"After The Flood: How Climate Change Changed One Colorado Community Forever"
CREDIT: Kiley Kroh
BOULDER, COLORADO — The emotional toll of fighting the 2010 Fourmile Fire — at the time, the most destructive wildfire in Colorado history — remains with Four Mile Fire Chief Bret Gibson like the burn scar left on the mountainside.
He recalls going door to door, giving evacuation orders to his friends and neighbors, all while assuming his own home was burning to the ground. “You’re creating waves of people that are just leaving. It made me physically ill on more than a few occasions, to keep ordering people into homelessness. Even though I know I’m not the fire, part of me has ownership.” Gibson felt that complicity on a deeply personal level then, and continued to for about a year afterward.
As people slowly began to rebuild their lives, there were constant reminders of the fire. “Three to six months down the road, outside aid evaporates. You’re not in the news cycle anymore,” said Gibson. “When the wind blows, your head is messed up. When you smell somebody’s wood smoke, there’s flashbacks.”
In the following months and years, Gibson was well aware of the flood risk that stemmed from the fire. His department devoted significant time and resources to preparing residents, and made it through about 15 flooding events that felt like “adding insult to injury.” Residents were asking him how much longer they’d have to keep adding sandbags around their property and remain on guard for floods. But few if any were fully prepared for what came next.
An historic event
CREDIT: Kiley Kroh
It began raining in the Boulder area on September 9, 2013. But, unlike most rainstorms this year, it didn’t stop. Mike Chard, Director of Boulder County’s Office of Emergency Management remembers the exact moment he realized they were facing a catastrophic event. His office had prepared for serious flood risk in the region and was closely monitoring the weather, but sometime around 5:00p.m. on September 11, he knew something was different: “We had never seen that many storm gauges popping into alarm that quickly.”
Around the same time, Gibson had his own moment of realization. “We knew that we were in for a major, major event when we were getting reports out of El Dorado Canyon, Fourmile Canyon, Twomile Creek, St. Vrain … [It] literally covered 100 linear miles along the Front Range.”
And then, says Chard, “All heck just broke loose and everything was flooding.”
In one week, Boulder received 17.15 inches of rain — an unprecedented amount, given the average for an entire year in the area is just under 21 inches. The 9.08 inches of rain Boulder received on September 12 set an all-time single-day record, smashing the previous high mark by nearly 800 percent. The floods impacted 17 counties, covering an area of 4,500 square miles — roughly the size of Connecticut.
Both Chard and Gibson said they’d never seen anything like it in their lifetimes. Gibson and his crew were forced to evacuate their flood command post and move to higher ground on Gold Hill. He didn’t leave the makeshift post for four straight days, coordinating rescue efforts and listening to harrowing stories of families ripped apart by flood waters and the mudslides they triggered, digging each other out of the mud “with spoons, spatulas, board planks, whatever was around.”
The flood’s toll was tremendous. Eight lives were lost. Entire communities, like Salina and Jamestown in the mountains above Boulder, were wiped out in a matter of minutes as a tidal wave of water and debris came crashing down the canyon. And while the economic cost is still being calculated, initial tallies are astronomical: $430 million to repair damage to roads and bridges, $760 million to fix public infrastructure. That doesn’t include the preliminary tally of $230 million for Weld County, which was hit hard by the flooding. An analysis by the risk management firm Eqecat estimated the total cost of the disaster will exceed $2 billion.
For the members of Gibson’s community who had been devastated by wildfire and then, just as they were slowly getting back on their feet, knocked down again by a weather event the National Weather Service referred to as “biblical,” it’s almost too much to bear.
There is a common perception, according to Gibson, that “major events, life-changing events, happen once.” And when you’re hit with a second life-changing event just three years later? “There’s a tremendous amount of shellshock.”
What’s driving it?
CREDIT: Kiley Kroh
After a brutal year marked by prolonged drought, record-breaking heat and wildfires, the unprecedented flooding event has left many wondering what’s driving it all. Matt Kelsch, a hydrometeorologist with the National Center for Atmospheric Research (NCAR), headquartered in Boulder, explains that while the state of Colorado is no stranger to large precipitation events and floods, as far back as records go, “we’d never seen anything quite like this magnitude over such a large area.”
The intensity of the rainfall over a huge swath of land has a direct link to climate change. Kelsch said that weather is a product of climate and while there’s always been a natural variability in weather patterns, climate change is now “superimposed on that natural variability.”
The changing climate has altered the character of rain or snowfall — “precipitation events” as they’re called in the weather world — because human activity drives up temperatures and, consequently, the oceans and other bodies of water warm, meaning there’s more water vapor in the atmosphere. The result is twofold and seemingly at odds, explains Kelsch: warmer air holds more moisture, which means we could put moisture in the atmosphere and it doesn’t rain. So there could be a long period of time in between rainstorms because the atmosphere can hold the moisture without condensing and dropping it. But when something comes along that causes the moisture to condense and changes it into rain or snow, there’s more moisture available.
