River embankments are structures built along the banks of rivers to protect against flooding. LEVEES, which are 6 letters long, are earthen walls that are built up to contain the river's water and prevent flooding. Dikes, which are 5 letters long, are similar to LEVEES but are made of stone or concrete and are used to protect against high tides and storm surges. Both LEVEES and dikes are important components of river embankment systems.