The Australian Rainfall and Runoff (ARR) Guidebook, a vital resource for flood estimation and water management, has undergone an important update with the release of Version 4.2 at the end of August 2024. This new edition includes significant revisions to the chapter on climate change (Book 1, Chapter 6), aligning the guidelines with the latest international climate research and best practices, particularly those outlined by the Intergovernmental Panel on Climate Change (IPCC) in its Sixth Assessment Report (IPCC 6).
The update is the result of an 18-month project initiated in late 2022 by the Australian Government’s Department of Climate Change, Energy, the Environment and Water, in partnership with Engineers Australia. The project aimed to integrate the most up-to-date climate science and projections into flood design standards.
At the core of this effort was a comprehensive literature review of hydroclimatology under climate change, with a focus on design flood estimation. The research findings, peer-reviewed and published in a leading international journal, formed the basis for the practical flood guidance now incorporated into the ARR guide.
Industry professionals extensively reviewed and provided feedback on the updated guidance prior to its finalisation. The project, funded by the National Emergency Management Agency through the Disaster Risk Reduction Package, is designed to strengthen Australia’s preparedness for climate change-related flood risks.
Click below to view the full guide and updated ARR resources website.
