The BBC reported according to new analysis, the number of children in care in England could reach almost 100,000 by 2025.
Research commissioned by county councils said the figure would represent a 36% rise in a decade.
And the expected increase is already putting “unprecedented pressure” on local authority’s budgets.
The chairman of the County Councils Network (CCN), Tim Oliver, will explain the impact of the rising number of children in care to his organisation’s annual conference in Marlow later.
Putting up a child in a children’s home costs more than £4,000 per week on average in England.
In 2015, 69,000 children in England were looked after by councils – but by March 2020, the figure was 80,080.
Projections for the CCN estimate that it could reach 95,000 in just over three years’ time.
The rise is being explained by, among other things, a shrinking number of people willing to be foster carers.
The CCN’s lead for children and Conservative leader of East Sussex County Council, Keith Glazier, said with local authorities spending their money on the growing need, councils “aren’t having the ability to go out and do more early intervention with families, to try and keep families together, rather than having to take children into care”.
He added: “At the end of the day we have to ensure children are safe, that is the prime purpose”.