Warm, dry May adds to Aspen’s low snowpack woes
Aspen received less than half of its normal precipitation in May and followed the statewide pattern for a rapidly disappearing snowpack.
The Aspen Water Plant recorded 0.77 inches of precipitation for the month. The average for May is 1.9 inches, according the water plant’s report.
Rain or snow was recorded on only four days the entire month, the report showed. It was the driest May since the drought year of 2002 when only 0.21 inches of precipitation was recorded — the record low for the month since 1951 — when the water plant started tracking weather. The wettest May came in 1995 when 5.41 inches of rain and snow was recorded.
Aspen wasn’t alone in dry conditions. Precipitation statewide was only 55 percent of normal, according to the Natural Resources Conservation Service.
Dry conditions around the state led to the snowpack melting earlier than normal, according to the conservation service, which monitors automated snowpack measuring stations throughout the mountains.
The statewide snowpack was 24 percent of normal on June 1. That’s good for hikers, bikers and other recreation groups, but not so good for irrigators, the federal agency said.
“While these conditions are more favorable for hiking Colorado’s mountains, snowpack and precipitation shortages in May further depleted Colorado’s summer water supply outlook,” said Brian Domonkos, Colorado Snow Survey supervisor and a hydrologist with the conservation service.
In a normal year, 21 of the 115 automated snow telemetry sites in Colorado show at least an inch of snow water equivalent on June 1. This year only 10 sites showed any measurable snowpack.
The snowpack in many parts of the state was the worst since 2002, the worst winter on record at the automated snow measuring stations, according to the conservation service. In some locations in southwest Colorado, it was worse than 2002.
Many streams that typically peak in June peaked in May this year, two to three weeks early, the conservation service said in a report released Friday.
Domonkos said the streamflow outlook for the Roaring Fork River at Glenwood Springs indicates the total volume of water moved between June 1 and July 31 will be 38 percent of normal under the most probable scenario.
“That gives a good indication of what we’re seeing” with snowpack at the headwaters, he said.
Some water-measuring gauges on the Gunnison River and in the Rio Grande watershed in the southwest part of Colorado are forecasted to have record lows. Overall, streamflow forecasts are between 50 and 85 percent of normal.
Basalt-based Roaring Fork Conservancy noted in its report Friday that most of the Roaring Fork watershed is in moderate drought.
“The comparison to average flow is striking right now because typically at this time of year the water is still rising toward peak flow,” the conservancy reported. “This year, rivers have already peaked and are rapidly dropping to lower summer flows.”
The Roaring Fork River near Aspen is flowing at 152 cubic feet per second compared with an average flow of 425 cfs at this time of year.
Domonkos noted that statewide reservoir storage is about 106 percent of average. That is starting to drop as water is called for irrigation to supplement receding runoff.