A plan to extract valuable waxes and resins peat wetland at Kaimaumau, that Ngai Takoto hopes will help secure its economic future, may be blocked by the government.
Heritage NZ also has concerns about the Northland Regional Council consent granted to Auckland firm Resin & Wax Holdings to work about 10 per cent of the more than 4000ha wetland, given the presence of historic sites ranging from an old radar station to the remains of gumdigger camps and middens.
Conservation Minister Eugenie Sage is now seeking legal advice before possibly appealing the consent.
The peat mining area was adjacent to conservation land, the Kaimaumau-Motutangi wetland complex, which was nationally significant because of its size and the mosaic of wetland and dune ridges, she said, supporting rare and threatened plants, reptiles and birds. It was also one of the few wetland areas left in New Zealand.
"Ongoing wetland loss is a significant concern to me, given that only 10 per cent of New Zealand's wetlands remain," Ms Sage added.
"Peat mining risks significant adverse effects on conservation values and wetland functioning in and beyond the application area. These include the fragmentation or loss of habitats for threatened species, such as some rare orchids.
"It is disappointing that the council chose not to notify the application to allow public submissions, or consider DoC as neighbouring landholder as an affected party," she added.
"It's always good in Resource Management Act decisions to have information from a range of sources, as views will often differ on biodiversity values, and sources may differ on the environmental impact and the hydrology."
She had been advised that DoC was reviewing the consent conditions to determine if they would adequately manage the effects of mining.
Te Runanga o Ngai Takoto CEO Rangitane Marsden, who has described the venture as a big win that would help secure the iwi's economic and environmental future by providing jobs and opportunities for its people, said the area to be mined was essentially a "wattle farm" with toxic soil.
"We knew the farm required a lot of work to bring it back into any kind of state that it could be used to provide any economic benefit, but the environment is a big part of our kaupapa, and that had to be a primary focus," he said.