Using choice experiment to inform water conservation initiatives under different water scarcity backgrounds to improve water security

To improve the effectiveness of water management policies aimed at water conservation, human behaviour and public preferences regarding water availability and supply are expected to play a key role but must be better understood. Water scarcity status can strongly influence stakeholders’ support for water resources management and significantly drive public willingness to pay (WTP) for water conservation measures. To account the full benefits of adopting conservation measures to improve urban water security, it is of paramount importance to understand what prevents people from investing in practices that protect and improve water yield in basins responsible for their water supply.

The main objective of this study is to inform water conservation programs in Brazil about public preferences for improving water security aspects (i.e., water supply and conservation measures) in the basins feeding water to urban city centers. To also test for possible influence of water scarcity experiences on public preferences for conservation measures and water security aspects, a choice experiment was carried out in two capital cities in Brazil that have faced different water restrictions and rationing efforts: the Metropolitan Region of Sao Paulo and Campo Grande city. We interviewed 400 people in each city in November 2021, and simple multinomial logit models using Apollo in R were used to estimate WTP for the reduction of the frequency and duration of future water shortages, as well as three different conservation practices: agroforestry, afforestation, and water harvesting technologies.

A model is estimated for each city, the Metropolitan Region of Sao Paulo (MRSP) and Campo Grande, as we wanted to test whether the different public experiences with water use restrictions and rationing lead to a different public WTP for water conservation measures. In both samples, the status quo alternative significantly decreased respondents’ utility, indicating an avoidance of the current water security status even though the respondents faced different water shortage experiences in each city. Twice as many residents in MRSP (77%) in the survey faced at least one episode of water restriction in the last decade than Campo Grande residents (36%). As a result, a decrease in the duration of water supply interruption has a significant effect on the respondents’ utility, considering the model estimated for the MRSP. In contrast, a reduction in the frequency of future water shortages was not significant. In Campo Grande, none of the attributes related to water security significantly impacted public preferences. Only the proposed measures had a significant influence on the utility of the respondents form Campo Grande. Our findings indicate that previous experiences with water scarcity affects not only the preferences for conservation initiatives, but also whether society perceives that these measures contribute to improving the water security. This study provides insightful information to policymaking for effective initiatives to improve water security with the involvement of society. Unveiling people’s preferences for water conservation practices and improvements in water availability and supply is fundamental to promote protection and conservation of water ecosystem services provided by river basins and, consequently, improve current and future water security.