Fourmile Canyon Wildfire

In September 2010, the Fourmile Canyon wildfire burned approximately 6,200 acres of forest and 168 structures in the foothills west of Boulder, Colorado.  In the post-fire condition, the steep terrain, with average slopes exceeding 30 percent over more than half the burned area, posed a greatly increased risk of flooding and debris flows.  WWE was contacted by Boulder County and the City of Boulder to evaluate the post-fire runoff from several drainages for a range of storm events.

Findings from the HEC-HMS modeling analysis were used for emergency preparedness planning.  WWE was also tasked with evaluating the projected post-fire hydrologic recovery of the watershed and planning measures to reduce the impact from debris flows.  This aspect of WWE’s work involved cost-benefit analysis of multiple approaches in which we evaluated trade-offs between the costs of implementing watershed-based controls versus the costs of cleaning up after debris flow events, both with and without the distributed control strategies.  WWE’s analysis helped Boulder County to project anticipated debris flow clean-up costs and to identify cost-effective watershed-based best management practices.

Subsequently, WWE performed additional modeling for the City of Boulder to assess the changing runoff conditions as the watershed recovery progressed.

WWE has performed similar services to address several recent wildfires in Colorado and the Western United States.