The collapse of a critical dam along the Ukrainian front line on Tuesday is expected to have wide reaching implications for Russia’s war on the country, affecting energy, food and water supplies, displacing a major civilian population and raising the risk of a nuclear disaster.  

Drone footage published on Tuesday captured water rushing through the remains of the Nova Kakhovka reserve and dam in Russian-held Ukraine, sparking mass evacuations, accusations of blame from both sides and emergency meetings of Ukrainian and Western officials.

Ukraine has accused Russia of blowing up the Soviet-era dam “in panic,” as Kyiv appears to be starting its long-expected counteroffensive, while the Kremlin has implied that Ukraine is to blame and that it was a terrorist attack. 

The United States said it was looking into the collapse and “closely monitoring the impacts” but “cannot say conclusively what happened at this point,” according to White House National Security Council spokesperson John Kirby. 

The dam, a source of concern for months, is seen as critical to both sides as it supplies water for the majority of southeastern Ukraine, including the Zaporizhzhia nuclear power plant and the Russian-annexed Crimean peninsula. 

Here are potential impacts to the war and beyond.  

Disruption to Ukrainian counteroffensive operations 

U.S. and Western officials this week have noted signs of the start of Ukraine’s long-planned summer counteroffensive to push Kremlin forces from the country, starting with Ukraine-launched attacks in the eastern Donetsk region over the weekend. 

The preliminary attacks, which were first seen at least two weeks ago, have quickly picked up in the past 48 hours with Ukrainian artillery strikes and ground attacks in the southern Donetsk region.  

The recent dam collapse could complicate things, however, as it is likely to flood the Dnipro River as well as bridges and roads in the area, making it more difficult for Ukrainian troops to cross the waterway to attack Russian positions on the other side.  

Mykhailo Podolyak, senior adviser to Ukrainian President Volodymyr Zelensky, said the collapse would “create obstacles for the offensive actions of the Ukrainian Armed Forces.” 

Asked what effects, if any, the United States thinks the dam collapse will have on Ukraine’s summer counter-offensive, Kirby declined to comment as “it’s too soon to know.” 

In addition, significant humanitarian issues caused by the dam’s destruction will need to be addressed, siphoning resources from the Ukrainian government and the war effort to handle the effects of the catastrophe.  

The dam’s position along Ukraine’s front line has previously caused strife in the war, including in August when a Ukrainian artillery strike struck a bridge along the dam. The larger structure avoided any damage in that attack. 

And in November Russian forces bombed a portion of the road above the dam’s gates, an explosion that narrowly avoided damaging the dam ‘s infrastructure, according to The New York Times.  

Nuclear risk 

In addition to possibly upending the Ukrainian counteroffensive, the collapse of Nova Kakhovka could also mean a new risk to the Zaporizhzhia power plant, to which it supplies water.  

Zaporizhzhia, which sits northeast of the dam and serves as Europe’s biggest nuclear power plant, is currently being “closely” monitored by the UN’s nuclear watchdog, the International Atomic Energy Agency.  

The dam is crucial to the plant, as its reservoir supplies the water to cool its six nuclear reactors, using that heat to run electrical generators. The water also serves to cool spent fuel and emergency diesel generators, needed should the external power fail. 

The IAEA on Tuesday sought to alleviate fears of impending disaster, saying there was “no immediate nuclear safety risk” to the plant with the dam’s destruction. 

“There are a number of alternative sources of water. A main one is the large cooling pond next to the site that by design is kept above the height of the reservoir,” IAEA Chief Rafael Grossi said in a statement. Water from the pond should be able to provide enough water for “some months,” Grossi added. 

And Patrick Regan, a professor at the University of Surrey specializing in nuclear meteorology, said while the dam explosion is “deeply concerning in terms of flooding, loss of hydroelectric power and water supply issues,” there’s still only limited risks regarding release of radioactive materials from Zaporizhzhia. 

Should water be cut off, there’s the potential fuel rods could overheat and melt, but that “does not seem to be an issue at present,” Regan said in a statement. 

“The situation clearly needs continued and accurate monitoring, but the first health problems surely arise as a result of flooding of homes and farms from the destroyed dam,” he added. 

This general view shows a partially flooded area near The Antonovskiy Bridge (REAR) on the outskirts of Kherson, on June 6, 2023, following damage sustained at Kakhovka hydroelectric dam. A Russian-held dam in southern Ukraine was damaged on June 6, with Kyiv and Moscow accusing each other of blowing it up while locals were forced to flee rising waters. The dam was partially destroyed by “multiple strikes”, Moscow-installed authorities claimed just as expectations were rising over the start of Ukraine’s long-awaited offensive. (Photo by Oleg TUCHYNSKY / AFP)

Damage to energy and water supplies and environmental risks 

Nova Kakhovka is the final of six dams that sit north to south along the Dnipro River, the longest river in Ukraine. 

The dam — which creates the largest reservoir in Ukraine in terms of volume, holding about as much water as the Great Salt Lake in Utah — is used to supply hydroelectric stations, several major irrigation systems, industrial plants such as Zaporizhzhia, freshwater fish farms and several major canals in southeastern Ukraine, including in Russian-occupied Crimea. 

Its collapse could “very well have a devastating impact on Ukraine’s energy security, and it will certainly have an impact on Ukraine’s canal system,” Kirby told reporters. 

“The damage to the Ukrainian people and to the region will be significant,” he added.  

European officials had more dire warnings over the incident. 

Zelensky called it “the largest man-made environmental disaster in Europe in decades.”  

And U.N. Secretary-General Antonio Guterres, said it was a “monumental humanitarian, economic and ecological catastrophe” and “another devastating consequence of the Russian invasion of Ukraine.” 

The collapse has also triggered an all-but-certain environmental catastrophe, with Ukrainian officials revealing that roughly 150 metric tons of oil escaped from the dam’s machinery. Another 300 metric tons could still leak, they said, according to The Associated Press.  

Zelensky’s aide, Podolyak, said “thousands of animals and ecosystems will be destroyed in the next few hours.” 

The flooding also stands to endanger crops in the Ukraine’s breadbasket, with wheat prices jumping 3 percent following the dam’s collapse. 

The country, along with Russia, is the key global supplier of wheat, barley and sunflower oil to much of the globe including Africa and the Middle East.

Mass displacement of civilian populations  

Multiple towns and cities sit downstream from the Nova Kakhovka dam, including Kherson, where more than 1,200 people have already been evacuated due to flooding, according to local officials. 

Early dispatches from the areas affected are dire, with more than 1,000 houses in the Ukrainian-held parts of Kherson reportedly already underwater. 

Though neither Ukrainian or Russian controlled areas have reported any deaths or injuries, both sides have dispatched trains and buses to move residents to safety, according to the AP. 

And Ukraine’s deputy chief prosecutor Viktoriia Lytvynova, said on Ukrainian television that about 25,000 people in Russian-controlled areas and 17,000 in Ukrainian-held territory should be evacuated. 

Ukraine’s Interior Ministry, meanwhile, told residents of 10 villages to grab essential documents and pets, turn off home appliances and leave. 

But that appears to be only the beginning effects on civilians caused by the dam’s collapse. 

Kirby said the destruction has “triggered massive flooding in Ukraine and resulted in the evacuation of, at the very least, thousands of Ukrainians.” 

He added that “there are casualties, including likely many deaths, though these are early reports, and we cannot quantify them right now.”