This old one runs forever,but never moves at all.He has not lungs nor throat,but still a mighty roaring call.What is it?

Question

I run forever,
With a roaring call.
Yet I have no throat,
Or any legs at all.

Rock wears away,
Whilst I grow.
You try to race me,
And receive a blow.

What am I?

Answer 1

RESULT: A Waterfall