A low-pressure drip water system attached to the wheelie bin gives a passive watering system. I am really pleased this irrigation product (low pressure drip hose) is available. I also avoided buying the wrong type of piping: I went into the store intending to buy the brown version.
The helpful woman at Croydon Bunnings suggested I need a T-joint where the drip pip joins the pipe from the wheeliebin. I followed this advice and my guess is that it equalises the pressure of the flow in the pipes. (The green pipe in the photo starts at the T-joint on the right side)
By using some basic hose fittings, including a small valve and some low pressure drip feed hose bought at Bunnings (AUS $55 ), I was able to create a watering system that really works: every dripper was dripping, and you can turn it on or off easily. The wheeliebin was nearly empty after several hours. If you take a close look you can see a drip coming out of the pipe.
Finally I have figured out the best way to set this system up!
Drippers are inside the pipe every 30 cm (12″)
And the photo at the bottom is the area I am trying to keep alive during this drought, a drought that seems to have no end and seems to be signalling this is the climate of the future.
Photos taken with a Pentax K-m: an excellent intro level DSLR.