ive seen this in other parks and i'd really like to use it in mine, there are waterfalls that appear out of thin air!?! How do you do this....?

when you build the waterfall, drop the land and as you know there's a pop up that says you'll mess everything up if you do this, but ignore it. Just move it off to the side and lower the land. I'm pretty fure that's how it's done. I did it once a long time ago. try it out.

theres a downside to this though if you make a lake or fill somthing with water then empty it, it could get messy the terrain where the old waterfall was will be all messed up.... I dont know if they fixed it, even though the trick is technically a bug