The SES said the vehicle began to float while they were crossing the causeway near the entrance to Farrer high school.

“The pair managed to get out of the vehicle but then drifted more than 500m down the Peel River towards Tamworth,” he said.

The boy, discovered clinging to a tree by emergency service workers, was quickly rescued.

It took significantly longer to recover the

driver.

“The woman was rescued by a boat crew which was later forced to find shelter on an embankment because of debris on the water,” the SES spokesman said.

Another crew was called to the10-year-old.

“The boat crew with the woman called in the helicopter for assistance after they became increasingly concerned for her welfare,” he said.

She was then airlifted to safety.

“Both (the boy and his grandmother) were transported in stable conditions, with minor injuries, to Tamworth Hospital.”