Parts of western Sydney have been spared after less rain than expected fell in the area, but major flooding continues with more rain to come.
About 500,000 people had been told to evacuate their homes in recent days around NSW.
Some 130,000 homes in the path of a spilling Warragamba dam in the Hawkesbury-Nepean region in western Sydney were given some reprieve on Thursday afternoon with the news that flooding is no longer likely to be worse than it was in March 2021.
With dozens of evacuation orders in place around the state it remains to be seen whether residents in some of them will be given the all clear to return home on Friday.
A forecast for 600 gigalitres of water to spill over the dam wall daily was revised down to between 300 and 350 gigalitres, after less rain than expected fell in the catchment area.
Western Sydney is still experiencing major flooding, but the rivers are expected to peak below the March 2021 flood.
The Bureau of Meteorology said on Thursday night major flooding was expected at Windsor as the Hawkesbury and Lower Nepean Rivers continued to rise.
The SES early on Friday morning urged residents of the Eastern Part of Wisemans Ferry to prepare to evacuate properties along Singleton Road from the Wisemans Ferry town centre to the western edge of Laughtondale in the next few hours.
Wallacia experienced moderate flooding on Thursday afternoon following peaks on the Nepean River at Menangle and Camden.
Further north, the Richmond River delivered major flooding at Coraki, Bungawalbyn and Woodburn on Thursday, with peaks near the record March 1974 flood level, but Casino and Kyogle fell back below the minor flood level.
The SES responded to more than 2500 requests for assistance and conducted 144 flood rescues in the 24 hours until 5pm on Thursday.
Sydney avoided the heaviest rains on Thursday, with more intense falls to the north in the Hunter region and to the south in the Illawarra.
While the low pressure system that brought hundreds of millimetres of rain and devastating flooding to multiple areas in Qld and NSW over the past week was expected to ease overnight into Friday, more severe weather could be on the way.
Another cold front on the way from Victoria will bring more rain and severe weather into the weekend, Bureau meteorologist Jackson Browne warned on Thursday.
More rain could cause renewed river rises around the state, the BOM warns.