The bill comes in and it is a good bit higher than last month. Nobody filled a pool. Nothing is dripping that you can see. So the question is whether the water company made a mistake or whether your house is leaking somewhere you cannot look.
Most of the time it is the second one. The good news is that you can narrow it down yourself in about two hours with no tools, in this order.
Start with the meter, not the house
Your water meter is the one honest witness. It counts every gallon that passes into the property, whether it goes to a faucet or into the dirt under your foundation.
The test the EPA’s WaterSense program recommends is simple: read the meter, make sure nothing in the house is using water for two hours (no washing machine, no ice maker, no irrigation), then read it again. If the number moved at all, water went somewhere. That is a leak.
The meter is usually in a box near the curb with a lid you can lift by hand. Older meters have a small triangle or star on the dial that spins when water is moving. If it is turning while every tap in the house is off, you do not need to wait the two hours.
For scale, the EPA’s rule of thumb is that a family of four using more than 12,000 gallons in a month, checked in winter when nobody is watering, may have a serious leak somewhere. Your bill shows your monthly usage, so it is a quick comparison.
The toilet test, because it is usually the toilet
The EPA lists worn toilet flappers among the most common household leaks, alongside dripping faucets and leaking valves. A flapper is the rubber seal at the bottom of the tank. When it wears, water seeps from the tank into the bowl around the clock, the fill valve tops the tank back up, and the whole thing is silent. You just pay for it.
The check takes ten minutes. Put a few drops of food coloring in the tank (not the bowl), do not flush, and come back. If color has shown up in the bowl, that toilet is leaking. Do this on every toilet in the house, because a house with one worn flapper often has two.
A flapper is a quick swap. If the toilet test finds the culprit, you may be done.
Walk the outside before you worry about the inside
If the toilets pass, go outside.
Irrigation. September is still full watering season around here, and an irrigation system is a lot of pipe, all of it underground, all of it under pressure whenever the system runs. Look for a patch of lawn that is greener or softer than the rest, a spot that stays soggy days after the last cycle, or a sprinkler head that bubbles instead of sprays. If your irrigation has its own shutoff, close it and repeat the meter test. If the meter stops, the leak is in the yard.
The line from the meter to the house. Follow the most direct path from the meter box to where water enters the house. A wet strip of ground along that path in dry weather, or a spot where the grass stands out in a drought, points at the service line. This is the same line we cover under yard and underground work on our services page.
Hose bibs and outdoor faucets. Easy to miss. A hose left connected with a leaky spray nozzle can run all week.
Signs the leak is under the slab
This is the one people are actually worried about. A slab leak is a leak in a water line that runs beneath the concrete foundation. Because it is under the house, you rarely see water. You see the effects.
- A warm spot on the floor. If the hot line is leaking, the concrete above it warms up. On tile you can sometimes find it barefoot.
- The water heater runs constantly, or the hot water never seems to fully recover, with no other explanation. A hot-side slab leak is a hot water tap that never shuts off. If the heater itself is acting up, our repair-or-replace guide covers what is a part and what is the tank.
- The sound of running water when nothing is on. Put your ear to a wall near the bathrooms or kitchen at night.
- Low water pressure that came on gradually, with no work done on the plumbing.
- Moisture at the base of a wall or a cabinet, mildew smell in a closet, or flooring that lifts, cups, or discolors near an interior wall.
- Hairline cracks in the slab or in walls that appeared recently. Not every crack is a leak, but one that shows up alongside two or three of the signs above deserves a look.
One more meter trick that helps here: shut off the main valve at the house (not at the meter) and check the meter again. If the meter keeps moving with the house valve closed, the leak is between the meter and the house, in the yard. If it stops, the leak is inside the house or under it.
What to do the day you confirm it
If you find the source and it is small, like a flapper or a hose bib, fix it and re-run the meter test.
If the meter moves and you cannot find why, that is the point to call rather than start pulling up floors. A leak that cannot be seen is located with equipment, not with a shovel: listening gear that picks up the sound of pressurized water escaping, thermal imaging that shows the warm line, and pressure isolation that tells us which line is losing and which is holding.
Turn the water off at the house valve when you are away if the leak is confirmed and the repair is a day or two out. It stops the meter, and it stops the damage.
How we handle a hidden leak
We locate first. You get the location and a flat quote in writing before anything is opened, and the quote is the number you pay. On a slab leak, rerouting the line is our first option rather than cutting the foundation, because it leaves the slab alone. Every job comes with insurance-ready documentation, because a confirmed leak is often a claim.
If your bill jumped and the meter will not hold still, call (281) 786-3695. Tell us what the meter did with the house valve open and closed. That one detail puts us a step ahead before the truck leaves.