Learning the lessons of Yellowstone flooding: University researchers scramble and capture data

On the night of June 12, 2022, a storm system began dumping rain on the Beartooth Range of northern Wyoming and southern Montana. Over the next 24 hours, about four inches fell on the still snow-covered peaks of the northern Rockies. The rain-on-snow effect drove a rapid loss of mountain snowpack. Because of this, streams and rivers quickly swelled out of their banks, and quiet mountain towns were slammed with flash floodwaters. Bridges, roads and homes in and around Yellowstone National Park were swept away in the torrent, isolating communities and stranding tourists.

Teams of first responders were mobilized in the hours and days after the disaster. Among them was a specialized group of scientists who study civil infrastructure. "Our group of students and researchers were loaded with scientific equipment and on the road in 24-hours after receiving the call to help assess and map flood damage," says Bret Lingwall, Ph.D., who is an associate professor of civil and environmental engineering at South Dakota Mines.

Lingwall is one member of the National Science Foundation's Geotechnical Extreme Events Reconnaissance (GEER) effort. This organization includes teams of scientists across the country who spring to action in the wake of disasters to collect perishable post-disaster data. Their goal is to capture critical data on infrastructure and disaster impacts that can be used to inform better prevention and resiliency in the future.

GEER's response to Yellowstone flooding was led by Anne Lemnitzer at UC Irvine and Kevin Franke at Brigham Young University. They called Lingwall and his students in to help. Lingwall says South Dakota Mines had some important tools needed in the effort.

"Thanks to multiple donors and outside funding, we have a fleet of drones and laser scanners across campus that are equipped for detailed 3D mapping," says Lingwall.

Before drone and laser scanning (i.e. LiDAR) technology, mapping was more tedious. Today, drones are equipped with high end cameras and laser technology that can provide very accurate images and topographic computer models. "We also maintain a pool of trained and FAA licensed drone pilots, mostly students, who are ready to mobilize at any time for disasters like this," says Lingwall.

The team drove to Gardner, Mont., set up a home base and spent a week deploying drones to map both areas that were heavily damaged by flooding and those that survived, despite the high water. "A lot of our work is trying to determine why one piece of infrastructure failed in high-water and why another one did not," says Lingwall.

Knowing what homes, roads and bridges crumbled and knowing which structures remained can be highly valuable in the long-term effort to build more robust infrastructure.

Lingwall says GEER's report can also add to ongoing research on things like slope stability and landslide reduction, bridge and highway resiliency and home and building location. His students are using samples collected during the flooding in their coursework that will add to ongoing research. "The purpose of GEER is to collect this swath of perishable data that will go away as soon as infrastructure is repaired. We use that data to share with multiple agencies, highway departments, community planners, engineers, emergency responders and others who can use the information to build back in a way that will better survive the next disaster," he says.

Lessons Learned

For Lingwall, the lessons of the floods that hit Yellowstone include the need to update our standards. Current building codes require designs that can withstand a 100-year flood event. "The next generation of building codes, coming over the next 10 years, will require infrastructure to withstand a 500- or 1000-year flood event," Lingwall says. "In earthquakes, we use a 2500-year criteria and this has done wonders for surviving these events. Disasters like (the 2022) Yellowstone floods show that designing for a 100-year event was not the right criteria. It does not make sense."

Developing more resilient infrastructure will save taxpayer money in the long-term. "People often only want to talk about up-front costs, and they will increase. What we don't like to talk about is what happens after the disaster hits and everyone needs help from an agency like FEMA to recover. Building with more resiliency in the beginning will save money down the road," Lingwall says.

Lingwall points to towns like Rapid City, SD, which saw a flash flood roar out the Black Hills and kill more than 230 people in 1972. The city rebuilt in the wake of that disaster with an open floodway, including multiple parks along Rapid Creek. But Lingwall points to USGS studies that show much larger floods in the distant past on Rapid Creek than the 1972 disaster. "This is the thing that terrifies me after seeing the flooding in Yellowstone," he says. "The paleo-flood record shows much bigger disasters than we have ever seen in our collective memories as a community, are more than just possible in the future, but likely."

Lingwall notes that there are no easy solutions to these challenges as socioeconomics play a big role in how and where we build in the future. "These are decisions we have to adopt as communities," he says.