Watch: Prime Minister Chris Hipkins with latest Cyclone Gabrielle update

The government is getting a better picture of the damage across the North Island today and the devastation is widespread, Prime Minister Chris Hipkins says.

Cyclone Gabrielle has moved east of the country but MetService says heavy rain will continue to hit central New Zealand until Thursday with high waves along East Coast.

Hipkins said "What is clear is that the devastation is widespread and it's taken a toll beyond property and livelihoods, to people".

The grief of the loved ones who have died will be unimaginable, he said.

Today's immediate focus has been undertaking life saving missions, getting telecommunications and power back on as soon as possible, conducting aerial surveys to understand the extend of the damage, deploying emergency supplies and getting communications assets to area that need them, he said.

"This has been an enormous logistic effort ably lead by NEMA and the Defence Force."

There are seven outstanding requests for evacuation in the Hawke's Bay region. None have been identified as critical and all those who were on roofs have been rescued, he said.

More than 9000 people are expected to have been displaced across the region and there are 3000 in civil defence centres.

Police reported 1442 people are unaccounted for, mainly in the Hawke's Bay, as at 2.30pm, Hipkins said.

There have been 1111 people reported as found and Hipkins said there was likely to be a cross over in these numbers.

"We expect the majority of these people will be accounted for however there are several people missing for whom police do hold grave concerns."

All local bridges between Napier and Hastings are out. Access to these areas has been re-established for emergency services and lifeline supplies via SH51.

Napier and Gisborne airports opened again today and Air NZ deployed a special assistance flight carrying communications support emergency supplies and airport operational staff into Gisborne today.

NZDF now has over 700 people involved in efforts. There are four aircraft, seven helicopters, two ships and 58 trucks.

The army has moved a logistics support team of 100 people and 30 vehicles, deploying to Hawke's Bay. Three NH90 helicopters have been conducting evacuations in Hawke's Bay today. A Hercules is conducting reconnaissance along the east coast to survey the damage.

The HMNZS Manawanui sailed from Auckland at 5.30pm with supplies destined for Tairāwhiti, and was expected to arrive at first light in Gisborne. It will deliver water supplies to small communities on its way to Gisborne.

The HMNZS Te Mana will sail tomorrow to Napier, supplying Wairoa with water and other essential supplies. A member of the national emergency team has been on the ground in Wairoa today to help establish communications.

An NH90 has moved teams into Wairoa and a rapid relief team is working to provide a drop of bottled water for 3000 people via helicopter, planned to arrive this evening.

The team is also establishing a BBQ in Wairoa this evening to cater for approx 3000 people. They will start cooking when they arrive and only stop if they run out of people to feed or run out of food, Hipkins says. They're aiming to provide 300-500 food packages tomorrow morning.

The defence force will tomorrow move a water treatement facility into Wairoa to supply drinking water with the HMNZS Tamana delivering further drinking water.

In Gisborne, people are asked to conserve fresh water. Bottled water is on the way for Wairoa, Hipkins says.

"I know the need in the affected communities is great and we're doing all that we can across a major response effort to get the support and supplies to where they are needed the most," Hipkins says.

Hipkins says emergency services have requested people who have been evacuated from their homes not return until they have been given the all clear.

"Whilst the weather may improve in some areas and it may appear on the surface to be safe, if you haven't been given clearance to go back there is a reason for that."

There is "significant concern" for some in the Hawke's Bay, Hipkins says.

Eskdale is one of the areas they are wanting to get better information on, he says.

"There's clearly still quite a bit that we don't know. There are still some areas where we need to get more information, in some cases we need to get people on the ground before we'll get a really accurate picture of that.

"Hour by hour more information is coming in."

Hipkins says more rain coming may complicate rescue and response efforts as there could be additional incidents that get added to the tally of things needing to be responded to.

Hipkins says the hospital in Hawke's Bay, located in Hastings, is continuing to operate but has staffing issues as not all staff can be there at the moment.

Acute care is available in Napier and hospital teams are working with primary care.

"If people have a serious health issue, they should call 111 and through that they'll be able to get the best information on how they can access the acute care wherever it is that they are."

Hipkins says he intends to travel as soon as he is able to, it is safe to do so and his presence wouldn't detract from the immediate rescue efforts. "I don't want to be diverting resources to transport me around when those resources are required for the emergency response.

"In terms of my response to it, it is one of gratitude to the first responders who are on the ground doing an incredible job, enormous empathy for those who are experiencing significant disruption and resolve that we will absolutely get through this," Hipkins says.

Power and communications infrastructure update

Energy Minister Megan Woods says companies are working to restore electricity as soon as possible.

