The first decades of the 20th century were a great period in urban municipal politics that gave rise to the modern theory and practice of public health. In Toronto, the iconic R.C. Harris Filtration Plant (1941) stands as an emblem of modernity and the marvels of hydraulic engineering that assured every citizen of the social right to clean water. We no longer celebrate the material networks of water supply such as R.C. Harris and his public works department fought to achieve; filtered H20 has become another commodity with no reference to the production process. In this thesis I explore the local, historical specifics of water issues embedded in this site and suggest ways that they might contribute to the renewed visibility of hydraulic infrastructure; a re-imagined materiality that might in turn inspire a more sustainable, collective water citizenship.