Hydropower dates back to the use of waterwheels to grind grain in Greece over two thousand years ago. Modern hydropower is a mature industry that has been used to generate electricity since the 1880s by capturing flowing water with a dam or other diversion structure and channeling it through a waterwheel or turbine. According to a 2012 report by the International Energy Agency, internationally dams are responsible for the largest amount of power generation from a renewable source; yet they have come under scrutiny as a result of environmental and social impacts perceived to be unsustainable (McCully 2001). Specific impacts, and their severity, vary from project to project and are related to social, political, economic, historical, regulatory, and environmental conditions, which also influence benefits such as job creation or watershed management
