Water-Efficient Toilets

Water efficient toilets are designed to remove waste by increasing the water velocity rather than increasing the water volume

Why is it important to have water efficient toilets?

Water efficient toilets reduce water bills and help to greatly reduce water usage in homes and businesses. On average, toilets account for nearly 30% of a home’s water usage, and they can use up to six gallons of water per flush. Old toilets are often also the cause for water waste through leaks. Nowadays, water-efficient toilets can use anywhere below 1.6 gallons per flush. By replacing old toilets with water efficient ones, we can cut water consumption by 25% or more. If all toilets in the United States were replaced with water-efficient toilets, up to 640 billion gallons of water could be saved per year. This metric further implies the degree of water conservation that these efficient toilets promote. Water-efficient toilets greatly cut the cost of water bills, and are equal or superior in usage to water-inefficient toilets. By reducing the amount of water used by 20 to 60 percent, you can save nearly 13,000 gallons of water per year (imagine how much water a school could save).

What qualifies as a water efficient toilet?

Water efficient toilets need to use under 1.6 gallons of water per flush, but 1.28 GPF or less is preferred.

→ Reduces water consumption by 54%

→ A lot of the new and more water efficient toilets have dual flush which decreases the water usage per flush even more

→ Using toilets that come with 2 flush options: one large, one small, helps reduce water usage; “dual flush”

→ “WaterSense” is a program sponsored by the US EPA (Environmental Protection Agency). When this label is used, it indicates that the toilet is water-efficient and high performance

→ “Energy-efficient toilets...are designed to remove waste by using water velocity instead of removing waste by using water volume”


Which Type of Toilet is Right for You? From the Massachusetts Water Resources Authority

Consider which of the residential low-flow toilet types is best for your home:

  • Gravity Toilets are the most common. Water is stored in a tank and when flushed, the water is released through a flapper valve and driven by gravity to clear out the bowl. These toilets require approximately 10-15 pounds per square inch (psi) of pressure at the connection to function properly. Gravity toilets are relatively inexpensive, ranging from $100-$200.

  • Pressure Assisted Toilets are hybrids of gravity and flush valve toilets. A pressurized tank placed inside the porcelain tank compresses a pocket of air and releases pressurized water into the bowl and out the trapway at high velocity. The flushing action of these toilets is noisier than the gravity types’, and they require a minimum water pressure of 25 psi to operate properly. Prices for these toilets are usually over $200.

  • Flushometer Toilets are found in most commercial buildings. They have no tank but rely instead on a pressure-operated valve directly connected to the building’s water supply. They require a large supply pipe and a minimum water pressure of 23-40 psi to operate well. These toilets are priced at about $300.

What factors contribute to whether a toilet qualifies for a rebate?

→ You can determine if a toilet qualifies for a rebate based on:

  • the year when your home or building was built,

  • the manufacture date stamp

  • the toilet’s flush volume

→ Knowing the flush volume can help determine a toilet’s age because certain flush volumes were only manufactured during a specific time period.

→ Must replace a non-water saving toilet (3.5 or more gallons per flush) with a water saving toilet

→ Must include a proof of purchase and a copy of the approved plumbing permit application