Rainwater harvesting for domestic use: A systematic review and outlook from the utility policy and management perspectives

In recent years, water insecurity has been reported as a problem of worldwide concern. Rainwater harvesting (RWH) for some domestic uses is regarded as a path out of this situation. However, in some localities, RWH has been the sole water source for all domestic and non-domestic uses. In recent times, research in RWH has gained more traction from the operationalization and engineering perspectives. However, for direct rainwater usage to become a societal norm and generate significant societal benefits, studies in RWH must assess the alignment of outcomes from policy and management perspectives. Therefore, a comprehensive literature review of 83 collated papers on RWH is conducted in two stages. First, a systematic review of the literature is performed to identify the thematic content (structure of the literature, problem orientation), contextual application (technical and social considerations), and theoretical alignment scope (neo-institutional theory, agency theory, and ecological modernization theory). Second, gaps in the literature are identified, and theoretical alignment of the ideas from policy and management perspectives is proposed to advance RWH research. Key findings are: (1) despite RWH being aimed to provide social benefits, the present literature is constrained in supporting social policy-making and management of rainwater as a public utility system; (2) policy and governance frameworks that include socio-economic and socio-environmental pragmatism are needed to achieve RWH programs realistically; and (3) modeling of RWH systems requires considering spatial variabilities, policy evaluations, and governing theories. RWH has the potential to have a central position in water resource management worldwide.