There are 71 new Covid-19 cases today in the community in Auckland, which director of public health Caroline McElnay said was "sobering but not unexpected".
And the number of daily cases is expected to double in the next 14 days.
Deputy Prime Minister Grant Robertson said officials expected case numbers in Auckland would rise, but that "they are rising quickly".
Robertson said the reproduction rate (the R value) is somewhere between 1.2 and 1.3 and that means cases will rise. The R value is the number of people which each case passed the virus to. Robertson said cases will head towards the "triple-digit mark" but assures they can be managed.
Robertson blamed people gathering in people's homes for the rise in cases and he urged everyone to follow alert level 3 rules. He stressed that alert level 3 was suitable for managing the outbreak when asked about the prospect of alert level 4.
"These gatherings inside people's homes are not allowed... my message today is clear. We need people in Auckland to stick to alert level 3 rules."
Robertson said "very few" cases are coming through work sites.
He said the outbreak is affecting people "in all parts of Auckland".
"This is no longer an outbreak about a couple of clusters, and a couple of suburbs," he said. It's affecting all of Auckland.
"Now is not the time for complacency," he said. He asked Aucklanders to get vaccinated and to not mingle with family and friends apart from in the outdoors.
Robertson said restrictions only work if everyone follows the rules. He said "it has never been more important to follow the basic rules". He hinted that rules could be beefed up if that was required. Robertson said prosecutions regarding the "gatherings" are up to police, but they can't be everywhere and that is not the solution to the problem The solution is people obeying the rules, he said.
In Auckland 87 per cent of people had had their first jab but this number had not increased for several days, Robertson said.
He said New Zealand has the lowest Covid hospitalisation and death rates in the OECD.
He said the country needs to stick to tried and true measures to avoid "carnage" like other countries.
Robertson said our level of hospitalisations remains relatively low, and ICU capacity "is fine" at the moment but of course people need to prepare for that to grow. He said it was not "an imminent problem".
Robertson said he encourages all New Zealanders to get vaccinated, and it's particularly important for community leaders to show leadership and get vaccinated. He said the Thames-Coromandel mayor has views that are not going to help us get vaccinated.
Robertson's message for Kiwis waiting for other vaccines: "Pfizer is a safe vaccine. All around the world millions of people have received it, and it is safe for them. It's the vaccine we are asking New Zealanders to use."
Robertson said it was still being investigated as to how two Auckland sex workers were able to reach Blenheim. They both have tested negative for Covid-19, Robertson said.
He said the boundary around Auckland is working well. He said the Ministry of Business Innovation and Employment has been asked to review their processes for exemptions.
Robertson said there are enough doses in New Zealand to be able to begin booster shots using the Pfizer vaccine, and work is ongoing on this.
Almost half of today's cases unlinked
Thirty-two of today's cases are yet to be epidemiologically linked, McElnay said. Of yesterday's 55 cases, 21 remain unlinked. One hundred and two cases from the past fortnight are unlinked.
McElnay said officials are not concerned that contact tracers in Auckland are becoming overwhelmed, as they contract out contact tracing to other parts of the country. She said this is normal practice.
McElnay said she has been assured contact tracers do have capacity to deal with the number of cases, and there is no sign of them being under pressure. Around 180 cases a day would start to put pressure on the system as a whole, she said, and they are looking at better use of technology to prepare to cope with an extra amount.
She said in this outbreak there are a lot more contacts with the cases because of the large households involved, and that's already been a part of the planning.
McElnay said the medium turnaround time for test results in Auckland is 24-26 hours and the expectation is that a test result is turned around in 24 to 48 hours.
Robertson said there will be times when those targets are not met, and he apologises for the distress the delay causes some people, but he said it is a rarity and not commonplace.
Positive wastewater test result in Te Awamutu
There are no new cases in Waikato today. Yesterday's two cases remain unlinked.
There were 3680 swabs taken in the region yesterday. In Waikato there was a positive detection in Te Awamutu on Tuesday, and follow-up sample results are still to come through. It's unclear if it's a new case or an old case "shedding the virus".
In Northland, 2145 swabs were taken yesterday and there are no positive cases.
Isolating at home
McElnay said a smaller number of cases, around 10 to 20 per cent could isolate at home to begin with, and that could increase to 60 per cent, but regional public health teams need to make a risk assessment.
McElnay said they are just confirming a process with ADHB to have more people staying at home.
Robertson said if there are higher volumes coming through MIQ, home isolation will need to be considered, and the Govt is preparing for that now. But it is not needed right now.
"If cases keep rising on the curve they are now... we will need to move in the coming weeks," Robertson said.
He said home isolation was always a part of the plan, but now it is "most definitely" part of the plan.
A risk-based assessment is underway right now on this, Robertson said, and it would involve people coming back from overseas.
Daily case numbers have been growing in Auckland for the past four days and Covid-19 Response Minister Chris Hipkins acknowledged yesterday that the virus is spreading across the city as an increasing number of locations of interest pop up.
Yesterday there were 53 new cases in Auckland and two in Waikato. On Tuesday 43 cases were reported in Auckland and three in Waikato and on Monday 35 new cases emerged in Auckland, none in Waikato.
It has been revealed one of two people who tested positive for the virus on Auckland's North Shore is self-isolating in a Kāinga Ora housing complex.
Meanwhile there are calls for authorities to crack down on rule breakers as a third Covid positive woman is hiding from police, after fleeing her home in Māngere. Police say she is known to authorities and the Herald understands police have been directed to take her straight to the Jet Park quarantine facility when she is found.
Today the Government is outlining its plans for hospitals to cope with a surge in cases as the country moves away from an elimination strategy, with worst-case scenarios showing the region including Auckland and Northland, could face more than 5000 cases a week in a Covid surge.
Auckland City, North Shore and Middlemore hospitals have already been hit by exposure events.
Two patients and two staff members tested positive after an exposure event at Dialysis Unit adjacent to North Shore Hospital and other staff have been stood down as a precaution. Staff were also stood down at Middlemore Hospital earlier this week after a positive case was detected.
Yesterday there were 32 people with Covid in hospital and six in ICU.
In Northland it's still unclear how widespread the virus is after two women who traveled to the area later became infected but failed to co-operate with contact tracers. A truck driver who traveled to the region has also become infected but a "limited scope of exposure" is expected from this case. No cases have been detected in the region this week.
New locations of interest listed on the Ministry of Health's website this morning include sites in Hamilton, Raglan and the Auckland suburbs of Birkenhead, Henderson, Manurewa, Greenlane and Onehunga.
There are 405 events involving 266 locations.
Northland, Auckland and Waikato remain in alert level 3 until Cabinet reviews settings on Monday. The rest of the country remains at alert level 2.