Assess Biological, Hydrological, and Geomorphological Conditions

Forest Health and SMPs

Forests are interconnected with rivers and watersheds. With a changing climate and prolonged drought, Colorado is seeing an increase in frequency, intensity, and impact of wildfires across the state. Rivers and riparian areas are important in minimizing the impacts of fire by serving as fire breaks, providing buffer zones to filter runoff, and offering important wildlife corridors. However, post-fire conditions can negatively impact stream conditions. For example, flash floods producing hillslope erosion and mud and debris flows can cause water quality impairments, exacerbate fluvial hazards, and stress or completely devastate aquatic communities. Understanding the potential impacts of fire before they inevitably occur is integral to making stream management decisions in fire-prone watersheds. Information is needed to demonstrate where there are values that may need protection, high risk areas, and potential mitigation strategies. Additionally, stakeholders across the state have questions as to how changing forests and climate change will impact the hydrologic cycle in their basin. Research is ongoing as to the impacts of forests and fire on snowpack, evapotranspiration, sublimation, and runoff conditions.

As a result, incorporating aspects of forest health and post-fire modeling and assessment can be beneficial to an SMP/IWMP planning effort. However, this can be a challenging and sometimes overwhelming endeavor. As many SMP/IWMP coalitions are considering how best to incorporate forest assessments in their processes, forest health and watershed health planning continues to evolve and present new opportunities for effectively integrating these components into SMP/IWMP processes.

Leah Weaver collecting a benthic macroinvertebrate sample on the Conejos River (Daniel Boyes/Rio Grande Headwaters Restoration Project)

The Colorado Water Conservation Board has taken steps to help support SMP/IWMP coalitions and Basin Roundtables as they grapple with these plan scoping questions. Resources include:

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The CWCB’s Wildfire Ready Watersheds initiative has significant overlap with stream management planning and watershed planning. The effort involves a statewide susceptibility analysis that produces a map showing the most susceptible HUC12s in the state to wildfire impacts and develops a mitigation framework for communities that they can implement themselves, with CWCB reaching out to priority areas and promoting implementation of the framework. Contact Chris Sturm for the most current information about the Wildfire Ready Watersheds Program.

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The Forest Health Study: 10 Takeaways to Inform the Colorado Water Plan was completed by the Colorado Water Conservation Board to evaluate relevant forest health research, identify active workgroups focused on watershed and forest health, and assess modeling and analysis tools for critical decision making.

These examples outline various approaches that SMP/IWMPs have taken to incorporate forest and fire information into their assessment and planning process. The examples vary in scale based on the SMP/IWMP’s resources, stakeholder interests, budget, and other factors.

Upper San Juan River Watershed Enhancement Partnership

Integration of forest collaborative groups and stream management planning took place in the Upper San Juan River following the 2013 West Fork fire, lending a watershed focus to forest management. The assessment sought to identify and map high-risk drainages for potential impacts from wildfire activity and sediment delivery hazards to water infrastructure and high-value aquatic or riparian areas. The Partnership partnered with technical consultants to map the planning area for the IWMP, targeting forested, high mountain areas to gather data on air temperature, precipitation, soil moisture, and snow melt timing. Forest response maps were also created to visualize canopy wetness, wildfire potential, and sediment delivery. Finally, five large channel response zones were identified across the targeted watersheds. Ultimately, these data informed the areas of concern, needs, and prioritized actions for the IWMP pertaining to wildfire, forest health, and drinking water. For forest health, needs include (1) improving the understanding of the relationships between climate change, forest succession, forest management, and water stress in forests in mid- and high-elevations; and (2) increasing the geographies and stream miles covered by risk reduction and wildfire response plans that contemplate future impacts of post-fire flooding and debris flows on infrastructure and environmental stream attributes. For drinking water, the need exists to minimize negative impacts and seek multiple benefits for environmental and recreational water uses during planning for future municipal water supply projects and reducing risks to municipal water supply associated with wildfire.

For more information, please view an April 2022 peer-learning call presentation on this topic.

St. Vrain and Left Hand SMP

The St. Vrain and Left Hand SMP utilized a USFS Wildfire Hazard Potential modeling approach derived from LANDFIRE (Landscape Fire and Resource Management Planning Tools) to map the wildfire risk in the watershed to inform decisions on managing for the conservation targets identified in the SMP. LANDFIRE is a shared program between the wildland fire management programs of the US Forest Service and Department of Interior, providing landscape scale geo-spatial products to support cross-boundary planning, management, and operations. The specific dataset utilized by St. Vrain Left Hand was developed by USFS Gregory Dillon and Julia Gilbertston-Day with background data, documentation and metadata to describe the approach. Conservation targets identified in the SMP include key plant, macroinvertebrate, wildlife, and fish species in each watershed zone in addition to key stressors such as wildfire potential, climate change, and invasive species. The “very high” and “high” categories in the wildland fire potential data layer were used. Priority opportunity areas were then identified where high fire risks occurred in the vicinity of high value habitat areas along the creek. In addition, improved forest fire management was highlighted as a need, particularly where sources of drinking water are at most risk (e.g., around the reservoir).

Left Hand Watershed Center

The Left Hand Watershed Center has been implementing their Adaptive Management at Scale project for several years. Important variables of this process include identifying desired conditions, monitoring representative sites, hosting annual workshops, implementing collaborative, multi-benefit, and cross-boundary projects, and annual State of the Watershed Reports. This project focuses on the St. Vrain Basin, including Left Hand Creek and Boulder Creek. Forest health is incorporated in various ways. Forest conditions across the basin, species in the forests, and tree density are among the factors under consideration for the overall watershed assessment. Desired conditions aim for a forest structure that supports high-quality habitat for native wildlife and improves resiliency to high severity wildfires, floods, and other disturbances now and in the future.

Additional Resources

Organizations and projects outside of the SMP/IWMP realm are increasingly tracking and connecting people to resources and research about managing for forest health and tying it to their watershed goals. Organizations such as the Coalition for the Poudre River Watershed, Mountain Studies Institute, and Colorado Forest Restoration Institute offer a variety of case studies and educational examples that could be pertinent to SMP/IWMP processes.
Sara Goeking, University of Utah Center for Colorado River Studies, 1-hr Webinar: Linkages between forests, snowpack, and streamflow in western coniferous forests
Climate-driven disturbances in the San Juan River sub-basin of the Colorado River research article.
Forest Action Plan (Colorado Statewide Forest Resource Assessment & Strategy) is the first geospatial assessment completed by the Colorado State Forest Service.
Charlie Luce, US Forest Service, Rocky Mountain Research Station produced an interactive map viewer of water yield from National Forest lands and series of maps predicting water yield under climate futures.
Caitlin Coleman, Water Education Colorado article titled “Six Feet in Solidarity – Week 6: Forest and Watershed Health” discusses topics such as the importance of forested watersheds protecting clean water and the value of partnerships in water resources. It also cites additional resources.
Niah B.H. Venable et al., Colorado State Forest Service, wrote a synthesis report on House Bill 16-1255 and the results of a body of research focused on the effects of wildland fire, insect and disease outbreaks, a changing climate, and roads and human disturbances on Colorado’s forests and water supply.
Jeffrey H. Writer and Sheila F. Murphy, US Geological Survey, highlighted the impacts of the Fourmile Canyon Fire and the implications for drinking-water treatment and source-water quality.

SMP Nuts and Bolts

Assess Conditions and Identify Risks