This study explores the politics of urban water supply and sanitation delivery in the city of Colombo, Sri Lanka, where improvements in coverage have been achieved within a national context characterised by almost three decades of civil war. Though Colombo is by no means an unqualified success, or representative of the country as a whole, this isolated case offers an opportunity to unpick the role of politics in a story of relative progress. It also presents a possibility to compare the politics of two closely related but nevertheless technically and organisationally distinct services, and to examine whether and why these sectors attract different political dynamics. The broad conclusion is that pervasive features of the political economy environment can interact with sector-specific characteristics to produce particular political dynamics around the delivery of different services. Both water supply and sanitation have been able to function effectively because these political dynamics have remained relatively stable over the medium term, in spite of the wider context of civil war.