This is how he Hydroelectricity works: the water flows to the turbines and out into the river. The turbines turn and produce electricity. Then the electricity goes out through the power lines.
Animation of a hydroelectric power plant in a dam  http://ga.water.usgs.gov/edu/hyhowworks.html
Animation of a hydroelectric power plant in a dam http://ga.water.usgs.gov/edu/hyhowworks.html

Animation of a hydroelectric power plant in a dam http://ga.water.usgs.gov/edu/hyhowworks.html



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This is a picture of a genarator getting power from hydro energy



Cartoon version of how Hydroelectricity works