From The Durango Telegraph (Will Sands):
Scientists have long known that dust was changing the reflective properties of snowfields and increasing the speed of runoff each year. However, this study is the first to measure the full impact of dust storms on snowmelt rates and basin runoff. The team examined run-off in the Upper Colorado River basin between 1915-2003 and then simulated conditions prior to the settlement of the region in the mid-1800s. Lake sediment cores show that dust deposits in the San Juan Mountains increased by between 500 and 600 percent since the Southwest was settled. Based on these values, the team discovered that the Colorado River basin is experiencing a 35-billion cubic foot reduction in water every year because of dust. That amounts to enough water to supply the City of Los Angeles for 18 months. “Actions to stabilize soils and minimize activities that disturb soils could potentially decrease dust emissions and the loss of runoff,” argued Tom Painter, the team leader and a snow hydrologist with NASA.
Ronni Egan, executive director of the Durango-based Great Old Broads for Wilderness, said residents of the Southwest should be taken aback by the numbers.