Engineer bores a hole in dam untruths

WIVENHOE Dam is increasingly seen as the chief culprit behind the Brisbane flood.

MICHAEL O'Brien is the stereotype of a cautious engineer. Determined to be methodical and accurate, he is painstakingly focused on facts: numbers, charts, mathematical calculations, operating procedures and ratings curves.

These elements, O'Brien says, should inform the true story of what he describes as Brisbane's great avoidable flood of January 2011. He has not been distracted by the soft treatment of contrary and uninformed opinions published widely in the media. O'Brien has no doubt about the validity of his findings because they are derived from mathematical and scientific analysis of the available facts.

Before the disaster in southeast Queensland, he had not shared information with journalists or reached out to the media. He does not seek public attention.

His contact with The Australian from January 15 began because he was concerned that with a traumatised community in shock, the official version of events -- that the massive Wivenhoe Dam had "done its job" and prevented a much worse flood from engulfing Brisbane -- would align with public perceptions and become accepted as fact.

O'Brien, 61, a senior manager of an ASX-listed resources company, has no financial, political or professional motive for having spent most of his spare time in the past two months on exhaustive research into the floods.

As a proud born-and-bred resident of Brisbane, he was initially troubled about why the flood event in Brisbane had escalated so suddenly into a near catastrophe. He was distressed at the impact of the floods: the destruction of thousands of homes and businesses, most awaiting rebuilding; the crushed confidence of residents; a multibillion-dollar damages bill; the most expensive disaster in Queensland's history.

Analysis of flood events is not new to him. As a chemical engineer with large firms from WorleyParsons to Evans Deakin Industries to Santos, he has managed big projects. Interpreting and relying on rainfall and flood mapping for the protection of infrastructure and plant is part of his job.

O'Brien had suspected the unthinkable when the Brisbane River was peaking at 4.46m in the pre-dawn on Thursday, January 13. Having closely followed the dam's operation, he suspected then that the dam had almost certainly not done its job and its releases of huge volumes of water in fact caused the major flood.

The just-completed product of O'Brien's research, a detailed document titled Brisbane Flooding January 2011: An Avoidable Disaster, will be a shock to many. In analysing the evidence and providing his final report to Inquirer (it is available on The Australian's website) and to the public inquiry into the floods, O'Brien says he is not seeking to apportion blame. But he is determined to ensure lessons are heeded.

For those who have not analysed the timings and impact of the releases from the dam, who have not questioned why the dam was permitted to become so full that its operators suddenly ran out of options on Tuesday, January 11 -- and who remain insistent that a lot of rain, not human error, caused one of Australia's worst disasters -- O'Brien's analysis and conclusions will be sobering reading.

Since he first went on the record in mid-January with calculations showing that a significant cause of the flooding in Brisbane was directly due to the operation of the dam, he has watched with detached bemusement as outspoken bloggers, journalists, spin doctors and commentators, and even former hydrologists, none of whom had themselves done the calculations, tried to argue the opposite.

"A lot of the commentary was very lightweight," O'Brien says.

But now a flow of findings by experts and engineers with no connection to O'Brien confirms his position. During the past 10 days the expert studies and complex hydrology have been consistent: massive releases of water from Wivenhoe Dam on Tuesday, January 11, did indeed produce most of the flooding in the Brisbane River the following afternoon, with a peak in the early hours of Thursday morning, January 13. Even the dam operator, SEQWater, which insists it performed well, concedes as much in a carefully qualified part of its 1180-page report.

The dam's releases into the Brisbane River also caused the Bremer River, which winds through the city of Ipswich, and the Lockyer Creek to back up and cause much of the flooding outside Brisbane.

The studies are based on comprehensive scientific modelling of the facts. The overwhelming picture is increasingly problematic for the Queensland government and SEQWater.

Hydrology experts not directly associated with SEQWater conclude that the official categorisation of the January disaster is "dam release flood".

They say of the five separate physical phenomena that can cause flooding, dam release floods "are caused by the rapid release of large volumes of water from a dam, typically as an emergency response to an incoming flood. If sufficiently large, the release can overtop the banks of receiving waterways and inundate downstream communities."

A panel of hydrologists and engineers from WorleyParsons, WRM Water and Environment and Water Matters International, in a newly released report for the Insurance Council of Australia, states: "Releases from Wivenhoe Dam caused a floodwave in the Brisbane River -- dam release flooding.

"As this floodwave moved downstream, backwater flooding occurred along the lower reaches of Lockyer Creek and the Bremer River, and along the lower reaches of all other tributaries further downstream. The principal cause of flooding along the lower Brisbane River downstream of Wivenhoe Dam was releases from the dam, especially over the period [from 6am, Tuesday, January 11, until 3am the following day].

