Why do we manage flooding so poorly?

Today is the second anniversary of the devastating flooding that took so many lives in Queensland's south-east during that state's infamous 'summer of floods'. It's an appropriate moment to ask how well we deal with flooding in terms of the safety of life and the protection of material assets. Sadly, we manage it poorly; much less well than we could - and should.

Let's put the summer of 2010-11 into perspective. Across Queensland, New South Wales and Victoria there was repeated, often severe flooding between the months of September and March and more than 40 people died. These were nearly equally split between people intentionally entering floodwaters, on foot or in vehicles, and floodwaters invading the human domain as occurred in the Lockyer Valley where houses were washed away with people inside or on top of them. The 22 deaths of 10-11 January in Toowoomba and the Lockyer Valley represented the most in a flood episode emanating from a single rain event since the floods of the Hunter Valley and north-western NSW in 1955.

Figures on the economic cost of flooding are notoriously rubbery, but contemporary estimates for Queensland that summer placed the damage bill at about $5-7 billion. Taking this as indicative, it follows that the total cost for the three eastern mainland states would have been of the order of $10 billion in terms of damage to and loss of private and public assets. Add in the lost production and the total cost would have been much higher.

By any measure it was a bad flood period in eastern Australia, though far from unprecedented. There were extremely bad flood years in the mid-1950s, the mid-1970s and the early 1990s as well, with deaths, dislocation and damage over large areas. Flood disaster is a recurring theme in our history. Notwithstanding a considerable reduction in deaths due to flooding over recent decades, no other natural peril has been more costly in dollar terms. Worse, the dollar cost is still rising in real terms.

Given the seriousness of the consequences of flooding and its high degree of predictability, it might be expected that we would have learned to behave defensively during floods and developed sound community coping strategies. Yet we have not. Fault lies with individuals and governments alike.

Many Australians are complacent about the dangers posed by floods. During the summer of 2010-11 a total of 15 Queenslanders were killed in 15 separate incidents because they entered floodwaters in vehicles or on foot. In one case a driver was jailed for the manslaughter of a passenger who drowned. A year later, ten people had to be rescued one after another when six cars were driven into chest-deep floodwaters in Zetland, in inner Sydney. Each car lost traction but, oblivious and lemming-like, others followed them into the water.

The internet nowadays is replete with footage of people driving through deep, fast-flowing water. They must think floodwaters are harmless, but they under-estimate the dangers.

Nor does the fault lie only with drivers. Residents are notoriously slow to react to flood warnings, often doing so only after they have seen the water rising close to their homes. Thus time to save possessions and to evacuate in relative safety is routinely lost. Here it must be said that the emergency services are not at their best in warning people of approaching danger: the task of persuading people to act before floodwaters arrive tends to be given a lower priority than resupplying those who have become isolated or evacuating those who are in imminent danger. Moreover, until recently little attention was given to educating people about minimising the harm which floods can do. Governments have been tardy in supporting educational endeavours about flooding and its dangers and much of what is done remains cheap and limited still.

Councils, too, can make flood management difficult. Not infrequently, elected people undermine State Emergency Service efforts to persuade residents to act appropriately and in a timely fashion as floods approach. Cases of mayors talking down Bureau of Meteorology flood warnings or SES advice to evacuate are legion and discourage prudent behaviour on the part of their constituents. One day, a mayor who counters SES advice will later be seen to have endangered lives and property by dissuading people from taking appropriate risk-reducing action.

Much of the problem of flooding in this country has been inherited from previous generations. Towns were sited during the nineteenth century next to rivers and creeks for reasons of water supply and ease of transport, and once they were established there was good economic reason for their citizens to seek further growth. Governments supported them by encouraging further development even in locations which were liable to flooding. They continue to do this even as our knowledge of the seriousness of the flood problem increases. In effect, governments (including councils) ensure that the flood problem is magnified and that future generations suffer even more from it.

Certainly there have been instances of community investment in flood mitigation and in efforts to re-direct urban growth. In the half century after the disastrous floods of the mid-1950s, NSW spent well over $1 billion in today's terms on managing floods. Dozens of towns were given a measure of protection, usually in the form of levees, while many flood retention basins were constructed in Sydney. The other states lagged behind in building flood-controlling structures and in buying out the most flood-prone properties, but all invested some resources in flood mitigation and discouraged development in seriously flood-liable locations.

Nevertheless, in general their efforts were piecemeal, unsystematic and poorly sustained, and even in NSW the focus on floodplain management has waned significantly of late. Attention has shifted to other matters. Meanwhile the push to develop floodplains for urban purposes has, if anything, gathered pace over the past decade. There is a contradiction here: less mitigation, more development on floodplains. A price will inevitably be paid.

