Jeremy - First you must remember that a dream is like a seed, it is something that comes from a deep part of you; it is something that is working upwards toward being conscious. As such it often, like a seed, takes time to break through to the surface, and then it has to grow. So often dreams are not recognised for their full meaning until later – sometimes months or even longer. The dream images are attempts to communicate something that has probably never been thought about or even been consciously thought about, so has never been put into common conscious thinking before. It is a communication from the depths, from beyond thought, and so any interpretations that are given by thinking may completely miss the point.
Your dream shows you breaking out or leaving behind a state of mind or attitudes and beliefs that were literally like a prison. You must have then in the dream state relaxed and experienced your natural self outside of what you have been or known in the prison state.
In exploring this new condition you saw or realised what an enormous energy pours through you - the waterfall - and you also realise that this was something passed on to you from past generations. The great waterwheel is probably your central energy production, but in some way you have a strange view of it as if you have to be part of it. I am not sure of this, the meaning of the family in the wheel - it may be an attitude that you had to work hard to survive and this has passed on to you.
Then you are there with your fiancé and you are in a relaxed relationship with her - a good ending to feel at peace with your inner female.
Tony