Hydroelectric dams are essential to prevent flooding. Many of these dams are located in waterfront locations like the Mississippi and Ohio. Most dams are created to control river flow, improve navigation and regulate flooding. However, some dams are built to produce hydroelectric power, which is the case here (Smith). How do hydroelectric dams work? There is a power source that is used to spin a part called a "turbine" and then turns a metal shaft into an electrical generator, which creates electricity. (Perlman) Mechanical energy converts to electricity so that water flows through dams. It could also work without dams, which is a process known as diversion/run-of-river. This means that part of the water in a fast-flowing river can be diverted via a penstock to a turbine installed in the river. (Anderson) To get to the point, dams work by converting energy into electricity so that water can flow to our homes. There are many pros and cons about these hydroelectric dams! Some of the advantages are renewable energy sources, dams can store rainwater or water directly from the river, generate electricity, very few outages and finally, control flooding. These professionals really help us in a positive way. Then there is always something bad with a good thing. Disadvantages of dams cause rivers to become clogged, it disrupts the natural seasonal changes of rivers, ecosystems could be destroyed, and dams are expensive. There are three types of hydroelectric families: diversion, reservoir and pumped storage. hydroelectric plants use dams and some do not. (Walker). Sizes vary by size. For example, a small system for a house or a small town. These are also middle of paper names......turning hydroelectric water into electricity to power our cars, homes and appliances. In the future, the development of hydroelectric power stations will create local physical pollution. For example, industrial structures in a natural environment! Where are the hydroelectric power stations located? The largest hydroelectric plant is located at Grand Coulee Dam on the Columbia River in Washington. More than seventy percent of the electricity generated in Washington is produced by hydroelectric facilities (Thomas). Hydroelectric power provides about a fifth of the world's electricity. The five largest producers of hydropower in 2004 were China, Canada, Brazil, Russia and the United States. Hydroelectric dams have a positive effect on us and our environment. Without it, we would not have running water reaching our homes. And we would have nothing to prevent flooding! Dams are very useful to us.