In this report, we present the effect of incorporating tidal zones in the idealized, width‐based model iFlow. It appears that incorporating intertidal zones affects the hydrodynamics (i.e. water levels and flow velocities) via four different mechanisms. Each mechanism has been implemented in the two existing solvers of iFlow, the semi‐analytical solver and the numerical solver. An additional solver, the full analytical solver, was created and is applicable to estuary models with a horizontal bottom and an exponentially converging width. It was found that the differences in results between these solvers where overall converging quadratically with increasing grid resolution, emphasizing correct implementation. However, one of the terms, does only converge linearly for a horizontal bottom. In the case of a more realistic bottom, quadratic convergence is still obtained for two of the four terms, while a third term only converges linearly and the fourth term does not converge with increasing grid resolution at all. Although these convergence discrepancies require some additional attention, the error between the terms stays less than 1% giving confidence into the implementation. Overall, the incorporation of intertidal zones was found to have a significant effect on the prediction of the M4 tide. The quantification of this effect has not been realized, mainly because the unrealistic bathymetry used did not allow for a significant analysis. The investigation of the quantitative effect of intertidal zones on the Scheldt is left for a follow up study.