I think it ought to be the responsibility of Insurance Companies and housing Lenders to refuse cover or loans for housing in flood plains. That persons intending building in those areas do so at their own risk and finance. That City council regulate that living areas be above 1 in 50 year flood levels. There are high areas in Brisbane and Ipswich that are flood free. Commercial premises, Company offices and sporting fields could occupy river frontage but occupied areas must be 1 meter above 1 in 50 year flood levels. Lower levels be used for car parking etc.