Pete,
The Dam will be chockers with anglers from about Sept onwards regardless of competitions.!!
Are you talking about the MASA family fishing classic in Oct 11 12th??....If so, you should be OK. I caught good fish in the comp and in the week after last year. The fiasco of the fishing comp causes fish to hide a bit...when your there straight after should be a bit quieter...find water by yourself. dont get sucked into the mentality that the fish are where everyone else is...they tend to follow the leader during this time of year. In truth the fishing will probably be quite the opposite! Find a nice quiet area of the dam, have a nice quiet session in a nice quiet area, and you should be fine. There should be some up-to-date info slashed around here leading up to the time regarding tatics etc. We will try and help as much as possible.
If your talking about the fiasco that is the Ausfish Vs Monduran in Sept...well that may be a different story....
cheers steve