Why Is My Water Bill Suddenly High? How to Check for a Leak

The short answer

A water bill that jumps for no obvious reason usually comes down to one of three things: the household used more water, the bill itself changed, or water is leaking somewhere you cannot see. You can sort out which one in an afternoon.

Turn off every faucet and water-using appliance, read your water meter, use no water for two hours, and read it again. The EPA says that if the reading changed at all, you probably have a leak (EPA WaterSense). Then put a few drops of food coloring in each toilet tank and wait 10 minutes; color in the bowl means that toilet is leaking (EPA WaterSense).

If the meter stays still and the toilets pass, the answer is more likely on the bill or in your household’s habits than in the pipes. If the meter moves with everything off, something is using water, and it is worth finding.

First, rule out the bill itself

Before you look for a leak, look at the bill. A few things raise a bill without anything being wrong with your plumbing:

• A catch-up after an estimated read. Artesian Water says it estimates a bill “in certain limited circumstances, such as when the meter is inaccessible or obstructed” (Artesian Water). If an earlier bill was estimated low, the next actual read can carry the difference. Check whether either bill is marked as estimated.
• A longer billing period. Compare the number of days and the gallons used, not just the dollar total.
• A rate or charge change. Your water provider sets rates and fees. Spangler cannot change those, and a plumber is not the right call for a billing dispute.

Bring rate, meter-accuracy, and billing questions to the provider named on your bill. Artesian, for example, says that if you are certain a leak is not the problem, you may request a meter test (Artesian Water).

Did the household just use more water?

Compare the gallons on this bill with the same period last year, if your bill shows it. Then think back over the billing period:

• Guests staying over, or a family member home more than usual
• Filling a pool or hot tub, washing cars, or watering a new lawn or garden
• An irrigation system running on a schedule nobody checked
• A new appliance, or more laundry than normal
• A hose left trickling outside

For a rough benchmark, the EPA notes that if a family of four uses more than 12,000 gallons a month in winter, there could be serious leaks (EPA WaterSense). Winter is the cleanest comparison because outdoor watering is usually off.

How to check for a leak with your water meter

This is the most useful check a homeowner can do, and it needs no tools.

1. Find the meter. In many homes it is in the basement or utility area where the water line enters. In others it sits in a pit near the curb under a metal or plastic lid. If the meter is in a pit with a heavy, stuck, or damaged lid, leave it alone and ask your water provider for help reading it.
2. Turn off all water use. Every faucet, shower, and toilet; the washing machine and dishwasher; the ice maker; irrigation; and a water softener if one is set to run.
3. Read the meter and write the number down. Take a phone photo of the dial.
4. Use no water for two hours. Leave the house or plan around it.
5. Read it again. If the number changed at all, the EPA says you probably have a leak (EPA WaterSense).

Many meters also have a small leak indicator. On Artesian meters, it is the red, star-shaped dial on the register. Artesian says it turns when water is running in the property and “should remain stationary” when all water is off (Artesian Water). If it is spinning while everything in the house is off, water is going somewhere.

What this check does not tell you. A moving meter says water is passing through it. It does not say where. The leak could be a toilet, a dripping fixture, a water heater, a line under a slab, a buried line in the yard, or something you forgot to turn off. A still meter over two hours also does not rule out a leak that only runs sometimes, like a toilet that refills every so often.

Check every toilet

Toilets are one of the most common silent leaks, because the water runs straight into the bowl and down the drain where you never see it.

• Do the dye test. Put a few drops of food coloring or a dye tablet into the tank, not the bowl. Do not flush. Wait 10 minutes. If color shows up in the bowl, that toilet is leaking (EPA WaterSense).
• Listen and look. A toilet that refills on its own, hisses, or runs after flushing is wasting water. The EPA says water flowing continuously into the overflow tube inside the tank is another sign to investigate or call a plumber.
• Check the base. The Delaware Department of Insurance notes that “a telltale sign of toilet seal leaks is water that gathers around the base” (Delaware Department of Insurance). That kind of leak can damage the floor, even if it does not show on the bill.

