A dam is a barrier built across a stream or river to stop or check the flow of water. Generally done to capture water for human irrigation, flood control or to generate elecrical power. The most important load that a dam must be able to support is the water behind it. How much the water pushes on the dam is called water pressure. A dam s shape can help it to withstand the pressure.
Water pressure increases with the depth of the water.
A dam s design must enable it to withstand greater pressure at the bottom than at the top. As a result, many dams are built in a triangular shape. The wide bottom withstands the great load of the water deep below the surface, while the top of the dam can be built thinner so as not to use unnecessary costly materials. There are different types of dams based on what materials used, and dam design. The factors in determining the type of dam built include the size, foundation conditions, temperature, pressure changes, water analysis, and location.