Conservation Minister Eugenie Sage is considering a court challenge to a proposed peat mining venture in the Far North.
The Northland Regional Council has approved plans by an Auckland company to dig up 400ha of Māori-owned land in the Kaimaumau swamp, north of Kaitaia.
The project has the support of the iwi Ngāi Takoto and the blessing of the council's economic development arm.
But the Minister Eugenie Sage said it was a project that belonged in the 1900s.
The council granted resource consents this week for Resin and Wax Holdings to go ahead and dig, although it still needs a mining permit to do so.
The company has found a way to extract valuable industrial compounds from the ancient peat soils of Kaimaumau.
The council processed the consents in house and did not publicly notify the applications.
Staff accepted reports commissioned by the company which concluded that the deep digging would not damage DOC's neighbouring protected wetlands, including a scientific reserve, or the underlying aquifer that supports them.
Eugenie Sage said she was extremely disappointed that the council never tested those assurances by notifying the consents.
"It's always good in RMA decisions to have information from a range of sources, not just the applicant," she said.
"Views will often differ on biodiversity values, and sources may differ on the environmental impact and the hydrology."
Heritage New Zealand was also taken aback by the council's actions.
HNZ's Northland manager Bill Edwards said councils were required by law to notify Heritage NZ about any plans to dig up archaeological sites.
But in this case the Regional Council had failed to do so, he said.
There were numerous sites of interest in Kaimaumau including an old radar station, the remains of gumdigger camps, middens and early Māori sites, Mr Edwards said.
"The council has ticked the box in the consent form for potential effects on archaeological and historic sites but it hasn't followed through by notifying us as the affected party," he said.
Mr Edwards said the resource consents should not have been granted in the absence of an archaeological assessment and plan.
"It shouldn't have happened. There's a clear process and that either hasn't been followed or has not been done as a result of a mistake," he said.
The Regional Council has not yet responded to an invitation to comment.
Eugenie Sage said DOC advised the council of its concerns that peat-mining would endanger threatened wetland birds and plants, including rare orchids.
"You know, when we have lost 90 percent of our wetlands, having peat mining in a wetland next to a nationally significant wetland system and as part of a whole mosaic of wetlands and dune lakes, that's behaviour that belongs in last century," she said.
Ms Sage said she was now seeking advice from Crown Law on whether DOC could challenge the Northland Regional Council's resource consent process by taking it to judicial review.
Over several years, Resin and Wax has had more than $300,000 in government grants through the Callaghan Innovation fund.
It expects to employ up to 30 Ngāi Takoto people, and has promised to hand over to the iwi any swamp kauri logs it unearths.
The project has had the backing, but no financial support, from the Regional Council's economic development agency, Northland Inc.