Wildfire and water security: Quantifying the effects of fires on water quantity, water quality, aquatic ecosystems, and community drinking water treatment

Population growth, growing water demand, and increasingly hot and dry climate have increased the vulnerability of US domestic water supply to wildfire. Wildfire regimes have shifted in recent decades, resulting in extended fire season lengths with larger, more severe wildfires. When watersheds burn, they can substantially alter the vegetation and soils that regulate runoff, streamflow, and physical and chemical water quality. Moreover, wildfires can increase the potential for floods, erosion, mass land movements, and introduction of contaminants to streams and rivers. Additionally, wildfires can create functional shifts in the character and reactivity of key water quality constituents, such as dissolved organic carbon (DOC) or dissolved organic matter (DOM). However, research has illustrated highly variable initial responses and recovery trajectories, which are partially due to complex interactions between hydro-biogeochemical processes and other physical, ecological, biogeochemical, or climatic factors. This issue is critical, because wildfire prone forested regions supply water to approximately 60–70 percent of the US population. Moreover, these hazards and contaminants can catastrophically impact downstream community infrastructure, drinking water treatment, public health, and aquatic ecosystem health. The effects from wildfires on water supplies can persist for decades, resulting in hidden costs to communities. In this talk, I will share our past and recent research on the broad issues related to wildfire threats to water security.