hi Lisa, very difficult finding information re your request. The best place to start maybe the Melbourne Water (used to be MMBW) head office in Melbourne. Not too sure if they have archives – but I think they would.
Aside – I lived and went to school at Cocoroc and was in the last intake of students there in 1970. My mother ran the Cocoroc post office until it closed. 3 generations of my family worked at the farm. Have many memories – but unfortunately no photos. In fact – the photos of the time seem rare. I lived on the Werribee farm for the first 7 years of my life. Remember the names – Ryan’s, Saddlers’, Smith’s.
I will be interested to know if you find anything. Please let me know.