California Water Service

California Water Service (Cal Water) is the largest subsidiary of the California Water Service Group. Cal Water is the largest investor-owned American water utility west of the Mississippi River and the third largest in the country. Formed in 1926, the San Jose-based company serves more than 477,900 customers through 28 Customer and Operations Centers throughout the state.

Contact Information

Customer Support Services
(Corporate headquarters)
1720 North First Street
San Jose, CA 95112-4508
(408) 367-8200
infoGO@calwater.com