Standard low flush toilets (since 1994), use 1.6 gallons of water per flush while older models use between 3.5 and 7 gallons per flush. Save more water with WaterSense-labeled high-efficiency toilets that use 1.28 gallons of water or less per flush.

An average household could save up to 2,400 gallons of water per month by replacing a 1950s-era toilet with a high-efficiency toilet. Even toilets that use 1.6 gallons per flush provide water and sewer bill savings that pay for the cost of replacing a toilet in three years or less.

More about toilets

Not ready to replace your toilet?

• Reduce water used per flush by installing an object that displaces water in the toilet tank. A plastic bottle weighted with water or gravel works well.
• Don't use bricks and old milk cartons. These deteriorate and can reduce the effectiveness of your toilet’s valves or its overall function.
• Make certain that the displacement device does not block any moving part inside the toilet tank or you could cause your toilet to run and waste water.

A silent toilet leak, often caused by a flapper that does not completely close, can waste 50 to 500 gallons of water per day. A silent toilet leak that wastes 250 gallons of water per day would cost a city of Tacoma resident more than $40/month in water and sewer charges.

QUICK TIP

Check your toilet for leaks:

1. Take the lid off the tank, flush and watch for water to come up to the mark impressed into the ceramic of the tank.
   If water comes up higher than the mark level impressed into the ceramic of the tank, it's easy for water to continuously overflow and run down the drain. If necessary, bend the float arm down so that the re-fill valve shuts off at the mark impressed into the tank. If the re-fill valve leaks, you may want to work with a plumber.
   
2. Put a little food coloring into the tank.
   This will help determine if a leak exists in or around the flapper at the bottom of the tank.
   
3. Don't flush. Wait to see if any color appears in the bowl. 
   If color appears, you probably have a leak at the flapper valve on the bottom of the tank. Flapper leaks can be caused by a worn flapper (easily replaced) or by a corroded flapper valve seat, which needs to be replaced by a plumber. If you replace the flapper, make sure you buy the right one for your toilet. The wrong flapper model may also leak.
   
4. Flush your toilet to get rid of the food coloring.