Anthony Zambonini, 59, suffered flash burns to his arms and face, and David Leven, 33, was blown off his feet and had an eye burned when the incident happened at a site in East Kilbride in July 2009.
Mr Zambonini thought he had struck rock and used a steel bar to break up the ground, unaware he was hitting an 11,000 volt live electrical cable.
The Hamilton man needed treatment in a specialist burns unit and was off work for four months. Mr Leven, from East Kilbride, made a full recovery.
The incident was investigated by the Health and Safety Executive and South Lanarkshire Council was fined £35,000 after admitting breaching the Health and Safety at Work Act.
HSE Inspector Mark Carroll said: "South Lanarkshire Council understood the risks of striking underground services and still failed to implement its own recommended system."