Water officials aren't giving up a nearly 30-year effort to get state approval to pump groundwater from arid valleys just west of the Utah state line and pipe it to faucets, fountains and fairways in Las Vegas.
The Southern Nevada Water Authority board decided Thursday to appeal last month's decision by Nevada's top state water official to deny the agency key groundwater use rights in parts of Lincoln and White Pine counties.
In a statement ahead of the unanimous vote, authority officials called the pump-and-pipeline plan a long-term water supply option aimed at cutting Las Vegas' reliance on drought-stricken Lake Mead and the Colorado River.
Federal water managers say a drier regional climate coupled with rising demand for water in the Southwest U.S. could prompt cutbacks in water deliveries to Arizona and Nevada by 2020.
Las Vegas is home to nearly three-fourths of the state population but the regional water authority says it uses less than 5 percent of the state's available groundwater supply.
Officials concede it would cost billions of dollars to build pumps and a pipeline to carry 75,000 gallons (284,000 liters) of water daily over a distance comparable to a drive from Los Angeles to Las Vegas. The water would be enough to serve more than 165,000 homes.
But they say it might become essential if drought keeps shrinking Lake Mead. The vast reservoir behind Hoover Dam supplies about 90 percent the water used by Las Vegas' 2.2 million residents and more than 40 million tourists a year. The lake was last at full capacity in 1983. It is now less than half-full.
After the water authority in Las Vegas started staking water rights in 1989 in the sparsely populated Spring, Cave, Dry Lake and Delamar valleys, critics filed lawsuits and branded the effort a water-grab.
Opponents and environmental groups in Nevada and Utah, including the Church of Jesus Christ of Latter-day Saints, argue that the parched valleys would be reduced to dust bowls. The Mormon church has a ranch in Spring Valley in Nevada.
The water authority maintains there is plenty of water underground, but that State Engineer Jason King was boxed into having to reject the pumping plan by "unprecedented requirements" and the broad scope of a December 2013 ruling by state District Court Judge Robert Estes.
Estes, from the White Pine County seat of Ely, rejected as "arbitrary and capricious" King's March 2012 approval of the pumping plan and ordered the state engineer to recalculate and reconsider.
King has also promised to appeal Estes' order. He maintains that it forced him to "upend the historical application of Nevada water law and water rights."