Persistent flood waters along the New South Wales north coast appear to be moving inland as rivers rise and thousands of residents have become isolated by the closing of roads and driveways.

The State Emergency Service (SES) has called on the residents affected to take extra safety measures and relocate livestock and equipment to higher ground even as the flooding is not expected to rise too high.

SES spokesman Phil Campbell told ABC there is also flooding inland in the state's west, north of Bourke, affecting the 300-member Indigenous community of Goodooga, where officials came for a visit on Sunday to talk to Aboriginal elders and check on their communities after having been isolated due to the floodwaters.

Flash floods continue to cut dozens of roads from Mount Isa in the north to the NSW border and the east-west railway line at Emerald.

Meanwhile, the Paroo River is expected to reach flood levels near the NSW border next weekend, with water levels similar to that of the major autumn flood in 2010, News.com.au reported.

Even as it appears conditions are beginning to clear in the southeast, a monsoon trough is expected to develop off Cairns on Monday.

Bureau hydrologist Jeff Perkins told the media key areas of concern were Emerald, Roma and Paroo.

In the far southwest, record falls were registered in the Quilpie district at Cowley, which had 146mm in 24 hours, its highest rainfall since 1884. Nearby Quilpeta also had a record fall of 160mm.

"We've also got floods in the Bulloo, Maranoa, Paroo and Condamine that we're keeping a close eye on," Perkins told News.com.au.