OK - found the geocache thing - thanks to those who pointed me in the right direction.
For those interested, here is the page describing the terrain and how difficult it is to get to that geocache:
http://geocaching.com.au/cache/gc2d7dc
And here is the description of the geocache by the folks who placed it there:
http://www.geocaching.com/seek/cache_details.aspx?wp=gc2d7dc
I should mention that the little creek that joins Kholo Creek just upstream from the bridge, near the bend in Kholo Creek is called Ugly Creek.
So that may explain why the kayaker was going up into Kholo Creek. But from the descriptions of people trying to get to the cache, the terrain doesn't seem likely to be easily got to, especially with a body.
Unless she was thrown over the bridge. I am really interested to find what injuries she would have had from the autopsy - apart from a chipped tooth....