They will now be restored thanks to an agreement between the Department of Conservation (DOC), the Southland District Council and the Port Craig Viaduct Trust.
Conservation Minister Dr Nick Smith made the announcement yesterday.
"We need to restore and protect these massive viaducts as a tribute to the incredible engineering feats of our pioneering ancestors," Dr Smith said.
"They are a spectacular feature of the Hump Ridge Track along the south coast of Fiordland that generations of New Zealanders and international visitors must continue to be able to enjoy."
The cost of restoring the viaducts has been put at $480,000. DOC will provide a $160,000 boost towards the work over the next financial year.
Funding problems were difficult to resolve because no one organisation had responsibility and parties could argue for years over who should be funding what, Dr Smith said.
"I admire the typical southern pragmatism that has delivered this long-term funding partnership where costs will be shared one third each between the Government, the council and community.
"This agreement is particularly good for the Tuatapere Hump Track Charitable Trust and Southland tourism, as the option of rerouting the track around the viaducts would take away some of the 'wow' factor of the Hump Ridge Track experience."