How to Read Your Water Meter and Find a Leak
Your meter is a free leak detector. Two simple tests tell you whether water is running when nothing should be using it.
- 24/7 emergency calls
- Nights, weekends and holidays
- Mission Viejo, CA
Where the Meter Is and What It Shows
Three water districts supply Mission Viejo, according to the City of Mission Viejo. They are Santa Margarita Water District, Moulton Niguel Water District and El Toro Water District. Your bill names yours, and meters differ a little by district, so use the picture on your own bill as the guide.
Most residential meters sit in a ground-level box near the curb or the property line. The lid may be heavy and may hide insects, so lift it with a screwdriver or a meter key and keep your hands clear. Do not reach into the box without looking first.
Under the lid is a dial with numbers and a sweep hand. One district describes it this way: one cubic foot of water passes through the meter as the sweep hand moves from one number to the next, and a full rotation is 10 cubic feet. Check your own meter's units, because some read in gallons.
The Ten Minute Test
Turn off everything
Stop all water use. That includes the dishwasher, the washing machine, the ice maker, irrigation and any running tap.
Find the leak indicator
It is usually a small triangle or a star-shaped wheel on the dial that turns when any water moves through.
Watch for ten minutes
If the indicator or the sweep hand moves, water is flowing somewhere. A meter that does not move means no continuous leak right now.
A moving meter tells you there is a leak. It does not tell you where.
The Slow Leak Test
A very small leak may not move the sweep hand in ten minutes. The district guide recommends a second test. Record the meter reading, wait 20 minutes with all water off and record it again. Subtract the first from the second, and if the result is greater than zero you have a continuous leak.
The EPA suggests a longer version. Check the meter before and after a two-hour period when no water is used, and if the reading changes there is probably a leak. EPA WaterSense also reports that nine percent of homes have leaks that waste 50 gallons or more per day.
Run the test when the house is quiet, such as after everyone is asleep. Do not flush a toilet or run a faucet during the wait, because even one flush will give a false reading.
Where the Leak Is: Inside or Outside
Once you know water is moving, find out which side of the house valve it is on. Close the main shutoff valve at the house and watch the meter again. If the meter stops, the leak is inside the house. If it keeps moving, the leak is on the buried line between the meter and the house, or at the meter.
| Result | Where the leak is | Next step |
|---|---|---|
| Meter moves, stops after house valve closes | Inside the house | Check toilets and fixtures, then hidden lines |
| Meter moves with house valve closed | Buried line or at the meter | Check the lawn and call about the water line |
| Meter stops with all water off | No continuous leak now | Check the bill and irrigation timers |
| Meter moves only when irrigation is on | Irrigation system | Check valves and sprinkler heads |
For a leak on the buried line, see water line repair and replacement. A leak at the meter itself is the district's to fix, so call the district.
Common Culprits Inside the House
Toilets are the most common source. EPA WaterSense says household leaks can waste 180 gallons per week and toilets are often the culprit. Drop some food coloring into the tank, then leave the toilet unflushed for about 15 minutes. Color in the bowl means the flapper is leaking.
A flapper is an inexpensive part. Toilet repair and replacement explains when to fix it and when to replace the toilet.
Next check the faucets and the shutoff valves under each sink. A single drip adds up over a day. If the fixtures are dry and the meter still moves, the leak is probably in a wall or under the floor. A visit for leak detection finds it without opening every wall.
A warm spot on the floor or the sound of running water points to a line under the slab. Read slab leak repair for what that involves.
Keep a Simple Log
Write down the meter reading on the first of each month. It takes ten seconds and gives you a trend you can compare with your bill. A reading that climbs faster than usual with no change in habits is a reason to run the tests above.
The log is also useful if a leak is later found. It shows roughly when the extra water began, which matters for a bill adjustment request and for an insurance conversation.
When to Call a Plumber
- The meter moves with every fixture off and you cannot find the source.
- A wet or sunken patch appears in the lawn with no irrigation running.
- Water pressure drops with no clear cause.
- Your bill climbs with no change in habits.
- You find water at the meter or in the meter box.
Meter moving with everything off?
Close the main valve and call. Say what the test showed and the plumber will tell you what to check next.
Sources and Standards
Local figures and standards on this page come from these published sources.
Common Questions
Turn off all water, then watch the leak indicator or the sweep hand for ten minutes. If either moves, water is flowing.
It is usually a small triangle or star that turns when any water passes through the meter, even a slow flow.
It varies. Many read in cubic feet, and one cubic foot is about 7.5 gallons. Check your district's guide.
Then the leak is inside the house. If it keeps moving, the leak is on the buried line or at the meter.
Partly. A leaking toilet can move the meter slowly. The food coloring test in the tank is a quick way to confirm.
Found a Leak? Call Now
Call any hour in Mission Viejo. Share the meter test results and the plumber will help you find where the water is going.
Call (949) 998-2846