I would like to suggest adding sprites for more directions of waterfall flow. This would make them so much more useful when designing scenarios, because we could place them anywhere and have them work with the ‘flow’ of the water source we are designing. At the moment, you can basically only set them to flow southeast, southwest, and south, so if there were sprites for the other 5 directions, we could make some really cool river maps.
I think that there are actually a lot of similar SE units that could use such an upgrade. As for instance, it never made sense to me that we did not have bridges for West/East, North/South. I know that one might entail more because of the actual function, but it would be cool to have. Also, I remember a building from HD that was basically a wonder, but had no victory effect could be ‘rotated’ to allow you to use any civ’s architecture. I think it was called a Palace. Very useful in custom scenarios.