A thesis submitted in partial fulfillment of the requirements for the degree of Master of Engineering, School of Civil Engineering

Thesis (M. Eng.) - Asian Institute of Technology

Hill Irrigation falls in a class of its own due to its mountain setting and scale. The conveyance systems of Hill Irrigation have to be developed appropriate to its setting and scale. The conveyance systems of Hill Irrigation are dealt in this study more on the practical fieldbased perspective than on theoretical level. The study outlines some of the measures required at the diversion point to control sediment intrusion into the irrigation canals. The factors that should influence the choice of diversion structures is presented. The sediment related problems of hill irrigation system is presented against the background of the wider environmental problems of the mountain watersheds. The study confirms the need for control of sediment at various levels; at the watershed to the scheme level. Prevention and mitigation measures of sediment problems in the form of long and short term solutions are proposed. An attempt is made to compute the water duty of the study area by CROPWAT Programme with the input of more reliable climatic data. The high conveyance losses found by the study on Hill Irrigation confirms the need to upgrade the conveyance structures. The low conveyance efficiency is due to the poor state of the conveyance systems and the poor management of the canals by the beneciaries. The study reveals the need for research on alternative low-cost lining materials. Improvement in the design of some component of the conveyance structures is included as found necessary from the field study. An assessment of the Water Users Association as an organization to carry out O&M of irrigation infrastructure is included. The assessment is centred on the organization's capability mainly in terms of resources and skills. The beneficiaries are constrained by lack of resources and skills for satisfactory management of the irrigation schemes.