The world’s largest dam is a mile anda half long and about 60 stories high. The $59 billion Yangtze River project was completed and put into service in 2003. Most extremely large construction projects have their detractors, but Three Gorges has been particularly criticized for displacing about 1.5 million persons and destroying hundreds of miles of viable farmland.  Its electrical generation capacity is more than eight times greater than Hoover Dam, but still supplies only two or three percent of China’s 2016 energy needs.