On June 24, 2024, following 17-20 cm of precipitation in the preceding three days, floodwaters avulsed around the western edge of the 114-year-old Rapidan Dam on the Blue Earth River. Upstream of the dam, on the interior side of a meander bend, the furious current of the river eroded away a mature floodplain forest, undergrowth, and an average of 5.5 meters of reservoir sediment. This freshly denuded area allowed for numerous plant species to recolonize this area once the flood waters receded.We conducted a “Bioblitz” using the iNaturalist platform, where a group of 9 observers went out and photographed as many plants as possible on an afternoon in August 2025 to study this new growth. Photographs included geotagged location and date/timestamps that iNaturalist uses to provide a suggested species that the user can confirm or provide an alternative suggestion. Crowdsourcing allows other platform users to confirm an interpretation. We assessed the change in plant coverage using PlanetScope satellite imagery (3-meter resolution), biomass using LiDAR and UAS structure-from-motion photogrammetry products, and the different species colonizing the area approximately 14 months after the event. We observed significant plant growth and an increase in coverage and biomass throughout the observation period.
