Scott Condon
The Aspen Times

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February 4, 2014
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Scientists get a grip on snowpack

Scientists are seeking a more accurate way to measure snowpack levels to provide water managers — like those at Ruedi Reservoir — with better tools to gauge spring runoff.

Currently, there are automated Snotel sites planted around the mountains. They provide the picture at given locations, but cannot account for factors such as wind loading of snow in parts of drainages away from the measurement sites. The sites also examine snowpack at a specific elevation. The vast majority of Snotel sites in Colorado are below tree line.

In the Roaring Fork River basin, there is only one measurement site for the entire upper Roaring Fork headwaters, east of Aspen. There are three measurement stations in the Fryingpan Valley and three in the Crystal Valley.

The snowpack for the Roaring Fork River basin as a whole is 118 percent of average. However, that ranges from a high of 145 percent of average at the Ivanhoe site at 10,400 feet in the Fryingpan Valley to 97 percent at North Lost Trail near Marble. The snowpack at the Independence Pass site is 123 percent of average. That site is actually on Lincoln Creek above Grizzly Reservoir at an elevation of 10,600 feet.

Scientists at the NASA Jet Propulsion Laboratory and University of Colorado research scientist Jeffrey Deems are using laser mapping in two demonstration projects in California and Colorado to expand snowpack data.

Deems will make two presentations in the Roaring Fork Valley this week to discuss the laser mapping. He is the featured speaker at the Naturalist Series presented by Aspen Center for Environmental Studies, Wilderness Workshop and Roaring Fork Audubon.

Deems will speak at 5:30 p.m. Wednesday at the Third Street Center in Carbondale and at 7 p.m. Thursday at ACES headquarters at Hallam Lake. The presentations are free.

Deems said in a telephone interview from Boulder on Tuesday that measurements were taken of the land height before the snow started flying. That provided the baseline data. Now, regular flights are being flown over the drainages, and laser mapping measures the height of the snow surface. That gives scientists good data on snow depth and allows estimates of water content.

The wealth of information is shared with water managers so they can determine if they need to let more water out of reservoirs because of high anticipated runoff or if they need to reduce flows because there is a small snowpack, Deems said.

In addition to the snow depths, the laser mapping measures snowpack reflectivity. “If there’s dust, we saw that,” Deems said.

Dust on the snowpack can lead to quicker melting because the darker dust absorbs the sun.

The laser mapping is being used in a drainage in Yosemite National Park that feeds a reservoir that supplies much of San Francisco’s water. The other demonstration project is in the Uncompahgre Plateau area of Colorado. The use of laser mapping will come down to funds available for the flights, Deems said.

He stressed the technique is meant to complement rather than replace the Snotel sites, which are operated by the Natural Resources Conservation Service.

“We’re far from trying to put the NRCS out of business,” he said.

Deems said his presentations about the program will be understandable for laymen. “Other than lasers are super cool, probably the most interesting thing is it’s a window into the natural world that we don’t see on this scale,” he said.

scondon@aspentimes.com


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The Post Independent Updated Feb 4, 2014 11:04PM Published Feb 4, 2014 11:04PM Copyright 2014 The Post Independent. All rights reserved. This material may not be published, broadcast, rewritten or redistributed.