Artificial water storage of adequate capacity is needed to ensure reliable water supply during droughts and to retain water during periods of flooding. Storage capacity in Africa remains underdeveloped, with average per capita storage standing at about 200 cubic meters per year, a full order of magnitude below countries in other developing regions (see figure).
Water can be put to a wide range of competing economic and environmental uses, and the development of a storage capacity must reflect an awareness of those uses. In the past, irrigation and hydropower were the main drivers for dam construction in Africa, but the trend today is toward multipurpose water storage systems that will result in more-efficient water usage and generate larger economic returns on investments.
Water storage infrastructure need not be large in scale. Small-scale options are also relevant to the achievement of water security and can help the rural poor to cope with water-related shocks to agricultural production. These include off-stream reservoirs, on-farm ponds, networks of small reservoirs, groundwater storage, and storage through a root zone with a variety of water-harvesting techniques.
Water reservoir storage per capita, selected countries, 2003