Las Vegas Environmental Issues

View of Bellagio Fountain, Bally's and Paris Casinos in Las Vegas, Nevada, US. Photograph: Corbis Cattle ranchers, Native Americans and Mormons fear US state's chief engineer will allow 300-mile pipeline to tap groundwater

• Map: water pipeline proposals

There was a time during the cold war when the Pentagon wanted to bury hundreds of nuclear missiles in the vast emptiness of Nevada, in case the United States came under attack from the Soviet Union. In a 21st-century version of an existential struggle in the desert, the city of Las Vegas wants to pump up to 300bn litres of water a year out of this landscape and transport it 300 miles south to the thirsty metropolis of casinos and golf courses.

The most advanced of three such projects as the US south-west struggles to adapt to recurring droughts, the pipeline could get the go-ahead on Thursday from the state's chief engineer.

Supporters say the $7bn (£4.4bn) project is a matter of life-or-death for Las Vegas, which, some projections suggest, could run out of drinking water in 20 years. Opponents of the pipeline say draining the desert of groundwater would destroy the livelihoods of the cattle ranchers, Native American tribes, and Mormon enterprises that call this expanse home, and reduce a vast swath of the state to a dust bowl.

"It will devastate this part of the state, " said Dean Baker, a lean man well into his 70s. He and his three sons, now in their 40s, have grazing rights to 160, 000 hectares of land straddling the Utah-Nevada state line.

In its current incarnation, the network of pipelines and pumping stations striking out from Las Vegas to four valleys in eastern Nevada would terminate near the Bakers' property. After 50 years on the land, Baker is convinced the scheme would dry up the natural springs that feed his cattle herd and water his alfalfa and hay fields. Federal government scientists have made similar predictions.

Vegas would get its water, Baker said, but it would destroy the ranches that supply its food. "I think it will hurt Las Vegas. I think it will hurt the whole state of Nevada, and if it's ever done – 50 years from now, 100 years from now – there will be a huge amount of people saying: 'What on earth? How did it happen? How could they have done something that stupid?'"

The stretch of Route 50 that passes near Baker's ranch claims to be the loneliest road in the US. Cows, sheep and the occasional herd of deer meander along it. Apart from the people who lived out here, few were fully aware of how much water lay beneath the desert until the late 1970s, when engineers siting those cold war nuclear missile silos drilled into sizeable underground reserves.