SCHEME LEVEL WATER DISTRIBUTION AND PRODUCTIVITY EVALUATION OF FRE LEKATIT SMALL-SCALE IRRIGATION IN EASTERN ZONE, TIRGAY, ETHIOPIA.

Abstract

This study was conducted in the drought-prone Woreda of Hawzen, Hatset Kebelle, located in the Eastern Zone, Tigray National Regional State, Ethiopia. The research aimed to evaluate the performance of the Fre-lekatit irrigation scheme using selected performance indicators. Specifically, the study assessed the reservoir‘s current water use, irrigation scheme productivity, water distribution, and allocation efficiency. Water applications and velocities were monitored using a Parshall flume, a V-notch weir, and the floating technique at different locations: farm level, secondary canals, and the main canal. A total of 45 measurements were taken at selected points in the head, middle, and tail sections of the command area using a Parshall flume. Soil samples were collected using an auger, while climatic and agronomic data from both primary and secondary sources were analyzed using the CROPWAT model to determine crop water requirements. The findings show that during the 2018 irrigation season over 125 days (January–June), the total amount of water diverted to the field applied and through the main canal were, 56199.4 m3/ha (1,251,516 m3) or 192.2 l/s and respectively. The distribution of water based on the locations of the irrigated land shows that the total volume of water applied per hectare per season for the irrigation scheme was measured to be 8005.7 m3, 7894.4.m3, and 7789.4 m3 for upper, middle, and lower sides of the command area respectively. The WDC ratio value was 1.2, indicating that the system capacity does not constrain the agricultural water demands, whereas the RWS and RIS values were 1.91 and 1.95, respectively. The upper section of the command area received more water compared to the middle and lower sections. To improve water use efficiency and crop yields, it is recommended that farmers receive intensive hands-on training in irrigation management and best farming practices. Additionally, regular maintenance of the weir structure and off-take channels is necessary to minimize seepage and prevent excess water loss downstream.