A New South Wales-based company has put forward a new plan to dam Western Australia's Fitzroy River.
AM has obtained a leaked copy of the detailed proposal from retired NSW cotton farmer and KIMCO founder John Logan.
The document argues it could transform the Kimberley into a cotton powerhouse rivalling New South Wales and Queensland.
But environmentalists, like Martin Pritchard from local environmental group Environs Kimberley, warned it would destroy the river, which they want protected by law.
"The Fitzroy River would never be the same again, it would turn into a ditch essentially to carry water for irrigation," he said.
KIMCO's plan is to construct a dam near Dimond Gorge, on the upper reaches of the Fitzroy and another on the nearby Margaret River.
Mr Logan has been keen to set up a cotton industry in the Kimberley for decades.
He has put a $6 billion price tag on this proposal, which would see Fitzroy water irrigating 300,000 hectares of grain, cotton and horticulture.
The document suggests the project would involve a new port in the Kimberley and see the creation of "a new coastal community township".
KIMCO said it would also require "the consolidation of a number of cattle grazing stations".
Damming the Fitzroy not backed by politicians
WA's Labor Government went to this year's election promising it would never allow the Fitzroy to be dammed and there was no appetite for KIMCO's plan from WA's Agriculture Minister Alannah MacTiernan.
Environmentalists want legislation to protect the Fitzroy River from any future proposals.
"There is absolutely no doubt that there is a massive capacity to expand horticulture and agriculture in the West Kimberley and we're very committed to doing it," she said.
"But we don't believe that it should be predicated on damming the Fitzroy River, and certainly that's not the advice that has come out from over a number of years from the CSIRO."
Before he quit his role as Northern Australia Minister on Tuesday, Matt Canavan was not backing it either.
"There has been significant opposition from Indigenous and traditional owner groups in the past, although there are a mix of views is my understanding and that's obviously a relevant consideration," he said.
"We're not seeking to impose dams on the rest of the country, we're seeking to build dams where there is a welcome mat for dams if you like, and there are plenty of places where there is a welcome mat for dams, including in Central Queensland and North Queensland."
Through its Northern Australia Infrastructure Facility, the federal Government is offering up to $5 billion in concessional finance to encourage infrastructure in northern Australia.
It is unclear whether KIMCO has applied for NAIF funding but both levels of government have been given a copy of its proposal.
In a statement, a NAIF spokeswoman said it "treats business information regarding the status of potential investments as commercial in confidence".
Government planning to extend national park to Fitzroy River
Mr Pritchard said he wanted legislation to protect the Fitzroy River from any future proposals.
"What we're concerned about is that time and again we're seeing proposals, really damaging proposals that come back and threaten the river, and from our point of view what we need is legal protection for the river in perpetuity," he said.
In a statement, WA's Acting Environment Minister David Templeman said the Government planned to expand the nearby Geikie Gorge National Park to include the parts of the Fitzroy in question.
The Government plans to expand the nearby national park to include the parts of the Fitzroy in question.
"A national park along this portion of the Fitzroy River would provide the highest possible level of protection for the area's cultural heritage, landscapes, wildlife and habitat for species that rely directly on the river," he said.
"[It would] remove the potential for the river to be dammed as well as protect the river from direct environmental impacts, such as cattle grazing."