The United Nations estimates that more than 2 billion people in over 40 countries are negatively affected by water shortages. Increasing demand for water has been identified as one of four major factors that will threaten human and ecological health over the next generation. As public health, development, economy and nature suffer, ensuring access to clean water is rising towards the top of government agendas. Water resources management is the aggregate of policies and activities used to provide clean water to meet human needs across sectors and jurisdictions and to sustain the water-related ecological systems upon which we depend. Knowledge that is crucial for water management is distributed across governments, non-governmental organizations and the water users themselves. In most circumstances, water management aims to address the interests of and integrate usage across hydrologically meaningful units, such as watersheds. Some management aspects, however, such as transboundary flows across multiple basins and inter-basin water transfers via channels or virtual water, may necessitate a broader geographical scope. Public participation aims actively to increase attention to and inclusion of the interests of those who are usually marginalized, e.g. politically disenfranchised minorities or poor people indirectly affected by water management. In this book, the authors identify successful mechanisms, approaches and practices for promoting public involvement in water resources management, including both conventional approaches and those based on information technology.