In a winter when a normal amount of snowfall in Colorado won’t be enough to adequately counter the effects of ongoing drought, snowpack accumulations so far are heading in the wrong direction, currently at about three-quarters of normal.
Statewide snowpack was at 74% of median Thursday, with percentages even lower in area basins, at 68% for the Gunnison River Basin and 70% for the Upper Colorado River Basin, according to Natural Resources Conservation Service data.
Local conditions are worse, with measurements ranging from 46 to 57% at NRCS Grand Mesa snowpack-measuring sites, and at 66% for the Plateau Creek drainage.
While conditions can change, the NRCS said in a Jan. 1 water supply outlook report for Colorado that current streamflow forecasts during the snowpack runoff season “for April through July range from a high of 98% of average for the Cucharas River near La Veta, to a low of 42% of average for Surface Creek at Cedaredge.”
It said streamflow volumes for the combined Yampa, White, the Upper Colorado, the Gunnison, and the combined San Migue, Dolores, Animas, San Juan river basins “are all forecasted to be within 64 to 68% of average, with some variability within each basin.”
The lagging snowpack accumulations so far in Colorado come as the entire state currently is in a drought. Most of western Colorado is in either exceptional drought, the worst category, or extreme drought, the second-worst category, according to the U.S. Drought Monitor. Much of Mesa County is in exceptional drought, with the northwest part of the county in extreme drought.
According to an NRCS news release, Colorado precipitation in August and September combined totaled the lowest in a 36-year period of record at its measurement sites, and October precipitation was less than half of average.
The National Oceanic and Atmospheric Administration last week reported that combined average annual precipitation last year in Colorado, Arizona, Wyoming, Utah and New Mexico was the second-lowest on record and the lowest since 1956. It said dry conditions are expected to continue for the Southwest.
Parched soils and declining reservoir storage are heightening the importance of Colorado getting good snowpack volumes this winter.
“Dry soils will play a meaningful part in the upcoming runoff season as the ground will absorb much of the first pulse of meltwater during snowmelt. As such, it will take an above-average snow accumulation in many basins to produce average runoff,” NRCS said in its water supply outlook report for Colorado. “… As the season evolves anything less than above average snowfall will produce below average streamflow volumes come April in most parts of the state.”
NRCS said in its news release that near-normal snowpack and reservoir storage leading into last spring helped Colorado stave off significant runoff shortages last year. But current reservoir storage is below normal for this time of year across the state, at 82% of average as of the start of the new year.
Reservoir storage in the Gunnison River Basin is currently at 77% of average, compared to 104% average for Jan. 1 at the same time last year. Blue Mesa Reservoir, Colorado’s largest reservoir, is currently less than half full.
Storage in the Upper Colorado River Basin is much higher than the statewide average, at 102% of normal for this time of year. Currently the Rio Grande Basin, which in recent years has been quite dry, is doing the best across the state in terms of snowpack, at 95% of median. The Arkansas River Basin ranks second-highest, at 93%.
The National Weather Service Climate Prediction Center currently shows equal chances of above- or below-average precipitation in Colorado over the next 30 days, and below-average chances in all but far-northwestern Colorado over the next three months.
Still, Brian Domonkos, supervisor of the NRCS Snow Survey Program in Colorado, remains optimistic, according to the NRCS news release.
“With slightly more than half of the snowpack accumulation season remaining there is potential for snowpack to improve,” he said in the release.