Factbox: What is the Kakhovka dam in Ukraine - and what happened?

A major dam and hydro-electric power plant in Russian-occupied southern Ukraine suffered a collapse early Tuesday, prompting mass evacuations and fears for large-scale devastation as Ukraine accused Moscow’s forces of committing an act of “ecocide.”

Residents downstream from the Nova Kakhovka dam on the Dnipro River in Kherson were told to “do everything you can to save your life,” according to the head of Ukraine’s Kherson region military administration, as video showed a deluge of water gushing from a huge breach in the dam.

The critical Nova Kakhovka dam is the largest reservoir in Ukraine in terms of volume. It’s the last of the cascade of six Soviet-era dams on the Dnipro River, a major waterway running through southeastern Ukraine. There are multiple towns and cities downstream, including Kherson, a city of some 300,000 people before Moscow’s invasion of its neighbor.
Here is what we know about the crisis.

What happened?
Two videos posted to social media and geolocated by CNN showed the destroyed dam wall and fast-moving torrents of water flowing out into the river. Multiple buildings at the entrance to the dam were also heavily damaged.

It is unclear what caused the dam to collapse, which came as Ukraine geared up for a widely anticipated counter-offensive. Both Ukrainian and Russian officials said the dam collapsed in an explosion and are blaming each other for it.
The Ukrainian military intelligence said an explosion occurred at 2:50 a.m. local time on Tuesday (7.50 p.m. ET Monday), when “Russian terrorists carried out an internal explosion of the structures of the Kakhovka hydro-electric power plant.”

Meanwhile, the Russian-installed mayor of Nova Kakhovka, Vladimir Leontiev, initially denied the dam had collapsed in an interview with Russian state media RIA Novosti, calling it “nonsense.” He later confirmed the destruction of parts of the dam in what he called “a serious terrorist act” but said there was “no need to evacuate.”

CNN was not immediately able to verify the claims made by Ukrainian and Russian officials.

The Kremlin on Tuesday rejected the accusations. In his regular call with journalist Dmitry Peskov said the attack was “planned and carried out by order received from Kyiv, from the Kyiv regime.”

Peskov, the Kremlin’s spokesperson, said Russia “unequivocally” believes the attack was “a deliberate sabotage” by Ukraine, aiming to “deprive Crimea of water” and that the Ukraine’s caused the damage because “having launched large-scale offensive operations two days ago, now the Ukrainian Armed Forces are not achieving their goals. These offensive actions are choking.”

What are the consequences?
The dam holds back around 18 cubic kilometers of water in the Kakhovka Reservoir, about equal to the Great Salt Lake in the US state of Utah. Mykhailo Podolyak, a senior Ukrainian official, said the water level in the reservoir was falling “rapidly, about 15 centimeters per hour.

Enter your email to sign up for CNN's "Meanwhile in China" Newsletter.
close dialog
What’s happening in China and what does it mean for the rest of the world?

The damage appears to be vast and the potential devastating impact – both upstream and downstream – is worrying. Multiple towns and cities downstream from the dam are at risk of severe flooding and Podolyak had previously urged citizens to “collect your documents and most needed belongings” and wait for evacuation buses. “I ask you to do everything you can to save your life. Leave the dangerous areas immediately,” he added.

The country’s President Volodymyr Zelensky said on Telegram that there were “about 80 settlements in the flood zone” and that he has ordered evacuations. The cities include Kherson, a city that was home to some 300,000 people before Moscow’s invasion.