How is ARR used?
With national applicability, balancing the varied climates of Australia, the information and the approaches presented in Australian Rainfall and Runoff are essential for policy decisions and projects involving:
- infrastructure such as roads, rail, airports, bridges, dams, stormwater and sewer systems;
- town planning;
- developing flood management plans for urban and rural communities;
- flood warnings and flood emergency management;
- operation of regulated river systems; and
- estimation of extreme flood levels.
What is new in ARR 2019?
Geoscience Australia, on behalf of the Australian Government, asked the National Committee on Water Engineers (NCWE) - a specialist committee of Engineers Australia - to continue overseeing the technical direction of ARR. ARR's success comes from practitioners and researchers driving its development; and the NCWE is the appropriate organisation to oversee this work. The NCWE has formed a sub-committee to lead the ongoing management and development of ARR for the benefit of the Australian community and the profession. The current membership of the ARR management subcommittee includes Mark Babister, Robin Connolly, Rory Nathan and Bill Weeks.
Key updates in ARR 2019
Available as “rough” draft
Peer reviewed and completed
Following practitioner feedback, a pdf version of ARR 2019 is now available
Limited functionality in web-based version
Additional pdf format available
Reflected best practice as of 2016 Climate Change policies
Updated to reflect current practice
Updated from the guidance provided in 1998 to include current best practice
Minor edits and reflects differences required for use in dam studies and floodplain management
Examples included for Book 9
Updated reflecting practitioner feedback
What was new in ARR 2016?
ARR was previously accessible only as a book on a fee for access basis. It is now publically available online and free of charge.
Data standards are now established to provide a consistent approach to collecting, analysing and managing flood information.
Terminology for concepts, measurements, methodologies and products for flood studies is now standardised.
Previous versions of ARR were developed when computer technology was emerging and calculations were often done by hand. Since the last update in 1987, there have been many developments in the understanding of rainfall-runoff processes and many new tools available for catchment simulation. ARR 2016 takes advantage of the significant advancements in computer technology, techniques and understanding of rainfall-runoff processes since 1987 and introduces changes to current practice. It is also based on Australian data, when previously it was based on USA data.
Key changes in ARR 2016
Intensity Frequency Duration (IFD)
Used BoM rainfall gauges
Presented as static A2 maps
Uses BoM and other agency gauges
Areal Reduction Factors (ARF)
Based on USA data
Not available for long durations
Based on Australian data
Based on jurisdictional based advice (personal communication only)
National advice for rural and urban catchments
Methods but no ungauged catchment advice
Australia wide advice
Average Variability Method Peak Burst
Patterns for less than 30 year average recurrence interval (ARI) and rarer than 30 year ARI
Temporal patterns based on historic records, multi pattern for each design quantile and complete storms, with pre burst considered.
At site Flood Frequency analysis
Probable Rational Method in some states
Bayesian of L moments
Regional Flood Frequency
Hydrograph Estimation Methods
Simple Design Event
Ensemble and Monte Carlo
Interaction of Coastal and River Flooding
ARR Project 18
Safety Design Criteria
People, vehicle and building hazard curves