Okuru Enterprises wants to pipe water from Tuning Fork Creek, which flows from the west side of Mt Aspiring National Park, to a bulk water storage facility at Neills Beach, south of Haast.
It would then be piped to tankers anchored off Jackson Bay and exported.
Botanist and University of Otago Emeritus Professor Sir Alan Mark has joined a chorus of voices against the project.
He said he wrote in March to the Minister for Conservation, the Green Party MP Eugenie Sage and the West Coast Regional Council, which granted the permit to build the pipeline at Neills Beach, to express his opposition to the Okuru Enterprises proposal, which would have the pipeline constructed through the Haast tokoeka kiwi sanctuary.
He knew the area well, he wrote, and as patron of the Pomona Island Conservation Trust, where there was a creche for the kiwi, he was also involved in its conservation.
The Haast Tokoeka Sanctuary had been recognised by the Department of Conservation (Doc) to ensure the survival of the endangered species and the intrusion of a pipeline, as proposed, through the sanctuary is "totally at variance with the conservation needs of this and other indigenous species", he said.
Sir Alan told the Otago Daily Times he believed his March letter and comments were "totally ignored" by the council as it granted the permits earlier this month.
Sir Alan (85) said he had spent much of his life doing ecological studies in the Mt Aspiring National Park and South Westland.
In the summers of 1968-69 and 1969-70 he conducted a comprehensive vegetation survey of Mt Aspiring Park for what was then Otago National Parks and in the 1970s, together with two other ecologists, he carried out a land-use study of South Westland for the former Lands and Survey Department and the New Zealand Forestry Service.
Each ecologist was asked to nominate the most ecologically significant area and Sir Alan nominated the "Burmeister" which was then proposed by the Scientific Co-ordinating Committee to the Forestry Service to become an extension of the Mt Aspiring National Park.
"It was never formally gazetted, as the Forestry Service went into receivership in 1987 and all their lands came under the control of the Department of Conservation who never got around the formalising it as a reserve," he said.
It would have created a protected corridor of vegetation from the crest of the Haast Range to the sea, preventing developments like the one proposed by Okuru Enterprises.
In 1994 the Department of Conservation granted the company an easement across what had become the Arawhata Conservation area to construct and maintain a weir and pipeline and to convey water.
Sir Alan said that was an "indictment on Doc" as it had since recognised the importance of the Haast kiwi in the area by creating the kiwi sanctuary.
Doc Western South Island operations director Mark Davies said at the time the easement was granted in 1994, little was known about the Haast tokoeka.
Since then, Doc had established the kiwi sanctuary, in 2000, so while the land had not been reclassified, there was recognition a nationally significant species lived in the area and needed to be managed appropriately.
West Coast Tai Poutini Conservation Board chairman Michael Legge said the board also had ongoing concerns with the Okuru development, which it had discussed with Doc.
Mr Davies said now Okuru Enterprises had this consent it could start the project, but resource consents and a renewed deed of easement, which expires in 2019, were also required. For those a significant amount of detailed plans and management options would need to be developed, all before any construction could begin.
The company had not signalled any immediate plans to develop anything, and it had been told if it reapplied for an easement in 2019 any application would be publicly notified. Sir Alan said he would "stand in front of the bulldozer" if he had to.
