Australian Rainfall and Runoff Revision Project 5: Regional Flood Methods: Stage 3 Report

The most commonly encountered hydrological problem associated with estimating flood flows is that of estimating the flood flow of a given Annual Exceedence Probability (AEP) at a location where no historical monitored information exists. Numerous alternative techniques have been developed in the different regions (primarily, the states) of Australia to provide flow estimates in ungauged catchments. The current diversity of approaches has resulted in predicted flows varying significantly at the interfaces between regions. There is a need to develop generic techniques that can be applied across the country, to test these techniques, and to develop appropriate guidance in their usage.