Testing for Leaks

Leaky Faucet

Drips and leaks allow water and your money to go down the drain. Just a slow drip can use up to 15 to 20 gallons a day, while a toilet that keeps running can waste thousands of gallons of water a year. Leaks are estimated to waste more than 10% of indoor water supply, driving up water and sewer costs. Conserve water and save money by finding and fixing leaks.

Although most leaks can be heard or seen, many homes have hidden leaks that are easily overlooked.

Learning if you have a leak

Finding a water leak with your meter.

Turn off of all water-using appliances and fixtures inside and outside your home. Use no water during the test period.

Locate you water meter at the front of your property (usually in a concrete box). Look for the white stripe on the curb that our meter readers use to find your meter.

Use the water meter diagram to see if you have a leak.

Most meter faces have a flow indicator. If there is no water being used at the time of inspection, and the flow indicator is spinning, there may be a leak somewhere in or around your home. Not all leaks are big and clearly noticeable. If the flow indicator is not moving, continue with these steps to further evaluate the situation:

  1. Write down the numbers on the meter's register. Wait 30 minutes without using any water inside or outside your home. Then take another reading from your meter's register. Compare it to the first reading. If the second reading is higher, there may be a leak.
  2. To pinpoint whether the leak is coming from inside or outside the home, close the house shut off valve (generally located on an outside wall where the water line enters the home, or near the water heater).
  3. Repeat Step 1. If the meter continues to move, the leak may be outside the home in the service line that leads from the meter to the home, or in any water-using device that may be hooked to the system outside the home.
  4. If the meter does not move after your second test, the leak may be inside the home.

Common Culprits

Leaking toilets or dripping faucets are the usual sources of leaks. A leaky toilet loses water from the tank into the bowl without being flushed. Many of these leaks are silent. To test for toilet leaks:

  • Lift the lid off the toilet tank and put five to 10 drops of food coloring into the tank.
  • Wait five minutes, then look in the bowl. If you see food coloring in the bowl, you have a leak.

In most cases, replacing the toilet flapper and/or the filling mechanism will correct the problem.

A leaky faucet is often the result of a bad rubber washer. The washer is typically located under the handle and can be easy to repair, if you have the right tools. Check the Internet for instructions on how to repair leaks. Many local home centers also offer good advice. If in doubt about any repair, seek a plumbing professional.

For help in determining if you have a leak, call Bellevue Utilities at 425-452-6973.

Leaks outside your home

The city maintains all water mains and service lines in the public right of way or city-owned easements. The homeowner is responsible for their private line that runs from the water meter to the home. Pooling water in areas of your landscape or a wet spot that never dries on concrete may be signs of a leak in that line. 

You should call a plumber to determine whether there is a leak and fix it if necessary. To prevent potentially severe damage to your property from a leak, you may want to shut off your water at the meter

If you see water bubbling up or gushing from the street, the water main underneath may be broken. please contact the city’s 24-hour emergency line immediately at 425-452-7840. The city relies on reports from our residents to help us identify and fix small leaks before they become large breaks. Some areas have high amounts of naturally occurring groundwater. If necessary, the city can test the water to determine if it is drinking water or groundwater.