Power was cut to hundreds of homes in Lincolnshire when more than a mile of overhead cabling was stolen.
The theft took place in the Burton Fen area on Tuesday evening and affected homes in Burton Waters near Lincoln.
Police said the theft was highly organised and offenders used a dinghy to cross a stretch of water to steal the 1,968 yards (1.8km) of cable.
At the weekend another village was blacked out after 1,090 yards (1km) of cables were stolen at Newton on Trent.
In August there was also a significant overhead power line theft in Lincolnshire after cabling was stolen in Normanby-Le-Wold.
A Lincolnshire Police spokesperson said they were looking into possible links between the thefts.
A £5,000 reward is being offered by the power distribution company Western Power for information leading to a conviction.