A worn flapper is a common cause of a dye-test failure. The EPA recommends replacing flappers at least once every five years (EPA WaterSense).

Look at everything else that uses water

Walk the house with a flashlight. Look; do not take anything apart.

• Faucets and showerheads. A faucet dripping once per second can waste more than 3,000 gallons a year (EPA WaterSense).
• Washing machine hoses. The Delaware Department of Insurance warns that rubber washer hoses eventually leak and that the damage “often goes undetected” (Delaware Department of Insurance).
• The water heater. Look for water on the floor, rust, or a dripping discharge pipe.
• Under sinks. Feel the supply lines and the cabinet floor for moisture.
• Ceilings, walls, and floors. Stains, bubbling paint, or a soft spot can mean a supply line is leaking behind them.
• Outside. Hose spigots, irrigation heads, and a wet or unusually green strip of yard between the house and the street.

Older homes deserve a closer look. The Delaware Department of Insurance lists old plumbing among the systems that “pose a higher chance of causing fire or water damage.” Spangler’s guide to older Wilmington homes covers which pipe types tend to fail first.

When to stop troubleshooting and call a plumber

Call a licensed plumber if:

• the meter or leak indicator keeps moving with everything off, and you cannot find the source,
• a toilet fails the dye test and a new flapper does not fix it,
• you find water damage: stains, wet drywall, warped flooring, or a wet spot that will not dry,
• you hear water running in a wall or under a floor when nothing is on, or
• you cannot find or safely operate your main shutoff.

If water is actively coming through a ceiling or onto a floor, shut off the main water valve inside the house if you can do it safely, and see what counts as a plumbing emergency. Do not operate the curb stop near the street. Artesian says that valve is its property and asks customers to contact it to have water turned off or on (Artesian Water).

Whose leak is it?

A leak on your side of the meter is usually your responsibility to repair. Artesian states that the customer is responsible for “promptly repairing any leak in the service line or any other pipe or fixture in or on the customer’s property” (Artesian Water). Where your side starts depends on your water provider. Spangler’s guide to who owns the water and sewer line to your house lays out the boundaries provider by provider. If water is surfacing in the street or at the curb, call your water provider first.

Frequently asked questions

Why is my water bill so high all of a sudden?

Usually one of three things: more water use (guests, irrigation, filling a pool), a billing change (an estimated read, a longer billing period, or a rate change), or a leak. A two-hour meter check with all water off tells you whether something is using water when nobody is (EPA WaterSense).

How do I check for a water leak in my house?

Turn off all water use, read the meter, wait two hours without using water, and read it again. If the reading changed, you probably have a leak (EPA WaterSense). Then dye-test every toilet and look for drips, wet spots, and stains.

Can a running toilet really raise my water bill?

Yes. A leaking toilet runs water straight down the drain, so you may not notice it. Put food coloring in the tank and wait 10 minutes; color in the bowl means it is leaking (EPA WaterSense).

My meter moves with everything off. Where is the leak?

The meter cannot tell you. Common sources include toilets, dripping fixtures, the water heater, supply lines behind walls or under floors, and the buried line between the meter and the house. A plumber can isolate the leak to a fixture, a branch, or the service line before anything gets opened up.

Who do I call about a high bill if I do not have a leak?

Your water provider. Rates, estimated reads, and meter accuracy are its responsibility. Artesian, for example, offers a meter test when you are certain a leak is not the cause (Artesian Water).

Found a leak you cannot track down?

If the meter keeps moving with the fixtures off, you find water damage, or you cannot locate the source, contact Spangler Plumbing to set up an inspection. Tell us what the meter did during your two-hour check and which toilets passed the dye test. We will narrow down where the water is going and give you a straight answer on the fix. Spangler serves homeowners in Middletown and across New Castle County. See all plumbing services, request service, or call 302-293-8008. For water actively coming into the house, use our 24/7 emergency line. Delaware Master Plumber #UT1488.