KRYVYI RIH, Ukraine—Russian missiles had blown a hole in the dam that sits above this city, sending water rushing through and threatening to inundate tens of thousands of homes.
“It looked like Niagara Falls,” said Oleksandr Vilkul, the city’s top official.
Over the next 24 hours—using dynamite, tons of gravel, temporary barriers and a large concrete block held by a crane—city workers managed to plug the leak and prevent a catastrophic flood.
After Ukrainian forces began retaking swaths of territory in early September, Moscow responded with attacks on Ukraine’s critical civilian infrastructure. The strikes mark a new phase in the war, in which Russia is threatening civilians far from the front lines with flooding and freezing nights with no heat as winter approaches.
Over the past month, Russian artillery has struck power stations in Kharkiv, Zmiiv, Pavlograd and Kremenchuk, which left hundreds of thousands of people in eastern and central parts of Ukraine without power. Moscow hit the dam in Kryvyi Rih, Ukrainian President Volodymyr Zelensky’s hometown, on Sept. 14. Russian strikes knocked out power in the northeastern Kharkiv region, where Ukraine has retaken the most territory, twice more over the past two weeks. Kamikaze drones, which Russia purchased from Iran, have hit both civilian and military targets across Ukraine in recent weeks.
Russia has been hitting Ukrainian infrastructure throughout the war, with more than 4,000 attacks since Feb. 24, according to the Ukrainian Ministry of Infrastructure. The majority of those strikes had some military purpose, according to the ministry.
The latest round of attacks, however, signals a tactical shift following Russian defeats on the ground, said John E. Herbst, a former U.S. ambassador to Ukraine.
“Moscow is clearly unable, in the foreseeable future, to defeat the Ukrainian military. That’s given them additional reason to make life difficult for Ukrainians by going after critical infrastructure,” he said. The strikes have little military value, he said.
Hard-liners in Russia for months have called for their president, Vladimir Putin, to take out critical Ukrainian rail hubs, power stations and water systems, part of their push for a total war in Ukraine. Though the Kremlin has said that it doesn’t target civilians, Mr. Putin has warned that strikes on critical infrastructure could become the norm. “Just recently the Russian armed forces hit some sensitive targets,” said Mr. Putin, speaking two days after the strike on the Kryvyi Rih dam. “Let’s consider these to have been warning strikes. If the situation develops further in the current direction, our response will be more serious.”
The strike in Kryvyi Rih demonstrates the potential for devastation.
The dam holds nearly 11 billion cubic feet of water on a ridge overlooking the city. Around 5 p.m. on Sept. 14, three Russian missiles struck one of the dam’s sluices, the gates that regulate the water level, over the course of several minutes, according to video footage that local officials showed The Wall Street Journal. Water began pouring toward the city.
A former mining engineer in this industrial hub, Mr. Vilkul went up to survey the damage himself. “The situation was critical,” he said. “There was a real threat that two city districts would be fully flooded.”
Two smaller dams downstream also hold back the Inhulets River. Mr. Vilkul, who is head of the city’s military administration, said he called engineers downstream and told them: Blow the dams. The decision let water pass more quickly through the river, instead of continuing to rise.
Still, in just the first two hours after the strikes, the Inhulets River had risen about 10 feet.
Mr. Vilkul said he called industrial companies around the city. “I sent them my geolocation and asked them to bring rocks,” he said. Soon, trucks were arriving full of gravel and dumping it into the reservoir, just in front of the sluice that had been hit.
City workers also found several temporary sluice gates, each about 5 feet tall, which they brought to the top of the dam. Stacked on top of one another, they could plug the hole, in place of the destroyed 25-foot-tall sluice.
But there was a problem, Mr. Vilkul said: They were meant to be installed into still water, not in the middle of what had become a cascade.
What’s more, no one knew if the Russian missile attack was over. Every time air-raid sirens rang out, workers lurched toward cover.
All the while, water kept rising. Lyubov Adamenko, the district head in one low-lying neighborhood of Kryvyi Rih, said that as the night wore on, water seeped into her garden, then into her kitchen. Evacuation buses arrived.
On the street closest to the river, an elderly woman had to be pulled out of her house through a window around 5 a.m., Ms. Adamenko said.
At the top of the dam, engineers worked through the night to slide the temporary sluice gates into place. Because of the rushing water, however, they didn’t fit together properly, and water kept pushing through. So engineers attached a concrete block to a crane and slammed it down on top of the makeshift sluice like a hammer, trying to force the gates tighter together.
By the next morning, Mr. Vilkul said, they had plugged the hole sufficiently to allow water levels in the city to begin to recede. Over the next two days, Mr. Vilkul said, Russian missiles hit the dam eight more times, often damaging the repairs but never undoing them. It took a week to entirely stop the flow out of the damaged sluice, which is now covered with rocks and clay.
Mr. Vilkul, long a prominent member of a pro-Russian party who has become a vocal critic of Moscow since the full-scale invasion began, said the city hadn’t been prepared for this kind of strike.
Around the country, workers at critical infrastructure points are now conducting drills on how to handle attacks of various kinds. With winter coming, Ukrainian officials are particularly preparing to help people survive if gas lines are hit, buying backup generators to set up heating centers if needed.
“The point was just to terrorize the population—to create panic and chaos,” Mr. Vilkul said. “We were lucky.”