Luke Runyon (KUNC) brings us up to date on the current state of winter snowpack storage in the Colorado River Basin. Here’s an excerpt:
The first official forecast for the amount of water expected in the Colorado River and its Rocky Mountain tributaries this spring is in, and the outlook is grim.
“Well, it’s not looking really great at this point,” says Greg Smith, a senior hydrologist at the National Oceanic and Atmospheric Administration’s Colorado Basin River Forecast Center in Salt Lake City, Utah.
Layers of snow in the Colorado, Wyoming and Utah mountains feed the Colorado River basin. Some regions are reporting the driest start to a winter ever recorded. All of the river’s upper basin streams empty into Lake Powell, a reservoir on the Utah-Arizona border. The lake’s inflow — all water entering the reservoir — is anticipated to be 55 percent of average during spring runoff.
Snowpack in Colorado is currently less than half of what it is in an average year.
“The forecasts have dropped off quite dramatically,” Smith says. “We have several areas where we’re forecasting less than 50 percent of average.”
That means some major streams could have less than half their normal flow from April to July. Low snowpack and low soil moisture in Colorado’s Gunnison, Dolores and San Juan river basins are causing forecasts to dip into the 30 to 60 percent of average range.
Portions of Colorado, Utah, Arizona and New Mexico are experiencing moderate to severe drought, according to the most recent U.S. Drought Monitor. Almost the entirety of the watershed is in some form of short-term and long-term drought.
Coming off a couple years of average to above average snowpack in the Rocky Mountains, many of the region’s reservoirs have the capacity to withstand a dry year. But Smith says some of the smaller reservoirs’ managers are beginning to sweat the low snowpack.
Here’s a deep dive into snowpack history in Aspen from Scott Condon writing for The Aspen Times. Here’s an excerpt:
The city of Aspen water plant recorded 9 inches of snow in November and 6 inches in December 1976. That’s just 15 inches to start the season.
This year, 6.8 inches was recorded in November and 13 inches in December, according to water plant data released Wednesday. That’s 19.8 inches to start the winter.
That’s not unheard of in Aspen. In 1943 only 22.3 inches fell in November and December. In 1954 the figure was 20.5 inches.
More recently, another drought hit in 1980 when 22 inches fell in November and December.
From the Associated Press via The Denver Post:
Rocky Mountains snowpack that feeds Colorado River water supplies was 20 percent below average in December in some areas, prompting a prediction that the key water source for seven U.S. states could flow at 54 percent of its average volume during the April-July snowpack runoff period.
On Thursday, snowpack in the Upper Colorado Basin was reported at 65 percent of normal…
Lake Mead’s surface has dropped more than 130 feet since drought descended on the Colorado in 2000. But the lake that sits upstream from Hoover Dam east of Las Vegas ended 2017 almost 2 feet higher than a year ago, as use of Colorado River water by Nevada, Arizona and California hit its lowest level since 1992.
According to preliminary accounting figures from the U.S. Bureau of Reclamation, those three states consumed a combined 6.7 million acre-feet from the river last year, driven by wet conditions in California and widening efforts to curb use in Arizona.
That left enough water in Lake Mead to keep it more than 7 feet above the trigger point for a federal shortage declaration, which would mean mandatory cuts for river users in Nevada and Arizona.
The federal projections released last month called for Lake Mead to finish 2018 roughly 4 feet lower than it is now but still safely out of shortage territory. In light of Wednesday’s river forecast, the projections for the lake are almost certain to get worse.