In an effort to reduce my water usage and improve my vege garden I'm currently focussed on rain water irrigation. I've also thought about using gray water (from washing machine and bath/shower) but have decided to start by focusing on rain water. There is so much rain water available here (all year round), and it involves far fewer Council regulation hassles when used only for watering the veges, that it make sense (at least to me) to start with rain water.
In December 2007/January 2008 I installed 4 1000 litre rain water collection tanks behind the garage. Those connect up to a garden tap, which I use to fill water cans for watering the garden. This summer has very dry so our intermittant hand watering hasn't been enough for some of the veges. That lead me to want to install a drip irrigation "system".
In March I connected the garage tanks up to the 200 litre tank I'd installed on the south side of the house 2 years ago. I've been using this tank to water the fruit trees in the front yard.
One of the nice effects of this should be that I am now collecting from three roof faces (2 sides of the garage plus 1 side of the house) into the distributed rain tanks.
I'm contemplating the 200 litre tank with another 1000 litre tank on the south side of the house - but the lounge windows look out in that direction (the 1000 litre tanks are petty ugly in there steel wire cage). I need to mull that over a bit more.
Over the easter holidays I added a hose out to the lemon tree in the front yard. Unfortunately... I forgot about it till the next day. By that time all 2000 litres from the garage tanks had quietly dripped under the lemon tree. Doh! So now I'm desperately hoping for another good solid rain like at the start of the month.
It's a renewable resource
A week later we had a good day of solid rain which refilled my tanks with 3000 litres of rain water.
Early April 2008
I've installed irrigation drip tape over half the rear vege garden. The tape is second hand from my in-laws who ran a small flower growing garden. They've since switched to avocadoes - which require less ongoing effort (and less drip tape).
Mid April 2008
I've buried irrigation pipe under the right front yard all the way to the front fence. There's now a dripper on the apple tree. I'll do the others next.
Late April 2008
Have started work on install a 200 litre tank under the grape vine to provide water for the seedlings table over the old BBQ. This tank will be filled from the guttering above the deck. I'll create a frame to hold the 200 litre barrel horizontally so that I get the best available pressure.
I've stalled on the irrigation front - July was a very wet and wild month so I didn't really feel like much about in the mud.