Rainwater Harvesting for Off-Grid Homes

Water may well become more sought after than gold. While a person can go without food for weeks on end, a person can only go without water for a matter of days, so while gold is nice and shelter is important, water is probably our most crucial natural resource. So it makes sense to put in a system whereby you can be assured that you will always have your own source of water. After-all, isn't off-grid living all about independence and becoming self reliant?

What the heck is a water catchment or rainwater harvesting system anyway? Well, it is a system that collects rainwater either from the roof of your home or from other areas usually surrounding the home. It then filters the water and voila you have free, un-flouridated water that you can use like any other water. You can practically throw away those water bills right now!

There are many ways of getting water but rainwater harvesting is by far the easiest and most cost effective way of collecting water. Once the water catchment system is erected it pretty much runs by itself. Moreover, it requires little if any power to use. Additionally, rainwater is more pure than water that has fallen to the ground containing less calcium and minerals and almost always exceeds the quality of groundwater. Another benefit of rainwater harvesting is the avoidance of chlorination and fluoridation treatments.

In order for a water catchment system or rainwater harvesting system to be used as the sole supplier of water there must be approximately 24 inches of rainfall per year. The entire eastern half of the United States as well most of California, western Oregon, Washington, parts of the Rocky Mountains and even parts of Arizona have at least 24 inches of rainwater per year. Moreover, this figure assumes that you are using flush toilets. Water-based toilets use from 1 ½ to 5 gallons of water per flush! If you conserve your water using composting toilets (see my other hub “Composting Toilets”) you will save a great deal of water and may not need 24 inches of rainfall per year.

Most rainwater harvesting systems collect rainwater from the roof. The best roof for water catchment systems is either made with an un-coated stainless steel or factory enameled galvanized steel with a baked enamel and a certified lead free finish. Make sure if your roof is painted that the paint does not have lead in it. Your roof should be away from any trees as birds and leaves can contaminate the water.

The next thing you will want to get is a cistern. A cistern can be very expensive or as cheap as used plastic containers (cleaned of course) and really depends on how big of a system you want. Also, you will want some kind of filter. This too depends on how elaborate you want to make your water catchment system. Some filters are very expensive, some you can make yourself for very little money.

Many people say that you cannot drink rainwater without serious filtering, however according to one study (link is below) rainwater is perfectly fine to drink. After-all how did people live 100 years ago? If you want to be extra cautious all you would have to do is boil the water. I would think a constant tea kettle on a wood stove might just do the trick. Moreover, they have done studies and have found that rainwater is actually better for you than the fluoridated and chemically spiked tap water!

So how much water do you need? I filled out the questionnaire below and my estimated water usage is about 50 gallons a day, or 18,250 gallons of water a year for one person. But according to www.rainbarrelguide.com for every inch of rain that falls on a catchment area of 1,000 square feet, you can expect to collect approximately 600 gallons of rainwater. Ten inches of rain falling on a 2,000 square foot catchment area will generate about 12,000 gallons of rainwater! That’s right, 12,000 gallons! Of course if you are living off the grid you will have to account for your animals and irrigation needs, however if you use a humanure toilet in addition to other things like including well water it sure seems to me that a catchment rainwater system might just do the trick or at the very least cut your dependency on outside sources.. After all most places in the United States have more than 10 inches of rain per year.

So is it possible to have all your water needs met with a catchment rainwater system? It would seem so! Check that off the list!