Mapping the Flooding From the Dam Breach in Southern Ukraine

Extensive flooding inundated villages and swept away structures after a dam was destroyed in southern Ukraine on Tuesday, according to local officials and imagery of the aftermath.

With the waters still rising and reliable information hard to come by — especially from Russian-held areas east of the Dnipro River — the full magnitude of the threat was difficult to gauge.

But some towns are already submerged, and more than 40,000 people may be in the path of the flooding on both sides of the river, according to the deputy prosecutor general of Ukraine.

The river is not expected to crest until Wednesday morning.

In the town of Antonivka, about 40 miles downriver from the Kakhovka dam, residents looked on in horror at the roiling coffee-colored floodwaters released by its destruction. People could be seen wading about swamped front yards rescuing pets and belongings. About 4,000 residents remained there before the flooding on Tuesday, out of a prewar population of about 13,000.

Local officials told Russian state media that the small town of Oleshky, on the Russian-held side, was almost completely flooded, and a nearby highway could be seen underwater in videos shared on social media. Residents in fishing villages along the river and in low-lying neighborhoods of Kherson evacuated by bus and train on Tuesday.

The dam holds back the Kakhovka Reservoir, a body of water the size of the Great Salt Lake in Utah that provides drinking water and water for the area’s rich farmland. Ukraine and Russia blamed each other for the attack on the dam, which is in Russian-held territory.

In Nova Kakhovka, the city immediately next to the destroyed dam, the City hall and the Palace of Culture were inundated.

The Zaporizhzhia Nuclear Power Plant, upstream from the dam, also relies on water from the reservoir to cool its reactors and spent fuel. The facility was not at immediate risk of meltdown as a result of the dam’s destruction, according to The International Atomic Energy Agency, the U.N.’s nuclear watchdog.