In-person service is not available at this location; however, our customer service representatives are happy to serve you by phone or email. In-person and other payment options are detailed on the Payment Options page.
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.
Frequently Asked Questions
What forms of payment does Cal Water accept?
You can pay your Cal Water bill with cash, a check, a money order, a credit card, a debit card, or bank account. However, available payment options vary depending on the payment location or method. For more detail, see the Payment Options page.
What is the Customer Assistance Program (CAP)?
Cal Water offers a Customer Assistance Program (CAP — formerly LIRA) to customers who meet income guidelines. Qualifying customers receive a discount on their monthly service charge. You can visit the CAP page to see if you qualify and download an application form. If you live in a single-family residence, you can also apply online.
What should I do if my bill seems higher than usual?
See the High Bills page for more information and suggestions.
How do I turn off the water supply to my house in the event of a break in my plumbing or a repair?
You can interrupt the flow of water to your home by turning off your house valve. House valves are usually located beneath a faucet outside the home, most typically near the faucet for the garden hose. If you cannot find your house valve, please contact your local Customer Center for assistance.
Payment Mailing Address
California Water Service P.O. Box 7229 San Francisco, CA 94120-7229
Automated Payment Number
(888) 598-9824
Rebates
Rates
Customer Assistance: We’re Here to Help
Cal Water has services and programs to assist you in a variety of circumstances.
