Winter weather caused substantial erosion along the Otago coastline this year and resulted in a landslip near an Aurora electricity station at Port Chalmers.
The loss of material has meant work has been required to stabilise the area.
A KiwiRail spokesman said the corner of a Port Otago building was damaged in the June slip but the surface of the track was not damaged.
''The Main South Line was closed ... for a short time and since then there has been no impact on rail services in that area.
''Work is currently under way to rock-anchor the top portion of the slip face ... [and] it will be made safe for work to begin on constructing a geogrid retaining wall.''
The total cost of repairing the slip is $1million and KiwiRail is working with the Dunedin City Council on a long-term drainage solution.
