Where is Queensland up to with flood management?

The result was that residential and other development was encouraged on the floodplain. Brisbane's vulnerability to flooding was actually increased, not lessened. The 2011 flood, which peaked at the Brisbane Post Office gauge at a level roughly a metre below that reached in 1974, actually saw more properties inundated than had the earlier event. Between the two floods, the dam became a reason to increase the vulnerability of the community. The financial costs of the 2011 flood in Brisbane, after adjusting for inflation, were probably twice those of the 1974 event.

A paradox arose. A flood mitigation measure had the effect of intensifying the flood problem.

Therein lies a lesson. The core of the flood problem lies in our use of land. Every generation of Queenslanders has made it worse by building more dwellings, business premises and public facilities on floodplains. No generation has recognised, let alone acted upon, the consequences of this fundamental truth. And the cost goes up and up. And then up some more.

Now, what Queensland looks proposes to do is to treat the problem of flooding as one of water management rather than land and community management. Thus it will fight floods by building dams and levees and raising roads. We seem incapable of modifying communities to make it easier for them to live with floods. We are using one set of strategies, but ignoring another and more fundamental one as we have for decades.

Queensland appears unlikely to make a significant effort to restrict urban development from places which are guaranteed to flood periodically. Nor is it probable, judging from what has been announced so far, that the state will invest in measures like house-raising or buying back properties which have histories of frequent inundation. Interestingly, in 2006 Campbell Newman as Lord Mayor of Brisbane sought state government help with just these measures to alleviate the problems of flooding on Brisbane's creeks. He was unsuccessful.

And there has been little discussion about increasing the ability of people who live in flood-liable areas to deal with flooding. Specifically, these people need to better understand the forecast flood heights at which their properties will be affected and in preparing for which they should take action to protect items of value. Clearly, this understanding is lacking in flood liable communities at present.

Too often residents do nothing until the floodwaters are upon them, by which time the protection of items of monetary and sentimental value is difficult. The evidence lies in the piles of household and commercial items on the footpaths of towns and cities after floods, and later in hikes in property insurance premiums. It is clear that flood warnings have not sufficiently encouraged property-saving actions like raising items or moving them to higher ground. Strangely, this is little recognised in post-flood enquiries. We need to help floodplain residents to deal with the inevitability of flooding by responding better as floods develop.

And we should be preventing the problem from becoming worse (for example by prohibiting all but unavoidable building on floodplains) while at the same time instituting programmes by which some at least of the accumulated legacy of past developmental follies is reduced by strategies of 'planned retreat' from floodplains. We will never achieve that in totality, of course: it would be prohibitively expensive. But we could remove buildings from the worst affected locations.

But instead of tackling the problem broadly with a wide range of measures, Queensland aims to employ partial, engineering-based works. Controlling floodwater will be the principal method. A cynic might say that dams are more visible than effective, and that they are beloved of governments (and indeed communities) because of that very visibility. The reductions they bring to flood heights are smaller than might be supposed, determining the best water release strategies from the small number of gated dams is difficult, and wherever dams are built the rains that produce flooding can fall downstream of them. Much of Brisbane's 2011 flood came from rain that fell below Wivenhoe Dam and over the tributary catchments drained by the unregulated Bremer River and Lockyer, Warrill and Oxley creeks.

Reducing floodplain development, of course, carries political risks because it limits how landowners can utilise their land. And educating people on how to protect their interests as floods approach is less tangible than building dams and levees.

Brisbane Lord Mayor Graham Quirk has recognised the difficulty of changing the rules about building on floodplains. People who own land have rights, he notes. So they do, but those rights are producing big increases in the cost to the public purse, both in handouts to flood victims who have exercised their rights and in the repair and replacement of infrastructural assets. How far should respect for property rights be allowed to go on intensifying community vulnerability and increasing the costs of dealing with it?

Usage rights in relation to land are not absolute, and decisions of governments can disadvantage some landowners. The evolution of modern town planning, indeed, prevented some owners from using their land in certain ways ─ but important public benefits accrued including the separation of residences from noxious industry. Meanwhile the Queensland Planning and Environment Court periodically refuses owners' land development proposals on public interest grounds, and over time regulations on development on floodplains have tended to become more stringent.