Water plays a key role in addressing the most pressing global challenges of our time, including climate change adaptation, food and energy security, environmental sustainability and the promotion of peace and stability. This comprehensive handbook explores the pivotal place of law and policy in efforts to ensure that water enables positive responses to these challenges and provides a basis for sound governance. The book reveals that significant progress has been made in recent decades to strengthen the governance of water resource management at different scales, including helping to address international and sub-national conflicts over transboundary water resources. It demonstrates that ‘effective’ laws and policies are fundamental drivers for the safe, equitable and sustainable utilization of water. However, it is also shown that what might constitute an effective law or policy related to water resources management is still hotly debated. As such, the handbook provides an important and definitive reference text for all studying water governance and management.