The Library Media — National & World · National Desk
By Catalina Clarke
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Floods bring rare relief to U.S. Southwest reservoirs as Lake Powell rises 20 feet
Twenty feet of water arrived at Lake Powell in a matter of weeks — more than the entire spring snowmelt delivered — and the second-largest reservoir in the United States is still only just over a quarter full.
That is the shape of the Southwest’s water story this fall: real relief, arriving violently, into a system depleted enough that even a dramatic rise changes the picture less than the headline suggests. Lake Powell’s climb from its mid-September low dwarfed this year’s snowmelt gains, and 15 of its 17 boat launches remained unusable as of Friday.
The water came from the late-October and early-November storms that flooded communities across the region and forced hundreds of evacuations. Martin Hoerling, a hydrologist at the University of Colorado Boulder, estimated that the floodwater and further rain could total more than 1.2 million acre-feet — enough, on average figures, for about 4 million families for a year.
The Associated Press attributes the intensified heavy rain to El Niño, whose effects experts expect to last several more months. It followed a winter whose weak snowfall did little to recharge the region’s water bodies — one reason rain, rather than snowpack, is doing the work this season.
The relief is concrete in the places that measure water by the tap. Around Pagosa Springs, Colorado, about 7 inches of rain fell in October, and water restrictions affecting more than 10,000 people have been lifted. Upper Lake Mary, which supplies up to 40% of Flagstaff, Arizona’s water, has received more than 3 billion gallons since early October.
None of it settles the argument underneath. Under the federal Colorado River Lower Basin plan, California, Nevada and Arizona will collectively cut their use by 1.25 million acre-feet a year for the next two years — a figure, it is worth pausing on, roughly equal to everything this flood season is estimated to have delivered. Nevada and Arizona are challenging the plan in court. And the Bureau of Reclamation is unlikely to change releases from Lake Powell until the snowpack peaks around April, which means the reservoir’s new water sits inside an allocation fight that the rain did not resolve.
What the storms bought the region is time and margin — a quarter-full reservoir instead of an emptier one, restrictions lifted in towns that were rationing in October. What they did not buy is a new water picture. The Southwest’s reservoirs are filled by winters, and this winter has barely started.
For today’s conditions across the Southwest and the rest of the country, see The Library Weather.
Catalina Clarke
Editor-in-Chief, The Library Media
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