Farmers in Yemen are using earthen canals to convey water into field in different irrigated areas. However, they are reluctant to replace canals with pipes to reduce losses. The main goal of this work is searching for alternatives to help farmers in reducing seepage from earthen canal with low cost. Field work is carried out in 2004, at farm belonging to the Sana’a University. Three parallel earthen canals are constructed, 100 m long each. The canals are designed in similar manner to those used by farmers in traditional irrigation. Many attempts are conducted to find simple methods in lining earthen canal using low density poly ethylene (LDPE) films. As results, several techniques are developed and applied in field, including surface and below surface lining along with partial lining. Both inflow-outflow and Ponding methods are used to estimate seepage from lined and unlined canals. Results of the study shows that the average rate of seepage at the end of first hour of measurements in unlined, partial lining and below surface lined canals are 1.25 ℓ/min/m2, 0.65 ℓ/min/m2, and 0.43 ℓ/min/m2 respectively. At these rates, conveyance efficiencies in canals are 74%, 83% and 93% respectively. Furthermore, the results of measurements at the end of second and third hour have shown further reduction in seepage with different rates. Moreover, the partial lined canals is kept under monitoring until mid of 2006; mainly to examine LDPE’s durability. Nevertheless, the cost of earthen canal lining using LDPE is considered low, but there are variation among techniques.

Key Words :Earthen Canals, Lining Techniques, Poly Ethylene, Low Cost, Reducing Seepage