Im at the end of the cave and there is a waterfall that i need to get up how do i do it?

I had to use whirlwind spirit to get up there. Couldn't find any other way in.

If you're at Stony Creek Cave there is a dwemer ruin on top of the mountain called Kagrenzel you go through there to get the find what you are looking for. Also watch out for the drop

Use the http://www.gamesas.com/forum/196-dawnguard-cheats-hints-and-spoilers/ for this kind of topic.