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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 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.

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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!

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Brie Hoffman (author) from Manhattan on July 06, 2012:

You are so right "SantaFe outlander", thanks for commenting.

SantaFe outlander on July 06, 2012:

here, to go with my prior comment:

this is how the third world is doing it. Ferrocement catchments.

SantaFe outlander on July 06, 2012:

Our town in the SW is limiting each household's water consumption to 4-5,000 gallon per MONTH, due to the long term drought for the region.

I have a family of six ... and we use just half of that limit. It's unbelievable how much water so many folks believe they need. We must have cisterns if we wish to ~legally~ maintain our gardens ... and many do here.

Is it really necessary considering the planetary realities to wash cars, water lawns, bathe twice a day? ... to pee in a toilet? Perhaps the inconveniences of the recent east coasts weather events have a much deeper, and quite necessary meaning. 11,000 gallons per month? Good luck with that.

Brie Hoffman (author) from Manhattan on October 06, 2011:

Thanks Nathan, I corrected the error on the article. You have to remember that that amount was using 10 inch rainfall measures..most places in the U.S. get more than 10 inches of rain per year.

Nathan Bl from Ottawa, Kansas on October 06, 2011:

I love the article and I agree that water collection is very important. The only issue I have is a problem in your math. 365 X 100 = 36,500 not 3650. so 6000 gallons is not going to be adequate for 1 person per year at that rate of consumption. If you were able to conserve and ration water usage back to 16 gallons per day, then a 6000 gallon cistern would work for one person alone.

The Jet from The Bay on April 15, 2011:

Yes -- and, of course, that.

Brie Hoffman (author) from Manhattan on April 14, 2011:

Or...if the corporations steal all our water instead of just some like they are doing now.

The Jet from The Bay on April 14, 2011:

This will be quite useful if there's ever a zombie epidemic. Thank you for this.

Brie Hoffman (author) from Manhattan on March 30, 2011:

Wow, that is fantastic! I'm jealous!

Jean-Paul Simon on March 30, 2011:

My whole home is pressurized by gravity. I live in the Pacific NW, and while I don't catch rainfall, my home is fed by a natural spring. The spring source is only 16 ft higher than the house, so I use a series of non-electric water rams to slowly 'pump' 44 ft uphill to 3 10,000 gallon tanks. The pressure from 60 ft is enough to pressurize my home at 39psi (3bd 3ba) as well as power the elevator- or dumbwaiter if you're a zoning inspector.

Brie Hoffman (author) from Manhattan on March 17, 2011:

Thanks Crystolite.

Emma from Houston TX on March 17, 2011:

Yeah,Am never surprise that this smart article is really coming from you,Brie.thanks and is nice reading from you again because i have noticed you have a lot potentials in you and also writing is not now a hobby but part of you.kudos.

Brie Hoffman (author) from Manhattan on February 19, 2011:

And it really isn't expensive to set up at all! Sure, do it this week! Good luck to you.

shawna.wilson from Arizona on February 19, 2011:

I just looked at our past water bills, and our average monthly useage is about 11000 gallons. So I guess rain water harvesting would save us half a month's worth or so. Thanks for the info!

Johnnydowney on February 19, 2011:

Great idea.

I think it is high time that rain water harvesting is made compulsory for every home.

Brie Hoffman (author) from Manhattan on February 18, 2011:

Yup, the worse state for rain...I do believe. Still 10 inches of rain per 1000 sq foot roof will give you 6000 gallons, that's quite a bit and it definitely would make a dent in a water bill.

shawna.wilson from Arizona on February 18, 2011:

I'm in Arizona. On average, we get less than 10 inches of rain a year :(

Brie Hoffman (author) from Manhattan on February 18, 2011:

Thanks sci334 I hope you voted it up!

slc334 from Canada on February 18, 2011:

This is a really great article, I plan to put some of this to work this summer! Thanks for your hard work.

Brie Hoffman (author) from Manhattan on February 17, 2011:

I'm so glad you like it...I'm hoping to do an article on delivering the water to showers without electricity soon.

Fran Hafey from Virginia, USA on February 17, 2011:

Hi Brie, I love this article, lots of great information. We have our house gutters going into a large water collection container/tank and I collect water in smaller containers in other areas too in barrels to water plants and our garden in the summer. I totally agree with you about how water will be like gold one day! We're lucky to have a good well, but we always save our water and use it wisely. We even use ice and snow in the winter, bringing it in the house and using it for watering indoor plants and on our wood stove in a pot for humidity, of course after its melted. :) We're looking forward to living off the grid, soon! Thanks for a great article.~Mysti~

Brie Hoffman (author) from Manhattan on February 17, 2011:

Where are you?

shawna.wilson from Arizona on February 17, 2011:

This is great information. I wish I could take advantage of something like this, but we don't get enough rain.

Brie Hoffman (author) from Manhattan on February 15, 2011:

I'm so glad...also if you can raise those tanks you wont need electricity to deliver the water to your house...just a thought.

Cedar Cove Farm from Southern Missouri on February 15, 2011:

Very informative. I have been contemplating a couple of tanks on the back side of my barn. You have given me the incentive to go ahead. Thanks.

Brie Hoffman (author) from Manhattan on February 09, 2011:

I'm trying to figure out how to use gravity so that you can deliver the water to the house w/o a pump. Thanks for writing.

JD Barlow from Southeast US on February 09, 2011:

Great hub! I have been thinking about building a water catchment system, thanks for the information.

Brie Hoffman (author) from Manhattan on February 08, 2011:

I was surprised as well...I think (and I have to look into it further) but I think if you built a system on a hill you could use gravity for showers, tap water, everything and it would be completely free after the initial set up. I tried to find someone who did this but wasn't able yet. Thanks for commenting.

rpalulis from NY on February 08, 2011:

Such a smart idea, I was planing on building gravity self watering system for my gardens and green house using this method. It's amazing how much water you can collect this way.

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