Shoreline engineering projects (along the coastline or rivers) which are aiming at reducing flood risk, commonly only take into account the space on the water side of the dike, whereas the area on the land side of the dikes is left untouched. This approach has led to relatively abrupt transitions between water and land, instead of the more gradual transitions in natural shoreline zones. As a result of the loss of these valuable shoreline zones, many ecosystems have been lost or are in a degraded state.

Part of the solutions for reducing flood risk and creating a sustainable resilient shoreline could be found inland. Although many of these areas are intensively used and leave little room for ecosystem restoration, there are areas that show potential to integrate wetland development to flood risk management. In many subsided areas behind the dikes, for instance, artificial drainage draws up saline groundwater, whence the yield of agriculture becomes marginal and drainage becomes too expensive.

Moreover, in the province of Zeeland, the Netherlands, the successive stages of land reclamation have resulted in areas bounded by a primary dike and an older secondary dike. In these so called “Inlagen” or coastal buffer zones, profitable agriculture has become unfeasible. By connecting these inland areas with the water system outside the primary dikes, a broader coastal zone with a low salinity gradient is created, which can take over part of the ecological functions of a natural coastal zone. Depending on the other functions in the area (e.g. housing, recreation, aquaculture), the connection with the outside water can consist of pipes, dikes that are spilled over during storms, or openings in the outer dike. The new areas can be combined with other functions such as housing, recreation or aquaculture.