It doesn't matter if it is 5% of a city or the whole city, it's not going to happen. The areas that were flooded now were mostly populated in 1974. There's a

It doesn't matter if it is 5% of a city or the whole city, it's not going to happen. The areas that were flooded now were mostly populated in 1974. There's a popular meme going around that huge areas of previously-vacant land was built upon. While that might be true in some instances of outer suburbs, in general the flooded suburbs of Brisbane were the same ones as all the previous floods. As I've already stated, if you want to clear the city from the low-lying areas, you'll have to forcibly acquire a large amount of private property, which is either an expensive (if the law is followed) route, or a suspension of the current law. So suggesting the low lying areas be forcibly cleared is clearly unworkable. And it involves acquiring and demolishing the majority of the CBD. If you think that is even remotely possible then I've got the Story Bridge to sell you. Everyone who purchases property in Brisbane is well aware of the 1974 floods. I know, because I purchased a property knowing full well it could be flooded one day as it was in 1974. And last week it was. But I'm not about to sell it or have the government confiscate it because it gets flooded once every 40 years. About the best thing that could happen is something along the lines of a) new developments must have critical infrastructure (electrical circuits etc) about the 100-year flood leve b) flood prone suburbs could have prominent markers, such as bands around power poles to remind people of previous flood heights. There's a popular one in the Breakfast Creek Hotel. c) new housing in flood zones could have a mandate not to use water soluble materials such as plasterboard in lower levels, and could be mandated to have the main living area above flood height. People with older houses often came out with no problems because the old houses were built with floods in mind. This idea of avoiding flood risk by avoiding waterfront areas is silly. By the same token, all residents should abandon Cairns and Townsville because of the cyclone risk. And cyclones in the north happen far more frequently, and with more devastation than Brisbane floods.