Global Water Security Center

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The American Southwest needs more than rain

This opinion article was written by Penny Beames and Misty Mathews and originally appeared April 14, 2023, on LinkedIn.

Yes, the American Southwest saw a lot of rain this winter. While rain is welcome in this drought-stricken region, one exceptional year will only go so far toward replenishing the reservoirs that provide power and water to millions of people in the lower Colorado River basin.

Thanks to La Niña, the Southwest got about 65% more precipitation than normal during the early part of the season, according to But one season with higher-than-average rain is not enough to overcome a 23+ years megadrought (Environmental Protection Agency).

Meanwhile, the Sierra Nevada snowfall total for winter 2023 was the second-highest it’s been since record keeping began, according to the UC Berkeley Central Sierra Snow Lab. The river’s major reservoirs, Lake Mead and Lake Powell, depend heavily on spring runoff, but the impressive total will barely put a dent in the shortfall.

Considering all this, drastic action is required to avoid Lake Mead in particular from shrinking below levels required to produce power and release water downstream. To entirely lose flow through the Hoover Dam that creates Lake Mead would be catastrophic. But that’s tough to accomplish with so many interests competing for the same resource. Major cities like Las Vegas and Los Angeles, agricultural land in California, hydropower throughout the basin, all vie for what they see as their share.

The three states who share water downstream from Lake Mead—Utah, Arizona, and California—have spent years trying to reach consensus on who should reduce their water intake and by how much. They’ve spent much of those years in a stalemate.

Part of the issue is that these inflexible institutional arrangements hinge on historical water allocations from an amount of water the river never actually had. The now 100-year-old estimates of the river’s annual flow were optimistic at the time and grow more inaccurate as a shifting climate dries the region. 

The federal government rarely flexes any muscle in the debate. But now, the Biden administration has announced two proposals to spur the process along. They propose either spreading reductions along seniority lines, where Utah and Arizona would bear the heavier brunt of reductions than senior water user California, or to just take equal amounts off of each state’s water allocation. 

Whether either of these proposals are enacted remains to be seen. Perhaps neither will. It could be that they are enough of a painful reminder that you can’t take more out of any system than gets replenished. Even with a reservoir as big as Lake Mead, that math is unsustainable. And that’s what the states have been doing for years.

California, Utah, and Arizona will need to come to the table, perhaps with federal help, to decide how they’ll collaborate to prevent Lake Mead and the Colorado River from fully running dry. This year’s wet winter may have bought them some time. But much like the water, time is running out.

Read more at Vox.