The Nova Kakhovka dam in the Russian-occupied southern Ukraine, a major hydro-electric power plant, collapsed, leading to widespread evacuations and possible large-scale devastation. The cause of the collapse remains unclear, with both Ukrainian and Russian officials attributing it to an explosion, each blaming the other party. The dam, holding around 18 cubic kilometers of water, poses a significant ecological and environmental risk. There is further concern about the potential impact on the Zaporizhzhia nuclear power plant upstream from the dam. 

Key Points: 

1. The Nova Kakhovka dam is the largest reservoir in Ukraine, being the last of the cascade of six Soviet-era dams on the Dnipro River. Multiple towns and cities downstream are at risk of severe flooding due to its collapse. 
2. Both Ukrainian and Russian officials claim that an explosion led to the dam’s collapse, blaming each other for it. Satellite imagery suggests damage to the dam’s structure days before the collapse, but the direct link is yet to be confirmed. 
3. The dam’s collapse could have far-reaching ecological and environmental consequences. An expert warns that the dam’s failure can have long-term impacts not only for Ukraine but also for neighboring countries and regions. 
4. The impact of the collapse on the Zaporizhzhia nuclear power plant, Europe’s largest nuclear power station, is a significant concern. The reservoir supplies crucial cooling water to the plant, but authorities suggest that the cooling pond remains full and sufficient for the plant’s needs. 
5. The geopolitical implications of the dam collapse are also considerable, as it may influence the course of the ongoing conflict between Ukraine and Russia. Ukrainian officials suggest that the dam’s destruction could hinder their planned counter-offensive against Russian forces.

Source: https://www.cnn.com/2023/06/06/europe/ukraine-nova-kakhovka-dam-breach-intl-hnk/index.html