Another weapon in the battle to stop the spread of kauri dieback in the Waipoua kauri sanctuary has been installed at the start to a popular walking track.

Visitors now have to walk through a cleaning station to get on to the 20-minute forest track past the Four Sisters cluster to Te Matua Ngahere, the second biggest kauri tree in New Zealand.

The booth at the entrance to the track replaces a shoe bath system, which a survey in the peak season estimated only 20 per cent of visitors used, DOC's Kauri Coast operations manager Diane Sanderson said.

On the day the Advocate was at the site, a visitor to Northland from Christchurch, Diane Pankhurst, said she was delighted to see strong measures taken to stem kauri dieback.


"If this is what it takes, then it needs to be here, and these stations should be in all the places where they are most needed," Ms Pankhurst said. "I knew of kauri dieback before we came up here but I didn't realise it was so prevalent."

The new regime means people cannot get on to or leave the track without walking through the footwear steriliser. Visitors have to spray water on their soles, rub them on a brush on the floor and then walk across sterilising pads. The waste water is captured in a tank and emptied each week, Ms Sanderson said.

The bright, sign-covered, walk-through cleaning booth is the fourth and final of the prototype to be installed at high-risk kauri forest sites by the multi-agency kauri dieback team.

Just along the road, the entrance to the largest kauri Tane Mahuta also carries warning signs and a more passive footwear cleaning system, but the tree is considered less vulnerable because walkers can only approach it via a boardwalk.

The fungus-like organism that causes the dieback is spread by soil movement, whether trapped in the tread of shoes, on vehicles or equipment carried from one kauri site to another.

The highest concentration of the fatal tree disease is in the Waitakere Ranges, west of Auckland, with the Waipoua Forest also showing significant infestation.

Kauri dieback infects the tree roots and prevents it taking up nutrients. While it is unlikely a cure will be found, Department of Conservation (DOC), Ministry of Primary Industries (MPI), iwi organisations, local government and the other agencies involved are using the cleaning stations and public education to prevent its spread.

From Waikato to Far North, 200 walking tracks in DOC reserves have been identified as needing protective action. The upgrade of those tracks, including the new cleaning station in Waipoua, is being paid for out of the Government's $26million (over three years) response to kauri dieback.