Not enough here, I fear, not enough: your work on the waterfall itself is, i think, rather good - not going overboard on the motion blur, and neither freezing the motion to make it look odd; but that is all you have here - very little context, and what there is is not very striking - rather dark, undefined, and therefore uninteresting to the eye - lightening, or simply increasing contrast in just those areas might go someway to solving that, but I think the process would only be part of what you need. There simply needs to be more for the eye to move through in the shot, some kind of shape to lead the eye to the waterfall, to maintain a sense of movement through the image. 4
Beautiful waterfall Nice detail I think another half inch off the top would improve this as the sky is very bright and really does not add to this image