Abstract:
Scarcity and misuse of water pose a serious and growing threat to life and sustainable
development. This study was initiated to evaluate the performance of Tabiq small-scale
irrigation scheme found in south Gondar using selected performance indicators. Performance
evaluation focused on determining conveyance, application, storage,deep percolation ratio and
overall efficiencies and the minimum sets of external indicators were used. To achieve the
research objectives, all required data were collected through primary (discharge measurements
in the canals, measurement of irrigation water applied to the field, field observations,
interviewing beneficiary farmers and monitoring soil moisture contents before and after
irrigation, determination of soil physical properties) and secondary (meteorological data,
design data, published and unpublished documents), This study was conducted for one
irrigation season (January-May). The collected data were analyzed using empirical equations
and statistical analysis in percentagebasis. The average conveyance efficiencies were 88.84%,
85.53%, and 81.9% for lined main canal, secondary-1 and secondary-2 of the scheme
respectively. The application of Head, Middle and Downstream were found to be 60.65%,
64.30% and 74.70% respectively.The average storage efficiency for all fields was 66.86% and
the over all efficiency was 59.11%. Output per unit irrigated area and outputs per unit command
area were found to be 1997.45 US$ per ha and US$ 1043.88 per ha respectively. Output per
unit water supplied and Output per unit water delivered values were US$0.19 per m
3
and
US$0.38 per m
3
respectively. The irrigation ratio was found to be 73% which means 27% of
command area was not irrigated during the study period. The ratios of relative water supply
and the relative irrigation supply were 1 and 0.9 respectively. Based on the assessment of
farmer’s perception about the performance of the scheme, the respondents believe that major
problems were non-reliability of the water sources, poor water management, illegal water users
,water scarcity and water allocation conflict of the scheme. In conclusion, the overall
performance of the scheme is rated as low. Therefore it is suggested that proper institutional
setup, frequent maintenance, proper water delivery plan, scheme monitoring and upgrading
needs to be in place and the Water User Assosion should be empowered in order to discharge
its responsibility are required to mitigate these problems.
Keywords: Evaluation, Performances, indicator, Tabiq