Multicriteria Decision Support for Selection of Alternatives Directed to Integrated Urban Water Management

The management of water resources in medium and large cities has been changing in recent years, mainly as a result of climate change and the sharp increase of urbanization. In addition to the traditional solution of expansion of water supply, an approach that integrates technological alternatives of demand management in the infrastructure of urban constructions is proposed herein. However, these facilities are often more complex and expensive than conventional ones, being also challenging to achieve a balance between costs and benefits. While the environmental, social, and engineering benefits seem obvious, expressing them in monetary terms is usually a challenge that cost-effectiveness do not respond satisfactorily. Therefore, this research uses the Fuzzy Analytic Hierarchy Process multiple criteria method to rank three main alternatives (rainwater harvesting system, gray water recycling system, and water saving devices) that can be applied in low-income residences in Brazil. For this purpose, this paper considers criteria normally used in this type of analysis such as economic, technical, environmental and social criteria but also includes the local population acceptance and the evaluation of experts. The main results suggest that the most appropriate alternative is the use of water saving devices and that there is also a need for public policies that offer financial incentives to the population and prevent socioeconomic conditions from inhibiting the adoption of water conservation practices.