An engineering report will also be obtained to reinstate the hole in the hillside measuring 150m by 25m and 20m deep. Council property manager Blaise Williams said the estimate of $1.6 million was a reasonable assessment for restoring the land to its original contours.
Negotiations will be with Ngati Whakahemo's Ngawhara Trust. Trustee Shane Swales said slips cause by the quarrying had exposed the bones of ancestors and the hill had been an historic battleground along an ancient coastal highway for Maori.
He said Ngati Whakahemo did not think the acquisition in the early 1940s was carried out correctly. It was hurtful to family and ancestors.
"We want the land returned."
Mr Swales said it was a big hole in the ground and the council had not shown a good example by leaving the quarry in an unsafe state. The trust represented over 100 owners.
Mr Williams said the quarry face was certainly dangerous. Negotiations would have to look at covering the council's stormwater requirements while trying to find a way forward.
One of the issues with reinstating the quarry was that it was dredged to about 8-10m below ground level - creating a man-made lagoon that was lower than the estuary.
He said the requirements of the Public Works Act stipulated that the council did not have to do more than return the land in its current condition.
Councillor Mike Pittar said if it had been a private quarry the consenting authority would never have allowed it to be left in that state.
"How it has been left in that state for so long, I will never know."
Cr Pittar said that while he had no problem in moving that the council enter negotiations, the trust should be aware that there was an extreme shortage of money and any process would be long term.