This paper describes the evolution of the piped water and sewer system in Kampala, Uganda, between 1920 and 1950, and considers the influences this had on the city"s later development. Large-scale systems for water and sanitation are associated with an inertia that makes them slow to adapt to a new economic, social or environmental context. It is important to know the history of such systems in order to understand issues of sustainability today. This article shows how the piped water and sewerage systems were introduced to serve mainly the more affluent groups in society. Although the systems were economically and socially sustainable in the colonial context, inherent features of the systems made universal service coverage problematic from an economic point of view. Policy makers need to acknowledge the historic influence and the inertia of systems in order to address current shortcomings in water and sanitation provision, and create sustainable and equitable service provision.