A set of guidelines for managing the Colorado River helped seven Western states through a dry spell.
But the U.S. Bureau of Reclamation says it's not enough to keep key reservoirs from plummeting amid persistent drought and climate change. Millions of people in seven states and Mexico rely on the river for drinking water and growing crops. The bureau was tasked with evaluating the effectiveness of the 2007 guidelines that give the states an idea of how much water to expect each year. It released a report Friday saying stronger measures are needed in the future. States, tribes and others will use the report to start negotiating what will replace the guidelines in 2026.