I have managed to get a nice random/procedural terrain generator plus lakes working based off of Perlin noise and seeds, but I wish to create rivers in flat bits of land. I have had a look around and can’t find anything relevant?
When you generate the terrain with perlin noise, you get set some kind of number which presents the “sealevel” height on the Y-axis. Once you’re done generating, you can add set the with of the standard water prefab to the size of the map. (renderer.bounds.size). The mountains or peaks which have a higher Y-axis value than the sealevel, are land, the one below are sea. Heres a picture of the side view
This is something I’m researching and I’ve found a paper that investigates procedural river generation from river networks, to meandering techniques and the creation of river deltas…
Sections 5,6 and 7 may be of particular interest to you…