The Changing Coast - Providing Room for Natural Adjustments

Much attention is focussed on protecting built development and infrastructure in coastal areas as a result of climate change and sea-level rise. In some cases, allowance for the coast to adjust naturally to sea-level rise can provide substantial benefits in reduced protection costs and preservation of natural features that underpin the appeal and value of the coast to residents and visitors. Natural foredunes provide substantial protection for inland areas from storm surges. They provide a buffer to reduce the immediate rate of erosion after a severe storm or series of lesser storm events. Given adequate room to form and reform as sea levels change, they provide these services at a minimal cost. Where the natural rate of adjustment may be slow and leave some hind areas at risk, these processes may be assisted by augmentation/nourishment and revegetation undertaken in a way to mimic or reinforce natural processes. All this may be at substantially lower cost than man-made structures of rock, concrete or other responses, and often with greater appeal to many in the community. Some other shoreline types are also prone to flooding, erosion and slumping. In these cases too, provision of an unoccupied buffer zone between the shoreline and development serves as a low cost form of protection from these coastal hazards while also providing a coastal strip giving the social benefit of public access to the shore along with the conservation benefits of retaining a natural coastal reserve. High value coastal ecosystems may also make a claim on space to adjust. Areas that host shore feeding birds, wetlands that provide habitat for migratory birds (RAMSAR sites) and other coastal habitat that host ecological communities such as salt marsh which have declining areas available may have high ecological value. If there were no coastal development, many of these ecosystems could migrate inland with rising sea levels. Where landscape fragmentation due to roads or other forms of development block this inland movement, or where natural landforms prevent this, these natural coastal communities will be lost. Inventories of high value ecosystems that still have potential to move inland are needed, so as to identify priority sites where allowance for inland migration over time can be ensured.