Rising sea levels and climate change threaten to swamp not only bayshore communities, but also 50 years of efforts to restore San Francisco Bay. But instead of throwing up their hands, scientists and engineers have designed a promising fix for threatened shorelines: the ecotone slope.
Also known as a horizontal levee, this wide wedge of gravel, mud, and native plants could help protect many vulnerable bayshore communities from rising sea levels. Placed between the Bay and a flood control levee, it absorbs wave action, helps prevent threatened species from drowning, and polishes wastewater to an impressive degree of purity.
In 2015, the Oro Loma Sanitary District constructed an experimental ecotone slope along the bayshore of San Lorenzo/Hayward. The slope has been divided into experimental zones and planted with different palettes of native plants. Pipes threaded through the heart of the slope provide irrigation with wastewater from the adjacent Oro Loma Sanitary District sewage treatment plant. If built alongside only a quarter of the Bay Area’s 570 miles of existing levees, ecotone slopes could increase upland bayshore habitat by more than 5,000 acres.
Tour this revolutionary new approach to flood protection, wastewater processing, and habitat restoration with our expert guides, who will include
Peter Baye, coastal ecologist, botanist, and wetland restoration expert
Aidan Cecchetti, PhD candidate, civil and environmental engineering, UC Berkeley
Jason Warner, General Manager, Oro Loma Sanitary District
Additional links:
Project brochure, “Oro Loma and Castro Valley Sanitary districts to test experimental levee”
“Nudging natural magic,” Dec. 2017, Estuary News
