I'm amazed the forecasts are as accurate as they are. Melbourne forecasts always seemed to be wrong when I was a kid.
Don't forget the managers of the Brisbane dam are the subject of a class action suing them because they didn't manage the risk conservatively enough. They thought they would wait a bit too see if the rain really was going to be off the scale as it was predicted. As it turned out, it was off the scale. The dam that flood proofed Brisbane was overloaded by an unprecedented amount of rain.
Damned if you do, damned if you don't.