A river bank is a boundary between land and water, between something that is solid and secure and something that is shifting and changing. If you dream that you are standing on a river bank, you have reached a boundary in your life. You could be preparing to begin a new phase in your life, or you could find yourself having to choose between opposing beliefs or between people who are in conflict with one another.
In a dream, water can represent the unconscious, the emotions, intuition and instinctive drives, so a dream about a river bank can symbolize your need to integrate your emotional, intuitive side with your practical rational side, which is represented by the land.
If you dream that you are standing at the bank of a river and then fall into the water, you are worried about not being able to control your emotions.