Queensland Premier Anna Bligh has launched a royal commission into the state's devastating and deadly floods.
The $15 million inquiry, to be headed by Justice Cate Holmes, will examine the disaster, government preparedness and the emergency response.
Bligh said the operation of dams, including the adequacy of water releases from Wivenhoe, would be among issues investigated.
Bligh announced the commission of inquiry this afternoon after confirming the death toll from the floods had risen to 20, with another body discovered at Grantham.
A death in a vehicle in Ipswich last week had also been deemed flood related. More than 10 people were still missing.
Bligh said she expected the inquiry team to visit the towns and cities inundated by the floods so that local people could attend hearings and give evidence.
The independent inquiry would have the power to summon witnesses, require documents to be produced, and issue search warrants, she said.
Bligh said she would be prepared to attend the inquiry if called to give evidence and the public should be confident the government was "not going to sweep anything under the carpet".
The terms of reference require the inquiry to examine the adequacy of forecasts and early warning systems, particularly regarding the flooding in Toowoomba and the Lockyer and Brisbane valleys.
The preparation and planning by federal, state and local governments and emergency services will also come under the spotlight.
Bligh said the disaster needed to be examined thoroughly.
"The last three weeks have been truly shocking for all Queenslanders and now is the time to forensically examine the devastating chain of events and the aftermath," Bligh said.
The head of the new inquiry, Justice Holmes, is a sitting Supreme Court judge and was counsel assisting the Forde Royal Commission into child abuse in 1998.
The initial budget for the inquiry would be $15 million, Ms Bligh said.
"I know that sounds like a lot of money but this is an investment in our future safety," she said.
An interim report on flood preparedness issues is due by August 1 this year so they can be implemented before next summer's wet season.
The final report is due by January 17 next year.
FACES OF THE LOST
Meanwhile, police have released a list of dead and missing in Queensland's flood disaster, giving details of how they died or when some were last seen.
It comes as record floods were predicted in several rural Australian communities today as rivers swollen from upstream rain flowed heavily into southern states.
The focus of today's concerns however has switched to Victoria in southern Australia where officials expected floodwaters to drown out highways and isolate dozens of towns in northeastern parts of the state.
The town of Horsham could face a major flood during today's expected peak of the Wimmera River. Up to 500 properties in the town of about 14,000 people could be affected.
With a massive search still under way in the Lockyer Valley, the families of those missing agreed to release the names and photographs of their loved ones in an attempt to help find them.
They include Regina Vanderwerf, 82 - who was last seen inside a Grantham house but was unable to reach other family members who escaped the deluge - and Dawn Margaret Radke, 56, who went missing along with her toddler granddaughter Jessica Keep, when a torrent of water smashed through a brick wall of their Grantham home and carried them away. Another family member sheltering in the house, Pauline Magner, 65, was yesterday confirmed dead, but four others survived.
Police have dealt with 200 missing persons reports since floodwater rushed down from Toowoomba and through the Lockyer Valley on Monday, but that number has been revised down to 14, with grave fears held for all of them.
All of those missing and many of the dead are from the valley, which bore the brunt of the flooding, described by some survivors as like an "inland tsunami".
Six of those known to have died came from Grantham, with the search now focused downstream of the town, 100 kilometres west of Brisbane.
The only victim police had previously identified was Donna Rice, 43, who died along with her son Jordan, 13, after being trapped inside their car in the Toowoomba CBD on Monday.
Police yesterday named six more victims known to be dead including mother Llync-Chiann Clarke, 31.
Ms Clarke, her 12-year-old son Garry Maguire and five-year-old daughter Jocelyn Maguire perished when they became trapped inside a rural fire brigade truck that was flooded while on Gatton-Heildon Road, in Gatton.
Other victims named yesterday were: Robert John Kelly, 30, whose body was found on Wednesday in a grey Toyota LandCruiser that was upside down in Myall Creek, Dalby; Van Toan Giang, 24, who disappeared under water while trying to check his family's property in Durack; Jean Gurr, 88, who was trapped inside her home when the wall of water hit and was later found dead inside; and Selwyn Schefe, 52, whose body was found after he was swept away from the tray of a ute as his house collapsed. Mr Schefe's daughter Katie, 6, is still missing, but his wife, Catherine, 50, survived after grabbing hold of a tree.
Three of the official dead are yet to be formally identified, including a man and a woman who were found in separate locations in Grantham. Police are also investigating two reports of women swept away in Toowoomba and Grantham.
'WE ARE NOT OUT OF THE WOODS YET'
A total of 43 Victorian towns have now been flooded, affecting more than 1400 properties and more than 3500 people, with 5200 calls for assistance received by emergency services.
As the big rivers flow down into creeks and streams, many smaller townships are bracing themselves: '... There will be vast tracts of land that look like inland lakes.''
Four major rivers in flood have affected about a quarter of the state.
There are predictions Victoria's flood crisis will continue for days, with water levels in Horsham and Echuca due to peak today and tomorrow and many small towns expected to face inundation as creeks and streams swell with water moving downstream.
''The message to Victorians is that we are not out of the woods yet as far as this flood crisis is concerned,'' said Trevor White, state controller for the State Emergency Service (SES). ''In some of our river systems we are seeing unprecedented stream rises.''
An emergency evacuation alert was issued to Echuca yesterday as the Campaspe River continued to rise beyond predictions.
Last night 170 people were evacuated and 170 properties were flooded.
Mr White said large areas would be flooded: ''We anticipate parts of the central business district and areas to the west of the Campaspe River in Echuca to be impacted,'' he said.
Communities cut off by floods will be receiving airlifts of food and fresh water supplies.
Charlton, where besieged residents are enduring their second big flood in four months, was the first recipient.
''It's shocking, devastating, terrible, heart-wrenching,'' said local businessman Peter Gretgrix, of the wreckage of the main street. ''It's just total devastation. Some of the shops in the lowish area are just a mess, windows smashed out. I've never seen anything like it.''
More than 6500 properties were without power yesterday in towns including Charlton, Donald, Birchip, St Arnaud, Boort and Wycheproof. Powercor worked to restore electricity during the day.
A total of 18 emergency centres around the state have given refuge to up to 600 people at a time, but only 11 were in use yesterday, a spokeswoman for the Department of Human Services said.
Snakes have been reported in floodwater in some areas, and health authorities have warned people to beware of obstacles in water.
Electricians warned that appliances that had been flooded should not be used until they were professionally tested.
Deputy Commissioner of Police Kieran Walshe again urged people not to walk, ride or drive into floodwaters, with 50 rescues now having been performed, 30 of them relating to people in cars.
Mr White said the floods were ''dynamic'' and urged residents to be vigilant and to continue to monitor emergency broadcasters, the SES website, or the information line 1300VICSES.
- with Sydney Morning Herald, AAP, The Age and Brisbane Times