Across the Bay Area, a new kind of levee is rising, one that mimics natural estuaries by using gradual slopes and native plants. Unlike traditional barriers, these horizontal levees promise both flood protection and habitat restoration.
- Uses native plants to break waves gently
- Filters wastewater to reduce nitrogen
- Creates habitat for endangered salt-marsh harvest mice
What happened
The Palo Alto Horizontal Levee Pilot Project represents an innovative departure from traditional levees. Instead of a steep, barren embankment, this levee features a gently sloped surface densely planted with more than 35 native species. Its unique design allows it to interact with tidal waters in a way that mimics natural estuaries, helping to reduce wave energy more gently compared to conventional rock barriers.
Installed in 2017 and inspired by earlier projects like the Oro Loma levee near Hayward, the Palo Alto levee also integrates treated wastewater irrigation. This process helps plants remove excess nitrogen before water flows back into the Bay, enhancing overall water quality without discharging untreated substances.
Why it feels good
This approach not only offers a practical answer to rising sea levels but also benefits local wildlife. The levee’s thriving vegetation provides vital habitat for native species, notably the endangered salt-marsh harvest mouse — affectionately nicknamed “salties.” By restoring the marsh environment these small creatures depend on, the levee supports biodiversity and offers hope for their survival amid climate challenges.
Beyond ecological gains, the project is fostering collaborations between scientists, city engineers, and nonprofits to collect valuable data on how such green infrastructure affects flood control, water health, and community recreation. This research could pave the way for wider adoption of living levees despite their higher initial costs.
What to enjoy or watch next
Over the coming five years, researchers will closely monitor the Palo Alto horizontal levee’s impacts on both environmental and social aspects. Observers can anticipate new insights into how effectively these levees protect shorelines while enhancing estuarine ecosystems. The outcomes may influence future coastal protection strategies not just in California but in other vulnerable regions around the world.
Meanwhile, residents and visitors to the Baylands can enjoy the peaceful scenery and vibrant wildlife supported by these living levees. Watching native birds glide overhead and witnessing natural landscapes flourishing provides a tangible reminder that nature-based solutions hold a key to resilient, sustainable communities.