the barrier proposed by the invention consists of gate elements or components which move on inclined planes , characterized by the fact that in the rest position on the edge of the waterway , preferably on the shore , the gate elements or components can be inserted inside one another in telescope fashion . with suitable lengths of the foundations forming the inclined planes , the gate elements which can be moved in tracks independently of one another can be removed completely from the water and pushed together above the average high water level . the cross section of the gate elements has a triangular shape , whereby the ocean - side supports the dam wall and the inland side primarily absorbs the bracing forces .