In Lima, residents are fundamental co-creators of the urban water infrastructure, taking up various roles in the operation, maintenance, and expansion of the water distribution system. As Lima’s potable water company presses the transition from decentralized and auto-constructed to centralized and digital, this article explores how the implementation of digital infrastructure reconfigures the role of residents in the water distribution system. Our analysis draws on an ethnographic research approach, using formal and informal interviews, and focus groups in three areas representing Lima’s diversity in settlement categories and types of water consumers. By analyzing the digitalization of Lima’s water infrastructure through the perspective of its residents, this research contributes to understanding how top-down, digital governance practices mediate the agency and everyday experiences of people living in Southern cities. We observe that the digitalization of the water infrastructure marginalizes the participation of the ‘expert-amateur,’ a crucial role in the development of urban in the Global South, while providing more space for the ‘smart citizen’ to engage in infrastructuring. This article concludes that to overcome the perpetual creation of the center and the periphery through digitalization, urban infrastructure management should be sensitive to residents’ diverse strategies in managing resources.