Abstract:
Evaluating performance of irrigation system is essential to safeguard the scarce resource of water by improving performance of existing irrigation schemes. However, there was no study in the past on performance assessment of Damte Irrigation Scheme. The objective of this study was to evaluate the hydraulic performance of the irrigation scheme using hydraulic performance indicators. The study was done during the irrigation season from January to April, 2023. The primary data for this study was measured by using staff gauge, 900 V-notch, GPS and tape meter. The discharge measurement was performed at 12 measuring stations on main canal and field outlet points by using 900 V-notch. Water surface elevation measurement was also conducted along main canal at 13 measuring locations for computing water surface elevation ratio. The physical condition of structures in the scheme was reviewed. The reasons for malfunctioning structures were inspected through field observation. Consistent with the results of the study, the value of adequacy, dependability, equity, equity ratio over head to tail, efficiency and deficiency were found to be 0.77, 0.06, 0.09, 0.90, 1.00 and 0.23 respectively. The values show that water delivery system of the scheme had a poor delivery. The conveyance system was satisfied only 77% out of the total required amount of irrigation water during study period. The overall average value of conveyance efficiency of the 2.4km main canal four was 79.49%. The canal losses were 20.51% of the water. Siltation, structural cracks and vegetation grown within the canal restricts water flow which reduces the conveyance efficiency. The values of water surface elevation ratio, effectiveness infrastructure, delivery duration ratio and sustainability of irrigated areas were found to be 97%, 77.4%, 116.7 % and 82.61% respectively. The results of maintenance indicators showed that the system requires maintenance due to sedimentation of canal, inadequate operation and management of the system. Hence, adequate maintenance and proper management techniques are essential to improve the irrigation system performance.
