The court heard that an alarm, specifically designed to prevent this happening, had been disabled.
The jib of the truck loader crane hit a live 20,000 volt overhead power line at one of the council depots.
The incident, on 19 February 2010, happened after the wagon was unloaded and the crane jib was left in the raised position. The overhead line was brought down to the ground. Despite the dangers, no one was hurt.
Bedlington Magistrates' Court heard the investigation by the Health and Safety Executive (HSE) found that the alarm had been disabled. HSE told the court the driver had never used the Stakeford Depot, in East View, Choppington, before and as there were only small warning signs for the overhead power line, he was not aware the line spanned that section of the site.
Inspectors found that, apart from two small warning signs, there were no safety precautions in the area around the overhead line. HSE guidance suggests avoiding working near overhead power lines whenever possible, but if not avoidable then measures such as goalposts, clear zones beneath the line, designated vehicle sites and large warning signs should be used.
HSE inspector Sally Brecken said after the hearing: "Direct contact with electrical equipment at such high voltages is very likely to lead to fatal injuries through either electric shock or burns. This was a narrow escape that could have easily been avoided.
"If the alarm on the crane had been functioning the driver would have been aware the crane was still raised before driving off and if suitable control measures around the overhead power line had been in place, the driver would have known about it.
"The first consideration should always to be to avoid working near overhead power lines and in this instance it was possible for them to be relocated, which has since been done as Northumberland County Council has re-routed the power line underground around the perimeter of the depot."
Northumberland County Council pleaded guilty of one breach of Regulation 4(3) of the Electricity at Work Regulations 1989 and was fined £13,400. It was also ordered to pay £8,364.50 costs.