Snowpack beating norm by more than a third

Arkansas River Basin is 11 percentage points below normal

Colorado’s mountain snowpack heading into spring on Wednesday measured at 136% of the 30-year norm — an indicator that water supplies could swell depending on the overall drought, soil moisture, melting rates and future precipitation.

“The snowpack has yet to run off,” said Brian Domonkos, supervisor of the federal government’s Colorado Snow Survey.

March snowstorms buffeting mountains in western Colorado built up already hefty snowpack, particularly along headwaters of the Colorado River, according to the latest federal survey data. But the Arkansas River Basin — crucial for agriculture on the plains of southeastern Colorado — lagged with mountain snowpack measuring 89% of the 1991-2020 norm, data from the U.S. Department of Agriculture’s Natural Resources Conservation Service show.

For the most-populated areas around metro Denver and farms and ranches in northeastern Colorado, the South Platte River Basin snowpack measured 103% of the norm.

The closely-watched Upper Colorado River Basin had snowpack at 127%.

Southwestern Colorado mountains, relatively dry in recent years, had exceptionally high snowpack — 167% of the norm in the combined San Miguel, Dolores, Animas and San Juan river basins, the data show.

Along the upper Rio Grande River in southern Colorado, snowpack increased over the past two weeks to 125% of the norm. The Gunnison River Basin had snowpack at 156%; the Yampa and White rivers at 142%; and the Laramie and North Platte rivers at 124%.

Water supply storage reservoirs around Colorado, on average, were about 77% full, according to the latest federal data.