In Costa Mesa, Mesa Water District or IRWD handles the water supply to your meter, the Costa Mesa Sanitary District runs the public sewer, SoCalGas handles gas leaks, and a licensed plumber handles the pipes on your property. This guide sorts out who to call first.
Call (657) 669-4766Request service
Written and fact-checked by John, editor, MBA in marketing
Updated against City, utility and state sources
For a water main break or problem at the meter, call your water district: Mesa Water at 949-631-1200 (after hours press 9 for Costa Mesa Police) or IRWD at 949-453-5300. For public sewer issues call the Costa Mesa Sanitary District at (949) 645-8400. For a gas smell, leave and call SoCalGas at 1-800-427-2200. For leaks, clogs and heaters inside your property, call a plumber.
Here is every number most Costa Mesa households need for water, sewer, gas and electric problems, with what each one actually handles.
Costa Mesa does not run its own water or sewer utility the way some cities do. Water comes from a special district, either Mesa Water District or the Irvine Ranch Water District depending on your address. Sewage is collected by the Costa Mesa Sanitary District, which sends it to OC San for treatment. Building permits come from the City. Knowing who does what saves a lot of time when something goes wrong at 2 a.m.
We checked each number below against the organization's own website or published documents in late 2026. Phone numbers change, so if one does not connect, look it up on the agency's site.
| Organization | Call them for | Number and details |
|---|---|---|
| Mesa Water District | Water service for most of Costa Mesa: main breaks, leaks at the meter, no water, billing, start or stop service, water quality | 949-631-1200. After hours, press 9 to reach Costa Mesa Police, or call 714-754-5251. Water quality: 949-574-1031. Backflow: 949-574-1000. Office: 1965 Placentia Ave, Mon to Thu 7:30 a.m. to 5:00 p.m., Fri 8:00 a.m. to 3:30 p.m. |
| Irvine Ranch Water District (IRWD) | Water service for the parts of Costa Mesa it serves | 949-453-5300 |
| Costa Mesa Sanitary District (CMSD) | Public sewer mains, sewer overflows from manholes, sewer permits, curbside trash for homes and buildings up to 4 units | (949) 645-8400. 290 Paularino Ave. Mon to Thu 7:30 a.m. to 4:30 p.m., every other Friday 7:30 a.m. to 3:30 p.m. Permits: permits@cmsdca.gov |
| SoCalGas | Gas leaks, gas smell, damaged gas lines, gas service | 1-800-427-2200. Leave the area first and call from a safe place. Call 911 if anyone is in danger. |
| Southern California Edison (SCE) | Downed power lines, electrical hazards | Call 911 first for a downed line, stay at least 100 feet away. Safety issues: 1-800-611-1911. |
| City of Costa Mesa Building Safety | Building and plumbing permits, inspections, permit questions | 714-754-5273. 77 Fair Drive, 2nd floor. buildingpermit@costamesaca.gov. Permits online through TESSA. |
| 811 (DigAlert) | Marking underground utility lines before digging | Call 811 at least two working days before you dig. Marking is free. |
| Plumber Costa Mesa (us) | Leaks, clogs, backups, water heaters, gas lines and anything on your side of the meter or in your home's drains and lateral | (657) 669-4766, answered 24/7. 1045 Logan Ave A, Costa Mesa, CA 92626. |
Call the utility first when the problem is in the street, at the meter or involves gas; call a plumber first when the problem is inside your home or in its drain lines.
| What you see | Call first | Then |
|---|---|---|
| Water gushing from the street, sidewalk or parkway | Your water district (Mesa Water 949-631-1200, press 9 after hours, or IRWD) | A plumber only if the district says the leak is on your side |
| No water at all, and neighbors are out too | Your water district | Nothing, unless service returns to neighbors but not to you |
| No water at your house only | Check your main shutoff and meter, then call the district | A plumber if the district confirms water is reaching the meter |
| Burst pipe or leak inside the house | Shut off your main valve, then call a plumber | Your water district only if you cannot shut the water off |
| Sewage coming up in a tub, shower or floor drain | A plumber | CMSD if neighbors have the same problem or a street manhole is overflowing |
| Sewage overflowing from a manhole in the street | Costa Mesa Sanitary District, (949) 645-8400 | Keep people and pets away from the flow and storm drains |
| Gas smell indoors or out | Leave, then SoCalGas 1-800-427-2200 from a safe place | 911 if there is danger; a plumber for repairs once SoCalGas has made it safe |
| Brown, yellow or cloudy water | Run cold water a few minutes; if it stays, Mesa Water water quality 949-574-1031 | A plumber if only hot water is discolored (often the water heater) |
| High water bill with no visible leak | Read your meter with all fixtures off | A plumber for leak detection if the meter keeps moving |
| Planning to dig for a sprinkler, fence or sewer repair | 811, two working days ahead | A plumber or contractor once lines are marked |
| Downed power line near a water leak | 911, then SCE 1-800-611-1911 | Stay at least 100 feet away |
For anything that is clearly on your property, such as a leak under a sink, a water heater dumping water in the garage or a backed-up main line, you can call us at any hour. Our 24/7 emergency plumber page lists what to do in the first ten minutes while help is on the way.
