LAS VEGAS -- It’s Mammon versus Mormon, as Las Vegas and its glittering towers of glass and greed seek to quench their growing thirst by draining billions of gallons of water from under the feet of a rancher whose cattle help feed the church’s poor.

The biblical battle across 275 miles of treeless ridges and baked salt flats comes as the western United States faces unprecedented droughts linked to climate change.

The surface of Las Vegas’s main source of water, Lake Mead, sits more than 100 feet below Hoover Dam’s spillways after reaching the lowest mark last summer since the dam was filled.

As it seeks new sources, the city’s water supplier is waging a court fight over plans to suck as much as 27 billion gallons a year from the valley that is home to the Mormon ranch and its 1,750-head herd, as well as three other rural valleys.

Casino resorts, five of which are Southern Nevada’s largest commercial water users, labor unions and the developer of a 22,500-acre mini-city west of Las Vegas argue their future depends on the water supply that the church, Indian tribes and environmental groups say is needed by local communities.

The fight, likely to echo across the increasingly arid West, conjures up the Los Angeles water grab, made famous in the 1974 movie “Chinatown,” that turned the once prosperous Owens Valley into a dust bowl.

As cities including Denver and Phoenix look to secure water for growing populations and economies, the prospect of mega- droughts, more severe and sustained than any in the 20th Century, looms over Nevada’s court battle, with one pipeline opponent calling it the “poster child” for future showdowns.

Spring Valley

The 7,000-acre Cleveland Ranch, established in Spring Valley in 1873 by Maine native Abner “Old Cleve” Cleveland and bought in 2000 by the Mormon Church, sits atop an aquifer a dozen-plus miles to the north of Route 50, known from postcards as “America’s Loneliest Highway.”

The ranch, owned by the Corporation of the Presiding Bishop of the Church of Jesus Christ of Latter-Day Saints, is worked by a combination of paid employees, church missionaries and other volunteers, according to a history of the ranch.

The calves, after they are weaned, are shipped to an Idaho feed lot and then to a processing plant, where some of the meat is frozen or canned as stew and beef chunks for distribution around the world.

If the Southern Nevada Water Authority wins in court, its proposed groundwater project may leave the valley to sage brush and coyotes, according to lawyers for the church and environmentalists.

‘Ancient’ way

“This is a huge project that raises fundamental questions,” said Paul Hejmanowski, a lawyer for the church. “Can we sacrifice an ancient way of life for a growing metropolis?”

So far, the ranch and other project opponents have fended off Las Vegas, convincing a judge in 2013 that there was insufficient scientific evidence for the state engineer’s decision to award the water rights.

The Nevada Resorts Association, the Nevada AFL-CIO, representing members of 120 unions, and developer Howard Hughes Corp. (NYSE: HHC) have thrown their support behind the water authority’s and state engineer’s petitions to the state Supreme Court for help. A hearing before the court hasn’t been scheduled.

“There are no other alternatives available, and it would increase the region’s water security,” said Virginia Valentine, president of the casino and resort trade group. “Our infrastructure needs to be there.”

Five casinos

The five resorts -- the Wynn Las Vegas, Mandalay Bay, Venetian, Bellagio and Caesars Palace -- consumed 2.4 billion gallons in 2013, according to the water authority.

Other large users include the golf and country clubs that surround Las Vegas, an area whose population has almost tripled since 1990 to 2 million.

The leisure and hospitality sector employs 28 percent of Nevada’s workforce and the taxes it pays make up 47 percent of the state’s general fund.

Those economics may doom Cleveland Ranch even if pipeline opponents have a good case, said Jeffrey Dintzer, a lawyer specializing in water-rights issues with Gibson Dunn & Crutcher LLP in Los Angeles who isn’t involved in the dispute.

“Money talks,” Dintzer said. “Nevada gets a huge amount of its revenue from gaming.”

