Upper Colorado River Basin snowpack second lowest since 1992
March 11, 2010
As a result of decent storm activity during the third weekend of February, snowpacks in the Upper Colorado River Basin improved slightly from 72 percent of average last month to 79 percent of average on March 1.
This is the second lowest March 1 snowpack percentage the basin has seen going all the way back to 1992. Only March 1, 2002, with 68 percent of average snowpacks, was lower.
Using projections based on historical SNOTEL data, there is only a 10 percent chance that the basin will reach its average peak snowpack. Most of the sub-basin snowpacks are below average to well below average.
The lowest snowpack percentages can be found in the Willow Creek and Muddy Creek watersheds at 59 percent and 69 percent of average, respectively (these are lower than 2002). The Roaring Fork and Plateau Creek drainages boasted the best snowpacks at 90 and 95 percent of average. February precipitation at the higher elevations was 95 percent of average.
This is the fourth month in a row that monthly precipitation has been below average. Total precipitation for the water year remains below normal at 82 percent of average.
Reservoir storage is 109 percent of average and 110 percent of last year’s storage at this time. Streamflow forecasts either remain unchanged or dropped as much as 4 percentage points from those issued a month ago.
The basin can expect below-average runoff during the April-July forecast period at almost all the forecast points, ranging from 55 percent of average for the Inflow to Willow Creek Reservoir to 85 percent of average for the Roaring Fork at Glenwood Springs.