Sydney Water has explained the reason for the signs about sewage overflow in the Boneyard area:

"A wastewater maintenance structure behind 50 Cathedrial Rocks Avenue was found to be overflowing as the pipeline was blocked. The blockage was cleared and the area immediately cleaned.

"Relevant authorities have been notified, and signage put up to let residents and community know to stay away. As soon as the testing of the waterways is clear, the signage will be removed.

"Sydney Water apologises for any inconvenience caused while the clean-up is completed. We'd also like to take this opportunity to remind the community to only flush the three P's down the toilet and wastewater system - Pee, Poo and Paper (being toilet paper!)."