The whole emphasis of this website is graywater gardening.
Therefore, the purpose of a graywater irrigation system is to enable the garden to make the most of the available water.
Previous technologies such as leach fields are designed to disperse the graywater in the most effective way, rather than optimizing the take up of water by plants. Graywater irrigation systems are often used as a method of dispersing graywater to reduce septic load, but this is not a focus of this website (in any case we believe a dispersal system should focus on maximizing plant growth as this is better for environment).
Because graywater is available every day (if shower graywater is accessible), it is important to understand how daily irrigation affects irrigation - it is very different to watering twice a week.
Please read 'Irrigating every day' before reading about individual techniques.
Further information about Irrigation Methods
Irrigating every day
Buckets and hoses
Laundry to landscape
Pumped hose / nozzle