RAPID: Impact of Extreme Weather Events on Biogeochemical Cycling and Microbial Dynamics: Assessing Post-Hurricane Helene Shifts in the Oconee River Watershed

This rapid-response research project investigates the impacts of Hurricane Helene on the Oconee River watershed, an essential water source for Athens-Clarke County, Georgia, and surrounding communities. As climate change drives more frequent and intense extreme weather events such as hurricanes, it becomes critical to understand how these storms influence our natural water systems.

Hurricane Helene’s heavy rainfall and flooding likely washed pollutants from urban, agricultural, and industrial areas into the watershed, introducing contaminants like pesticides. These pollutants disrupt the natural nutrient cycles and alter microbial communities that play a vital role in maintaining ecosystem balance. By examining the immediate and longer-term effects of this hurricane, the research will reveal how such events impact water quality and ecosystem health.

The study holds significant value for advancing our scientific knowledge of climate impacts on natural systems and supports efforts to protect public health by informing better water management practices. The outcomes of this study will contribute to a broader understanding of hurricane-induced changes to watershed ecosystems, especially in relation to climate-induced extreme events.

The broader impacts of this research extend to environmental and public health, as extreme weather events increasingly threaten water quality in vulnerable regions. With the North Oconee River watershed supplying drinking water to Athens-Clarke County and neighboring areas, the study’s findings will help to determine whether pollutants mobilized by hurricanes like Helene pose risks to human health and ecosystem stability.

By identifying changes in nutrient balances and microbial community structures, the research will aid in developing strategies to protect water resources and enhance watershed resilience. Beyond scientific contributions, this project will foster greater public awareness of the importance of watersheds in safeguarding environmental health and public safety.

This research builds upon monthly monitoring of pre-hurricane data on nutrient levels (such as nitrate, phosphate, and sulfate), organic contaminants, and microbial diversity in the Oconee River watershed. Utilizing this baseline, the study will measure post-hurricane changes to assess how Hurricane Helene’s runoff affected nutrient flux, organic contaminants (specifically six organic contaminants: malathion, atrazine, nicotine, naphthalene, acenaphthene, and pyrene), and microbial composition.

These six organic contaminants showed elevated concentrations in post-hurricane sampling. These higher concentrations of contaminants can be attributed to stormwater and surface runoff from the surrounding areas and intensified water mixing and atmospheric deposition triggered by the hurricane event. Early post-hurricane findings on nutrient levels, such as a sharp increase in phosphate levels from 0.03 ppm to 0.83 ppm within 48 hours, also highlight the urgency of capturing and analyzing these rapid shifts.

By investigating how hurricanes intensify the transport of these compounds and disrupt the watershed’s biogeochemical cycles, this project aims to provide valuable insights into nutrient dynamics, pollutant mobilization, and microbial community changes.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.