The name on your water bill tells you which district serves you: Mesa Water District serves most of Costa Mesa, and IRWD serves parts of the city.
Mesa Water District serves about 110,000 people in most of Costa Mesa, part of Newport Beach and some unincorporated areas. Its office is at 1965 Placentia Avenue. The Irvine Ranch Water District says it serves parts of Newport Beach, Tustin, Costa Mesa, Orange and unincorporated Orange County. Neither district's documents that we read list exact Costa Mesa neighborhoods for IRWD, so we do not either.
Here are the reliable ways to find out:
The district's name and logo are on every bill. This is the fastest and most reliable check.
In many apartments and condos, water is billed to the owner or association. They will know the provider even if you never see a bill.
Home purchase disclosures and many leases name the water provider.
Call 949-631-1200 during business hours and ask whether your address is in their service area. If not, call IRWD at 949-453-5300.
Why it matters: the two districts have different emergency lines, different rates and different water. Mesa Water's 2026 report shows local groundwater at about 6.6 grains of hardness. IRWD blends local groundwater, surface water and imported water. Our Costa Mesa water hardness guide covers the numbers.
Sewer is simpler. The Costa Mesa Sanitary District, founded in 1944, collects sewage from about 118,000 residents in Costa Mesa, parts of Newport Beach and unincorporated Orange County, and sends it to OC San for treatment and recycling. So even if IRWD supplies your water, CMSD is very likely your sewer agency. If you are near the city edge, confirm it with CMSD.
As a working rule, problems in the street and at the meter go to the water district first, and problems on the house side of the meter go to a plumber.
Your water meter usually sits in a concrete box near the sidewalk or curb. The pipe from the public main to the meter is part of the district's system. The pipe from the meter to your house, plus everything inside, is your plumbing. Mesa Water's contact page does not spell out exactly where its responsibility ends for every property, so if a leak is near the meter box, call the district first and let them tell you whose side it is on. That call costs nothing and can save you a plumber visit.
EPA WaterSense says household leaks can waste more than 9,300 gallons of water a year, and suggests a simple meter test. Turn off every fixture and appliance that uses water. Read the meter, wait two hours without using any water, and read it again. If the number changed, water is going somewhere. Mesa Water bills by the unit, and one unit is 748 gallons, so a hidden leak adds up.
The same idea applies to sewer, but the boundary is less obvious. CMSD's sewer permit guide says the existing laterals in the street or alley are 6-inch clay pipe. A plumber works on the home's drains and lateral. We do not state who owns or maintains the part of the lateral under the street, because we have not confirmed it. Ask CMSD at (949) 645-8400 where its responsibility begins at your address. Our sewer lateral guide lists the questions to ask.
Renters should report plumbing problems to their landlord or property manager first, except in a true emergency such as flooding or a gas smell, while owners call the utility or a plumber directly.
This matters in Costa Mesa more than in most cities. The City's 2023 economic profile puts owner-occupied homes at 40.3% of housing units, which means about 60% of homes are rented. More than a third of the city's roughly 44,239 housing units, 35.4%, are in buildings with five or more units. In apartment buildings along Harbor Blvd, Newport Blvd and elsewhere, units often share water lines and sewer laterals, so one clog or leak can affect several households.
California Civil Code section 1941.1 says a rental is untenantable if it substantially lacks plumbing and gas facilities that met the law when installed and are maintained in good working order, or a water supply with hot and cold running water connected to an approved sewage system. In plain terms, working plumbing is part of what the landlord provides.
