Flowing river shader

I’ve seen a lot of information about water shaders, but they seem to be either oceans or lakes. I’m looking to create a river - generally flowing in one direction. I’ve looked through content examples and plenty of tutorials, but I haven’t seen anything of the like. I’ve also seen people create flow maps, but I’m having trouble seeing how that would work, since every flow map I’ve seen is a perfect square, and so is their body of water. Since a river is decidedly not, what is the solution there?

I think one way of doing that would be creating a “road tool” with a spline component and adding a water material with a panner. There are helpful tutorials on road tools on YouTube and for the material you can just modify a traditional water material by adjusting the panner’s direction to your liking. I’m not sure if this is what you are looking for but i hope it helps!