OK, thanks. One more. Two sets of rocks with a bluish color, opacity regulated by small PF, added a reflective shader (no RT), pops masked by a soft simple shape which is also used to color the terrain where the fall is a bluish color+ reflection, half coverage, only at steep areas (slope restriction). The rocks sit on an invisible plane which is fed by the same displacement as the terrain, be it with a few minor additions (river/fall area on main terrain a bit down, on plane a bit up to give the rock pops a rounded top).
Oh yes, and I wanted a hole behind the fall, so I used the painted shader to vdisp that area, and use it as mask to not give that area of the fall the water color.