Impacts of management and modernization on water savings in large irrigation systems

Impacts of management and modernization on water savings in large irrigation systems By: Lanie A. Alejo, Orlando F. Balderama Key Words: Large irrigation system, Optimization, OASIS model J. Bio. Env. Sci. 18(5), 35-42, May 2021. Journal Name: Journal of Biodiversity and Environmental Sciences Abstract This study was conducted to assess and optimize the conveyance performance of major irrigation systems in the case of the NIA-Magat River Integrated Irrigation System in the Philippines. Options Analysis in Irrigation System (OASIS) was used to evaluate and optimize the conveyance efficiency of the system. Management and modernization scenarios were undertaken in the irrigation system assuming that the rehabilitation projects exerted efforts on improving efficiencies and reduced losses in the conveyance and distribution systems. Based on the results, the actual condition of the irrigation system as the reference of improvement will have 1,365,759 million cubic meters diversion supply from MARIIS and Baligatan diversion dams. Having been improved from 76% of conveyance efficiency to 95% assumed result of the improvement measures, approximately 84,303 million cubic meters or 6% increase from the actual diversion requirement can be realized. With every 1% increase in conveyance efficiency, there will be approximately 33,831 cubic meters savings in irrigation diversion requirements. This could be achieved through canal repairs of damaged structures, the lining of earth canals, and modernization of control structures. The OASIS program has shown its ability to assess the effects of irrigation management and modernization in a large irrigation system that can serve as a science-based planning and decision-making support program. It may also be used to study the management and optimization of irrigation in other irrigation systems in the country and elsewhere in the world