I live in the last of a line of town houses on a strata property (i.e. there is an owners corporation) in Victoria. The sewer that services all the town houses passes through my back courtyard and then into the main public sewer. There is an inspection opening (IO) and overflow relief gully (ORG) for the common sewer in my courtyard.
I was away for a few weeks and when I returned, I discovered that the common sewer was overflowing through the ORG into my courtyard due to an object becoming lodged in the common sewer pipe. This was not happening when I left to go away (I regularly pass through the courtyard, so I would have noticed). I'm unsure where the object came from, but it's unlikely to have been from my sewer, given that I've been away.
Who is legally responsible for paying the plumber's fees for unblocking the sewer – me or the owners corporation? Any advice would be really appreciated.