How much does a hydro-electric dam cost?

Dams are very expensive, so they aren't a very good idea in low economically developed countries (even though they are great help to prevent flooding). Remember also that prices vary depending on when they are built, how large they are, and many other factors.

Some examples of building prices:

• Itaipu Dam: $20 billion
• Hoover Dam: $49 million
• Fontana Dam: $70 million
• Tarbela Dam: $25 million
• Three Gorges Dam: $$22.5 billion