If it the river is static, your unconscious may have been commenting on your lack of drive and direction.
If you threw a stone in the river, did the ripples that formed echo your sense of going around in circles in waking life? The river depicts the richness or poverty of your life energy, so if you are crossing a river in your dream, this suggests you are in the process of making great changes in your life.
If you are in the water to cross, it means you will feel a lot of emotions in the process of change.
If you see someone else cross the river or fall into the river, this may refer to your feelings about aging and the passage of time.
If the river is contaminated, this suggests that you are holding back your feelings in waking life and not doing the best you can for yourself.
If you were in a river—or steamboat in your dream, this may refer to the circumstances that surround you, for example your family or home life. The context of the dream and how you feel will all help you with the interpretation. Was the boat solid and safe like a steamer, or fragile like a canoe or a dingy?
Canals, dams and reservoirs are all designed to regulate water flow and in dreams they suggest conscious attempts to control emotion; how effective they are at directing the water mirrors how effective you have become at controlling your emotions in waking life. A canal may also symbolize the birth canal and thus represent a desire for children. Because reservoirs are where water is collected and stored, if one features in your dream, could it be commenting on your own emotional reserves? The water level of the reservoir in this dream is important.
If it is high, your emotional resources are abundant but if it is low, you may be feeling emotionally drained by the demands of others. In dreams, dams also suggest control over your emotions, and their effectiveness in your dream will say a lot about your emotional health. If, in your dream, you were standing on a bridge watching the water flow beneath you, you could be ready to leave the past behind—as suggested by water under the bridge—since you are at a turning point in your life (the bridge is a symbol of transition).