What is The Cheapest Way to Collect Rainwater

When the spring and summer months approach and the average household demand for water increases more than 40%, for outdoor gardens, lawns, and maybe preparedness,  A 1000 square foot roof can capture more than 20,000 gallons of free water. What is the cheapest way to Collect Rainwater?

The Cheapest Way To Collect Rainwater Is To:

  • Buy a 55-gallon FDA Food Grade Plastic Drum
  • Add a spigot to the Drum or use a Siphon.  
  • Construct a Platform for The Drums
  • Set in Place on a Platform Under Your Roof’s Gutters
  • Buy a Downspout Converter that will drain rainwater into the plastic drums

During the summer months, homeowners live mostly outside and spend a lot of time cleaning up from the winter and watering lawns and gardens  During summer Draughts, when water is restricted, harvesting that free resource seems like a perfect solution.


Rainwater Harvesting Method


Choose the area where the main roof collects the most water and where you will have the best access to stacking and moving the rain barrels. You can link drums together to add more barrels by simply staggering the height of each drum and connecting them with a plastic hose in series. Gravity fills the first then the next one in sequence. Look at the picture at the top of the article. it’s very easy just to use separate platforms heights for each drum.


Pick a 55 Gallon Container

If you are storing the water for an Emergency: You need to pick up an FDA-grade Food Grade water storage BLUE container that will last up to 5 years. Each drum has 2 bung holes at the top that will accept a barrel pump.

These barrels are made of High-density Polyethylene UN-DOT-certified plastic can that is made to store liquids.

The drums are pressure tested and leakproof and come in 15-30-or 55-gallon capacities. Cost Approx. .$79.00-$99.00 or recondition used for about $49.00 or half the price of a new one. Blue is coded for drinking water. In the event of an emergency, it won’t be confused with any other kind of liquid. Or more with the whole Kit.

In a survival situation or for disaster preparedness color codes are used in identifying chemicals and liquids that are in store in containers. It’s a good idea even if you are using it now for the garden.


How to Build a Rainwater Collection System


Next is a platform for your water drums to sit on. A cinder block makes for a safe reliable flat surface but there could be some corrosive material that is added to the blocks when making them. This could harm the plastic drum if it’s sitting in one place too long.

A piece of thick pressure-treated plywood on top of the bock and underneath the barrel will separate the plastic from the concrete and should ensure that it lasts a long time. The barrel will be standing up which is the proper way to use or store them over periods of time.

You can run the barrels in series to take advantage of the free resource and fill more than one barrel at a time or a bigger holding tank. This is another easy project. Your platform would need to be bigger to accommodate more barrels.

So decide if you want to add another barrel in a series later just extend the platform and add and connect the barrels at the bottom, so when the first barrel fills it will move the incoming water to the second then the third then so on. Some people will fill one barrel add a Water Preserver Concentrate that will treat 55 gallons of water and store the drum for up to 5 years in a cool dark place like a garage.

If you decide to store rainwater for emergency situations and potable water supply then you’ll want to chlorinate the barrel like you would for a Drinking Water Well or new water line. You can do this by

*adding a half cup of bleach to the drum and then rinsing it out with the garden hose to purify the container.

*The gutter can be screened at the top where it enters the downspout and then at the point where it enters the drum

* Use a coffee filter to pick up smaller materials. No matter how clean the rain is, the roof will have some dirt on it.  So before the water gets to the drum you can filter the bigger debris that washes off.

*If your water is being used for the garden and lawn then you might not need to do this at all. It all depends on how you will use the water.

If you are going to drink the water, there are new water filtration products that are remarkable, especially the ones that are gravity fed. They can remove just about anything organic along with chemicals. If you can keep organic material out by screening the water before it is stored in the drum, it will be advantageous down the road.

Once the barrel or barrels are full you should close them up and store them in a building like a garage or an enclosure. The water barrels have 2 fine threaded bung caps with 2-inch openings with a 3/4 ” knock-out at the top of the barrel one side for a vent and the other for a pump or siphon.


How to Collect Rainwater for Drinking


That’s a question for you to answer. The condition of the roof is a factor in the materials used.  Is it a metal panel roof? That would be the best scenario. More importantly, what treatment will you use before you consume it? Drinking water is tested for suitability as a Standard that is used Nationally. In a survival situation, you may have to settle for a little less.

It’s a known fact that humans can go 30 days without food but only 3 days without water The urgency that it brings to a situation like a disaster makes drinking water the most important element for survival. I would trust myself to make a decision on whether to drink from the rainwater that is stored in the garage.

At the very least use the harvested rainwater for a Kitchen Hydroponic or garden that is producing food that is sustainable. Some people worry too much about what they put in our bodies and that’s a good thing, sometimes but in a critical situation those things won’t seem so important.

Water filtration technology has produced incredible portable filters in the last few years that work off gravity. In the event of a power outage or disaster, water will always be the main issue. New Gravity Filters Like Berkey Water Filter down below need no power or plumbing to work.  I have a 2.25 gal. Berkey is at home for my family. They use the newest most powerful technologies to remove viruses and bacteria and any chemicals that make their way into your drinking water.

The filter life depends on how dirty the water is, to begin with. Rainwater can be polluted by cities emitting byproducts through certain industries. So the farther you live from a city most likely the cleaner your rainwater is. Another factor would be the roof delivering the rainwater to the barrels. A medal or PVC panel would naturally be a little cleaner but there might be some bird poop that eventually finds its way into the barrels.




 The Rain Water Downspout Converter

The Downspout Diverters are designed to close or open for manual operation. They are great for starting your Rain Harvesting operation from the best source of rainwater, your roof.


JimGalloway Author/Editor

Related Questions:

In what states is it legal to collect rainwater?  Most states do not have rules on the books.  Ten states have rules specifically allowing the unrestricted collection of rainwater. Only four states have specific restrictions against collecting rainwater: Arizona, Colorado, Oklahoma, and Utah.

 Can you drink rainwater?   Can you drink rainwater? Most rainwater is safe to drink. Actually, rainwater is the water supply for much of the world’s population. The levels of pollution, pollen, mold, and contaminants are low possibly lower than your public drinking water supply.

Can you purify sea water to drink? Can you purify sea water to drink? No Humans cannot drink saline water. That may seem as easy as just boiling some seawater in a pan, capturing the steam, and condensing it back into water which is called (distillation) water treatment.




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