The authors carried out measurements about the volume of water supply loads and the consumed amount of electric power by booster pump system in a super high-rise apartment house. Based on the results of measurements, the trend of fluctuation of water consumption and electric power were analyzed. As for the estimation of suitable water supply loads, we applied the Monte Carlo simulation technique. In comparison with the results of simulation and the measurement data, Lie clarified that it was possible to estimate the volume of water supply loads by using the simulation method and suitable parameters.