As Reservoirs Recede, Fears of a Water Shortage Rise

Five years of record-breaking drought in the Colorado River basin have drained Lake Powell of more than 60% of its water. Flows on the Colorado are among the lowest in 500 years.

Downriver, Lake Mead, the biggest reservoir in North America and supplier of water to Southern California, Arizona and Las Vegas, is little more than half full. At Mead's northern end, the foundations of St. Thomas, a little town demolished in the 1930s to make way for the reservoir, have reemerged.

The 1,450-mile-long river that greens 3.5 million acres of farm and range land and helps feed the faucets of 25 million people may within a few years lack the water to quench the West's great thirst. For the first time ever, the seven states that rely on the Colorado are confronting the possibility of a shortage.

"They've never had to face a shortage of this consequence," said Pat Mulroy, head of the Southern Nevada Water Authority that supplies Las Vegas, one of the most river-dependent cities in the Colorado basin. "When you're right up against it and facing the possibility of inadequate supplies to municipalities or farmers or jeopardizing recreation values, these are very tough choices."

The states are meeting now to try to figure out how they will deal with a shortage if the drought continues. As with everything else on the heavily regulated Colorado, the answers will be found in a complex tangle of law and politics.

If the law of the river was strictly followed, cuts would be made according to a hierarchy of water rights, with Arizona, Nevada and the upper basin states of Colorado, Wyoming and Utah taking the first hits. California, which gets about 14% of its statewide water supply from the river, has some of the most senior rights on the Colorado and is in a comparatively good position.

But the states may try to avoid triggering cuts. One approach would be for utilities to buy water from farmers and growers -- who use 80% of the river's water -- and send it to cities.

"With voluntary transfers you can easily take care of the big urban needs in the lower basin with compensation to farmers, and you don't have to dry up agriculture to do that," said Robert Johnson, the lower Colorado regional director for the U.S. Bureau of Reclamation, which operates the dams and reservoirs that make up the river's vast plumbing system.