LAKEWOOD- February’s weather brought only slight increases to the snowpack percentages across most of Colorado, according to recent snowpack surveys conducted by the USDA-Natural Resources Conservation Service (NRCS). The latest data indicates that the statewide snowpack increased to 88 percent of average, up from the 86 percent of average recorded on February 1. This year’s snowpack continues to lag well behind last year’s at this time, with the March 1 readings only 82 percent of last year’s totals on this date, according to Allen Green, State Conservationist with the NRCS.
Another trend in this year’s snowpack pack data is the variability across the state that has been driven by the 2010 El Niño storm track which has favored the southwestern US. This pattern has resulted in those basins across southern Colorado tracking at near to slightly above average snowpack totals, while those basins in central and northern Colorado remain well below average. At this time, only two basins in the state are tracking at above average levels. Those include the Rio Grande, at 109 percent of average, and the combined San Juan, Animas, Dolores, and San Miguel at 106 percent of average. Other nearby basins, which are tracking at just slightly below average, include the Gunnison and the Arkansas, both at 95 percent of average. Across northern Colorado, snowpack percentages remain well below average, having not tracked at these percentages since the drought year of 2002. Those basins include the Colorado, Yampa and White, and the North Platte. These basins, along with the South Platte, range from 72 to 79 percent of average.
Given the low snowpack percentages across northern Colorado, the probability of improving to near average by the end of the winter snowpack accumulation season in mid-April has dwindled to less than a 10 percent chance. “Water users in these basins should be prepared for significantly less water than in the previous two years”, said Green. The remaining wild card in this year’s water supply picture is how this year’s El Niño weather pattern will affect the state’s spring precipitation patterns. “It’s the one thing that could still help improve the current outlook even in those dry basins in the north”, said Green.
Snowfall during the next six weeks will be critical in determining how this spring and summers water supplies will fare. As of March 1, the state’s water supply forecasts fairly closely mirrored the state’s snowpack percentages. Those basins across southern Colorado are expected to see near average to slightly above average runoff volumes this year. Meanwhile, well below average runoff is expected in the Colorado, Yampa, White, and North and South Platte basins.
Fortunately for most water users, the past couple of good runoff years have helped to keep reservoir storage in near average condition across most of the state. This available stored water may help alleviate late-summer shortages in some basins.