Located on the shore of Harbor Marsh in the Palo Alto Baylands, the city of Palo Alto is in the construction process of the region’s first horizontal levee, a pilot project designed to balance flood protection and improvements in habitat and water quality.

 Unlike traditional steep levees, this horizontal levee will be built as a wide, vegetated ecotone slope that absorbs wave energy, providing wildlife habitat and supporting natural adaptation to sea-level rise. The Palo Alto Levee Project aims to test whether this more eco-friendly approach can replace or enhance older flood-control infrastructure around the Bay. 

According to the city website, the water stored by the levee will replicate historic freshwater seepage that once supported a variety of biomes, as the water moves through soil and plant roots before reaching the bay, also providing additional improvements to the environment by removing nitrogen and reducing contaminants of concern. 

The City of Palo Alto and its partner, the San Francisco Estuary Partnership, are collaborating with local universities, federal agencies and non-profit organizations to evaluate the success of the Horizontal Levee. Researchers are conducting vegetation surveys to study the restoration of native species, tracking how soil builds up on the levee slope to understand how it may respond to sea-level rise.  

During construction, parts of the Baylands near Harbor Marsh are fenced off, limiting visitor access and altering hiking routes. 

Edison Lee, a junior at Palo Alto High School, said he personally doesn’t find the construction too inconvenient, but does impact the way he enjoys the baylands when he visits weekly. 

“The construction being done impedes the natural feel of the baylands during my Saturday morning runs,” Lee said. 

The city emphasizes that one of the project’s goals is to maintain opportunities for recreation while upgrading resilience to sea-level rise.