Lining of irrigation canals during operation is always a major problem facing the operators of irrigation networks. The same problem has been faced in some of the Iranin irrigation networks, including Moghan project, where rising of ground water table and consequently water logging has been observed. To solve the Problem , several methods for lining of the canals during operation were proposed and finaly -use of geotexile concrete matters was favored for this purpose. A section of Moghan main canal of 840 m.lenght was chosen and lining operation was commenced in summer of 1996, when the canal was in use .Lining was made of thin sheets of woven geotextile , having 5m. Width and infinite length. which have been grouted by workable concrete when placed under water. The thickness of the concrete mattress was 10 cm. after setting of concrete. This paper presents the technical specifications of the material, its final shape and behavior as well as the costs of the project.The rate of seepage, effects of uplift under the lining and durability of the material have been also investigated. The results of investigation showed that after a 6 months period of operation, lining had been in a good condition and its performance was evaluated as perfect. If the geotextile sheets can be produced in the country, this type of lining is economically and technically recommendable.
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