Key elements of civilian infrastructure along the Dnipro River in southern Ukraine have been impacted by the June 6 destruction of the Kakhovka Dam, researchers with the Yale School of Public Health’s Humanitarian Research Lab (HRL) say in a new report.

Using commercially available satellite imagery and synthetic aperture radar, the researchers identified five schools, three hospitals, seven power and energy facilities, and 21 crop storage facilities that have been impacted by floodwaters encompassing 520 square kilometers of southern Ukraine. At least 51 towns and villages on the banks of the Dnipro River have been affected, the researchers said.

The Kakhovka Hydroelectric Dam sits on one of the world’s largest reservoirs, one that supplies critical irrigation for farmland in the region, which has been described as the breadbasket of Europe. Prior to the war with Russia, Ukraine was one of the world’s leading exporters of corn and wheat. Many under-resourced countries in Africa and the Middle East depend on Ukrainian grain imports. The long-term impact of the flooding on soil nutrients and valuable fertile farmland remains to be seen.

In their report, the researchers say the floodwaters have not only displaced civilians, damaged farmland, cut off water supplies, and destroyed or damaged buildings, they have also swept large amounts of debris downstream. Open-source videos have shown large objects —including a house — floating in the engorged Dnipro River. Toxic industrial chemicals, military material, human and animal waste, and other hazardous materials are almost certainly being displaced and carried to downstream communities, the researchers said. Included in this detritus is unexploded ordinance that could include anti-personnel and anti-tank mines, artillery shells, and the remnants of other explosive devices such as cruise missiles and cluster munitions that have failed to properly detonate. The Halo Trust has documented flooding in at least one minefield resulting from the dam failure and is monitoring the movement of submerged mines, the report said.

The damage caused by the dam’s destruction and its widespread impact on civilians could have signification repercussions, the researcher said.

“If the dam’s destruction was caused by a deliberate explosion, the act would violate the Geneva Convention’s Additional Protocols I and II, which forbid attacks on “installations containing dangerous forces” if such an attack may “release dangerous forces” and cause severe losses among civilians,” the researchers say in their report.

The report does not estimate how many civilians have been impacted by the destroyed dam. Ukraine’s Deputy Prosecutor General has estimated that 40,000 people on both banks of the river need to be evacuated, while the U.S. Department of State has said that as many as 20,000 people may need to be resettled.

The cause of the dam’s catastrophic damage remains under investigation and a point of contention. Russia, which has controlled the dam since the war began, has blamed Ukrainian bombardment for the damage (the dam is located on the war’s frontlines). Ukraine, in return, has blamed Russia for the dam’s collapse and is investigating the incident as a war crime and possible criminal environmental destruction known as “ecocide.” Recent reports by the Associated Press and the New York Times appear to show evidence that Russia was responsible.

The HRL report was produced as part of the Conflict Observatory, an initiative launched by the U.S. Department of State to monitor conditions and humanitarian needs in Ukraine during the war. Maxar Technologies and ICEYE contributed to the report.