TESTING NEW DESIGN FLOOD ESTIMATION TECHNIQUES FOR CATCHMENTS ACROSS AUSTRALIA

"Australian Rainfall and Runoff" (ARR) is Australia's primary guideline for flood estimation and it is currently under revision. As part of the development of the new edition, existing methods have been carefully reviewed considering international and Australian best practice, recent research and on-going data collection. An important part of the revision is a design flood estimation procedure for small to medium sized ungauged catchments to apply for all of Australia. To assess performance and to assist in acceptance, an extensive testing programme for the new procedures has been undertaken (and is continuing) in a wide range of environments around Australia to ensure that the new procedures provide a pragmatic, consistent and realistic methodology. Practitioners who apply procedures in ARR cover a wide range of skills sets and the procedures are applied to applications ranging from minor routine projects to advanced and complex applications. The aims of the testing program are to ensure that when all components of the design flood method are combined that a robust answer results, to find any inadequacies in the methodology prior to final publication of the new ARR, and to educate engineers in the use of the new methods. The testing program involves over 150 companies, individuals and academic organisations from across Australia. Participants range from specialist flooding firms to those who only occasionally work in this space. This paper covers preliminary stages of the testing programme and provides valuable lessons for continuing development.