Annotation The research presented in this work qualitatively investigates the morphodynamic response of a large tidal inlet/basin system to future relative sea level rise (RSLR) using the state-of-the-art Delft3D numerical model. Understanding the potential impacts of RSLR on these systems is a prerequisite for their sustainable management due to their rich bio-diversity and the increase in economic activities and local communities in recent decades. The adopted approach used a highly schematised model domain analogous to the Ameland inlet in the Dutch Wadden Sea.