In Africa, groundwater is the major source of drinking water and its use for irrigation is predicted to increase substantially to combat growing food insecurity. Despite this, there is little quantitative information on groundwater resources in Africa and groundwater storage is consequently omitted from assessments of freshwater availability. This publication presents the first quantitative continent-wide maps of aquifer storage and potential borehole yields in Africa based on an extensive review of available maps, publications and data. The maps are intended to lead to more realistic assessments of water security and water stress and to promote a more quantitative approach to mapping of groundwater resources at both national and regional levels.