Phrase occurs in Bill Staines song, "River" Lyrics can be found with music and guitar chords in the Folk Legacy soft cover book, "If I Were a Word, Then I'd Be a Song; Songs by Bill Staines", page 84. It's six verses long. The chorus contains the phrase RIVER RUN DOWN, and it reads: "River, take me along, in your sunshine sisng me your song, Ever moving and winding and free, you rolling old river, you changing old river, Let's you and me, RIVER, RUN DOWN to the sea"I hope this is what you are looking for.