Saving Water with a High-Efficiency Toilet

Saving water by installing a new high-efficiency toilet can shave $90 off your utility bill, and send thousands fewer gallons down the drain.

Dual-flush toilets, like this one, have two buttons, one for half flushes and one for full flushes. Image: Caroma

Today’s high-efficiency toilets use even less water than the federal standard of 1.6 gallons. If you’re in the market for a new throne, it pays to consider a high-efficiency toilet. You’ll save a bundle: According to the EPA, replacing pre-1994 guzzlers with new high-efficiency toilets will shave more than $90 off your annual utility bills. Plus, you’ll be sending about 4,000 fewer gallons a year down the drain.

Look for high performers

The EPA’s WaterSense label on the packaging will identify high-efficiency toilets that are certified by independent laboratories. They’re rated according to Maximum Performance (MaP) testing protocols, which measure the toilets’ ability to remove waste.

MaP scores range from 250 to 1,000, based on the number of grams completely evacuated in a single flush. The EPA has adopted 350 grams as its minimum performance threshold, and anything over 500 is considered very good.

Choose a flush mechanism

Like standard low-flow toilets, a high-efficiency toilet comes with different flush options. The high-efficiency toilet you choose depends on how “green” you want to be, how much you’re willing to spend, and your tolerance for noise.

  • Gravity flush toilets rely on the weight of water flowing into the bowl to help remove waste. Most residential toilets in the U.S. are this type.
  • Pressure-assist toilets compress air at the top of the tank to increase velocity, so they can do the job with as little as 0.8 gallons of water. While this turbocharged action makes for a powerful flush, the loud “whoosh!” may cause small children to jump out of their socks.
  • Dual-flush toilets have buttons that let you choose between a half flush and a full flush, depending on whether liquid or solid waste needs to go down. Caroma, a brand made in Australia (where dual-flush is mandatory), offers nearly a dozen dual-flush lines.
  • Tankless designs use electric pumps. While that delivers a powerful flush without excessive noise, this type of high-efficiency toilet requires electricity, which can make for more complicated installation and costlier maintenance.

The price of water-saving comfort

Basic water-saving, high-efficiency toilets cost no more than conventional low-flow toilets, but the price range is wide: You can spend anywhere from $200 to $1,000 and more. Certain features, such as elongated bowls and high-tech finishes, add to the price.