Private Investor-Owned Utility
California Water Service Company - Bayshore District, San Mateo System
Serving San Mateo and the Cal Water Bayshore District
Population served
102,348
State system code
FIPS 06
Billing frequency
A dedicated this detail was not publicly posted. Cal Water's reviewed public Bayshore pages identify the tariff as a per-meter-per-month service charge but do not state one universal bill cadence for every San Mateo account.
Provider briefing
How this utility’s billing works
California Water Service Company - Bayshore District, San Mateo System operates as a private investor-owned utility serving San Mateo and the Cal Water Bayshore District. Customers should use the provider’s current account-specific bill and official customer-service instructions as the final authority for deadlines, balances, and service requests.
The published water-rate framework is described as CPU C-regulated monthly service charge plus increasing block residential consumption tiers. Effective July 1, 2026 for the Bay Area Region residential metered schedule, a 5/8 x 3/4-inch meter has a $34.47 monthly service charge; usage is $4.2083 per CCF for 1-6 CCF, $16.8152 for 7-9 CCF, $21.0842 for 10-13 CCF and $25.2184 above 13 CCF. One CCF is approximately 748 gallons. San Mateo customers may also see a 1.350% San Mateo business-license surcharge and CPUC-approved surcharges or credits.. Bills are generated a dedicated this detail was not publicly posted. cal water's reviewed public bayshore pages identify the tariff as a per-meter-per-month service charge but do not state one universal bill cadence for every san mateo account., and a typical residential cost reference is For a typical 5,000-gallon San Mateo account, approximately $71.22 for Cal Water service before taxes, CPUC surcharges and any separate local wastewater bill: $34.47 monthly service charge plus roughly $36.75 for 6.684 CCF under the July 1, 2026 BAR-1-R tiers. The calculation is an estimate because Cal Water bills in CCF and the applicable tariff components may vary by account.. These descriptions are useful planning benchmarks; actual charges can change with meter size, usage, sewer averaging, local taxes, drought stages, or account-specific fees.
Wastewater and sewer calculation
Cal Water's Bayshore District supplies drinking water; the reviewed official tariff and district pages do not establish a universal San Mateo wastewater formula. Sewer charges, if applicable, are generally administered by the local wastewater agency rather than included in the Cal Water water tariff; customers should verify the separate sewer statement and winter-averaging rules with the responsible local agency.
Meter and infrastructure notes
A dedicated this detail was not publicly posted. The reviewed current Bayshore pages identify 18 storage tanks and 30 booster pumps in the San Mateo system and provide tariff billing by CCF, but do not identify residential AMI/AMR technology, transmission interval or a universal route-reading schedule.
Emergency water support
Report a leak or water emergency
A dedicated this detail was not publicly posted. The reviewed Bayshore district page provides local customer-center assistance and the automated payment number but does not display a dedicated 24/7 San Mateo emergency telephone number. Customers should use Cal Water's district contact route for active leaks or service hazards.
Official starting point
Choose the right next step
Reading this profile
A practical reference for San Mateo and the Cal Water Bayshore District
California Water Service Company - Bayshore District, San Mateo System is listed here as a private investor-owned utility. The profile separates account actions—such as paying a bill or requesting service—from explanatory material about rates, meters, wastewater, leaks, and delinquency.
Because utility rules can vary by account class, meter size, service address, billing date, and local ordinance, treat the published bill and current provider website as the final authority. Use this profile to locate the correct channel and prepare better questions for customer service.
If your issue is urgent, start with the provider’s emergency number or official payment route rather than waiting for an email response. Keep a written record of calls, confirmation numbers, notice dates, and documents you submit.