Coastal and estuarine marshes have been intensively dyked in Europe, with > 15,000 km2 of poldersa. Climate change scenarios forecast an elevated risk of marine submersion and flood hazards. The cost of dykes management in such hazardous environment justifies an increasing interest towards nature-based (NB) solutions. The restoration of natural flood expansion zones is one of those NB solutions retaining some managers interest. Such restoration can also promote marsh ecological functionalities, that serve many other regulation and cultural services for human societies.