GLENWOOD SPRINGS, Colorado – The flash flood swept down Glenwood Canyon with such force it changed the course of the Colorado River. Torrents of mud, boulders the size of cars and overturned trees plunged into towering rock walls carved out over millennia.
When it was over, the July 29 mudslide left a gaping hole in Interstate 70. The river of mud had pierced a wall and swept the freeway, sending the bridge eastbound crashing into the waterway. and burying one of Colorado’s most scenic drives under 6 feet of debris.
“This is land the dinosaurs walked on, and it’s all gone,” said Tim Holbrook, a supervisor with the Colorado Department of Transportation, who has seen all kinds of blizzards, floods and fires from forest in 19 years in road maintenance, but nothing like the spectacle of this summer. .
When the highway through Glenwood Canyon was built in 1963, it was considered an engineering marvel, an ambitious construction project that preserved the beautiful surroundings. But the 12-mile corridor through the canyon in western Colorado leaves little room for maneuver, and traffic is easily disrupted.
Experts say the situation is magnified by climate change and its cascade of crises this summer: drought, forest fires, monsoons and mudslides.
The physical alterations have resulted in road closures, detours lasting several hours, environmental disasters and economic displacement. And they have sparked tough questions about aging infrastructure designed decades before climate change took center stage in public discourse.
“That should be a warning, the canary in the coal mine,” said Paul Chinowsky, director of the Department of Environmental Design at the University of Colorado. “It’s time to go back and see where our critical transport routes are, as most of them are probably quite vulnerable to this type of situation.”
“We cannot let the pride or arrogance of engineering trump the science of saying that what you design no longer exists,” he said.
Maintenance crews continue to repair a 1 ½ mile section of the highway. Traffic is reduced to one lane in each direction where it was most damaged. Workers were harassed by smaller slips and weather threats that forced them to close the highway nine times. The slide also removed utilities and communications networks.
“We have this great confidence that this one thing will never fail. And then, when it fails, everyone is wondering, ‘How did that happen?’,” Chinowsky said. “All it takes is disruption, and you really have economic damage.”
The closures have deeply affected Glenwood Springs, a tourism dependent resort town whose renowned hot springs have drawn visitors for generations. Many people who booked hotels this summer and coming from the Denver area were subjected to three to four hour detours. The historic Hotel Colorado suffered $ 72,000 in one-day cancellations. Hospitality workers couldn’t get to work, and some Valley View Hospital staff had to be helicoptered from their homes across the slide.
“Our resilience is being tested,” said Mayor Jonathan Godes. “We’re going to recover, but the communities that can’t, the communities that don’t have the capacity, the funding, the tax base to be able to do projects, to provide a bit of resilience, of redundancy, are really going to have evil in the new paradigm. “
When the freeway is closed, traffic is diverted to Steamboat Springs, a town of 13,000 people about a three-hour drive from Glenwood Springs, which is a gateway to some of Colorado’s best skiing and outdoor activities. Hundreds of semi-trailers and semi-trailers roll through the downtown corridor lined with shops and restaurants, braking at eight traffic lights and spewing exhaust fumes.
“This is not how we want people to experience our beautiful place,” said Kara Stoller, CEO of the Steamboat Springs Chamber of Commerce. “When I-70 is closed in Glenwood Canyon, residents aren’t even motivated or excited to drive through town.”
Andrew Hoell, a research meteorologist with the National Oceanic and Atmospheric Administration, said “really extreme” weather events about a year apart led to the mudslide.
Record-breaking precipitation from January 2020 to May 2021, combined with historically high temperatures, created “a perfect storm,” he said. A NOAA report said the phenomenon was “exceptional in the climatic record of observation since 1895”.
“We call these compound and cascading events, where they build on top of each other and produce very bad consequences in the end,” Hoell said.
The evidence that the mudslide was caused by climate change is “overwhelming,” he said. “The higher temperatures create an increased demand for moisture on the land surface, which makes droughts worse.”
The drought quickly led to forest fires. Last year, the Grizzly Creek fire destroyed trees and other vegetation on both sides of the highway. It burned for months, destroying over 32,000 acres and closing the freeway in Glenwood Canyon for two weeks. The fire was so intense that ashes fell in Denver, 155 miles away.
Then came this year’s seasonal monsoons, which typically bring on intense mountain storms that pass quickly. This dumped more than 4 inches of rain in five days, double the average monthly rainfall, causing the ground to collapse over the burn scar and trapping more than 100 people in vehicles below. The mudslide blew up the parapet of I-70 westbound, ripped off the road on the eastbound freeway, and crashed into the Colorado River.
Drone video revealed a gash in a mountain rising thousands of feet into what was once a forest. The collapse left 6 feet of mud and debris on the road, which took 2.5 weeks and 4,000 trucks to clear.
“The problem most people have when they look at the climate is that they put it in silos, that they compartmentalize it,” Chinowsky said. “And that’s not how things work when it comes to a system. Everywhere you push it, another place is going to get out of balance, and that’s exactly what happened with Glenwood Canyon. . “
Previously, the Colorado River flowed widely through the passage, but it narrowed with the accumulation of sediment, affecting the habitat and food supply of trout and other fish. Biologists fear that the fish that have survived will not be able to build their nests, called nests, to lay eggs, and that the insects they feed on will perish.
“We have had reports from people who have been rafting and anglers who have noticed dead fish as a result of the mudslides,” said Lori Martin, aquatic biologist at Colorado Parks and Wildlife. “But we don’t know what that means in the long term in terms of impacts on the entire population and fish communities.”
Today, massive sandbags weighing 3,000 pounds are the first line of defense against another slide. The state is working to fully reopen the most damaged portion of I-70 via Glenwood Canyon by Thanksgiving.
“Who knows what the future holds? Said Holbrook of the Transportation Department, who is bracing for the next slip and other damage to the scenic route.
“You can pretty much get by with anything,” he said. “What is viable? Can it be built? Yes, but at what price ?