The folly of governments' thinking on the matter of urban development on floodplains can be demonstrated in many areas, but two cases will make the point. In Brisbane, the great flood of 1974 saw the Bjelke-Petersen government build Wivenhoe Dam partly for the purpose of flood mitigation. The mitigation benefits were loudly trumpeted and their limitations ignored, and the impression was given that the dam would solve the problem of flooding from the Brisbane River. Further development on the floodplain within the city was greatly encouraged. The 2011 flood peaked at a lower level in Brisbane than the 1974 event had done, partly because of the increased flood storage available, yet many more dwellings and other buildings took in water. The mitigation benefits of the dam were more than countered by the increased development of the floodplain.

The other example is Maitland, in the Hunter Valley. Eleven people died there in the 1955 flood and more than a hundred houses were swept away or had to be demolished later. The state government reacted by banning residential redevelopment in and around the town's Central Business District and creating a system of levees and floodway bypasses. Many home-owners, tired of repeated flooding and alarmed by the severity of the 1955 event, trucked their houses to high ground nearby, and the processes of out-migration, demographic aging and commercial expansion saw the population of central Maitland drop to a third of its pre-1955 level by 2011. Unsurprisingly, the CBD began to suffer.

The council's response to the CBD's woes was to convince the state government to drop its decades-old opposition to residential redevelopment on the floodplain. Now, Maitland has the explicit goal of housing as many people in the area as lived there before 1955. Yet the levees are designed to keep out only floods up to the level of the 5% Annual Exceedence Probability flood â"€ the so-called once-in -20-years (on average) event. A case can be made that the intended development will restore the community's pre-1955 level of flood vulnerability. Infrastructure that will inevitably be damaged or destroyed will have to be replaced, repeatedly, and many more people will be put at risk even though the floors of their dwellings will be above the level of the estimated 1% flood. The problem of the faltering CBD will be addressed by creating an even greater problem, that is, by placing more lives and assets at risk.

There is an underlying pattern here. State and local governments are determined to achieve 'development', despite the risks that are involved, so questions about the location of that development are either not posed or are carefully circumvented in planning processes. The threat posed by flooding is deliberately minimised and the improvements in flood management that have occurred are emphasised and sometimes exaggerated. Departments of planning, both state and council, have become departments of development supporting the needs of the development industry. Protecting lives and property has become secondary.

Society regularly debates the merits of development versus environmental preservation, but rarely the impacts of development on public safety and the protection of assets. Between floods we (like our political and bureaucratic masters) become convinced that the risks of flooding are overstated, and we agonise about the problem only when flooding strikes again. Then we lose interest once more. Yet those whose dwellings or businesses are flooded can find the experience ruinous as well as distressing.

Brisbane and Maitland exemplify what is known as 'the levee paradox' in which a community, tired of flooding, pressures government for protection. When the protection is provided (for example in the form of levees, mitigation dams or other works), there is pressure to further develop the land in the protected areas. Then a flood occurs that exceeds the capacity of the mitigation devices, and the costs to the community are greater than they would otherwise have been because of the additional or intensified development. This is precisely what happened in Brisbane between 1974 and 2011, and precisely what will happen in Maitland when the levees are overtopped as they are designed to be in a flood much smaller than 1955's.

We have allowed the problem of flood vulnerability to grow - slowly but inexorably. The legacy of decades of ill-advised development has increased to the point that it is economically impossible to remove residential and other development from all but the most severely flood-prone locations. Yet we keep increasing the size of the problem in the usually lengthy periods that elapse between episodes of significant flooding in particular locations, only to be surprised when the inevitable occurs and the costs imposed are shown to have increased greatly. We also condemn ourselves to funding expensive recovery programmes which have to be mounted repeatedly (sometimes with special levies being needed) as well as to increased home and business insurance premiums. Costs are piled upon costs, and one way or another we all pay.

Yet there is no need to develop floodplains in ways that will guarantee more economic loss and put more lives at risk. Both in and around most of our towns and cities substantial tracts of land are available beyond flood reach. But we cannot grasp the in-built contradictions and inefficiencies of our approach to development.

Between individual complacency with regard to floodwaters and wilful governmental blindness in the utilisation of floodplains, we cause ourselves much pain. The pain is deserved, because it is self-imposed. We lack the will to deal sensibly with the risks of flooding.

We could do better. We could follow Queensland's lead and prosecute people for reckless behaviour in floodwaters, or make those whose recklessness requires them to be rescued pay the costs. We could also act decisively on flood warnings to protect our belongings, and evacuate promptly when necessary. And we could insist that governments and councils make sensibly conservative, long-sighted decisions on the use of floodplain land.