As an overhaul of earthquake-prone building legislation starts, there’s division in Dunedin and Coastal Otago, the only part of the country, being escalated from a low to medium risk zone.
A heritage trust is concerned historic buildings will be demolished, but scientists stress the earthquake risk to Dunedin in particular is much more than previously thought.
That’s because part of the Akatore fault is just fifteen kilometres south of the city, although it has been ‘quiet’ in our lifetimes.
University of Otago’s Professor Mark Stirling said the latest geological findings suggest: “The main shock would be a lot like the main shock of the Canterbury earthquakes.”
“And it [the fault] also goes south almost to the mouth of the Clutha. So it’s a big earthquake source. It’s a magnitude – we estimate – magnitude 7.5.”
But as Dunedin’s land risk level is raised under the proposed earthquake-prone building system overhaul, the Southern Heritage Trust is concerned insurance premiums will go up, property values will go down, and that owners will choose not to retrofit quake-prone buildings – rebuilding instead.
Spokesperson Jo Galer said: “People just can’t, there’s projects that are falling over where people want to do good things with their heritage buildings and reuse them. But they can’t do that because the costs just don’t stack up.”
She said: “Dunedin has one of the highest collections of heritage in Australasia in one place.”
Dunedin Mayor Jules Radich said: “We certainly don’t want to lose any [old buildings] if we can avoid it.”
“At this stage, there’s a lot of uncertainty.”
The Ministry of Business, Innovation and Employment told 1News that if the changes to legislation are passed, the Dunedin City Council has until 2032 to finish assessments, and once assessed, building owners still have 25 to 35 years to fix them.
Earthquake risk advisor Dave Brunsdon said: “This part of our building regulatory system is complex. It involves a number of key roles by council officials, engineers, owners and the amount of work involved in the process cannot be underestimated under any system.”
If the proposed law changes are passed, the new system would likely come in later next year.