Performance Evaluation of Ameleke and Halo-Gelana Small Scale Irrigation Schemes located in Gedeb and Wonago Woredas Gedeo Zone Southern Nations, Nationalities and people Region, Ethiopia

Abstract

This study was conducted to evaluate the performance of Ameleke and Halo Gelana small scale irrigation schemes at Gedeo Zone, southern Ethiopia with command area of 42 ha and 75ha respectively. To achieve the objective primary and secondary data were collected. Ameleke and Halo Gelana irrigation schemes were compared using internal and external performance indicators. In order to evaluate the irrigation water use efficiency of farmers at field level, nine farmer fields were selected from each irrigation schemes in relation to their location (from the head, middle and tail end water users). The internal process indicators which include conveyance, application, storage, deep percolation ratio and overall irrigation efficiency were used to check the internal performance of the two irrigation schemes. From the analyses of the internal performance indicators, the mean conveyance efficiencies per 100m length at main canal were found to be 93.3 and 78% and application efficiencies were found to be 72.13 and 67.55% for Ameleke and Halo Gelana, respectively. The runoff ratio for both schemes was nil as the furrows are closed end type. Deep percolation ratios in the same order of the schemes were found to 28.20 and 32.45% for Ameleke and Halo Gelana. Storage efficiencies of 77.35 and 80.7% were also found for Ameleke and Halo Gelana irrigation schemes, respectively. From the analysis of external indicators, the outputs per cropped area were found as 2,852.77 and 2,179.41 US$ ha-1 for Ameleke and Halo Gelana irrigation schemes respectively, but the value of the outputs per command area of schemes were 2,852.77 and 1,278.59 US$ ha-1 for Ameleke and Halo Gelana irrigation schemes respectively. The output per unit irrigation supply of Ameleke is 0.17 and that of Halo Gelana is 0.13 US$ m-3 . Output per water consumed was 0.18 and 0.14 US$ m-3 for Ameleke and Halo Gelana irrigation schemes respectively. The water use performance of the two schemes were compared, relative water supply and relative irrigation supply were found as 1.06 and 1.07 Ameleke and Halo Gelana respectively. The irrigation ratio of Ameleke was found to be 1.00 which means 100% of command area was under irrigation and that of halo Gelana was 0.59 which means about 41% of command area is not under irrigation during study period. In general, based on the assessment carried out, Ameleke irrigation scheme performed better than Halo Gelana scheme. But there is still a room for improvement of the performance of both schemes specially on improving water delivery system, introducing high value crops and agricultural intensification