Shore protection with beach islands

Beach islands and steep beach profiles have been applied as part of the shore protection schemes at a number of unique waterfront developments designed by COWI. Beach islands are circular shore protection structures placed along the beach to reduce the littoral drift and orient the beach towards the dominant wave direction. The effect of the beach islands can be increased by increasing the diameter of the island and by adding groyne type structures at the seaward and landward side. Beach islands add to the recreational value of the waterfront development by providing a dry platform between the sea and the beach suitable for a wide range of recreational purposes.

Sometimes man-made beaches shall be constructed in deeper water as in the case of new islands. Feasible beaches can be constructed in deeper water depending on the local wave conditions. In some cases the wave climate is mild, forming a narrow littoral zone. Then the natural equilibrium beach profile may develop leading to a steep outer slope. It should be noted that significant wave impact is required to provide a clean beach of high quality. When the wave exposure is larger a reef type structure may be needed in deeper water to support the beach profile and thereby reduce the extent of the littoral zone to reduce construction cost.

The background and considerations for development of shore protection schemes including beach islands and steep beach profiles are presented forming an overview of the possibilities for applications of such features into modern waterfront developments.