Optimizing Flood and Sediment Management of Spate Irrigation in Aba’Ala Plains

Floodwater management and sedimentation are the key issues which should be considered during the development of new, or improvement of existing, spate irrigation schemes. The traditional intakes are superior in their site location, flexibility, and sediment-control capability. However, they have been frequently damaged by floods resulting in loss of continuous irrigation supply. The modern structures, albeit strong enough to withstand the impact force of the largest floods, suffer from large sedimentation problems. Farmers of Aba’ala Plain have been struggling with sedimentation and floodwater-management problems associated with their modern and traditional intakes. The objective of this research is, thus, to study the existing flood and sediment management practices and identify alternative options for optimum management of floods and sediments in the Aba’ala Plain, Afar. Aba’ala is the largest plain in the arid lowlands of Ethiopia where a combination of traditional, improved and modern spate irrigation systems are practiced. Extensive fieldwork was undertaken leading to measurement and collection of primary data including discharge, sediments and river cross sections. Interviews and focal group discussions were also employed and these generated deeper insights into O&M activities. In addition