This encyclopaedia provides a comprehensive and integrated examination of groundwater and sustainable water resources management, with emphasis on planning, design, and effective implementation. It explores the growing pressures on global water systems arising from climate variability, population growth, urban expansion, and changing land use. The book examines scientific, technical, legal, and policy-based approaches to managing surface and subsurface water resources across local, regional, and transboundary contexts.

The discussion addresses watershed-based management, water quality protection, allocation mechanisms, and governance frameworks that shape access, equity, and sustainability. Attention is given to policy reform, legal instruments, and international cooperation in addressing scarcity, conflict, and competing demands for water. The book also considers urban and basin-scale challenges, highlighting strategies for regeneration, conservation, stormwater management, and efficient use of limited resources. By integrating hydrological science with institutional and regulatory perspectives, the encyclopaedia offers a balanced and practical understanding of contemporary water management challenges. It serves as a valuable reference for students, researchers, planners, engineers, policymakers, and professionals engaged in sustainable water resources management worldwide.