This paper examines whether key legislative and regulatory frameworks for the provision of water services in Sydney, Australia, successfully support the complex task of planning and managing urban water systems to balance water security, cost and sustainability considerations. The challenges of managing urban water systems under a changing and uncertain climate became starkly apparent during Australia's ‘Millennium Drought’, a decade-long period of extremely dry conditions throughout the 2000s. As the drought progressed, several state and territory governments assumed control of planning and approvals processes in order to implement large water-supply infrastructure projects with great urgency. However, at the end of the decade La Niña rains saturated catchments, spilled over dam walls and devastated several communities with flooding. Analysis of the frameworks for third-party access, private-sector participation, planning, and water-conservation initiatives reveals that the rules, roles and responsibilities of the many actors are interlinked but not always effectively integrated. The introduction and expansion of competition in the urban water industry are an ongoing experiment with great influence on the governance of the sector and the ways in which water services are planned for and provided.