Wow. What ever happened to just putting fish into water? Just kidding. It's people like you who make hobbies interesting. You sound like when you get into something, you jump right in there! Good for you.
You will have to see how fast the water moves up there. If it always is running full blast, the fish will probably exhaust themselves to death. If you can make it so at least part of it is somewhat calm, you may be able to house some fish in there.
Man, I've never done anything like this, so I can't really advise you on this one. I'm willing to bet 98% of the users here haven't either.
I could suggest that you set it all up, get a feeder goldfish and see if it's possible for a fish to live in it, then try to get something fancy/colorful.
Wow........