Prioritizing Prescribed Fire to Protect Water Quality in the Sierra Nevada

Changes in forest structure and climate have made the forests of the Sierra Nevada increasingly vulnerable to high severity wildfire. High severity fires alter soil properties and remove vegetation cover, resulting in elevated rates of erosion and sediment delivery to rivers and streams. Post-fire erosion can severely damage aquatic habitat, degrade water quality, and reduce reservoir storage capacity, making it a threat to river ecosystems and clean water supply. Fuel treatments including prescribed fire are an effective way to reduce fire severity, but existing fuel treatment prioritizations generally do not consider wildfire impacts to water resources. To facilitate the strategic placement of prescribed fires where they will have the greatest benefit to water resources, we developed a regional, hydrocentric fuel treatment prioritization methodology. Our methodology identifies subwatersheds where high post-fire sediment production coincides with high value aquatic habitat and water infrastructure, as well as areas where under-resourced communities and local water quality concerns are concentrated. It also incorporates treatment feasibility and burn probability. We demonstrate this methodology by prioritizing prescribed fire locations within the Cosumnes, American, Bear, and Yuba (CABY) watersheds, a region that is fire prone, ecologically rich, and a significant contributor to California’s water supply. Our model is highly transferable to other regions, making it possible to prioritize fuel treatments for water resources throughout the Sierra Nevada.  

Acknowledgements

Max Moritz, Adjunct Professor, UC Santa Barbara

Luke Hunt, Field Operations Manager, Sierra Nevada Conservancy

Generously supported by the Dipaola Foundation