After seven weeks of hearings, a Commission of Inquiry into the floods last summer in Queensland will deliver its interim report on Monday on what went wrong.
The disaster affected 70% of the state. Parts of Brisbane CBD and many suburbs along the river were inundated in January.
Thousands of properties were flooded in Ipswich, west of Brisbane.
The commission has examined the management of Wivenhoe Dam, west of Brisbane, the preparedness of councils and their response after the flooding and cyclones has been examined.
The report will consider the chain of events leading to the floods, how dam flows were managed, and how well authorities responded to the tragedy that followed, especially in the Lockyer Valley.
Premier Anna Bligh says the State Government wants to make sure that the lessons of 2011 are learned.
''I don't care if it's tough, I want answers.'' she said. ''We need to make sure we're as ready as we can be for any future events.''
The commission's final report is due in February after more hearings later this year.
The floods covered an area larger than the size of France and Germany. More than 80 towns were affected. The floods were followed by Cyclone Yasi in February.
