In this paper have developed a numerical model 2-D hidrodinamic in channel bend, especially at 90. Model based on finite difference solution with explicite Mac Cormack Methode. This research especially study on bed roughness. This model was aplicated on case plume data with nonmovable bed, where topography in steady state. The numerical simulation result is to be comparated with phisical model data. Numerical simulation shown the same distribution velocity trend, however velocity in numeric less then laboratorium data.