In 2016 I created a short-lived cache by the #2 reservoir but it was a terrible hide and I voluntarily archived it when it seemed to be missing when doing a maintenance check.
This cache is more traditional hide with a proper container in the nearby trees. Getting to the reservoir is an easy walk on a well formed track. Some minor clambering may be required at the cache location itself which is why this is a T3.5 on an otherwise T2 route.
Getting a reliable GPS fix here is somewhat challenging and the published coords are a result of 2 sets of 10-minute averages on different days. Your GPS will undoubtedly disagree by up to 10m on any given day so I fully expect the hint, terrain rating and cache size to be important parts of the searching strategy.
Note that dogs are not permitted in this area. Quoting from the PCC web site:
Dogs are permitted off lead, but only in the exotic trees. Dogs are not permitted on the route up to the reservoirs which travels through native bush on the adjoining DOC scenic reserve (Colonial Knob).