Summit County Citizens Voice

Snowpack in the southern mountains is near average, in the north, levels lower than they've been since the 2002 drought.

Below-average runoff expected in Colorado River Basin, but El Niño still a wild card, forecasters say

By Bob Berwyn

SUMMIT COUNTY — Colorado’s statewide snowpack inched upward about 2 percent from February, thanks to a series of storms that finally delivered widespread snow to the northern and southern mountains.

But in the northern mountains, snowpack was tracking near levels not seen since the historic 2002 drought. Unless big spring storms roll in, water users need to prepare for less supplies than in the past few years, said federal officials who monitor water supplies.

Snowpack in the Colorado, Yampa and White, and the North Platte basins, along with the South Platte, ranges 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.

The latest data show 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.

“Water users in )northern Colorado) 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, he added.

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.

Filed under: rivers, Summit County Colorado Tagged: | 2010 runoff forecasts, Colorado River Basin, Colorado snowpack, Colorado water supplies, Summit County Colorado, Summit County News