Simulating moving water?

I have tried some of those out in the past. Interesting results though I had to use a lot to cover any significant area. I have a river that is almost one km wide.
Good morning !
Why not just trainz water? You spread water in two different places. If the surfaces are not touching, you can put them at different altitudes, and they will stay there.
If you create several, separated by the minimum distance, therefore not contiguous, and you position them at fairly close altitudes, you can join them by creating one of the minimum width between the two and obtain a slope. Here, it is exaggerated for the purposes of demonstration !
Try and enjoy.
It works in TRS19 and Trainz+. Not tested with TRS22