PERFORMANCE EVALUATION OF ELLA SMALL-SCALE IRRIGATION SCHEME AT HUMBO DISTRICT IN WOLAITA ZONE, SOUTHERN ETHIOPIA

Abstract

Irrigation could serve as practical solutions to address the difficult of food insecurity by increasing farmed production. This study was conducted to evaluate the performance of Ella small-scale irrigation scheme using some selected performance indicators: Conveyance efficiency, water delivery and physical performance indicators with in the period of October to December, 2022. to achieve this; the primary data collected were discharge measurements, soil samples, infiltration test, group discussions, and semi structured questioner filled. Besides, secondary data were climatic, designed and current irrigated area per one irrigation season. Materials used for data collection were Current meter, Parshall flume; double ring infiltrometer and so on. The soft wares used were GIS 10.7, Excel and CROPWAT 8.0 to analyze the data that had been collected. Based on analyses, Lined & Earthen Main and Earthen secondary canals had averaged conveyance efficiency and losses with values of 83.1%, 76%, 69.58%, and 16.9%, 24%, and 30.42%, respectively. As a result, the scheme was functioning in a "fair" state for delivery efficiency and "poor" state for average values for indicators were found to be delivery efficiency (0.78), adequacy (0.79), equity (0.28), dependability (0.29), deficiency (0.9), and overall performance indicator (0.40), respectively. The average monitoring period results found that Water Surface Elevation Ratio (66%), Sustainability of irrigated area (84%), Irrigation Ratio (70%), Effectiveness of Irrigation infrastructures (66.4%) and Equity ratio for head to tail (1.49) of the canals during the monitoring period were less than standard value. There was an unfair distribution of water due to water scarcity and illegal water users as the beneficiaries responded. Generally, the overall performance of the scheme is poor. Therefore, a gated division system, regular canal clearance, maintenance of broken irrigation infrastructures, proper management approaches, extension and training are needed to ensure long-term sustainability of the scheme. So, all irrigation and drainage domains must work together in order to mitigate the water scarcity of the irrigation system.