Balcony dam overflow

https://www.metricon.com.au/new-home-designs/sa/banksia?category=facades&photo=banksia_classic.jpg&floorplan=27

The correct drainage of balconies and terraces is essential to prevent water damming and entering the building causing damage.

Drainage is particularly important where a parapet or hob fully surrounds a balcony preventing water from escaping the area.

It is a requirement to install a system designed to comply with the stormwater standard AS3500.3, which requires both a system of drainage designed for a 20yr ARI rainfall intensity and an overflow designed for a 100yr rainfall intensity.