A low pressure system is dumping heavy rain across some parts of central and southern Queensland of Australia already hard hit by the flood crisis, the Australian Associated Press (AAP) reported on Thursday.

More torrential rain is expected to continue into the weekend, according to the weather forecast.

The central Queensland city of Rockhampton, still in the grip of its worst flood in almost 60 years, saw heavy rain overnight and more of the same is expected into the weekend.

The Fitzroy River in the city peaked at 9.2 meters on Wednesday, flooding 200 homes and affecting 3000 other properties.

Rockhampton Mayor Brad Carter has said the city could take a year to get back on its feet, and it could be up to two weeks before residents could return to flooded homes.

About 660 km south of Rockhampton, the southern inland town of St George is braced for a flood peak of at least 14 meters on Monday or Tuesday, with more rain expected to exacerbate the situation.

Australia's Deputy Premier Paul Lucas is expected to visit St George later on Thursday.