Here is how it works everyone: the zig zag is flat and slightly bent. The water is not flowing, but hovering. the towers are not actually aligned like that, but rather individual sticks that make the illusion of a non-euclidean surface. the waterfall is the trickery here: it's not flowing from the end of the zig zag, but some other source that is hidden in the contraption.
The water is not recycling on itself. Since the zigzag is mostly flat (very slightly tilted downward I would imagine, with a barrier at the end tilted the other way), the water merely stays where it is. The waterfall water probably comes from a tube fed through the tower (or something like that). You can see the water source *turn on* at a certain point, and the water wheel responds to that and the flow in the zig zag looks consistent because it is being fed by the tube.