Chile’s free-market economic and political reforms, designed and implemented under Pinochet’s military regime (1973-1990), have been important in discussions of neoliberal public policy and environmental governance. However, understandings of how and why these reforms unfolded often overlook the complex power dynamics involved. This paper examines the role of water in consolidating the design, implementation and outcomes of Chile’s neoliberal programme, through the contested production, retention and reform of the 1981 Water Code. Drawing on the idea that water and power are mutually constitutive, it demonstrates the significance of the transition to private tradable water rights with minimal state regulation not only for changing social relationships with water, but also for consolidating the neoliberal programme and the ambitions of the military regime, government technocrats and business conglomerates. I make three related arguments: first, that water was more central to the formation and effectiveness of the neoliberal programme in Chile, and the ambitions of its core supporters, than hitherto acknowledged; second, that political interest groups, and their alliances, can play crucial roles in neoliberalising nature; and, third, that water institutional reforms consolidate power relationships and produce waterscapes in particular ways.