Snowpack/runoff news: Another day, another increase in the statewide snowpack as a percent of average

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Here’s the May 1 release from Mike Gillespie and the Natural Resources Conservation Service:

Snowfall across northern Colorado during April was one for the record books. The latest snowpack measurements, conducted by the USDA – Natural Resources Conservation Service (NRCS), show record levels of snowpack at many measuring sites throughout the Yampa, Colorado, and North and South Platte basins in Colorado.

Of particular interest is a new all-time record snowpack at the Tower SNOTEL site which, on average, receives the greatest snowfall of any location in the state measured by the NRCS. This site, located on Buffalo Pass in the Park Range northeast of Steamboat Springs, reached a total accumulation for this season over 200 inches deep, with 72.6 inches of water content. This exceeds the previous record reading of 71.1 inches of water equivalent measured in 1978, according to Allen Green, State Conservationist with the NRCS. This sets an all-time state record for total snowpack at any individual site in Colorado.

Other sites across the northern tier of the state saw long-time records fall. For example the snow course on Cameron Pass, west of Fort Collins, shattered the old record this month with 48.0 inches of water content. The old record was measured back in 1971 with 42.5 inches of water. This site has been measured since 1936 and is one of the oldest snow course sites in the state.

“Even many of the old-timers have never seen some of the depths measured across northern Colorado this month”, said Green.

While northern Colorado has received abundant snowfall this year, it’s a completely different story across the southern portion of the state. Snowfall during April was below average once again this month, continuing the trend set since January.

The latest surveys indicate the lowest snowpack percentage in the state was measured in the Rio Grande Basin at only 72% of average. While snowpack percentages in the combined San Juan, Animas, Dolores and San Miguel basins of southwestern Colorado improved slightly during April, those basins remain below average.

For most of the state, this spring’s runoff and summer water supplies will be excellent. With the exception of the Rio Grande, and those basins in southwestern Colorado, runoff volumes for the April through July period are expected to range from slightly above average to near record volumes. The basins that can expect some of the largest volumes include the Yampa, North Platte and along the Cache La Poudre River in the South Platte Basin.

Current reservoir storage remains in good condition across most of the state. Only the Rio Grande and Arkansas basins are reporting below average storage as the state enters the snowmelt season. The only anticipated water shortages this year are expected in the Rio Grande basin where below average runoff has combined with below average reservoir storage. Elsewhere across the state, water supplies should be the best in over a decade.

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Yesterday morning the statewide snowpack stood at 144% of average, this morning it’s at 146%. Look at the Yampa/White basins — 170%! The hope is for a slow melt out to minimize flooding. It’s going to be a great year for storage. Here’s a report from Chris Woodka writing for The Pueblo Chieftain. From the article:

The snow in the mountains will help bring relief to the Arkansas Valley, which has been gripped by drought since last August. After Sunday’s storm, even the Sangre de Cristo, Wet Mountains and Spanish Peaks were coated in white after being bare for weeks.

For the northern part of the state, the snow is old news by now. At Buffalo Pass near Steamboat Springs, the snowpack measured 16 feet on Tuesday, with a snow water equivalent of 72.6 inches — the highest amount since record-keeping began in the 1930s, said Mike Gillespie, state snowpack coordinator for the Natural Resources Conservation Service. Cameron Pass, a site near Fort Collins in the South Platte River basin, is showing snow water of 48 inches, which eclipses the record of 40.9 inches set in 1986…

For the past decade, spring runoff has been coming about two weeks sooner than historically recorded. But this year, the peak snowpack has yet to arrive in most of the northern mountains — and usually, that occurs in mid-April…

The Bureau of Reclamation is projecting 94,200 acre-feet of imports based on a snowpack of 181 percent of average in the Fryingpan-Arkansas collection area in the upper Roaring Fork basin. “There’s some concern it will melt too quickly to capture it all,” said Linda Hopkins of the Pueblo Reclamation office…

There is reason to be cautious, however. In 2008, 100,000 acre-feet of runoff was projected in early May, but only 90,000 acre-feet came through the Boustead Tunnel because of the way the snow melted. Reclamation has been releasing additional water from Turquoise and Twin Lakes to make room for the Fry-Ark water, and storage in Lake Pueblo is not an issue at this time…

Flows in the Arkansas River are below average for this time of year, reflecting the slow runoff. For the past decade, runoff has begun about two weeks earlier than normal, and reached multiple peaks in several years as temperatures rose and fell.

