I was thinking the same thing, only problem is i HATE the look of a waterfall coming out of nowhere (way above grade). I really like that idea, maybe figure out a way to keep the grade higher on the back a bit, keep the rock retaining wall going around the pond a bit? The grade goes away from the house obviously.
I also REALLY wanted to implement a stream going through a walk, with a couple stepping stones in the creak to get across. My friend did a pondless with this and it was AWESOME