Abstract:
Upper Mile Irrigation Scheme is found in Amhara National Regional State, specifically in
Ambasel woreda. Though the scheme has short service years after construction, many
complains were reported by the farmers regarding the operational and management aspects
of the scheme. However, no any assessment was made since its implementation to know the
present status of the scheme. The objective of this study was evaluating the performance of
Upper Mille Irrigation Scheme using the water delivery and water use performance
indicators. Primary and secondary data were collected using standard procedures.
Laboratory analysis, CROPWAT-8 Model, GIS and Excel sheet were the major data analysis
tools employed. The result of the study revealed that, the average conveyance efficiency of the
main, tertiary and field canal system were 88.89%, 69.09% and 51.33%, respectively. The
relative water supply and relative irrigation supply values in the study months were found to
be 1.89 and 1.69, respectively. The average application efficiency, storage efficiency and
overall efficiency of the scheme were also 67.12%, 79.56% and 45.14%, respectively. The
deep percolation loses have an average value of 32.88%. This implies that, the value of most
of these water delivery and water use indicators were below the attainable value suggested by
many researchers. The survey result also shows that, there was no water user association in
the scheme but the water user committee was formed by the users at the village level to
manage the scheme. 53.57 % of the farmers agreed that, the main factor of the water loss in
the scheme was due to the conveyance system. 71.43% were also responded that there was
unfair water distribution to the users. Poor canal alignment, damage of the controlling gates,
unavailability of enough tertiary and field canals, canal breaching by the illegal users,
seepage and illegal diversion were among the causes of water lose and unfair distribution of
water to the users. In case of the irrigation scheduling criteria; 42.86% have used the
symptom of crop leaf welting, 39.29% have used checking of soil moisture near crop roots,
and (17.86%) used both techniques. Based on the result of this study, the overall efficiency of
the scheme was obtained as 45.14% which was nearly equal with the value considered at the
design stage. But, it was the lowest value suggested by Rai et al. (2017) and it needs some
improvement for a better performance.
