Hydraulic and economic performance of hydro-flume Irrigation at metahara sugar plantation, oromiya Region, ethiopia

Abstract

Any modest improvement in the performance of irrigation water management for thirsty sugarcane schemes management has substantial impact. One way this can be achieved is through a systematic evaluation of the performance of existing schemes in order to take action towards improving the technical, environmental and economic health of the system. This is specifically true with the introduction of new water conveyance system such as hydro flume. This study was initiated to investigate performance of Metahara Sugar Estate irrigation system in terms of hydraulic and economic performance indicators. The performance indicators used to evaluate the irrigation schemes are oriented towards the variables that directly or indirectly affect water deliveries and water spreading effects. The evaluation was made using seven technical performance indices such as conveyance efficiency, application efficiency, water storage efficiency, water distribution uniformity, deep percolation fraction, runoff ratio, sustainability, sugarcane performance as a function of water application and cost-benefit comparison of open earthen ditch (feeder ditch) with hydro-flume. Crop water requirement based on soil classification and irrigation scheduling of the scheme were also assessed. The technical evaluation was done using three irrigation events on three representative plantations’ fields (from the head, middle and tail end of the command area); whereas the performance of sugarcane as a function of flow rate and cost benefit analyses of hydro- flume was evaluated using sample cane from different variety from different field evaluation was done by laboratory, secondary data was collected from stakeholder. The results indicated that the mean values of discharge were 2.88, 3.45 and 3.45 l/s respectively which is less than the designed discharge of 5 l/s. The field assessment shows that performance of the irrigation scheme is unsatisfactory in terms of conveyance efficiency, application efficiency, deep percolation fraction, run-off ratio and sustainability with mean values of 92.17%, 58.55%, 22.92%, 18.58% and 93%, respectively. However, the distribution uniformity, and water storage efficiency were satisfactory with mean values of 85.42%, and 99.43. The range of cane and sugar yield found in the study was from 9.08 to 13.12 t/ha/month, respectively. Total net cost saving and revenue obtained by implementation of hydro-flume were 1,947,883.64 birr, respectively. As a result, weak operation of irrigation water, poor irrigation water management and poor maintenance of the scheme is seen and its sustainability is uncertain.