How are dams built?
Engineers use models and computers to figure out how much water a dam will have to support and how big and strong it must be. Then they can decide what sort of dam to design. There are four main types of dams: Embankment dams are the most common type in the United States. They are massive structures made of earth and rock that rely on their heavy weight to resist the force of the water. A layer of clay or concrete may be used to stop leaks through gaps in the rocks. TVA’s Cedar Creek Dam is an embankment dam. Gravity dams are concrete dams that also hold back the water entirely by their own weight. Usually the side of the dam that faces the oncoming water is straight. Most gravity dams are expensive to build because they require so much concrete. TVA’s Norris Dam is a gravity dam. Buttress dams have a series of supports, or buttresses, that brace the dam on the downstream side. Buttress dams may be flat or curved. Most are made of reinforced concrete. There are no buttress dams in the
