"Cyclone Debbie was large in size, vicious in its intensity and has caused enormous havoc." according to the Anglican Bishop of North Queensland, Bishop Bill Ray.
Half a dozen rivers in south-east Queensland have been pushed to major flood levels with the threat expected to remain in place for days.
Heavy storms and floods caused by cyclone Debbie is hindering rescue works in Australia, as authorities on Friday feared residents being trapped by the rising water, a media report said.
Many rivers flooded, including the Logan and the Albert in south Queensland and the Wilsons and Tweed in NSW.
"Levels in the Logan River are generally the highest since 1974, and continue to rise near Logan (at Waterford) until Saturday morning".
In the Hunter Valley, the body of a 64-year-old woman was found submerged in four metres of water on Friday afternoon, the day after her vehicle was swept off a causeway at Gungal, about 170 kilometres north-west of Newcastle.
The preparations come after the body of Eagleby man Nelson Raebel was found by emergency crews on Saturday afternoon, becoming the Queensland's first victim following ex-tropical Cyclone Debbie.
Ms Berejikilian said she was "anxious" to get to flood-affected areas in the state's north on Monday, but urged residents not to return to their homes until directed. "While I have also been told that the problem has now been rectified, there are probably hundreds of people who have been denied when they are stressed out and hurting, and it is truly disgraceful", he said.
In the state of New South Wales, authorities made nearly 400 flood rescues and received about 2,000 calls for help since Wednesday night, public broadcaster ABC reported.
Verry said what remains of the cyclone has moved off Australia's eastern coast.
"It is the worst I have ever seen I have to admit".
Rockhampton in central Queensland is still bracing for its worst flooding since February 1954, with the water forecast to peak as high as 9.4m on Wednesday, submerging about 5400 properties including 3000 homes.
"It's unbelievable, mate", said one man, speaking from a boat in the flooded town of Lismore, New South Wales.
In areas further north where the cyclone made landfall, water and power were still being restored.
The Mackay district's sugar crops have also been hit hard by the cyclone's wrath, with industry figures estimating $150 million damage had been done to local canegrowers' operations in the area.