Abstract:
Comparative performance evaluation of irrigation schemes is a tool to establish
benchmarks for both land and water productivity, and to identify performance gaps and
improvement options. Therefore, the aim of this study was to evaluate and compare the
performance of Koftu and Fultino community managed small-scale irrigation schemes
using comparative performance indicators. For this purpose, relevant data were
collected from the schemes from February to April 2017. The primary data were
collected by observations, household survey, discussion and flow measurements, whereas
the secondary data were collected from secondary sources. After the data were collected,
CROPWAT 8.0 computer model was used to calculate the crop water and irrigation
requirements. Then, the schemes were evaluated using four groups of comparative
indicators such as water supply, physical, outputs and financial indicators. The results
obtained showed that the values of relative water supply and irrigation supply were 2.64
and 2.72 for Koftu scheme, whereas 3.32 and 3.52 for the Fultino scheme, respectively.
These values showed that both schemes withdraw more water than demanded. In
addition, the water delivery performance ratio values for both schemes were found to be
high. Physical indicators such as irrigation ratio and sustainability of the irrigated area
showed that 0.9 and 1.5 for Koftu Scheme, 0.61 and 0.8 for Fultino scheme, respectively.
Likewise, the values of the output per unit command area were 5,765.57 and 3,925.42
US$/ha, similarly the output per unit harvested area was 3,714.93 and 3,545.81 US$/ha
for Koftu and Fultino scheme, respectively. The output per unit water consumed and unit
water supply were 0.77 and 0.72 US$/m3
, and 0.23 and 0.1 US$/m3
for Koftu and Fultino
scheme, respectively. The financial self-sufficiency of the both schemes were higher due
to small values spent on operation and maintenance works. According to these results, it
can be concluded that by both land and water productivity the performance of Koftu
scheme was better. While the poor water productivity at Fultino scheme is due to excess
water supplied at the head. At the end, the following ideas were recommended: the water
available at the head of the system could be used to irrigate more land if enough
technical supports and training on distribution and irrigation scheduling should be applied and all canals should be maintained on a regular basis.
