Rainwater tanks in multi-unit buildings: A case study for three Australian cities.

Abstract: Rainwater tanks have become popular in large Australian cities due to water shortage and greater public awareness towards sustainable urban development. Rainwater harvesting in multi-unit buildings in Australia is less common. This paper investigates the water savings potential of rainwater tanks fitted in multi-unit residential buildings in three cities of Australia: Sydney, Newcastle and Wollongong. It is found that for multi-unit buildings, a larger tank size is more appropriate to maximise water savings. It is also found that rainwater tank of appropriate size in a multi-unit building can provide significant mains water savings even in dry years. A prediction equation is developed which can be used to estimate average annual water savings from having a rainwater tank in a multi-unit building in these three Australian cities. [ABSTRACT FROM AUTHOR]