Areas of the Illawarra and South Coast could be declared disaster areas on Tuesday, according to Emergency Minister David Elliott.
NSW Premier Gladys Berejiklian and Mr Elliott visited SES headquarters in Wollongong on Monday for a briefing about the weekend's heavy rains and flooding.
Mr Elliott said the disaster designation will be applied to a number of Local Government Areas on Tuesday.
"Tomorrow we expect that a number of Local Government Areas will be given natural disaster declarations which will allow for extra funding, extra support and of course the appropriate response from our emergency services," Mr Elliott said.
The NSW Premier added that the Illawarra and South Coast areas could potentially be among those disaster areas.
Ms Berejiklian also extended her sympathies to South Coast communities now dealing with floods after weeks of bushfires.
READ MORE: Flood-affected schools set to re-open
"I can't imagine what communities like Lake Conjola and parts of Bega are going through, having to now withstand the impacts of torrential rain having just come through the fires," she said.
"Nothing takes away from what you've suffered already. I can't imagine the concern now on top of the trauma of the fires, to now have to worry about flooding. But please know we're here to support you, we're here to ensure you receive what you need to get you through this difficult time."
SES Commissioner Carlene York said the rains created extra risks for those South Coast areas already burnt out by bushfires.
"The trees can become quite unstable through the burning and the foliage on the ground is missing, so you find that some areas that don't normally flood can get flash flooding," Commissioner York said.
"Some trees are at risk of falling over with the amount of water, so I would encourage residents to really be careful around those firegrounds and make sure they're thinking about their safety at all times."