Kherson under the waves after the destruction of a dam

In one video, a house floats, carried by the current, its elongated roof protruding from the waves like a strange aquatic monster. On another, two stunned grandmothers discover their neighborhood completely flooded. On a third, the Palace of Culture of Nova Kakhovka is half buried in dirty water. Dozens of photos and videos, posted on social networks by residents, reveal to the world, at human height, the disaster that occurred Tuesday morning in southern Ukraine.

At dawn, a huge detonation sounded at the hydroelectric plant located on the outskirts of the town of Nova Kakhovka, on the left bank of the Dnieper, in the Kherson region, making the windows of houses vibrate dozens of kilometers around, according to several witnesses. The explosion dug a wide opening in the plant's dam, pouring torrents of water over entire villages. The plant itself was also damaged.

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On the spot, a Russian official announced Tuesday afternoon that the water level of the reservoir was dropping, at a rate of 35 cm per hour. At the same time, the Ukrainian authorities claimed that 150 tons of engine oil had spilled into the Dnieper River, that 24 localities were flooded, at least 600 homes were devastated in Nova Kakhovka alone, and that "about a thousand" civilians had been evacuated from the area. Already hostages to Moscow's war in Ukraine, hundreds of families are now victims of a humanitarian catastrophe.

'Hundreds of thousands of victims'

The impressive facility — the dam alone stands 30 meters high and stretches for 3.2 kilometers — is in an area currently controlled by the Russians, on the Dnieper River, which flows from north to south of Ukraine. Built in 1956 during the Soviet era, the Nova Kakhovka Hydroelectric Power Plant is one of the most important energy facilities in the country.

Retaining 18 million cubic meters of water, it produces electricity for more than three million Ukrainians and is a key device in the country's energy grid. It also supplies water to the Crimean peninsula, annexed by Russia in 2014, as well as the Zaporizhzhia nuclear power plant, the largest in Europe (now controlled by Moscow), which also draws water from the reservoir necessary for cooling its reactors.

The explosion at the Nova Kakhovka hydroelectric power plant will have devastating consequences, including a water shortage in Crimea that will last for decades.

Mustafa Nayyem, Director of the State Infrastructure Agency

According to the director of the state agency for infrastructure, Mustafa Nayyem, the destruction of the dam endangers more than 80 localities, and the floods could cause "hundreds of thousands of victims". "The explosion at the Nova Kakhovka hydroelectric power plant will have devastating consequences, including a decades-long water shortage in Crimea, the irreversible disruption of hundreds of thousands of lives, and the risk of drowning for thousands," Nayyem said.

Cutting off the inflow of water into Crimea

Both sides accuse each other of blowing up the dam. Volodymyr Zelensky immediately pointed the finger at "Russian terrorists". The special ambassador of the president, Anton Korynevych, also condemned, during a speech at the International Criminal Court, the action of a "terrorist state": Kiev and Moscow found themselves, that day, before international justice in The Hague, in the context of a case brought by Ukraine in 2017 and then coupled with another request, following the Russian invasion of February 2022, by which Ukraine accuses Russia of planning genocide.

From Kiev, the adviser to the Ministry of the Interior, Anton Gerashchenko, also hammered that the destruction of the dam is "another proof of Russia's genocidal policy towards the Ukrainians".

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Many members of Ukrainian civil society refer to "ecocide", a term included in the country's penal code since 2001 and which implies a desire to cause major damage to one or more ecosystems. For about a year, Ukraine has been trying to identify acts of "ecocide" committed on its territory by enemy forces.

For their part, the Russian authorities initially denied that the explosion had taken place, before evoking a sabotage operation by Ukrainian forces aimed at cutting off the flow of water into occupied Crimea and diverting the world's attention from a probable failure of their counter-offensive, expected for several months. Moscow announced that Russian investigators would conduct an investigation to identify the origin of the explosion.

'Violation of international law'

The many international reactions leave little doubt about the opinion of Western leaders as to who ordered the disaster. European Council President Charles Michel said Russia should be held accountable, calling it a "war crime". "Russia's attacks on critical civilian infrastructure have reached an unprecedented level," EU foreign policy chief Josep Borrell said, stressing that the act "could constitute a violation of international law."

"The Nova Kakhovka dam is a particularly strong structure. But the Ukrainians do not have in their arsenal enough to carry out a strike powerful and precise enough to destroy it in this way, "says Colonel Michel Goya, a specialist in military issues. "Moreover, in view of the images, we can conclude a very vertical explosion, from bottom to top, which suggests that several tons of explosives were placed under the dam, in the middle of the area occupied by the Russians," concludes the co-author of The Bear and the Fox. Immediate history of the war in Ukraine.

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The strategic site was notoriously a point of concern. Since October, the Ukrainian authorities had accused the Russians of having undermined the facility and feared that Moscow could deliberately damage it.

On Tuesday, experts agreed that the destruction inflicted on the structure could not be plugged in the short term. The floods therefore threaten to complicate Ukrainian operations in much of the south, including the passage to the east bank of the Dnieper. The colossal logistical challenge of the humanitarian crisis and the damage to the plant and dam is as much a blow to Kiev as it is a blow to the morale of Ukrainians.