The prime minister, meanwhile, has lamented the loss of a "way of life" for flooded business owners in regional NSW who face another round of rebuilding and recovery.

The SES has started assessing damage in affected areas, with most rivers having peaked and evacuation orders being lifted.

At least 1300 properties have been assessed for damage so far, with 75 declared "potentially uninhabitable".

There are just under 9000 people still under evacuation orders, with 76,000 either permitted to return home or released from warnings.

Evacuation orders were lifted in several northwestern Sydney areas late on Thursday including South Creek at Mulgrave and the Hawkesbury River from Wisemans Ferry to Brooklyn and in Vineyard.

Most remaining orders are around Moree, the Clarence River in northern NSW and the Hawkesbury-Nepean Valley in northwest Sydney.

Bureau of Meteorology Flood Manager Justin Robinson on Friday told reporters those residents would soon return home.

The situation across the entire Hawkesbury-Nepean Valley was expected to ease by Monday and river levels in Moree were dropping fast, he said.

Major flooding continued on Friday morning at Maclean in the northern rivers region, while the situation in Grafton and Ulmarra has eased.

Now the focus turns to inland rivers, through which huge volumes of water will flow into the Menindee Lakes.

A flood peak is moving through Boggabilla on the Queensland border and will work its way through the Barwon and Darling rivers over the next three months.

Mr Robinson warned that although the sun was out, people should still avoid flooded rivers.

"Having high rivers, a sunny weekend, children playing ... is a pretty dangerous combination," he said.

"It's always at the end of the event where people get a bit more relaxed and start to make small mistakes."

The SES said on Friday there had been 12,500 requests for help since last week - 618 in the previous 24 hours - and 1000 flood rescues.

About 500 SES volunteers remain in the field.

Meanwhile the search for an elderly mid north coast woman has intensified after police pulled her car from the swollen Barrington River on Thursday.

Adele Morrison was last seen at a shopping centre in Gloucester after leaving home in Port Macquarie on March 16.

A man died in Glenorie in northwest Sydney on Wednesday.

Mostly clear skies are forecast across the state for the next week but the east coast low season has only just begun, the bureau warned.

Premier Gladys Berejiklian and Prime Minister Scott Morrison, meanwhile, on Friday spent time with emergency workers in Wauchope, west of Port Macquarie.

Mr Morrison said the floods likely washed away a "way of life" for many, who would need years to recover. This was compounded by the lingering effects of the 2019-20 bushfire season.

The federal and NSW government will each pay 50 per cent of flood recovery costs, with assistance now on offer to 63 local government areas.

"It's not just that businesses have lost their equipment, generators ... these are businesses that families have built up over a lifetime," he told reporters.

"It's not just the loss of income, it is the loss of a way of life they have worked so hard to build and that is just heartbreaking."

Grants of up to $75,000 will be available to affected primary producers while small businesses can access up to $50,000.

Australian Associated Press