The fear of drowning could be part of what is causing the dreams. In the dreams, you are taking positive action and that's good. It may mean you are taking action in real life to either avert or solve everyday problems.

The dreams could also be about escaping something. Water often represents one's emotional state. Perhaps you are subconsciously trying to avert a painful situation, most likely from your past. The wall of water represents your subconscious, the place where emotions and memories are buried or "walled off." When you become conscious in the dream could be the time when you are heading up to your conscious mind, via the mountains and attic.