Clearly, irrigation can and should play an important role in raising and stabilizing food production, especially in the less-developed parts of Africa south of the Sahara. There are, however, many obstacles to the rapid development of irrigation there.

Large parts of the region have only limited freshwater resources. In other areas, potential resources are insufficiently known to permit reliable planning. Even where water resources are definitely known to be substantial, other conditions may not be conducive to irrigation development. Such conditions may include unfavourable topography and soils, distant markets and inadequate infrastructure, as well as lack of credit, labour, information and other services to farmers.

These problems, while real, do not entirely explain the historical failure to develop the full irrigation potential of sub-Saharan Africa. The data available on that potential suggest that it is considerable. By some estimates it may be as great as 30 million hectares, whereas other estimates project less than 10 million hectares. A reasonable figure may be in the order of 15 to 20 million hectares which, if fully developed and properly managed, could contribute significantly to the food security of the African continent. The fact that some earlier efforts at irrigation development produced disappointing results may be more the consequence of flaws in approach and implementation than of truly insurmountable obstacles. The time is ripe for a new approach.

Irrigation is the supply of water to agricultural crops by artificial means, designed to permit farming in arid regions and to offset drought in semi-arid regions. Even in areas where total seasonal rainfall is adequate on average, it may be poorly distributed during the year and variable from year to year. Where traditional rain-fed farming is a high-risk enterprise, irrigation can help to ensure stable production.