The Southland District Council will apply to the Provincial Growth Fund (PGF) to pay for the completion of an upgrade to the Observation Rock viewing platform.
A report from council community partnership leader Karen Purdue was presented to councillors early this week.
Ms Purdue said the platform had safety issues which needed addressed.
"Observation Rock is the most visited viewing platform on the island, largely due to its proximity to the township of Oban.
"It is now becoming a destination for night-time viewing with the island gaining accreditation as an international dark sky sanctuary."
The total cost of the project was $193,500, but the application to the PGF would be for $113,500.
She said the initial budget for the upgrade was $100,000, and the council received a grant of $80,000 from the Department of Conservation (Doc) through the Stewart Island visitor levy in 2018.
The extra $20,000 would be funded by "service in kind" from Doc and the council.
However, initial engineering plans showed the project required more work than anticipated and therefore the cost escalated.
Doc advised it was unable to find the extra funding required from its budgets and the Stewart Island Rakiura Community Board advised the visitor levy priority for funding was the rebuild of the Ulva Island and Golden Bay wharves.
Cr Karyn Owen asked what the other option would be if the council did not get the grant.
Ms Purdue said the platform would likely be closed due to the safety risks.
The council approved the request for unbudgeted expenditure of $193,500, subject to the PGF being approved.