Willingness to Pay for Rainwater Tank Features: A Post-Drought Analysis of Sydney Water Users

The Millennium Drought across Australia during the 2000s placed cities under pressure in providing urban water security. In Sydney, Australia's largest city, a comprehensive water demand programme triggered a significant reduction in per capita water consumption. The water demand programme included incentives for the installation of rainwater tanks. This paper explores the willingness to pay (WTP) for rainwater tank features in the post-drought context. Rainwater tanks have been demonstrated as an effective measure to reduce mains water demand, but they also provide broader environmental and economic benefits, such as the reduction of urban runoff to waterways and deferred capital investment in augmenting capacity of water supply system. Therefore, there is the need to better understand WTP for rainwater tank features across the community. An online survey was administered to a sample of Sydney households, with 127 respondents completing a rainwater tank choice experiment that explored their WTP for different rainwater tank features and the socio-psychological constructs that might influence their tendency to adopt rainwater tanks. The results demonstrated that householders surveyed valued slimline rainwater tanks, as they are likely to be less obstructive, particularly given the trend for smaller lot sizes and increased building size. Householders also placed greater value on connecting the rainwater tank to outdoor demands, which may be influenced by perceived vulnerability of outdoor uses to water restrictions relative to indoor uses. The survey analysis also identified that the householders most receptive to installing a rainwater tank are likely to be conformists, who compare themselves to peers, and spend significant effort when making decisions, and are already taking actions to conserve water. The findings are of significance when targeting future education programmes and designing financial incentives to encourage rainwater tank adoption.