WATER

including the city and county of Denver, Pitkin County, Fort Collins, Grand Junction and Golden.

Those who draw water from wells will need to check their permits. Exempt well permits, for example, do not allow reuse of indoor water for outdoor irrigation.

If a grey water system saves 25 gallons per day and is installed in 500,000 homes, it could save 14,000 acre-feet per year. That’s enough water to supply 28,000 homes, Novick said.

But the counties that have approved grey water ordinances have seen little uptake. As of June, Denver had approved 30 systems; Castle Rock, 29 systems; and Pitkin County, zero, according to each county’s program manager.

Whether water efficiency measures translate into conservation in the Colorado River Basin depends on factors ranging from where a resident lives to local water management decisions.

Water pulled from the Colorado River Basin on the Western Slope never returns to the basin. Front Range residents could use less water in the hope that more water could stay on the Western Slope, but there are no incentives for Front Range water providers to give up such a valuable resource because of water savings, said MacGregor, the water law expert at CU.

“Anyone who pockets (water) savings can make a ton of money by selling those savings to another water user,” he said. “The question is, what is the mechanism for leaving water on the Western Slope through conservation?”

Even if a water efficiency program is enormously successful, cities and towns can still choose to use their water savings toward building new developments, rather than leaving them in reservoirs.

“This is the really frustrating part of what’s happened in a lot of areas. It’s like, you look at it, and efficiency has increased per capita, use has decreased over time, but we’re still susceptible to drought,” MacGregor said. “It’s because we’re not actually banking those savings.”

If at-home water efficiency measures are adopted widely, and the unused water is conserved for the future, those savings can help storage at local reservoirs and even help meet environmental and ecological needs by keeping more water in streams. It could even be