The water flows into a drain on the back side.

Was this a drain system you had custom fabricated or did you find a ready made and then fabricated your sink to the drain specs? I'm working on one of these for a client and we are running into some dead ends when it comes to drainage. I appreciate any advice you can share.

We discussed the option of having the granite maker custom build the granite sink and he suggested that there be a sink under the cabinet that the water drains into that goes down the drain system. You just want to make sure that you are able to clean that sink under the cabinet