To dream that you fall and are not frightened signifies that you will overcome your adversities with ease.
To dream that you fall and are frightened indicates a lack of control, insecurity, and/or lack of support in your waking life. You may be experiencing some major struggle and/or overwhelming problem. It may also imply that you have failed to achieve a goal that you have set forth for yourself. Dreaming that you fall backwards suggests that you prevented yourself from making a bad decision or mistake. It may also mean that you are not ready to move forward and need to take a step back.
To dream that you are free-falling through water indicates that you are feeling overwhelmed with emotions. You may feel that it is easier to give up, then to try to stay afloat or prevent yourself from going under.
*For an in depth analysis, please see Common Dreams: Falling.