A senior official has described the flooding in Queensland, Australia, as a disaster of "biblical proportions".
State Treasurer Andrew Fraser said the economic impact would be severe, with huge costs compounded by lost income from mining, farming and tourism.
Rockhampton, where 77,000 people live, is the latest city bracing for impact, amid warnings of 30ft (9m) floodwaters.
More than 20 other towns have already been left cut off or flooded across an area larger than France and Germany.
The crisis has been triggered by Australia's wettest spring on record. At least six river systems across Queensland have broken their banks. The floods have affected about 200,000 people, and many have been evacuated.
"We're still directly battling floodwaters, we haven't seen the peak of the flood yet at centres like Rockhampton," said Prime Minister Julia Gillard, who toured the stricken areas.
There are concerns that damage could cost billions of Australian dollars to repair.
Mr Fraser has had to delay a fiscal and economic review in order to account for the costs of the floods.
"In many ways, it is a disaster of biblical proportions," he told journalists in the flood-hit town of Bundaberg.
"The cost to the state will be huge - both in direct costs such as rebuilding roads, and other damaged infrastructure and providing relief payments to families - but also in lost income, while the mining, agriculture and tourism sectors recover," he said.
"Royalty forecasts are likely to be hit with freight lines cut and reports that many mines may not reach full production again for two to three months."
In some areas the waters have been receding, but around Rockhampton they are still rising.
Rockhampton Mayor Brad Carter said about 40% of the city could be affected when the Fitzroy River reaches its expected peak next week.
"We know we have prepared as best we can - most people who are expecting water to inundate their houses have evacuated," he said.
He said others who needed to evacuate would be advised to leave their homes, and those who refused could be forced to leave.
The town's airport was closed to commercial flights, and Mr Carter said the area was likely to be cut off for 10 days.
"The community is still expecting to have significant amounts of flood waters at the height of about 8.5m into the middle of January," he said.
Among the areas already hit by the flooding are Emerald - a town of some 11,000 people - and two smaller towns, Theodore and Condamine, which have been completely evacuated.
In some areas, helicopters were used to deliver supplies and food to cut-off householders.
Queen Elizabeth II has sent her "sincere sympathies" to people caught up in the flooding.