Levees are raised structures built along the edges of rivers or lakes to prevent flooding. They act like walls, holding back water during heavy rain or snowmelt. By keeping water contained, levees help protect nearby homes, farms, and roads from being submerged. These barriers can be made from various materials, including soil, concrete, or rock. In many places, such as New Orleans or the Netherlands, levees are crucial for managing water levels and ensuring safety. However, they require regular maintenance to remain effective, as erosion and wear can weaken their ability to hold back water.