The proposed Ocean Beach Climate Change Adaptation Project would address shoreline erosion, severe coastal storm and wave hazards, and sea level rise which threaten city infrastructure, coastal access and recreational facilities, and public safety. The project area generally encompasses the portion of San Francisco’s Ocean Beach extending south from Sloat Boulevard to the northern edge of the Fort Funston bluffs, and the Great Highway from Sloat Boulevard to Skyline Boulevard, along with portions of Ocean Beach to the north and portions of Fort Funston to the south. Major project components include: (1) permanently closing the Great Highway between Sloat and Skyline boulevards, and reconfiguring affected intersections and San Francisco Zoo parking access; (2) removing rock and sandbag revetments, and rubble and debris from the beach, and reshaping the bluff to provide a more gradual transition between beach and upland areas, and planting native vegetation; (3) constructing a multi-use trail and Americans with Disabilities Act improvements to existing trail segments, beach access stairway, coastal access parking, and restrooms, and enhancing habitat; (4) constructing a buried wall to protect existing wastewater infrastructure from shoreline erosion; and (5) long-term beach nourishment (sand replenishment). The project is a collaborative, multi-agency initiative involving the San Francisco Public Utilities Commission (SFPUC), San Francisco Recreation and Parks, San Francisco Public Works, San Francisco Municipal Transportation Agency (SFMTA), and the Golden Gate National Recreation Area, a unit of the National Park Service. The city is also coordinating with the U.S. Army Corps of Engineers (Corps) on the potential for beneficially using Corps dredged sand for the project’s beach nourishment program.
For long-term beach nourishment the City and County of San Francisco (the city) has identified two primary sand sources and placement methods. The first is the San Francisco Harbor – Main Ship Channel, which is dredged annually by the Corps as part of that agency’s ongoing federal navigation channels maintenance program. Under this “large placement” option a Corps dredge would pump up to 575,000 cubic yards of sand in a slurry form onto the beach, rather than disposing of it offshore. The second primary source is North Ocean Beach (i.e., north of Lincoln Boulevard). Under this “small placement” option the city would continue its practice of excavating and trucking excess sand from North Ocean Beach to South Ocean Beach and placing coarse sand from other sources as a top layer (referred to as sand backpass). The small placement option would involve trucks dumping up to 85,000 cubic yards of sand onto the beach and bluff. The city could also obtain a smaller volume of sand from a commercial vendor if necessary.
The type and frequency of sand placements would depend upon sand availability (i.e., Corps and North Ocean Beach) and shoreline conditions (e.g., sea level rise and related erosion rates). Sand placements would occur about once every four to 10 years, generally in summer or fall.