The SES said evacuated residents of Pitt Town North, Pitt Town Bottoms, Cornwallis, North Richmond, Agnes Banks, Grono's Point and Freemans Reach should not return until authorities give the all clear.

"Even as flood waters recede, utilities will continue to be impacted and there will likely be extensive debris including hazardous materials and potentially unsafe roads," the SES said in a statement on Sunday.

However, evacuation orders for the southern part of Wilberforce and eastern part of South Windsor - more townships around the Hawkesbury River - were cancelled on Sunday afternoon.

Evacuation orders on the NSW mid-north coast and near Moree have also been lifted, with eight "all clear" return notices issued as river levels fall.

Rapid Damage Assessments are taking place through western and northwest Sydney in areas including Penrith, the Hills District and Hawkesbury.

"The teams out in the field are working closely with the community and local services to begin the recovery process," Allison Flaxman of the SES said.

Endeavour Energy said about 370 flood-affected properties in NSW were still without power as of 3pm on Sunday.

A major flood warning remains in place for the Barwon River in northwest NSW, as well as moderate warnings for the Bogan River in the state's central west, and the Macintyre and Weir Rivers near the Queensland border.

NSW Education said 13 schools within the state - 12 public and one non-government - would be closed on Monday because of local flooding and road closures.

"It may take some days to fully assess any damage to some schools," a spokesman said in a statement.

The SES has received more than 23,000 calls for help from the public, and volunteers have attended more than 13,000 jobs since the floods began.

Grants and bank loans will be made available to businesses in flood-affected areas to fund their recovery, Prime Minister Scott Morrison announced.

Mr Morrison said on Saturday the federal government will underwrite 80 per cent of bank loans of up to $5 million for small and medium businesses in the flood-affected areas, with repayments to start two years into the loan.

The measure is an extension of a support program available for COVID-affected firms.

"This is about backing the businesses and producers that are backing themselves to get back on their feet," Mr Morrison said.

The loans are on top of a recovery grants program jointly funded by the federal and NSW governments. Small businesses can get up to $50,000 and primary producers up to $75,000 if they have been affected by floods.

As tens of thousands of people across NSW return to their homes, an emergency services task force is tackling the clean-up, including Australian Defence Force personnel, the NSW Rural Fire Service, and Fire and Rescue NSW.

The Australian Red Cross is warning of a lack of access to mental health help, and urging people affected by the floods to take steps to protect their psychological, as well as physical, wellbeing.

Meanwhile, the search for an elderly woman continues after police pulled her empty car from the swollen Barrington River on Thursday.

Australian Associated Press