A massive volcanic boulder has crashed onto an Auckland road where authorities had previously flagged a serious public safety risk from loose rocks.
The rock, which weighed an estimated 2 to 3 tonnes, fell from Mt Eden/Maungawhau’s lower slopes onto Clive Rd on Sunday morning, bringing down part of a retaining wall.
The Tūpuna Maunga Authority, an independent co-governance body that oversees the maunga, recommended “proactive structural work” in the area three years ago, with Auckland Transport (AT) now confirming at least three sections of an old stone wall were rebuilt.
Clive Rd was closed while the site was inspected for further hazards and the damaged retaining wall repaired. The road has since reopened.
A Clive Rd resident, who asked to remain anonymous, told the Herald it was the third rockfall he had seen at the site this year, with smaller rocks coming down in January and April.
“It’s not really a shock, it’s been ongoing,” he said.
“There are massive basalt rocks falling down that side of that road and there are kids that walk up that road on a daily basis.
“It’s only a matter of time until someone gets killed.”
The fall followed a wet end to the week, with about 25mm of rain recorded in Auckland on Friday and Saturday.
Images show the gigantic boulder resting across a footpath and jutting onto the road, surrounded by chunks of stone and debris.
The resident said he drove along Clive Rd about 10 minutes after the April rockfall.
“If I’d been 10 minutes earlier, it would have landed on the car, so it would have killed me or my family.”
AT confirmed it was aware of earlier rockfalls at the location involving smaller stones.
“Volcanic stone fields such as this location are prone to shedding material from time to time,” a spokesman said.
The resident’s concerns echo a public safety warning recorded by the Tūpuna Maunga Authority three years ago.
The authority’s 2023 Health and Safety Register recorded a complaint about a “large boulder which had come loose and was suspended over the road reserve on Clive Rd”.
The register identified the area in question as being within the road reserve and therefore AT’s responsibility and recorded a risk to vehicles and members of the public.
“Long term have requested that proactive structural work is undertaken on this area,” the register said.
An AT spokesman said this morning that the “2023 event related to a single rock that fell from this stone field but was restrained by a tree and so did not reach the road”.
“AT removed the rock and the damaged tree under a road closure at night.”
AT initially told the Herald no further work had been done beyond removing the loose rock, clearing vegetation and inspecting the site.
After publication, AT said it had spoken to its engineers and established that as a result of the inspection of the stone field above the road to check for any other stones or vegetation that could come down on Clive Rd, an older dry-stack stone wall built to contain livestock had been identified.
“This wall was in a poor state of repair with several of its stones loose or displaced and at risk of migrating further down the bank towards the road. We rebuilt at least three distinct sections of this wall and removed from site any of the loose stones not used in its rebuild.”
AT initially said the area sat within a Heritage New Zealand overlay, which restricted what it could do without specific consent or oversight.
It also said Heritage NZ was “keen for the maunga and lower slopes to remain in its natural state with as little modification as possible”.
AT said it had since carried out localised rock removal and vegetation work, but had not undertaken “wholesale removal of rock and other material of the maunga”.
Heritage New Zealand Pouhere Taonga told the Herald it had not been involved with AT regarding any work around Clive Rd.
“The heritage overlay sits with Auckland Council and not Heritage New Zealand Pouhere Taonga,” a spokesperson said.
Auckland Council acting heritage manager Anna Boyer told the Herald Maungawhau/Mt Eden was scheduled as a Category A* historic heritage place in the Auckland Unitary Plan (AUP).
However, she said the area from which the boulder was dislodged was outside the scheduled historic heritage area.
Boyer said resource consent may be required under the AUP for matters relating to historic heritage if future mitigation works extended into this area.
“However, the Resource Management Act allows for authorised persons to carry out urgent activities without prior resource consent to prevent or remediate sudden threats to life, property or the environment,” she said.