Casper.
Thank you for this valuable link !
http://www.dtpli.vic.gov.au/__data/assets/pdf_file/0008/217853/RiverBoundaryDetermination.pdf
I have spent many unsuccessful hours trying to find anything like this in the current legislation and relevant authorities publications, a statement such as the one below. This quote is from the link you posted.
"There is reference in the 1881 gazettal of quite a number of rivers having reservations
existing not only on the main stream but also over their tributaries. It should be understood
that no reservations exist on tributaries of tributaries. For example the Watts Rivers is a
tributary of the Yarra River and is subject to a 20.12 metre wide reservation along each
bank but Chum Creek, Grace Burn and Donnelly Creek, being tributaries of the Watts
River are not subject to the 1881 Order in Council."
Now to find the original 1881 gazette.
A river/creek tributary of an exempted list river or tributary MIGHT be allowed to be prospected in/on if not on the list itself and be an area such as crown land or state forest that is not excluded for the purpose of prospecting.
This link also shows how much a river can change course of a relative short time and leave deposits where SOME may not expect or look.
My quest continues