Residents more efficient in their water use

Despite a population boom in the western states, per-capita water use on the Colorado River has declined significantly in recent decades.

A new report by the Pacific Institute shows per capita use fell by an average of at least 1 percent a year from 1990 to 2008, a period that saw the population in the Colorado River basin swell by more than 10 million souls.

And some of the most impressive water-efficiency improvements came right here in the Las Vegas Valley, where individuals cut their use by roughly one-third while the population almost tripled.

"Southern Nevada ... use has declined dramatically" on a per capita basis, says researcher Michael Cohen, who authored the report for the Oakland-based environmental think tank. In 1990, the average valley resident consumed 347 gallons of water per day. By 2008, the last year included in the report, that figure had dropped to 248 gallons per day.

Doug Bennett, conservation manager for the Southern Nevada Water Authority, says the valley's per capita water use has gone down further since 2008 -- to about 223 gallons per day-- though he admits the economic downturn has probably been the main reason for that.

As the valley's population boomed, the Southern Nevada Water Authority and its member utilities responded by assigning watering days and banning front lawns for new homes. They started paying residents and businesses to rip out thirsty grass and make other efficiency improvements.

The Pacific Institute, critical of valley water management in the past, now identifies Southern Nevada as a shining example of efficiency improvement, alongside Albuquerque and Phoenix.

Of course, the report only looks at municipal deliveries, which still account for a mere 15 percent of total diversions from the Colorado. Some 70 percent of the water from the river system still goes to irrigate crops -- subsidized water uses that must still be addressed, if the region's population growth is to continue into the new century.

But Southern Nevadans have shown once again that they can adjust to a new set of realities.