This book addresses the most pressing water resource issues in South Asia, particularly in relation to climate change and variability. This is a region characterised by abundant water during the monsoon, when devastating floods occur, and by scarcity of water and droughts during the dry period. These extreme events often cause substantial damage to infrastructure, property, livestock and human populations. Agriculture and other key economic sectors suffer greatly during these events. The results of climate and hydrologic models indicate increased vulnerability unless adequate adaptation measures are designed and implemented. Such policies need to rely on a framework that includes active participation of the stakeholders.