I am in Bendigo, Victoria, a state within Australia.
I have experience with the subject matter.
It is not about managing people, not is it about water.
Its simply to prevent large productive land being broken down into hobby farms.
In Woodend, not farm from my place, the most productive land in the area is now 5 acre blocks. Its a disgrace.
I am surprised to see you suggest
Now we don't need a permit to build a building with less than 200square metres floor space
In Victoria it is 9 sq M.
Depending where you are looking at, that must be limited because the soil type you are looking for is hard to find, the ~Shires have different
attitudes about things.
Building a small 'farm' shed for equipment usually gets through.
After inspection if do do it legal, you add amenities.
If you keep it simple like a camp site as I did for 20 years I doubt you will have problems.
There are many other things to consider;
- water storage
- shelter belts
- fire equipment-
-security of items
- fencing.
Good luck with it.