Declining birth rates in parts of Birmingham mean more than a tenth of current primary school places will no longer exist by the end of the decade.
Council chiefs trying to deal with the demographic timebomb are attempting to find other ways of using schools in affected areas to stop them closing and teaching jobs being lost.
An analysis of population trends has revealed 9,000 of the city's 98,000 primary places will be empty within the next five years.
Most of the affected schools are located in the predominantly outer-ring areas of the city, such as Kings Norton, Northfield, Hall Green and Edgbaston, where birth rates are declining.
Meanwhile the authority faces a reverse problem in inner city wards such as Small Heath where the the largely ethnic population is growing but schools lack space to build.
Councillor Paul Tilsley (Lib Dem Sheldon), chairman of the council's education scrutiny committee, said: "With an ageing population in Birmingham we do have a problem of over-capacity due to the low birth rate, particularly of the host community.
"So we end up with schools in the wrong places. To try to ensure we can sustain schools we have to look far more imaginatively at how we use sites. Otherwise the danger is you lose them."
Government Ministers warned local authorities a year ago that schools with surplus places must either expand their services, merge or close. It claimed that in the
West Midlands a quarter of classroom seats were empty in 234 primary schools and 25 secondaries. It refused to name individual schools.
Les Lawrence (Con Northfield), Birmingham's cabinet member for education, admitted the authority faced a challenge preventing schools being lost.
"The important and fundamental priority must be to not release any of the educational assets in place because once they close they are gone for ever."
Coun Lawrence said the authority was already looking at ways of widening the role of schools in the community to safeguard their future.
It is hoped that private and public sector partners delivering services would help plug revenue gaps caused by falling rolls.
On the other side of the equation is a population boom of up to 28 per cent in inner city parts of Birmingham such as Sparkhill, Sparkbrook, Nechells and Bordesley Green.