If the Nevada Supreme Court doesn’t reverse the December 2013 decision by the state judge who second-guessed the state engineer, the Legislature and governor may step in to draft a compromise to ensure Las Vegas gets the water, Dintzer said.

That might not end the lawsuits. If the ranch and surrounding valleys are left dry, the state could face hundreds of millions of dollars in claims, he said.

‘Scarce’ commodity

“This will be one of many of these disputes I see coming in the future,” said Ed Casey, a water-rights attorney with Alston & Bird LLP, who represented Los Angeles in litigation over air pollution at Owens Lake. “Water is a commonly shared commodity, and as it becomes scarce, we have to face the question who gets priority.”

Ranchers, farmers and other so-called senior water rights holders may lose their place at the pump to growing cities, Casey said.

The Southern Nevada Water Authority is pursuing unassigned groundwater rights to reduce its reliance on the Colorado River, which accounts for about 90 percent of its supply and is subject to new upstream diversions, as drought conditions worsen.

Water needed

With Lake Mead -- the largest man-made reservoir in the U.S. -- at 43 percent of its capacity, the agency already has increased its use of recycled water and cut its per-capita use by 40 percent since 2002, said Bronson Mack, a spokesman for the authority.

Still, the agency expects to need new sources by about 2060, based on current estimates, or as soon as 2035 if population growth exceeds forecasts, Mack said.

The agency’s groundwater project calls for 263 miles of pipelines connecting Las Vegas with four valleys. U.S. approval of the pipeline is subject to a separate legal challenge in federal court.

As far back as 1989, the Las Vegas Valley Water District -- now part of the Southern Nevada Water Authority -- applied for unappropriated water in Cave Valley, Dry Lake, Delamar Valley and Spring Valley.

The state engineer didn’t rule on those applications until 2007, leading to the first round of litigation, which voided the approvals.

In 2012, the state engineer again approved most of the water authority’s applications, leading to a new round of court battles.

The Nevada case may set a precedent for urban water districts in arid and semi-arid regions looking for groundwater to sustain development, said Simeon Herskovits, a lawyer for counties, water agencies, environmental groups and businesses opposed to the project.

‘Poster child’

“This is kind of a poster child case for pro-development interests in urban centers trying to take water away from rural areas through a large infrastructure project by arguing, based on bad science, that vast amounts of water are available for extraction and export,” Herskovits said.

A defeat for the project may force water agencies in the West to find other alternatives, he said.

If Las Vegas builds the pipeline, an area the size of New England could face the same environmental and socio-economic devastation as California’s Owens Valley after completion of the 200-mile Los Angeles Aqueduct in 1913, he said.

Healthy calves

Cleveland Ranch and other opponents persuaded Senior District Judge Robert Este in Ely, the only city within 100 miles of Spring Valley, that it was premature to approve large scale pumping before its effects were fully known.

He directed the state engineer to further develop mitigation protocols for any “unreasonable” effects of the project.

While the church declined to discuss Cleveland Ranch, its lawyer provided a copy of a DVD about the ranch that details its operations and makes the case that an abundant water supply is essential to raising healthy calves. The DVD was submitted as evidence in the court fight.

The Nevada Supreme Court on Feb. 6 dismissed the water authority’s appeal of Este’s decision, saying it wasn’t ripe for review because the judge sent the case back to the state engineer without issuing a final judgment.

In a second bid, the water authority and the engineer asked the state’s seven-member high court to use a procedure called a writ, which doesn’t require a final judgment in the underlying case, to overturn Este’s decision.

They contend the judge acted “arbitrarily and capriciously” by substituting his judgment for that of the state engineer, an expert in hydrology.

“The worsening drought conditions in the West generally, and the Colorado River Basin in particular, do not afford the luxury of time,” the water authority said in a Dec. 12 court filing. “This court should hear this petition, and resolve these issues, now.”

The case is Southern Nevada Water Authority v. Seventh Judicial District Court, 65775, Nevada Supreme Court.