Groundwater is Africa's most precious natural resource, providing reliable water supplies for many people. Further development of groundwater resources is fundamental to increasing access to safe water across the continent to meet coverage targets and reduce poverty. There is also an increasing interest in the use of groundwater for irrigated agriculture as the climate becomes more variable. Sustainable development of the resource is not a trivial task and depends crucially on an understanding of the hydrogeology and people with the skills to make informed decisions on how groundwater can best be developed and managed in a sustainable fashion. Despite these obvious needs, however, little attention has been paid to the systematic gathering of information about groundwater resources in the past few decades, with the result that data are patchy, knowledge is limited and investment is poorly targeted. This book was written to start to bridge the knowledge gap. The 29 chapters are written by a combination of practitioners and researchers mainly from within Africa using experience from recent and ongoing projects. The chapters highlight the complexity and variety of issues surrounding the development and management of groundwater resources across Africa, and provide a snapshot of groundwater research and application in the early 21st century. Chapters range from strategic discussions of the role of groundwater in development and poverty reduction, to case studies on techniques used to develop groundwater, and modelling methods for managing groundwater systems.