Start with the bill itself
Look at the usage number, not just the total. Compare it with the same months from a year ago. A change in the rate or the fees is a billing matter. A change in the gallons used means water physically went through the meter.
Then ask what changed at home. Guests, a new appliance, a garden hose left running or a pool fill can account for a jump. If nothing changed, a leak is the next suspect.
The two-hour meter test
Turn off everything
Shut off every fixture and appliance that uses water. Make sure the ice maker and the washing machine are idle.
Read the meter
Note the number on the dial, and any small leak indicator that spins.
Wait two hours
Use no water at all.
Read again
If the reading changed, water is probably leaking somewhere.
The EPA describes this as the way to confirm a household leak. If the reading did not change, the usage came from somewhere you can account for, and the bill may need to be discussed with the water supplier.
What household leaks usually cost
The EPA says the average household loses more than 9,300 gallons a year to leaks, and that about nine percent of homes leak 50 gallons a day or more. That is enough to show up on a bill.
A toilet that runs on its own, for example, can waste a surprising amount of water without any noise. It is the first place to check.
Toilets first
| Test | What it shows |
|---|---|
| Put a few drops of food coloring in the tank and wait without flushing | Color in the bowl means the flapper leaks |
| Listen for a hiss or watch for ripples in the bowl | A fill valve or flapper is leaking |
| Press the flapper down gently | If the running stops, the flapper is worn |
A worn flapper is an inexpensive part. See toilet repair for the usual fixes. If the toilet is old, replacing it with a WaterSense model may save water too.
Outdoor and buried lines
Close the main shutoff at the house and watch the meter. If it still moves, the leak is on the buried line between the meter and the house, or at the meter itself. Look for wet or unusually green patches in the yard, soft ground or a spot that stays damp in dry weather.
Hose bibs, irrigation systems and underground lines all leak without a visible sign. See water line repair for how a buried line is checked.
Reading a meter
Most household meters have a dial or a digital register that shows total usage. They count in cubic feet or in gallons, and the unit is printed on the meter. A small triangle or star on the face spins when any water is flowing, even at a trickle. That is the leak indicator.
If the leak indicator is spinning with every fixture off, there is a leak. Take a photograph of the register and the time so you have a record. That makes a call with the water supplier or a plumber much simpler.
Seasonal and one-time explanations
- Filling a pool or watering a new lawn can add thousands of gallons in a week.
- A house with guests uses noticeably more than usual.
- A bill that covers more days than usual shows higher usage.
- An estimated read followed by an actual read can produce a catch-up bill.
- A faulty meter is rare but possible.
If none of these apply and the meter test shows water moving, treat it as a leak. If the meter test shows nothing and the bill is still high, the reading itself may be wrong, and the water supplier can test the meter.
After you find the leak
Fix the source first. A toilet flapper is a small job. A buried line is bigger. If the leak was running for weeks, check the area around it for damp materials, since wet wood and drywall can grow mold if they stay wet.
Take a reading of the meter after the repair and again after two hours to confirm the leak is gone. Keep the plumber's invoice. It is the document the water supplier is most likely to ask for.
How small drips add up
Small leaks are quiet and still expensive. The EPA says a faucet dripping once a second can waste more than 3,000 gallons a year and a showerhead leaking 10 drips a minute wastes more than 500 gallons. A worn toilet flapper can silently leak thousands of gallons.
None of these makes much noise, which is why the bill is often the first sign. Check the quiet fixtures before assuming the leak is buried.
Talking to the water supplier
- Ask for your usage history, not just the amount owed.
- Ask whether the meter was read or estimated.
- Ask whether a meter test is available if you think the reading is wrong.
- Ask whether any leak adjustment applies once you repair the leak.
- Keep the plumber's invoice and the date of the repair.
Policies differ from one water supplier to the next. Asking costs nothing, and a documented repair is often what the supplier wants to see.