The Queensland Premier, Anna Bligh, is recalling the state cabinet to discuss the state's flood crisis.
After inspecting the situation in the city of Rockhampton, Ms Bligh said: "It looks like Rockhampton's in the middle of an inland sea. The amount of water coming down these river systems is nothing short of astonishing."
The Fitzroy River, which runs through the city, rose to nine metres on Sunday. Shopping carparks are filling with water as floodwater from the river edges closer to the city's two main bridges and just one street away from the CBD.
A flood peak of 9.4 metres (forecast for Wednesday) would affect an estimated 40% of Rockhampton.
The airport runway is already underwater and road links to the south and west are cut. Many houses in low-lying suburbs are largely submerged, and police are wading through chest-high water to ensure no one is left in them.
Evacuation centres are preparing for up to 1000 residents. Dozens have already moved into one centre, and hundreds of other people are staying with family and friends.
The Defence Force has stepped in to help deliver much-needed food to the city's 75,000 residents.
Grave concerns for smaller communities
Meanwhile, grave concerns are held for the communities of Surat and St George, south of Rockhampton.
Surat residents are preparing for record flooding, with the Balonne River expected to peak at 13 metres on Tuesday. The ABC reports it is currently 12 metres, with many roads already cut.
In St George, the water has reached 11.5 metres, and mayor Donna Stewart says they're ready for the worst.
The flood crisis already affects more than 200,000 people across an area the size of New South Wales. Twenty-two cities and towns have been inundated or isolated.
State Treasurer Andrew Fraser estimates the cost of the damage at more than A$1 billion. The state and federal governments have promised hundreds of millions of dollars in grants and assistance.
Man killed crossing flooded causeway
The flood-related death toll in Queensland has risen to 10, police say, following the recovery on Monday morning of the body of a man from a car at Aramac, inland from Rockhampton.
The man had been trying to cross a flooded causeway in his vehicle.
Police are again urging people not to drive through, along or across flooded roads, and to pay attention to 'Road closed' signs.
The body of a fisherman was also recovered on Monday morning from the flooded Boyne River near Gladstone and a woman died on Saturday when her car was swept off a causeway at Burketown.