PHOENIX – Representatives from the seven Colorado River states were gathering Monday in Las Vegas to take one last shot at hammering out a drought plan, with a warning that chaos could result if they fail. At the best, if this week’s effort fails, the Interior Department would impose its own water-use guidelines on the states by the end of 2007. At worst, failure would mean a courtroom standoff that drags on for years, putting water supplies at risk if drought returns. “If we don’t have a plan to address shortages and we get to shortages, then we have chaos,” said Jeffrey Kightlinger, general counsel for the Metropolitan Water District of Southern California. “That’s not good for any state. I don’t think there’s an immediate risk … but shame on us if we can’t get a plan together when there’s no crisis.” The crux of the dispute has been who should suffer most if drought leaves the Colorado unable to supply full allotments. A seven-state proposal is due to the Interior Department this week. The Bureau of Reclamation plans to begin developing a range of alternatives for a shortage-sharing plan almost immediately, with a goal of releasing a first draft by March. Arizona’s Guenther believes a full-basin plan can be finished this week if critical lower-basin issues are resolved. But he said it’s also possible that more than one proposal could be forwarded. Patricia Mulroy, general manager of the Southern Nevada Water Authority, believes the states should consider any plan that would avoid a court battle. “For any one of the states to go to the Supreme Court is a declaration of war,” she said. “Once you do that, it shuts down the talks and the resulting damage takes decades to overcome.”160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! AD Quality Auto 360p 720p 1080p Top articles1/5READ MORESanta Anita opens winter meet Saturday with loaded card Coming to a drought agreement may come down to just two of the seven states – Arizona and California – coming to a truce. Nearly 40 years ago, Arizona agreed to give up senior status to more than half its share in exchange for the Central Arizona Project canal. California has resisted Arizona’s attempts to change that agreement, arguing that a deal is a deal. Other states have been willing to talk about ways to postpone declaring a shortage as long as possible, thus protecting Arizona, but only until low water levels put them at risk. Herb Guenther, director of the Arizona Department of Water Resources, said Arizona and California settled several key issues late last week about how the river’s major reservoirs will be operated but were forced to abandon talks on other points. Before the full-river issues can be addressed, the lower-basin states – Arizona, California and Nevada – must reach an accord. Meanwhile, upper river basin states – Colorado, Utah, Wyoming and New Mexico – also want to begin using more of their own allotments to help handle growing demands. They want assurances that their supplies will be protected from the three lower-river states.