Tumut 3 Power Station Opens as Australia's First Pumped-Storage Plant
CONFIRMED82% CONFIDENCEA contemporary Canberra Times report (as quoted by Tumut local history archives) states Tumut 3 Power Station opened on 23 October 1972; Wikipedia[2] corroborates the station entering service in the early 1970s.
Tumut 3 became Australia's first major pumped-storage hydroelectric plant, eventually reaching 1,800 MW of generating capacity as part of the Snowy Mountains Scheme. Three of its six units, fed by Talbingo Dam, can also pump water back uphill overnight at a combined 600 MW using cheap off-peak power.