Study Finds Water Levels Average, Not Enough To Replenish Reservoirs

Aug 21, 2020

Lake Powell, one of the main reservoirs in the Colorado River Basin.
Credit Bernard Spragg

A study by the Bureau of Reclamation predicts that the current water levels in the Colorado River Basin will only postpone water shortages.

The study found that water levels in western reservoirs this year are similar to the past few years. John Berggren, a water policy analyst at Western Resource Advocates, said the overall trend in water levels over the past 30 years has been downward.

Because water levels have been in decline, Berggren said one good snow year is not enough to replenish the reservoirs. He said this year will only postpone water shortages by a few years.

"The significance of it [snowpack this year] is it pushed off what looks like severe shortages at least past 2021," said Berggren. "It looks like now the earliest we might see those shortages [are] maybe in 2022 or a year beyond."

In the past 20 years, water storage in the Colorado River Basin has decreased from 94 percent to 53 percent of capacity.

"The Basin has warmed about two degrees Fahrenheit in the last 50 years and we're learning more and more about the impacts on snowpack runoff efficiency and things just becoming less efficient," said Berggren. "Even if you get a big snowpack year, it's not translating into as much water in the river as it would have 30 years ago."

Berggren said dry soil, warmer air, and earlier blooms use up more water that doesn't end up in the reservoirs.

Have a question about this story? Please contact the reporter, Ashley Piccone, at apiccone@uwyo.edu