A top Bush administration water official said she doubts Nevada could win quick approval of a proposal to buy Colorado River water from farmers in California and Arizona.
Interior Secretary Gale Norton, the federal official who oversees Colorado River water allocations, did take a position on the idea. But she said Thursday in Washington, D.C., that discussions involving the seven states that share Colorado River water would be complex and could take years.
Assistant Interior Secretary Bennett Raley heard a pitch on the proposal last week from Sens. Harry Reid, D-Nev., and John Ensign, R-Nev., and Southern Nevada Water Authority chief Pat Mulroy during a tour of a wastewater treatment facility near Lake Mead.
Mulroy said Thursday she did not expect Norton to endorse the idea without consulting other states, but said she hoped for an urgent response with drought concerns mounting.
Mulroy said an interstate arrangement with Arizona to store unused river water on Nevada's behalf provides a legal precedent for more water trading.
States are eyeing a program in California that lets urban districts buy water rights held by farmers. Nevada officials want to bid for those supplies as well.
In an interview, Norton said a court consent decree, interstate compacts and agreements making up the law of the Colorado River were designed to give each state a certain amount of water.
"Its a different model to talk about moving water between states," she said. "That's obviously much more complex than water markets within a state."
The Colorado River is shared by Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming, as well as Mexico. The Las Vegas area depends on the Colorado River for 90 percent of its drinking water.
If the seven states fail to agree on a drought plan, and water levels continue to fall at Lake Mead and Arizona's Lake Powell, the federal government would revert to a 1922 agreement cutting Nevada's 300,000-acre-foot annual allocation by 4 percent.
An acre-foot is enough water to supply two single-family homes for a year.
Nevada currently uses almost all its allotment of Colorado River water.