Why would Russians blow up the dam that is under their control, protected mainly their territory and supplies Crimea with water? Smell like yet another Nordstream nonsense. Not to mention previous threats and attacks made by the UA forces on Crimean-related infrastructure.

Also if you look at the videos the damage is to the upper part of the dam, pretty shallow.

EDIT: Also here is the Russia's official note to UN Security council from october warning of possibility of UA sabotaging the dam. And the WaPo article from december where UA side admits they do have plans and excercises for exactly that.

It's the same thing as Nord Stream.