Collecting rainwater for your garden…it’s sounds pretty simple doesn’t it? Well, it can as simple or as complex as you make it with a little planning. One-third of all of the water used in the United States goes to irrigation. Now I don’t mean just the water that you use to water your lawn and garden; much of the irrigation water goes to agricultural production. And that’s important, right? Well, you could grow some of your own food to reduce your dependence on industrial agriculture but that’s not the topic of today’s post.
So how can you collect rainwater for your garden? There are all sorts of ways but let’s start with the simplest: the rain barrel. Rain barrels are an excellent way to capture some of the rainwater that is generated from your roof during a storm or shower. They’re scaleable as you can add bunches of them together so that you can keep collecting rainwater well beyond the typical 55 gallons that each holds. They can be attractive if you’re the artsy type…boy I wish was!
So how much rainwater can a typical roof capture in a single rain storm? What’s your guess? 100 gallons? 1000 gallons? 10,000 gallons? Pull out your calculator (or your cell phone) and let’s do the math. My small rancher has a typical A-frame roof and each side of the roof is approximately 60′ x 20′. That’s 2400 square feet of roof surface area. Let’s say that we receive 1″ of rain. One inch of rain falling on one square foot of roof yields 0.6 gallons of water. So….2400 x 0.6 = 1440 gallons of rainwater. You would need 26 rain barrels just to catch the rain from a single 1″ rain event. In Virginia, we receive around 43″ of rainfall each year. That’s 61,920 gallons of water that you could be catching from your roof each year. That’s a lot of free water for your garden!
So what can you do if you don’t have enough room at your house for 1126 rain barrels (that’s how many you would need to collect all 61,920 gallons)? There are underground cisterns that can be installed to capture your roof runoff.
These are systems that you need do some serious math for as well as figure out how you’re going to get all of that rainwater out of the tank. The beauty of rain barrels is that you use gravity to get the water out of the barrel and into your garden. With cistern based systems, you have to use a pump to get the water to your plants. But the cost of the water that is saved by capturing your roof runoff can more than offset the cost of operating the pump.
What are some other ways to capture free rainwater for your garden if you don’t have access to an underground cistern? How about the tanks that everyone seems to have for sale these days? Check your local Craigslist for great deals. What about 5 gallon buckets to start with? Put one under each downspout to catch rainwater that you can use to water your garden. How about a kiddie pool? You can pick them up for under $10 at your local big box store. Any rainwater that you can catch is water that you don’t have to buy or pull from the depths of the ground to provide your plants with moisture.
What ideas have you used to capture rainwater for your garden? Leave me a comment below or e-mail me at firstname.lastname@example.org. If you enjoy being part of the Mid-Atlantic Gardening community, join our e-mail list (upper right hand corner of this page), become a fan on Facebook and follow me at Twitter. Happy gardening!