Rainwater harvesting: theorising and modelling issues that influence household adoption

Household adoption of rainwater harvesting (RH) systems recently boomed in Australian urban centres. As a sustainable supplement to the mains supply, water authorities regarded RH as a demand management device. Yet what actually motivated household RH adoption was not well understood. Burawoy's 'extended case method' was used to link grounded enquiry with 13 core theoretical concepts drawn from an original synthesis of ecological modernisation and diffusion of innovation theories. This framework means the household experience extends ideas drawn from existing theory to explore issues that influence the household RH adoption decision. The framework was interrogated with data drawn from a self-report survey of 560 homes. It accommodated 100% of the RH adoption issues identified by households. Further staged quantitative and qualitative analyses particularized these core concepts out to 36 discrete 'subfactors' which were used in discriminant function analyses. 17 subfactors contribute to a discriminant function grouping 89.2% of households to the correct 'adopter' or 'nonadopter' category (p<0.000). The model provides a transparent, robust, empirical basis for understanding the issues that influence household RH adoption and can be applied to social marketing aimed at facilitating further penetration of household RH.