Managed Realignment (also called Managed Retreat or De-Embankment in Europe) involves deliberately breaching, or removing, seawalls to allow tidal waters from adjacent coasts or estuaries onto the land.
Depending upon the height and shape of the hinterland, there may be a need for a new sea defence line behind the site. As the newly flooded land is often low-lying coastal floodplain then such a new seawall/'counterwall' is usually required. However, on areas with rising ground no major new defence is necessarily needed. In some cases, the overall land-form can also be lowered or raised to manage the new tidal flows.
Managed Realignment can be used to create a range of habitats including mudflats, saltmarsh, brackish grazing marsh and saline lagoons.