Minister of Conservation Dr Nick Smith will decide if proposals for the Milford Dart Tunnel and a monorail go ahead.

The decisions were to have been made by the Department of Conservation.

Smith said he had decided, given the scale of the projects and the huge public interest in them, it was not appropriate for the decision to be delegated to a Conservation Department official.

"These are public lands and it is proper that these decisions are made by a publicly elected and accountable official," he said.

The decisions would be difficult and he had taken advice on ensuring a robust process, he said.

"Parks and reserves are much loved areas of New Zealand set aside for conservation and recreation. There is a particularly high threshold for projects in our national parks. However, New Zealand also needs jobs and economic development."

Smith said he would be advised by the Department of Conservation and expected to receive the department's reports on the Milford Dart Tunnel soon and the Fiordland Link Experience in a few months.

The Fiordland Link Experience proposes a private 43km monorail to shorten the route from Queenstown to Lake Te Anau.

The proposed route would largely run through the Snowdon Forest, part of which falls into the Southwest World Heritage site, which is home to several critically endangered birds, lizards, plants and the short- tailed bat. Of the 43km monorail trip, 29.5km would be through DOC land.

The Milford Dart Tunnel proposal is for an 11km tunnel through the Alps from Glenorchy to the Hollyford Valley allowing tourists to visit Milford Sound in a much-shortened two hours.

Southland District Mayor Frana Cardno said she hoped the minister did his homework thoroughly before coming to a decision.

"We hope that he looks at our environmental heritage and takes on board the law.

"With world heritage comes obligations to understand the natural values," she said.

Save Fiordland chairwoman Daphne Taylor said she was glad the decision would be made by the minister, because it showed the importance of the decision.

"We hope that it reflects his understanding of how significant that world heritage status is on every level," Taylor said.

The group wanted the minister to have a full understanding of the law and conservation management documents before making a decision.

Federated Mountain Clubs president Robin McNeill said that he was confident the minister would review the evidence objectively and impartially, and realise the process to date had been flawed.