[HiTech RedNeck]

Now they did this, why? to get hydro energy?

How many nukes would China need to match the output of Three Gorges?

[Noumenon]

The TGD is primarily a flood control mechanism. Power is important, but perhaps not as important as that. Failure of that structure would be beyond catastrophic. Millions - and I mean millions - of peole dead.

The economic consequence would also be beyond catastrophic - the ensuing flood would destroy numerous cites with all of their industry and infrastructure. China would convulse with social upheval in the wake of this catastrophe. It's possible that China would do what it has always done when its dynasties and regimes collapse - revert to chaos and warlordism for a time.