ABSTRACT
Flash floods are a life-threatening phenomenon, which also result in economic losses and social disruption. Handmer et al. (1988), for example, estimated direct economic losses for residential property in the Toongabbie Creek catchment (a subcatchment of the Upper Parramatta River, in the western suburbs of Sydney, Australia) as being approximately $5 million (1986 Australian dollars) for the 1% Annual Exceedance Probability (AEP) event. Commercial and industrial activities within the catchment were also estimated to have suffered economic losses of a similar magnitude. In the decade since these estimates were made, significant additional urbanisation, which decreases the potential response time of warning systems, together with inflation, make such potential losses an underestimate in present day terms.
