SEEPAGE AND LEAKAGE LOSSES FROM EARTHEN CANAL AT METEHARA SUGAR ESTATE CORPORATION, EAST OROMIA, ETHIOPIA

Abstract

Irrigated agriculture makes major contribution to food security, providing nearly 40% of agricultural food production from the 17% of agricultural land of the world. The estimated water seepage loss varied from 20% to 40%. This study was conducted to determine water losses for earthen canals at Metehara Sugar Estate Corporation. Water loss due to seepage and leakage in the canals was measured using observation wells and inflow-outflow method. The physical and chemical properties of soil near the canals were analyzed.The canal bed slopes were surveyed using Sokia B-20 leveling instrument. The bed slopes of canals were 0.076%, 0.088%, 0.091% for main, secondary, and tertiary canals respectively. This study was presents preliminary findings on seepage loss estimated by observation wells and and leakage loss using inflow-outflow method governed by Indian Council of Agricultural Research and United State Bureau of Reclamation. The average seepage loss measured using observation wells were 1.77x10-7 to 1.27x10-6 m3 /sec/m2 , 4.31x10-7 to 1.19x10-6 m3 /sec/m2 and 3.53x10-9 to 4.24x10-7

m3 /sec/m2 at main, secondary, and tertiary canals, respectively. The leakage losses measured by inflow-outflow method values varied from 0.06 to 0.16 m3 /sec, 0.047 to 0.091 m3 /sec and 0.024 to 0.036 m3 /sec for main, secondary and tertiary canals, respectively. The seepage loss measured by observation well from earthen canals closely related the Bureau of Indian Standards (1980) of unlined canal varies from 0.3 to 7.0 m3 /s per 106 m2 of wetted surface. Generally, the values of the losses were due to canal condition and water management systems. It is, therefore, recommended that the canals must be lined and canal structures need to be rehabilitated.