Grey Water: What It Is and Why It’s So Important

Water is widely understood to be one of the greatest survival needs. Most survival teachers state that you need one gallon of water per person, per day for drinking and cooking. Unfortunately, many have taken that to mean you need one gallon of water per person, per day to survive. This is a mistake. We use water for a wide range of things, not just drinking and cooking. Many of those are necessary for survival as well, especially long-term survival.

If all we’re talking about is a short-term disaster, you can get by with one gallon per person, per day. But preparing to survive only a short-term situation isn’t wise. There are many events that could lead to a long-term survival scenario. For those, you need to consider other uses for water.

Specifically, the highest additional priorities for water are cleaning and growing plants. I’m not talking about the lawn in front of your house or your flower garden; I’m talking about plants which you are growing to eat–a vegetable garden. You don’t need purified water for that. In addition, keeping your home clean is necessary to help control sickness and disease.

In a long-term survival scenario, you’ll actually use a lot more water for cleaning and watering your garden than for drinking and cooking. So water management should be a major part of anybody’s long-term survival plan.

What Is Grey Water and How Does It Fit In?

One of the best ways to manage water use is to reuse it. In reality, there are few uses of water that require it to be purified. We only need purified water for drinking and cooking. Everything else can be done with either unpurified water–such as you would get out of a pond–or water that has already been used.

Used water can be broken down into two separate categories:

• Black Water – This is sewage from the toilet. It can’t be used for anything else, but must go into a septic tank or sewage system.
• Grey Water – This is water that has been used for cleaning. While it isn’t clean enough for drinking, it can be used for other purposes.

The vast majority of the water we use in our homes actually goes down the drain as grey water, not black water. This means we’re essentially wasting that water. In a survival situation, where water is limited, we can’t afford to allow any water to go to waste.

What Can We Do With This Grey Water?

There are a myriad of ways in which grey water can be used. If you go back in American history, families bathed once a week, especially on the frontier. Of course, that was when they were drawing water from a well with a bucket and heating it on the stove; so filling a tub for bathing was a big job. Since filling that tub took so much time and effort, everyone used the same bath water, starting from the youngest in the family and working their way to the oldest.

In a survival situation, where water is valuable, you will want to develop strategies similar to this. While water used for cleaning can only be used so much, most of the time we end up throwing out water that has not been used as effectively as it could be, especially bath water and water used for washing clothes. Using that water to wash additional things, such as additional family members, your clothes, your dishes and your kitchen can help it go farther. Then, once you’ve washed everything you can, the water can be poured into your garden rather than down the drain. That way your plants can benefit from it as well.

Many people have expressed concern to me about using soapy water for their vegetable gardens, but I have had the water from my kitchen sink and my washing machine supplying water to my vegetable garden for quite some time. It has not affected my plants in any negative way, including the taste of the vegetables.

One last use for this water, if you can’t find anything else to do with it, is use it to flush your toilets. Water that goes down the toilet can’t be used for anything else, and it really doesn’t need to be clean. Simply pour a bucket of grey water into the toilet bowl to flush it, rather than using the lever to flush using the water in the tank.

This is actually rather common in third-world and emerging countries, where their toilets may not even have a tank. All you’re doing is replacing the tank and flush mechanism with the simple expedient of using a bucket. It works exactly the same.

Making it Possible to Use Grey Water

The biggest problem most of us have with reusing grey water is that our homes are not designed for it. Every bit of water we use is flushed down drains, either into septic tanks or into city sewer systems. This is wasteful, both on an everyday basis and especially in a survival situation.

Ideally, you would want your grey water to empty into a tank where it can be collected for use. However, this requires a major re-plumbing of your home, which might be against your local building code. However, there are some things you can do yourself, or with the help of your local plumber, which are fairly easy and make it possible to reuse your grey water.

Let me say that this is easier if you have a two-story home. As drain lines are gravity fed, you can readily divert them from an upper story much easier than you can divert them from the ground floor. However, it is still possible to use some of the grey water from ground floor rooms.

The key is locating where the water pipes are. This is easier than you might expect. Simply look at the drains for things like your kitchen sink, bathtubs and your clothes washer. Those will go down inside the walls to the home’s central drain point. In many cases, those drain pipes will be in exterior walls. That’s ideal for what you want to do.

With any drain pipe located in an exterior wall, all you need to do is cut a hole in the outside of the wall, cut the pipe and install an elbow. Then you can attach either an additional pipe or flexible tubing to this elbow and have it lead to your vegetable garden or to an outside grey water tank. I have done this with the water from both my washing machine and my kitchen sink and am using it for my garden.

Water from bathtubs can be reused directly while you are bathing. Simply put your dirty clothes in the bottom of the tub with some laundry detergent, and walk on the clothes while you bathe. As you “stomp the grapes” as if you were making wine, you will wash those clothes. Then, after that, the water can be left in the tub and used to flush toilets. All you need to do is place a bucket in the bathroom.