| Dams are large concrete structures that are built across the middle of rivers. Their purpose is to hold back water, which often creates a lake behind the dam. They also control the flow of the river and produce electricity. Dams can be beneficial because they can provide a stable source of water. This water can be used for farming, for drinking, and even as a habitat for fish and other animals. Additionally, machines are built into the dam that generate power. This power is created when the force of the water moves through the dam, causing a turbine to spin and create an electric current. On the other hand, dams can cause problems for people who live behind them. Because a dam causes a river to swell and create a lake, anyone living near the river will have to relocate. Entire villages have had to be moved because of this reason. |