Watercare’s Hunua Ranges regeneration project takes shape


More than 120,000 native trees and shrubs are being planted in the Hunua Ranges this winter – the first of many planting seasons that will see Watercare restore former forestry land to its natural glory.

The Hunua Ranges are home to some of Auckland’s most important water sources. Our four Hunua dams supply about two thirds of the city’s drinking water.

We bought a 1900-hectare forestry right in the ranges last year and worked with the Auckland Council to amend it so that commercial forestry operations will end decades earlier than they otherwise would have.

Chief executive Raveen Jaduram says the purchase was about protecting Auckland’s water sources.

“The acquisition of the forestry right enables us to have better control over the activities in our Hunua water catchments.

“Commercial forestry activities in our catchments do pose risks. Sloped areas where younger pine trees are growing are more vulnerable to slips. We saw evidence of this during the Tasman Tempest weather event in March 2017. Cosseys dam, which had had the most forestry activity, was by far the worst affected by massive landslips, which deposited silt into the dam and muddied our raw water.

“Now, under our management, no more pines will be planted, and the area will be progressively restored to its natural state for the people of Auckland.”

Early planting and trials were carried out last year, but this is the first full-scale planting season. Planting crews are averaging about 5000 plants a day to plant 120,000 trees over 22 hectares.

Species include manuka, kanuka, mahoe, mako mako (wineberry), kohuhu (black matipo), puahou (five finger), karamu (coprosma robusta) and harakeke (flax).

Headworks manager Joseph Chaloner-Warman says the plants were grown from seeds eco-sourced from the existing native vegetation growing in the area.

“We gathered the seed from the existing natives close to the planting zone, and then used local nurseries to grow them until they were ready to be planted.”

The area being planted this year was where pine trees were most recently harvested. It lies in the Mangatāwhiri catchment.

Chaloner-Warman says he’s proud to be managing the regeneration project.

“I grew up hunting and fishing in the native bush in New Zealand, so to be transforming this land into native bush is personally rewarding. I’m a bit of a greenie at heart.

“The Hunua Range is the jewel in the crown of the Auckland Region. I feel privileged that I can see behind the gate, and one day this area will be opened up for all Aucklanders to enjoy.”

Mayor Phil Goff will join us for an official celebration of the end of the planting season on September 28.