The parts of a rivers system are River source or Headwaters- the beginning of the river or starting place. Tributaries- this is a river or stream that feeds into another river Channel- although this might sound like the famous perfume brand a channel is the course a river it carves across the landscape. Riverbank- this is the land next to a river, vegetation comes easily in these areas Mouth/Delta- This is the end of the river at this place the land flattens out and the water loses its speed. The systems of the river are portrayed in the picture below.