The trust that runs the museum says it is not clear whether cracks in the structure have been exacerbated by the recent 6.8 earthquake off the southern Southland coast.
The Dunedin City Council yesterday said the museum would close for at least a week while the safety of the site’s chimney stack was assessed after a member of the public noticed a lightning rod running up the chimney was not flush with the brickwork.
A statement from DCC group manager property services Anna Nilsen talked of "changes" to the chimney’s structure being discovered last week.
She said staff "suspect the cracks may have been caused by last month’s large 6.8 magnitude earthquake".
Trust chairman Jonathan Cweorth said the concern was that "existing cracks have been exacerbated by the recent earthquake".
It was the first time extensive drone footage had been used to look at the cracks.
The works operated from 1863 to 1987 and the site and facilities are identified by Heritage New Zealand Pouhere Taonga as a Category 1 historic place.
The council said the chimney was regularly inspected.
Ms Nilsen said the council, as landlord, had chosen to close the site as a precautionary measure while further investigations were carried out.
The situation also had the potential to impact surrounding businesses, and the council was working proactively to keep everyone informed.
The closure is effective immediately and the council has asked for an engineer’s report on the structure, which is expected to be ready shortly.
A Woolworths spokeswoman said it was informed of the situation yesterday, and noted the council was awaiting an engineer’s report.
"We will stay in contact with the council and assess next steps once the report is available."
The safety of the chimney has long been an issue the council has been aware needs addressing.
In a 2013 council discussion about funding needed to upgrade buildings on the site, including the chimney, then council property manager Robert Clark told councillors the chimney was probably in better condition than other buildings, but "does raise issues from an earthquake point of view".
The council was then awaiting an engineer’s report on the chimney’s condition, but Mr Clark expected it would be more of a priority than other buildings.
"It’s a high brick building ... If we were to have a shock, there could be issues there."
Trustee Ann Barsby said yesterday the 2013 report from engineer Lou Robinson found that the chimney was "perfectly safe".
"So there's no threat to anyone on the site. But some of the pointing was going to need some attention."
