Cleanup crews toiled under more pounding rains Thursday to clear mountains of debris in flood-ravaged communities across northeastern Australia, and one mayor warned it could take his city up to a year to recover from the worst flooding in decades.

Officials were only beginning to see the scope of the damage as river levels across Queensland state started dropping despite new thunderstorms. Flood waters were expected to stay high in many areas for at least another week, and officials asked residents to stay far away from their waterlogged homes.

"It's important for the community to remember that this event is not over yet," said Brad Carter, mayor of the inundated city of Rockhampton, which has evacuated 500 people.

"Those residents who were required to evacuate their homes will not be able to return to their homes until the flood waters recede."

Four thousand people across Queensland have been forced from their homes since driving rains that began just before Christmas left much of the region under a sea of murky water. Around 1,200 homes have been inundated, with another 10,700 suffering some damage in the flood zone, an area larger than British Columbia.

Flooding hits farmers

The flooding has already had a major economic impact on the region, devastating crops and shutting down three-quarters of the state's lucrative coal mines. The total cost is not yet known, but Queensland Premier Anna Bligh said the price of rebuilding homes, businesses and infrastructure coupled with economic losses could be as high as $5 billion.

Farmland south of Rockhampton, Queensland, is inundated with flood water. Despite fresh rains, the overflowing Fitzroy River began to slowly recede on Thursday. (Patrick Hamilton/Associated Press)

The flooded city of Bundaberg, a major producer of sweet potatoes and peanuts, launched a task force to determine how much damage the deluge has done.

"This region supplies about a third of Australia's small crops, and we need to know what the impact is going to be on farming in the area, and what impact it's going to have on the rest of the country," Mayor Lorraine Pyefinch said. "We're responsible for feeding the country, so that's something we need to look at closely."

The good news for the nearly 200,000 flood victims is that the crisis finally appears to be easing.

Despite the fresh rains, the overflowing Fitzroy River in Rockhampton began slowly receding Thursday. It has spilled onto 3,000 properties throughout the city, leaving 200 homes with water above the floorboards.

The mayor warned the city of 75,000 was in for a long cleanup and recovery period.

"I think that this could drag on for 12 months," Carter said.

A man with an injured foot gets into his car in flooded Depot Hill in Rockhampton, Queensland, on Thursday. (Daniel Munoz/Reuters)

In the state's southwest, the 150 residents of the tiny community of Condamine had hoped to return home Thursday, a week after they were airlifted to safety when the Condamine River inundated 42 of the 60 homes.

But a storm that rolled in Wednesday afternoon shut down highways and more rain forecast through the weekend could delay their return.

The town has no electricity or running water, and schools and churches are also under water.

"The damage is extremely significant," Western Downs Regional Mayor Ray Brown said. "On the scale of devastation, on a percentage, it's a massive impact."