Alluvial Fan

Turtle River Watershed Conservation District
An alluvial fan is a fan-shaped deposit that is formed where a fast flowing stream eventually flatten, slows down, and then spreads out at the exit onto a flatter plain.  Slowing of the flow as the stream gradient decreases, course-grained solid material carried by the water is dropped.  This in turn will reduce the capacity of the channel and gradually build up a shallow conical fan.
The main benefit of the alluvial fan is the quality of water downstream after the filtration process is complete.  From protecting this area we can assure that the downstream quality of stream will continue to be stable and provide habitat for fish and wildlife species.