Scaling-up rainwater harvesting in Mexico City: A socio-environmental review

In Mexico City, one of the world's largest megacities, the dissemination of rainwater harvesting (RWH) facilities has been supported by the local government to address the capital's entrenched problems of unequal water access and distribution. In this context, the present chapter analyses the scaling-up journey of this alternative, focusing on the implementation challenges of Cosecha de Lluvia, the first massive RWH social programme, and its relevance in the context of climate change. From a socio-environmental perspective, the chapter reflects on the limitations and achievements of the RWH efforts promoted by the city government, emphasising the ongoing necessity for social and institutional innovations to ensure equitable access to water, particularly for marginalised populations in informal settlements. This chapter concludes that addressing water scarcity demands more than technological solutions, urging deeper institutional and political changes to address its root causes. In sum, this chapter not only offers a critical review of Mexico City's experience with scaling up RWH infrastructure but also underscores the broader implications for urban water management and social equity.