THE Hunter has 77 public schools operating above their enrolment caps, which are based on their number of permanent buildings.
Department of Education data released in response to questions from a parliamentary budget estimates committee shows 13 high schools and 64 primary schools spread across Maitland, Newcastle, Lake Macquarie, Cessnock, Port Stephens, Wallsend and the Upper Hunter have exceeded their caps, in some cases by hundreds of students.
Ashtonfield Public - which is preparing to undergo extension - is at 185 per cent capacity, with 600 students compared to its cap of 324.
Tighes Hill is at 177 per cent, Kahibah at 169 per cent, Branxton at 163 per cent and Soldiers Point at 155 per cent.
Maitland MP Jenny Aitchison said schools were at an average of "99 per cent capacity across my electorate".
"I have 11 schools over capacity in the fastest growing community in the state outside of Sydney," Ms Aitchison said. "It's just not good enough."
The government updated its enrolment policy last July to include centrally-set caps, as a consistent way for schools to manage enrolments from outside their local zones.
Demountables don't count towards the cap.
Principals set a buffer of places within the cap to accommodate local students enrolling throughout the year. They won't consider new non-local enrolments if they can't accommodate them below their buffer - and won't be given any additional accommodation to cater for increased numbers resulting from non-local enrolments.
A Department of Education spokesman said schools were "able to accommodate every local child who wishes to attend".
"The enrolment cap does not set a limit on the number of local students a school can enrol and is not the enrolment capacity of a school," he said.
"Schools with an enrolment at or above this cap are permitted to consider taking 'out of area' students only under exceptional circumstances. In cases of sustained and stable enrolment increases, the department provides additional permanent facilities, or new schools, as necessary."
NSW Primary Principals Association president Phil Seymour said it was a vexed problem.
"If you've got demountables for 15 to 20 years it's only because of the government's planning and not building anything for them that they're not considered in the cap," he said.
"We pushed hard saying if they were there for a fair amount of time they should be included in the cap."
He said while some principals appealed to their local directors, he couldn't confirm if and where changes had been allowed.
He said the government used a figure of 23.1 students per class for caps, but schools had 24 or more from year two.
Newcastle MP Tim Crakanthorp said many of the city's inner-city schools were "bursting at the seams".
"Tighes Hill Public School is more than 75 per cent over capacity, with more than a third of its classrooms demountable," he said.
"These figures only reinforce what we already knew - that the NSW government has failed to plan for growth in Newcastle schools.
"Enrolments are increasing and demountables are increasing with 26 across the Newcastle electorate.
"Meanwhile, two years after the Newcastle Education Precinct was announced with great fanfare, the consultation and masterplan for the project hasn't even been finalised."
Charlestown MP Jodie Harrison said "the inability of the Berejiklian Government to plan for the future has been revealed again".
"At this time, we are trying to reassure parents, students and teachers that it is safe to return to school," she said.
"However, the release of these figures - which shows our schools are bursting at the seams - will do little to reassure parents that it is safe to send their children back into the classroom.
"This government needs to invest in bricks and mortar to expand the capacity of existing state schools and to open new schools."