An old degraded "castle and moat" volcano was discovered in Karaka after a man lodged plans to build a house in the location of the red circle. Photo / Supplied
An old degraded "castle and moat" volcano was discovered in Karaka after a man lodged plans to build a house in the location of the red circle. Photo / Supplied
An Aucklander's plan to build his dream house in rural south Auckland could go up in smoke following the discovery his land sits on the edge of a previously undiscovered volcano.
Wayne Valder, who owns the Karaka property, is planning on building a five-bedroom house with a basement and drivewayon the site - which currently sits vacant.
A land use resource consent application, which is now open to public submission on Auckland Council's website, was lodged in June and references plans for an open plan kitchen, living and dining area, an office, gym, sauna and a games room.
The Aucklander also wants to create a basement level where he could store his powerboats - which he competitively races.
Valder had been working up the plans for some time - he bought the property in 2014 with the intent of building a family home.
Late last year some Karaka locals contacted University of Auckland and Waikato University, asking for help to investigate locals rumours that a volcano existed in the area.
Auckland Council took the issue on and contracted a geologist and volcano expert to survey the site, who, using LiDAR scanning and onsite mapping discovered an old degraded "castle and moat" volcano.
Geologist Bruce Hayward said he was "absolutely staggered" by the find.
"All geologists knew there was no volcano near Karaka, which was outside the known limits of the Auckland and South Auckland volcanic fields," he said.
"How wrong we were."
Hayward described this type of volcano as rare - it was the first of its kind of be recognised for more than a century.
"There is an explosion crater with a tuff ring around the outside, and in the inside its got a scoria cone," he said.
"The cone in the middle is surrounded by a moat, so it's a castle with a moat around it and then a ring of ash around that."
Hayward said Valder's proposed earthworks and house sat on the outer crest of the volcano's tuff ring, with his suggested boundary for an Outstanding Natural Feature running through the proposed house site.
"My suggested boundary was to try to preserve the crest and view of crest of the tuff ring from damage and development," he said.
A council spokesperson said scheduling the site as an ONF would require a plan change to the Auckland Unitary Plan.
An old degraded "castle and moat" volcano was discovered in Karaka after a man lodged plans to build a house in the location of the red circle. Photo / Supplied
"Auckland Council has not yet received a Plan Change request, however staff in council's planning department are currently talking with stakeholders," they said.
Any submissions lodged before they closed on November 15 will be reviewed by a council planner and any issues raised would then be assessed.
Once the review is complete the planner will make an assessment of the application and submissions in a hearing report, which would recommend the next step.
According to Hayward, who had written a book investigating Auckland's landforms, it was fairly unusual for any type of volcano to be discovered in this day and age.
Most volcano forms in the Auckland region had been recognised and mapped in the 19th and early 20th centuries.
Hayward said there were 53 recognised volcanoes in the Auckland volcanic field, and a further 80 recognised volcanoes in the south Auckland field.
The rare nature of the Karaka volcano, along with the fact it was easy for the general public to recognise, prompted him to recommend the area for consideration as an outstanding natural feature.
