Yeah, that seems to have been an own goal by the Russians, given that they would probably still have that fresh water today if the dam wasn’t destroyed. We may never truly know why they chose to do that, but it lines up with the indiscriminate destruction as acts of terror they have used throughout the war, just at a larger scale.

The importance of the canal has diminished since the start of the war, and eventually they would have lost control of the dam entirely, so that would have been a factor.