PERFORMANCE EVALUATION OF TSILWE SMALL SCALE IRRIGATION SCHEME IN GABA CATCHMENT ENDERTA DISTRICT, TIGRAY REGION

Abstract

This research (study) was conducted to evaluate the performance of Tsilwe SSIS in Enderta district, Tigray Regional State, Ethiopia. The performance of Tsilwe SSIS was not appraised since its operation. Therefore, this study was carried out to evaluate the performance of Tsilwe SSIS using Internal and external performance indicators. This study used primary and secondary data for assessing the irrigation performance. The primary data collected includes field observation, soil samples to characterize the soil in terms of physical characteristics and discharge measurement at main and field canals. Secondary data collected were total yield, area irrigated, crop type, and climate data. CROPWAT 8.0 model was used to calculate ETo and the crop water requirement. The analysis of internal performance indicators showed that the conveyance, application, storage, overall irrigation efficiencies and distribution uniformity were calculated and the results were 93.5%, 71.1 %, 60.2 %, 66.6 % and 87.2 % respectively. The analysis of water related indicators such as RWS and RIS were found to be 0.88 and 0.85 respectively. Since value of RWS and RIS is less than one this indicated that the total water supply is not enough to meet the crop demand and the WDC for Tsilwe irrigation system was calculated as 0.7, since this is less than unit that indicates the canal capacity is insufficient to get the peak consumptive requirement. Agricultural related indicators such as output per unit irrigated area is 153958.6 birr/ha and the output per unit command area is 95860.99 birr/ha. Water productivity indicators such as, Output per unit water consumed and Output per unit irrigation water supplied are 42.2 birr/m3 and 1.83 birr/m3 in TSSI scheme respectively. Based on the results obtained can be concluded that the water related indicators results were below the standard while the agriculture production indicators are found to be reasonable