Emergency services were called to Bretti Reserve on Thunderbolts Way in Bretti, around 100km west of Taree, after the Barnard River broke its banks around 10pm overnight.

Police were told an SUV towing a caravan was swept into the floodwaters after an elderly driver attempted to cross the causeway.

Despite extensive search efforts overnight, the man and his car has not been found.

The search involved SES members, PolAir and the NSW Rural Fire Service.

Around 22 people were deemed safe but were unable to leave the campground after it became surrounded by floodwaters at around 3am.

Air crews landed at the campground however the campers did not want to be evacuate, police said.

Floodwaters have since started receding and a search for the man will resume.

Emergency services have reminded drivers not to drive through floodwaters.