July 24, 2024

Visitors encouraged to heed all construction-related signage as work commences 

Mt. Tam Watershed – The Pine Mountain Tanks Project, a multi-year effort to replace the aging Pine Mountain Tunnel’s use as a water storage facility with two, 2-million-gallon concrete tanks, is entering its Year 2 construction window. 

After a planned pause related to weather and other environmental factors, work on the project, located near Bolinas-Fairfax and Sky Oaks roads, will resume in August. Since construction began in the summer of 2023, crews have worked to excavate the site and install a retaining wall in preparation for the eventual installation of the pre-stressed concrete tanks. This excavation and retaining wall work will continue during Year 2 of construction, which will last through Jan. 31, 2025. 

Road and trail access will be limited near the construction site on weekdays during construction hours, and Mt. Tam visitors are encouraged to review watershed visitor notices before visiting and heed all construction-related signage as work commences. The complete tank installation project is expected to continue, on a seasonal basis, through January 2029. 

The Pine Mountain Tanks Project will ultimately bolster the District’s water supply resiliency by improving seismic stability and water quality, boosting firefighting capabilities on the watershed and increasing water system capacity for Ross Valley. This project is one of more than a dozen major water infrastructure projects kicking off or continuing this summer as Marin Water works to maintain and improve its water system through strategic investments in the District’s water system. 

More information about the Pine Mountain Tanks Project can be found at marinwater.org/PMTtanks.