Orion is to build further overhead temporary power cables in the eastern suburbs of Christchurch to meet higher power demands over winter.
Chief executive Roger Sutton says the damage to four large underground cables is such that a new substation will need to be built in Keyes Road, New Brighton, to replace one which has sunk in Pages Road.
Mr Sutton says Civil Defence has approved building the substation and 1.5km of cable to run from the existing New Brighton substation to the new one.
A further 1.5km of overhead cable will run between substations in the suburbs of Bromley and Dallington.
Mr Sutton says the work is expected to begin in early April and be operational in mid-May.
He says the approval for the overhead cables is for three years, but Orion will begin rebuilding underground cables as soon as it can.