List three pros and three cons of China's Three Gorges Dam

Answer 1

On the plus side, this largest dam ever built—1.3 miles (2.1 km) wide and 610 feet (186 m) high—has created a reservoir 385 miles (620 km) long that will dramatically reduce the threat of downstream flooding. Stored waters will also help alleviate drought. The Three Gorges Dam will also improve navigation and therefore enhance trade, especially by connecting the burgeoning inland city of Chongqing to the world abroad.
Most of the negatives are related to the vast reservoir forming behind the dam. The new 500 feet (150 m) deep lake has inundated 4000 villages, 140 towns, 13 cities, numerous archeological sites, and nearly 160 square miles (over 400 sq km) of farmland. Because their homes were to be drowned, as many as 1.4 million people were resettled. Many of the vacated settlements were quite ancient, and their inhabitants had deep cultural roots in them. The old villages were typically situated close to fertile farmlands that were also inundated. In the new, higher communities into which people were located, soil conditions are generally inferior.
The reservoir has had aesthetic consequences too, erasing a world-class wondrous wild river running through scenic canyons. There are also practical concerns about the silt that is building up behind the dam. It is possible that this increased soil load will have the ironic effect of causing flooding upstream from the dam, even as the dam prevents flooding below. There are fears of the almost unthinkable: that the dam could burst, causing unimaginable devastation and suffering downstream. Finally, there may also be seismic consequences of the dam.