Critical Dam Destroyed on Front Line in Southern Ukraine

A critical dam and hydroelectric power plant along the front line in southern Ukraine was destroyed on Tuesday, videos verified by The New York Times show, putting thousands of people at risk of flooding and raising questions about safety at a nuclear plant upstream.

It was not immediately clear who was responsible for the attack on the Kakhovka dam and electric plant, which lies along the Dnipro River and is under Russian control. President Volodymyr Zelensky blamed “Russian terrorists” and Ukrainian officials said Russian forces had caused an explosion at the facility. The Kremlin’s spokesman, Dmitry S. Peskov, blamed the destruction of the dam on Ukrainian forces, calling in a “sabotage” attack.

The disaster, which came a day after American and Russian officials said a planned Ukrainian counteroffensive had begun, sent a torrent of water gushing through the damaged sections of the dam and power plant, according to footage. Most experts think the counteroffensive will be east of the river, but the destruction of the dam could divert both sides’ attention and resources.

The barrier, which is located on the Dnipro River and holds back a body of water the size of the Great Salt Lake in Utah, maintains a reservoir that supplies water for drinking, agriculture and the cooling of the Zaporizhzhia Nuclear Power Plant, Europe’s largest nuclear power station.

The United Nations’ nuclear watchdog, the International Atomic Energy Agency, said that it was “closely monitoring” the situation at the nuclear plant but that there was “no immediate nuclear safety risk.”

Security of the dam, the second largest of the cascade of six dams on the Dnipro River and a vital source of water and power, had been a continuing concern during the war, with both sides accusing the other of plotting to destroy it.

Here are other developments:

Videos and images on social media appeared to show flooding already underway in communities downstream from the Kakhova dam, and streets filling with rising water. Mr. Zelensky convened his National Security Council and local Ukrainian officials began evacuating thousands of residents.
About 16,000 people are in the “critical zone” on the Ukrainian-controlled west bank of the Dnipro River, said Oleksandr Prokudin, the Ukrainian regional military administrator. The dam could flood about 80 settlements, officials said. Civilians were being evacuated from flood zones, which include parts of the city of Kherson and 10 villages.
Emergency crews were racing to southern Ukraine from Kyiv, the head of the state emergency service, Serhiy Kruk, said in a statement. Vehicles designed to be driven through floodwaters have been sent and generators, mobile water treatment plants, water trucks and other equipment were also on their way.

Marc Santora, Maria Varenikova and Anna Lukinova contributed reporting.