Redrawing the Hydrosocial Cycle Through Treated Wastewater Reuse in the Metropolitan Area of Barcelona

Increasing economic, social and environmental limits to the development of conventional water supply sources have shifted water resource frontiers to alternative sources, most notably desalination and wastewater reuse. In the past few years, critical scholarship has been prolific in its exploration of how desalination may redraw the hydrosocial cycle in different geographies; wastewater reuse, however, has received much less attention. In this article, we aim to contribute to a critical exploration of the implications of different types of wastewater reuse for urban purposes. We do so through an examination of the case of the Metropolitan Area of Barcelona (AMB), an area with a fragile water supply system that has been undergoing a harsh drought in 2022/2023. We examine two examples of how treated wastewater may enter the residential sphere. The first involves the reuse of greywater for toilet flushing in residential buildings. The second is linked to the possibilities that advanced treatment of wastewater open up in terms of making urban water systems more robust and more resilient to recurring droughts; this advanced strategy enables both the bolstering of indirect reuse of reclaimed water for potable purposes and direct reuse through the development of dual networks of supply in new urban areas. In this paper, we attempt to unravel the different economic, social, environmental and political implications of those interventions through the lens of the hydrosocial cycle and resource frontiers. We triangulate a critical review of policy documents with informal conversations with policymakers and, in one of the case studies, previous research.