How Dams Are Used For Power Generation And Flood Control

This article discusses how dams are used on rivers for power generation and flood control.

Ever since man has been conscious of his surroundings, he has appreciated and respected the power of water. As he became more technically advanced, the idea of controlling that water for his purposes seemed like a good one. So, he began experimenting with dikes, levees, dams and steam engines. He came to find out that water could produce power, and harnessing that power could control flooding, as well. Dams are the primary means of accomplishing these goals.

According to the Tennessee Valley Authority, hydroelectric power is America's leading source of renewable energy. It is clean, efficient and reliable. Rivers don't simply stop flowing, so hydroelectric power is steady and dependable.

Whether a dam is built more for flood control and power generation, or for navigation as well, the principles of hydroelectric power are similar.



Dams separate a river into two separate levels. The water in the reservoir behind the dam (at the higher level) flows downward through piping into the generator house built into, or nearby the dam. The force of the falling water spins a turbine propeller, which is attached to a generator. The generator also begins to spin, thus creating electricity. The power is then lined out to primary stations and substations, where it is carried to homes and businesses.

Dams also provide the reservoir capacity necessary for operating fossil fuel power plants and nuclear power plants. These plants depend on large quantities of water for the cooling and condensing that keep the generators running.

Most dams also provide flood control, and some are used to facilitate navigation. Dam reservoirs are essentially storage areas that can hold large amounts of rainwater and runoff when heavy rains hit. Dams have a series of gates, called spillways, that provide a tunnel or throughway for water from the full reservoir to be emptied into the river below, at a controlled rate. On a large river, like the Tennessee, the dams work in synch to keep each reservoir level stable, pouring water through the spillways, all the way downriver, as the elevation drops. In this fashion, no one reservoir bears the brunt of heavy rains.

Dams also may help navigation on a river. Again using the Tennessee River as an example, the dams on that waterway help commercial barge traffic, as well as recreational traffic, be able to navigate the river safely. The Shoals area in northwest Alabama is so named because of the sharp rocks close to the surface of the Tennessee River, before TVA built the dams on it. The river was an obvious means of transport, since it empties into the Ohio River in Kentucky, but only experienced riverboat pilots wished to brave the dangers of the Shoals. The construction of Wilson Dam, in Florence, AL, deepened the water, and the locks enabled boats of all sizes to travel the river in safety. Dams also, in their flood control capacity, create a more stable current, good for commercial navigation.

As TVA built more dams on the Tennessee River, and coordinated their operation, the Tennessee River became a major U.S. commercial waterway. Millions and millions of tons of raw materials are shipped by barge each year, reducing the environmental impact of more large trucks on the highways, and saving corporations money. This has been the case nationwide, as dams are built.

Dams truly are miracles of engineering: nature and science working together to create a good outcome, rather than a detrimental one.

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