Dams are built across flowing bodies of water and tend to serve two purposes. Some dams have virtually no water reserve storage capacity. The picture shows the various components of a hydroelectricity generating dam.
Dams are the most largest man-made structures on the planet.
The Itaipu Dam in South America stretches for nearly 8 km across the long Parana river. 11 million cubic metres of concrete were used to build the dam - enough to build four or five new cities . At full power, its generator outputs over 12 MW of electricity. This page was produced by Arif Rahman for the Database for Use in Schools project. All views expressed in this page and all others for this project are the views of the author and not necessarily that of Southampton University.