Crimea's integration into Russian Federation:

They need to deliver nuclear power for these plants.   Crimea only recently got enough local power generation capacity.   Throwing in
energy hogs like desalination plants will put the system under stress.   One way or another, new power will need to be deployed for
these plants.

This is a good excuse to build a nuclear power plant near the Kerch Strait bridge to provide electricity all the way out to Sochi.
The area to the east of the strait is flatland and only becomes mountainous east of Anapa.