Sydney Water requires each lot in a strata plan to be separately metered.
I think that may have been true quite some years ago. Where it’s impractical (or the shareholders disagree), it doesn’t appear to be the case anymore if you read their plumbing guide. There is one block nearby that went through the conversion in the last couple of years retaining single metering which bears that out. Of course the sprinklers, hydrants, stop valve installations there would have made the cost of a few individual meters petty cash.