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Ocean Beach, one of the gems of the San Francisco landscape, is facing significant challenges. In the 1980’s and 1990’s, in response to the Clean Water Act, the San Francisco Public Utilities Commission (SFPUC) built the Oceanside Treatment Plant (OSP) and associated infrastructure to protect coastal water quality from pollution. The work included improvements to the natural conditions, such as improved public access to the beach, addition of dune-like sand embankments and improvement to public bathrooms. However, chronic erosion problems at south Ocean Beach threatens the Lake Merced Tunnel (LMT), one of SFPUC’s critical wastewater conveyance and storage facilities located under the Great Highway south of Sloat Boulevard.
In support of a comprehensive solution to the erosion problem, the SFPUC actively participated in the development of the 2012 Ocean Beach Master Plan (OBMP). The OBMP, led by SPUR, was an interagency effort to develop a sustainable long-term vision for Ocean Beach, addressing public access, environmental protection and infrastructure needs in the context of erosion and climate-related sea level rise.
The OBMP presents a framework for understanding the wide range of issues and challenges at Ocean Beach and identifies a series of recommendations for balancing the many priorities and objectives identified by local agencies and stakeholders, including protecting critical wastewater infrastructure south of Sloat Boulevard from chronic erosion hazards.
In order to carry out the OBMP recommendations, the SFPUC has been working to develop short and long-term coastal protection measures and a management strategy that protects critical wastewater infrastructure and promotes environmental stewardship. These short and long-term measures would be implemented as a two-phased approach.
Phase I (Short-term strategies; 2015 – 2021) is being completed under a multi-year Coastal Commission permit and is a continuation of sand management activities conducted in cooperation with the National Park Service (NPS). These efforts are a repeat of the successful short-term actions taken in past years in which excess sand in front of the O'Shaughnessy Seawall (north Ocean Beach) was transported to erosion hotspots south of Sloat Boulevard (south Ocean Beach). Also included in this permit is the added ability to utilize/place sand bags on the beach. Together these measures will protect the LMT and associated critical infrastructure from risk of exposure due to erosion until the long-term is ready for implementation. The short-term strategies would be implemented on an as-needed basis; based upon monitoring of pre-established thresholds for intervention.
This year’s project includes the following components:
- Sand Backpass – Excavate approximately 70,000 cubic yards of sand from north Ocean Beach along the O’Shaughnessy Sea Wall and place it in two erosion hot spots south of Sloat Boulevard.
- Wind-Erosion Control Measures – Natural brush fencing and/or other measures will be installed to reduce windblown sand from being transported onto the parking lots and Great Highway south of Sloat Boulevard.
Work Hours and Traffic Detours
- Work will occur weekdays from 7am – 5pm;
- Southbound traffic on the Great Highway will be detoured to Sunset Boulevard between Lincoln Way and Sloat Boulevard;
- Northbound traffic and Muni bus stops in the same stretch will not be affected;
- Northbound traffic will experience a lane reduction between Highway 35 and Sloat Boulevard.
To protect public safety, access to the beach will be limited in certain areas when work is underway. Parking areas at the south end of the O’Shaughnessy Seawall and the overlook parking areas south of Sloat Boulevard will not be available during construction.
Phase II (Long-term strategies; anticipated in 2021) would address public access, environmental protection and infrastructure needs in the context of erosion and climate-related sea level rise. The work is expected to involve the implementation of coastal management strategies that include managed retreat, beach nourishment, and structural protection through adaptive management. Alternatives, including removal of the LMT, are currently being analyzed to determine the best option to carry forward the design. One option involves the removal of existing coastal armoring and installation of a subsurface, low-profile structure that would protect vulnerable segments of the LMT south of Sloat Boulevard. The design, environmental review, and permitting expected to be completed by 2021.
Conceptual Rendering of Long-term Project:
For more information on the Ocean Beach Master Plan visit SPUR’s website.
Anna M. Roche
Climate Change & Special Projects Manager
Wastewater Enterprise – Planning & Regulatory