The UK's Defense Ministry said flooding disrupted the peninsula’s main source of fresh water, the North Crimean Canal.
Many have been left without adequate drinking water, while many animals have been killed and people have been forced to evacuate from their homes.
"The enemy's goal was to break through our defenses in the most vulnerable, in its opinion, sector of the front," the defense ministry said.
The defense ministry's intelligence directorate said Russian forces would soon shell the plant and then announce a radiation leak.
"All emergency services are working at the scene. The cause of the incident is being investigated. Residents are asked to stay calm," Krasnodar mayor Yevgeny Naumov wrote on Telegram.