Wivenhoe Dam in sights of flood inquiry

PREMIER Anna Bligh yesterday bowed to pressure to set up an inquiry with the powers of a royal commission, as the death toll from the flooding hit 20.

PREMIER Anna Bligh yesterday bowed to pressure to set up an inquiry with the powers of a royal commission, as the death toll from the flooding hit 20.

Fresh claims that 80 per cent of the Brisbane River flood, at its peak, was a direct result of the forced release of a huge volume of water from the city's main dam will be investigated by the judicial inquiry into the disaster in southeast Queensland.

The federal government has also refused to rule out any options for funding the multi-billion-dollar cost of reconstruction, including a national levy.

To be headed by veteran judge Cate Holmes, the inquiry will investigate whether enough was done to prevent the loss of life and massive property damage in Brisbane and communities to its west.

Central to the inquiry will be questions, raised by The Australian, of whether Wivenhoe Dam was mismanaged in the lead-up to the emergency that erupted last week with deadly flash flooding in Toowoomba and the Lockyer Valley, and led to the worst flooding on record in Brisbane and neighbouring Ipswich.

More than 80 per cent of the flood in the Brisbane River at its peak last Thursday was the direct result of the release from Wivenhoe, the city's flood shield, of up to 30 per cent of its capacity, according to official data obtained by The Australian. The data shows that, without the unprecedented and massive release at a peak rate of 645,000 megalitres a day from the dam on Tuesday, January 11, the flooding in Brisbane would have been minimal.

The inquiry's terms of reference, released yesterday by Ms Bligh, call for scrutiny of the water release strategy for Wivenhoe and Somerset Dam further upriver, and their suitability for "flood mitigation and dam safety".

Data from Wivenhoe's registered owner and operator, the Queensland government-owned SEQWater, shows that the peak flow in the Brisbane River in the early hours of the flood last Thursday was about 9000 cubic metres per second. It takes about 36 hours for a release from the dam to reach the city gauge in Brisbane.

Hydrology and engineering experts said a release of a peak rate of 645,000 megalitres a day would produce a flow of almost 7500 cubic metres per second, although a number of factors, including river contours and the time it takes water to travel from the dam to the city gauge in Brisbane, mean the extrapolation is not precise.

However, they said it was clear that the flooding occurred because of the release from the dam.

The flooding Bremer River, which cuts through Ipswich and meets the Brisbane River to the west of the state's capital, was not nearly enough on its own to cause the devastating flooding of thousands of homes in Brisbane.

One of the most critical tasks for the commission will be to examine whether the operators at Wivenhoe Dam retained water in the dam's flood compartment for too long, forcing a drastic release that compounded the flood instead of mitigating it.

The commission of inquiry will also pore over the emergency response and the performance of private insurers after the flooding, and hand down interim findings on flood preparedness in August.

Mr Bligh has ordered Justice Holmes to deliver her final report by January 17 next year. If her government runs full term, as the Premier has promised, this will be in the lead-up to the state election, due by March next year.

In interviews yesterday, Ms Bligh stopped short of commending the operation of Wivenhoe ahead of the Brisbane flooding that inundated more than 17,000 homes and 65 suburbs, the CBD and central parts of Ipswich.

"I want to know that our dams work as they're supposed to and are operated as well as they technically can be," Ms Bligh said.

"I want to reassure the people of Brisbane that I want - just as much as they do - to know the answer to these questions. And I think they are very technical questions and that we need to get expertise from around Australia to really have a look at what happened, what could have been done differently so that we are well prepared should we ever see that sort of water coming into that catchment again. So these are very legitimate questions and I'm not going to shy away from them. I want to know the answers just as much as anybody else."

The development came as The Australian established that a flood levee was one option before the federal government as it grappled with funding the lion's share of the estimated $10bn-$20bn cost of rebuilding after the floods.

Last night, after Ms Bligh confirmed the 20th death of the southeast Queensland emergency, with another 12 people listed as missing, the Victorian town of Horsham, 300km northwest of Melbourne, was being evacuated ahead of a "once-in-200-year flood".

A federal levy to fund rebuilding could be modelled on surcharges imposed by the Howard government to pay for the gun buyback following the 1996 Port Arthur massacres and payouts to sacked Ansett staff after the collapse of the airline in 2001.

It would likely take the form of an addition to the 1.5 per cent Medicare levy, which currently raises about $10bn a year.

Julia Gillard indicated yesterday that the government's obligations to support Queensland would form part of the planning for the 2011-12 budget.

"There's going to be a lot of effort and money and resources needed to rebuild, particularly rebuild Queensland, but we'll be managing the federal budget . . . so that we can meet those needs as well as managing the budget into surplus in 2012-13," the Prime Minister said. Wayne Swan said yesterday the government was not yet ready to announce the form of commonwealth assistance but he confirmed it would be a significant burden on the budget.

A levy would likely be confined to paying for the rebuilding of infrastructure damaged in the flood, not assisting householders whose insurance policies had proven inadequate. The damage bill of up to $20bn is set to rise as emergencies continue to unfold across southern Queensland, in Victoria, and also in NSW, where flooding has hit the state's north and central districts. South Australia, northern Tasmania and the Carnarvon region of Western Australia have also been hit by flooding.

Announcing the inquiry, Ms Bligh said Justice Holmes had been empowered to comb over all aspects of the preparation and planning for the floods. "This commission of inquiry . . . is absolutely critical to us understanding firstly the community preparedness and the emergency response," she said. "We need to learn the lessons of this event so that we can protect ourselves better in the future. We need to honour those who have tragically lost their lives in this catastrophe and we need to do that by learning the lessons of the event."

Justice Holmes, a Supreme Court and Appeals Court judge of 10 years experience, who once represented mass killer Ivan Milat in private law practice, will be assisted by post-Fitzgerald inquiry Queensland police commissioner Jim O'Sullivan, and Phil Cummins, the chair of the international council on large dams.

The Australian yesterday revealed expert concerns that water releases held back in the week prior to the Toowoomba and Lockyer Valley deluge kept Wivenhoe Dam at dangerously high levels and worsened flooding in Brisbane. "In the aftermath of this event, people have legitimate questions and those questions, in my view, require a comprehensive and rigorous examination of all of the factors surrounding these events," Ms Bligh said. "In relation to the Wivenhoe Dam, it is legitimate to ask questions about the operation of that dam. Like so many other people in this city, I live here with my family, I have the same questions and want to make sure that we are getting absolutely thoroughly tested information in answering that question."

She said the assessment would also investigate whether other dams in the region could help mitigate floods in the future.

The Local Government Association of Queensland raised concerns last week that an inquiry could divert essential resources from the clean-up effort, but Ms Bligh said she had requested the commission to structure the hearings to allow vital work for small and medium councils to continue unimpeded.

Additional reporting: Rosanne Barrett