Water use optimization of Benel Reservoir in Jembrana Regency, Bali Province

Abstract

Benel Reservoir has a storage capacity of 1.71 million cubic meters (MCM) and has been supplying water for irrigation purposes. In line with population growth, the Benel Reservoir is projected to be capable of meeting the domestic water demand in the Jembrana Regency. As a result, this research aimed to determine the optimal water use in the Benel Reservoir for irrigation and domestic uses. The irrigation water requirements are necessary for an area of 1,047.3 hectares, while the domestic water demands are 64 l/s. F.J Mock Method of rainfall-runoff model is used to calculate water availability using 10 years of daily rainfall data and has been calibrated using observed discharged data from the Benel water level gauge station. The optimization model is formulated using linear programming. During wet years, the optimization result for water utilization with inflow discharge yields a cropping intensity value of 300%. The cropping intensity value of 287.50% in the scenario of normal inflow discharge. Furthermore, the cropping intensity value is 275% in the case of dry-year inflow discharge. Irrigation and domestic water demand met the minimum value limit of 0.70 and 0.85 for the k-factor. The reliability in supplying irrigation and domestic water reached 100%.