Why is my water bill so high?

Potential Causes of High-Water Bills

 An unusually high water bill is most often caused by a leak or change in water use. Some common causes of high water bills include:

  •  A leaking toilet or a toilet that continues to run after being flushed 
  • A dripping faucet: A faucet drip can waste 20 gallons of water a day or more
  • Filling or topping off a swimming pool
  • Watering the lawn, new grass, or trees; also check for an open hose bib
  • Kids home for summer vacations or school holidays; guests
  • Water-cooled air conditioners
  • A broken water pipe or obvious leak; check the pipes in the basement or crawlspace; the water heater could also be leaking
  • Water softener problems - cycles continuously
  • Running the water to avoid freezing water pipes during cold weather

Generally, water consumption is higher during the summer due to the watering of lawns, pools, and gardening. An average family of four typically uses 4,000-5,000 gallons of water a month. Here are a few things to check if you get a higher bill than usual. 

Changes in your water use

Did you have house guests, water your lawn more than usual, or do anything else out of the ordinary in the last month that uses a lot of water? If so, this may account for an increase in your water bill.

Check for leaks

Leaks can waste hundreds or even thousands of gallons of water, whether unseen or unfixed. It is important to routinely check your plumbing and home for leaky faucets, toilets, and outside taps and irrigation lines.

Toilet and faucet leaks

The most common cause for a high-water bill is running water from your toilet. A continuously running toilet can waste up to 200 gallons a day. That can double a family's typical water use, so fix toilet leaks as soon as possible. Some leaks, such as a dripping faucet or running toilet, are easy to find. You can usually hear a running toilet, but not always.  See the toilet assessment below for help in determining if this is the cause of your high-water bill.

Outdoor and underground leaks

Leaks can also occur in harder-to-find places, such as under your house or in the service line between your water meter and home. Check outdoor spigots and crawl spaces, and look for wet spots in your yard which may indicate a leak.


Do-It-Yourself Toilet Assessment

First, check for the most common leak: a deteriorated or defective flush valve (flapper) ball at the bottom of the toilet tank. Water will leak into the toilet bowl if it does not make a tight seal. To check for this:

  • Take the lid off the tank behind the bowl, flush the toilet, and wait for it to refill fully.
  • Put a few drops of dye or a colored dye tablet (available at some hardware stores) in the tank.
  • Wait at least 20 minutes; longer if you suspect it is a small leak.
  • If there is any color in the toilet bowl, there is a leak.

The second most common type of leak involves an improperly adjusted or broken fill (ballcock) valve. To check for this, take the lid off the toilet tank, flush it, and see if water drains into the overflow tubes when the tank is full.

The following table shows the amount of water that can be lost (and billed to your account) for various-size leaks.

Leak Size
Gallons Per Day
Gallons Per Month
Cubic Feet Per Quarter
A dripping leak consumes
15 gallons
450 gallons
180 cubic feet
A 1/3 in. leak consumes
264 gallons
7920 gallons
3168 cubic feet
A 1/16 in. leak consumes
943 gallons
28,300 gallons
11,319 cubic feet
A 1/8 in. leak consumes
3,806 gallons
114,200 gallons
45,681 cubic feet
A 1/4 in. leak consumes
15,226 gallons
456,800 gallons
182,721 cubic feet
A 1/2 in. leak consumes
60,900 gallons
1,827,00 gallons
730,800 cubic feet

Irrigation Systems

During the summer, irrigation systems are a common source of high-water use. Watering times generally double during the summer months compared to the winter. Automated irrigation systems should be checked regularly to be sure they are functioning properly and have no leaks or broken sprinkler heads. If a sprinkler valve sticks on, it could waste an extremely large quantity of water. The irrigation timer may not be programmed properly; i.e., sprinklers are watering too often and/or too long. Reprogramming may be necessary if the power has been off.

Water Softeners

Customers with water softeners have higher water bills due to the regeneration or backwash cycles their systems go through. The systems are preset to regenerate or backwash regularly. The systems will use water to clean the filter media and discharge the wastewater into the ground next to the system. Sometimes, these systems will get stuck in a cycle, which will cause higher water use.

What Can I Do if My Bill is Unusually High?

If you receive a bill, you feel is too high, check over the common causes listed above. This may help to pinpoint the source of the high bill. Most often, the City's utility billing program will detect unusually high bills, and the City will automatically send our utility staff out to check the meter and the property for a leak. If you feel your bill is too high and the city has not contacted you, call 919-775-8215. City staff will schedule for the meter reading to be rechecked. If the meter reading is checked and found to be accurate, you may need to contact a plumber or other professional to help determine the source of a leak. Property owners are responsible for all private service water lines from the public water main to the residence and leaks inside the home.

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