Which one of those 2 meanings?

The river went heavily by towards the sea between the banana plantations.
What is the exact meaning? The first one or the second?
1. With heavy or laborious movement; without animation. OE.
2. Forcibly, violently; strongly; severely; to a heavy degree. OE.
Thanks

I think the first; I would envision a "heavy" river as one that is slow and thick with mud and silt, probably with water that looked like chocolate milk.