The irrigation water supply system in the Batu Bulan irrigation area uses a conventional system. The conventional method is the provision of water by inundation from the beginning of planting until the fruit ripens. The use of water with conventional systems is very wasteful and inefficient. The irrigation water supply method that can save water use is the System of Rice Intensification method. Calculations are carried out by simulating conventional irrigation water delivery systems and System of Rice Intensification based on crop water requirements, cropping patterns, irrigation area and water availability in Batu Bulan Reservoir. The calculation of inflow discharge scenarios for wet, normal and dry years uses historical discharge data from 1997 to 2022. Based on the simulation results and optimization calculations, different cropping intensities were obtained from the two methods. The percentage of cropping intensity with the conventional method is smaller than with the SRI method. The cropping intensity value for the dry year inflow discharge scenario is 181,85% for the conventional method and 185,82% for the SRI method. The k factor values that have met the maximum value limit for irrigation water and domestic water needs are 0,70 and 0,85. The reliability for each irrigation water and domestic water demand is 100%.