Irrigation & Drainage Systems Engineering

Abstract

Eshetu Bekele*, Tena Alamirew

Extensive effort and huge investment towards irrigation development is being made in Ethiopia. However, little or no attention is given to the monitoring and evaluation of the performance of already established irrigation systems. Consequently, many of the existing irrigation systems are deteriorating in their physical structures, operation and management. Hence, this study attempted to evaluate the performance of water delivery performance and dependability of irrigation interval in Tendaho sugar estate irrigation system in the lower Awash River Valley. Water delivered to canals was measured using flow measuring structure and duration of water delivery while actual irrigation interval was monitored for selected fields. The average values of Delivery Performance Ratio were resulted in 0.36, 0.53, 0.54 and 0.38 for main, primary, secondary and tertiary canals, respectively, and the average value of dependability of irrigation interval was resulted in 1.6 for selected fields. These results of both delivery performance ratios and dependability of irrigation interval reveal that reliability of water delivery during study time was rated under very poor, and the fields waited for long time to get irrigation water. To alleviate the problem and avoid water shortage during dry period, Gate of the Dam should be installed; off-taking canals head and cross regulators must be installed for all canals; regularly repair and calibration should be done for all existing regulators in the Sugar Estate.