Environmental Impacts of Hydroelectric Power Plants

Hydroelectric power plants sited on rivers and streams change the natural conditions of these water bodies through both short-term and long-term impacts. Therefore, changes in water quality, erosion, fluctuation in water temperature and water flow, and eutrophication must be studied in planning future hydroelectric installations. The objectives of this paper are to describe briefly the reported physical, chemical, and hydrodynamic changes associated with hydroelectric dams and to relate some of these changes to the fish and benthic communities of the lower Susquehanna River. Several aspects of the impacts of hydroelectric projects are briefly considered and changes in the lower Susquehanna River, the site of four large dams, are evaluated in light of disruption of the upstream runs of the previously existing migratory fishes. Changes in the structure of the benthic community are also analyzed based on literature reviewed.