Blog > Who Provides Water in Your Silicon Valley City? Every City, 2026
Setting up water at a new home? In Silicon Valley the answer depends on the city, and in a few cities on the street: some cities run their own water utility, some are served by an investor-owned company like San Jose Water or Cal Water, and a few are split among several systems. Here’s who delivers drinking water in each of the 31 cities we cover, with the official source for each.
The short answer
- San Jose Water serves Campbell, Los Gatos, Monte Sereno, Saratoga, most of San Jose and part of Cupertino. Its parent company, formerly SJW Group, is now called H2O America; the utility is still San Jose Water.
- Cal Water (California Water Service) serves Los Altos, Atherton, Portola Valley and most of San Mateo and South San Francisco, and parts of Cupertino, Los Altos Hills, Menlo Park, San Carlos, Woodside and a few small areas of Mountain View, Sunnyvale and Daly City.
- City-run utilities serve Gilroy, Morgan Hill, Milpitas, Palo Alto, Santa Clara, most of Mountain View and Sunnyvale, Burlingame, Hillsborough, Millbrae, San Bruno, Redwood City, most of Daly City, most of East Palo Alto and part of Menlo Park.
- Districts serve Belmont (Mid-Peninsula Water District), Foster City (Estero Municipal Improvement District), two-thirds of Los Altos Hills (Purissima Hills) and part of South San Francisco (Westborough).
- San Jose has three providers, and two of them both name Edenvale and Coyote Valley, so check by address.
Setting up a new home?
Santa Clara County
| City | Drinking water | Official source |
|---|---|---|
| Campbell | San Jose Water | source |
| Cupertino | Three systems: Cal Water (northeastern part of the city), San Jose Water (southeastern part) and the city-owned Cupertino Municipal Water System (western part), which San Jose Water runs under a lease | source |
| Gilroy | City of Gilroy | source |
| Los Altos | Cal Water (Los Altos Suburban District) | source |
| Los Altos Hills | Purissima Hills Water District (about two-thirds of the town) and Cal Water (the rest) | source |
| Los Gatos | San Jose Water | source |
| Milpitas | City of Milpitas | source |
| Monte Sereno | San Jose Water | source |
| Morgan Hill | City of Morgan Hill | source |
| Mountain View | City of Mountain View for most of the city; Cal Water in small areas from Grant Road east around Highway 85 | source |
| Palo Alto | City of Palo Alto Utilities | source |
| San Jose | Three providers by area (see below) | source |
| Santa Clara | City of Santa Clara Water & Sewer Utilities | source |
| Saratoga | San Jose Water | source |
| Sunnyvale | City of Sunnyvale for most of the city; Cal Water in several small areas from Grant Road east to Highway 85 | source |
San Mateo County
| City | Drinking water | Official source |
|---|---|---|
| Atherton | Cal Water (Bear Gulch District) | source |
| Belmont | Mid-Peninsula Water District | source |
| Burlingame | City of Burlingame | source |
| Daly City | City of Daly City for almost every property; Cal Water (Bayshore District) for a small part of the city | source |
| East Palo Alto | City of East Palo Alto water system, run by Veolia (about 80% of connections); Palo Alto Park Mutual Water Company and O’Connor Tract Co-operative Water Company serve the rest | source |
| Foster City | Estero Municipal Improvement District (run by the City of Foster City) | source |
| Hillsborough | Town of Hillsborough | source |
| Menlo Park | Menlo Park Municipal Water (Sharon Heights and areas east of El Camino Real); Cal Water (Downtown and West Menlo); O’Connor Tract Co-operative (a small section of the Willows); Palo Alto Park Mutual (fewer than ten addresses on Menalto Avenue) | source |
| Millbrae | City of Millbrae | source |
| Portola Valley | Cal Water (Bear Gulch District) | source |
| Redwood City | City of Redwood City; Cal Water (Bear Gulch District) serves some nearby areas, so check by address | source |
| San Bruno | City of San Bruno | source |
| San Carlos | Cal Water (Bayshore District) and Mid-Peninsula Water District, with Redwood City water serving a portion; check by address | source |
| San Mateo | Cal Water (Bayshore District), the provider the city names; Foster City’s Estero district serves a part of the city; check by address | source |
| South San Francisco | Cal Water (Bayshore District); Westborough Water District in the area west of I-280 to Skyline Boulevard (about one square mile) | source |
| Woodside | Cal Water (Bear Gulch District) and Redwood City water for portions of the town; check by address | source |
San Jose, area by area
- San Jose Municipal Water System (city-owned): Alviso and San Jose north of Trimble Road, Evergreen, Edenvale and Coyote Valley.
- Great Oaks Water Company: the Blossom Valley, Santa Teresa, Edenvale, Coyote Valley and Almaden Valley area.
- San Jose Water: the rest of the city.
Both Muni Water and Great Oaks name Edenvale and Coyote Valley, so check your address with San Jose Municipal Water, Great Oaks or San Jose Water. Sources: Valley Water’s Find My Water Retailer table and the providers’ own sites.
Where the water comes from
- On the Peninsula, most systems buy treated water from the San Francisco Public Utilities Commission’s Hetch Hetchy system, according to the Bay Area Water Supply and Conservation Agency (BAWSCA).
- In the South Bay, many systems buy from Valley Water and pump local groundwater; Morgan Hill and Gilroy rely on wells.
- Some cities blend both, such as Sunnyvale, Mountain View, Santa Clara and Milpitas.
How to start service
- Call the provider for your address a week or two before closing; city utilities often bill water with sewer and garbage.
- Not sure which system serves a street? Your escrow officer or the seller’s last bill will show it, and each provider’s site has a service-area map or address lookup.
How we checked
Each provider comes from the city’s or town’s own website, the provider’s site, Valley Water’s retailer table or BAWSCA’s member profiles, read on October 29, 2026. Several city sites couldn’t be read automatically; for those we used Valley Water, BAWSCA and the providers’ own pages, and where none of them states which part of a city each system serves, we say to check by address. Unincorporated pockets can have different providers than the city next door.
Moving here?
We’ll help you line up the utilities, the move-in details and the home itself. Call (408) 373-1660 or (650) 383-8606, or book a call. Commissions are negotiable, and we offer bundled services, so ask us what’s included.