The Taieri Gorge railway line is set to reopen next month after an expensive flood damage clean-up.
Parts of the track, particularly between Hindon and Parera, were blocked by slips caused by severe flooding on July 22-23.
Dunedin Railways engineering manager Ward Kellett said it was hoped the line would reopen on September 16.
He could not confirm how much the clean-up would cost, but said it would be "a scary number".
The exact total was dependent on findings by geotechnical experts.
Geotechnicians were investigating what needed to be done to secure a section of track about 13km from Wingatui in the long term.
"This is a traditionally slower-moving area that did move a little more with this rain," Mr Kellett said.
A drone was first used to document the scale of the damage and a train and truck had been used at opposite ends of the track to carry out repairs.
About 10 staff, including contractors, had worked seven day weeks to clear the track as quickly as possible.
Mr Kellett praised the work of contractors.
"Without them we would certainly be dead in the water still."
The debris was mainly from surrounding forest and there were "tonnes of cubic metres" of mud from surrounding hills.
Dunedin Railways had worked with KiwiRail to operate seaside services to Palmerston and a 7km
Taieri Gorge trip run this week.
