ASSESSMENT OF HYDRAULIC PERFORMANCE AND IRRIGATION POTENTIAL OF BILATE TOBACCO DEVELOPMENT IRRIGATION SCHEME

Abstract

The sustainability of irrigation projects, which use extensive open channel conveyance systems to distribute water, depends to a great extent on the ability of the system to economically satisfy farm water needs and to ensure maximum utilization of water commanded for irrigation purposes. This study assess and evaluates the hydraulic performances of the conveyance systems and irrigation potential of Bilate tobacco development irrigation project • in Abaya-Chamo River Basin of southern Ethiopia. The capacities of the existing main · channel and secondary channels are sufficient to irrigate the potential availaole command area. Furthermore, the water balance performance indicators show the possibility of command area expansion. . . The delivery performance ratio is less than unity for all the channels mainly as a result of sediment accumulations. The estimated maximum annual rate of . deposited bed loads and suspended sediment loads entering to the channel system through the main intake from Bilate River are 227.3*10 3 tons/year and 366.6*10 3 tons/year respectively. The total water losses on the conveyance systems are within the permissible ranges. The overall and conveyance efficiencies found to be as per F AO recommendation ranges. Impacts of irrigation water distribution system management, operations and maintenance on the performances of the existing conveyance systems of the irrigation project was tried to be assessed. The overall results of this study can give a clue to the management groups how conveyance systems are performing thereby future planning for improvements of the underperforming components of the conveyance systems can be realized.