Community wellbeing board chair Izzi Seccombe said the care system was in crisis, with a funding gap growing by at least £700m a year.
As a result, councils are being forced to make tough decisions about the services they provide and Seccombe warned that without the support of unpaid carers from relatives and friends, the situation would further deteriorate.
If the government was to introduce a £25m council tax rebate fund in the forthcoming Spending Review, this could unlock as much as 250,000 hours of unpaid care per week, the LGA said, potentially saving up to £220m a year.
"Unpaid carers play a pivotal role in the adult social care system and it is crucial we continue to attract them and recognise and reward the sterling work they do. They are the unsung heroes of the care system,” Seccombe said.
"In addition, they give invaluable help to some of the most vulnerable people in society. They save taxpayers money by relieving the pressure on health and care services.”
