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PERMACULTURE: Repurposing Household Water

By Mary 'Klibs' Dralle, for Let’s Talk Plants! February 2024.

WiX stock photo.

Repurposing Household Water

The second most important element on Earth is WATER. It is needed to keep everything alive.


On average, the annual rainfall in San Diego County is about 10 inches. This is our first source of water and as per, one inch of rain falling on one acre of ground is equal to about 27,154 gallons and weighs about 113 tons. An inch of snow falling evenly on one acre of ground is equivalent to about 2,715 gallons of water.


This is great for the native plants. For homeowners, we have been led to believe that the water should be sent back to the ocean via storm drain systems and not harvested.


What can be done?


If property allows for it, set up swales, a berm/basin on contour, that are planted on the front side. They are a great way to hold the water in place and grow food as shown in this illustration from


Another way to collect water on your property, when municipal ordinances provide, is to set up rainwater catchment systems using tanks from manufacturers like Bushman USA. They can be above ground or in ground systems.


This photo is an installation in the Texas Hill Country by Rainwater Collection Concepts out of Bulverde, TX. There are six 530-gallon Slimline Rainwater Tanks that capture up to 3,180 gallons of rainwater from the roof of this building. The water can be utilized in the food garden when there is no rain.


This is an example of a 10,000-gallon inground tank when you have several sources of rainwater for the catchment.

A prominent leader in rainwater harvesting is Brad Lancaster. His catch phrase is “turn scarcity into abundance!” He lives in Tucson, AZ. What started out as illegal cuts in his curb to harvest monsoon rains coming down his street, has turned into city ordinances on how, and where, to make proper cuts to allow for the flow of water around parked cars into swales! Many useful ideas can be found in his books, YouTube videos, and his website,


And there is a third way, as well!


In the mid 1970s, we had a drought and a fair amount of water rationing. In our Olivenhain home, we had flow restricted shower heads, turned the water on and off in the shower and collected that shower water to be used on the trees in the orchard.

My dad said that “one day, this would be standard practice.”

Those days are here now.


In every home across the nation, there are two water byproducts, black water and gray water. Black water is generated in the kitchen sink, dishwasher, and toilet. All have the potential to grow harmful bacteria if left unattended. They should be sent along to a septic system or a municipal sewage treatment facility to be properly treated.


Gray water, on the other hand, is any water generated in the bathroom sink, bathtub or washing machine. All three sources can be sent along to a prepared garden, preferably a fruit tree orchard, shortly after use. Plumbing can be set up to alter the flow from the sewer pipe to a garden supply pipe via a diverter valve. If that is not possible, it can be captured in a bucket under the bathroom sink, pumped out of the tub into a vessel, or collected in a designated 55-gallon wheeled plastic can from the washing machine. In all cases, the soap must be glycerin based as it is biodegradable and nontoxic.


Let's calculate the gray water generated in a day.


Washing your hands or face with the water running uses about four gallons. Turning the water off saves three gallons, using only one gallon each time you wash up. If you use a thin stream of water that amount can drop to less than one quart. Side note: One of the first experiments in any chemistry lab is to prove out proper rinsing. Using three small aliquots of rinse solution works far better than one big large one based on the equation of C1V1=C2V2.


According to the EPA, the average shower lasts about eight minutes. Since the average showerhead has a water flow of 2.1 gallons per minute, each shower uses more than 16 gallons of water. However, if you use flow control to turn the water off it can be cut down to as little as four gallons. That is enough water to keep an established fruit tree alive for a week to week or so.


As stated on their website,, the average number of gallons of water per load for a washing machine is as follows:


No. of gallons of water used

Top-load washing machine with agitator


High-efficiency top-load washing machine


High efficiency front-load washing machine


 This would be our water use in a day:


No. of gallons of water used

Hand washing 16 times at a rate of 1 gallon per washing


One shower - turning the flow off and on


2 loads of laundry in a top loading machine


This would add up to about 62-64 gallons. An average ten-foot-wide fruit tree uses about five to ten gallons each week. If it is under planted as part of a fruit tree guild, the water would be held in place by the other plants and all of the gray water could be utilized on about five to six trees.

Much of this information can be found in Art Lugwid's books including Create an Oasis with Greywater. Since the 1980s, he has designed the proper use for gray water for homeowners and cities. “He has worked professionally on building codes in three states. His quantitative analysis of the health risks of greywater cleared the way for more rational regulation of greywater in California, and he played a major role in the crafting of new greywater standards in 2009 and standards for monolithic adobe building in the 2021 International Residential Code. Art also spearheaded the introduction of a bill legalizing research on sustainable building in California.”  Quoted from his website,


It is always a good time for us to have a think about sourcing our water and setting about changes in and around our homes. We do live in a semi-arid desert and the more people who move into the county, the more important it is for us to have backup sources of water. Personally, I catch and reuse much of the gray water in my home for outdoor use.


A couple of years ago, my kitchen sink would not properly drain. I removed the u-joint, slid a five-gallon bucket in place and used the water to force flush my toilets as I did not have time to call a plumber. This is a black water to black water use that I still utilize to this day. An added benefit is carrying the water to the bathroom exercises my abdominal muscles and strengthens my spine. It is a win-win-win situation!


One last comment, is it greywater or gray water?


When I was growing up, my dad was a stickler for grammar. Grey is actually someone's name, General Charles Grey, to be specific. He was an Earl and Prime Minister in the UK. Earl Grey tea was most likely named after him. It is the black tea, that some enjoy, flavored with oil of bergamot. This is an oil distilled from the rinds of the bergamot orange. While it is common to use the words interchangeably, it is better to call it gray water as it refers to the color of the water and not the flavor.


Until next time, keep those hands soiled.


Mary 'Klibs' Dralle

Certified Permaculture Designer, The Dancing Raven Ranch & Retreat Center

Chef, Cookin' with Klibs Presents the Chemistry of Cooking,

Labyrinth Coordinator/Builder, The Wander-Full Labyrinth Walkers

Follow me on Facebook, LinkedIn & Meetup




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