Some NSW residents told to flee rising floodwaters have been given the all-clear to return as heavy rainfall, which caused a major dam to spill, eases and water levels recede.
Spills have slowed from Warragamba dam but more than a dozen riverside communities have been warned the flooding emergency remains with the possibility some towns would continue to be isolated.
Water from the dam, southwest of Sydney, is making its way through the Hawkesbury-Nepean system, swelling rivers despite rain easing.
"That does not mean that the risk is not there because what we are going to see now is riverine flooding in many areas," acting State Emergency Service commissioner Debbie Platz told reporters on Saturday.
About 600 residents in low-lying areas of the Hawkesbury-Nepean Valley in northwest Sydney were told to evacuate on Friday night, including people in Sackville, Sackville North, Cumberland Reach, Lower Portland, Pitt Town, Pitt Town Bottoms, Cornwallis, Richmond, Cattai and Agnes Banks.
"If people are not evacuating, then we're asking them to please be prepared for many days of isolation," Ms Platz said.
The SES began doorknocking and moving resources into flood-prone areas as rain persisted throughout the week, Emergency Services Minister Jihad Dib said.
"The community has responded to the SES and to their warnings and advice, and when they were told to prepare to leave, they did make that preparation, when people were told to evacuate they did do that," he said.
The SES still conducted 13 flood rescues in the 24 hours to 5am on Saturday.
"People make silly decisions to drive through flooded waters ... you're putting yourself at risk, in danger, but you're also doing that to the volunteers," Mr Dib said.
More than 2000 volunteers have been involved in the SES operations.
Meanwhile, residents in the communities of Camden and Elderslie, about 65km southwest of Sydney, were told on Saturday they could return with caution after flooding reduced.
While Warragamba dam outflows have slowed it may take a few days to return to normal, WaterNSW chief executive Andrew George said.
"Inflows are declining though which is good news for the communities downstream," he said.
June is the third consecutive month the dam has spilled.
The Hawkesbury was rising toward major flood levels at North Richmond on Saturday morning but appeared to peak below that level at 10.5m shortly after 8am.
The river has continued to fall but is expected to remain above minor flood levels into Sunday.