Hydroelectric Power Plants and the Environment

Ennerdale Water is a clean glacial lake in the Lake District National Park in Cumbria, England. No roads lead to this lake.

The construction of a hydroelectric power plant always has some impact on the environment. Large dams and reservoirs can flood vast areas, significantly altering or destroying existing ecosystems. Their construction may also require the relocation of large numbers of people and can endanger places and structures of great cultural value.

During the construction of the Aswan High Dam (map), many ancient temples had to be moved stone by stone. The filling of very large reservoirs can also induce seismic activity by changing stresses and water pressure in the underlying rock.

Once filled, a reservoir can provide additional benefits such as flood control, water supply, recreation and tourism. However, the operation of a hydroelectric power plant continues to affect the environment. Dams can obstruct fish migration and alter natural river flows, sediment transport, water temperature and aquatic habitats. Some reservoirs can also release greenhouse gases, particularly methane, as submerged organic matter decomposes.

One of the most serious risks associated with large hydroelectric power plants is dam failure or overtopping, whether due to extreme floods, structural failure or human error. Such accidents are extremely rare, but they can cause major material damage and loss of life.

7 pictures

7 pictures