Impact Forecasting launches new model for Colorado floods

Impact Forecasting, the catastrophe model development arm of Aon Benfield, has developed a new scenario model to quantify losses from flooding in Colorado, after that state saw record rainfall last month.

Heavy rainfall led to major flash flooding across the northeastern part of the state, causing nine deaths and damaging or destroying at least 17,983 homes and 968 commercial properties, according to Aon, citing the Colorado Office of Emergency Management.

The new model is based on a USGS (United States Geological Survey) Digital Elevation Model (DEM), the model analyzes insurance portfolios either across the state of Colorado at a 100-metre resolution; or by focusing on the five cities that experienced most damage – Boulder, Longmont, Fort Collins, Greeley and Colorado Springs – at a more detailed 30-metre resolution.

It also uses the record levels of rainfalls, recorded by USGS’s network of stream gauges along several rivers throughout Colorado’s Front Range, according to Aon.

“The scope of damage and the overall scale of impacts make this the costliest flood in Colorado’s history, and the first such event to cause more than $1.0 billion dollars in uninflated economic damages in the state,” Siamak Daneshvaran, head of research and development at Impact Forecasting noted in a statement.

“The new scenario model is part of Impact Forecasting’s U.S. river flood probabilistic model and will help insurers gauge the financial impact and probability of this event’s potential recurrence.”

Image: Colorado Springs flood looking Northwest into Waldo Canyon fire burn scar. The burn scar allowed most rain water to rush unimpeded into the rivers and creeks of the area, exacerbating the flooding. (Source: Impact Forecasting)