Martine Visser, M.J. Booysen, Johanna M. Brühl & Kenneth J. Berger. Saving Water at Cape Town Schools by using Smart Metering and Behavioural Change. EfD Discussion Paper Series DP 19-18.
Cape Town made world headlines in 2018 as a major city on the brink of seeing its taps run dry. Its predicament drew attention to the challenge that water scarcity presents for cities in the 21st century. Globally, over four billion people face severe freshwater shortages and this number is expected to rise (Mekonnen and Hoekstra, 2016). The Water Resources Group (2017) predicts that by 2030 there will be a 40% gap between freshwater supply and demand if business-as-usual water management continues. Clearly this challenge requires supply-side solutions, but water demand management is increasingly being recognised as an important aid to ensuring a sustainable water supply (Arbués et al., 2003; Russell and Fielding, 2010).
Traditionally, water demand management has relied on the use of direct incentive augmenting schemes and pecuniary policy such as high tariffs. However, there is increasing evidence of the effectiveness of behavioural insights and nudges in changing water usage behaviour (Sønderlund et al., 2014). Nudges can be an attractive alternative for policymakers because they are cost-effective and easy to implement. Our study investigated how nudges can be applied in schools.
Schools offer an ideal platform for promoting conservation behaviour because they are big water users and because the interventions will have a ripple effect in the community (Booysen et al., 2019a). We conducted a randomised control trial at a sample of 105 schools in the Western Cape, South Africa, in which we tested two behavioural treatments: information feedback and a social comparison in the form of an inter-school competition. We used data from smart water meters to track usage patterns accurately and give the schools detailed usage feedback. Thirty of the schools constituted the control group, receiving smart meter installation but no usage feedback.