The ability to draw (I assume you mean with traditional hand tools) would be beneficial but I'd argue that it isn't necessary or at least isn't highest on the list of attribtutes needed to create logos in the digital world.

I think that creativity, an artistic, imaginative mind, is more important than technical ability. Taking two people, one who is brimming with creativity but is only proficient with drawing tools, and one who somewhat lacks inspiration but is a master artist when it arrives... the former will be my choice every time.

As an aside, I've been designing logos on and off for many years. I have, honestly, not got a particularly creative mind and cannot draw (pencil on paper) to save my life. However, I can sketch out the dozens of ideas for any particular logo venture on paper (very crudely!) and embellish those in my head before transferring those ideas into something real (as real as digital images get). So, yes, I'd say that you definitely can get away with rough sketching skills. If I can do it, anyone can!