The Rocky Mountains’ winter snow is gradually being replaced by spring rain, and it’s likely to get worse in the decades to come, a government study released Thursday indicates.
The U.S. Geological Survey found Rocky Mountain snowpacks have declined 30 to 60 percent in parts of the Rockies over the past three decades, bucking a centuries-long trend.
This year, northern Colorado snowpack was abundant — two to three times its 30-year average — and a cool May could push the end of the spring runoff into July, forecasters have said.
“This year’s gains are only a small blip on a century-long snowpack decline,” the USGS said in announcing its findings.
The dire long-term forecast cites warmer springs, earlier snowmelts and shifting winter storm patterns, all possible byproducts of global warming caused by greenhouse-gas emissions, according to the USGS.
While that could prove disastrous for Colorado’s ski and rafting industries, it’s too early to say if it means less water overall, said Marc Waage, the manager of water-resources planning for Denver Water, which supplies 1.3 million people in the metro region.
“I don’t think from this study you can conclude that the overall amount of water is going to decline,” he said, “because we could be compensating snowpack with rain.”
Denver, he says, has the luxury of large mountain reservoirs to store water and allocate it year-round. Agricultural irrigators who use their water rights in the spring, however, might not be so lucky.
In most Western states, snowpack provides 60 to 80 percent of year-round water supplies.
U.S. Interior Secretary Ken Salazar, a former U.S. senator from Colorado, provides a guide to deal with climate change.
“It helps land managers adapt to changing conditions on the ground, assists water managers with planning for the future, and gives all of us a better understanding of the real impacts that carbon pollution is having on our resources and our way of life,” Salazar said in a statement.
While snowpack has fallen since the 1980s, forest fires have grown “larger, more frequent and harder to fight,” according to USGS ecologist Gregory Pederson, the lead author of the study, who works at the Northern Rocky Mountain Water Science Center in Bozeman, Mont.
Less mountain snow could be a real downer for Colorado’s economy.
The state’s 26 ski resorts saw an estimated 12.2 million skier visits this season and funnel tens of millions of dollars into the state’s economy each year.
Moreover, a U.S. Forest Service study released at a conference in Breckenridge last month suggests ski demand nationally could grow by up to 50 percent by 2060.
Joey Bunch: 303-954-1174 or email@example.com