- Dams are often built along the course of a river in order to control the amount of discharge. Water is held back by the dam and released in a controlled way. This controls flooding.
- Water is usually stored in a reservoir behind the dam. This water can then be used to generate hydroelectric power or for recreation purposes.
- Building a dam can be very expensive.
- Sediment is often trapped behind the wall of the dam, leading to erosion further downstream.
- Settlements and agricultural land may be lost when the river valley is flooded to form a reservoir.
- The river channel may be widened or deepened allowing it to carry more…