Here is gif about how waterflow works: http://i.imgur.com/2Rm0bCA.gif
This is my implementation of "water flow shader" for UPBGE. Thanks to new time node we can create this effect pretty easily. I dont know if there is already solutions for this effect for BGE, I just wanted to create it myself.
Here is blend file with node structure if someone interested. This is not only for water, this is for any liquid structures (lava, for example, or you can create pretty simple and effective wet glass if it is rain in your game)
You need upbge 1.7 or higher