Queensland Premier Anna Bligh has announced a Commission of Inquiry into the Australian state's devastating floods.
Ms Bligh confirmed the death toll has risen to 20 on Monday, with at least 10 people are still missing.
The investigation will have an initial budget of $A15 million and will look at a number of issues, the ABC reports.
A Supreme Court judge, a former police commissioner and a dam expert will conduct the year-long inquiry into the floods. An interim report will be produced in August before the next wet season.
Ms Bligh says they will travel the state and hold hearings into various issues, including community preparedness and the emergency response.
"We need to learn the lessons so that we can protect ourselves better in the future."
The premier says the inquiry will answer important questions about warnings and forecasts for the badly-hit Lockyer Valley and the operation of the Wivenhoe Dam.
It will also investigate land use in flood-prone areas and how insurers have dealt with claims.
Meanwhile, the community of Condamine has suffered its second major flood in a fortnight. The Condamine River peaked at 14.8 metres on Sunday night, inundating more than 20 homes and businesses.
Some 150 townspeople were evacuated last week, just days after returning in the wake of the first flood.
Police say floodwaters are slowly subsiding on Monday but residents will not be able to return home to begin clean-up efforts until Wednesday.
Navy to patrol Brisbane waters
Defence Minister Stephen Smith is sending in the Navy to ensure that the Brisbane River is free of debris and able to flow.
The HMAS Huon will patrol waters around Moreton Bay and arrives in the city on Monday night.
Premier Anna Bligh says the state government will consider building levees and re-zoning land along the river to help protect residents from flooding in the future.
The port of Brisbane was resuming limited services on Monday and many businesses the city have opened their doors again.
Record river levels in Victoria
Some rivers in Victoria are at their highest recorded levels as floodwaters swamp towns and force homes to be evacuated.
Some 46 communities have been hit with flooding and the State Emergency Service (SES) warns a further 20 could be affected.
Some 3500 people have already fled their homes. Rochester and Charlton have been the hardest hit so far, the ABC reports.
The SES says an unprecedented amount of water is flowing down the Loddon, Avoca and Wimmera rivers, threatening communities that have not previously faced flooding.
Hundreds have already evacuated from Horsham, where the SES is describing the mass of water descending on the central-western town as a 1-in-200-year flood event.
The record flow was expected to reach the town on Monday, but emergency authorities now say the flooding is more likely to be at its worst on Tuesday.
Residents in low-lying areas near the Wimmera River have been told to safeguard their homes as the water is forecast to rival the record 1909 flood.
Floodwaters are threatening more than 500 properties in the town of about 14,000 people. Thousands of sandbags have been distributed to residents.
Elsewhere, the townships of Wycheproof and Kerang are under threat as the Loddon and Avoca rivers continue to rise.
Victoria Premier Ted Baillieu said the floods would cost the state's economy tens of millions of dollars.
Australian Prime Minister Julia Gillard visited the state on Monday.