The proposed mine site at Mt Te Kuha, near Westport. Photo: Neil Silverwood via RNZ

Forest & Bird has won an appeal against the development of an opencast coal mine on the West Coast of the South Island.

The Court of Appeal released a decision yesterday which means the Buller District Council needs to protect the special features of the Westport Water Conservation Reserve, which had been slated for use in the controversial Te Kuha opencast coal mine proposal.

Mining company Stevenson Mining had argued that protection of the natural and biological features was only one matter the council had to consider and that it could weigh this against the economic benefits of the mine.

But the court found the council could not allow access to its land that was incompatible with the primary purpose of the reserve and had a duty to protect its natural and biological features.  

Forest & Bird's lawyer Peter Anderson said the council was bound by the Reserves Act and needed to protect the environment. He said this sets a precedent for future coal mines on reserve land.

"The natural and biological features of this reserve have to be protected, and that's fabulous news for the plants and animals up there because it's a unique ecosystem and so protecting those values is kind of inconsistent at first glance with an opencast coal mine," Mr Anderson said.

It is the latest blow for Stevenson which has been developing its plan for the Te Kuha mine for years.

In June this year the Government turned down its application to mine on the conservation land.

The company has said it intends to apply for a judicial review of this decision.

Stevenson Mining's chief executive Mark Franklin said it was too early to say what the latest court decision meant for the mine and it would be discussed by the board early next month.