9.3 Social effects of hydroelectricity
The rising water behind China’s Three Gorges dam (Figure 18) submerged about 100 towns and displaced over a million people. It is estimated that during the second half of the twentieth century, some 10 million people were displaced by reservoirs in China alone.
But even for the people immediately affected, the building of dams can have very different consequences. For those living in a valley that will become a reservoir it means the loss of their family home, possibly their livelihood, and often their entire community. In contrast, for people living on a river that periodically overflows its banks, the barrage and embankments of a hydroelectric scheme can bring freedom at last from devastating floods.

In the next section you look at what can be deduced from both the physical and social effects.