Almost $30 million has been allocated to "chock-a-block" Bay schools in the last four years to help cope with rapidly growing rolls.
Some packed Bay schools have resorted to using existing spaces in novel ways to cope with their growth - one is using its sports shed as a music room and others have used their libraries as temporary classrooms.
Figures released to the Bay of Plenty Times under the Official Information Act show the Ministry of Education allocated more than $29 million in infrastructure funding in the last four years to help schools cater for roll growth.
The figures showed Tauranga schools enrolled so many pupils that they reached almost 100 per cent of their official classroom capacity by the middle of 2018, the most of any city.
As of July 1, 2018, 25,624 students were enrolled in Tauranga schools.
Oropi School principal Andrew King said the funding allowed the school, that had about 320 pupils, to build four extra classrooms.
"Our building capacity has not met the demand at all. Everything is being used up as classrooms at the moment."
King said the school was using its multi-purpose room as a temporary classroom and the PE shed was doubling as a music room.
Roll growth had gradually increased in nine years, but more noticeably in the last four years, as he said an influx of young families had moved to the area.
Omokoroa Point School principal Vicki Knell said the school was funded for three new roll growth classrooms.
"It has been long overdue," she said. "We are chock-a-block. Every class is at full capacity. We will probably have to give up our library towards the end of this year. We simply don't have another space."
Knell said the school was expected to reach 300 pupils this year, and she believed the roll growth was due to a demographic change in Ōmōkoroa and an increase in population.
"There are a lot of new subdivisions and a lot of young families building new homes," she said.
Tauranga Boys' College principal Robert Mangan said the school would soon build a new 12-classroom block.
Mangan said the Government had previously announced $4.5m for nine extra classrooms to cater for roll growth.
"Those nine classrooms have been essential for us to cope with roll growth," he said.
But Mangan said some ageing classrooms would soon be bulldozed and the extra funds would help build 12 extra classrooms.
Matt Simeon of the Western Bay of Plenty Principals' Association said the ministry was taking a proactive approach to cater for Tauranga's future roll growth.
"We are conscious of a growing city and the demands being placed on the infrastructure on our schools," he said.
The Pillans Point School principal said his school had been funded to build six extra classrooms.
"Last year we had a huge number of 5-year-olds enrol," he said. "We have about two families each week come in and want to enrol their children."
Ministry of Education deputy secretary of sector enablement and support Katrina Casey said the ministry's job was to manage school infrastructure by planning for growth and population shifts both in the short and long-term.
"To do this, we consider a range of information including population projections, local council information, enrolment data and how well school properties are utilised," she said.
Casey said the Ministry had developed a draft national education growth plan which identified anticipated location and growth patterns in school children between now and 2030, and identified what should be considered to meet the growth.
Tauranga and the Western Bay were two of six high growth areas nationwide, she said.
More than $81m was allocated for redevelopment in the last four years, with $51.6m funded in the last financial year.
A $47 million Government investment into fixing Otumoetai College's leaky buildings was announced last year.
Principal Russell Gordon said the school was built on a "compromised" site more than 50 years ago.
In 1965, the school was built between two hills partly on a 6m-wide valley that runs diagonally through the current site, he said.
"The weight of the buildings due to roll growth means our buildings are sinking and in the event of an earthquake we would be in dire straits," he said.
The redevelopment will include demolishing and replacing four classroom blocks - 57 teaching spaces - and the school library.