Very nice photo! I find it very hard to make an acceptable picture of a waterfall. There are so many things to consider. Often the light is rather dim, the contrasts are harsh, and you have to decide what effect you want to create. While I already experimented with ND filters in order to create the impression of silky, flowing water, I was not very content with the results. So, for most of my waterfall pics I also use a very short exposure time. Well done!