It has long been recognized that groundwater plays a central role in the development of human societies. Groundwater resources arereadily and reliably available compared with surface water resources. In many contexts, the presence of groundwaterensures the presence of life itself.The XXXII IAH (International Association of Hydrogeologists) and VI ALHSUD (Latin-American Association of Groundwater Hydrology for Development) Congress on Groundwater and Human Development, heldin 2002, in Mar del Plata (Argentina),brought togetherover 400 participants from more than 40 countries. Thislively gathering of water enthusiastsexchanged experiences of both fieldwork andresearch. Topics under discussion and scrutinyincluded: Groundwater and Quality of Life; Groundwater in Urban, Suburban and Rural Systems; Transboundary Aquifers; Hydrogeology of Large Plains; Coastal Aquifers; Methods for Groundwater Studies; and Educationabout Groundwater and Groundwater Management. This book contains selected papers, plenary lectures and material from workshops, illustrating the contribution of modern hydrogeology to sustaining humanity'sthirst for fresh and safe water.