One area needed 60m of new track and the track was moved about 8m sideways. In other areas, parts of the track were moved 2m sideways and realigned to get around areas where the earth had dropped out underneath.
Meantime the track will be monitored for the next eight months.
Duncan Neild, KiwiRail asset engineer, said that teams were able to get services up and running along the line just two weeks after the floods, allowing freight movements to continue as usual.
"Temporary speed restrictions have been applied along some areas of the line and are in place between Wanganui and Hawera. We're prioritising repairs in areas in preparation for our peak freight season, which starts on October 1," Mr Neild said.
That date coincides with the flush of the dairy season with the regular milk train service heading north to the Fonterra plant near Hawera, and dairy product from that factory making the journey south to link to the North Island Main Trunk and the country's major ports.
Justin Weir, KiwiRail's domestic and commercial vehicle freight national manager, said they had been working closely with their customers throughout the process to keep them informed of repairs and ensure that the impact on freight movements and scheduling was minimised.
KiwiRail has hauled an average of 1.2 million tonnes of freight annually over the past two years along the Stratford-Marton line - the equivalent of 91,000 truck trips if the same amount of freight had been carried by road.
Major commodities moved along the line include dairy products, meat, logs and gas. KiwiRail's peak freight season runs from October to April.
