Normal mountain snowfall in February keeps water outlook bright
March 9, 2017
Snowpack and reservoir storage
Basin % of median % of last year % of average reservoir storage % of average storage last year
Gunnison 155 155 110 109
Colorado 135 135 107 110
South Platte 140 138 107 107
North Platte 130 142 — —
Yampa/White 116 120 127 122
Arkansas 143 140 103 124
Rio Grande 136 137 91 93
SMDASJ* 149 153 114 104
Statewide 139 140 107 111
* Combined San Miguel, Dolores, Animas and San Juan basins
After two unusually wet months in December and January, normal mountain snowfall returned to Colorado in February, leaving snowpack totals across the state well above normal.
"Statewide, year-to-date precipitation now stands at 123 percent of normal on March 1, while snowpack is a robust 139 percent of normal," Colorado Snow Survey Supervisor Brian Domonkos said this week in a news release.
Mountain snowfall melts in the warmer months and provides much of Weld County's water. In the two basins that affect Weld, snowpack totals also were above normal. In the Colorado River basin, snowpack was 135 percent of normal on March 1, and in the South Platte River basin, it was 140 percent of normal.
"All but two of the major basins in Colorado have already surpassed average annual peak snowpack," Domonkos said.
Those two basins are the South Platte and the combined Yampa and White basins.
Statewide reservoir storage is slightly above normal, 107 percent of average, heading into what streamflow forecasts indicate will be an above-normal runoff year in most watersheds. With nearly all runoff projections pointing toward above-normal streamflows, many locations likely will see adequate water supplies, the release stated.
Reservoir storage in the South Platte and Colorado basins was at 107 percent of average.
Despite the wet months and favorable outlook, experts expressed caution, noting sufficient time remains in the snowy season — which typically lasts through April — to significantly change things. From dry, warm and windy weather to cool and rainy or snowy, future weather still can affect runoff even in years of surplus snowpack.
Colorado's water year, which began Oct. 1, got off to a slow start. What little precipitation fell came in the form of rain, and warm autumn temperatures prevented snow from accumulating in all but the highest elevations. From the beginning of the water year through Nov. 17, statewide snowpack was off to its worst start in more than 30 years at 6 percent of average, according to a news release from the conservation service.
As temperatures cooled in the late fall and early winter, however, snow began to accumulate in the mountains. The unusually wet December and January boosted the snowpack and brightened the state's water outlook.