A Southland rail line is set to be mothballed - with KiwiRail ruling it's not worth investment, given the closure of the coal mine it services

Bathurst Coal's shutting the Takitimu Mine next year because coal supply is exhausted and further expansion isn't viable, due to decarbonisation strategies.

KiwiRail says it means there'll be no freight to transport on the 79 kilometre line between Invercargill and Ohai, which suffered severe damage in severe weather in 2023.

Chief Infrastructure Officer Siva Sivapakkiam says Kiwirail can't justify the million dollars of repair work to initially open the line, let alone the tens of millions needed for upgrades over five years.