The Colorado River loses more than 19M acre-feet of water annually, but where does it go?
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According to a recently published study by researchers from Northern Arizona University, the Colorado River loses more than 19 million acre-feet of water to cities, farms and evaporation every year. That’s roughly the same amount of water used by the 50 largest cities in the country.
NAU professor Richard Rushforth helped author the study, which found that the amount of water used for farming has slightly decreased from 2020 — but agriculture remains a dominant use.
“Irrigation is what enables agriculture to function in these more arid places of the United States,” Rushforth said. “And so I think this is just amplified in the Colorado River basin because it’s, overall, a pretty dry basin.”
The seasonal heat raises water use as farmers try to keep their crops alive. Researchers found that in the upper part of the river, above Lake Powell, 90% of all the water used for farming in that area goes to cattle-feed crops like hay and alfalfa.
Still, Rushforth said it’s important to avoid focusing exclusively on agriculture and factor in users like big metropolitan areas.
“When you really step back and include those metropolitan areas that are dependent on the Colorado River, you start to see the enormous importance that this watershed has not just for the region, for the Southwest, but for the U.S. and abroad,” he said.
Recent renegotiations of legal agreements, said Rushforth, plus cuts over the last few years speak to the need to take a comprehensive look at how the river’s water is used and where it ultimately ends up. Years of previous research supported this recent study, which he hopes will help basin states negotiate and adapt.
