The breach of the Kakhovka Dam in Ukraine during the Russia-Ukraine war caused not only immediate devastation but also unleashed a "toxic time-bomb" of pollutants threatening to poison ecosystems and water supplies for years to come, a new study co-authored by a University of Iowa engineering professor has found. The study serves as a stark warning about the social, economic, and environmental consequences of using water infrastructure as a weapon of war as well as risks associated with aging dams. 

When the Soviet era dam collapsed on June 6, 2023, 16.4 cubic kilometers of water flushed out carrying approximately 83,000 tons of heavy metals like nickel, cadmium, and lead accumulated over decades from local factories. Scores of people died, up to 1 million lost access to drinking water, and entire ecosystems were destroyed.

News reports have highlighted examples of recovery, but those stories mask a serious underlying threat, according to the study by more than 25 scholars, including George S. Constantinescu, a UI professor of civil and environmental engineering who is renowned in the fields of hydraulics and computational fluid dynamics.

“Although media attention has focused on the immediate impacts of flooding on society, politics, and the economy, our results show that toxic contamination within newly exposed sediments of the former reservoir bed poses a largely overlooked long-term threat to freshwater, estuarine, and marine ecosystems,” the authors wrote in the paper published in the March issue of Science, a leading general science journal.  

The authors, led by Oleksandra Shumilova of the Leibniz-Institute of Freshwater Ecology and Inland Fisheries, measured and modeled data using remote sensing techniques to forecast the reach of impact of the breach and the potential timetable for recovery. 

With less than 1% of the contaminated sediment washed downstream, seasonal floods pose a significant risk. In spring 2024, contaminated floodwaters inundated nearly 900 square kilometers. The most critical concern is bioaccumulation, where these heavy metals can build up in the food chain, potentially causing long-term health risks. 

As the conflict continues, the Kakhovka Dam's destruction stands as a powerful reminder of the hidden, long-lasting environmental impacts of warfare—a message Constantinescu and his colleagues are communicating to the global scientific community. 

The full paper is available here: https://www.science.org/doi/10.1126/science.adn8655.