A torrent of water burst through a huge dam on the Dnipro River that separates Russian and Ukrainian forces in southern Ukraine on Tuesday, flooding a swathe of the war zone and forcing villagers to flee.
Ukraine and its Western allies accused Russia of blowing up the dam in a deliberate war crime. The Kremlin said it was Ukraine that had sabotaged the dam, to distract attention from a counteroffensive Moscow claims is faltering. Some Russian-installed officials said the dam had burst on its own.
Neither side offered immediate public evidence of who was to blame. The Geneva Conventions explicitly ban targeting dams in war, because of the danger to civilians posed by destruction of such “works and installations containing dangerous forces”.
By mid-morning in the city of Kherson on the Ukrainian-held side, a pier on a tributary of the Dnipro had already been submerged by the surge climbing the banks.
“The water level has so far risen one metre,” resident Oleksandr Syomyk told Reuters. “We’ll see what happens next but we hope for the best.”
The Nova Kakhovka dam supplies water to a swathe of southern Ukraine’s agricultural land, including the Russian-occupied Crimean peninsula, as well as cooling the Russian-held Zaporizhzhia nuclear plant. The vast reservoir behind it is one of the main geographic features of southern Ukraine, 240 km (150 miles) long and up to 23 km (14 miles) wide.
A swathe of countryside lies in the flood plain below, with villages on the Russian-held southern bank seen as particularly vulnerable.
The destruction of the dam creates a new humanitarian disaster in the centre of the war zone and transforms the front lines just as Ukraine is unleashing a long-awaited counteroffensive to drive Russian troops from its territory.
Russia has controlled the dam since early in the war, although Ukrainian forces recaptured the northern side of the river last year. Both sides had long accused the other of planning to destroy it.
“Russian terrorists. The destruction of the Kakhovka hydroelectric power plant dam only confirms for the whole world that they must be expelled from every corner of Ukrainian land,” President Volodymyr Zelenskiy wrote on the Telegram messaging app.
Russians had “carried out an internal detonation of the structures” of the dam. “About 80 settlements are in the zone of flooding,” he said on Telegram.
NATO’s Secretary-General Jens Stoltenberg called it “an outrageous act, which demonstrates once again the brutality of Russia’s war in Ukraine”.
Kremlin spokesman Dmitry Peskov told a regular news briefing: “We can state unequivocally that we are talking about deliberate sabotage by the Ukrainian side.”
“Apparently, this sabotage is also connected with the fact that having started large-scale offensive actions two days ago, now the Ukrainian armed forces are not achieving their goals, these offensive actions are faltering,” he added.
Earlier, Russian-installed officials had given conflicting accounts, some saying the dam had been hit by Ukrainian missiles overnight, others saying it had burst on its own due to earlier damage.
The U.N. nuclear watchdog said the Zaporizhzhia power plant should have enough water to cool its reactors for “some months” from a separate pond located above the reservoir, and called for the pond to be spared.
The water level at the town immediately adjacent to the breached dam could rise by up to 12 metres, its Russia-installed mayor, Vladimir Leontyev, said on Telegram.
Video showed water surging through the remains of the dam – which is 30 metres (yards) tall and 3.2 km (2 miles) long.
Some 22,000 people living across 14 settlements in Kherson region are at risk of flooding, Russia’s RIA news agency quoted the Moscow-installed head of the region as saying. Kherson is one of five Ukrainian regions Moscow claims to have annexed.
The Russian-installed governor of Crimea, Sergei Aksyonov, said there was a risk that water levels in the North Crimea Canal, which carries fresh water to the peninsula from the Dnipro river, could fall. Crimea, which Russia has held since 2014, had sufficient water reserves for the moment, and the level of risk would become clear in coming days.
The dam breach came as Ukraine prepares its long-awaited counteroffensive to drive Russian forces from its territory, using newly supplied Western tanks and armoured vehicles.
Moscow has said the Ukrainian offensive began on Sunday and has claimed to have repulsed Ukrainian advances.
Kyiv has mostly kept strict silence about it, although Zelenskiy hinted at successes. In an evening address before the dam broke, he hailed “the news we have been waiting for” claiming forward moves around Bakhmut, a ruined city Russia captured earlier this month in its first major claimed victory in nearly a year.
Russia also launched a fresh wave of overnight air strikes on Kyiv. Ukraine said its air defence systems had downed more than 20 cruise missiles on their approach to the capital.
The Shebekino district of Russia’s Belgorod region near the Ukrainian border came under renewed shelling on Tuesday, local authorities said. Anti-government Russian fighters based in Ukraine claim to have infiltrated the area.
Russian President Vladimir Putin sent troops into Ukraine on Feb. 24 last year in what the Kremlin expected to be a swift operation, but its forces suffered a series of defeats and regrouped in the country’s east.