From The Aspen Times (Scott Condon):

The snowpack at the agency’s Independence Pass site as of May 1 was the third highest for that date in the last 74 years, according to research by Mike Gillespie, snow survey supervisor. Records for the site go back to 1937. The water content in the snowpack at the Independence Pass site was 24.8 inches on Sunday, Gillespie said. That level was topped only by readings for that date in 1947 and 1957, he said. In more recent times, the snowpack at Independence came close to this year’s level in 1995 when the water content was 24.20 inches. The snowpack at Independence Pass was 159 percent of average for May 1, the agency reported…

Elsewhere in the basin, the snowpack was 223 percent of average at Nast Lake; 187 percent of average at Kiln; and 161 percent of average at Ivanhoe. All of those sites are in the Fryingpan Valley, between 8,700 feet and 10,400 feet in elevation. In the Crystal Valley, the snowpack was 204 percent of average at North Lost Trail near Marble; 168 percent of average at McClure Pass; and 142 percent of average at Schofield Pass. Those sites range from 9,200 to 10,700 feet in elevation. Basin-wide, the snowpack was 164 percent of average, the NRCS reported…

“Of particular interest is a new all-time record snowpack at the Tower SNOTEL site which, on average, receives the greatest snowfall of any location in the state measured by the NRCS,” the agency said in a press release. “This site, located on Buffalo Pass in the Park Range northeast of Steamboat Springs, reached a total accumulation for this season over 200 inches deep, with 72.6 inches of water content. This exceeds the previous record reading of 71.1 inches of water equivalent measured in 1978.”[…]

“For most of the state, this spring’s runoff and summer water supplies will be excellent,” the NRCS said. With the exception of the Rio Grande basin and areas in the southwest, “runoff volumes for the April through July period are expected to range from slightly above average to near record levels,” the agency said.

From the Longmont Times-Call:

Buffalo Pass in the Park Range northeast of Steamboat Springs, reached a total accumulation for this season over 200 inches deep, with 72.6 inches of water content. This exceeds the previous record reading of 71.1 inches of water equivalent measured in 1978, according to Allen Green, State Conservationist with the NRCS.

From the Summit County Citizens Voice (Bob Berwyn):

Rather than worrying having enough, the big concern this year is for the potential of flooding in many local river basins, including the Upper Blue between Hoosier Pass and Breckenridge. where Colorado Springs usually diverts up to 150 cubic feet per second of water through a pipeline under the Continental Divide. This year, Colorado Springs is working on a rehabilitation project on Montgomery Reservoir, said project engineer Kalsoun Abbasi, explaining that, at the most, Colorado Springs will only be able to divert one-tenth of that amount.

There’s also potential for high water below Dillon Reservoir in the Blue River, said Steger, Denver Water’s raw water supply manager. Much will depend on exactly how fast and when the peak snowmelt occurs. The snowpack across the Blue River Basin is more than 150 percent of normal, with the Copper Mountain SNOTEL site recording its highest reading ever, dating back to the late 1970s. “We’ve got serious concerns about flooding below the dam,” said Denver Water manager Jim Lochhead, sitting in a panel discussion with Summit County officials…

Green Mountain Reservoir will also fill sometime in June, said Ron Thomasson, who manages the reservoir for the federal Bureau of Reclamation, predicting the Blue River below Green Mountain Dam could run at levels not seen sice 1995, another big snow year.

From the Associated Press via The Durango Herald:

The U.S. Department of Agriculture’s Natural Resources Conservation Service measured snowpack in Poudre Canyon that reached more than 160 inches, or almost 13.5 feet, at one point, according to a story in The Greeley Tribune. Officials said the snow was almost too deep to measure in some places…Weld County officials worry about the melting snow’s effect on the Poudre River. They say the river could flow at 6,000 cubic feet per second, or 1,700 cfs more than last spring. Crews are removing debris to prevent log jams when the streamflow increases.

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