Still depends on where you are. I think it can still be tidal in fresh water because when the tide comes in, the volume of salt water can make the water level rise in the upper fresh areas. I am guesssing you are probably in a brackish area (salt and fresh, or lower salt levels). I have fished with cooked sausages in the Brisbane River, just outside of Ipswich, and landed a heep of huge catfish.