Waitaha wants a heritage order over an escarpment in the Waiareka Valley, which could have a major impact on the proposed Holcim (New Zealand) Ltd US$400m cement plant development.

The Maori tribe has asked Minister of Maori Affairs Pita Sharples to exercise his powers under the Resource Management Act (RMA) to protect Te Ana a Raki, also known as the Whitston escarpment, which Holcim wants to mine for limestone and tuff.

If Dr Sharples issues a heritage order to the Waitaki District Council to designate the escarpment in its district plan, it could prevent mining.

Waitaha sent a letter to Dr Sharples last week, after the Environment Court rejected an appeal against the cement plant and found the escarpment was not of outstanding natural, cultural or spiritual value.

Dr Sharples office could not comment on Friday.

Holcim capital projects manager Ken Cowie said on Friday his company was aware of the Waitaha request only through what it had read in the Otago Daily Times last week. Mr Cowie said that, at this stage, Holcim was still studying the court’s decision and conditions and going through the process needed for its parent company in Switzerland to make a final decision – later next year, at the earliest – as to whether or not to build the plant.

Holcim also planned to contact and consult with the groups involved in the appeal to the Environment Court. One of those groups was the Waitaha Taiwhenua O Waitaki Trust Board, which appeared as an interested party.