Guides · Twin Cities homes
Why is my water bill suddenly so high?
The short answer
A sudden jump in the water bill nearly always means a leak, and the most common one is a running toilet, which can waste hundreds of gallons a day without a sound. Check it in two minutes: with every fixture off, watch the water meter — if the small dial or the digits are moving, something is leaking.
The two-minute meter test
Make sure nothing in the house is using water — no dishwasher, no softener regenerating, no irrigation. Find the meter (basement, street side, where the line comes in) and watch it. Most meters have a small low-flow indicator — a little triangle or dial — that spins with even a trickle; digital meters show flow directly. If it's moving with everything off, you have a leak. Note the reading, wait an hour without using water, and read it again; the difference is the leak rate. Ten gallons an hour is 240 a day, which explains a lot of bills.
The usual suspects, in order
- A running toilet. A worn flapper lets water seep from the tank to the bowl continuously. Drop a few drops of food coloring in the tank; if color shows in the bowl within 15 minutes without flushing, that's it. See our running-toilet guide.
- A softener stuck in regeneration. A control valve that jams mid-cycle can run water to the drain for days. Listen at the softener drain line; it shouldn't be running outside a scheduled regeneration.
- Irrigation. A cracked lawn-sprinkler line or a zone valve stuck open can run underground for a whole season. Many Twin Cities cities bill sewer on winter water use for exactly this reason.
- A dripping faucet or outdoor spigot. Smaller, but a steady drip is thousands of gallons a year.
- An underground service line leak between the street and the house. Rare, but if the meter moves with the main shutoff closed on the house side, the leak is before the valve.
If it's not a leak
Sometimes the bill is real: a new high-use appliance, house guests, a leaky irrigation season, or a city rate change — several metro cities moved to tiered rates that punish high summer use. Compare gallons on the bill, not dollars. And check the meter reading against the bill; estimated reads happen, and a true-up after a long estimate can look like a leak that isn't there.
Try it yourself, or call?
Worth trying first
- The meter test above — it settles the question in two minutes
- Food coloring in every toilet tank
- Walk the yard for soggy spots or unusually green stripes over the irrigation or service line
Time to call
- The meter moves and you can't find where — we track it down in one visit
- The toilet test is positive and a new flapper didn't fix it
- The softener is running water constantly
- The meter moves even with the house-side main closed — that's the service line, and it's urgent
Common questions
How much water does a running toilet actually waste?
A moderate flapper leak runs 200 gallons a day or more; a fill valve that never shuts off can double that. Over a quarterly billing cycle, that's tens of thousands of gallons — often the entire explanation for the bill.
The city says my usage doubled but nothing changed. Could the meter be wrong?
Meters occasionally fail, but they almost always fail slow, not fast — a bad meter under-reads. Do the leak test first. If it's clean and usage is still doubled, ask the city to test the meter; most will.
Will the city adjust my bill for a leak?
Many Twin Cities utilities offer a one-time leak adjustment if you show the leak was repaired. Keep our invoice; it's usually the documentation they ask for.