In September 2013, the Colorado Front Range underwent catastrophic flooding during a week-long rain event when 8 to 18 inches of rain fell over the mountain front and neighboring plains. The flood caused considerable damage to property and infrastructure over 1150 square miles, including substantial portions of the Arapaho-Roosevelt National Forest.
Hundreds of landslides initiated on steep hillslopes during this event and delivered copious volumes of sediment to adjacent streams. Channels widened, entrenched, relocated, and aggraded in response to high discharges and new sediment loads.
Research on the type and degree of geomorphic changes to streams on National Forest System lands and patterns of recovery in these landscapes has been initiated. One research question looks at geomorphic and aquatic recovery patterns in channels that are “restored” following the flood (that is, channels were reformed or relocated, large wood removed, addition of rip-rap, etc.) differ from channels that are left largely to natural processes.
National Forests and surrounding lands are dynamic, hazard-prone natural landscapes; community residents and policy makers should understand the risks inherent to people living and recreating in these landscapes.
Recovery on National Forests will look different from, and occur on different timescales than, recovery along highways and in communities. The Forest Service strives to take a balanced and thoughtful approach to restoring the landscape that is rooted in the Multiple-Use mandate; therefore, recovery may include elements of both rebuilding infrastructure and promoting ecological resilience.
It will be important for both communities and the Forest Service to continue dialogue over time, communicating both about the impacts and effects likely to be felt years into the future, as well as the choices that society has for reducing future vulnerability to natural disasters.
For more information, read the Science You Can Use Bulletin Our Relationship with a Dynamic Landscape: Understanding the 2013 Northern Colorado Flood.