Western Australia is the second driest state in Australia and a lot of people have become very creative about greywater use. 'But' the fact is, short of installing a full recyling system (about $4000) there is no really safe or sustainable way of re-using greywater other than letting it soak away in a septic tank or sending it down the sewer and on to the Indian ocean. Gardening Australia (ABC tv 18.30 Saturdays) is a very useful source for good water recyling tips. Josh Byrne who often has segments on Gardening Australia has his own web site which is really worth a look if you are interested in 'serious money' water conservation
You can also bucket the stuff on to trees, and there are many other devices and creative posibilities or you can use our fully approved niimi trench (only when you purchase a Rotaloo). But be warned if you are not very careful about the vegetation planting as good as the nimii trench is, it will be full of roots within five years. Then it is a case of dig it up and start again! The nimii trench (and several of its pirated clones) are really only good on a blocks 2000 sq M or larger where it can be placed well away from aggressive trees. The nimmi trench design is the only approved system we know of that holds and evaporates the water through the surface and stops the excess nutriton from detergents soaps etc from leaching in to the sub soil and then of course into the ground water that some of us drink!
Instead when you have the opportunity buy low flow shower heads, Front loading washing machines. Some newer dishwashers use less water than washing dishes by hand! - Notably Fisher and Paykel draw units, ASKO, and some Dishlex units. And of course a RotaLoo composting toilet!
Download - the nimii trench plan and reed bed grey water systems