Flooding disaster across east Australia

State Emergency Services volunteers survey the Queanbeyan River. Photo / Getty Images

SYDNEY - Four deaths have been reported in severe flooding which has hit the eastern states of Australia this week.

The latest victim was in Queensland. Police have recovered the body of a 15-year-old boy who drowned at a flooded water hole on the Sunshine Coast.

Yesterday a man's body was retrieved from a river at Nebo, west of Mackay. Witnesses said the impatient driver passed other cars stopped on the roadside waiting for the floodwaters to subside.

An 81-year-old man also died when his ute was swept off a flooded causeway and into a creek on Friday night.

And a 55-year-old woman died when her car was swept off a flooded roadway near Dysart, north-west of Rockhampton in central Queensland, last week.

Reports are calling NSW's floods the worst inundation to hit the state in 50 years.

The swollen Queanbeyan River yesterday peaked in the NSW city neighbouring Canberra but residents forced to evacuate were not expected to be allowed home until late last night at the earliest.

If there is more rain they could be stranded for even longer.

The river cut Queanbeyan in half when it peaked at 8.4m in the afternoon. It had risen 3m in less than three hours.

The city has been declared a natural disaster area, taking the total number of declared areas across NSW to 30.

"The flood peak, we think, has already occurred on the river," NSW Emergency Services Minister Steve Whan said in Queanbeyan.

"At 8.4m we've had the town cut in half. We've had around 100 houses and businesses which have been asked to evacuate."

A number of houses and businesses were inundated and 10 people had to be rescued by boat from Trinculo Place, which runs alongside the Queanbeyan River just south of the King's Highway.

An upstream river gauge indicates the river is now falling dramatically.

But NSW emergency services commissioner Murray Kear said it would take a further six hours "for the water to get down to any level where we could be confident to allow people back into their homes".

Residents were given little warning of the flood because the river rose extraordinarily fast.

Water flowed from the nearby Googong Reservoir, which was already full before it received 103mm in the 22 hours to 9am yesterday.

The weather bureau is predicting the rain band that wreaked havoc in Queanbeyan will move north.

Authorities are worried it will pose problems for areas such as Coonamble in northwestern NSW.

The deluge that hit Queanbeyan and the nearby hills will also boost the volume of water flowing into the already swollen Murrumbidgee system. That will add, over the coming days, to the woes being experienced in Wagga Wagga and further downstream.

In Victoria, a man swept away by floodwaters north of Melbourne clung to a tree for five hours before he was rescued.

Police said the 51-year-old was walking home at about midnight in Whittlesea when he tried to wade across a waterway that had risen in a downpour and was swept 100m downstream. He managed to grab hold of a tree branch and hung on until about 5am, when he was found by people who heard his cries for help.

Water police rescued the man and he was taken to hospital, where he is expected to make a full recovery.

State Emergency Service workers took about 400 calls for help for flooding and building damage in Victoria's northeast.

- AAP