We consider the Saint Venant’s equations applied to flood routing in rectangular open channels. The model is solved numerically using a finite volume method on staggered grids. We select the use of this method, because Riemann solutions are not needed so that the numerical calculation does not require a lot of efforts and the numerical computation is cheap to do. Simulation results indicate that our proposed method is successful in solving the problems. In addition, we obtain that the greater value of the friction leads to the smaller value of the discharge.

Saint Venant’s equations, flood routing, finite volume method.