You should have access to the yahoo hi-res sat imagery in Melbourne, you just need to load the area in your favourite editor and then get the yahoo imagery to load.
From there you just draw an approx line along the water way and tag waterway=stream.
If you want more details/help message me directly, or join the talk-au list and we'll be happy to help.
OpenStreetMap
Discussion
Comment from JohnSmith on 2 October 2009 at 15:22
You should have access to the yahoo hi-res sat imagery in Melbourne, you just need to load the area in your favourite editor and then get the yahoo imagery to load.
From there you just draw an approx line along the water way and tag waterway=stream.
If you want more details/help message me directly, or join the talk-au list and we'll be happy to help.