Managing global water resources and providing water services to the world's people raises a continuing series of challenges, driven by increasing expectations, and a growing competition for water, which will be exacerbated by climate change. This paper explores how concepts of water governance and sustainability may help us to meet those challenges. Water governance is often equated with the role of government or management in the provision of water services. By contrast, we see governance as the system of actors, resources, mechanisms and processes, which mediate society's access to water. A broad conceptual framework is presented for the analysis of water governance, based on linkages between the resources available to society, the mechanisms that shape access to water and the outcomes of those mechanisms, both for people and the ecosystem. These linkages are mediated both by stakeholders and by management processes. It is argued that this conceptual framework offers a robust analytical tool for planning for sustainability as it is able to account for the complexities of water governance (of contexts, stakeholders, arrangements and uses). The paper concludes with observations about the ways in which the framework can be used to understand how different water governance arrangements produce variable outcomes in terms of sustainability.