Gates were closed to allow the water level behind the dam to build up to a very high level, which as you describe in comment#8 probably caused the power of the breach to get away from Russia’s more rational goals. Poor Pooty, again.
I doubt this scenario too. The whole powerhouse complex was demolished. You can see the whole structure is gone, and the water is running through the channel where the turbines were.
A demolition on the dam side could have caused the destruction of the dam, but not the powerhouse.
Type in my previous comment. Should read #108. Excellent detail on what probably went wrong, the Russians probably blew it up on purpose, and then it got much bigger that they had wanted or expected.
It will probably take 10+ years to rebuild it, in the meantime there will be less agricultural production from the area and possible famine in Africa…