IS LARGE-SCALE PUBLIC IRRIGATION THE WAYFORWARD FOR SUB-SAHARAN AFRICA? - Sustainable Irrigation Development in the White Volta Sub-Basin - page 75

subsequent chapters. A comparative analysis of large and small scale
technologies will help draw meaningful conclusions on the way forward for
upscaling irrigation development in sub-Saharan Africa.
4.2 L ARGE -S CALE I RRIGATION D EVELOPMENT IN
SUB -S AHARAN A FRICA
The semi-arid and savannah regions of sub-Saharan Africa have little choice
but to practise irrigated agriculture to support their dependent population.
Basically, these consist of the Sahel countries of West Africa, the drier
portions of northeast Africa and the broader lands of the Kalahari Desert in
Southern Africa. The Sahel is a zone demarcated roughly by the rainfall
isohyets of 100mm/a in the north and between 500 and 600mm/a in the
south with less than 100days for growing crops under rainfed conditions. In
the savannah zone the mean annual rainfall is between 880 and 1200mm/a,
with between 120 and 240 days for growing crops (FAO, 1986; Rosegrant and
Perez, 1997). The success of irrigated agriculture is seen as a key ingredient
for the long-run development of Africa's semi-arid lands. African leaders in
these regions saw that further attention to irrigation development was
unavoidable (Moris and Thom, 1990).
Irrigation has however, remained limited in most sub-Saharan countries; with
a few large commercial schemes developed during and after the colonial
period and a relatively modest small-scale irrigation sub-sector (FAO, 2005).
Among the colonial large scale irrigation projects are the Office du Niger
project of Mali, the Gezira scheme of Sudan, Loumbila scheme of Burkina
Faso and Jebel Aulia (Jabal Awliya) scheme of Sudan.
Sub-Saharan Africa has benefitted from the development of large-scale
irrigation schemes during the post-colonial era with projects developed by
governments and international agencies. These include: the Bakel Project of
Senegal, the Bakolori Irrigation Project of Nigeria, the Bura West scheme of
Kenya, the Lery scheme of Burkina Faso and Manyuchi II scheme of
Zimbabwe.
Semry I and II irrigation schemes in Cameroon are considered as some of the
few success stories of large-scale irrigation schemes in sub-Saharan Africa.
Semry I and II have had estimated rates of return above 20 percent/a under
highly centralized management regimes. Management of water, agronomic
decisions, and cost recovery were handled by project management rather
than farmers and high financial returns were maintained for the farmers,
ensuring their continued participation and support. Brown and Nooter