Eastern Water Skink
Eulamprus quoyii

These are large Eulamprus skinks, related to the Alpine Water Skink, but larger at 11.5 cm from snout to vent. They are common down much of the NSW and Queensland coasts but endangered in Victoria. As the name suggests, they can often be found near water and will dive in if disturbed.
 

1-2: Hornsby, NSW, 05/10/2010.
3: Bicentennial Park, NSW, 20/09/2010.