|Seasonal rainfall at the source of the Bafing River in Guinea has historically led to seasonal flooding along the Senegal River, which receives over half of its flow from the Bafing. Prior to the 1970s, this pattern of inundation provided the basis for flood recession agriculture that supported hundreds of thousands of people.|
Drought in the 1970s, however, spurred the formation of the multinational Organization for the Development of the Senegal River (OMVS) to develop irrigation, power generation, and navigation. The Manantali Dam in western Mali was one of two large dams built as part of the OMVS project. These images show the vast extent of land inundated by the filling of the dam's reservoir. Roughly 10 000 to 11 000 thousand people were displaced above the dam.
Below the dam, loss of the normal annual cycle of flood and recession reduced traditional agriculture substantially. Village-scale irrigation schemes have had limited capital for equipment and have been constructed without adequate drainage, resulting in soil salinisation. Flood recession farming was shown to give small farmers a better return with less risk than irrigated rice. Reduced flooding may also be contributing to deforestation along the Senegal River. The Manantali Dam did not produce any hydroelectric power until 13 years after its completion, and only after additional money was provided by the World Bank and others. View detailed information