West Tamar councillors Tim Woinarski and Peter Kearney said they had already received support for the school from those in the Legana area since the idea was made public yesterday.

The councillors said despite the Education Department deputy secretary Andrew Finch's dismissal of the proposal, they had the projected growth figures that show the area is expected to double in size in the next 10 years and the start of community support.

"This also gives the opportunity for the community to be part of planning a kinder to grade-12 school for Tasmania - and that could be done right, from the start," Cr Kearney said.

"We're not talking about building something overnight, but in the next three to five years."

Children in the area now travel to either Exeter or Riverside for school.

The school would be staged, starting with kindergarten and eventually offering year 12.

Cr Kearney said the move to extend high schools to year 12 to boost the state's poor retention rate, was already under way and this could be one school to offer it from the start.

Education Minister Nick McKim is reviewing submissions on a discussion paper on extending high schools to year 12.

Cr Woinarski said the proposal was an opportunity for a partnership between the department and local government for the wider Legana area that takes in Grindelwald, Bridgenorth and Rosevears.

"He (Mr Finch) needs to be getting out of Hobart and sitting down with the council here and seeing what we need," he said.

"Looking at 2010 enrolment trends doesn't do anything for the future needs here."

According to their projected growth figures, in the next 15 years there may be as many as 600 to 700 school-aged children living in the area, 400 of which would be of primary school age.

Opposition education spokesman Michael Ferguson said if there was support for a kindergarten to year- 12 model then it deserved serious consideration.

A department spokesman said demographic changes in school zones was monitored.

He said it was too early to comment on what may come out of the discussion paper on extending high schools.