By combining scholarship on modernity, urbanization and territory, this paper analyses how urban-based visions and ambitions have been realized in hydropower development and specific water access and control arrangements in the Rímac watershed in Lima, Peru. The discourses that sustained and promoted hydropower plant construction and associated development projects in the watershed are scrutinized, showing how the dream of conquering nature through engineers' technical skills was enmeshed with political agendas and visions of modernizing not only nature, but also people. Besides the historical analysis, the paper also explores how historical physical-ecological, legal, social and symbolic reconfigurations continue to shape hydrosocial relations between the city of Lima and the Rímac watershed. Analysing the current management of the watershed's highland lakes and community water use from the hydropower company's tunnels shows how the history of the Rímac is not a clear cut story of water deprivation but rather of complex, entangled, multidimensional relations and dependence. In the context of increasing pressure on water resources, the socio-territorial arrangements and the watershed's history itself are becoming matters of discussion.