Here’s the release from the NRCS Colorado (Brian Domonkos):
Several low-pressure systems moved across the state bringing heavy snow accumulations to the eastern slopes of the Colorado Rockies during March. Precipitation in March ranged from a high of 126 percent of average in the South Platte River Basin to as low of 86 percent of average in the combined Yampa-White-North Platte River Basins. NRCS Hydrologist Joel Atwood notes, “Generally storms in March improved snowpack across the state with the greatest gains in eastern river basins. Despite these storms, warmer temperature in the mountains have already begun melting the snowpack.” Snowpack as of April 8th ranges from a low of 71 percent of median in the combined San Miguel-Dolores-Animas-San Juan river basin to a high of 92 percent of median in the South Platte River Basin.
Statewide reservoir storage only increased by a percentage point over last month. Currently, the only river basin in the state holding above average reservoir storage is the combined Yampa-White river basins. On the low end, the combined San Miguel-Dolores-Animas-San Juan and the Arkansas river basins have 59 and 69 percent of average reservoir storage, respectively.
A drought that was well in place as the snowpack began to accumulate has had little relief with recent precipitation as all basins in the state continue to maintain below average water year-to-date precipitation. Before the water year, an exceptionally warm and dry summer and fall has resulted in extremely dry soils. NRCS Hydrologist Atwood continued to comment that “A combination of dry soils and below normal water year-to-date precipitation will likely moderate the runoff produced from snowmelt, producing lower volumes than would commonly be observed with a similar snowpack.”
The lowest streamflow forecasts in the state are rivers draining the Southern San Juan Mountains and the Gunnison River Basin. The average streamflow volume forecasts in these basins range from 36 to 77 percent of average. With recent storms, the Arkansas River Basin now has the best water supply outlook in the state, where streamflow volume forecasts range from 83 to 109 percent of average.
* For more detailed information about April 1 mountain snowpack refer to the April 1, 2021 Colorado Water Supply Outlook Report. For the most up to date information about Colorado snowpack and water supply related information, refer to the Colorado Snow Survey website.