Flood deaths in Australia: how do they happen and what should we do?

In March, three Australians drowned in floods ─ one on Cape York Peninsula, one on the NSW north coast and one in Sydney. This was not a month of unusually widespread or severe flooding in Australia, but it highlighted the most common cause of flood deaths. All three victims had made their way into floodwaters.

Since late 2010 there have been more than 60 flood deaths in Queensland, NSW and Victoria. Two thirds of them occurred when people drove or walked into floodwaters. The others were the result, in effect, of floods invading the human domain, including houses in towns and villages.

Broadly, there are two broad 'styles' of flood death. One was demonstrated in Queensland during the flood-rich summer of 2010-11, when 11 separate flood events each saw the death of a person who had driven into floodwaters. Some of these floods were relatively small.

The other style sees deaths in large numbers when floodwaters enter and even wash away dwellings. This happened in the Lockyer Valley in 2011 in the first flood in Australia since the 1950s to cause more than 20 deaths. Generally, big death tolls are rare and they occur only in big floods.

Entering floods is an Australian habit. People do it all the time. Every significant flood sees images on television of people walking and playing in floodwaters or driving through them. And photographs of men drinking unconcernedly, knee-deep in water in pubs, have adorned many newspapers over the decades.

These behaviours seem innocent enough, and usually they are. But not everyone gets away with them - especially with driving into floods. Some die, and others have to be rescued from floodwaters by bystanders or emergency service members. The number of flood rescues conducted in recent times is not known, but it runs into several hundreds in Queensland, NSW and Victoria since 2010. Whatever the precise number, it is not trivial.

Sometimes, the behaviour of drivers is comically ridiculous. Early in 2012 in the inner-Sydney suburb of Zetland, the occupants of six vehicles - six! - had to be rescued as, lemming-like, they made their way one after the other into waist-deep water. Each vehicle lost traction, but a State Emergency Service volunteer who was on hand in his normal employment got their occupants to safety one by one.

A painless, costless detour of a few hundred metres would have saved the cars. But people seem to be wired not to take the simple, riskless alternative if it incorporates the slightest element of inconvenience. We fail to recognise risk, or take risks that are out of proportion to our goals. In 2011, one Queenslander died while driving through floodwaters to get his daily paper.

Some of the many who have had to be rescued from floodwaters over the past few years would certainly have died had rescue-trained people not been on hand. In Newcastle in 2007, fire brigades personnel rescued dozens of people from a flash flood that had trapped them in their cars. Desperate to get home, they had taken on floodwaters that were deeper than they realised.

What do these behaviours mean? More than anything, they reflect our lack of respect for flooding. We miss the fact that floods are dangerous. We feel differently about bush fires and are much more fearful of flames than of floodwaters.

Floods kill only a handful of Australians in the average year - recent years have been worse than average in this regard - and the numbers who die are small by comparison with those lost to, say, road crashes (more than 1000 per annum) or smoking (more than 10,000 annually). But floods occur on only a minority of rivers at any one time and usually for only short periods. Road accidents and smoking are always 'available' as causes of death, whereas flood deaths can occur only in certain places and for a minority of the days in a year.

If we could standardise for the availability of these causes of death, floods would seem more significant than they currently do. If all the nation's rivers were in severe flood for an entire year and people behaved as they now do, the toll would probably be in the hundreds or even thousands.

Floods would appear even more deadly than they were in the nineteenth century, before the days of flood mitigation, flood warning and the removal of dwellings from the most hazardous parts of floodplains. In those days flooding killed more Australians than any other agents of natural disaster apart from heatwaves and epidemics. They were much more deadly than bush fires.

Of course, people's behaviour would be different if floods were more frequent and severe than they are. The dangers would be 'advertised' more clearly, respect for flooding would be higher and behaviour would be more defensive.

What should be done to reduce the toll? First, we should ram home the dangers of entering or being caught in floodwaters. The 'If it's flooded, forget it' radio, television, billboard and website campaign against driving through floods is a start, though its images have been tame by comparison with other public safety 'advertisements' like those about smoking and speeding. They have certainly not matched the Grim Reaper ads of the late 1980s which sought to frighten people into adopting safe sex practices.

But we should go further than such exhortations, anyway. Perhaps we should routinely charge people for the costs of their rescue from floods if their behaviour can be said to have been reckless, as has been done in some states of the USA. Equally we could prosecute those who remove flood barriers, in effect 'opening' roads and encouraging others to drive into floodwater.

In 2012 a Queensland man was found guilty of manslaughter and jailed for driving into a flood. His action had caused a passenger's death. Three other Queenslanders were charged with public nuisance offences for behaving recklessly in floods during the summer of 2010-11, and there have been further such cases since.

These cases attracted little public attention, and they have not featured in educational initiatives related to flooding. Neither was much made of the prominent federal coalition politician who reportedly drove his government-issued 4WD into floodwaters in northern NSW in 2011 - and wrote it off. Amazingly, he was quoted in the media complaining that there were no flood signs to warn him!

Insurance companies could play their part by voiding the insurance on vehicles damaged or written off in floods when reckless behaviour can be demonstrated.

As for big floods which have the power to kill many, the best approach is evacuation to high ground before the water arrives. Sadly, many refuse to go when advised by the emergency services or, as in the Lockyer Valley in 2011, there is no real comprehension that a potentially deadly flood is coming.

There is much complacency about the risks which floods impose. The dangers are greater than most people believe. Floods are not seen as risky - which makes them all the more so.