There is no cache at the published coordinates.
To claim this cache you need to complete the Warragamba Adventure Lab. The lab cache begins at the posted co-ordiantes and takes you around the Warragamba Dam.
The cache it's self is located out side of the Dam so can be accessed any time, how ever the adventure lab will only be available between 10am and 4pm while the Dam is open.
The dam is closed on Good Friday and Christmas Day and during periods of Total Fire Ban.