Arizona, California and Nevada have narrowly averted a regional water crisis by agreeing to reduce their use of Colorado River water over the next three years. This deal represents a temporary solution to a long-term crisis. Nonetheless, as a close observer of western water policy, I see it as an important win for the region.
Seven western states – Colorado, Wyoming, Utah, New Mexico, Arizona, Nevada and California – and Mexico rely on water from the Colorado River for irrigation for 5.5 million acres and drinking water for 40 million people. Their shares are apportioned under a compact negotiated in 1922. We now know, thanks to tree-ring science, that its framers wildly overestimated how much water the river contained on a reliable basis. And climate change is making things worse.