Hi,
I'd agree with the above comment, an ND filter, or a couple of them together will increase your exposure time, at the moment the water in the foreground looks like it is suffering from motion blur rather than showing the silky effect you can achieve with long exposure. Rather than 1/3s exposure, I'd be pushing this to 10s+.
The underhang on the rocks is a little dark for me, particularly where they are such a large portion of the image. Again the ND filters would help with this, increasing the detail in the rockface.
The framing is good, but I'd consider pointing the camera higher if possible, the left foreground is a bit bare and the waterfall is a bit more centred than I would like, pointing the camera up slightly would place the waterfall in the lower centre of the image and remove the blandness of the expanse of water in the front.
Hope this helps,
Steve