Apparently from where the Ginninderra Creek joins the Murrumbidgee south to near Point Hut Crossing is prime Bunyip territory with sightings reported at both locations. A mythical creature (as far as we know) of Aboriginal culture bunyips are said to inhabit waterways, lakes and billabongs.
One story that had been told to me related that bunyips were a tool used by parents to teach children never to sleep near the river (floods I would imagine) however there are plenty of historical sightings of strange water beasts recorded in Australia. Here are a few local ones...
Queanbeyan Age and Queanbeyan Observer - Friday 4 October 1918