I though the outrage for New Orleans was most about about the authorities response to the floods. In Brisbane the response is seen as being pretty good.
The last flood in 1974 was slightly worse and there have been worse ones in 1893 and 1841. So I guess you could say we are a bit prone to flooding. A damn was built in 1984 to mitigate the effects but it was close to full due to exceptional rain leading up to the main deluge. The damn still helped considerably and allowed them to block some water flow at high tide, but there is some suggestion that more proactive emptying earlier would have helped.
The Queensland Police facebook page http://www.facebook.com/QueenslandPolice is pretty interesting. Nearly everyone I know subscribed. Did a great job keeping people up to date, stopping panic, dispelling rumors, organizing workers. Pretty much the first time in my life I've appreciated Web 2.0 :) (Well, until the mobile towers went down...)
One thing that the whole event showed was how the government websites don't stand up to high loads whereas the mega sites (google, facebook, twitter) have no problem with such a localised situation. To cope with emergencies like this, the relevant govt agencies will have to look at distributed architectures possibly incorporating offshore cloud based services.
I think the police usage of Facebook was inspired. It's free for the police, there's an existing distribution mechanism in place, it's highly scalable and it's canonical, which can quickly cut down rumors. Twitter became a festering swamp of rumors and BS, whereas being subscribed to the QPS facebook page meant high quality information.
I tried to get onto the Moreton shire council to find a road closures list, and was faced with a downloadable MS Word document. There's the two extremes for you.
One thing that governments everywhere should learn from this is that maintaining and using Twitter and Facebook from established, trusted accounts is a very good way of getting information out there. Even if only a tiny fraction of the population are subscribed, they can quickly disseminate information to neighbours and family members.
The last flood in 1974 reached higher levels in Brisbane, but I haven't seen anything explaining to what extent (if any) the flood levels were lower this time because of the dam? Would it have been even worse without the dam?
At the very least it let them control the flow a little bit so we didn't just get hit by a massive wave all in one go.
I think the general consensus is that the flooding would have been worse than 1974 had the dam not mitigated what it did. Investigations and modelling will determine to what extent the releases from the dam increased the flood level.
I expect the outcome will be a new operating manual for the Dam, and more frequent minor flooding in keeping with an aggressive plan of keeping the dam at 100% (water storage) level, leaving the extra 100% of flood mitigation level free as soon as possible.
Another possible outcome may be more dams on some of the other river systems, such as the Bremer river.
The last flood in 1974 was slightly worse and there have been worse ones in 1893 and 1841. So I guess you could say we are a bit prone to flooding. A damn was built in 1984 to mitigate the effects but it was close to full due to exceptional rain leading up to the main deluge. The damn still helped considerably and allowed them to block some water flow at high tide, but there is some suggestion that more proactive emptying earlier would have helped.