Welcome Bentan!
I consider myself a hobbyist, but that is restricted only to 725 sq ft (67.35 m2) of backyard land,
We are a diverse group here, Most of us have backyards in the city lots where we do our hobby on very pricy piece of dirt, but very few have a "backyard" as big as yours! Some of us own greenhouses and some own whole small island in the tropics. Majority of us do drip irrigation.
It is a real challenge when you have limited amount of rain, especially with the current global climatic change where Australia is mostly impacted.
Here's some useful links to a department from my Alma Mater:
http://www.sarep.ucdavis.edu/
I think I have encountered various approaches to farming in very arid climate like yours when I took some graduate courses in sustainable agriculture. There are too many to mention so in laziness, I just provided you the link.
So how much rainfall do you get? Over here in Northern California, we averaged about 51 cm each year. But the state has sophisticated and complex water capture and delivery system.