San Francisco Seawall Project Approved to Protect Ocean Beach

The California Coastal Fee just lately accredited a $175 million venture that can defend San Francisco’s Ocean Seaside in addition to key elements of the town’s wastewater infrastructure imperiled by climate-induced erosion of the coastal bluffs.

The Ocean Seaside Local weather Change Adaptation Venture accredited on Nov. 14 features a 3,200-ft-long buried seawall at Ocean Seaside to guard the sewer system infrastructure, which incorporates the town’s Lake Merced Tunnel and a close-by recycled water facility.

“These long-term enhancements will defend the important wastewater infrastructure in danger,” Anna Roche, San Francisco Public Utilities Fee venture supervisor, stated in an announcement. “However equally vital, this venture provides a chance for the town to drastically enhance public use and accessibility alongside the coast south of Sloat Boulevard.”

As soon as the seawall is accomplished the dunes and associated habitats will probably be restored. Sustaining the restored seaside and the seawall will value roughly $1 million yearly, in response to the fee. Relocating the wastewater infrastructure would value $1.6 billion, in response to San Francisco Water Energy Sewer.

The San Francisco Public Utilities Fee’s proposal requires rerouting Nice Freeway away from the narrowest a part of the seaside, constructing a greater than 1-mile-long multi-use public path with views of the Pacific Ocean the place the freeway presently runs and a seaside nourishment venture that options new sand because the shoreline will get widened 78 toes.

Extra parts contain maximizing open house and public leisure entry within the space by habitat restoration. A Coastal Improvement Allow for the venture was accredited in November.

Development on the venture is anticipated to begin in late 2027.

Coastal erosion on Ocean Seaside has severely impacted highway and water infrastructure.

Picture courtesy California Coastal Fee

The fee report’s on the Ocean Seaside venture says that shoreline erosion is threatening essentially the most seaward part of the fee’s mixed sewer system, the Lake Merced Tunnel, a 14-ft-diamter pipe positioned underneath the Nice Freeway. “With rising sea ranges and extra intense storms, erosion is just anticipated to worsen,” the report particulars,” which amplifies the urgency to guard vital coastal infrastructure, habitats and the seaside itself.”

The Nice Freeway was initially constructed in 1929 and has been modified many occasions since, together with throughout the 1993 building of the tunnel pipeline that mixes for stormwater/wastewater circulation and overflow storage.

As a part of its overflow perform, the tunnel holds untreated mixed stormwater and wastewater flows during times when the Oceanside Water Air pollution Management Plan is unable to deal with the amount of inflow, equivalent to throughout main storm occasions. If the tunnel’s capability ever fills, extra water heads to the Pacific Ocean through a pipe that runs 3.5 miles offshore.  

Along with mitigating erosion impacts, the brand new venture will defend the tunnel with armoring.

Rerouting Nice Freeway away from the seaside between Sloat and Skyline boulevards contains enhancements to 2 intersections whereas different wants embrace rerouting a bus layover and turn-around space and reconfiguring the San Francisco Zoo parking entrance. The freeway’s transfer additionally incorporates a new seaside entry stairway and outlooks, public restrooms and 60 parking areas on the south finish of the venture changing the present 30 close by that can get eradicated with the modifications.

Habitat restoration contains eradicating revetments and particles beforehand used to scale back erosion, reshaping the bluff to extend accessibility to open house, new native vegetation planting and sand replenishment.