The new Intensity–Frequency–Duration (IFD) design rainfalls mark the first stage of an extensive Australian Rainfall & Runoff revision project.

While the new IFDs are derived from a longer and more extensive dataset, careful consideration is needed when they are used with 1987 Australia Rainfall and Runoff (AR&R87) design flood estimation techniques.

Guidance has been provided by Engineers Australia.


Should be used for:

  • Existing design flood studies
  • Probabilistic Rational Method

New IFDs (2013)

Should be used for:

  • Sensitivity analyses for new design flood studies
  • Revised Regional Flood Frequency analysis

How were the new IFDs estimated?

How do the new IFDs compare to the AR&R87 IFDs?

Can I use the new IFDs now?

New AR&R probability terminology

How do I incorporate climate change into the new IFDs?

Where can I find out more about the new IFDs?

More IFD questions and answers


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