Economists view water supply as the quintessential example of a natural monopoly requiring government regulation. Yet, London’s piped water was provided privately for over 300 years until this became highly contested during the nineteenth century. Novel in its economic history approach, this book tells a story of how practices once considered innovative are later seen to be failing once we have new technologies, a larger market, new legal institutions, or different expectations. From the foundations of universal supply to the times of cholera and the end of private provision, this book follows the many successes and challenges that London faced in making long-run decisions about water infrastructure in a highly politicised environment which can inform those making similar decisions today.