Only three of Taupo's schools have spare capacity, with the rest either full or expecting more students soon, and Taupo-nui-a-Tia College instructed to implement a zone.
Three Taupo primary schools are already zoned with a fourth, Wairakei, in the process of zoning.
Principals said the current pressure points were at Taupo Intermediate and the town's two colleges, but more families arriving in Taupo and new subdivisions would soon mean a rise in primary school rolls too.
Associate Minister of Education Tim Macindoe announced in Taupo last week that Taupo-nui-a-Tia College would receive two new classrooms, and Taupo Intermediate three, but the new classrooms would be 12 to 18 months away, meaning it could be the second half of 2019 before schools saw any relief on overcrowding.
Taupo-nui-a-Tia College principal Peter Moyle said his school was at capacity after steady roll growth over the past five years and improved student retention.
It began the year with 1150 students.
"At the moment we're coping but our projections indicate that the roll is steadily going to increase and that's going to put pressure on ... our projection is by 2020 we'll have 1200 [students] so we need to control that.
"We've been instructed to implement a zone and we're still waiting for data from the [Education] ministry at this stage," he said.
Taupo-nui-a-Tia had a zone several years ago, which extended south to the Napier-Taupo Rd and Mr Moyle expected any new one would be similar but did not know whether it would be in place at the beginning of 2018.
"A zone takes about three terms to implement and we haven't started that process yet. We'll need to consult with other schools and parents and it has to be approved by the ministry as well."
Other schools around Taupo, including Wairakei School and Taupo Primary School, were also at capacity. Wairakei had consulted on an enrolment zone and although principal Paula Farquhar was unavailable for comment, she said in a school newsletter on May 30 that the school was waiting to hear from the Education Ministry.
Taupo Primary School principal Cushla Seamer said she was a classroom short and hoped for additional space so a class would not have to move into the library when new entrants arrived in terms three and four.
She said she had been told the school would be receiving some replacement buildings, but not when. Taupo Primary implemented a school zone in 2012 and tightened it further last year.
While Hilltop School and Tauhara College were both also growing, Waipahihi School principal Tim Lovelock said his school was expecting a big rise in student numbers when new subdivisions between Richmond Heights and Taupo Airport opened up, with the first houses expected to be built by mid-2018.
"In two or three years time, who knows what we'll look like," he said.
Tauhara College principal Keith Buntting said his college's roll of 620 was approaching capacity.
"What's interesting for us that our Year 9 growth is pretty regular but we're seeing people coming into the community across all year levels."
Mountview School principal Carmel Hoetawa said her school and Tauhara Primary, both unzoned, suffered from a perception that a zoned school was more desirable, despite committed teachers and excellent Education Review Office reports.
"My main concern with the zoning in this town is that it's made two low socio-economic areas," she said.
"Our last Education Review Office review was in the top 15 per cent for a five-year review. We're a really good school, we know we're a really good school, but you can't change people's perceptions."
She expected that as out-of-zone students and siblings moved through local primary schools, more families would send their children to the unzoned schools.
Both have some capacity - Mrs Hoetawa estimated her school could take two more classrooms, and Tauhara Primary principal Tracy Fraser said her school had space for one more class.