What Is a Water Meter and How Do You Use It to Find Leaks?
A water meter measures the volume of water entering a property, and it also marks the boundary of responsibility: the utility owns the line up to and including the meter, and the property owner owns everything after it. Because it records all flow, it is the most reliable free diagnostic tool available for detecting hidden leaks.
The meter test
This costs nothing, takes an hour of not using water, and identifies whether a leak exists anywhere in the system.
Stop all water use
Turn off every fixture and appliance, including ice makers, humidifiers, and irrigation.
Read the meter
Note the full reading, and check the low-flow indicator, usually a small triangle or star that spins with even tiny flow.
Wait an hour
Use no water at all during this period.
Read again
Any change, or any movement of the low-flow indicator, confirms water is leaving the system.
Narrow it down
Close the main shutoff and repeat. If the meter still moves, the leak is between the meter and the house rather than inside it.
Which side of the meter matters
A leak on the street side of the meter is generally the utility's responsibility and should not cost you anything. A leak between the meter and the house is yours, and can be an expensive excavation.
The refinement above, closing the main and seeing whether the meter still moves, distinguishes the two, and it is worth doing before paying for any detection or excavation.
Frequently asked questions
Where is my water meter?
Usually in a covered box at ground level near the street or property line, sometimes in a basement or utility area in colder climates where outdoor meters would freeze. Utilities can tell you, and many now provide online usage data that makes leak detection easier still.
Can I use online usage data instead?
If your utility provides hourly or daily usage data, yes, and it is often better than a manual test. A continuous baseline overnight, when nobody is using water, is a clear leak signature and shows roughly how long it has been happening.
See also
Related services
- Emergency Leak DetectionNon-invasive location of hidden water leaks behind walls, under floors, and beneath slabs using acoustic, thermal, and pressure testing equipment.
- Main Water Line RepairRepair and replacement of the buried water service line between the meter and the house, including trenchless replacement options.
- Slab Leak Detection and RepairLocation and repair of water lines leaking beneath a concrete foundation, using acoustic and thermal detection to minimize concrete work.