An unexpectedly high water bill is frustrating, but it is also useful information: it tells you water is being used or lost at a rate that does not match your habits. Before you assume the worst, work through these checks in order. Each one takes a few minutes and narrows down the cause.
What should I check first when my water bill spikes?
Start with what changed. Think back over the billing period your utility just charged you for. Did you have guests staying over? Fill or top off a pool? Run sprinklers more because of a dry spell? Add a new appliance? Any of these can explain a jump honestly.
If nothing changed, pull out your last three or four bills and compare usage in gallons, not just dollars. Rates and fees can shift, so gallons tell the true story. Two or more high months in a row means real water loss.
How do I check my water meter for a hidden leak?
The meter is the single fastest way to find out whether water is escaping your plumbing system. Here is the basic version; the full step-by-step is in our water meter check guide.
- Make sure no water is being used anywhere: faucets off, dishwasher and washer off, ice maker and irrigation off.
- Find your meter, usually in a ground box near the street or sidewalk.
- Look for the leak indicator, a small triangle or star that spins with even tiny flows.
- If it is spinning, water is moving through the meter with nothing running. That means a leak somewhere.
If the indicator is still, do the two-hour test: record the meter reading, avoid using any water for two hours, then read it again. A higher number confirms a slow leak.
Could a toilet be the cause of my high bill?
Toilets are the most common cause of mystery water loss, and a running toilet can waste hundreds of gallons a day silently. Check every toilet in the house.
- Listen for water running or refilling when the toilet has not been flushed recently.
- Put a few drops of food coloring in the tank and wait 20 minutes without flushing. If color appears in the bowl, the flapper is leaking.
A flapper leak is cheap and easy to fix, and it resolves a huge share of high-bill mysteries. Check all toilets, including rarely used ones in guest bathrooms.
Could my irrigation system be running too much or leaking?
In Flower Mound, irrigation is a frequent culprit behind high summer bills. A sprinkler zone stuck on, a broken head gushing water, or a controller that lost its programming after a power outage can all use far more water than you realize.
Walk your yard while each zone runs and look for heads spraying into the street instead of the lawn, water bubbling up from the ground in one spot, or soggy areas and greener-than-normal patches of grass. Also check the controller itself: after power flickers, some controllers revert to default schedules that water daily.
What about my water softener or reverse osmosis system?
Water treatment equipment uses water to regenerate or flush, and a malfunctioning unit can send water down the drain continuously. If your softener's regeneration cycle is stuck, or an RO system has a failed valve, you can lose hundreds of gallons a day without a drop appearing anywhere visible.
Listen near the softener for running water when it should be idle, and check the discharge hose for a steady trickle that never stops. This kind of loss shows up at the meter just like a pipe leak does.
How do I know if the leak is under my slab or in my service line?
If the meter shows water moving with everything off, and you have ruled out toilets, irrigation, and treatment equipment, the leak is in the plumbing itself. The two most likely hidden locations are:
- The service line between the meter and your house. Signs include a soggy or sunken patch in the yard, water pooling near the foundation, or the sound of water near the main shutoff when everything is off.
- A slab leak in lines under the foundation. Signs include warm spots on floors, the sound of running water through the floor, new cracks, or musty smells. See our full slab leak signs guide for the complete list.
You can also do a simple isolation check: shut off the main valve where water enters the house. If the meter stops, the leak is inside your home's plumbing (possibly the slab). If the meter keeps moving, the leak is in the service line between the meter and the house.
What information should I gather before calling a professional?
Before you schedule a detection visit, pull together these details. They help the specialist find the leak faster:
- Your last two bills showing the usage jump
- Results of the meter test (indicator spinning, or the before-and-after readings)
- Which fixtures and systems you already checked and ruled out
- Any slab leak signs you have noticed: warm floors, sounds, cracks, odors
When is a high bill an emergency?
Call for emergency leak detection if the meter is spinning fast, you hear water rushing through walls or floors, water is pooling in the yard or seeping up through flooring, or the bill increase is dramatic and sudden. Fast-moving water causes fast-moving damage, and finding the leak quickly limits both.
A slow, steady increase with a barely-moving meter indicator is still worth addressing, but it can usually wait for a scheduled visit. Either way, do not let a confirmed leak run for weeks: prolonged moisture invites mold and soil problems under the foundation.