This year’s predicted spring runoff into Lake Powell has decreased yet again as the impacts of a dry winter begin to show.
Hydrologists at the Colorado Basin River Forecast Center said Wednesday that the amount of water flowing into Lake Powell between April and July this year is expected to be 55% of average. “Average,” in forecasting, refers to the average runoff between 1991 and 2020.
That prediction follows a decline in forecasted flows since the start of winter.
In December, hydrologists said Lake Powell’s runoff would be 92% of average. That forecast fell to 81% in January and even further to 67% in February. The prediction ticked up to 70% in March due to heavier precipitation before dropping to the current forecast of 55%.
Cody Moser, a hydrologist at the forecast center, said the snowpack and water supply outlook was “off to a promising start December 1...and then basically, since mid-December, we’ve been tracking below-normal above Lake Powell.”
In terms of actual water, 55% of the average runoff translates to about 3.5 million acre-feet of water making it into Lake Powell. An acre-foot is enough water to sustain two Utah households for a year, according to the Utah Division of Water Rights.
That’s lower than the runoff in 2022, which was a little over 3.7 million acre-feet, but better than 2021’s 1.85 million acre-feet. Spring runoff in 2023 and 2024 were well above what is forecasted this year.
The snowpack above Lake Powell, which is the second-largest reservoir in the U.S., has already begun to melt.
At the start of April, the snowpack was 89% of the 1991-2020 median. As of May 1, it has shrunk to 71% of the median.
“It’s not looking likely that things are going to improve significantly this season,” Moser said Wednesday.
Part of the low runoff prediction is due to dry soil conditions above Lake Powell. Dry soil soaks up water from melting snow that would otherwise make it into the Colorado River and ultimately into the reservoir.
This year’s lackluster forecast comes as the seven states that share the Colorado River’s water are in deadlocked negotiations about how the river and its reservoirs should be managed after current guidelines expire at the end of 2026.
The states — Arizona, California, Colorado, Nevada, New Mexico, Utah and Wyoming — primarily disagree over which of them should have to decrease their water use, and by how much.
At the same time, over half of Utah is experiencing drought conditions. Gov. Spencer Cox declared a state of emergency due to drought for over half of the state’s counties in late April.
