These images show the Coalcliff and Stanwell Park Dams on the...

These images show the Coalcliff and Stanwell Park Dams on the plateau nearly 1000 metres above the coastal mining town of Coalcliff.

I believe the Coalcliff Dam supplies water to the coal mines at the foot of the cliff.

As you can see, the Stanwell Park Dam has been abandoned and allowed to grow over.  I would think it could easily be rehabilitated to become the upper reservoir.

I am thinking there would not be many other places in Australia with as many pre existing components for PHES and so close to a major population centre.