The "inevitable" move to the red traffic light setting has disappointed one Tauranga principal, who says events and gatherings that "grow the culture of the college" will have to be cancelled.
While the move to red was a "sensible approach" it meant a pōwhiri to welcome new students to the 2022 school year could not go ahead.
Prime Minister Jacinda Ardern announced the move on Sunday morning and expected the country to stay at red for "some weeks".
Tauranga Boys' College principal Robert Mangan said the move to red was "inevitable" and a "sensible approach".
He said staff were "working through" changes to the school programme that would help ensure student health and safety.
The biggest concern for Mangan was school ceremonies that "grow the culture of the college" would not go ahead under the red traffic light.
"We are concerned about the impact of a loss of those important rituals, traditions and ceremonies. It is disappointing that we can't have a pōwhiri welcome for our 500 new Year 9 students.
"But we have got to be pragmatic, we are in a pandemic."
He also believed it would decrease school attendance due to "heightened" anxiety among some in the school community.
Staff would "continue to support learning remotely", making online work available to those who were anxious about attending school and unwell.
He was grateful that the decision was made ahead of school starting, allowing time to "get messaging out to the wider parent community".
Staff and students would be expected to supply their own masks but some would be available on-site for those who don't bring face coverings.
At this traffic light setting students Years 4 and up must wear face coverings indoors and when in close contact with others.
This included classrooms, assemblies and when accessing public venues.
In a bulletin issued to school leaders on Sunday, it said further guidance on the impact of Omicron would be provided following Cabinet's meeting today
It said principals were advised to prepare for delivering on-site and distance learning once school returned.
"I appreciate that some in your communities will have concerns about attending on-site, as we have seen previously when settings are at their highest."
Western Bay of Plenty Principals' Association president Suzanne Billington said schools were preparing for Omicron's arrival and were waiting on Ministry guidelines for more certainty.
"We do expect this is going to happen, so we will manage it as best we can as we go."
Billington, who was also the principal of Tauriko School, expected the majority of children to attend school when the year started.
"The only reason we would expect children to be off-site is if they were getting tested, if they had symptoms, or if they had complex medical needs."
Distance learning support would be available to those unable to attend school but Billington said this could get harder as Covid cases increase.
"The difficulty will be as this hits us and we have staff or multiple children off-site. Because teachers in classrooms can't be providing feedback to people at home while they are teaching at school.
"Schools are working extremely hard to ensure that students have the best learning they can get in a difficult situation."
Tauranga Intermediate principal Cameron Mitchell said he was waiting on advice from Cabinet for more details about how schools would run at the new setting.
"All schools have got very clear health and safety guidelines they follow and they are set up to keep everybody safe."
He said Tauranga Intermediate staff were looking forward to welcoming students back "as per normal".
Tauranga-based Labour list MP Jan Tinetti said she wanted kids to spend as much time in the classroom as they could.
"We really want to make sure that our kids are getting as much face-to-face schooling as possible, because there's been so much disruption.
She said the vaccination campaign was the "number one defence" in schools, as well as mask-wearing for those students Year 4 and up.
She said her colleagues in Auckland had reported their young people wearing masks "really well" in the lead-up to Christmas.
"That was something I had no qualms about - I knew that our young people could step up to the mark on that."
For the Bay of Plenty, she said the warm weather meant classrooms could be well-ventilated with open windows and doors, as well as outdoor teaching and distancing where possible.