"It's only part of our farm that has sold - only 36ha and we have 81ha left," Colin Devine said this week.
"I have five daughters, 14 grandchildren and a great-grandchild and we intend to keep the rest of the land forever."
The sale and consent process took 16 years, covering objections from locals and an Environment Court hearing.
Devine said the process with council started in 2002.
Consent was given by the Environment Court in 2013 and a sale to Wawata Estate was finalised this month.
Property records show Wawata Estate's director is Christopher James Jacobs.
Jacobs was the executive director of Marine Holdings Ltd, which owned Fullers Bay of Islands.
That company sold in 2004 for $22m.
Wawata Estate project manager Greg Robbins said it would be a low-density rural development.
"With the house sites occupying just 15 per cent of the total land area, the finished estate will resemble a 94 acre park dotted with discreet, thoughtfully placed homes," he said.
He said there would be improvement to the land, now covered in gorse and tobacco weed.
Wawata Estate had worked with local iwi and Heritage New Zealand and archaeological sites had been identified and would be protected.
The consent had 130 conditions attached that protected existing neighbours' views, public walkways, many large native trees and wetlands.
"The new owners are only too happy to comply with every one these conditions and, in fact, will go further," Robbins said.
He said the development would be of high quality and have improved public walking tracks and new access to Sea View Rd.
But some locals are still upset the chunk of rural land had been rezoned.
Local resident Rosie Walford wrote to Auckland Council asking for the rezoning to be publicly notified but "hadn't heard back".
She said there was great sadness in the community that the rolling hills and bird corridor were going to "become part of suburbia" with private roads and houses.
"It is a very special place with incredible birdlife and it is worrying that this rezoning can happen without notification," she said.
"There is something very awry when land can be rezoned like this."
Matthew Smith of Ray White said the block of land was the last of its kind for sale and that the final development would be an asset to the island.
"It is going to be really nicely done with beautiful homes, roads and lighting," Smith said.
"They will be architectural designs that will be a real asset."
The sale is the second multi-million dollar transaction in the past six months on the island.
Last week the Weekend Herald reported a $20m mansion in Church Bay had sold to a foreign buyer -with the sale subject to approval from the Overseas Investment Office.
Planning for Wawata Estate will continue throughout winter with clearing, re-vegetation and civil works starting in October.