Just to add, I found this on The Law Handbook Online.
It relates to the situation in Victoria. It seems the OC can recover debts under s.49.
https://www.lawhandbook.org.au/handbook/ch10s05s05.php#Ch1302Se257876
Water leaks
Under section 16 of the Water Act 1989 (Vic), a lot owner is responsible for the repair and maintenance of their unit to prevent any escape of water from the unit into any other unit within the plan of subdivision.
Although the owners corporation is not a liable party and need not pursue a response, it must do everything in its power to fulfil its obligations responsibly to ensure that it cannot be implicated in the cause of the leak. This may involve undertaking investigations, repairs and maintenance including new guttering, flashings and sealants and the clearance of storm water drains.
In addition, under section 48 of the OC Act, an owners corporation may choose to be involved and may serve notice on the lot owner requiring the lot owner to carry out the necessary repairs, maintenance or other works and may recover as a debt from the lot owner any costs expended by the owners corporation for the rectification (s 49).