Alameda has been dealing with a structurally inadequate shoreline along its south shore ever since a developer pumped in sand from the Bay to create more land for homes and a shopping center in the mid-1950s. The developer left Alameda with an embankment that didn’t hold up well.
In 1976, barely 15 years after the development was completed, the City and the East Bay Regional Park District (EBRPD) asked the federal government to fund a major Army Corps of Engineers study of alternatives to deal with erosion threatening the street. The City and EBRPD chose the beach alternative that created today’s Alameda Beach in the early 1980s.
The existing remedy of a beach is now facing more extreme weather events causing major erosion and sea level rise. As part of its planning efforts for both immediate and long-term adaptation of the shoreline, the City recently submitted a grant application to the San Francisco Bay Restoration Authority to pay for designing new adaptation measures along the shoreline. State law now requires that all communities around the Bay have sea level rise shoreline adaptation plans by 2034.
Called the Alameda South Shore Adaptation Project – Concept Design, its goal is not to produce construction drawings but rather overall concepts that will meet the new state requirements for shoreline adaptation. The study will be broken down into four concepts: (1) Bird Sanctuary and Bay Trail Concept; (2) Mudflat and Eelgrass Concept; (3) Stormwater and Lagoon Concept; and (4) Beach Nourishment Concept.
Bird Sanctuary and Bay Trail Concept
The Elsie Roemer Bird Sanctuary is at risk of being lost under water and will be evaluated for potential measures to enhance the existing salt marsh intertidal habitat through elevation changes and space for it to migrate as sea level rises. It will also seek to bolster the Bay Trail for sea level rise adaptation and ADA accessibility from the Bay Farm Bridge to the bird sanctuary.
Mudflat and Eelgrass Concept
The mudflat and eelgrass concept will explore opportunities to expand mudflats and the sizable offshore eelgrass bed. “The existing patch of eelgrass adjacent to Alameda’s south shore is about 340 acres,” states the grant application. “Nevertheless, rising water levels and rising temperatures are likely to reduce the suitability of this area for eelgrass in the future, making proactive efforts necessary to protect and expand this eelgrass patch.”
Eelgrass is considered a keystone subtidal species that enhances biodiversity, reduces sediment loss and improves sand management activities. The slender blades of grass are a favored habitat for fish, such as herring, to deposit their eggs…