Man-made dams are designed to stop or impede the flow of water along a river. While dams are most commonly associated with the production of hydroelectric energy, they are used for a variety of purposes. When a river is dammed, it creates an artificial body of water behind the dam. Such reservoirs are used to supply the public with drinking water and for regulating the flow of water to surrounding areas.
Hydropower provides 19 percent of the world's supply of electricity, reports the U.S. Geological Survey, with approximately 3,000 terawatt-hours generated annually. Hydroelectricity harnesses the kinetic energy of water to move turbines, which in turn generate electricity. Hydropower is clean and renewable and reduces dependence on fossil fuels.
Regulates Water Supply
When a river is dammed, the water pools and forms a reservoir. This allows population centers to collect fresh water during periods of heavy rainfall for use during droughts and dry spells. Dams can also be used to control flood water and supply a regulated amount of water to surrounding areas for irrigation. Consequently, dams provide a buffer to extreme or irregular weather.
Floods Surrounding Areas
When a river is dammed, water is displaced and surrounding dry areas are flooded. Often this results in the displacement local populations and the inability to use land previously accessible. This can disrupt local activities like agriculture. Moreover, when vegetation is engulfed in water, the dead vegetation releases methane into the atmosphere, increasing the production of greenhouse gases. Additionally, the loss of forestland slows the uptake of carbon dioxide, another greenhouse gas.
The flooding of surrounding areas displaces existing wildlife and can disrupt whole ecosystems. Furthermore, marine life that relies on the unobstructed flow of the river, such as salmon and other migratory fish, can be adversely affected.
- Photo Credit Jupiterimages/Photos.com/Getty Images
Advantages & Disadvantages of Concrete Building
The majority of concrete building is found in commercial applications, such as malls and individual retail stores. In some locations, residential homes...
The Advantages and Disadvantages of Flood Defenses
Flooding can result in significant damage to the economy, environment, infrastructure and property. Flooding can be caused by small watercourses, direct surface...
Dam-Building Techniques for Ponds
Whether you want to build your own swimming and fishing hole or water livestock, a pond can be a functional and beautiful...
Pros & Cons of Hydroelectric Dams
Hydroelectric dams, large structures usually made out of concrete that block the flow of a river or stream, are used to generate...
The Disadvantages of Hydroelectric Energy
Most hydroelectric energy is generated by damming rivers and then directing their flow through a large turbine. While this technology is very...