Australian Prime Minister Julia Gillard on Sunday urged residents of New South Wales to "keep safe" after at least two people were confirmed dead in heavy flooding across the state.
"Water is a dangerous thing. Deceptively dangerous. Even very low levels of water, if it's fast moving, can sweep people away," the prime minister said.
The heavy rain is said to have claimed the lives of two people, while thousands have been cut off by the floodwaters.
Local media reported that one of the victims was a 17-year-old who was sucked into a drainpipe as he was collecting golf balls in low-level floodwaters on Friday.
Meanwhile on Saturday it was also reported that the body of a man was found in his submerged car on a road about 20 kilometres (12.4 miles) northwest of Grafton, also on the New South Wales north coast.
Powerful winds have also been causing a problem.
In the state's coastal town of Kiama at least three homes were flattened and many others damaged in the overnight storm, local media reported.
The danger from floodwaters is not yet over either.
The north coast region, including the towns of Port Macquarie and Taree, remains under close watch along with the Hawkesbury-Nepean area west of Sydney, according to authorities.
Although State Emergency Services (SES) said the Macleay River had peaked lower than had been forecast in the northern New South Wales town of Kempsey, 350 kilometres north of Sydney, and the town appeared to have escaped major flooding.
The latest deluge comes just weeks after torrential rains in the wake of tropical cyclone Oswald flooded parts of Queensland and neighbouring New South Wales.