The Bureau of Meteorology has forecast widespread rain across northeast NSW including the Northern Rivers and Mid North Coast, from tomorrow.
The wet weather may extend further south as the week goes on.
Rain falls of of 10-40mm a day are likely, but up to 50-150mm is possible.
Minister for Emergency Services and Resilience and Minister for Flood Recovery Steph Cooke said the land around Northern Rivers remains “saturated.”
“I understand you have been through a hell of a lot already, the next few days are going to be particularly challenging,” she said.
A total of 22 people died in the floods in south-east Queensland, northern New South Wales and the Sydney area at the end of last month and early this month.
More than 3,600 homes in the NSW northern rivers region were deemed uninhabitable.
Acting Premier Paul Toole said the news would be “tough” for those communities.
“There are many people that aren’t going to welcome the news that we are going to be talking about,” he said.
“But I want them to know that we will stand side by side with them once this weather event has gone through.
“It’s going to take years, and we are going to stand side by side with those communities as they rebuild.”
NSW SES Assistant Commissioner Nicole Hogan warned of flash flooding and landslips.
“Our catchments are very wet, and our dams are full, so it will not take a lot for floods to occur,” Ms Hogan said.
“We need people to be mindful of their flood risks and be prepared.”
“In some areas floods may be different than previous or expected flooding due to the impact of recent events. People need to monitor the weather conditions closely and be prepared to act early.”
Over the last few days, some places in the Northern Rivers have already seen up to 100-200mm of rain.
BoM’s Jane Golding said most of that rainfall fell in just a few hours.
“That’s a marker of how much moisture the atmosphere is holding at the moment,” she said.