More than 50 Brisbane suburbs will be hit by flooding as the Brisbane River gets to 4.5 metres on Wednesday afternoon before surging towards its expected peak of 5.5 metres on Thursday - the worst flooding the city has seen in more than a century.
About 19,700 properties are expected to be flooded, with 3500 commercial blocks also affected.
Around 6500 people are expected to take up shelter at emergency centres.
The Bremer River which flows through the city of Ipswich is set to peak at about 20.5 metres before noon (AEST) on Wednesday - just below the catastrophic 1974 20.7-metre peak, Ms Bligh said.
Up to 4000 homes will be inundated at the peak and already about 1500 Ipswich residents have taken up emergency shelter.
Fifteen Australian Defence Force helicopters as well as other aircraft and vehicles are assisting police and emergency service officials in responding to thousands of calls for help and searching for missing people.
Ms Bligh warned local residents to stay off roads if possible.
"This incident is not a tourist event - this is a deeply serious natural disaster," she said.
"Stay in your homes - do not travel unless it is absolutely necessary."
The premier urged those on higher ground to take in neighbours and friends affected by flooding, warning it could last several days.
"I think we've still got our hardest times ahead of us," she said.
Bligh says a major search and rescue effort will be launched to find 90 missing people in the Lockyer Valley as the state braces for further flooding.
The premier, flanked by Prime Minister Julia Gillard, described it as the "worst natural disaster in our history".
Ms Bligh said the number of dead remained at 10, with more than 90 people still missing in the Lockyer Valley west of Brisbane, where flash flooding had caught many families by surprise.
Call the SES in Queensland on 132 500
Follow us on:
