"HARD ROCK, SOFT WATER" does meet the qualification of the 2 second challenge. I think you had a great idea in trying to capture a close up of the water and its movement.
Looking at the image, it seems over exposed. The colors are a little too bright, especially on the leaves the almost look unreal. The timing of the water was nice. I think the shot is framed very well. You left the leaves in the shot, which allows you to stand out from the rest of the water/waterfall entries. Also the focus seems a little off, possibly the camera was not on a sturdy tripos while you had the 2 seconds going.
Unfortunately I really think the exposer hurt this piece. But I was looking at your portfolio and based on your work, I really have to wonder if you wanted the shot to look like this. Even more so since you named the piece HARD ROCK maybe you were trying to go with an edgy/harsh piece.
Overexposed, this shot definately needed a smaller aperture, a lower ISO setting or a ND filter (or just to be taken at a different time of day). Nice try though but watch your histogram next time.