An innovative experimental horizontal levee in California wins the award for Outstanding Environmental Project

A re-imagining of how a levee looks and what it can offer

A re-imagining of how a levee looks and what it can offer

Could a wedge of gravel, mud and grass, offer a regional solution to flood risk from sea rise? Instead of a vertical wall to protect against storm surges, a full-scale experimental horizontal levee project in Oro Loma Sanitary District, San Francisco, under the so-called ‘Horizontal Levee project’ is trying to find out. The horizontal levee, which uses vegetation on a slope to break waves, is also irrigated by treated wastewater. The native plants and wildlife that live on horizontal levees can thrive while helping to further polish cleaned wastewater from treatment plants. In early October, friends of the San Francisco Estuary honored Oro Loma Sanitary District for its work, with the Outstanding Environmental Project Award, presented at the 13th biennial State of the San Francisco Estuary Conference.

The ‘Horizontal Levee project’

The construction of the Horizontal Levee project started in 2015 and was completed in April 2017. It is located on the southern edge of the existing water pollution control facility jointly owned by Oro Loma and Castro Valley Sanitary Districts. The project was also recognized earlier this year by the California Association of Sanitation Agencies (CASA) for Outstanding Capital Project of 2017. “We are pleased to be recognized for the Horizontal Levee project,” said Oro Loma General Manager Jason Warner. “This was a huge undertaking by staff, the project team, and volunteers, and we hope that our levee is a prototype for future large-scale projects that will help guard our shores against rising seas. Protecting the environment is one of our core values and this project will help advance the science of sea rise.”

For a more in depth overview, read the Oro Loma and Castro Valley Sanitary Districts to test Experimental Levee, or the Save the Bay Horizontal Levee Report. 

Source: Civil+Structural engineer magazine