A tree specialist with about 30 years' experience dealing with poplars and willows has questioned whether the trees recently felled near the Alexandra bridge on State Highway 8 were rotten.
The trees were felled by New Zealand Transport Agency (NZTA) contractors. At the time, the NZTA's area manager Central Otago, John Jarvis, said the trees were rotten and posed a risk to the bridge and anyone or thing under them.
However, Barrie Wills, of Central Environmental Services in Alexandra, said he had since inspected the stumps and not all were rotten. He questioned whether they posed more than a minimal risk to structure, life or limb and said an independent report could have revealed that.
"Yes, poplar branches do weaken and can fall, especially after snow, but larger side branches could easily have been lopped, negating that risk.
"Certainly some were a little rotten and the odd one was hollowing out - that is when they do pose a risk and should be removed. But, in my opinion, the majority were fine.
"Some sap stain was evident in the core of most stumps, but that is typical of many trees and poplars in particular."
Mr Wills said the trees could have been judiciously thinned rather than blanket felled.
He said the bridge was at greater risk of damage from heavy vehicular traffic, such as digger booms left elevated, which has already happened, than from trees.
"However, removing larger trees from the vicinity of the old bridge piers, which could readily be damaged, was probably timely. That said, a few younger trunks could easily have been left."
Mr Jarvis said before the trees were felled NZTA identified several that posed a risk of being blown over and damaging or obstructing the steel-structure highway bridge.
Consultation was undertaken with the Central Otago District Council and the extent of work, including removing some smaller trees, was agreed, he said.
CODC parks and reserves manager Grahame Smail said he had received positive feedback.
"I think the majority of people are happy. Personally, I think it's a great improvement because it shows off the old bridge piers. I suppose it's like a work of art - some people will like what they see and others won't.
"On top of that, the work was paid for by taxpayers, rather than by the council."
Mr Smail said CODC staff were working on a draft tree management strategy.
