Pine Lake Park Slope Restoration Project
Overview
The Vale Parking lot and Pine Lake Park dog meadow are open but the paved roadway may experience temporary closures when equipment is being brought in or out of the work area. The San Francisco Recreation and Parks Department may also close the area to the public on days with sustained high winds. Please visit their website for wind-related closure information.
March 2025:
Restoration work on the lower half of the impacted slope is largely complete. Work on the upper half of the slope is well underway. Improvements are being made to the west of the dog park to restore decades-old drainage works that had become buried. This will assist in allowing the park to dry out more rapidly during rainy season.
Please avoid the fenced-in area adjacent to the dog park where staging of materials and equipment is taking place. The dog park will remain open during the work being performed. Due to climactic conditions in the park, please exercise caution when in the vicinity of the work site.
NOTE: Through the duration of rainy season, our contractor will ensure that the slope is covered during rain events in order to avoid any concerns about run off (see photos below).
Progress Photos:
March 2025
Our removal of hazard trees in Pine Lake Park is complete.
Improving drainage on the western end of Pine Lake Park
Slope restoration continues
February 2025
Retaining wall mid-way up the slope (will not be visible when project is complete)
Soil compaction
January 2025
Building up the slope
Progress on the lower end of the slope
December 2024
Retaining wall construction
Slope protection during atmospheric river rain event
Preparing slope for installation of steel beams
Steel beams after installation on slope
Cement poured above retaining wall
November 2024
Restoration of soil on slope, and materials being prepared for the retaining wall
October 2024
Overview of work area and dog park
Machinery used to remove debris from the soil so that it may be reused
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Project Background
The Sunset Supply Pipeline is one of several major water transmission lines that bring water to San Francisco's drinking water reservoirs. This pipeline is 60" in diameter and was placed into service shortly after World War II. The air valve that failed was 8" in diameter, and the transmission line itself was not breached.
Map showing approximate area along the Sunset Supply transmission line where air valve is located (in red)
Background:
On March 8, 2024, an 8-inch air valve connected to a 60-inch water transmission line failed, just below the end of the 1700 block of Wawona Street, above the Pine Lake Park dog park.
That transmission line feeds water from our treatment plant on the San Francisco Peninsula to the Sunset Reservoir, which is one of the largest serving the residents of the city.
Water streaming from the air valve caused a geyser above the area which then flowed down a steep slope into the park, scouring a path to the park below until the crews onsite were able to shut the leak down.
The week of March 11, 2024 the SFPUC identified a construction contractor and an engineering consultant who will work with the agency to determine a scope and schedule for repairs, including the hillside and the dog park area.
Map is approximate and not to scale. Blue area is the location of the impacted slope. Yellow area is the debris field.
The first phase of work to prepare for restoration of the area was to remove hazardous trees. That included all trees that became dangerously undermined by the scouring action of the water. This work began on March 11th, 2024 and was completed on March 21st, 2024.
The second phase of work involved covering the affected area of the slop with plastic sheeting to prevent further erosion. That work was completed on March 22nd, 2024.
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Photos
Filtering debris to provide clean material for re-use on the slope repair, October 9, 2024
Work area prior to "grubbing of slope", September 30, 2024
Covering the slope with temporary waterproofing, March 22, 2024
View of washout area and debris field, March 14, 2024
Washout area, March 12, 2024
The day of the valve failure, March 8, 2024
- Project Materials