Animals that have been caught on camera in the forest. Photo: Supplied/GWRC
The Greater Wellington Regional Council are fencing off thousands of hectares of land to protect a "special forest" from deer, goats and pigs.
In the hills to the east of Wainuiomata lays 7400 hectares of native forest that has never been cut down due to its proximity to Wellington's source of water.
While the forest is home to native trees such as rata and rimu, the regional council's delivery director Jack Mace told RNZ there was a problem hiding under the branches.
"A lot of the seedling trees, a lot of the understory shrubs and small trees you'd expect to see just aren't there because they've been eaten out by deer, by goats and by pigs."
To deal with the problem the pests caused, the council plans to construct a predator fence that will stop such animals from getting into the area.
The project also included an increase in traps and the introduction of cameras across the forest.
The plan's total cost would be $5.9 million over a ten-year period.
A map is of where the fence will be. Photo: Supplied/GWRC
Mace said cameras in the forest, installed in December last year, showed how bad the problem was.
"We found that deer, pigs and goats are much more common even than we'd expected. They're turning up on just about every game camera."
He said the cameras also showed some positive signs.
"Pretty excitingly, a lot of the game cameras in there have picked up kiwi that were released by the Remutaka Forest Park Trust into the adjoining DOC land two decades ago."
During the construction of the fence the council would bring in hunters to kill the four-legged pest animals inside the forest, with the goal to fully eradicate deers, goats and pigs in the area.
He said the fence would not be like those seen at eco-sanctuaries such as Wellington's Zealandia, which stops possums and cats, but more like a steel mesh fence.
Mace said bringing back the forest's undergrowth - estimated to take five years - will have benefits.
"That'll provide for much better biodiversity in terms of better food sources for species that are within the forest in terms of a richer diversity of plants.
"It'll also help the forest to come back to be more resilient to big storms and climate change."
The forest was particularly unique in the Wellington region, he said.
"What makes it so special, I guess, is that it is really close to the city, really close to Wainuiomata, and you've got all these great big old trees that were never logged that are all intact."
Because the forest is a drinking water supply area it can't be accessed by the public.
All elements of the plan were expected to be completed by 2034.
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