Creation Common purposes Function Example Power generation Hydroelectric power is a major source of electricity in the world. Many countries have rivers with adequate water flow, that can be dammed for power generation purposes. For example, the Itaipu Dam on the Paraná River in South America generates 14 GW and supplied 93% of the energy consumed by Paraguay and 20% of that consumed by Brazil as of 2005. Water supply Many urban areas of the world are supplied with water taken from rivers pent up behind low dams or weirs. Examples include London, with water from the River Thames, and Chester, with water taken from the River Dee. Other major sources include deep upland reservoirs contained by high dams across deep valleys, such as the Claerwen series of dams and reservoirs. Stabilize water flow / irrigation Dams are often used to control and stabilize water flow, often for agricultural purposes and irrigation. Others such as the Berg Strait Dam can help to stabilize or restore the water levels of inland lakes and seas, in this case, the Aral Sea. Flood prevention The Keenleyside Dam on the Columbia River, Canada can store of floodwater, and the Delta Works protects the Netherlands from coastal flooding.http://www.nae.usace.army.mil/Missions/Recreation/BlackwaterDam.aspx Land reclamation Dams (often called dykes or levees in this context) are used to prevent ingress of water to an area that would otherwise be submerged, allowing its reclamation for human use. Water diversion A typically small dam used to divert water for irrigation, power generation, or other uses, with usually no other function. Occasionally, they are used to divert water to another drainage or reservoir to increase flow there and improve water use in that particular area. See: diversion dam. Navigation Dams create deep reservoirs and can also vary the flow of water downstream. This can in return affect upstream and downstream navigation by altering the river's depth. Deeper water increases or creates freedom of movement for water vessels. Large dams can serve this purpose, but most often weirs and locks are used.
Creation Common purposes Function Example Power generation Hydroelectric power is a major source of electricity in the world Many countries have rivers with adequate water flow that can be dammed for power generation purposes For example the Itaipu Dam on the Paraná River in South America generates 14 GW and supplied 93% of the energy consumed by Paraguay and 20% of that consumed by Brazil as of 2005 Water supply Many urban areas of the world are supplied with water taken from rivers pent up behind low dams or weirs Examples include London with water from the River Thames and Chester with water taken from the River Dee Other major sources include deep upland reservoirs contained by high dams across deep valleys such as the Claerwen series of dams and reservoirs Stabilize water flow / irrigation Dams are often used to control and stabilize water flow often for agricultural purposes and irrigation Others such as the Berg Strait Dam can help to stabilize or restore the water levels of inland lakes and seas in this case the Aral Sea Flood prevention The Keenleyside Dam on the Columbia River Canada can store of floodwater and the Delta Works protects the Netherlands from coastal floodinghttp//wwwnaeusacearmymil/Missions/Recreation/BlackwaterDamaspx Land reclamation Dams (often called dykes or levees in this context) are used to prevent ingress of water to an area that would otherwise be submerged allowing its reclamation for human use Water diversion A typically small dam used to divert water for irrigation power generation or other uses with usually no other function Occasionally they are used to divert water to another drainage or reservoir to increase flow there and improve water use in that particular area See diversion dam Navigation Dams create deep reservoirs and can also vary the flow of water downstream This can in return affect upstream and downstream navigation by altering the river's depth Deeper water increases or creates freedom of movement for water vessels Large dams can serve this purpose but most often weirs and locks are used