Greater Wellington Regional Council wants government funding to develop a Lower Hutt bird "super sanctuary,"
The Puketaha fenced eco-sanctuary would be built in Wainuiomata on 3000 hectares of native bush.
A feasibility study has shown that once the area is predator-fenced and pests eradicated, it could provide sufficient habitat to shift the threat status of kākāpo, rowi kiwi and hihi.
The research also showed it would aid the recovery of biodiversity across up to 40,000 hectares of the Remutaka Range.
The study indicated that around $42 million is required over a 10-year period to obtain resource consents, construct the fence and associated infrastructure, eradicate pests within the confined area and introduce the native birds.
The Regional Council has requested new funding to allow the Department of Conservation, Regional Council and Taranaki Whanui to complete detailed designs and obtain resource consents for the proposal.
This information would then inform the development of a future business case for a budget funding request.
The council hasn't detailed how much funding would be needed.
Conservationist and eco-sancturary Zealandia founder Jim Lynch described the proposal to RNZ as a "super sanctuary."
"Apart from Maungatautari in Cambridge, it would be the biggest sanctuary in New Zealand and the difference with it, is its right in the middle of a very large, forested area -- about 50,000 hectares."
Lynch said the facility would be able to house every threatened species that is indigenous to the area including the kākāpo, and its surrounding forest would create an optimum halo effect.
"It would be a major push to help our most threatened species get off these offshore islands and establish really sizeable permanent populations."
Greater Wellington Regional Council chair Daran Ponter said they put the proposition in front of the last Government.
"They were interested, and the proposal sort of was on the cusp of being considered but election cycles have sort of stood against us."
Ponter said that the project was a bipartisan proposal so they would be looking to get the new Conservation Minister on board with it.
"We previously had Chris Bishop and other National Ministers up there."
Conservation Minister, Tama Potaka provided RNZ with the following statement on the project.
"I will consider the matter with advice from DOC who have in principle been supportive of the proposal but as you know the Government has many urgent priorities."