District Information

Serving Atherton, Bear Gulch, Kings Mountain, Los Trancos, Portola Valley, Skyline, and Woodside, and portions of Menlo Park and Redwood City

Cal Water has provided high-quality water utility services in the communities of Portola Valley, Woodside, Atherton, and portions of Menlo Park, Redwood City, and San Mateo County since 1936. Skyline County's water system became part of the Bear Gulch district in 2009, Skylonda Mutual became part of our system in 2023, and Kings Mountain was added in 2024. To meet our customers' needs, we use a combination of local surface water and surface water purchased from the City and County of San Francisco (SFPUC). The local surface water, about 11% of our total supply, comes from our 1,200-acre watershed in the Woodside hills; it is collected and treated at our reservoir and treatment plant in Atherton. The remaining 89% of our supply is purchased from the SFPUC.