a future with increased sea level rise and flooding, this is exactly the type of bold, innovative nature-based solution we need to protect our communities and infrastructure while preserving and even improving the health of the Bay."

The celebration included a community trail walk to officially recognize the opening of the relocated and widened trail connecting hikers and bikers to the Baylands Nature Preserve and Byxbee Park trails and San Francisco Bay Trail system.

The Regional Water Quality Control Plant is the sixth largest treatment plant in the Bay Area treating 20 million gallons of sewage a day - 24 hours per day, seven days a week. In operation since 1934, the Regional Water Quality Control Plant is owned and operated by the City of Palo Alto. As a regional partner, it treats wastewater for East Palo Alto Sanitary District, Los Altos, Los Altos Hills, Mountain View, Palo Alto, and Stanford University. Major projects and upgrades to the Regional Water Quality Control Plant are underway totaling approximately $397 million increasing efficiency and reliability and one of the first water quality control plants to proactively comply with new regulations for protecting the San Francisco Bay. The completed living levee nature-based solution design has a wide gentle slope which helps a marsh adapt as sea level rises and uses treated wastewater to restore native habitat on its slope.

For more about this project, visit www.paloalto.gov/HorizontalLevee

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Photo Reference Names from Left to Right: Evyan Sloane, Deputy Executive Director, State Coastal Conservancy; Pat Showalter, PE, Mountain View City Council Member; Cheree Peterson, Deputy Regional Administrator, Environmental Protection Agency; Gregg Castro, Cultural Director, Association of Ramaytush Ohlone; Matt Maloney, Deputy Executive Director for Metro Planning & Policy, ABAG/Metropolitan Transportation Commission (MTC) ; Ed Lauing, Palo Alto City Council Member; Heidi Nutters, Assistant Director, San Francisco Estuary Partnership; Vicki Veenker, Palo Alto Mayor; Brad Eggleston, Director of Public Works, City of Palo Alto; Susan Adams, President, ABAG Executive Board

Sent By:

Meghan Horrigan-Taylor

Chief Communications Officer

City Manager's Office

Office Phone: (650) 329-2607

Email: [email protected]