THE INFLUENCE OF DAMS ON THE DISCHARGE AND FLOOD FREQUENCY OF THE CHATTAHOOCHEE, FLINT, AND APALACHIOCOLA RIVERS

Many large dams were constructed in the United States during the twentieth century, including within the Apalachicola-Chattahoochee-Flint (ACF) watershed in the southeastern region. Dams help to control moderate flooding, but can be limited in managing larger flood events. The magnitude of peak flows may be correlated with climate change and/or urbanization. The Chattahoochee and Flint Rivers have different degrees of dam management; the Chattahoochee River has thirteen dams and the Flint River has only three dams. The Apalachicola River has no dams. The goal of this research is to analyze the influence of dams on the flood frequency and discharge of the three rivers. We propose that due to a higher degree of dam management on the Chattahoochee River, there will be a decreased flood frequency and magnitude on this river compared to the Apalachicola and Flint Rivers. Peak flow data are collected from USGS gauging stations. We use the generalized extreme value distribution to standardize the flood frequencies of pre-dam and post-dam peak flows. Additionally, the flood frequencies and magnitudes will be compared between the Apalachicola and Flint Rivers to investigate the effect of anthropogenic disturbances within the instrumented record, such as land-use change and climate change. Lastly, the impacts of major hurricanes, such as Hurricane Michael in 2018 and Hurricane Helene in 2024, will be analyzed across the hydrographs of the three rivers. Understanding the conditions that result in high flows will inform and help improve future river management in the ACF watershed.