Approximately ten percent of energy produced in the United States is from hydropower. In this process, water spins in turbines in generators.

Hydropower is one of the renewable energy sources being researched and implemented to replace fossil fuels, which are in the process of depletion. It does not produce carbon dioxide, as coal power stations do, making it a cleaner, as well as, cheaper alternate way to produce electricity. It is also renewable, with the help of rainwater for replenishment.

The impoundment facility is the most common type of hydropower facilities. A dam is built on a large river or lake to store its water in a reservoir. When water is released from the reservoir through tunnels it flows through a turbine. Since the height of the water behind the walls is so great, the released water goes through the turbine with a great force of energy. As the turbine spins, it sets in motion a generator, which in turn produces electricity. The water then travels back into the stream or river below. Networks of transmission lines and facilities carry the electricity from the generator to users in a form they can use. The Hoover Dam is an illustration of the process just described. When it was initially built, it produced enough electricity for the entire city of Las Vegas. As Las Vegas grew, they turned to other energy sources

The pumped storage hydro plant facility is able to store power. It does so by pumping water from a lower reservoir to an upper reservoir during low energy demand periods. When needs increase, the water is released from the upper reservoir back to the lower reservoir for electricity generation.

Hydroelectric plants require a lot of land in order to build a dam and reservoir. This requires a great deal of money, time and construction. There are not many ideal places to put them and most of these have already been taken. The good thing is once constructed; the electricity is free to produce. Due to costs, the tendency will be to put up smaller hydro plants that are more economical.

Hydroelectric plants using dams have a negative effect on the environment. Through the construction of a dam, there is a blockage of the flow from upstream to downstream. This disrupts the migration pattern of fish. Fish can also be killed passing through the turbines. An advantage to hydropower is the ability to control energy release to meet changing demands.

The population is growing and so will its power needs. Fossil fuels are being used up and there will come a time when they will be depleted. We need to turn to renewable energy sources to meet our needs. Natural resources seem to be a natural solution. Hydroelectric plants can meet our power needs without worries of depletion or pollution. It is also the most reliable source available today. Research and development is ongoing to provide a solution to the damage a dam can do. The potential for hydroelectricity is within our grasp and we must find a way to make this work.