Rainwater is a free resource and it is collected by many homeowners across America. Those of us who decide to harvest rainwater can gain thousands of gallons of free water with a little effort and just a few dollars.
One of the best sources to collect rainwater is your roof. When rainwater falls onto the roof, it rolls down the sides of the roof and into the gutter and spout system. Instead of allowing that water to fall through the gutter and spout, onto the ground where it is eventually absorbed in the ground, catch the rain and save it!
The most basic way to save rainwater is with some tubing and an old barrel. Of course, catching rainwater can be much more elaborate but the simplest system involves a pipe and a storage vessel of some type. The photo below shows a very basic set up and was our first rainwater “system.” This rainwater catchment system was a pipe straight from the gutter off the roof into a rainwater barrel:
Living in the country, we are on a well. Although our water is free, we must use an electric pump to supply our home with our well-water. We have always been careful with our water usage, despite having natural springs and a stream on our property.
During summer months, we are vigilant with our well-water usage — especially during hot, dry spells. Having a quantity of usable rainwater at our disposal is very handy during these times. Not only does the harvested rainwater provide all of the water for our garden irrigation, but having an ample supply of rainwater also helps to provide our property with a passive hydration system in and around our living quarters. And if, for some reason, we were forced into a grid-down situation, our collected rainwater could be used for a variety of household water needs.
Collecting rainwater is a very simple process, but be forewarned: Rainwater is usable water for irrigation purposes only. Rainwater collected from a rooftop is not potable water, as it contains minute contaminants from the collection system. We do not drink this water, nor would we recommend you try it either — unless it was a life-or-death situation and the rainwater was filtered, and then boiled (possibly even treated). We also do not recommend that you use rooftop rainwater for your livestock, but again, if faced with a life-or-death situation, collected rainwater could be filtered and sanitized for use.
Rainwater Catchment Systems
Simple rain barrels made of recycled food-grade plastic or polyethylene can store between 50-55 gallons of water each. Buying a rain barrel costs about $50-$100, but a recycled food-grade rain barrel is an inexpensive purchase. Sometimes food-grade barrels are offered for free.
To harvest rainwater, cut a hole in the top of your rain barrel, then situate the barrel at the base of the roof downspout. Depending upon the length of your downspout, you may need to remove a section of the downspout. If you have a downspout on each corner of the roof/house, place a rain barrel under each. This is the most basic rainwater catching system that any homeowner can accomplish with little cost and effort. Our original rainwater catchment system looked like this:
Sophisticated catchment systems have gutter pipe-connected rain barrels (a barrel system) or a very large cistern-style water tank to hold much larger quantities of rainwater. The large cisterns are often above-ground and can hold from 500 gallons to thousands of gallons of water. Some of these large cisterns can even be buried underground.
Our total rainwater catchment system is for 1,500 gallons of rainwater. Our system includes an installed livestock tank that holds 1,100 gallons and this photo shows the tank shortly after we installed it. Prior to installation, we prepared the base area with sand, then leveled it. And since the tank is unsightly, it’s now hidden from view with a tall fence.
The stored rainwater can be used by attaching a hose to the tank’s base using a shut-off valve that we installed. When we need to use the rainwater for our garden, we open the valve and water is gravity-fed via an attached garden hose. We keep rainwater throughout the Winter season so we insulate the bottom valve to prevent freezing.
With a small rainwater system, an inexpensive underwater bilge pump can be added, too. Although many pumps are electrically-dependent, they offer a means to pump water out of the rainwater system. An underwater pump is required if there is a problem with gravity-fed water release, so keep this in mind if you are interested in collecting rainwater for garden use.
Our old rainwater collection system began as a system of several recycled food-grade barrels. As our water needs increased, we added to our barrel system, connecting the barrels with PVC piping. Using a submersible pump, we were able to harvest our rainwater for our gardens.
Determining the potential rainwater harvest, compute the following:
With 1-inch of rainfall, the yield is approximately 600 gallons of rainwater for every 1,000 square foot of the collection area.
An average home of 1,500 square feet of roof, using rain barrels at each corner downspout, has the ability to collect 900 gallons of rainwater per inch of rainfall. To determine the yearly rainwater yield, multiply the 900 gallons by the average rainfall in your region. Isn’t that an incredible harvest?
Now what’s stopping you from collecting some of your own rainwater for your own gardens?