Water, we need water
SUMMIT COUNTY – In July 2002, Dillon Reservoir became the emblem in Colorado for a touchy, grouchy summer. The usual blue segued to brown, water turned to mud and then to dry sands, where normally, the water laps at the forest’s edge. A dust devil spun through an area once marked by sailboats.An uncommonly thin snowpack the previous winter had been chased by a windy spring that came weeks early. Forest fires and heat waves soon followed.Climate scientists caution against making too much out of any one year when talking about global warming. Still, in looking ahead at a planet redefined by warmth, the future they describe in Colorado and the Southwest looks much like 2002.
This drought has afflicted the region since 1999. And it has made clear that the Colorado River is a badly strained resource. Water managers are getting a better idea of how much drier this region was for much of the past 1,000 years. The past century was actually unusually wet. Whether this current drought is a result of a normal climatic fluctuation or an early signal of global warming really doesn’t matter. Either way, a fundamentally new way of looking at the river is taking hold. “The Colorado River is the canary in the coal mine for global warming,” says Eric Kuhn, general manager of the Glenwood Springs-based Colorado River Water Conservation District. “You have a system where the demand and supply are so close that a small change of 10 percent in the annual flow at Lee’s Ferry (in Arizona, the divide between upper and lower basin states) could cause a major disruption.” Already, water managers are trying to imagine what this disruption would look like. Allocation of the water among the states is governed by the Colorado River Water Compact of 1922. That compact was signed after a period of what was, in retrospect, extraordinary wetness. The river has carried the same volume only occasionally since then. Water: a hot commodityGiven how little water the river now carries each year, arguably the compact governing the river will call upon Colorado and other upper-basin states to allow more water to flow down to California, Nevada and Arizona. This possibility has the full attention of Glenn Porzak, a Boulder-based water attorney who represents most major water groups and companies in Summit County and the Eagle Valley. “Regardless of whether it’s your normal climatic cycle or the result of global warming, the effect is the same,” says Porzak. “One need only look at what is happening at Lake Powell to see that if things continue, we are going to enter an era of Colorado River Compact calls, which heretofore had not occurred, and that will dramatically change the landscape. I really think people need to pay attention.”
The link between the drought and global warming is still unclear, says Brad Udall, managing director of the University of Colorado-National Oceanic and Atmospheric Administration Western Water Assessment. Still, water managers are increasingly thinking about the specter of global warming. “I think it’s in the back of everybody’s mind,” said Porzak. Danger in degrees Any way you cut it, global warming will redefine the landscape of Colorado and the Southwest. It makes winters shorter and summers longer. During those longer summers, even if precipitation remains the same, warmer temperatures leave forests drier and more susceptible to wildfires. With shorter winters, spring comes earlier, with runoffs cresting in the rivers not in June, as has been the case, but in May or even April. Records in Aspen show the frost-free season has expanded about two weeks into spring, compared with a half-century ago. Dillon Reservoir during the last decade has lost its winter ice more rapidly. And the Colorado River below Glenwood Springs is peaking with runoff a few days earlier. On the West Coast, changes have been even more profound in response to the increase of 1.44 degrees Fahrenheit during the last half-century. The peak of the annual runoff in the Sierra Nevada now comes as much as three weeks earlier than it did in 1948. “The mountain ranges are essentially draining and drying earlier,” said Dan Cayan, a climate researcher with the Scripps Institution of Oceanography in La Jolla, Calif.
Recent studies project that the heat will cause smaller snowpacks across the West. Cayan and U.S. Geological Survey researcher Noah Knowles concluded that a temperature increase of about 4 degrees Fahrenheit would reduce the Sierra Nevada snowpack by a third by 2060, primarily at lower elevations, and halve it by 2090. The reduced snowpack forecast for the Rocky Mountains is less severe than on the West Coast, but one study foresees 30 percent less snow. Runoff here can be expected to be four weeks earlier within 50 to 90 years, says Kevin Trenberth, who heads the climate change analysis unit at the National Center for Atmospheric Research (NCAR) in Boulder. All of this has water managers thinking more dams for Colorado. “My attitude at this juncture is there is no such thing as too much storage,” says Porzak, whose clients include Vail Resorts. Disappearing glaciersNo large rainstorm had occurred, yet a gauge on Dinwoody Creek outside of the small town of Dubois, Wyo. suddenly shot up to 900 cubic feet per second in September, 2003.Grasshopper Glacier, like so many glaciers across the world, has been melting. The ice, a mile wide and two miles long, is located at an elevation of about 12,000 feet along the spine of the Wind River Range.
The glacier had served as a dam to an unnamed lake. As the glacier melted, the lake’s 650 million gallons cut a new channel through the ice, slowly at first and then in a torrent, leaving a wall of ice 60 feet high. Below, as the water raced down the mountain, it ripped a trench through the soil that in places was estimated to be 30 feet deep. “The scale is so enormous. It sort of makes you feel a little small,” said Liz Oswald, a hydrologist with the U.S. Forest Service who flew over the area after the deluge.The torrent in the Wind Rivers came as no real surprise to David Naftz, a Salt Lake City-based geochemist with the U.S. Geological Survey. Three times from 1991 to 2002, Naftz and others have climbed high into the Wind River Range to bore another glacier several miles away.He has concluded that, while temperatures around the globe during the last century rose 1 to 2 degrees Fahrenheit, high in the Wind River Range the temperature rose 4 to 9 degrees in just the last half-century.”There appears to be something that is going on that is accelerating these temperature increases in high elevations,” says Naftz. The cause, he adds, is still up for speculation. University of Zurich researchers in 1998 found that the glaciers of the Alps have lost 30 to 40 percent of their surface area and about 50 percent of their volume since 1850. Another study found that glaciers in New Zealand’s southern Alps have lost 25 percent of their surface area.Glaciers in the Caucus Mountains, Europe’s highest range, have shrunk to half their size. The glacier near the base camp for Tenzing Norgay Sherpa and Edmund Hillary has retreated three miles since their 1953 climb of Mt. Everest. And in equatorial Africa, Hemingway’s “The Snows of Kilimanjaro” may soon become a memory, as 75 percent of the glacier on the mountain has disappeared. The rest is expected to follow soon. At a conference of ice-borers earlier this year in Greenland, scientists were urged to hasten to the mid- and lower-latitude glaciers to retrieve ice cores before the ice and the stories they tell have vanished.
Support Local Journalism
Support Local Journalism
As a Summit Daily News reader, you make our work possible.
Now more than ever, your financial support is critical to help us keep our communities informed about the evolving coronavirus pandemic and the impact it is having on our residents and businesses. Every contribution, no matter the size, will make a difference.
Your donation will be used exclusively to support quality, local journalism.
Start a dialogue, stay on topic and be civil.
If you don't follow the rules, your comment may be deleted.
User Legend: Moderator Trusted User