Tollesbury Managed Realignment site in Essex, the first large scale attempt at salt marsh restoration in the UK
In the context of coastal erosion, managed retreat (also managed realignment) allows an area that was not previously exposed to flooding by the sea to become flooded by removing coastal protection. This process is usually in low-lying estuarine areas and almost always involves flooding of land that has at some point in the past been claimed from the sea.
In the UK, managed retreat is often a response to sea level rise exacerbated by local subsidence of the land surface due to post-glacial isostatic rebound in the north.
https://en.wikipedia.org/wiki/Managed_retreat
