New Viv

Having had ribbon snakes , your set up is very nice however I would only provide a water bowl for drinking .

They will get blisters in captivity with to much water.
Keep in mind most of their area is dry and they only frequent water for food and to drink.

You could put a flat piece of corkbark in that area which they will certainly hide under or leave it an open area but that much water is not needed and more problems than not.