Arizona was the only state that required legislation to join the agreement to protect the water that serves 40 million people in Wyoming, Colorado, Utah, New Mexico, Arizona, Nevada and California.
U.S. Bureau of Reclamation
The drought plan requires Arizona to find a way to reduce its use of Colorado River water by up to 700,000 acre-feet — more than twice Nevada's yearly allocation under the drought plan.
The other six states in the Colorado River basin have agreed to plans that recognize a long-running drought, the dwindling supply of water and how they intend to cope with it.
A deal was supposed to be signed by the end of 2018, under threat that the water levels on the river would push the federal government to impose its own restrictions.
Colorado River water supports about 40 million people and millions of acres of farmland in the U.S. and Mexico.
Arizona water managers have been leading a series of biweekly meetings since July to work out details of the proposed drought-contingency plan.
Drought has severely affected reservoir levels in Colorado and water supply is well below normal in almost all of the state’s major basins.
The chances of a shortfall in Lake Mead, the Colorado River’s biggest reservoir, are now 57 percent, up from the 52 percent projected in May.
A vital reservoir on the Colorado River will be able to meet the demands of Mexico and the U.S. Southwest for the next 13 months.
In Colorado, the Arkansas benefits from an injection of water from the Fryingpan River on the other side of the Sawatch Range.