How much water?

Pete, when you say SOR metro, are you fully suburban or one of the more rural suburban? Places like serpentine, even armadale and kelmscott have allowed bores to be drilled in the past. My grandfather lives in Ellenbrook, which for everyone else is a newish estate area, and he got approval for a bore with no issues.

a compost toilet is an option as well, they use far less water than a normal one and are not the smelly long drops they used to be

I'm talking about a productive homestead. Not sanitation or bugging out etc. Yep we can do with very little water but we should be setting ourselves up so we do not have to. If you're so worried about your water supply that you are worried about flushing toilets or serious recycling then you need to think about having more water.
This is my fourth homestead each in very different climates, at each location I've put enough money and effort into water to not worry about it at all. Although where I am now it's a finite resource it's still ample to grow all our food and raise our livestock.

agree completely wellrouded, however I think minimising your usage is a part of bein a productive homestead. Each flush, even a half flush is 3L, if a family of 5 uses the toilet once a day its 18L, whereas in a flushable composting toilet they use 500mL so only 2.5L usage a day, that amounts to over 5500L a year. While this is not a huge amount overall, being able to save 5500L of potable water a year is nothing to sneeze at.

In saying that, the area I am in has around 300mm of water a year so it is a very low rainfall, and even though there is an ample underground lake, a lot of it is very salty. This is a big issue for the property I am looking at on the weekend as it has access to a bore that apparently has very clean water.

I can't talk about growing food, but leaving that aside I took records for years while we were on the road, over many years we averaged 10 litres per day, for both of us.

That's everything, but with a casette dunny (no flushing) and sparrow washes (no showers). Includes all laundry except large items like bedding that waited until we were camped near a river at which point river water was used for all laundry. So to allow for using river water for laundry when available I would estimate 15 litres per day for two people. Round that up to 20 and you can have water fights as well

Some quick figures.

To irrigate our vege patch (25m x 35m) we use about 900000 l per summer. This is about equivalent to 1000mm rainfall.
Our seven cows drink 350 l per day (130,000 per year).
20 sheep use about 100 l a day (36,500) per year.
2 horses 60 l per day.
Pigs 100 l per day drinking and 100 l for wallows.
Greenhouse and pot area 3000 l per day, this generates our income.
Orchard about 500,000 per year.
Plus water for the gardens around the house.
We also have a 2000 location (drip irrigation) vineyard/orchard ready to plant out. Long term this will grow fruit to feed livestock (apple fed pigs).

It adds up pretty quickly.

Because we grow and make everything here we do a lot of dishes. I probably do 4 to 10 loads of dishes a day, three after meals and then the others for preserving/cheese making/baking/milking/butchering/animal feed making equipment. This is all done with rainwater, our roof catchment is 57,000 l with our roof area. We are about to double it and a bit so will be able to catch more summer rain.
EDIT: corrected a typo 27,000 should be 57,000 l from our roof area.
I work with livestock everyday, including pigs, I want a shower. Even when I've lived rough (which has been often) I still have hot and cold running water. One set up was a 200 l plastic drum filled using an Ideal hand pump from a dam. Then that water filled a header tank sitting on top of a hot water tank, sitting on top of a large stump. Water was heated with an old free standing water jacket type chip heater. Still have the water jacket . Garden hoses then carried hot and cold water down to the shower further down the hill or into the kitchen sink in the tent. I was building a house while living in that tent, everything done with hand tools, no power at all not even a torch. Hot water and a shower at the end of the day was a very welcome luxury.

Thanks for those figures wellrounded, it's amazing how much you need if in the self-reliant homestead scenario. This is the main reason we will never be able to go to the extent you have, we are in a very dry area.

Yes a daily hot shower is something I have missed a lot

Historically about 900mm pa, I think I have figures for about 2000-2010.

Essentially no surface water anywhere, certainly not on my land. Bores are pretty common though but we don't have one.

That's twice our average rainfall and three times what we've been getting lately.