Is managed realignment a sustainable long-term coastal management approach?

Concerns about sea-level rise and nature conservation led to a shift from hard engineering to more sustainable management approaches. Managed realignment (MR) is increasingly popular in Europe, especially in England where projects often have multiple aims, including: intertidal habitats creation, improved flood risk management and more affordable coastal defences. This article discusses whether MR is a sustainable strategy able to deliver the expected environmental and socio-economic benefits in England. Assessing the sustainability of MR is problematic, as data on projects' performance are scarce, of restricted dissemination and limited in scope and geographic coverage. Additionally, projects lack well-defined targets against which their performance can be evaluated. The few existing independent studies indicate a number of constraints including: reduced biodiversity in small realignment sites; new saltmarsh development at the expense of established habitats: poor ecosystem services provision: and lack of understanding about the effects of MR on hydrodynamic and sedimentary processes. There is little evidence so far that MR in England is achieving its strategic aims. Realignment sites are usually small; confined by new defences and located within or adjacent to designated conservation areas. where conflicts arise as designated freshwater habitats might be destroyed to give place to intertidal habitats. As sea level continues to rise, it is just a matter of time for coastal squeeze to affect the newly created intertidal habitats. Only through a coherent, long-term and national strategy that truly integrates planning. flood management and conservation objectives. MR will be able to deliver the expected benefits.