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Why Was My Water Bill High

For questions about your Water Utility Bill or to set up service, please contact Utility Billing at 425-587-3150.

Have you received a water bill that seems unusually high?  Your water bill could be higher than normal for a number of reasons.  Here are some ways you can troubleshoot to see why your bill is high:

  1. Your bill includes a graph of your water consumption (in units where 1 unit = 748 gallons of water) for the past 12 months.  Does the consumption seem normal compared to the previous billing period or the same billing period last year?
  2. Has the amount of water you've been using changed?  Have you had houseguests for an extended period of time?  On average, a person uses 40-80 gallons of water per day.  See How Much Water Do I Use Daily for more details.
  3. During the summer months, watering your lawn more frequently is the most common reason a bill can be high.  Running your sprinkler for just one hour can use 400 gallons of water.  If you use a hose to water, did you forget to go back out and turn it off?
  4. There could be a leaking faucet or a running toilet in your home.  Check for a possible leak by turning off everything in the house and then going out and looking at the water meter.  It should not be moving at all.  If it is moving, you have a leak somewhere in your house.

    See It's Only a Small Drip...Right? for more information on checking for common water leaks. 

    See How Much Water is Lost? to find out how small leaks can lead to big trouble.
  5. Did you fill a swimming pool with a garden hose?  Or maybe use a pressure washer to clean the deck and driveway? At four gallons per minute, pressure washing for four hours can use 960 gallons or over a unit of water. 

How Much Water Do I Use Daily?

On average, a person uses about 40 to 80 gallons of water per day (gpd):

Use Average / Person (gpd)
Bathing 15-25
Sink 3-5
Toilet 5-15
Washing Clothes 10-20
Washing Dishes 5-10
Cooking 1-2
Miscellaneous 1-3
Total 40-80

It's Only a Small Drip...Right?
Slow drips of water can add up quickly.  A toilet that “keeps running” after you flush or a sink that drips after it is turned off can waste thousands of gallons of water a year.  A small leak in your automatic irrigation system can waste about 6,300 gallons of water per month!  If the drip is hot water, you are paying for wasted energy too.  Fix leaks as soon as you find them.  They won’t go away on their own.

A “Running” Toilet Leak

One of the most costly household wastes of water is a leaky toilet. According to the American Water Works Association, toilets account for 45% of all indoor water use in a typical residence. It is estimated that 20% of all toilets leak!

Toilet leaks can range from small to large, constant to random, or from being heard or silent. They all cause wasted water. Depending on the water pressure to your house, a running toilet can leak over 1 gallon of water per hour which adds up to 26 gallons per day. This is almost 1 unit of water a month and if left undiscovered, a running toilet can waste almost 13 units of water a year.

Fortunately, most toilet leaks are relatively easy to fix. In a properly functioning toilet, no water should move from the tank to the bowl, unless the toilet is being flushed. A leaking toilet loses water from the tank to the bowl without being flushed (#1 below). A toilet can also waste water due to an improperly adjusted or broken fill (ballcock) valve causing water to enter the tank and flow into the overflow tube (#2 below).

  1. Most toilet leaks are caused by a faulty valve (also known as “flush valve ball” or “tank stopper”). A flapper valve should be replaced every 3 to 5 years. Most hardware, plumbing and home improvement stores supply flappers. How to check for a leaky toilet flush valve (flapper):

    - Carefully remove and set aside the tank lid. (Don’t worry, this water is clean until it enters the bowl.)
    - Add some food coloring or a dye tablet to turn the water a different color.
    - Put the tank lid back on.
    - Wait 15 minutes and do not flush.
    - If dye appears in the toilet bowl, the flapper valve in your toilet is leaking and should be replaced.
  2. The second most-common type of toilet leak is caused by an improperly adjusted or broken fill (ball cock) valve. If the float is set too high or if the shut-off valve fails to close completely, water will continue to enter the tank and flow into the overflow tube.

    This type of leak can be seen simply by taking the tank top off and observing if water is flowing into the overflow tube once the tank is full.

If you do need to replace the entire toilet, look for a WaterSense labeled model. Visit for details regarding rebates on the purchase of a new WaterSense toilet.

A Leaking Faucet

A leaking faucet is frequently the result of a bad rubber washer. The washer on a sink is typically located under the handle. A washer is relatively easy to replace with the right tools. It does require shutting off the water under the sink, and removing the handle. Check local home centers or the Internet (keywords “repairing leaky faucets”) for help on how to repair faucet leaks.

A leaky faucet that drips at the rate of one drip per second can use more than 3,000 gallons per year!

A showerhead leaking at 10 drips per minute can use more than 500 gallons of water per year.

Use the WaterWiser Drip Calculator to Measure and Estimate Water Wasted

Leaky Automatic (in-ground) Irrigation Systems and Spigots

An irrigation system should be checked each spring before use to make sure it was not damaged by frost or freezing. An irrigation system with pressure set at 60 pounds per square inch that has a leak 1/32nd of an inch in diameter (about the thickness of a dime) can waste about 6,300 gallons of water per month!

To ensure that your in-ground irrigation system is not leaking water, consult with a WaterSense irrigation partner who has passed a certification program focused on water efficiency; look for a WaterSense irrigation partnerexternal link icon.

Check your garden hose for leaks at its connection to the spigot. If it leaks while you run your hose, replace the nylon or rubber hose washer and ensure a tight connection to the spigot using pipe tape and a wrench.

How Much Water Is Lost?

Small household leaks left unrepaired can lead to big trouble over time.
Leak Source Typical Leakage Gallons/ Day Used Gallons/Month Used Units/Month Used
 Running Toilet  1 gallon/hour  26  780  1
 Leaking Faucet  1 drip/second  9  259  0.3
 Leaking Showerhead  10 drips/minute  1.4  43  0.05
 In-ground irrigation  1/32” in diameter (about the thickness of a dime)  210  6,300  8
 A garden hose left running or a missing sprinkler head  ½” in diameter  4,320  129,600  173

Water is billed in units where 1 unit = 748 gallons of water.

Public Works
123 5th Avenue, Kirkland WA 98033
T. 425-587-3800 | F. 425-587-3807
Mon-Fri, 8 a.m. to 5 p.m.

Operations & Maintenance
915 8th St, Kirkland WA 98033
T. 425-587-3900 24/7 | F. 425-587-3902
Mon-Fri, 6:30 a.m.-3:30 p.m.

General Inquiries - Contact us via the: 
Our Kirkland Customer Service Portal