A big drink for Tane Mahuta

One of the world's most famous trees is dying for a drink but Waipoua iwi say quenching Tane Mahuta's thirst could hasten rather than hold off the giant's demise.

New Zealand's biggest tree is visited by thousands of tourists a year and is an icon of the county's largest remaining kauri forest.

Waipoua Forest Trust conservator Stephen King plans to dump 40,000 litres of water around the tree, with half of that task already carried out.

Mr King said the tree is shedding abnormal amounts of foliage and showing other signs of stress caused by the 70-year record drought. The forest has had only a tenth of its normal rainfall so far this year.

"Once the tree is very stressed then [disease] can take a hold," Mr King said.

Trust members have trucked the water from nearby Wairau Stream tributaries. The water would simulate an autumn dousing and prevent shock when the region's normal heavy winter rainfall arrived, he said.

But while the novel thirst quencher has raised international awareness about kauri vulnerability and the drought's far reaching effects, the forest's ancestral guardians are not impressed.

Te Roroa representatives say they were not consulted about the plan. As part of the Treaty of Waitangi claim settlement of 2008, Te Roroa were recognised as the forest's guardians and partners with Department of Conservation in its management.

Will Ngakuru, iwi representative on the national multi-agency team investigating kauri dieback, said he only heard of Mr King's drought-buster through the media.

The Department of Conservation, which were notified, did not properly consult with Te Roroa, he said.

Iwi were concerned about any potential to spread the kauri killer disease Phytophthora taxon Agathis (PTA or kauri dieback), Mr Ngakuru said.

He agreed the situation was a case of damned if you do and damned if you don't, with Tane Mahuta's health having to be weighed up against risks for the surrounding forest. "We don't know enough kauri dieback yet."