I've never made one like you have pictured (I think the above reply answers that anyway) another alternative is to use real rock.

I have made several for Mudskipper tanks.

If you have a pool set up on one end of the vivarium it is easiest but one can also be built in dish.

I would generally start by hitting the local fish store and selecting some nice rock that matches what you want. The benefit to using this rock is that you know it is safe. Alternately go collecting rocks but being paranoid like I am I would boil them 20 minutes, soak them in fresh water for a week changing the water daily and finally boiling one more time for 20 more minutes. This leeches any chemicals out of them as well as killing any nasties.

Either way once you have your rocks you get to spend a few hours arranging them so the water flows how you like and finally taking it all apart and using a marine grade silicone to put the whole works together.

I think the best way to feed the water is from an external sump where you can also have a filter and it makes hiding the pump much easier. But if you have a dish instead of a pool I'm not sure an external sump would work.

Either way I have more of an idea than an instruction, I apologize. I'll be building one shortly and I'll be sure to take pictures along the way and detail my methods if anyone is interested.