The Australian Rainfall and Runoff (ARR) is a national guideline document and software for the estimation of design flood characteristics in Australia. It is published by Engineers Australia. It is a pivotal framework to the safety and sustainability of Australian infrastructure, communities and the environment. This is the 4th edition of ARR, after the 1st edition was released by Engineers Australia in 1958. The current revision process includes 21 research projects, which have been designed to fill knowledge gaps that have arisen since the 1987 edition.
The revised edition of ARR consists of: