Statewide snowpack now just 19 percent of average; summer streamflows expected to be less than 50 percent of average
By Bob Berwyn
SUMMIT COUNTY — The snowpack and runoff news keeps getting worse and worse in Colorado, as April brought another big drop in the numbers. The downward trend doesn’t bode well for the summer, and while reservoir storage is currently just above average statewide, those levels will quickly drop when irrigation season begins.
In Summit County measurements at Hoosier Pass by the Center for Snow and Avalanche Studies show that, at times, the snowpack was melting at a rate of an inch per day, accelerated by a layer of dark-colored dust that reduced the snow’s albedo.
“Statewide snowpack looks to have peaked around March 12, a month ahead of the average peak date, and began melting in late March at rates typically not observed until May,” said Phyllis Ann Philipps, State Conservationist with the Natural Resources Conservation Service.
In some parts of the Upper Colorado, stream are flowing at October levels at a time when they should be cresting toward peak flows. For the summer, most streams are expected to flow at less than 50 percent of average.
The latest snow surveys show that most low and mid elevation measurement locations have little or no snow and the higher elevation sites are well below average and rapidly melting. The May 1 statewide snowpack report reflects this, measuring just 19 percent of average. For the second month in row statewide snowpack conditions match those recorded during the record-setting drought year of 2002.
The largest losses in snowpack percentage were measured in the Gunnison and the Upper Rio Grande basins; both reported drops of 38 percent from April 1 to May 1. The Upper Rio Grande basin now has the lowest snowpack percentage in the state, at just 15 percent of average as of May 1.
The combined Yampa and White basins, while no longer the lowest in the state, are not far behind at 17 percent of average. The North Platte basin, still a dismal 27 percent of average, has the highest basin wide snowpack in the state. Snowpack reports in the other major basins range from 18 to 25 percent of average.
In an average year, the snowpack in Colorado continues to accumulate during the first half of April and then slowly begins to melt during the second half of the month. This year by April 1 the shallow snowpack had already advanced well into the melt season and melt continued progressing 4 to 6 weeks earlier than normal throughout the rest of the month. As of May 1, 55 percent of the snow survey locations throughout Colorado reported no snow.
The state’s reservoir storage continues to provide a glimpse of hope this year, with total storage volumes across the state remaining above average. This stored water may help alleviate conditions early in the season; however water users should be aware of the potential for late season shortages