Were the Queensland floods preventable

Answer 1

There have been many floods in Queensland in recent years, and whether or not they have been preventable has differed with the circumstances.

To some degree, floods are always preventable, but at the same time, it is almost impossible to foresee the effects of erratic weather patterns on any one area. There are standard plans and preparations that should always be made: keeping drainage pipes clear, having levee banks and emergency embankments ready, evacuation plans, etc. But there is no way to predict what weather patterns will actually do.

For example, in the late 1980s, the outback town of Charleville was inundated by floods which ravaged the town, and made it impossible for homeowners to be eligible for flood insurance. In January 2008, much of Queensland was under water as a result of extremely heavy rainfall further north in the Warrego River catchment and feeder rivers. The Charleville Flood Barrier Response swept into action and prepared the town for flooding, with levee banks and a temporary flood barrier. The town was saved, and as a result, some insurers lifted their bans on flood insurance for Charleville.

Meanwhile, those same conditions devastated Mackay, on the central Queensland coast. Mackay had been hit by floods before, and had action plans to reduce the impact - but in this case, they were of no avail. The rain that drenched the city was the worst in 20 years, and quite unexpected. If the Mackay city council had taken action ahead of time to counter such devastating floods, many people would have questioned why so much money was being spent on flood mitigation plans.

Brisbane's floods of 1974 were the result of another unusual situation. Whilst the depression which dumped hundreds of millimetres of rain as a result of Cyclone Wanda was unprecedented, it was made more catastrophic by the fact that it had already been a very wet year beforehand. And who could have foreseen that a huge container ship would break loose from the shipyards, and wedge itself across the Brisbane River just before the mouth, preventing the escape of the water to the sea?

Currently (2010-2011) Queensland is in the grip of devastating floods right across the state. Wivenhoe Dam, the huge dam that was built to help prevent a recurrence of the 1974 Brisbane floods, hit over 190% capacity. The dam was Brisbane's best defence, but even that was not enough. The combination of a La Ninaweather pattern, together with a widespread cyclone system that hit north Queensland on Christmas Day, meant that unusual amounts of rain fell, and continued to fall across an already waterlogged state. In this case, there is just no way to prevent the floods. No-one could have foreseen the wall of water that rushed through Toowoomba, which sits right at the top of the Great Dividing Range, and devastated the communities at the base of the range, then filled Wivenhoe Dam to over its capacity. On the other hand, the issue of controlled releases from Wivenhoe Dam prior to the catastrophic events of January 10 are the subject of a Commission of Inquiry.

There is no black and white answer to the question "Were the Queensland floods preventable?" Councils and Emergency services can do the best they can, but when one faces a once-in-50-years situation, there really is nothing anyone can do.