Coastal flood risk is projected to increase significantly in the future due to climate change (sea level rise, storm surge) and ongoing land subsidence. In these usually highly urbanized regions, flood defenses are typically hard 'grey' structures such as levees. Levees require regular maintenance and periodic strengthening to meet safety standards. The structural and economic limit of strengthening levees is reaching limits. Instead, more sustainable methods are explored (Nature based Solutions). One of these solutions are tidal marshes. Tidal marshes attenaute waves, reducing levee failure probability, but also reduce flood impact in the event of a levee brach. In order to quantify this secondary effect, levee breach models should include foreshore erosion as well. In this study we performed seven large-scale experiments with and without a foreshore. Our preliminary results show a distinct difference in inflow hydrodynamics which should be considered for modelling efforts.
