Dust settling on local peaks has a big impact

Water managers are concerned

The mountains surrounding Crested Butte are looking more like windswept dunes than alpine peaks. The dust is back: reddish-brown zebra stripes on Red Lady Bowl and full dirty blankets on many of the peaks visible from town and the mountain. There’s really nothing good about it—the dust wreaks havoc on the spring snowpack by accelerating snowmelt rates—creating challenges for water managers, ranchers and backcountry skiers alike.

The fourth dust-on-snow event of the spring took place Monday, April 12 and carried over into the next day, according to Chris Landry, a dust-on-snow expert and director for the Center for Snow and Avalanche Studies in Silverton, Colo. Landry just returned from an 1,100-mile road trip that took him to 11 dust-on-snow study sites around the state, including sites at Taylor Park and Spring Creek.
“Dust has already accelerated snowmelt at the sites that we monitor,” Landry said. The dark dust layers reduce the snowpack’s albedo, or reflectivity, thus absorbing more solar radiation than a clean, white snowpack.
Landry said the dust is sourced from the “Colorado Plateau at large,” and not necessarily one specific location. The source location changes from storm to storm. “Conditions vary out there over time and space—it’s a large landscape,” said Landry.
The Center for Snow and Avalanche Studies also collaborates with the Snow Optics Laboratory at the University of Utah.
When Landry visits the 11 monitoring sites, he digs a normal, but very fine, snow pit and collects a series of 3cm x .05 square meter samples. Those samples are then melted and filtered and the mass of dust is quantified at milligrams per square meter.
Soon after a dust event occurs, they also collect a larger, .5 square meter sample from the Swamp Angel monitoring site near Silverton, Colo. There are also devices at each site that measure incoming and reflected solar radiation, indicators of the snow’s albedo.
According to Center for Snow and Avalanche Studies assistant to the director Kim Buck, almost all of the state’s water districts are helping to fund the research, and there’s the potential for this work to be applied to larger scale western hydrology.
Landry said, “The Colorado Dust on Snow [CODOS] project is really being exclusively funded by water stakeholders.”
“We as water managers are definitely concerned with the impact,” said Frank Kugel, general manager for the Upper Gunnison River Water Conservancy District. “It’s always better when you have clean snow and it stays there as long as possible. A more gradual, prolonged runoff benefits users in the basin—otherwise it just goes downstream before we can put it to beneficial use.”
Landry hesitated to compare the impacts of dust on Crested Butte to other areas in the state, as this year’s data is still being collected and analyzed. He did say, as a whole, this year’s dust events are a “close second” to what we saw last spring.
Landry will hit the road again shortly for a return trip around the state to collect more dust-on-snow data. He is scheduled to make a CODOS presentation at the Upper Gunnison Water Conservancy District meeting in Gunnison on Monday, April 26.