For more than a century, a collection of deals, treaties and legal agreements have divided up the Colorado River’s water, a vital supply for 40 million people, seven states in the U.S. and two in Mexico, 30 federally recognized tribal nations and 5.5 million acres of agriculture.

Arizona will again go without 18% of its total Colorado River allocation, while Mexico loses 5%. The reduction for Nevada — which receives far less water than Arizona, California or Mexico — will stay at 7%. California won’t face any cuts because it has senior water rights and is the last to lose in times of shortage.

Arizona's Colorado River shortages will continue in 2026, but dry conditions and expiring agreements pose more uncertainty.