Greywater is any water that has been used in your washing machine, shower, or bathroom sink that is re-used again to irrigate plants. Put simply, it is getting two uses out of a single volume of water (50 gallons to wash clothes and then 50 gallon to water trees equals 100 gallons of use, but with only 50 gallons of water used!) Greywater systems do not need to be complex or expensive. In fact, we encourage you to keep it simple, work with gravity, and start small. Simple systems tend to be inexpensive and easy to install. Below you will find an overview of some simple greywater systems.
Landscape Direct Systems:
Sometimes the easiest way to install a greywater system is to move the water outside rather than altering your indoor plumbing. Typically, there is no permit needed as this not considered indoor plumbing.
Need a place to wash veggies from the garden or clean up your hands? Consider installing an outdoor sink hooked up to an outdoor spigot. Set that sink up next to a tree and every time you wash your hands or veggie harvest, you are watering the tree.
San Diego has one of the best climates on earth and what better way to enjoy it than to shower out in it. If it is too cold in the winter, just use it in the summer when the temperature is hot, the weather is dry, your plants need a drink, and you really need a shower. An outdoor shower can be as simple as a hose with a shower head dangled over a tree of your choice. Or this could be something a bit more permanent, decorative, and comfortable. The choice is up to you.
Rather than having your washing machine water go down the drain, try tapping this perennial spring and using it to water a few fruit trees. The washing machine is one of the cheapest and easiest systems to install. Below are a few ways to use the washing machine.
One simple laundry greywater system uses a 55 gallon barrel with a hose connected to it. To install this type of system, you can simply move the discharge hose coming out of the back of the washing machine to empty into the 55 gallon barrel. This barrel is not a storage tank, but merely a vessel to absorb the surge of water. The hose coming out of the barrel can be moved around to where you need to irrigate.
Laundry to Landscape
The Laundry to Landscape system is one of the most versatile and user friendly systems around. It uses the built in washing machine pump to move water around to 5-8 different trees with no hoses to keep moving or tripping over. Imagine washing your dirty clothes and automatically irrigating some oranges, limes, bananas, avocados, or other fruit trees.
Branched drain systems
The branched drain system is a gravity-based system that sends greywater from showers, laundry and/or sinks to the landscape using standard 1.5” or 2” drain pipe. The irrigated area must be lower in elevation than the greywater source. A downward 2% (1/4″ per foot) slope must be maintained at all times. The greywater is divided, or “branched” using a double flow splitter, and the final outlet of each “branch” irrigates the root zone of a plant inside a mulched basin. Branched drain systems are best suited for trees or other large shrubs. This kind of system can be time consuming to construct, but once complete requires little maintenance and is long lasting with no moving parts to break.