Colorado River levels mostly unaffected by lastest snowstorm
May 21, 2017
The snowstorm that pummeled Summit County and parts of the Front Range late last week may have been exceptional for powder junkies still hanging onto the last semblance of ski season, but it's unlikely to move the needle substantially on this summer's water levels.
Arapahoe Basin Ski Area — the last resort still open in the state — reported more than 22 inches of snow over a four-day period to end the week, with the bulk falling very early Wednesday into Thursday and then most of the day Thursday into Friday. That total brings May's snowfall in the area up to 24.5 inches, just the fifth time it has hit 24 inches or more since the start of the 20th century.
It's the liquid-equivalent within the snow that matters most for water experts, however, and that remains difficult to determine until it eventually melts and can be properly measured. Even if historically this storm was a bit larger than those that typically descend upon the region in the spring, it is still not expected to represent more than 3 percent of the total moisture for the year.
"The runoff forecast doesn't look at snow, it looks at total precipitation and the water content of the snow," said Eric Kuhn, general manager of the Colorado River District. "Snowpack doesn't tell you much, because cold weather can slow it and if it's warmer it can accelerate it. It is a boost … but it could still end up average (levels) with this storm, it just depends on what happens in the next 10 days."
This upcoming week's forecast calls for occasional precipitation Monday, Thursday and possibly Friday, as well as early next week. The temperatures will be cooler, OpenSnow.com meteorologist Joel Gratz wrote in an email, creating chances for snow at higher elevations, but another storm the size of the most recent one doesn't appear in the cards. Additional rain, though, will of course contribute to area streamflows.
Still, the approaching water year is predicted to remain at or perhaps slightly above average for the Colorado River as it snakes its way through Colorado and Utah (with allotments also for Wyoming and New Mexico) to Arizona's Lake Powell before concluding in Nevada and California. The annual inflows into Powell function as the gauge of the West's most recent runoff, and this year stands to be solid, but not considerable.
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"It's one of those years where we'll take it," said Kuhn. "It'll bump Powell up 20-to-25 feet in elevation, which is good, but that's still a long ways away from being full. It's still down and there's a bathtub ring."
Powell holds up to 25 million acre-feet. An acre-foot — the U.S. standard measurement for bodies of water — is the equivalent of 326,000 gallons, and, at its projected peak, the northern Arizona reservoir is estimated at no better than 70 percent capacity by this fall, which results in the "bathtub ring," or watermarks along its rock formations.
Another factor for what ends up in Powell, in addition to farther down in lower basin states, is what's drawn off of it for drinking, recreation and crop irrigation en route. Transmountain diversions, which slurp up water off the Colorado River for the state's dense population bases in cities like Denver, Aurora and Colorado Springs, are part of the reality, and a new one could soon be added to the equation.
The U.S. Army Corps of Engineers firmed up its approval of the Windy Gap Firming Project in northern Colorado to pull at least 30,000 more acre-feet from the state's headwater region. The venture would construct the Chimney Hollow Reservoir, with a proposed capacity of 90,000 acre-feet, near the city of Loveland, and further expend the Colorado River before fulfilling out-of-state demands guaranteed under federal law.
"This project would be the first consequential new dam and diversion on the Colorado River in decades, coming at a time when the river is already severely drained and depleted due to overuse, drought and climate change," Gary Wockner, executive director of advocacy group Save The Colorado, said in a statement. "This project would make all of that worse."
Wockner's nonprofit organization promised to scrutinize the decision in anticipation of challenging it in federal district court. They hope to have a judge issue an injunction and prevent the Windy Gap project from ever taking a sip, instead having those seeking the resource to focus on conservation, recycling and growth management to satisfy new consumption requests.
"This draining would occur in order to slather more water on bluegrass lawns on the sprawling cities in the Front Range," Wockner added in the statement. "Every American river deserves its day in court — the Colorado River, which is the lifeblood of the American Southwest, certainly deserves the best legal defense we can give it."
The Windy Gap project is at least a few years off in the distance, if it comes to fruition at all. In the meantime, nearly every storm adds to the volumes of the Colorado River and each drop helps, though is almost never enough.