Science Inventory

Post-Wildfire Water Quality and Aquatic Ecosystem Response in the US Pacific Northwest: Science and Monitoring Gaps

Citation:

Wall, S., J. Compton, A. Coble, B. Haley, J. Lin, A. Myers-Pigg, J. Reale, K. Wampler, A. Swartz, K. Moffat, K. Bladon, K. Carpenter, H. Chang, J. Chen, D. Donahue, C. Eckley, A. Hohner, P. Kiffney, L. Miralha, P. Regier, J. Seeds, AND M. River. Post-Wildfire Water Quality and Aquatic Ecosystem Response in the US Pacific Northwest: Science and Monitoring Gaps. Environmental Research: Water. IOP Publishing, BRISTOL, Uk, 2(1):015004, (2026). https://doi.org/10.1088/3033-4942/ae36cb

Impact/Purpose:

In the summer and fall of 2020, California, Oregon, and Washington experienced unprecedented and catastrophic wildfires that have resulted in staggering losses of life and property. Within the forested landscape, fires killed trees and potentially altered soil properties and hydraulic dynamics in ways that may change soil physical, chemical and biological functioning. Jana Compton along with ORISE fellow Sara Wall based the US Forest Service assembled a team to review the science and monitoring gaps around the post-fire aquatic response. This manuscript addresses the gaps in monitoring, data analysis and assessment post-fire and serves as a call to arms for more research and analysis of existing data.

Description:

An increase in the occurrence of large, high severity wildfires in the western Pacific Northwest (PNW), USA, has created an urgent need for science to better inform forest management and policy decisions to maintain source water quality in the region. The western PNW faces similar challenges to other regions with shifting wildfire regimes and large population centers reliant on surface water from forested catchments. However, the uniquely wet and highly seasonal climate of the western PNW suggests that findings from other, more frequently burned regions may not be directly applicable. To identify science, monitoring, and management gaps and opportunities in the western PNW, this review was collaboratively undertaken by academics, non-government and industry representatives, and local, state, and federal government entities who have been working together since the 2020 Labor Day fires in Oregon. Focusing on Oregon and Washington, we found that monitoring networks for continuous water quantity and quality cover much of the state with greater representation in western U.S. ecoregions, but few studies have analyzed and published these data to capture and communicate the post-wildfire response. Approximately half of the streamgages in Oregon and Washington record major water quality parameters, and hundreds of sites in the area have discrete sampling for a wide range of water quality constituents. Still, numerous gaps exist in understanding the short- and long-term impacts of wildfire on hydrology, water chemistry, including pH and dissolved oxygen, mobilization of metals, aquatic ecosystems, and downstream drinking water treatment. Collective action to further collect, analyze, interpret, and publish the key data could help improve our understanding of post-wildfire water quality impacts in this and other increasingly wildfire-affected regions.