THESIS ABSTRACT

Abstract

Sustainable irrigation is essential for food security and rural livelihoods in the hilly regions of Nepal, where ageing government-built systems increasingly depend on Water Users’ Associations (WUAs) for operation and maintenance. This study assessed the multidimensional sustainability of the Rampurphant Irrigation System (RIS), a 900-hectare gravity-fed irrigation system in Rampur Municipality, Palpa District, Lumbini Province, Nepal. Sustainability was assessed using four dimensions: Technical, Socio-Environmental, Financial and Institutional, comprising 13 factors and 26 subfactors. From 9,910 beneficiary households, 105 households were selected using Cochran’s formula at a 95% confidence level and 10% margin of error. Data were collected through household surveys, a WUA survey and field observations. In addition, pairwise comparisons from 11 experts were used in the Analytic Hierarchy Process (AHP) to determine the weights of sustainability indicators and calculate the Overall Sustainability Index (OSI). RIS obtained an OSI of 69.60%, slightly below the 70% threshold and was classified as Not Sustained. The Technical dimension scored highest (72.56%), while the Institutional dimension scored lowest (65.89%). A clear head-to-tail performance gap was observed, with head-reach outlets scoring 90.00% compared with 51.88% at tail-reach outlets. The study recommends improving canal infrastructure, water distribution equity, financial management, O&M funding and WUA capacity to enhance the long-term sustainability of RIS.

Keywords

Rampurphant Irrigation System, Multidimensional Sustainability, Analytic Hierarchy Process (AHP), Water Users Association (WUA), Overall Sustainability Index (OSI)