However, the trust that runs the Dunedin Gasworks Museum says it is hopeful it can retain as much of the 118-year-old chimney at the museum as possible — it is the oldest structure on site.
Visible cracks in the chimney have been present for at least a decade, but last month’s 6.8-magnitude earthquake caused new cracks and aggravated the existing ones, the Dunedin City Council said.
Neighbouring Dunedin South Woolworths was told to manage the risks that a potential collapse could have, and public access to the museum was prohibited.
Dunedin Gasworks Museum Trust chairman Jonathan Cweorth said yesterday the council told him it was looking at a range of options for the compromised chimney, and no decision had been made yet.
The options were either demolishing, repairing or shortening the chimney, Mr Cweorth said.
He said he had not been told how much it would cost to retain it and was waiting on reports from the council’s engineers, due by the middle of next week.
Mr Cweorth said he was at present feeling better about the fate of the chimney than he did when he first learned about the issue.
The council had acted "pretty fast and efficiently" to try to keep the museum’s operations from being unduly disrupted.
The site might be at least partially usable from some time next week, he said.
"It looks like we can cordon off the dangerous part and make an exclusion zone on the site to keep everyone safe, but still use the front parts of the site as we would normally."
A Dunedin bricklayer, with more than 20 years’ experience and who the Otago Daily Times has agreed not to name, doubted the chimney would remain standing.
"My best guess would be that it needs rebuilt, and I highly doubt they’re going to do that, because that would be a real expensive job," he said.
"Then you’re looking at dealing with the same problem in a few years’ time when we get earthquakes."
He said while metal brackets had been installed to secure the structure, multiple earthquakes over the years had caused the damage.
Any modern brickwork was purely for cosmetic use because of that earthquake risk.
"It’s one of those tricky things where they like to preserve all our history and that, but sometimes it’s just not going to pan out," he said.
This week, the council said a drone inspection found cracks in the brickwork of the historic 25m chimney after a member of the public noticed its lightning rod had come loose.
On Thursday, property services group manager Anna Nilsen said issues extended beyond a pre-existing large crack, which had been visible since at least 2015.
"Comparing drone footage taken in 2024 to the most recent footage, we can see evidence of new cracks and movement within the structure, as well as a further deterioration of the large crack.
"Based on the expert advice we’ve now received, we’re taking precautionary steps to ensure public safety while these issues are addressed."
While cracks in the upper part of the chimney were a concern, an engineer’s report found the lower sections had not significantly changed recently.
"Should the chimney fall, it would likely be limited to its upper section, reducing the size of the area around the chimney that would be affected," Ms Nilsen said.
"Based on this, our building services staff are confident surrounding businesses can remain open with only limited temporary arrangements in place."
The council issued a dangerous building notice to the gasworks site on Thursday, prohibiting public access until the chimney’s issues were resolved.
It was expected to remain closed over the weekend, but the facility might reopen with restricted access next week, Ms Nilsen said.
"The gasworks site is an incredibly important and well-used community gathering space for a wide range of groups, and we’re working hard to allow them to continue to provide this valuable service as soon as possible."
The site is a category 1 historic place owned by the council and operated by the trust.
A Woolworths spokesman said the council requested the business protect a specified area of its roof.
"We’re responding to this as quickly as possible, and expect this work to be completed [today] at the latest.
"In the meantime we have restricted access to the affected corner of our store."
— Additional reporting Laine Priestley
