It is important from the engineering point of view to predict the collapsing process of river embankment and behavior of overtop flow for reducing disaster during flood. We performed some considerations on refinement of a two-dimensional computational model based on shallow flow equations to predict more accurately the front overflow levee breach phenomena. We tried to introduce a levee erosion model instead of sediment transport model to evaluate the deformation of the levee. In addition, intermittent behavior of the bank collapse is modeled. A calibration of the numerical model is made through the comparison with field experimental data. Recently, a real-scale experiment on a front levee breach was carried out at the Chiyoda Experimental Channel in Hokkaido, Japan. We performed the computation under the same conditions in the experiment. The computational results showed that the present refined model can predict fundamental aspects of the front levee breach phenomena. breach phenomena.