A simple model for the interaction potential of water with a solid surface is proposed. Adsorption energy, surface structure, corrugation, and the orientational anisotropy of the interaction can be varied. The model is used to determine the dependence of the water/metal interfacial structure as a function of the adsorption energy. Adsorption of an iodide ion from the solution onto the surface is studied for two different water adsorption energies. The results confirm the interpretations of previous simulations, namely that the repulsive solvent contribution to the free energy of iodide adsorption is mostly due to the steric displacement of adsorbed water molecules.