The Government has imposed enrolment restrictions on schools in and around Christchurch to prevent overcrowding.
Most of the city's 163 schools are expected to reopen this week following the 22 February earthquake, but at least 20 will not.
A Christchurch principal says enrolments have been crazy as people try to enrol their children in schools that are open.
But the Ministry of Education has used emergency powers granted last week to impose enrolment caps on the state and integrated schools in Christchurch, Selwyn and Waimakariri.
The new rules give first preference to students enrolled before the earthquake and suspends school zones and ballots for out-of-zone children.
The ministry told schools the change will help them operate effectively until rolls stabilise.
Canterbury Primary Principals Association president John Bangma says the rules will help schools manage a complicated situation.
He says they make it easier for schools to turn students away, something they could not normally do without an enrolment zone.
Havelock North school takes some students
The Ministry of Education has given special dispensation to Woodford House in Havelock North to take on nine Christchurch girls affected by the earthquake.
Principal Jackie Barron says permission was required, as accommodating the girls will mean the capped roll of 325 pupils is exceeded.
She says some of them will only be at Woodford for a week or two, but others will stay for the rest of the first term.
Mrs Barron says the girls range from year 8 to 13.
Options to help students sitting exams
Education Minister Anne Tolley says the Government is looking at options to help secondary students in Christchurch sitting NCEA exams this year.
As of Tuesday, about 62% of early childhood centres and 70% of schools had reopened following the earthquake. Mrs Tolley expects 95% of schools to be open by next week.
Mrs Tolley says the focus at the moment is on getting schools open and back to normal routines, but some students will have missed a month of school and making up that lost time will be the next issue that has to be dealt with.
The ministry is looking at making up some of the time students have missed during school holidays, or providing extra tuition.