Overview
Constructing submerged breakwaters to create perched beaches is a form of mitigation for segments of coastline with steep, eroding beaches. It comprises the construction of one or more underwater sills coupled with sand re-nourishment on the landward side. The underwater structure can reduce wave energy on the beach, leading to a reduction of sand losses and nourishment requirements. The reduced hydrodynamic energy behind the submerged breakwater may yield suitable conditions for sea grass meadows, while the structure itself could provide hard substrate for coral establishment, oyster reefs etcetera.
