Contractors have described damage to the central North Island's power network as looking like a "war zone".
Around 400 properties are off the grid in parts of Rangitikei, Taupo and northern Hawke's Bay after snow blanketed the region.
Lines company Unison Networks says it could take weeks for power to be restored, with snow up to a metre deep in some places.
"What greeted us was devastation, to be frank," says spokesperson Danny Gough.
"We have 200 power poles down in the Rangitikei, Taupo plain area spread across - sort of - a 60km radius of network, and around about 24 poles up in the Hawke's Bay region. Look, that's extensive - some of the guys described it like a war zone.
The conditions workers were faced with (Unison Networks / Facebook)
"Along with the fallen poles, many are also broken, those poles still standing are twisted, and there are wires strewn across the landscape. It's real network devastation."
Civil Defence is sending teams into northern Hawke's Bay today to check on residents who are without power. Ian Macdonald from Hawke's Bay Civil Defence Emergency Management says many have been cut off since Saturday morning.
"We are going to be sending out some people to actually get into some those areas to find out if there are any welfare issues, if anybody needs any help."
Mr Macdonald expects it will be three days or more before power is restored.
"A lot of those people that live up there are quite hardy and they are used to these sorts of snow events, but this is quite a prolonged event, quite a serious event and the power could be off for quite a few days."
Mr Macdonald says anyone in urgent need of assistance should call 111, otherwise people can contact the Hastings District Council on 06 871 5000.
Animals will also be taken care of. Civil Defence will also be working with the Ministry of Primary Industries and East Coast Rural Support Trust on Monday to assess animal welfare needs.
People are also without power in Tutira, Esk Valley, Puketitiri, Waipunga and Patoka.
Mr Gough says Unison has started calling affected customers and has been working with Civil Defence, Federated Farmers, Dairy NZ and Rural Support.
"We are all going to work together and try and ensure our community gets through this challenging time, which will also involve looking at where generators might be of most benefit for community welfare."
(Unison Networks / Facebook)
Teams from Rotorua have been brought in to help out, as well as from other companies such as Northpower, Electrix and Horizon.
Tutira General Store co-owner Graeme McClinchie says locals are stocking up on essentials.
"A few people have come in and bought the odd bits and pieces and a couple of hot pies."
But he says the locals are prepared.
"I think that a lot of them have water pumps for showers and toilets and stuff like that. Without power they can't have a shower and so forth. They just hunkering down."
A small northern Hawke's Bay community is totally cut off after the weekend's wild weather washed out a rural road.
It's the second time in less than a year that McVicar has crumbled under torrential rain.
Mountain Valley Lodge owner Julie Batt says power could be out for another two or three days.
"We were able to get a generator across the gap yesterday... zip-lined one across so that we've got a bit of power for the fridge and a few cooking appliances."
She says a contractor's been sent in.
"He says he's going to put another road in actually down towards the river and across. He reckons that he'll have that in within a day once he can get in. That'll give us four-wheel drive access, and then another couple of days to two wheel drive before he sort of tackled the huge, gaping hole, although it's not as big as it was last time it happened, last September."
A large slip has closed State Highway 2 south of Whakatane.
The slip has covered the highway near the turnoff to Fraser Road, south of Taneatua. Police expect the road will be closed until midday when contractors can clear the slip.
State Highway 5, the Napier-Taupo Road, also remains closed, although Mr Macdonald hopes the road will be re-opened today.
The alternative route, via Gisborne or Palmerston North, adds four to five hours to a journey, so motorists are advised to plan ahead or delay travel when possible.
The Desert Road on SH1 is also closed, but the road between Taihape and Waiouru is now open.
The alternate Desert Road route via National Park on the other side of the mountains remains open.
Waimana Gorge on SH2 between Awakeri and Opotiki in Bay of Plenty is closed because of a slip, and delays are expected.
An alternative route has been set up on SH30 from Awakeri, through Whakatane to Ohope through to Wainui Rd, and back to SH2 at Kutarere.