Schools whose decile ratings increase could see savage cuts to government funding.
Decile ratings were last reviewed after the 2006 census.
Silverstream South School principal Elizabeth Cleverley said there had since been a boom in property subdivisions in Mosgiel, which had significantly changed the mix of residents in the area.
The change meant more affluent families were moving into the area and her decile 4 school could jump up the rankings.''
Without a doubt, it will make a difference to our government funding. I suspect that if we were to change, it could cut $10,000 to $20,000 annually off our government funding,'' she said.
Otago Primary Principals' Association chairwoman and Abbotsford School principal Stephanie Madden said a large subdivision had sprung up near her school in recent years and she believed its 7 decile rating might also be raised.
The review could have a similar impact on many schools in the region, she said.
Ministry of Education head of student achievement Graham Stoop said last time there was a decile recalculation, one third of schools gained a higher decile rating, one-third gained a lower rating, and one-third remained in the same decile.
''Approximately 11% of total school operational funding comes from decile-related funding.
''We recognise that any reduction in funding will be an adjustment, which is why this time we have introduced an 18-month transition period for any reductions.
''Increases in funding will, however, take effect much sooner, at the start of the 2015 school year.
''We will be working closely with schools to give them any support they need to adjust to changes.''
A school's decile rating indicates the extent to which it draws its pupils from low socio-economic communities.
Decile 1 schools are the 10% of New Zealand schools with the highest proportion of pupils from low socio-economic communities and decile 10 schools are the 10% of schools with the lowest proportion of these pupils.
The lower a school's decile rating, the more Government funding it gets.
The increased funding of lower decile schools is to provide additional resources to support their pupils' learning needs.
A decile does not indicate the overall socio-economic mix of the pupils attending a school, or measure the standard of education delivered at a school. Deciles are simply a way in which the Ministry of Education allocates funding to schools.
Mrs Madden said if a school's decile ranking rose, its operational grants funding would be decreased, which meant less funds for services such as reading recovery, access to professional development and support programmes such as social workers in schools.
''A change of decile can have a significant impact on a school's financial situation and on their ability to provide support for their pupils.
''Schools will be anxious to receive the results of the latest review.''
Miss Cleverley said there was nothing schools could do if their decile was changed by the ministry.
If her school's rating fell, she and the board of trustees would have to be proactive and reconsider how they would fund things like support staff and extracurricular activities.
''It will be a challenge.''
''I'm definitely going to have to put my thinking cap on,'' she said.
How they rate
Decile ratings for Otago schools
Rating Number of schools
Decile 1 0
Decile 2 2
Decile 3 5
Decile 4 14
Decile 5 14
Decile 6 24
Decile 7 22
Decile 8 23
Decile 9 19
Decile 10 23
