Abstract:
Assessment of large-scale irrigation performance and its economic contribution is one of
the key factors for the sustainability of large irrigated agricultures. This paper, focuses on
Saudi Star Agricultural Development Project, a large irrigation scheme holding 10,000ha
of land in western Ethiopia of Gambella’s Abobo woreda. The scheme has not been
assessed since its commencement. Therefore, this paper is the first in its kind to identify the
on-farm performance management gaps of the large scheme and its economic contribution
to local community at Abobo. Many indicators were developed for the assessment of
scheme performance. Among few evaluated at Saudi Star farm were; internal indicators
such as conveyance efficiency and application efficiency, where as external indicators
evaluated were agricultural productivity indicators, water supply indicators and physical
indicatiors. In this study, the production outputs of the irrigated area were obtained in
terms of gross or net value of production measured at local and international prices. As a
result of the scheme analysis, the agricultural productivity of the scheme production’s
output per unit irrigated area (OPUIA), output per unit command area (OPUCA), output
per unit irrigation supply (OPUIS) and output per unit water consumed (OPUWC) were
determined as 2,099.50 US$/ha, 4,087.46 US$/ha, 0.99 US$/𝑚3 and 0.40 US$/𝑚3
respectively. The calculated water supply indicators were 1.32 for relative water supply
(RWS) and 0.99 for relative irrigation supply (RIS). The computed physical indicators were
0.85 for irrigation ratio and 0.82 for sustainability of irrigated agriculture. The mean
conveyance efficiency of the main canal was 81.1% and that of secondary canals was
computed as 67.5%. The canal losses were 5.61 l/s/100m and 6.88 l/s/100m at the main
and secondary canals respectively, with 52% of application efficiency at the scheme. The
high water holding capacity of clay soil indicated that the scheme has improving
application efficiency. The low output production of Saudi Star large farm was triggered
by the low value crops grown in the scheme. The high water loss revealed that, overall,
maintenance and repair work on the conveyance canals were not sufficient. Moreover, the
analysis of socio-economic benefits of the scheme to the local community at Abobo revealed
that technology transfer and employment opportunity were nearly met, but contrary to
market and infrastructural development.
