The Three Gorges Dam is the largest hydroelectric power station in world, in terms of installed capacity. And it affects the rotation of Earth and changes the positions of North and South poles!
Now, how it affects the rotation?
It's reservoir has a stunning capacity of 39 trillion kilograms of water, which it lifts through a height of 175 meters. This affects the moment of inertia of our planet and slows down the rotation of Earth.
This has led to increase of 0.06 microseconds (not noticeable, of course) in a day's duration! The Earth, has become flatter (only slightly) at the poles and rounder in the middle. Also, the poles have shifted by 2 cm.
This dam has affected millions of lives. A lot of activists had tried to bring this to the notice of the world, but couldn't. Ranging from possibly one of the biggest deforestation activities in the world, to mass displacement and rehabilitation of Project Affected Persons (PAP), this structure has had its share of controversies, though, they have been managed quite well.
This post was originally published on Quora