On June 24, 2024, following three days (17-20 cm) of rain, floodwaters avulsed around the western edge of the 114-year-old Rapidan Dam on the Blue Earth River (BER). This event resulted in the river, which had been dammed since 1910, returning to a free-flowing state. To understand how the system has changed, we characterized river responses by comparing monthly satellite imagery with digitized banklines, a reconstructed surveyed surface from 1911 with digitized banklines, and one pre-failure elevation (April 05, 2024) and post-failure elevation (November 07, 2024) surface. Post-failure low-flow imagery showed the transition of the BER from a meandering, single-threaded channel to a braided stream, highlighting the high sediment load of freed reservoir material. Upstream of the dam, floodwaters and knickpoint migration had obliterated multiple vegetated islands. Hillslope failure, bank failure, and channel migration were prevalent throughout both the upstream and downstream reaches, as the system relaxed and adjusted towards its new baselevel. This change from a constrained to highly dynamic system helps illustrate the rapid nature of post-failure fluvial readjustment, a concern exacerbated by anthropogenic climate change-induced regional precipitation increases.
