Unison workers fixing power lines in Maraenui, Napier, 20 February 2023. Photo: RNZ / Tim Brown
The Electricity Networks Association says half of the outages during Cyclone Gabrielle could have been avoided if there had been better tree management.
"It's not just the cyclone, this happens reasonably frequently," Electricity Networks Association chief executive Graeme Peters said.
"We're estimating this is a more than $100,000 fix."
More than 100,000 households lost power over the course of the cyclone - more than 9000 were still without power on Wednesday morning.
"Half of the outages could have been avoided if we had effective management of trees around powerlines," Peters said.
The association wants the government to review regulations on managing trees around power lines.
"At the moment they can grow to around half a metre of a line, now that's really hopeless because the branches break into lines, they blow into lines, overhanging branches fall into lines or entire trees just fall on lines."
Decisions should be made based on assessments of the number of customers potentially impacted, the type of tree and whether it's likely to be exposed to severe weather, he said.
He said over the past week they have seen hundreds of instances of branches breaking into lines.
It was the responsibility of the lines company to notify the property owner in the first instance, and they would pay for this, he said. The second time was up to the owner.
"That process doesn't work because we have to identify who the tree owner is and it's really difficult to do that. We'd rather much work with the land owner...to deal with those issues."
It didn't mean removing lots of trees but exotic trees and forestry in particular caused problems, he said.
"Half of the outages could have been avoided if we had effective management of trees around powerlines" - Electricity Networks Association chief executive Graeme Peters