Two people died after flash floods swept away a camping trailer in the Buckhorn Canyon area Larimer County in Colorado, USA, on 15 July 2022 after heavy rain in the burn scar left by the 2020 Cameron Peak Fire.
Larimer County Sheriff’s Office Communications Center received multiple reports of flash flooding in the Glen Haven and Crystal Mountain areas west of Fort Collins. Roads were washed out and conditions were dangerous. Residents were advised to shelter in place. An evacuation centre was set up by the Red Cross for those unbale to return to their homes.
Larimer County assessment teams determined that one home was destroyed and 5 others were damaged.
Local media quoting National Weather Service meteorologists said 17 mm of rain fell in 20 minutes.
Meanwhile heavy rain on burn scar areas in Arizona has caused problems in the Flagstaff area of Coconino County. The area is prone to flooding and saw flooding in July and again in August last year. Authorities have there responded quickly to the recent flood threats and Governor Doug Ducey ordered members of the Arizona National Guard to help with flash flood mitigation efforts.
The governor said, “We are working around the clock with the local officials and our Department of Emergency and Military Affairs to ensure we get all the necessary resources out to Coconino County as soon as possible.”
Increased Flood Risk in Burn scar Areas
Due to drastic alterations of soil properties and to the land surfaces caused by wild fires, the risks of flash floods, debris flows and severe erosion increase for burn scar areas.
William R. Cotton, Professor Emeritus of Meteorology, Colorado State University wrote last year that wildfire burn scars can also intensify and even create thunderstorms that lead to catastrophic flooding.
Featured photo: Flood debris in Flagstaff Arizona, July 2021. Photo: Flagstaff City Government