Rainwater harvesting in the UK: a strategic framework to enable transition from novel to mainstream

The approach to water management worldwide is currently in transition, with a shift evident from purely centralised infrastructure to greater consideration of decentralised technologies, such as rainwater harvesting (RWH). Initiated by recognition of drivers including increasing water demand and increasing risk of flooding, the value of RWH is beginning to filter across the academic-policy boundary. However, in the UK, implementation of RWH systems is not straight forward; social and technical barriers, concerns and knowledge gaps exist, which currently restrict its widespread utilisation. Previously, these issues have been examined independently. The research described in this thesis highlights the need for interdisciplinary working to lower the barriers and resolve the concerns. Consequently, a combination of social and engineering research perspectives, methods and analysis is utilised to achieve the aim of the research: the production of a strategic framework to support the implementation of RWH in the UK. The framework is the culmination of empirically derived social and technical evidence bases including: surveys with householders and architects; interviews with small to medium enterprises (SMEs); a design and performance evaluation of a non-domestic RWH system; non-domestic water closet (WC) monitoring to develop a demand profile and a water quality study and health impact assessment (HIA) of a non-domestic RWH system. Results indicate that householders were willing but not able to implement RWH, due to financial constraints and perceived maintenance burdens. For SMEs 5 ‘implementation deficit categories’ were identified, which undermined their ability to implement. The use of continuous simulation tools, with appropriate data, need to be promoted and the non-domestic demand profile derived was distinctly different to the well-established domestic profile, yielding implications for system design. The non-domestic RWH system was able to achieve an average water saving efficiency of 97% for the period monitored and the HIA quantified the risk to health as being within the recognised screening level. Triangulation of the results into an integrated socio-technical evidence base facilitated the identification of three core strategy aims, their corresponding actions and actors (stakeholder groups). The overall strategic framework is presented in the form of a Venn diagram. It is unlikely the comprehensive nature of the strategic framework would have been achieved, if the interdisciplinary process had not been undertaken. Therefore adoption of a socio-technical approach to implementation is vital, if RWH in the UK is to transition from novel to mainstream.