OceanaGold is proposing a new underground mine in Waihi - and part of the proposed mining area is under residential properties.

The mining company has identified more gold under the Martha open pit.

Before it can start mining in 2020, OceanaGold will need several resource consents approved.

Part of this proposed mining area is located under residential properties, between Mueller and Gilmour Sts.

Advertisement

OceanaGold's Waihi general manager Bernie O'Leary said the small ore body under residential properties could be mined within two years, but the whole project could extend the life of the mine by more than 10 years.

"Within the open pit we plan to complete remediation of the north wall, which will give us access to the ore at the bottom of the pit, and then use this material to backfill the stopes we plan to mine, and some of the old stopes from pre-1952 mining activities," he said.

Work at the Martha pit has been limited since the slips on the north wall, with the first in April 2015.

However, former Green MP Catherine Delahunty said she was concerned about the stability of the pit if it were to be mined again.

"I am not surprised by this announcement because way back in the past, the extension of Martha open pit has always been the plan. At the time, they wanted to shift the town to mine this area. It is clear that they are extending and they are mining the heart out of Waihi," she said.

OceanaGold had been working towards reopening the pit, knowing 75,000 ounces of gold worth about $75 million had been left behind after the first slip.

"As far as I am aware, mining companies in Waihi have never had a resource consent rejected . . . This is a hard road to object anything, even for residents," Delahunty said.

At this morning's presentation, OceanaGold Waihi General Manager Bernie O'Leary said the proposed project would see mining continue in the town for an estimated 11 years.

Hauraki District Council mayor John Tregidga said OceanaGold outlined its plan to the council today.

He said the proposal by OceanaGold was not yet final and there was a resource consent process to be followed.

The company has started consulting with the community and has indicated it will lodge a number of consent applications in about two months.

"Once we receive an application from the company the consent process will allow community feedback in a variety of ways including face to face conversations, online comments, and formal written submissions," he said,

"The council will ensure all information is available to the community as soon as possible."

He said the council would use independent professionals to ensure the information received from the company was technically robust, and independent commissioners would be engaged to listen to community feedback and make a decision.

"The council needs to consider the interests of all the people in Waihi; this includes all residents, ratepayers and all businesses."

Mayor Tregidga said since purchasing the Waihi Gold Mine from Newmont Mining Corporation in October 2015, OceanaGold had been actively engaged in exploration work.

"We're aware the company is continuing to explore and study other mining opportunities this year and beyond, and we expect we'll see other mining proposals come through these doors in the future."

O'Leary said the Hauraki District Council's 2017 economic profile showed mining was a significant contributor to the district.

"Project Martha would continue to support this contribution, delivering a similar production rate to current operations, with a peak of around 420 jobs, and an average of 350 fulltime jobs each year over the 10-year period.

"And it means we can continue to partner in a meaningful way with our community, including our schools, over the next 10 years."

OceanaGold will hold a community open day on April 4 between 2pm and 7.30pm at Waihi's Baptist Church.

"We know from our interaction with Waihi East residents during the announcement phase of our Correnso underground mine that people don't like surprises and don't like uncertainty, and they certainly don't like the idea their home could be affected or be worthless as a result of our proposal.

"There will be an open day for the wider community, and we have also produced a series of information sheets that people can collect at these meetings, from our office, or download from our website."

Public open day
- April 4 from 2 to 7.30pm at Waihi's Baptist Church
- More Information is also available on the OceanaGold website