Costa Mesa water and sewer rates
Who supplies water to Costa Mesa houses, what it costs, and how the sewer charge works.
Mesa Water District
Mesa Water District (rates effective January 1, 2026): a bi-monthly Basic Charge of $38.75 for a 5/8-inch meter plus $6.38 per unit of potable water (1 unit = 100 cubic feet or 748 gallons). A separate Capital Charge based on meter size is collected on the property tax bill.
| Use a month | Price per unit (CCF, 748 gallons) |
|---|---|
| Fixed charge | $19.38 a month |
| 0 to more | $6.38 |
- Source
- 100% local groundwater from the Orange County Groundwater Basin, pumped from Mesa Water's nine wells, plus deep amber-tinted groundwater treated at the Mesa Water Reliability Facility. Imported water from MWDOC is a backup supply.
- Hardness
- Total hardness averaged 113 ppm as CaCO3 (6.6 grains per gallon) in Mesa Water's groundwater in 2025, with a range of 20.6 to 293 ppm.
- Lead
- In the 2023 at-the-tap testing of 50 homes, lead was detected in two samples; one exceeded the action level and its re-sample was not detected. Mesa Water's 2024 inventory found no lead or galvanized service lines requiring replacement.
Sewer
Costa Mesa Sanitary District's wastewater collection charge for a single-family home is $118.43 a year (FY 2026-27), a special assessment on the property tax bill. OC San, which treats the wastewater, charges its own regional sewer fee on the property tax bill.
Ways to pay less
- Sewer lateral inspection rebate. Costa Mesa Sanitary District rebates up to $200 for a CCTV video of your sewer lateral from a ground-level clean-out (up to $250 from a roof vent or toilet flange) or up to $500 for installing a ground-level clean-out. Approval is needed before any work, once every five years, and funding is limited. How: Apply on CMSD's Sewer Inspection Rebate Program page and wait for a confirmation number before hiring a plumber.
- Water-saving rebates. Mesa Water offers residential rebates for high-efficiency clothes washers, high-efficiency toilets, water-saving sprinkler nozzles, smart sprinkler timers and more. How: See the full list on Mesa Water's Rebates page.
Dates
| When | What |
|---|---|
| Jan 1, 2027 | Mesa Water rates rise: $41.47 bi-monthly Basic Charge for a 5/8-inch meter, $6.83 per unit of water, and a $284 yearly Capital Charge for a 5/8-inch meter. |
Pay or manage it
Sources
- Costa Mesa Sanitary District FY 2026-27 solid waste and wastewater collection rates
- Costa Mesa Sanitary District: sewer FAQs
- Costa Mesa Sanitary District: sewer inspection rebate program
- Mesa Water District: 2026 rates and fees
- Mesa Water District: rates and fees
- Mesa Water District Resolution No. 1584 (water rates 2024-2028)
- Mesa Water District FY 2024 cost-of-service and rate study
- Mesa Water District: billing explanation
- Mesa Water District 2026 Consumer Confidence Report
- Mesa Water District: rebates
- Irvine Ranch Water District: about us
- OC San: sewer rates and claim forms
- Metropolitan Water District: 2026/27 water standby charge resolution
Checked October 22, 2026. Every number here comes from the public sources listed, matched by our checker.
Rates change every year; this page shows when it was last checked. Nothing here is legal, tax or insurance advice.