Russia's Advantage in the Battle of the Negro Basin

A dam has been blown up and so a good chunk of the Negro River Basin has been flooded. Russia's fortifications on the other side of the river have been wiped out. A lot of the roads that Ukraine might have used in the course of a counter offensive have also been Wiped away. So we don't know who did this, but you you think it's the Russians. And if they do that, I mean that would be a remarkable thing to pull off.