This article provides a synthetic account of the historical development of London's water supply system within its wider national context, and addresses the current organizational setting of the water sector. Particular attention is paid to the post-Second World War period, which marked a transition towards integrated water management in England and Wales, a trend that has been consolidated since the 1970s. The article emphasizes the continuities and contradictions arising from the different combinations of public and private management strategies characterizing the UK water sector, and their implications for the sustainable management of water resources. It argues that there exists an in-built contradiction in the current institutional framework between the profit-oriented rationale of the private operators and the goals efficiency, equity, and environmental sustainability pursued by the water regulators. Within this framework, it highlights the key policy issues facing the metropolitan water systems, and suggests what their most likely trajectories might be in the foreseeable future.