It used to ± 10% but the ADRs were changed somewhere in the '00s (2006, I think).

Oeck vpn is a better deal than that if you need port forwading. At full price they are expensive but there is a 50% off deal on whirlpool.net.au at the moment. https://forums.whirlpool.net.au/archive/9n1jvqwk US$83 per year, works out to about AU$125 per year.

Oeck vpn allows each user to forward 10 ports and the port number stays the same even if the vpn is reset.

an average of 10 truckloads — each containing 28,000 litres — per week

That's around 1.5 megalitres per year. A much lower number than I was expecting, by a couple of orders of magnitude. Absolutely should be paying for it, though. It's not a world changing amount of water, but it shouldn't be given out freely, especially to such a wasteful use.