Australian Prime Minister Julia Gillard has warned the floods which have caused widespread devastation in the northeast will take some time to recede.
She was visiting some of the worst-hit areas of Queensland state, where some 200,000 people have been affected.
She pledged to help improve flood protection for the city of Rockhampton, where water levels have fallen only slightly since peaking on Wednesday.
Levels are still rising in some places, including the town of St George.
Speaking to journalists in Rockhampton, Ms Gillard warned that the recovery would be slow.
"The scale of the floodwaters, the sheer size of this is best appreciated from the air, and we are talking about huge areas, lots of water, a lot of it still very fast-moving - and so it's going to be a long time back," she said.
"Flood waters do not subside quickly. It takes some time."
When asked what it would cost Australia's federal government, she said: "I've been very clear that we are talking about hundreds and hundreds of millions of dollars."
Earlier Ms Gillard visited St George, 450km (280 miles) west of the state capital Brisbane - one of a few towns where floodwaters are still rising.
Residents of the town had been told to prepare for the second record flood in less than a year.
But forecasters said on Saturday they expected the waters to peak about 60cm (2ft) lower than previously thought, threatening only a few homes.
Buildings were also expected to be flooded in the town of Maryborough, after a river burst its banks following heavy rain overnight.
Queensland Premier Anna Bligh warned that some communities could find themselves cut off by the floods in the coming days.
"We also know that there's many other towns downstream [from St George]... likely to be cut off and isolated for many weeks," she said.
"So getting supplies into these towns will continue to be a big priority."
The floods in Queensland have washed away roads and railways, destroyed crops and brought the coal industry to a near standstill.
Ms Bligh has estimated that the price of rebuilding homes, businesses and infrastructure, coupled with economic losses, could be as high as A$5bn (£3bn).