Depending on where you live, water scarcity in the U.S. may not be appear to be a critical issue—at least not yet. But the fact is regions like Nevada and Colorado are facing serious water shortages right now. In their paper, “When will Lake Mead go dry?” researchers Tim Barnett and programmer/analyst David Pierce state that there is a 50% chance Lake Mead, the largest reservoir in the U.S. in maximum water capacity, will be dry by 2021 if future water usage is not curtailed. What’s more is that the government projects that at least 36 U.S. states are anticipating local, regional, or statewide water shortages by 2013, even under non-drought conditions.

That’s pretty critical.

Southern Nevada is one region that has taken the lead on water efficiency. Partnering with the Southern Nevada Home Builders Association (SNHBA), the Southern Nevada Water Authority (SNWA) has developed the Water Smart Home program, which certifies both new homes and neighborhoods.

Similar to the EPA’s WaterSense New Homes program, SNWA’s Water Smart Home program sets requirements for indoor and outdoor water usage, including landscape design, irrigation systems, plumbing, appliances, and swimming pools. According to SNWA, a Water Smart home can save as much as 75,000 gallons of water per year per home compared to a home built a decade ago.

To encourage participation, the program offers several incentives, including rebating consumers $1.50 per square foot for grass that is removed and replaced with desert landscaping. The program also offers coupons for pool covers, irrigation controllers, and rain sensors.

The video below provides an overview of the Water Smart Home program and includes some specific examples of how it is building more water-efficient homes.