"Dirty Water" is another name for using water generated during household tasks such as laundry and baths. It's a water conservation method and it works really well.
The washing machine and bathtub/shower must have alternate methods of draining. One drain going to the septic system or city sewer lines and another directing the used water to either a holding tank or directly on the gardens and a hand switch to make those changes.
The reason for alternate methods of directing the water is because of freezing temperatures and storage capabilities. If routed directly on the garden, it must pass through the house’s siding and will be exposed to freezing temperatures causing the pipes to break. Old homes have the cistern capabilities to hold large quantities of water. These cisterns were for “clean” water or typically rain water not dirty or used water.
Long term storage for dirty water must have a means of preventing bacteria from growing and it can’t be from chlorinated products or it’s no longer dirty water, it’s treated water and will have an adverse reaction on plants. There are pellets you can buy for this purpose. If you’re going to store dirty water, please check out your county extension information or other green on line sites for directions – storage must be done right or it will be a worse mess than drought.
What is “dirty water”? It’s water that has the residue from washing clothes or humans but does not have harsh chemicals. Harsh chemicals such as bleach, electric dishwasher soap, antibacterial soap, fabric softener, bubble bath, and most products with fragrance. Strictly speaking this applies to anyone using a septic system, too.
As far as the residue from baths, showers, hand dishwashing, mop water and washing clothes, if you use a more natural soap, the “dirt” actually benefits plants. If you route water with harsh chemicals directly onto the ground it will either kill important organisms necessary for the sub life of your earth or it will directly kill plant life. Not to mention eventually seeping into ground water. Either use pure dirty water or don’t practice this conservation method.
If you don’t have a big storage facility, route the water directly to your yard by installing alternate drains. Have a lever to turn it from one method to the other as needed and weather permits. In freezing weather, make sure the outdoor drain has been allowed to drip dry. Cover the outlet drain with wire to make sure little critters don’t find it an avenue for home entry. Check that wire to make sure it doesn’t clog with lent and cause a backup of water into the house.
Sounds like a lot of trouble but then most conservation methods require some effort. I will tell you if you are paying a high water bill, are concerned about your use of nature’s resources, or if you are watching your valuable plants die from lack of watering, the trouble and expense of this method is nominal.
Make sure you route the water away from your foundation (like you do with your gutter runoff.) You can even attach a hose to the end if you want to direct it more specifically. Any handy person can install this method or use a plumber if you haven’t the time, energy or talents. Try one appliance (perhaps the washing machine) first and see if it’s a system that works for you.
Getting down and dirty takes on a whole new meaning!