There's a myth that you often hear about old Brisbane houses, that they were built on stilts for ventilation, so that air could swirl under them in the hot summer months. It's one of those stories people mention every now and then. But it's not true.

The stilts allowed wooden houses to be built into the sides of hills and Brisbane is nothing if not a hilly place. It's part of its charm. The ones holding up the front of my house, for example, are over three metres tall. At the back, they're no more than a foot above the ground. Stilts are practical.

The other major reason for this architectural peculiarity was flooding. In the Brisbane of my youth, water flowed across the concrete slab under the house whenever we had a major downpour. Not masses of water, just a steady wash that had come from the neighbour's yard further up the hill.

Until the 1980s it was rare to find a house in the inner-city that wasn't elevated. But then several things occurred: the city's population grew much larger and so did the houses. People began removing the stilts and building in underneath - new bedrooms, living spaces, etc.

At the same time, the climate began to change. The Christmas/new year rainfall seemed not so heavy anymore and not so long. And then during the long drought of the mid-2000s, many people in Brisbane found it difficult to remember that the city had ever been sub-tropical at all, that heavy rain and flooding were part of its DNA.

I remember just a few years ago a builder friend of mine saying that there was going to be trouble. That many of the houses were no longer being built to suit the Brisbane climate. That we'd all become so used to dry conditions that we'd forgotten to build for the wet.

His voice came back to me on Wednesday as I stood at the edge of an expanding brown river: a great mass of steadily rising water that had just swallowed Rosalie Village - a trendy cafe area which my son and I had visited only the day before. Shops, houses and buildings built close to the ground had no chance of staying dry.

Of course, it isn't just that we've been building in an incorrect way. The big problem for a city like Brisbane is that we've also been building in the wrong places.

Three years ago I lived in a newly-constructed house built next to a major creek. There was only a thin strip of parkland separating the wooden fence from the gully. But there were other houses in the area built much closer; and during the short time that I lived there, I watched as developers were allowed to construct an apartment complex of several dozen dwellings literally overlooking the waterway. The back door of one of the ground floor units was no more than a few metres from the creek.

How, I wondered at the time, was that ever allowed. And yet, if you travel around Brisbane you'll find many examples of houses and buildings built in places where water is clearly meant to flow - and eventually does.

In an effort to meet the housing needs of a growing population, government authorities in south-east Queensland (of all political persuasions) have been pursuing policies that promote greater urban density: trying to squeeze more and more people into existing areas of the city, including those areas which have historically experienced flooding.

One of the worst hit suburbs during this current crisis has been Milton. Large tracts of Milton went underwater in 1974 and have experienced minor localised flooding on a regular basis ever since. Yet Milton is one of several designated zones for increased development, including new plans for high-rise residential towers.

Another Brisbane suburb that's also earmarked for higher density development is West End - again, a low-lying area of the city with a long history of flooding. West End was one of the first areas to go under in 1974 and was so again in 2010.

Earlier this year, when researching a program on food security for Radio National, I spoke with social researcher Dr Rebecca Huntley. One of her arguments was that poorly thought-out government policy had allowed urban sprawl to take-over the nutrient rich, productive farmlands that once fringed our cities and were a source of locally grown food.

In other words, in a country where good farming soil is at a premium, we've allowed new suburbs to be built on some of our best land.

Perhaps, in the wake of what's happened in Brisbane this week, it might also be time to question whether that same expansionist urban development mentality has resulted in an unwise push to build more and more dwellings on some of our worst land as well.

And a footnote of interest: Some of the defining images of this flood have been of luxury boats and pontoons washing down the Brisbane River and crashing into pylons. Those images speak a great deal about the way in which Brisbane has changed since the mid 70s.

It's worth pointing out that while many of the same place-names are being mentioned in this flood as in 1974, the affected suburbs themselves have changed remarkably between those two dates. Back in 1974 the inner city suburbs of Brisbane were yet to be gentrified, so the people whose homes were inundated in places like New Farm and Milton and Highgate Hill were largely less well-off.

In 2010, the residents of the inner-city are among the most prosperous. And there are none so wealthy as those who live right on the river. It will be interesting to see whether that significant change in demographics and income-levels ends up impacting on the speed and cost of the recovery this time around.

Antony Funnell presents Future Tense on ABC Radio National