Ever since the 1992 Energy Policy Act banned sales of 1.6-gallon toilets that used 3 to 5 gallons per flush, homeowners have been searching for an effective low-flow toilet. It’s been an elusive hunt. Double-flushing (wasting even more water) to fully clear a bowl seemed the only solution.

Over the years, wider pipe openings and pressure-assisted pumps slowly improved performance. Today we have a new generation of high-efficiency toilets that use less than a gallon of water.

To help consumers find these water misers, in 2007, the Environmental Protection Agency began giving a new seal of approval to low-flow toilets. Look for the WaterSense label, awarded to any toilet that uses 20 percent less water than the standard 1.6-gallon models. "The label lets consumers know with certainty that they’re choosing products that use significantly less water without worry whether those products will perform well," says Rob Zimmerman of Kohler Co.