The intense rainfall moved south on Friday, but communities around the NSW mid-north coast remain cut off and it will take some time to recover once floodwaters recede.
Prime Minister Anthony Albanese and Premier Chris Minns planned to visit hard-hit Taree after flooding killed four people and isolated thousands.
But their attempt to meet affected locals was aborted, further highlighting the town's isolation by its second major flood in four years.
"We've heard word from local MPs and businesses that they've had a torrid three days, incredibly difficult circumstances," Mr Minns said from Maitland.
"We know it will take a long time to get that community back up on its feet."
Port Macquarie local Margret Meagher told AAP the town took 18 months to recover from its last major flood and it would be important for the community to band together.
"People feel they're isolated, so that's where the whole community spirit is so pivotal," she said.
More than 1600 insurance claims have already been made, according to the Insurance Council of Australia.
"Insurers stand ready to serve customers through the oncoming recovery period," chief executive Andrew Hall said.
A fourth death - and third involving a driver - from the record-breaking floods was confirmed after a man in his late 70s appeared to be swept off a causeway at Nana Glen near Coffs Harbour.
A man died at a flooded home near Taree, as did a driver west of Port Macquarie and a 60-year-old woman near Coffs Harbour.
A man missing in Nymboida has been located but police have not ruled out floods as a factor in the disappearance of another man in Bellingen.
But hundreds of people would be dead without SES volunteers, the premier said.
"We're in deep, deep gratitude to those people," Mr Minns said.
The prime minister announced assistance grants of $180 per person or $900 for families would roll out in coming days.
Those unable to work in the hardest-hit areas will have access to disaster recovery allowance from Monday.
"Tragically, we're seeing more extreme weather events," Mr Albanese said.
The SES has conducted 736 flood rescues.
But with the rate of rescue requests decreasing, volunteers are focusing on getting supplies to the 50,000 people isolated by floodwaters.
Locals in Port Macquarie took things into their own hands, boating food to people in the city's northern suburbs.
The slow-moving trough that dumped months of rain over the mid-north coast also brought heavy falls south to the Hunter, Blue Mountains, Sydney and Southern Highlands.
Drier conditions are forecast in the flood-ridden areas but residents are not out of danger.
"There are waters still moving quite quickly through the river systems, a lot of debris around so it's quite dangerous," Bureau of Meteorology's Jane Golding said.
Increased wind on Monday and Tuesday could also uproot trees and buildings from sodden soil.
The SES had 167 warnings in place on Friday afternoon, with low-lying parts of Sydney also warned to prepare for evacuations.
Police warned Sydney drivers to exercise caution in the wet after two deaths overnight - including a 95-year-old hit by a car in Liverpool.
Disaster assistance has been expanded, with 19 areas now eligible for support.
People who want to donate to those affected can do so via GIVIT, a non-profit partnered with the government to support flood-hit communities.