Urban scholars have long proposed moving away from a conceptualisation of infrastructure as given and fixed material artefacts to replace it with one that makes it the very object of theorisation and explanation. Yet, very few studies have seriously investigated the role of infrastructure in co-shaping and mediating inequities. We use this paper to propose a way to engage with the technical intricacies of designing, operating and maintaining a water supply network, using these as an entry-point for describing, mapping and explaining differences and inequities in accessing water. The paper first proposes a methodological approach to systematically characterise and investigate material water flows in the water supply network. We then apply this approach to the case of water supply in Lilongwe, Malawi. Here, strategies for dealing with challenges of water shortage in the city have often entailed the construction of large water infrastructures to produce extra water. We show that the network’s material properties direct and divert most of the extra water to elite neighbourhoods rather than to those low-income areas where shortages are most acute. Our analysis shows how social and technical processes mutually constitute each other in the production and rationalisation of this highly uneven waterscape. We conclude that further theorisations of infrastructure as providing part of the explanation for how urban inequities are produced need to be anchored in the systematic and detailed empirical study of the network- in-use. Mapping the (changing) carrying capacities of pipes, storage capacities of service reservoirs and the strategic locations of new pipe extensions â to name a few important network descriptors â provides tangible entry-points for revealing and tracing how materials not only embody but also change social relations of power, thereby helping explain how inequities in access to water come about and endure.