In this video Paul Andersen explains how energy can be harnessed was water moves through a turbine. Three types of systems are discussed in the video; run-of-the-water, impoundment, and tidal. Several advantages and disadvantages of dams...

Dr. Forrester describes the ways that severe environmental conditions, such as earthquakes, wildfires, mudslides, and droughts, challenged settlers in the United States. She talks about how the Hoover Dam was built for flood control. She...

Experts increasingly question whether the Three Gorges Dam can do the job it was designed for.