Wave wall

A wave wall is the upstanding parapet, often recurved, on the crest of a breakwater, sea wall, or revetment that deflects up-rushing water seaward to cut overtopping. It lets a structure meet an overtopping limit with a lower main crest, saving fill, but it concentrates wave impact loads on the parapet and the load can lift or rotate it if the toe and anchorage are under-designed. EurOtop gives the overtopping reduction for a given recurve geometry and freeboard. A bullnose or Stevenson-type recurve returns the jet most effectively when the crest is well above the still-water level.