A major dam in southern Ukraine has collapsed, flooding villages, endangering crops in the country’s breadbasket and threatening drinking water supplies as both sides in the war scrambled to evacuate residents and blamed each other for the destruction.
Ukraine accused Russian forces of blowing up the Kakhovka dam and hydroelectric power station, built in the 1950s on the Dnieper River in an area that Moscow has controlled for more than a year.
Russian officials blamed Ukrainian bombardment in the contested area, where the river separates the two sides.
It was not possible to reconcile the conflicting claims.
Russian and Ukrainian officials used terms like “ecological disaster” and “terrorist act” to describe the torrent of water gushing through the broken dam, whose reservoir is one of the world’s largest.
Ukrainian President Volodymyr Zelensky called it “the largest man-made environmental disaster in Europe in decades”.
UN secretary-general Antonio Guterres called it a “monumental humanitarian, economic and ecological catastrophe” and “another devastating consequence of the Russian invasion of Ukraine”.
The environmental and social consequences quickly became clear as homes, streets and businesses flooded downstream and emergency crews began evacuations, officials monitored water for cooling systems at the Zaporizhzhia nuclear plant, and authorities expressed concern about drinking water supplies in both Ukrainian and Russian-controlled areas.
In the downstream city of Kherson, a woman who gave her name only as Tetyana waded through thigh-deep water to reach her flooded house and rescue her dogs.
They were standing on any dry surface they could find but one pregnant dog was missing.
“It’s a nightmare,” she kept repeating, declining to give her full name.
Both Russian and Ukrainian authorities brought in trains and buses to move residents to safety.
About 25,000 people in Russian-controlled areas and 17,000 in Ukrainian-held territory should be evacuated, Ukraine’s deputy chief prosecutor Viktoriia Lytvynova said on Ukrainian television.
Neither side reported any deaths or injuries.
A satellite photo on Tuesday morning by Planet Labs PBC analysed by The Associated Press showed a large part of the dam’s wall, more than 600 metres (over 1,900ft), missing.
The dam break, long feared by both sides, added a stunning new dimension to Russia’s war, now in its 16th month.
Ukrainian forces were widely seen to be moving forward with a long-anticipated counteroffensive in patches along more than 1,000 kilometres (621 miles) of the front line in the east and south.
It was not immediately clear why either side might destroy the dam, and its collapse might have resulted from gradual degradation.
Both Russian-controlled and Ukrainian-held lands were at risk.
Russian defence minister Sergei Shoigu claimed that Ukraine destroyed the dam to prevent potential Russian attacks in the Kherson region after what he alleged was a failed Ukrainian counteroffensive.
He claimed Ukraine had lost 3,715 troops and 52 tanks since Sunday, and – in a rare acknowledgment of Russia’s own losses – said 71 Russian troops were killed and 210 wounded.
Ukraine followed its standard practice of not commenting on its casualties.
Mr Zelensky told reporters his government had information about Russia mining the dam last year, so “there may come a moment when an explosion occurs”.
Other Ukrainian officials alleged Russia blew up the dam to hinder Kyiv’s counteroffensive, even though observers note that crossing the broad Dnieper would be extremely challenging.
Other sectors of the front line are more likely avenues of attack, analysts say.
Nigel Gould-Davies, a senior fellow for Russia and Eurasia at the International Institute for Strategic Studies, said the alleged Russian destruction of the dam is “a profoundly defensive measure” showing “the lack of confidence in Russia’s longer-term prospects” in the war.
Experts have previously said the dam was in disrepair, which could also have led to the breach.
David Helms, a retired American scientist who has monitored the reservoir since the war began, said in an email it was not clear if the damage was deliberate or simple neglect from Russian forces occupying the facility.
But Mr Helms also noted a Russian history of attacking dams.
Underscoring the global repercussions, wheat prices jumped 3% after the collapse.
It is unclear whether the surge in wheat prices was due to a real threat of floodwaters destroying crops.
Ukraine and Russia are key global suppliers of wheat, barley, sunflower oil and other food to Africa, the Middle East and parts of Asia.
Authorities, experts and residents have expressed concern for months about water flowing through – and over – the Kakhovka dam.
After heavy rains and snow melt last month, water levels rose beyond normal, flooding nearby villages.
Satellite images showed water washing over damaged sluice gates.
Mr Zelensky alleged Russian forces set off a blast inside the dam structure at 2.50am (2350 GMT Monday) and said about 80 settlements were in danger.
Kremlin spokesman Dmitry Peskov called it “a deliberate act of sabotage by the Ukrainian side … aimed at cutting water supplies to Crimea”.
White House officials were trying to assess potential impacts of the dam collapse and were looking to see what humanitarian assistance can be provided to Ukrainians being displaced, according to a US official.
Both sides warned of a looming environmental disaster.
Ukraine’s Presidential Office said some 150 metric tons of oil escaped from the dam machinery and that another 300 metric tons could still leak out.
Andriy Yermak, the head of Ukraine’s President’s Office, posted video showing the flooded streets of Russian-occupied Nova Kakhovka, a city in the Kherson region where about 45,000 people lived before the war.
Ukraine’s Interior Ministry urged residents of 10 villages on the Dnieper’s right bank and parts of the city of Kherson to gather essential documents and pets, turn off appliances, and leave, while cautioning against possible disinformation.
The Russian-installed mayor of Nova Kakhovka, Vladimir Leontyev, said the city was being evacuated as water poured in.
Ukraine’s nuclear operator Energoatom said via Telegram that the damage to the dam “could have negative consequences” for the Zaporizhzhia nuclear power plant, which is Europe’s biggest, but wrote that for now the situation is “controllable”.
The UN’s International Atomic Energy Agency reported “no immediate risk to the safety of the plant”, which has been shut down for months but still needs water for its cooling system.
It said the rate of the drop in the dam’s reservoir level increased from five centimetres (2in) to nine centimetres (3.5in) an hour and could be depleted in a couple of days.
The Zaporizhzhia power plant has alternative sources of water, including a large pond that can provide water “for some months”, according to the IAEA.
Ukrainian authorities have previously warned that the dam’s failure could unleash a volume of water estimated as nearly equivalent to that of the Great Salt Lake in the United States, flooding Kherson and dozens of other areas where thousands live.
Mohammad Heidarzadeh, from the University of Bath’s Department of Architecture and Civil Engineering, said the Kakhovka dam is one of the world’s biggest in reservoir capacity, 90 times bigger than the UK’s largest, Kielder dam in Northumberland.
The World Data Centre for Geoinformatics and Sustainable Development, a Ukrainian non-governmental organisation, estimated that nearly 100 villages and towns would be flooded, predicting that the water level would start dropping within a week.
Mykhailo Podolyak, a senior adviser to Mr Zelensky, said “thousands of animals and ecosystems will be destroyed in the next few hours”.
Online video showed water inundating a long road; another showed a beaver scurrying for high ground.
The incident also drew international condemnation, including from German Chancellor Olaf Scholz and Nato secretary-general Jens Stoltenberg, who said the “outrageous act … demonstrates once again the brutality of Russia’s war in Ukraine”.
Ukraine controls five of the six dams along the Dnieper, which runs from its northern border with Belarus down to the Black Sea and is crucial for the country’s drinking water and power supply and that of Russian-occupied Crimea.
Ukraine’s state hydro power generating company said the dam’s power station “cannot be restored”.
Ukrhydroenergo also claimed Russia blew up the station from inside the engine room.
Ukraine and Russia have previously accused each other of attacking the dam.