We work for landlords and property managers across Costa Mesa, from duplexes on the Eastside to larger apartment complexes. Our landlord and property manager plumbing page explains how we coordinate tenant access and send written reports.
If only your home is backing up, the problem is usually in your drains or lateral and you need a plumber; if a street manhole is overflowing or several neighbors back up at once, call the Costa Mesa Sanitary District.
A sewage backup is the call people are least sure about. Use these clues before you pick up the phone.
One drain or one bathroom backs up. Toilets gurgle when the washer drains. The cleanout in the yard is full but the street manhole is dry. Neighbors are fine. Call a plumber for drain cleaning or a main line clearing.
Sewage is coming out of a manhole in the street. Several homes on the block back up at the same time. Your cleanout drains slowly even after clearing. Call CMSD at (949) 645-8400.
Stop using water in the house as soon as you see a backup. Every flush and every load of laundry adds to the overflow. Keep children and pets away from sewage and do not try to clean up a large spill without gloves and ventilation.
Sewer overflows reach the ocean faster than people expect. On May 2, 2025, about 4,000 gallons spilled at East Mesa Verde Drive and Golf Course Drive after tree roots and cooking grease restricted the line. About 3,000 gallons were recovered, and the county temporarily closed ocean waters near the Talbert Channel. If you see sewage heading for a storm drain, report it right away.
If the camera shows roots, grease or broken clay in your own lateral, our sewer line camera and repair page covers the options.
Costa Mesa plumbing permits come from the City's Building Safety Division, sewer permits come from the Costa Mesa Sanitary District, and any digging starts with a call to 811.
City of Costa Mesa Building Safety is at 77 Fair Drive, 2nd floor. Applications and inspections run through the City's online system, TESSA, and simple limited-scope jobs may qualify for an Insta-Permit. The phone number is 714-754-5273. Our Costa Mesa plumbing permit guide covers the water heater standard and construction hours.
CMSD handles sewer permits through its own online portal. Its permit guide says reused laterals must be camera inspected and the video sent to CMSD, with any defects repaired.
Before anyone digs, whether for a sewer repair, a new gas line to a backyard kitchen or a sprinkler run, call 811. Southern California Edison notes that California law requires the call at least two working days before digging, not counting the day you call, and that marking is free. The marking is for utility lines. Lines you own, such as a gas line to a detached garage, may not be marked, so tell your plumber what you know about them. See our gas line plumber page for gas work.
Call us at (657) 669-4766 for anything on your side of the meter or in your home's drains, any hour of the day.
We are a local Costa Mesa plumbing service at 1045 Logan Ave A, Costa Mesa, CA 92626. Phones are answered 24/7. Work is done by independent CSLB-licensed C-36 plumbing contractors, you get a written price before work starts, and City permits are pulled when the job requires them. We will give you an honest arrival window, and if the problem turns out to belong to Mesa Water, IRWD or CMSD, we will tell you so you are not paying for something the utility handles.
A real person answers 24 hours a day. You get an honest arrival window and a written price before any work starts.
Call your water district. For Mesa Water, call 949-631-1200, and after hours press 9 to reach Costa Mesa Police or call 714-754-5251. IRWD customers call 949-453-5300.
Call 949-631-1200 and press 9, which transfers you to the Costa Mesa Police Department. You can also call the police line directly at 714-754-5251.
Check the name on your water bill. Renters can ask the landlord or HOA. You can also call Mesa Water at 949-631-1200 with your address and ask if you are in their service area.
Call a plumber if only your home is backing up. Call the Costa Mesa Sanitary District at (949) 645-8400 if a street manhole is overflowing or several neighbors back up at once.
Generally the property owner and their plumber handle pipes on the house side of the meter, and the district handles the main and meter. If a leak is near the meter box, call the district first and ask whose side it is on.
Leave the area right away and call SoCalGas at 1-800-427-2200 from a safe place. Call 911 if anyone could be hurt. Do not stay inside looking for the source.
Usually not. Report the problem to your landlord or property manager first, in writing. In an emergency, stop the damage by shutting off the water, then notify the landlord right away.
Yes. Call 811 at least two working days before you dig. Utility lines are marked for free. Lines you own on your property may not be marked, so tell your plumber about them.
The City of Costa Mesa Building Safety Division at 77 Fair Drive, 2nd floor, 714-754-5273. Sewer permits come from the Costa Mesa Sanitary District. See our permit guide.
Facts on this page come from these public sources, checked November 1, 2026.