In a thickly forested park bordered by apartment blocks and a playground, a dozen workers were busy on a recent day with chain saws and axes, felling trees, cutting logs and chopping them into firewood to be stashed in concealed sheds around Lviv, the largest city in western Ukraine.
Ironworkers at a nearby forge are working overtime to produce wood-burning stoves to be stored in strategic locations. In municipal depots, room is being made to stockpile reserves of coal.
The activity in Lviv is being played out in towns and cities across Ukraine, part of a nationwide effort to amass emergency arsenals of backup fuel and critical provisions as Russia tightens its chokehold on energy supplies across Europe.
As President Vladimir V. Putin slashes natural gas flows to Ukraine’s European allies, the government in Kyiv has accused Russia of also stepping up the destruction of critical infrastructure that provides heat, water and electricity to millions of homes, businesses and factories.
“All cities are preparing for a hard winter,” said Andriy Sadovyi, the mayor of Lviv, where Russian rockets knocked out three electrical substations in April, temporarily cutting power to neighborhoods. “Russia has turned off the gas to our neighbors, and they are trying to pressure us, too,” he said. “Our goal is survival. We need to be ready.”