#LakePowell is critically low, and still shrinking. Here’s what happens next — KUNC #ColoradoRiver #COriver #aridification

Lake Powell, just upstream from Glen Canyon Dam. At the time of this photo, in May 2021, Lake Powell was 34% full. (Ted Wood/The Water Desk)

Click the link to read the article on the KUNC website (Alex Hager). Here’s an excerpt:

Lake Powell is in crisis. The nation’s second-largest reservoir is strained by more than two decades of drought, and its water levels are slipping dangerously low. In March, the reservoir passed an important threshold. Water levels dipped below 3,525 feet — the last major milestone before a serious threat to hydropower generation at the Glen Canyon Dam. The future of the reservoir is largely uncertain, but climate science and recent actions by the government are providing some hints as to what might happen in the near future…

Westwide SNOTEL basin-filled map April 16, 2022 via the NRCS.

Will water levels go back up?

In the short term, yes. In the long term, probably not. While levels are on a long downward trend, they fluctuate with the seasons. A large portion of the water in the Colorado River and Lake Powell comes from high-mountain snowmelt in Colorado and Wyoming. Because of that, the spring and early summer will bring a temporary boost to water levels while snow runs into rivers and eventually flows into Lake Powell. Mountain snowpack is generally below average for this time of year, so that boost may not be as big as it has been in years past.

Forecasts are calling for 4.1 million acre-feet of water to flow into Lake Powell from April to July this year, but water managers are obligated to release more than 7 million acre-feet out of the lake. An acre-foot is the amount of water needed to fill one acre of land to a height of one foot. One acre-foot generally provides enough water for one to two households for a year…

Brad Udall: Here’s the latest version of my 4-Panel plot thru Water Year (Oct-Sep) of 2021 of the Colorado River big reservoirs, natural flows, precipitation, and temperature. Data (PRISM) goes back or 1906 (or 1935 for reservoirs.) This updates previous work with @GreatLakesPeck.

What is the long-term future of Lake Powell?

All signs point to a hotter, drier future for the Western U.S. The big question is how water managers will divvy up a shrinking supply to feed a growing region. Climate change is driving more than two decades of drought across the region, and making it increasingly unlikely that Lake Powell will ever climb back to previous levels.

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