There's been some talk about Russia blowing the dam at Kakhovka. They might do it, but, as usual in this operation, it would be a pretty stupid move. First, let's look at the terrain:
The dam is in the upper right corner. Kherson is on the right (north) bank, over on the left hand side, on a high point. In fact, the entire right bank up to Kherson is the bluff side of the river, meaning that destruction of the dam would mostly affect the left (south) bank of the Dneiper, the area where the Russians are withdrawing to. Unless they intend to skeedaddle all the way back south, down into Crimea, the resulting flood will hinder them more than the Ukrainians.
Long term, as I've mentioned above, the reservoir created by this dam feeds a canal which provides water crucial to Crimea. The Russians have had a hard time in Crimea since the 2014 occupation because Ukraine dammed the canal just short of the line of occupation, depriving the peninsula of water from this Soviet-built canal system. If they were intending to withdraw Crimea and hold it with hopes of returning to the Dneiper at some point, blowing the dam would not make sense long term.
I could see where someone commanding the army, desperate to cover a disorganized retreat, might find some short term expediency in it, or some Kremlin hack might think they could paint it as a false flag operation, but if anyone with a pulse gives this any thought, they will be reluctant to do it due to the consequences, and what it says about Russia's ability to ever prevail in this conflict.