Dust speeding up runoff in Colorado streams, rivers
CARBONDALE, Colo. (AP)--Colorado's rivers and streams could reach peak runoff 20 to 30 days earlier than average this year, and dust storms are the reason.
Andy Barrett of the National Snow and Ice Data Center in Boulder said the dust was deposited by 12 storms between mid-December and early April.
Dust-covered snow melts faster because its darker surface absorbs more of the sun's heat than cleaner snow does. Clean snow typically reflects 90 to 100 percent of the sunlight.
Mike Gillespie, snow survey supervisor for the U.S. Department of Agriculture's Natural Resources Conservation Service, said the result of quickly melting snow will be a condensed runoff season. Flows will be high early and recede sooner.
"That's good news if you're a fly fisherman and you want to get out there sooner," Mike Gillespie said. "It's not such great news for the rafting industry or water users.
Earlier peak flows could mean less water will be available for irrigation systems tied to streams and rivers later in the summer when farmers need it, though that's not expected to happen.
"The same amount of water will flow into the reservoirs; it will just come sooner," Gillespie said.
An intense dust storm speeded up the melting of the snowpack by about 30 days in the spring of 2006.
Tom Turnbull, who has ranched at the base of Mount Sopris for 40 years, said he has seen dust on the mountains before but probably never to the current degree. He said the uniformity of the dust sticks out this season, too.
Chris Landry, director of the Center for Snow and Avalanche Studies in Silverton, said the dust layers laid by the different storms are consolidating as the snow melts.
"That dirt layer stays at the surface. It doesn't wash away with the snowmelt," Landry said. "It just keeps churning its way downward."
Melting snow contributes about 80 percent of the water in rivers, streams, lakes and reservoirs, which comprise much of the state's water supply. Colorado's eight river systems also provide water to 10 western states.