This dataset presents a comprehensive floristic inventory and trait-based analysis of vascular plants colonizing the exposed bed of the Kakhovka Reservoir following its drainage in June 2023. Compiled from seven targeted field expeditions, iNaturalist observations, and GBIF occurrences, the data covers key localities across the Kherson, Zaporizhzhia, and Dnipropetrovsk regions. Each entry is enriched with standardized ecological and biomorphological attributes, including Didukh’s ecological scales and simplified LifeVeg.EU traits, providing a robust empirical foundation for studying primary succession and large-scale riparian renaturalization.