How to reduce water and sewer bills--information for homeowners

Above: Water use in a residence



Toilet flushing is the primary use of water inside a home, so many of the best ways to conserve water involve toilets.

Toilets now available use 1.28 gallons per flush, compared to 3.5, 5 or more gallons per flush for models installed before 1994.

New toilets may pay for themselves in a few years by reducing your monthly water and sewer costs. We are happy to estimate your potential savings and payback from new toilets based on the number of people in your home, how much water the old toilets use, etc.

If it is not practical to replace an old toilet, you can conserve by putting a weighted container of water in the tank, adjusting the fill valve and/or flushing less often.

Some showerheads use as little as 1.5 gallons per minute, or 40% less than the plumbing code standard.

When it is time to replace a clothes- or dishwasher, we recommend choosing a water- and energy-conserving model.

If your water use goes up unexpectedly, the cause may be a leak in a toilet, faucet, pipe, etc. We recommend checking OWASA’s bills monthly to monitor your water use.

There are dozens of ways to save water and reduce your OWASA bills 

But some conservation practices and investments will save more water and dollars than others.

The information below is intended to help residential customers in deciding how to conserve water. This information may also be helpful in offices and retail businesses that do not have special water uses. 

Toilet flushing is the largest water use inside a home


Toilet flushing accounts for more than one-fourth of indoor water use in a home. Reducing the amount of water you flush is usually the best way to reduce residential water and sewer costs.

If your toilets were installed before 1994, you can save water and money every month by replacing them with new low-flush models. Some old toilets may use more than three times as much water as a new model.

High-efficiency toilets

use only 1.28 gallons per flush compared to 3.5, 5 or more gallons per flush for toilets installed before 1994.

The US Environmental Protection Agency’s (EPA’s) WaterSense program ( includes a list of toilets certified for efficiency.

For help in estimating the potential payback from replacing toilets, please contact OWASA at 919-968-4421 or

If it is not practical to replace an old toilet...

You can reduce the flush volume by putting a container of water in the tank. To keep the container from moving, you can put metal, stones, etc. inside. Or, fill the container with water to a level higher than that in the tank. The container should be placed carefully in the tank so it does not interfere with operation of the flapper, fill valve, flush lever and chain, etc.)

You may be able to adjust the fill valve so that the tank holds less water.

Or, you can flush less often (when you feel it is necessary).


Leaks can be costly and may damage flooring, etc. Some research indicates that leaks account for 14% of residential water use. 


Please review your OWASA bills for unexpected increases in water use, which may indicate there is a leak somewhere.

Check regularly for leaks in your plumbing pipes and fixtures (toilets, hoses, spigots, faucets, washers, irrigation system, etc.), and repair leaks quickly.

Toilets are one of the most common places for leaks. A leaking toilet could waste more than 100,000 gallons in a month.

To check a toilet, put food dye in the tank and wait 15 to 20 minutes without flushing. If dye appears in the bowl, there is a leak (probably at the flapper or fill valve).

When you replace a flapper, get one for use in water systems that use chloramines for disinfection.

If you fix a leak

Please contact our Customer Service staff at 919-537-4343 or to ask about getting a credit on your OWASA bill. We can give a credit once every three years, and there are some limits and conditions.

Our credit for fixing a leak does not cover all of the cost of the leaked water, so it is to your advantage to fix leaks promptly.

Showering and bathing

Take short showers (5 minutes or less). Showering for 5 minutes will also use much less water than a bath, which may use 40 gallons in a typical tub.

Install water-saving showerheads. Codes limit showerhead flows to 2.5 gallons per minute, but some showerheads use as little as 1.5 gallons per minute.

WaterSense ratings

The EPA’s WaterSense program ( also includes showerheads certified for efficiency.

Washing clothes and dishes

Wash dishes and clothes when you have a full load. When it is time to replace a dishwasher or clothes washer, choose a model with the US Environmental Protection Agency’s Energy Star label for saving water and energy (and dollars). For more information:  


Turn off the water when not needed to brush your teeth, wash hands, etc.

Install an aerator or a more efficient one to reduce water flow at a faucet.

Saving water outdoors

If you have “cold season” grass such as traditional fescue, consider replacing it with drought-resistant, non-invasive trees, shrubs or groundcovers which need little or no irrigation after they are established.

If you have a spray irrigation system, use no more than 1 inch per week and do not irrigate when it is raining or when the soil is still moist after rainfall. 

If you have an OWASA account, you can get our lowest water rates by conserving 

For individually-metered residences, OWASA has “tiered” water rates, which rise with the level of water use. For example, if you use 2,000 or fewer gallons per month, our lowest rate applies: $2.63 per 1,000 gallons.

If you use 3,000 to 5,000 gallons, our second lowest rate applies: $6.39 per 1,000 gallons. Water rates are higher for using 6,000 gallons or more per month.

How does your water use compare?

Water use in traditional single-family homes averages about 4,500 gallons per month per residence. Of course, your water use may differ from this average due to factors such as the number of people in the household, and the water efficiency of fixtures such as toilets. 

Reducing hot water use will also lower energy costs 

Using less hot water for showers and baths, washing clothes and dishes, etc. will also help reduce your electric and gas bills. Hot water use accounts for about 17% of energy use in a residence.

Conservation with a pressure reducing valve

If your plumbing system includes an adjustable pressure reducing valve (PRV), you may be able to conserve by lowering the pressure level.

In many homes with a PRV, pressure is set between 45 and  60 pounds per square inch, but you may have the choice of lowering this setting.

In addition to reducing water flows at faucets, spigots, etc., lower pressure may reduce the potential for leaks in washer hoses, pipes, spigots, faucets and other water-using devices.

Location of water shut-off valve

If there is a water shut-off valve in your plumbing system, please make sure you know where it is so you can quickly turn off the water if you have a leak.

To download a printable tag (shown below) which you can use to mark the location of the shut-off valve, please click here or contact OWASA at 919-968-4421 or

Water use and greenhouse gas emissions

All water and wastewater is pumped and most of the energy for pumping comes from fossil fuels. Conserving therefore reduces greenhouse gas emissions (GHG), a key factor in climate change. In providing 4,000 gallons of water and sewer service per month for a full year, OWASA uses about 363 kilowatt hours of electricity and this involves an estimated 334 pounds of GHGs.

For more information

Please contact OWASA at 919-968-4421 or or visit our Conservation and Education webpages.