Tens of thousands of Aucklanders were left without power last week after strong winds brought down powerlines.
Power provider Vector said the main culprit was trees and branches falling onto lines. Vector chief executive Simon Mackenzie said crews out repairing the lines had never seen such damage but Vector was limited in what it could do when trees encroached on its lines.
“The regulations as they stand is that if a tree is near the line then we have to cut it once and then it becomes the responsibility of whoever owns the tree.
“Depending on whether the lines are on the low or the high voltage network, Vector can only cut a keyhole around the lines of either half a metre, or 1.5 metres,” Mr Mackenzie said.
That did not make much difference when the wind picked up, he said.
“When wind speeds get over 70kph, no matter how much vegetation trimming you’ve done, trees start swaying significantly, and we get to 140kph then you get massive trees being uprooted that could have been across the road or 20 metres away from the line and there’s just nothing that can be done.”
The rules about tree trimming near powerlines are covered in the Electricity Regulations which have not been updated since 2003.