This book provides an ecosystem perspective in addressing the water resource management issues in the South Asian region. It argues that aspects such as sources of water, its distribution and users; land “water interrelations; drivers of change such as laws, policies and institutions; management of issues and technologies related to water supply; institutional set-up; economic instruments such as pricing, taxes, subsidies; and economics of ecosystem services are crucial. Climate changes, melting of glaciers and polar ice caps, rising sea level and the increased frequency of extreme events, have to be factored into integrated management of water resources. This book addresses some of these major issues related to aquatic ecosystems and focuses on three major aspects: (a) concepts related to ecosystems, ecosystem services and their linkages with water; (b) human impacts on ecosystems, particularly the aquatic ecosystems, and their assessment; and (c) the management, including policy, governance and economics. Comprising new theories, research and case studies, the book will be useful those concerned with water resource management ” professionals, students and researchers.