This is the relevant NSW government page about this. https://www.nsw.gov.au/housing-and-construction/rules/connection-and-supply-of-water-to-rental-properties#water-efficiency
If you’re in NSW, you can’t charge a tenant for water unless your property meets water efficienty measures. “The landlord must be able to demonstrate that the relevant taps, shower heads and toilets in the property meet water efficiency measures.” I don’t know how you demonstrate that without a compliance report of some kind, unless you have the means to measure these devices yourself. If I were the property manager, I would ask for a compliance report. Or you can do what I do and just pay for the water yourself (and claim it as an expense on your tax return).