More than 3000 homes were without power in Waiau. Photo: MAINPOWER / SUPPLIED
PowerNet warns restoring power to parts of Southland and Otago may take up to a week, after fierce winds downed or damaged lines.
The Southland and Clutha districts are under states of local emergency, as a result of the wild weather, with power cuts knocking out water and communications.
PowerNet Chief Executive Paul Blue said the company's focus on Friday had been on understanding the extent of the damage.
"Essentially the backbone of our Southland and south Otago electricity networks are broken - and we have to repair the backbone before we can begin to stand them back up."
Damage was caused by broken poles, trees coming down on lines, or flying debris from man-made structures, Blue said.
"The sheer scale of this damage means we will be working throughout the weekend, and well into next week before all customers have power back on. We are also working with neighbouring lines businesses and contractors to support our teams with the network restoration," he said.
Transpower executive general manager grid delivery Mark Ryall told RNZ's Checkpoint infrastructure in Southland, Dunedin, parts of Canterbury and the lower North Island were the hardest hit.
He said Transpower's network was fully operational, but power distribution companies' networks had been damaged.
"They were some extreme events, obviously a red weather event, and assets are designed to withstand certain winds," he said. "Obviously, things yesterday got a bit out of hand for some of the assets.
"Yesterday was about making things safe. Today, [the distributors] will be inspecting their network, helicopters in the air, working really hard to ascertain all the damage and then coming up with plans around how they can restore customers as quickly as possible.
"The weather looks good for the next couple of days, so hopefully that will help the teams working hard out in the field to get power restored."
Meanwhile, generators may be brought from Auckland to help get cellphone towers back online in Southland.
Telecommunications Forum chief executive Paul Brislen said it was working with telcos and the local lines company to get generators to areas most in need.
He said generators were on way to Southland from Christchurch and the forum was in talks with the National Emergency Management Agency to send more from Auckland.
"If this is going to be a multi-day event, we'll need more equipment moved into the region," said Brislen. "We are hoping we won't need it, but we always err on the side of caution."
People who needed to call emergency services on their cellphones should still try, even if their mobile said there was no network.
Brislen said 111 calls would use any available network, so if another provider's cell tower was working, the call would still connect.
He said cellphone towers could operate on back-up battery power, but it only lasted between 8-24 hours.
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