Flood Recovery Minister Steph Cooke said it was pleasing the Wilsons River at Lismore had peaked at 11.4 metres, below the predicted record height of 12 metres.
"That's good news for the community this morning," she said.
"However we are regrouping as we look at recovery efforts as the water starts to recede.
"The weather system is making its way down the east coast, and we will see other communities impacted as it moves south over the next couple of days."
Some 30,000 people in NSW are affected by 20 evacuation orders issued by the NSW State Emergency Service, and 523 people were being housed at 20 evacuation centres still in operation, Ms Cooke said.
"The numbers are much less than what they were in the event of one month ago," she said.
"Nonetheless, those evacuation centres are there and they are a refuge for people who may not feel safe in their home, or who are the subject of an evacuation order or warning and don't have anywhere else to head."
Meanwhile the search continues for missing aged-care nurse Anita Brakel, whose car became trapped in floodwaters in Monaltrie, south of Lismore.
No trace of Ms Brakel or her car has been found despite searches involving Police Rescue, Water Police and NSW SES volunteers since she disappeared on Tuesday about 10pm.
A public appeal for information was launched on Wednesday.
"The rain has eased, but there is a lot of water to move through the rivers, catchments and streams, particularly in the Northern Rivers and also the Mid North Coast," Bureau of Meteorology forecaster Dean Narramore said.
Major flooding continues on the Wilsons, the Richmond, the Clarence, and the Orara rivers, while moderate flooding is continuing on the Hastings, Nambucca and further south along the Macleay, Bellinger and Kalang rivers.
"In some communities the sun is coming up this morning, (but) there is still major flooding ongoing," Mr Narramore said.
Flooding will continue in Lismore on Thursday but as levels fell below the levee the city centre would experience some relief, he said.
Major flooding is occurring at Coraki, Woodburn and Grafton, while Hastings and Nambucca were experiencing moderate flooding.
Mr Narramore said a severe wind and damaging surf warning was now in place from Kempsey on the Mid North Coast through to the Victorian border.
On Thursday morning, a candlelit vigil was held outside the prime minister's Sydney residence by a religious group urging the government to take action on climate change.
About 40 members of the Australian Religious Response to Climate Change, led by Rabbi George Mordecai gathered at Kirribilli House in solidarity with victims of the flooding disaster.
In the affected communities, anger is growing about the response from official agencies to the flood risk in the Northern Rivers.
"I was incredibly disappointed with the instructions from the SES," Lismore resident Nancy Casson told the Nine Network.
"We had an evacuation and then a non-evacuation, and then an evacuation again. I was so confused.
"I don't know what is lacking in their instructions to us. I don't know why they constantly get it wrong."