There are a few things about blowing the dam.
- The HEPP there distributes its electricity primarily to the occupied regions of ZP and Kherson oblasts. So they do themselves no favours by removing the facility - they need it more than the ukranians right now.
- The flood plain in the event of failure would mainly be the south (or left) bank , again occupied.
- There is as well the issue of cooling water for the NPP at Energodar and what might happen there, and of course the winds are mainly westerly, again towards russian territory.
The russians can easily remove the roadway above the gates and eliminate it as a crossing point. No need for them to risk all the bad consequences above along with a huge international backlash.
I think the dam is safe unless the russians are really stupid. . Antonovski bridge though I am sure they drop in an instant when they withdraw, even that brings them huge problems - an end to any hope of ever taking Odesa ( I know but I am sure it is still in their heads). Plus it allows UAF to redeploy a lot of very good forces\resources from Kherson to ZP oblast.