An increasing number of regions in the United Kingdom (UK) are experiencing water shortages. The universal installation of household water meters has been identified as one way to reduce demand on limited supplies. The general consensus among policy-makers and water practitioners is that meters ‘work’ by providing a financial incentive to residents to use less water. Recent studies however, suggest that mechanisms that drive changes in water-user behaviours are more complex and context-dependent. Using an approach developed in the field of program evaluation, this paper examines policy-maker and water practitioner understandings of how a current universal metering program in the south east of the UK ‘works’. These understandings are then compared to how water meters are managed and accepted at a household level. The findings demonstrate how ‘Realistic Evaluation’ (Pawson & Tilley, 1997) can be used to gain a deeper understanding of how technological interventions ‘work’ in complex social systems
