Question

why does water appear white when it falls from a height

Answer 1

Water falling from a height appears white is due to a phenomenon called non-selective scattering. When water falls from a height with high velocity, lot of tiny water droplets are formed around the falling mass of water due to the bombardment of water with the rocks.

Answer 2

Water qhen falls from height with a great velocity then te scattering of water droplets occur due to the opposition of natural sources like mountain or rock.
so the bombardment of water results in to the white colour