PERFORMANCE EVALUATION OF WAQEMIYA TIYO AND AWASH MELKASA IRRIGATION SCHEMES IN EAST SHEWA ZONE, ETHIOPIA

Abstract

Performance evaluation of irrigation schemes plays a fundamental role in improving irrigation system of scheme by identifying performance gaps that help to provide appropriate improvement options. Therefore, the aim of this study was to evaluate and compare the performance of Waqemiya Tiyo and Awash Melkasa community managed small-scale irrigation schemes located at Adama District, Oromia, Ethiopia using internal and external performance indicators. For this purpose, primary and secondary data were collected from the schemes and for field data measurements three farmers’ fields were selected at the head, middle and tail-end of each scheme. Schemes were evaluated by their own merits with the help of internal performance indicators. Thus, the results of analyses revealed that conveyance, application, storage, overall scheme efficiency and distribution uniformity were 49.0, 56.2, 48.8, 27.5 and 88.2% and at Waqemiya Tiyo whereas, 45.6 53.3, 44.1, 24.3 and 85.8% Awash Melkasa schemes respectively. Then comparison was made using external performance indicators such as water supply, water delivery capacity, outputs and physical indicators. The results obtained revealed that the values of relative water supply and irrigation supply were 0.59 and 0.57 for Waqemiya Tiyo scheme, whereas 0.65 and 0.64 for the Awash Melkasa scheme respectively. Water delivery capacities of Waqemiya Tiyo and Awash Melkasa schemes were 0.60 and 0.37 respectively. The values of output per unit irrigated area were 3962.6 and 2187.3 US$/ha, and similarly the output per unit command area was 4507.4and 2479.US$/ha for two schemes respectively. The output per unit irrigation supply and water consumed were 0.79,0.45US$/m 3 and 0.91,0.57US$/m 3 for two schemes respectively. Likewise, Physical indicators such as irrigation ratio and sustainability of the irrigated area revealed that 1.14, 1.07 and1.11, 1.04 for two schemes, respectively. Based on the results obtained, Awash Melkasa scheme was better in terms of relative water supply and irrigation supply. However, Waqemiya Tiyo scheme had significantly better land and water productivity than Awash Melkasa scheme due to used high value crops, agricultural inputs and removal of grass cover and sedimentation from canal systems. As a result, Waqemiya Tiyo scheme was better performing than Awash Melkasa scheme therefore, practices high value crops, sharing their experience with one another to achieve good performance of the schemes.