The article said 200m was a good usable head height and the Kalgoorlie super pit is nearly 600m deep and 3.5km x 1.5km. All they need to do is dig out and line the top tank/s and run the pipes down to the turbines, generators and pumps.
Maybe have that equipment lowered down on steep tracks with cables so they can raised and lowered to suit water levels and for maintenance?
