In this study is if the design of outlet conduit was appropriate or not by analyzing flow characteristic of outlet conduit with performing hydraulic model experiments. As the results of hydraulic model experiments, the capacity of outlet conduit of elementary design was under estimated, and the designed values of the capacity of outlet conduit of preliminary design based on the values of elementary design was nearly equal to the values of experiments, so the propriety of design was identified. In addition, as the results of examinations of negative pressure of outlet conduit, and propriety of longitudinal sections, the resulting values were within the maximum permissible limits, so it was proved that the design was appropriate. In the base of such processes, the propriety of scale and location of outlet conduit of preliminary design was examined.