Assessing and Improving Water Productivity of Irrigated Rice Systems in Africa

(eds M.C.S. Wopereis et al.) 265 supply sufficient water for drinking water and irrigation. Exceptions are the Volta River basin in West Africa and the Orange and Limpopo River basins in Southern Africa, where population density and large-scale irrigation systems put great strains on water resources availability (Ravenga et al., 2000). There is large untapped irrigation potential in SSA. IFPRI (2010) estimates that the largest potential for smalland large-scale irrigation systems is in Nigeria (5.7 million ha). For SSA as a whole, this potential amounts to 21 million ha, of which the Gulf of Guinea sub-region has almost 50% (10 million ha). However, efforts to manage water and to make it available (e.g. for agriculture) are hindered by the undeveloped state of institutions in terms of low levels of expertise, knowledge and capacity to develop and manage irrigation, and by the prevalence of subsistence farming. Other challenges for development are related to the absence of an adequate policy and strategic framework, the often disappointing results of previous irrigation development, the need for continued support to cover recurrent costs from the public sector, and the relatively high costs of conventional irrigation development (IFPRI, 2010). The agricultural sector faces increased competition from other users, such as the industrial Introduction