I carved the waterfall texture right off of the wall and used that as the sides of the structure. I then created a cutfile that creates the pieces I need to build the inner structure. I designed it as a solid center to which I glue the sides. This made it relatively easy to assemble, and very sturdy.
I'm also thinking that I can easily modify all of this to make a second waterfall piece that carries from where this one leaves off, allowing for even more terrain variations.
I'm hoping it won't be too had, but I would like to rebuild the wall so that it doesn't have the waterfall texture on it. This would make extending the waterfall out from the wall look better.
This is probably all I'll get done today.