Debris flows are probable in the High Park fire area west of Fort Collins, according to a new U.S. Geological Survey report.
An Open-File Report, prepared in cooperation with the Colorado Department of Transportation, details the probability and volumes of potential debris flows associated with the High Park wildfire. The report, presenting a preliminary emergency assessment of the debris-flow hazards, is online.
The results of the study show a potential for substantial debris-flow impacts on structures, roads, bridges and culverts located within and immediately downstream from the burned area. Colorado State Highway 14, in Poudre Canyon, is also susceptible to impacts from debris flows.
"The High Park fire was one of the costliest and most destructive in Colorado history, and unfortunately, without vegetation to stabilize the hillsides, the potential for debris flows to add to the cost of this natural disaster is very real," said USGS Director Marcia McNutt. "For that reason, the USGS worked quickly to produce a report within a month of the fire that assesses where the risk is greatest for debris flows, how large they might become, and what structures could be in their path. This information will help emergency planners prevent the costs from this tragedy from escalating further."
The USGS report presents results of models developed to estimate the probability of potential debris-flow along with associated volumes of debris flows. The models were developed using data collected throughout the intermountain west, and are driven by topographic parameters, soil conditions, the severity of the burn and expected precipitation.
For information on debris flow preparedness, visit the Landslides Hazards Program's During a Storm/Landsite web page.
Did You See It? (DYSI?) is a new website developed by the USGS Landslide Hazards Program that asks anyone who saw a landslide or debris flow anywhere in the country to report their observations. These observations will build a much larger and more complete database that will help scientists gain a clearer picture of how landslides affect the entire United States.
The High Park fire started with a lightning strike June 9 and burned over 87,250 acres, becoming the second-largest fire in recorded Colorado history by area burned after the 2002 Hayman fire. It destroyed at least 259 homes and is second only in destruction of property to the Waldo Canyon fire which started one week later.