The destruction of the Nova Kakhovka dam in 2023, under Russian control during the ongoing war, has led to a dramatic ecological transformation in southern Ukraine. The breach unleashed catastrophic flooding, killing an unknown number of people and displacing up to one million from safe drinking water sources. But two years on, scientists are observing a surprising outcome: large-scale natural regeneration in the former reservoir basin.

The drained Kakhovka reservoir—once covering 2,155 square kilometres—has given rise to dense vegetation, wetlands and a rapidly growing floodplain forest. Researchers from the Ukrainian War Environmental Consequences Work Group (UWEC) report that as many as 40 billion tree seeds have sprouted, marking what could become the largest floodplain forest in Ukraine’s steppe zone.

Endangered sturgeon have returned to spawn, and native mammals like wild boar are reappearing. The area known as Velykyi Luh, or the Great Meadow, is experiencing spontaneous ecological renewal for the first time since it was submerged by Soviet damming in 1956.

However, the revival is threatened by environmental risks. Scientists estimate that 1.5 cubic kilometres of polluted sediment—containing heavy metals—were released from the reservoir floor. This contamination, difficult to monitor due to ongoing conflict and landmines, is described as a “toxic timebomb” in a 2025 report published in Science.

Despite uncertainties, experts say 80% of ecosystem functions lost to the dam could be restored within five years. While Ukraine’s state energy company plans to rebuild the dam, ecologists warn that doing so would erase a unique opportunity for large-scale freshwater restoration and biodiversity recovery in Europe.