BOULDER, Colo. — We thought it was like any rainy night, like the last few nights, and enjoyed the smell of rain filling the dry mountains—until my girlfriend Anna’s hair became curly again. Then on our phones, an influx of “Severe alert” texts about flash floods late at night. What was familiar suddenly gave way to an uncomfortable humidity, like New England had shuffled over and settled on the Front Range. No sky but the clouds.
Today, the streets of Boulder echo with fire engines and police sirens through the accelerated beat of rain. Thirty deputies are on patrol, responding to calls for rescue. Louder city sirens, eerie like howling wolves, erupted in the neighborhoods near Boulder Creek around 11:30 a.m. My neighbors stepped out, commented that those were the sirens of air-raids. A crackly woman’s voice came over the siren’s loudspeaker, her message made indistinct by her own echo: “Evacuate immediately,” we heard, though out of context of the rest of her message, who knew what this really meant. “Do not cross Boulder Creek,” which seemed self-evident. We didn’t know if we were being evacuated.
At a media briefing in Eisenhower Elementary School at 12 p.m., Sarah Huntley, spokesperson for the City of Boulder, said there were no evacuation calls for Boulder — yet. She said “The risk is still very real.” She stood in front of a blackboard that read “Sit neat in your seat / Flat bottom, flat feet!”
She urged people who might think any let-up in the rain indicated safety to avoid driving. You can’t tell if the ground’s secure beneath the water. Do not go near the Creek.
Heidi Prentup, commander at Boulder County Sheriff’s Office, confirmed that residents in Jamestown, a small mountain town to the northwest, had been evacuated to the elementary school. She indicated communication with the city was down.
Prentup also confirmed that two people had died in the floods in Boulder County. One drowned, the other died from a structural collapse. No names have been released.
At the media briefing we learned that getting anywhere is tough, if we didn’t know that, because there were 25 to 30 partial or complete road closures. Sections of roads in the mountain canyons had been damaged by mudslides. The traffic light at the intersection of Arapahoe and Foothills Parkway was out, so cars from 16 lanes had to intercept each other as if they were at a four-way stop. Footage from earlier in the day shows rescue crews pulling a man from an upturned car in Rock Creek, in Lafayette. Avoid driving.
Why so much flooding? And flooding from Colorado Springs to Fort Collins — 100-plus miles of Front Range territory?
These cities have been haunted by wildfires. The Black Forest Fire, the Waldo Canyon Fire, the High Park Fire, the Flagstaff Fire.
The process of erosion and runoff in post-wildfire areas is complex, but research suggests fire changes the soil and contributes to erosion and runoff. Wildfires not only burn the litter and dust layer of forest ground, but also change the chemical composition of the soil beneath. The wildfire’s heat volatilizes the soil (if certain organic compounds are present), which makes the soil hydrophobic, or repellent to water, which means post-wildfire soil poorly absorbs rainfall. When short, intense bursts of rain fall over a post-wildfire area, the soil may be prone to heavy, destructive debris flow.
In Lyons, residents have been told not to drink their water, which has been contaminated. Water was flowing over five dams. They need to boil it or drink bottled water.
We went down to Boulder Creek. Some students without shoes watched the muddy and engorged river rushing over trees that had been pushed down into the center of the rushing water. Kids from a family in ponchos shrieked running on bridges over the creek. Usually it flows at 200 cubic feet per second, but according to Huntley, the rains have upped its speed to 1,800 cubic feet per second. In a release, Jim Kircher a U.S. Geological Survey Colorado director, said that at north 75th Street, the creek is flowing at 4,500 cubic feet per second, “a new record for this 26-year-old gauge and more than double the previous record peak flow of 2,050 cubic feet per second, set in 2003.”
The debris line of last night had pushed wood stuff past the trail along the river to higher ground. This was a spectacle. Everyone was talking about snow. Snow was the kaleidoscope through which they see rain. They understand snow.
A few people had umbrellas. Shannon Long at the Army Surplus store said over the phone it was a slower day, but “the people who do come in are buying rain boots and rubber boots and socks, ponchos, rainwear, anything to stay dry.”
People approached the edge of the water like they didn’t expect it to expand. Some waded across still spots. University of Colorado maintenance workers took pictures of the creek on their phones.
Standing in the muddy grass at one juncture where the bike path was claimed by the flooding, Bijan Paul, who works in the Chemistry Department at CU, slowly panned the area with a camera.
“I’m quite habituated to the rain,” he says. “I’m not a U.S. citizen, I’m from India, and where I am from in India, it rains quite heavily.”
Bijan is from Calcutta.
“Last night what I saw was the maximum rain in Boulder, but in Calcutta it is three to four times heavier.”
Does the rain remind him of home?
“We used to make boats of paper, outside my house and in the playground, everywhere. We would set them out on the floods. These memories have been coming back to me.”
[ Top image: Undaunted Boulder citizens ford flood waters on the bike path by the 17th Street bridge, around 10:30 am. Shelby Kinney-Lang. ]