Dust is depleting snow runoff into the Colorado River, study shows

SALT LAKE CITY (ABC4) — A study led by University of Utah researchers found that mountain dust is accelerating snowmelt, leading to depleted snowpacks in the Colorado Basin.

“A lot of people assume air temperature is what controls the rate of snowmelt in the Spring, but it’s actually the amount of sunlight that’s absorbed,” said Professor McKenzie Skiles from the University of Utah.

The study largely focused on water levels originating from snowmelt in the Upper Colorado River Basin, a region with large amounts of dust that regularly blows onto mountain snowpacks. Researchers say dusty snow absorbs more sunlight, leading to a faster snowmelt.

“That additional energy that’s being absorbed accelerates the melt rate,” Skiles told ABC4.com.

According to Skiles, the amount of dust found in Utah snow is largely due to human activity, adding that settlements and widespread grazing have a particularly large impact on dust levels in mountain snow.

Researchers say current snowmelt models do not account for dust, leading to problems for water managers who rely on forecasts in yearly water allotments. According to Skiles, the time and rate at which snow melts determine our water availability.

Data from the Utah Department of Natural Resources shows 27% of Utahns use Colorado River water, while 60% directly benefit from the river.

Skiles says dust on snow primarily impacts Southern Utah, however, the Wasatch Front’s water supply is also affected.

“If we’re better able to understand the drivers of dust emission, we could predict how that would impact the snow for the rest of the season,” Skiles said.

Skiles was accompanied by other researchers from the University of Colorado, Boulder, Montana State University, the University of California, Los Angeles, and the University of Utah.