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Apply the latest ARR updates with the new Watercom Climate Change Rainfall Modifier.

Seen the new updates to ARR? Apply the latest climate change science to your models using the new Watercom Climate Change Rainfall Modifier!  

A final draft of Chapter 6, Book 9, of ARR 2016 was released in January 2019.  New in this draft is the advice to use the published pre-burst rainfalls for the 60 minute rainfall burst duration for all burst durations less than 60 minutes.  This means the Initial Loss – Continuing Loss model recommended in ARR 2016 can now be used for urban drainage work.  DRAINS has provided the ARR 2016 procedures since January 2017.