Wildfire and Watersheds

PURPOSE

There is growing interest from water providers and watershed groups in proactive forest management to reduce the risk of wildfire impacts to water resources, yet forest and watershed managers have limited tools to assess baseline risk, estimate the benefits of forest management, and prioritize forest management activities over large landscapes. We are leading a research effort to model fuel treatment effects on wildfire and watershed response, with emphasis on risk assessment and fuel treatment planning applications. We hope to put better assessment and planning tools in the hands of forest managers, watershed groups, and policy makers to improve watershed management decisions.

CONTEXT

Wildfire can dramatically increase erosion in forests by reducing tree cover and altering the physical and chemical properties of soils. Post-fire ash, debris, and sediment can complicate water treatment and conveyance, and decrease water storage for downstream communities, as exemplified locally by the Buffalo Creek, Hayman, and High Park Fires. Numerous water utilities, watershed groups, and forest collaboratives have responded by funding fuel reduction work to mitigate future wildfire impacts, and need quantitative estimates of effects to prioritize work, set goals, and monitor progress.

OUR INVOLVEMENT

Our research improves modeling for fuel treatment, wildfire, erosion, and sediment transport systems. We assess risks and use decision support tools to make effective evaluations. We also work with watershed stakeholders, forest collaboratives, and land managers on assessment and planning.

METHODS

We use wildfire behavior, erosion, and sediment transport modeling to estimate conditional fuel treatment effects on erosion and downstream sediment delivery, informed by extensive local research on post-wildfire erosion. Wildfire is highly variable in space and time, so conditional fuel treatment effects are converted to risk reduction using spatial estimates of burn probability. We use optimization approaches to allocate fuel treatment across large landscapes with variable fuel treatment effects, constraints, costs, and connectivity to downstream values to minimize the risk of downstream impacts.

RESULTS

Watershed investment project team members contributed to a recent article in the Journal of Environmental Management examining the potential return on investment for fuel treatment work measured in terms of avoided downstream sediment costs at Strontia Springs Reservoir in Denver Water’s South Platte Collection System.

IMPACTS

The Peaks to People Water Fund is using our analytical framework to inform the design and priorities for a water fund in northern Colorado (more in applications). The Colorado State Forest Service cited our work in a report to the state legislature as an example of needed improvements in assessment and prioritization to support watershed management in the state.

Screenshot of the Watershed Investment Tools created by Peaks to People

APPLICATIONS

We worked with the Peaks to People Water Fund, co-founded by the Center for Collaborative Conservation at Colorado State University and the Nature Conservancy, to develop a combined risk assessment and fuel treatment planning decision support system, called the “Watershed Investment Tool”. The Watershed Investment Tool uses spatial information on fuel treatment effects, constraints, costs, and connectivity to downstream values to develop optimal landscape-scale fuel treatment risk reduction plans.

Colorado Forest Restoration Institute