Rainwater tank households: water savers or water users?
This paper provides the first published post-installation analysis of retrofitted rainwater tanks and their effects on mains water consumption. The study aimed to determine the average mains water reductions achieved in households with recently installed rainwater tanks and compare this figure with wider community consumption. The social and cultural impacts of rainwater tank ownership were also explored to understand how rainwater is used and perceived. The results show that during the period of analysis, the drought years of 2005–2007, 7125 or 8% of Illawarra households installed a tank. Comparison of mains water consumption for two years before and after installation shows that rainwater tank households reduced their mains water consumption about the same amount (10.26%) as the wider community (10.8%). The social and cultural components reveal three main groups of households. The largest group, water users, had a desire for water autonomy and independence to continue previously enjoyed water practices that had been restricted. Among a light green group, tanks were part of a package of overtly pro-environmental behaviours that did not necessarily change consumption patterns. A frugal group, many of whom had been raised in rural areas, were the main water savers. Perception of tank water quality was shown to be an influential determinant of how rainwater was used, particularly for connections internal to the house. This study shows that rainwater tanks have the potential to achieve significant water savings, but if water-intensive behaviours are not modified, and rainwater tanks are not plumbed indoors, the potential of this alternative water source will not be met. Currently, rainwater tanks facilitate water users as much as water savers.