A final fundraising push is underway in Nelson to start work on the biggest conservation sanctuary in the South Island.
Conservationists hope to establish a sanctuary within a huge pest-proof fence at the head of Nelson's Brook Valley.
A trust has already raised $3 million for the Brook Waimarama Sanctuary and hopes to reach its target of $4.7 million by the end of the year.
By 2015, it hopes to fill the area with a wide range of wildlife including kiwi, tuatara, weka, bats and burrow-nesting seabirds, creating a popular tourist destination and wildlife retreat.
It would be the second-largest sanctuary in New Zealand after Maungatautari ecological island in Waikato, and would be three times bigger than Zealandia in Wellington.
Brook Waimarama Sanctuary general manager Hudson Dodd is confident the venture will not have similar financial struggles as Zealandia, which has been bailed out by ratepayers in recent years.
"We have the benefit of learning from that experience, and recognising that we don't want to repeat that mistake ... we're raising the funds to build our facilities in advance."
Nelson City Council is carrying out a feasibility study to work out whether ratepayers will support it to the tune of $1 million and more cash is coming from Tasman District Council, lotteries grants and from local businesses and residents.
Although the fence project has already proved very popular in Nelson, some argue the money would be better spent on more trapping, and there are worries the site is exposed to high winds and flooding.
Local pest-trapper Bryce Buckland says the land is unstable and prone to slips so a fence might need constant work - and money - to maintain.
If the trust reaches its target of $4.7 million, it's hoped work on the fence will begin in November.