Completion of potential conflicts of interest through optimization of Rukoh reservoir operation in Pidie District, Aceh Province, Indonesia

Abstract

Rukoh Reservoir’s construction was planned to be built in Krueng Rukoh Watershed with supplet ion from Krueng Tiro River. Rukoh Reservoir operating system as a multipurpose reservoir raised potential conflict of interest between raw water and irrigation water. In this study, the operating system of Rukoh Reservoirs was designed to supply raw water in Titeu Sub-District and replenish water shortage in Baro Irrigation Area which is not able to be served by the Keumala Weir. Reservoir operating system should be planned optimally so that utilization of water in accordance with service area demands. Reservoir operation method was analyzed by using optimization technique with nonlinear programming. Optimization of reservoir operation is intended to minimize potential conflicts of interest in the operation. Suppletion discharge from Krueng Tiro River amounted to 46.62%, which was calculated based on ratio of Baro and Tiro irrigation area. However, during dry seasons, water demands could not be fully met, so there was a shortage of water. By considering the rules to minimize potential conflicts of interest between raw water and irrigation water, it would require suppletion from Krueng Tiro amounted to 52.30%. The increment of suppletion volume could minimize conflicts of interest. It produced l00% reservoir reliability for raw water and irrigation demands. Rukoh reservoir could serve raw water demands of Titeu Sub-District and irrigation demands of Baro irrigation area which is covering an area of 6,047 hectars. Reservoir operation guidelines can specify reservoir water release to balance the demands and the target storage.