Shoalhaven Mayor Amanda Findley has urged residents to act now if they live in an area at risk of flood.
A number of flood warnings are in place for parts of the Shoalhaven.
Although there has not been official advice to evacuate at this time, Mayor Findley has urged residents at risk not to wait.
"If you think you may need to leave, leave early," she said.
"Don't wait for a doorknock in the middle of the night. Make arrangements and leave now to family or friends."
Mayor Findley said anyone without family or friends to go to can register for assistance at their local police station.
She told those who need to prepare their homes to make the most of remaining daylight hours.
"Be smart, take responsibility, and help your neighbours," she said.
"Particularly if they are older or new to the area and haven't experienced local flooding before."
The council is on red alert and an emergency operations centre with all relevant agencies is open to respond to emergencies.
For emergency help in floods and storms, call the NSW State Emergency Service on 132 500. In life threatening situations call triple zero (000) immediately.