The area of trees in the Waipahihi Botanical Gardens in Taupō that needs to be trimmed or felled. The peg at the bottom shows the distance to where the trees must be trimmed. Video / Dan Hutchinson
Volunteer gardeners at Taupō's Waipahihi Botanical gardens are horrified that mature native trees must be “decapitated” because they have grown into the flight path for the local airport.
The gardens and the airport had their beginnings at about the same time, with the first planting day on October 1, 1966, five years after land 2km to the south was set aside for the airport.
Planted on a hill that forms one of the highest points in the Taupō urban area, the 35-hectare gardens are unique in that people can drive around them and park at various points to walk tracks and explore a huge array of native and exotic trees and other plants.
However, the latest five-yearly obstruction limitation survey (OLS), which is required by all airport authorities, shows the trees at the top of the gardens have intruded into the flight path, and must be topped or removed.
Airport manager Wayne Wootton said they were bound by the Civil Aviation Authority rules and had no choice in the matter.
He said it was about safety because when pilots were flying in conditions where they relied on their instruments, they had to know where the obstacles were, which was why they had five-yearly surveys.
“If anything is protruding through, the plane has to land further down the runway.”
The land upon which the gardens were planted is owned by the Department of Conservation and managed by the Waipahihi Botanical Society.
Society chairman Graeme Robinson said trimming the trees went “against the grain” of what they were trying to do.
Waipahihi Botanical Society chairman Graeme Robinson stands amongst a copse of trees that will have to be trimmed or felled to ensure they do not encroach on the flight path to the airport. Photo / Dan Hutchinson
“One of our buzzwords is that it is an emerging forest and it is not going to emerge if they are decapitated.”
He said the trees were planted in the first 10-15 years of the gardens being established and the offending ones were a mixture of native beech, rimu and tōtara.
“Anybody who is interested in native tree species would find a priceless collection of tree species here.”
The 20-30 volunteer gardeners are mostly in their 70s and 80s. Those who planted the trees that need to be topped had likely passed away long ago, Robinson said.
“We manage it, enhance it and look after it and provide it to the community free of charge and live entirely on donations from like-minded people.”
Wootton said arborists contracted by the Taupō District Council had been out to assess the trees, of which there were about 10 that needed urgent attention. They would assess if the trees could be successfully trimmed or would have to come down.
He said it would need to be done this year before the trees grew any more.
Some of the trees have only reached 60 per cent of their full height but were already up to 15 metres tall. The tallest ones needed to lose about 12 metres of height to ensure they will not protrude until at least 2030.
Robinson said if the trees did have to be trimmed, how would it be done without damaging the surrounding area and who would pay for it?
They had already lost several large specimens as a result of Cyclone Gabrielle but fortunately there was “no mass damage”.
“We can deal with cyclones, but aeroplanes is something else.”
The arborists have yet to table their report to the Taupō Airport Authority Committee.
Several other trees outside the gardens also needed to come down or have already been felled.
To date, Wharewaka East Limited and Land Corp Farming Limited have provided costings to the airport committee to remove trees on their land and the Taupō District Council parks team has already taken down a tree on council land that was highlighted in the OLS survey.
