Possible Clues:

• Cascade
• Cataract
• It cascades down a mountain
• Downpour after crashing through barrier
• The ebbing tide?
• Current source of power, possibly a force in the north
• One of the aqueous drops used for a cataract
• What a comedown that was for Jack and Jill!
• Drop of Adam's ale, a force in the north
• A raft well adapted for hazard on the river