Using water jets to create waterfalls just feels fake, and it's not exactly realistic looking either. My suggestion is to make water naturally fall if there is a cliff or edge for it to fall from, as long as there isn't a path or a ride at the bottom.
How this works is you would create some sort of reservoir with one side missing and a reservoir below. You place the water at the top and it naturally falls over the edge.
How this works is you would create some sort of reservoir with one side missing and a reservoir below. You place the water at the top and it naturally falls over the edge.