Flood stoppers are structures built to prevent flooding. Dikes (5 letters) are walls made of earth or stone that are built to hold back water. DAMS (4 letters) are barriers built across rivers or streams to control the flow of water. LEVEES (6 letters) are embankments built along rivers and streams to protect against flooding. All three of these structures are used to help prevent flooding and are collectively referred to as flood stoppers.