... further erosion. The sea walls reflects wave energy back towards the sea, this speeds up erosion and deprives the actual beach of sand as the force of the wave undercuts the wall. This sand would have acted as a natural defence to the coastline; its removal leads to further erosion. Wave reflection from sea walls can also lead to a lowering of the foreshore and undermining of the seawall itself leading to actual failure and collapse of the wall over time. Sea walls that have been placed too close to the waterline can disrupt the sediment balance and cause more erosion in down drift stretches of coastline, especially either side of the wall where a reduction in beach width may become evident. For some areas a more effective form of protection may be to build groins. These are less expensive and have been used to great effect in some areas. Groins ...

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