Snowpack is beating 30year norm as spring nears
Colorado mountain snowpack measured above normal in early March, a few weeks before the closely watched seasonal peak, except in the Arkansas River Basin, where lagging snow could lead to low water flows.
The snowpack tracked by federal snow surveyors appeared relatively promising with the latest data showing the overall statewide level at 120% of the norm, which is based on a 30year average between 1991 and 2020. In particular, watersheds that feed the heavily-tapped Colorado River held above-average snow, according to the U.S. Department of Agriculture Natural Resources Conservation Service snow survey data.
“We still have a little bit more of winter to go, and then we will have the early spring and early summer precipitation that could still give us a boost. If we do get a good spring, things could get better,” snow survey supervisor Brian Domonkos said.
“But things could go the other way, too.”
Snow on Colorado’s mountains typically peaks between March and mid-april and serves as a natural, slow-release source of water — essential to sustain urban settlement and agriculture in the West. Around April 1, Colorado Front Range cities and food growers on the eastern plains traditionally have calculated whether water supplies through summer will be sufficient for people, crops and cattle based on mountain snow.
Agriculture uses about 85% of Colorado’s water supply. Urban water consumption per person has been decreasing, though the state’s overall population has been increasing at faster than the national rate.
Denver Water utility officials last week measured water storage in their reservoirs at 82% — above average for early March. The utility officials also noted, in an agency website posting, that soil in the watersheds where Denver draws water isn’t as dry as last year. Long-term droughts can leave soil so dry that it quickly absorbs water from melting snow before the water reaches streams and rivers.
Climate warming has been shrinking mountain snowpack and reducing runoff into streams. Atmospheric scientists have projected a sharply reduced contribution of melting snow in
the Colorado River Basin, a main source for 40 million people and agriculture producers across seven states including California.
Around Colorado, snowpack in the Colorado River Basin measured 118% of the norm, the federal data show.
Southwestern Colorado had the most snow with levels in the combined San Miguel, Dolores, Animas and San Juan river basins at 138% of normal.
The South Platte River watershed — crucial for cities, including Denver, and food producers in the most populated parts of northeastern Colorado — had 103% of normal snowpack.
Along the upper Rio Grande River in southern Colorado, snowpack measured 107% of the norm. The Gunnison River Basin had snow at 136% of the norm, the Yampa and White rivers 133%, and the Laramie and North Platte rivers 120%.
But the Arkansas River Basin snowpack measured 73% of the norm, the data show.
From headwaters above Buena Vista and Salida to the southeastern plains out to Kansas, cities, towns, farmers and ranchers rely on Arkansas River water flows through the summer.