Queensland on Tuesday declared a flood disaster over an area the size of France and Germany after recent storms.
Thirty Queensland communities covering 969,000 square kilometres were declared disaster zones by Emergency Services Minister Neil Roberts, including many outback and rural communities.
Two communities are expected to be isolated for at least another six weeks.
Queensland residents affected by storms would be able to apply for government assistance payments if they were "unable to recover via their own means", Mr Roberts said.
Eight big rivers remain in flood after heavy rains and a cyclone moved across the state, cutting roads and forcing many small communities to rely on air drops of food and fresh water.
Flooding is expected eventually to extend inland, helping fill lakes and relieving a long-running drought in parts of Australia's desert interior and tropical north.
The damage bill is estimated at more than $NZ73 million.
In New South Wales, meanwhile, firefighters are battling several small blazes that are being fuelled by hot temperatures.
