Most likely, you're currently dumping more than a gallon of drinkable water down the sewer each time you flush.

If you're using a toilet built before 1994, you are wasting 3.5 gallons or more per flush, and if you've got a toilet made after the U.S. Congress's Energy Policy Act of 1992 mandated only "low-flow" models be sold after 1994, then the good news is you're only wasting 1.6 gallons per flush.

Either way, that is a lot of water wasted per flush. And while there is plenty to be said for changing people's behavior in the bathroom, a number of innovations in recent years have bypassed the whole behavior-change process, so that saving water in the loo is a no-brainer.

Below and on the subsequent pages are some of the water-saving toilets of the future, hopefully coming soon to a water closet near you.

Low-Flow Toilets

In 2007, the U.S. Environmental Protection Agency issued a final specification for the latest generation of low-flow toilets, ones that use 1.3 gallons of water or less per flush. But what about even more water-efficient models?

Last fall, the EPA went one step further with the release of the first WaterSense certification for ultra-low-flow urinals, which use .5 gallons per flush or less.

Pictured below are ultra-low-flow urinals from Zurn, Sloan and American Standard; each use one pint or less of water per flush.

Next page: No-Flow Urinals