Quick answer
In the City of San Diego, single-family water is billed in tiers: $8.51 per HCF up to 10 HCF, $9.50 from 11 to 22 and $11.89 above 22, plus a base fee. A running toilet or hidden leak pushes use into the higher tiers. Turn off all water, watch the meter for 30 minutes, and request a leak adjustment within 120 days of the first high bill.
Updated · By the San Diego Plumber Pros editorial team · How we research
How is a City of San Diego water bill calculated?
The City of San Diego Public Utilities Department's water billing rates, effective January 1, 2026, charge a typical single-family home with a 3/4 inch meter a monthly base fee of $35.53 plus a price per unit of water. One unit, called an HCF, is 100 cubic feet or 748.05 gallons.
| Monthly use (single-family) | Price per HCF (from Jan. 1, 2026) |
|---|---|
| 0 to 10 HCF | $8.51 |
| 11 to 22 HCF | $9.50 |
| Above 22 HCF | $11.89 |
Because the higher tiers cost more per unit, a leak does not just add water to the bill, it adds the most expensive water. Homes in other parts of the county are served by other water agencies, such as Helix Water District, Otay Water District, Sweetwater Authority or the cities of Escondido and Oceanside, which set their own rates. Check the agency named on your bill.
Are San Diego's rates about to change?
Yes. The city's rate adjustments page says a court decision, Patz v. City of San Diego (2025), found the current tiered structure does not comply with Proposition 218. The city has proposed a unitary rate, the same price per unit regardless of how much you use, starting January 1, 2027, and set a public hearing for October 6, 2026. The page lists a proposed single-family volumetric rate of $11.09 per HCF and a proposed monthly service charge of $40.97 for 5/8 and 3/4 inch meters. Check that page for the adopted figures. Under a flat rate a leak no longer pushes you into a pricier tier, but every leaked gallon still costs money.
Why can a winter leak raise your sewer bill for a whole year?
On its billing page, the city explains that each single-family customer's flat sewer rate is based on water used during the previous winter. The city monitors use mainly from November through April, takes the lower of two billing cycles, and the resulting rate applies from the bill that includes July 1 for one year. A toilet that runs all winter can therefore lift your sewer charge for the following 12 months. The city notes the reverse too: conserving water in winter lowers next year's sewer rate.
What are the common causes of a high bill?
The city's billing page lists four:
- More use than usual. The most common reason, such as extra people in the home or more landscape watering.
- A meter misread. You can submit a photo of your meter for comparison or ask for an in-person read.
- A leak at the water meter. Saturated soil, standing water or flow at the meter box. Leaks on the owner's side of the meter are the owner's responsibility; leaks on the city side are repaired by a city crew.
- A leak on your property. Running toilets are a classic example, along with hose connections, faucets, appliances and irrigation timers.
EPA's Fix a Leak Week page puts the scale in perspective: the average household's leaks can waste more than 9,300 gallons a year, and nine percent of homes have leaks wasting 50 gallons or more per day. A worn toilet flapper can silently leak thousands of gallons a year, and EPA suggests replacing flappers at least every five years.
How do you test for a leak with your meter?
- Turn off every faucet and water-using appliance, inside and out, including irrigation.
- Find the meter, usually in a concrete box near the curb, and note the dial position. Use a tool, not your fingers, to lift the lid.
- Wait 30 minutes without using water. The city says that if the dials have not moved, the home is relatively watertight.
- If the dial moved, check toilets, hose connections, faucets and appliances such as dishwashers, washing machines, water heaters and refrigerators.
- If everything is off and the dial still turns, you may have a concealed leak in an underground pipe or under the slab. That is when leak detection by a plumbing professional makes sense.
Our leak detection guide explains how slab and underground leaks are found.
Can you get money back for a leak?
Sometimes. The city's leak adjustment page says adjustments are considered for a non-irrigation concealed pipe leak. Irrigation leaks, swimming pool leaks and plumbing fixture leaks such as toilets do not qualify. Requests must arrive within 120 days of the first high bill, and you need the date the leak was found, the repair date and a copy of the repair invoice or receipt. Keep the plumber's invoice and photos. Other water agencies have their own policies; Otay Water District, for example, offers a one-time adjustment for single residential accounts.
What should you do next?
If a concealed leak is likely, get it located and repaired by a licensed contractor and keep the paperwork for the adjustment request. Our hiring guide covers the CSLB license check, and the water-saving upgrades guide covers fixtures and rebates that keep the bill down afterwards.
How does this site fit in?
This site is an independent homeowner guide operated by SWKM GmbH. We are not a contractor, we hold no license and we do not perform plumbing work. If you want help, email us your city or ZIP, what is happening and a few photos. We reply by email with practical next steps and, where we know a licensed contractor for your area, an introduction. Run the license checks above on anyone you hire.
Frequently asked questions
How long should my water meter be still during a leak test?
The City of San Diego says to turn off all faucets and water-using appliances, note the meter dial, and wait 30 minutes. If the dials have not moved, the home is relatively watertight. If the dial moved, check toilets, hose connections, faucets and appliances first, then consider a concealed underground leak.
Does a running toilet qualify for a San Diego leak adjustment?
No. The City of San Diego only considers adjustments for non-irrigation concealed pipe leaks. Irrigation leaks, swimming pool leaks and leaks from plumbing fixtures such as toilets and faucets do not qualify. Requests must be received within 120 days of the first high bill and need proof of the repair.
Why did my sewer charge go up when my water use is normal now?
For City of San Diego single-family homes, the flat sewer rate is set from water used the previous winter, mainly November through April, and applies for a year starting with the bill that includes July 1. A leak or heavy use during that winter window carries into the next year's sewer charge.
Who fixes a leak at the water meter box?
It depends on which side of the meter the leak is on. The City of San Diego says leaks on the property owner's side are the owner's responsibility to repair, while leaks on the city side are repaired by a city crew. Report a suspected meter leak to the city's Water Emergency Hotline listed on its billing page.
Sources
Independent homeowner guide operated by SWKM GmbH. Not a licensed contractor. We do not perform plumbing work. More about this site.