Prompted by years of drought and mismanagement, a series of urgent multi-state meetings are currently underway in Las Vegas to renegotiate the use of the Colorado River. Seven states and the federal government are close to a deal, with a powerful group of farmers in Arizona being the lone holdouts. The stakes are almost impossibly high: The Colorado River provides water to 1 in 8 Americans, and irrigates 15 percent of the country’s agricultural products. The nearly 40 million people who depend on it live in cities from Los Angeles to Denver.