The Bellagio Fountains gush 460 feet (140.2 meters) high every 15 minutes nightly. Golf courses carpet the desert, as they have since Frank Sinatra and the Rat Pack played Las Vegas. And the casino restaurants still serve water without asking.

The 2 million residents and 43 million visitors a year in the Las Vegas area might never know that their principal water supply, Lake Mead on the Colorado River, is almost the lowest since Hoover Dam created it in 1936. Engineers are boring through rock in an $817 million race to lower the city’s water intake to keep up with the sinking lake level.

“Just because you have one good year of water every eight years doesn’t change the long-term trajectory of the river, which is distinctly downward,” said Rob Mrowka, a senior scientist in Las Vegas with the Center for Biological Diversity. “We’ve got a crisis at hand and a catastrophe in the making.”

If the severe drought gripping the American West continues, Las Vegas may find itself on the losing end of an increasingly intense battle to obtain water. While conspicuous consumption in a desert playground may work in times of plenty, Las Vegas and its thirsty suburbs will need to adapt to changing conditions, Mrowka said.

Regionally isolated from abundant water sources, Las Vegas hasn’t done enough to ensure a steady supply, failing to anticipate what may become a long-term shortage, said Bart Miller, water program director for the conservation nonprofit Western Resource Advocates, based in Boulder, Colorado. The metro area needs to wean itself from historic dependence on a small share of the Colorado River, Miller said.

‘World of Hurt’

“Las Vegas, because they’re a very dry place and limited to this allocation from the Colorado River, needs to accelerate their efforts to be as water-efficient as they can be,” Miller said. “If we don’t take action, we’ll be in a world of hurt.”

In Nevada, the driest state in the nation, master-planned communities with fountains now ring artificial lakes formed with water diverted from that river, even though the state is entitled under compacts and court rulings to just 2 percent of its water.

Mrowka was environmental manager for Clark County, which includes Las Vegas, in 2003 when it adopted conservation measures including a prohibition on new lawns. He said the region hasn’t done enough to limit water consumption indoors, to end profligate uses such as man-made lakes and fountains, and to explore supplies other than the Colorado River and a proposed pipeline, currently challenged in court, to divert rural groundwater from eastern Nevada.

Short Attention

“People have a very short attention span,” Mrowka said. “We’re not doing nearly enough that needs to be done.”

The neon-lit casinos of the famed Las Vegas Strip have demonstrated some awareness of the water shortage. The 22 million gallons of water in the eight-acre lake supplying the Bellagio’s fountains is recycled. Las Vegas-based owner MGM Resorts International is also saving water through automated irrigation systems, high-efficiency dishwashers and linen reuse, spokeswoman Rachel Rogala said.

Water use per person fell 40 percent between 2002 and 2013, according to data from the the Southern Nevada Water Authority, the water agency that serves the Las Vegas metropolitan area.

The conservation measures allow Las Vegas, with 150,000 hotel and motel rooms to fill, to keep up business as usual. Sin City is the economic hub of Clark County, which is home to almost three-fourths of Nevada’s population and the center of the state’s largest industry, leisure and hospitality. The county calculated tourism’s impact at $45.2 billion last year, including $9.7 billion spent on gambling.

West’s Largest

Nevada’s primary source of water, the Colorado, draws from as far north as Wyoming. Runoff from the Rocky Mountains and other ranges, flowing into the largest river in the West, is apportioned among the states of Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming. Nevada gets the smallest share, about 2 percent. California gets the most, about 27 percent.

“It has a lot to do not with what happens in Vegas, but what happens in California, Arizona and even Mexico,” where the river ends, said Douglas Kenney, director of the Western Water Policy Program at the University of Colorado Law School in Boulder. “The stability of their water supply depends on the overall seven-state management of the river.”

The allocations were set through a series of agreements and court cases dating to the 1920s and reflecting population and water use patterns at the time.

Population Boom

Nevada’s population was about 77,000 in 1920; today it’s about 2.8 million, according to Census Bureau data. Nevertheless, “the parties aren’t going to reallocate the river,” Kenney said.

Lake Mead is at about 45 percent of capacity. Its surface elevation as of April 11 was 1,099.24 feet above sea level and is projected to drop to 1,082 feet by the end of the year, according to U.S. Bureau of Reclamation spokeswoman Rose Davis.

The falling level is drawing closer to Las Vegas’s water intakes. One will become inoperable at 1,050 feet, the other at 1,000 feet. In September, Ronald Zegers, assistant general manager of the Southern Nevada Water Authority, said the lake could fall low enough to render one intake pipe inoperable by the spring of 2015.

Since 2008, contractors have been boring through rock to create a third conduit that would draw water from as low as 860 feet above sea level, said Nicole Lise, a spokeswoman for the authority.

As of September, Zegers said in a report to the board, the new pipeline was almost a year behind schedule.

To contact the reporter on this story: James Nash in Los Angeles at To contact the editors responsible for this story: Stephen Merelman at Pete Young, Jeffrey Taylor.

Photo Credit: A night view of the Bellagio and Las Vegas from above. O Palsson / Flickr