A sudden jump in your water bill usually comes from a leak (most often a running toilet), seasonal use like lawn watering, or a billing change such as an estimated reading or a rate increase. Compare the bill's usage in gallons with past months, then do a meter test with all water off. If the meter moves, work through toilets, faucets, appliances, irrigation and finally hidden leaks.
A water bill that suddenly jumps is often the first sign of a leak, but not always. It can also be the sprinklers or a billing change. Work through these nine checks, easiest first, to find out which.
First: read the bill, not just the total
Look at the usage in gallons (or cubic feet) and compare it with the same month last year and the last few months. Also check:
- Was the reading actual or estimated? An estimated bill followed by an actual reading can make one month look huge.
- Did the rates change? A rate increase raises the total even when usage is the same.
- How many days does the bill cover? A longer billing period means a bigger bill.
If the gallons went up, keep going.
1. Do the water meter test
Turn off all water inside and out, note the meter reading and the leak indicator, and wait one to two hours. The U.S. EPA recommends a two-hour test (EPA WaterSense). If the meter moves, there’s a leak. The rest of this list helps you find it.
2. Check every toilet
A worn flapper or a fill valve set too high can let a toilet run silently all day. Put a few drops of food coloring in the tank and wait 10 minutes without flushing. Color in the bowl means a leak.
3. Look for dripping faucets and showerheads
A small drip adds up. The EPA notes that a faucet dripping once per second can waste more than 3,000 gallons a year.
4. Check the water heater
Look for water around the base, a discharge pipe from the relief valve that drips, or damp fittings. A water heater that runs more than usual can also point to a hot water leak elsewhere.
5. Check the water softener
A softener stuck in a regeneration cycle can send water to the drain for hours. Listen for water running to the drain when it shouldn’t be.
6. Check appliances and supply lines
Washing machine hoses, the dishwasher connection, the refrigerator’s ice-maker line, and supply lines under sinks.
7. Check outdoor spigots and hoses
A hose left connected to a spigot, or a frost-free spigot that cracked over the winter, can leak into the wall or the ground.
8. Check the sprinkler system
Irrigation is often a home’s biggest water use in summer. A broken head, a stuck valve, or a mainline leak can waste a lot of water. Close the irrigation isolation valve and repeat the meter test. See how to find a sprinkler leak.
9. Consider a hidden leak
If everything above checks out and the meter still moves with all water off, the leak is hidden:
- Under the slab. Look for warm spots on the floor. See how to find a slab leak.
- Inside a wall. Look for stains, bubbling paint or a musty smell. See how to find a leak in a wall.
- In the buried service line. Close the main shutoff. If the meter still moves, the leak is outside. See how to find an underground water leak.
Quick reference
| What you notice | Most likely cause |
|---|---|
| Bill jumped, gallons didn’t | Rate change, estimated reading or a longer billing period |
| Gallons up in summer only | Irrigation use or a sprinkler leak |
| Toilet refills on its own | Flapper or fill valve leak |
| Meter moves, nothing visible | Hidden leak: slab, wall or service line |
| Warm floor + high bill | Hot water slab leak |
Can you get a bill adjustment?
Many water utilities offer a one-time leak adjustment once a leak is repaired. Ask your utility about their policy and keep the repair receipt and any leak detection report.
When to call for leak detection
If the meter confirms a leak you can’t find, our hidden water leak detection service locates it without tearing up floors or walls. We serve Bargersville and the rest of Johnson County.
Still can’t find it?
Our hidden water leak detection pinpoints the leak without tearing things up, so the repair starts in the right spot.
Frequently asked questions
What is the most common cause of a high water bill?
A leaking toilet is one of the most common causes. A worn flapper can let water run from the tank to the bowl all day without being obvious. Irrigation use and billing changes are the other usual suspects.
How do I check if my high water bill is from a leak?
Turn off all water use and watch your water meter for one to two hours. If the reading changes or the leak indicator moves, you have a leak.
Can a hidden leak double my water bill?
It can. A leak that runs constantly adds up quickly. The EPA notes that about 1 in 10 homes has leaks wasting 90 gallons or more per day.
Should I call the water company about a high bill?
Yes, ask whether the reading was actual or estimated, and whether rates changed. Some utilities offer a leak adjustment if you fix a leak and show proof, so keep receipts and reports.