accessing creeks

Some good looking creeks running under roads in my part of the world.
They've been named.
They run through private property.
I would knock on the door and ask if I can have a poke around, but am I able to anyway?
Are all named creeks in Vic crown land or not?
I can't seem to find any clear answer. Waiting on answer from local DELWP bloke.

1st thing to do mate is check if it's on the exempt(banned) list
http://earthresources.vic.gov.au/ea...ess-rules/list-of-exempted-rivers-and-streams

Then see if it's public land

http://mapshare.maps.vic.gov.au/MapShareVic/index.html?viewer=MapShareVic.PublicSite&locale=en-AU
(that site often doesn't work)

IF the area is in a parks vic area check to see if it's in the allowed parks fossicking areas, that list overrides the banned creeks list.
IE reedy creek in eldorado is on the banned list, BUT it's in a park where they stipulate an area that is open to fossicking.
http://parkweb.vic.gov.au/visit/popular-activities/fossicking

As a general rule, say a bridge going over Creek, the rta/rms/ council would own a certain distance from the road to the front boundary. Land holders are known to fence up to the bridge, blocking access with the need to jump a fence that really shouldn't be there.
Best advice really is to do a door knock.
They may even show you a better spot on there property. At the least you wont get yourself in a hostile situation, even if you are technically in the right.

Not sure about Victorian regulations, but generally u can't dig at all within a set distance of any bridge. Some states have mandatory access to waterways, but the rules vary from state to state and if it is anything like around here then u need to find out exactly what is classed as a waterway as a stream running into and out of some properties can be listed as a waterway yet the stream within the property is not. So yeah your best bet is always to talk to the landholders and get permission.