Since yesterday 65,000 households have had power restored. As of 2.30pm, there were 160,000 households without power.

In Hawke's Bay there are 60,000 people without power.

In Tairāwhiti and Wairoa there were 15,000 people as at 2.30pm without power.

There are still high winds in some places with blocked roads making restoration unsafe or inaccessible at this point, she said. Restoration may not be able to begin until later in the week in some places, she said.

Lines companies are working together to get crew to places they are needed, the government is assisting them to get crew and equipment up to Northland in the first instance and looking at what support is required in other locations.

Woods has asked electricity retailers to look at whether they have people and engineering expertise to help the effort.

In Hawke's Bay, with the substation out of action, Transpower is working on a bypass to connect another substation to allow more customers to get reconnected.

The level of damage to electricity infrastructure has not been seen since Cyclone Bola, she said.

The government has set up a fuel sector coordinating entity under the national fuel plan comprising of fuel companies, retailers, MBIE and NEMA.

"This is giving a picture of open fuel stations in affected areas so that local civil defence emergency management can access fuel to undertake response activities," Woods said.

"The issues are not about the supply of fuel but a result of power being off at certain stations and/or an inability to access them by road meaning that vehicles can't refuel."

Fuel is considered a lifeline service, she said.

SH2 to Napier has now been opened to lifeline services, including fuel. Mini tankers are loading at Napier and supplying emergency services with diesel as required. The Wiri terminal and Masden Point terminal remain open and operational. The Whangārei Harbour is opening today and import ships are scheduled to arrive tomorrow.

Digital Economy and Communications Minister Ginny Andersen said the three main areas impacted the most to connectivity are Northland, Coromandel and Hawke's Bay. Gisborne also has some impact.

Anderson says there have been five main breaks in fibre across the country, two have been restored - Coromandel and north of Taupō.

In Northland crews are working to extend the generator reach. Getting power back up is also key, she says. In Coromandel, connectivity should improve in the next 48 hours.

In Gisborne, there are two major fibre outages, there are intermediatory measures being made with satellite and generators to provide a short term limited connectivity. Voice and text will be installed but further ability to use the internet required fibre.

Communications providers are working to provide and interim measure of overlaying fibre over land to restore fibre connection to Gisborne. It is anticipated this will take a couple of days to be in place.

In Napier, generators are being used to provide cellphone connectivity as quickly as possible.

The telecommunications emergency forum has been stood up and has been meeting daily.

The cell network is undamaged, the main issue is just getting power on, Anderson says.

NZ's 'largest emergency housing project' ever

Megan Woods, as minister for housing, says there are a range of ways the government needs to approach the situation.

"We are working with community housing providers and Kaianga Ora around our public housing stocks in terms of our tenants there. We're also looking at housing assessments as they come through but probably the most useful figures that we're monitoring are those people who are now accessing the temporary accommodation service.

"We are very aware that this is the largest emergency housing project that the country will have ever had to undertake."

It will be a larger job that after the Christchurch earthquakes.

National Emergency Management Agency (NEMA) Director of Emergency Management Roger Ball said the agency's understanding was that somewhere between 10 and 15 percent of the township of Wairoa was affected by flooding.

A full assessment of the area is still needed, Ball says.

People are able to move around and get emergency support.

"Obviously it's a significant indundation of the township but those people are being looked after by civil defence locally and external resources are coming and we're putting in another three Star Link units."

NEMA spoke with Tairāwhiti civil defence this morning and have a reasonable picture of isolated communities there.

These communities are being well supported by their networks, Civil Defence felt.

National state of emergency: What you need to know

• The New Zealand government has declared a National State of Emergency, to assist in the response to Cyclone Gabrielle.
• The declaration will apply to the six regions that have already declared a local State of Emergency: Northland, Auckland, Tairāwhiti, Bay of Plenty, Waikato, and Hawke's Bay.
• A national state of emergency gives the national controller legal authority to apply further resources across the country and set priorities in support of a national level response.

National Emergency Management Agency advice:

• Put safety first. Don't take any chances. Act quickly if you see rising water. Floods and flash floods can happen quickly. If you see rising water do not wait for official warnings. Head for higher ground and stay away from floodwater.
• Stay at home if it is safe to do so. But have an evacuation plan in case your home becomes unsafe to stay in.
• If you have evacuated, please stay where you are until you are given the all-clear to go home.
• People should stay up to date with the forecasts from MetService and continue to follow the advice of Civil Defence and emergency services.
• Do not try to walk, play, swim, or drive in floodwater: even water just 15 centimetres deep can sweep you off your feet, and half a metre of water will carry away most vehicles. Flood water is often contaminated and can make you sick.