"Lockyer Creek and the Bremer River were still delivering, or attempting to deliver, floodwaters to the Brisbane River when backwater flooding occurred along these waterways. Thus, a 'dam release flood' from Wivenhoe Dam was the principal cause of flooding along the mainstream and tributaries downstream of the dam."

The panel concludes that the releases from Wivenhoe "dwarfed" the natural flooding in the lower Brisbane River, Bremer River and Lockyer Creek, significantly increasing the water levels.

Although the panel's experts do not attempt to answer what they describe as "pertinent questions in relation to the performance of Wivenhoe Dam", they ask: "Were releases from the dam unnecessarily high? Or did releases reflect prudent operations of the dam during the passage of a major flood event? Would a different pattern of releases have reduced downstream flooding to a significant extent? Or was the volume of the water in the flood so great as to eliminate options for effective mitigation?"

These are critical questions. O'Brien, who answers them in detail in his report to the commission of inquiry, is in no doubt that the releases were unnecessarily high because the dam was not operated prudently, and that a prudent operation would have prevented most of the flooding.

The increasing evidence is inconvenient for those who have mostly downplayed, ignored or criticised the proposition that poor management of the dam flooded Brisbane.

For publishing thousands of words based on the early analysis of O'Brien and other independent engineers, some of whom requested anonymity, The Australian has been taken to task by critics who neither unpacked the data nor asked independent engineers to model the facts.

Neal Ashkanasy, who specialises in social and organisational psychology (and 35 years ago was involved in the design of Wivenhoe Dam), was repeatedly interviewed to hose down claims the dam was operated poorly.

Ashkanasy's view is that the dam was run with outstanding precision; the problem now, he says, is that since the flood people have a "desperate need to find someone to blame. Human beings do that. Psychologists call it the fundamental attribution error." He told The Sydney Morning Herald: "We're also seeing that people are unable to differentiate emotions from logic, and that always happens after an event like this."

O'Brien remains concerned that despite the abundance of evidence now available and the conclusions being made by the experts, a lack of rigour exposed in much of the media's treatment of the disaster will lead to the dam's performance being given the benefit of the doubt. His primary objective is that while the hard lessons from this disaster might damage reputations, the lessons must be learned.

"I am a Brisbane boy and in the 25 years since Wivenhoe Dam was built, I really did believe it would protect people from the next big flood," O'Brien tells Inquirer.

"A dam like Wivenhoe is potentially extremely dangerous. I would have to say that I do not have any confidence now in the management of the dam. I do not have any confidence that they will not flood Brisbane again.

"They banked water in the dam for far too long during a flood event and then, at the worst possible time on the Tuesday [January 11], they panicked and released so much water that they not only flooded Brisbane but also backed up the Bremer River through Ipswich and the Lockyer Creek, which made the flooding in those areas worse and longer-lasting. They had multiple chances to ensure Brisbane would have had a minor flood instead of thousands of properties flooding.

"I think the operators of the dam know exactly what happened . . . Their log entries indicate the engineers on duty knew they had to change strategy late on the Sunday [January 9], but something happened -- they didn't adopt their own recommended strategy, which would have prevented the major flood, until they faced a crisis on Tuesday and had to make huge releases. The guys were reporting on Sunday to more senior people. What happened at that point? Why did the strategy that was recommended change? It is a very important question."

In his report, O'Brien notes that the flooding in Brisbane could have, and should have, been substantially avoided and that "some 50 to 60 per cent of the water passing the Brisbane City Gauge during the major, moderate and minor flooding was water released from Wivenhoe".

He states: "SEQWater was slow to react through the whole period examined. The delay in responding, especially in the days leading up to Monday, January 10, eventually left SEQWater with few alternatives."

O'Brien also highlights an intriguing failure of the Wivenhoe Dam and its smaller cousin, the Somerset Dam, to store water at their claimed capacity for flood storage (not including the capacity for urban supply) of a combined 1,974,000 megalitres.

During the whole of the flood event, he notes, "the maximum combined storage in the flood compartments of both dams was only approximately 1,373,000ML". The difference means about 690,000ML of flood storage capacity "was not used or was unavailable during the critical period". These numbers are highly significant when compared with the 623,000ML that is the estimated reduction in releases that would have been required so that even minor flooding did not occur in Brisbane."

In the hours before the river peaked, Premier Anna Bligh and Lord Mayor Campbell Newman praised the operation of the Wivenhoe Dam and, ashen-faced, issued dire warnings of a flood then on its way from the dam. Whether they will still be praising the dam in the coming months of inquiry remains to be seen.