And I could easily flip the question around to OP. Why would Ukraine blow up their own dam, flooding their own territory and potentially crippling their own nuclear power plant? And making a counteroffensive across the Dnipro river that much harder?
It's not to deprive Crimea of water ahead of the counteroffensive, Crimea's reservoirs are full right now so they've got a year's worth in the tank. That's about the only possible benefit I can think of that Ukraine might have got out of this, and even if it were so it would be a trivial benefit compared to the costs. Crimea's water supply isn't going to make a difference to the actual fight that's about to happen there.
To divert resources from/mess up Ukraine's planned offensive.
Also they haven't exactly been below causing great suffering for civilians simply because they can throughout this war.
My speculation as to why they would do such a horrible thing is because they know they can't hold the position and want to cause as much damage as possible before they leave. Why would they bomb civilian targets like apartment buildings?
But if Russia did destroy the dam, he says, it might have hoped to protect its western flank by complicating Ukraine’s offensive moves. “We know the Russians have form for this sort of thing,” he argues, pointing to Stalin’s destruction of the Dnieper dam at Zaporizhia in 1941.
Putin is not a communist and no serious communist claims otherwise, being against NATO and the US's proxy war against Russia does not mean that I support Putin and his horrible government.
Poland, NATO say missile strike wasn’t a Russian attack
PRZEWODOW, Poland (AP) — NATO member Poland and the head of the military alliance both said Wednesday that a missile strike in Polish farmland that killed two people appeared to be unintentional and was probably launched by air defenses in neighboring Ukraine.
“Ukraine’s defense was launching their missiles in various directions, and it is highly probable that one of these missiles unfortunately fell on Polish territory,” said Polish President Andrzej Duda. “There is nothing, absolutely nothing, to suggest that it was an intentional attack on Poland.”
Edit: downvoted for correcting misinfo quoting NATO and the Polish government, that's pretty funny :P
If you are a podcast listener type. The War on the Rocks podcast has been pretty extensively covering the war in Ukraine and has some really good insights. I wouldnt be shocked if they cover this incident in a future episode.
Not the OP but to create chaos and divert resources to aid the area would be my guess. Creating a sense of fear and uncertainty is one kind of tactic in my opinion.
Crimea depends on water via canal from Ukraine-controlled territory, which Ukraine shut off as was their right. This must be the big f u back in retaliation.