Cycling in Sydney Australia
No specific knowledge but I have seen other mentions of fairly capricious, irregular and unpredictable opening & closings. A whinge to Sydney Water does not seem to help, Robflyte is through there more often maybe he knows more, it is annoying.
I know nothing
Gate being randomly shut is discussed regularly on BNA forum under Greystanes Canal or Prospect Dam or Western Sydney paths etc. Seems there is caretaker who shuts the gate when it suits him, not when the Sydney Water website says it will.