Thus, climate change exacerbates both drought and precipitation. “We may be getting longer dry spells but then when it does rain or snow, it’s more intense,” Kelsch explained. Colorado is a case in point, having been gripped by a long-term drought prior to the floods. And as devastating as the floods were, Climate Central points out that one silver lining to the catastrophe was that it increased the percentage of the state that is free from drought — to 15.79 percent from just 1.97 percent before the rains began.
Prior to the storm, Boulder was 3.1 inches behind its normal moisture total. Now, with three months to go, 2013 is already the wettest year on record in Boulder, surpassing the 29.93 inches received in 1995.
The recently-released fifth assessment of the UN’s Intergovernmental Panel on Climate Change confirms this trend toward more extreme precipitation events. Specifically, the report found “extreme precipitation events over most of the mid-latitude land masses and over wet tropical regions will very likely become more intense and more frequent by the end of this century, as global mean surface temperature increases.”
There is also research emerging that connects slow-moving weather systems like the one in Colorado to changes in the jet stream due to climate change. A 2012 report from the National Oceanic and Atmospheric Administration (NOAA) found that the rapid melting of the Arctic “affects the jet stream by slowing its west-to-east winds and by promoting larger north-south meanders in the flow.” Thus, “with more solar energy going into the Arctic Ocean because of lost ice, there is reason to expect more extreme weather events, such as heavy snowfall, heat waves, and flooding in North America and Europe.”
Jennifer Francis, a research scientist at the Institute of Marine and Coastal Sciences at Rutgers University recently told NPR that “an unusual bulge in the jet streams was causing all this weather to stall near Boulder.” And while she notes that the impact of climate change on the jet stream in the Colorado event is unknown, she also emphasizes that an influence is possible “because the Arctic is warming up much faster than other areas, which ‘must have an effect on the jet stream.'”
Other human influences
Matt Kelsch, NCAR scientist, points out that floods differ from hurricanes and other extreme weather in that they’re hydrometeorological events — meaning there’s both a meteorological aspect, the rainfall, and a concurrent, separate hydrological aspect, what happens to the water once it’s on the ground. As human activity alters climactic conditions, it also increases vulnerability to the damage caused by floods. In the area around Boulder, the naturally steep topography helped channel the water into small canyons. This was compounded by urbanization; adding more impervious surfaces like parking lots and shopping malls “contributes to more of the rain running off rather than go into the ground.”
Another factor, the one fire chief Bret Gibson and his community in Fourmile Canyon are feeling so strongly, is the influence of wildfires. Like long-term drought, wildfires effectively seal off the soil, impeding its ability to absorb moisture. Added to that, deforestation from wildfires removes some of the vegetation, and the destabilized ground on the slopes increases the likelihood of mudslides, too.
Climate change enhances the conditions that are fueling these larger and more explosive and destructive wildfires — drought, heat and infestations such as the pine bark beetle. But other human activities are also playing a role.
According to Gibson, wildfires are no longer mitigated by cutting down trees, or “culling the herd.” Drought is making unhealthy forests more unhealthy, and an increasing number of people want to live in vulnerable areas without taking the necessary precautions to limit their wildfire risk. The result, he said, is like driving a car into a brick wall, backing up and running it into a brick wall again, the whole time expecting the car to be fine.
Where do we go from here?
“The climate change is detectable. We definitely see it,” said Kelsch matter-of-factly. “And since climate is made up of weather events then change in the climate is almost certainly going to have some changes in the frequency or distribution of extreme weather events. I’m coming from the scientific perspective; we should be prepared for an increased frequency of this.”
As the director of emergency management for all of Boulder County, Mike Chard has no interest in the scientific and political debate surrounding climate change; his role as an emergency responder centers on one key phrase: preparedness. “I just need to listen to people saying we’re going to see more thunderstorms, we’re going to see more wildfires, more drought. As an emergency manager that’s what I need to prepare for,” he said from the command center where he’d already spent the better part of two weeks. “I don’t care about the politics of it … If that’s what people are worried about, I need to be prepared for it.”
As for the residents of Fourmile Canyon, they’re left with a lot of questions. Namely, how to begin picking up the pieces — in several cases, for the second time in three years. This time, says Gibson, the loss is ten times worse. If a home was lost in the fire, families could deal with the pile of ash that was left behind and begin rebuilding process. After the flood, “not only is the house gone, the bridge is gone, the road that got you to your house is gone, you don’t even know where your house went because the yard is gone,” he said, giving a wearied look to the drizzling rain that was falling outside. “Where do you start?”