http://www.epa.gov/cleanenergy/energy-and-you/affect/hydro.htm

Although hydropower has no air quality impacts, construction and operation of hydropower dams can significantly affect natural river systems as well as fish and wildlife populations.

What potential harm to the environment does hydroelectric energy have?

http://www.waterpolitics.com/2014/04/02

http://www.waterpolitics.com/2014/04/02

Question 5