Abstract
This paper describes the potential hydropower (HP) and water resources and developments to replace fossil and other conventional world's energy sources in the near future. Hydroelectric power has an important role to play in the future and provides considerable benefits to an integrated electric system. HP provides more than 97% of all electricity generated by renewable sources. The social, economic, and environmental impacts of large hydropower, however, highlight the serious limitations of large hydropower in sustainable energy development. HP is a clean energy source. It prevents the burning of 22 billion gallons of oil or 120 million tons of coal each year. HP does not produce greenhouse gasses or other air pollution. HP leaves behind no waste.