PERFORMANCE EVALUATION OF SMALL SCALE IRRIGATION SCHEME IN ADDIS-ALEM, SEHARTI SAMRE WOREDA, TIGRAY, ETHIOPIA.

Abstract

Water is scarce and expensive resource which needs to be utilized in a highly productive manner for agriculture. The main objective of this study was to evaluate the performance of the small scale irrigation scheme at Addis-Alem, Seharti Samre Woreda, Tigray Regional State. The importance of performance evaluation of small scale irrigation scheme mainly for advising irrigators on how to improve their system and management practice, intervention across different system levels, and to compute irrigation seasons and technologies The scheme has command area of 60 ha during the current study time and serving about 240 beneficiaries. To achieve the aim primary and secondary data were gathered. The internal and external performances using minimum sets of performance which includes agriculture water use economical, and physical performances. In order to compute the irrigation water use efficiency of farmers at field level, nine farmer fields were identified from the irrigation scheme in the relation to their location (head, middle and tail end water users). The internal process which include conveyance, application, storage, runoff, deep percolation ratio, distribution efficiencies, and overall irrigation efficiency were used to check the performance of the irrigation scheme. The results of the analyses indicate that the conveyance and application efficiencies were found to be 51.297 and 68.07% respectively. The runoff ratio of the scheme was nil as the furrows are block end type. Deep percolation ratio in the same order of the scheme was found to 31.93%. Storage efficiency was also estimated 47.69%. Further, irrigation uniformity of98.91% was attended. From the analysis of external indicators, the output per cropped area and output per command area were found as 4545.455 and 1363.636US$ha-1 respectively. The output per irrigation supply of the scheme was 0.663 US$ m-3 . Output per water consumed in the scheme was 0.974 US$ m-3 . The water use performance of the scheme was computed, water supply and relative irrigation supply were found as 7.362.The irrigation ratio of the scheme was found to be 0.30 which means about 70% of the command area is not under irrigation during the study period. In general,, the performance of Addis-Alem irrigation scheme is low . But there is still a room for improving the performance of the scheme by resizing the main canal as well as the secondary and tertiary canals which were not adequately carrying the required irrigation water