Because I don't know, I will listen to anything BUT:
So far I/we are told that the Ruskies were in control of the dam. If they were in control of the dam wouldn't they be the ones controlling the dam and the water height......?
Also, even if the Ukrainians were in control- which we are told they were not- if it is muddy and shallow along the sides of the river and they were planning a major amphibious assault it would be to their advantage to increase the water depth for their crossing.
Don't know. Just sayin.