Hydraulic Performance Evaluation of Irrigation and Drainage Infrastructure Serving Ahero Irrigation Scheme in Kenya

The hydraulic performance of irrigation and drainage infrastructure in irrigation schemes in many developing countries like in Ahero Irrigation Scheme in Kenya is poor. The scheme grows rice under irrigation. It is important to evaluate the scheme to come up with measures that will assist the scheme’s managers to better understand the system they control to bring about improvements. The main objective of this research study was to evaluate the hydraulic performance of the irrigation and drainage infrastructure serving Ahero Irrigation Scheme in Kenya. The conveyance efficiency of the earthen main canal and the pumps’ performance efficiencies were researched. The research study employed both quantitative and qualitative research designs. The primary and secondary data types were collected. Specialized software was used in data analysis. The irrigation water conveyance efficiency of the earthen main canal of length 14.3km was measured and found to be 83.2%. The pumps’ average performance efficiency was measured as 47.05%. The conveyance losses along the earthen main canal were caused by the; infiltration losses of irrigation water from the canal’s bed, invasion of aquatic weeds in the canal, and failure of some of the water control structures along the earthen main canal to effectively control irrigation water in the canal. The pumps had low performance efficiencies because the pumps required maintenance and the pumps were at the end of their utility life and were due for replacement. This study recommends; the earthen main canal be lined with impermeable lining preferably by concrete, water control structures be rehabilitated, and the pumps be maintained or replaced with new ones.