STUDY OF THE LOSSES IN AN IRRIGATION SYSTEM - A CASE STUDY

Abstract

The seepage losses in irrigation system (head to outlets), specially with large conveyance system in alluvial plain in India, are quite substantial, nearly 1/3rd of Head discharge. The seepage losses depends upon many factors which vary from system to system. Earlier the irrigation system is considered from head to outlet. But as per Govt. of India, command area development program, the concept of irrigation system is now extended up to water course and field channels. Therefore now watercourses are the ultimate links of conveyance network of irrigation system. The losses on watercourse constitute a major portion of the transit losses, during conveyance of irrigation water from source of farmers field. Hence for getting optimum utilization of valuable water the saving of these losses are essential. The conveyance losses also vary from one element to another in the same system i.e. main canal, Branch canal distributory channel and minor channels. Besides these, substantial losses are also observed below outlet in watercourse and field channel and application of water in fields. They also constitute nearly 1/3rd of supply at the head. The present study would involve the critical review of actual distribution of these losses in different reaches of network i.e. conveyance, distribution and then delivery to field water application in different crops, so that realistic estimation be made of the total losses and suitable reaches in the system be identified for saving the losses, to conserve the valuable resource at economical cost. As a case study, the irrigable command of Upper Ganga Canal is proposed to be use to carry out the critical review of losses observed and estimated from time to time.