To add some background. During WWII the allies successfully used massive specialized depth charges but those were much smaller dams. [0] During the Korean war the US struggled to merely destroy the sluice gates of a dam using aerial torpedos. [1] Eventually the Geneva Conventions were amended to forbid attacking dams if it would kill a large number of civilians (which was pretty obviously implied to begin with for what it's worth).

So unless Taiwan has a method to deliver something the size of a bunker buster to the underwater base of the upstream side of the dam I don't think it's going to happen. And if they did manage to pull it off they'd presumably be condemned as war criminals more or less universally.

[0] https://en.wikipedia.org/wiki/Operation_Chastise

[1] https://en.wikipedia.org/wiki/Hwacheon_Dam