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Rainwater Harvesting with a Rain Barrel System

BlueBarrel Rainwater Catchment Systems logoWith water restrictions and drought conditions in many parts of the country, rainwater harvesting is becoming a practical and popular option for homeowners, homesteaders, off-gridders, gardeners, and conservationists. Harvesting your own rainwater is easy with the BlueBarrel Rainwater Catchment System™ from our friends at BlueBarrel.

BlueBarrel is your one-stop shop for the knowledge, materials, and tools you'll need to build a low-cost, reliable, and flexible DIY rain barrel system on your property. They'll source re-purposed, internationally-approved HDPE food-grade plastic barrels in your area for you to pick up, and ship the rest of the materials directly to your door in their DIY RainKit™. Plus, when you use coupon code RGBARREL during your purchase through BlueBarrel, you'll save 10%!

To Order Your BlueBarrel System:
1. Visit to customize and order your rain barrel system
2. Enter promo code RGBARREL at checkout to get 10% off your order!

WHY to Start Rainwater Harvesting

There are so many great reasons to source your outdoor water from somewhere other than your municipality or well.

  • Be More Sustainable:

    Using a rain barrel system on your property relieves overdrawn reservoirs and overworked municipal water delivery systems, allows you to water your garden with natural (untreated) water, protects local watersheds by minimizing runoff that adds contaminants, and reduces your carbon footprint (municipal water treatment requires a lot of energy!)

  • Save Money

    Your water bill is only for water you draw from the municipal water supply. Water you use from a supplemental source (like a rain barrel system) is water the city can't bill you for! Even well water users benefit from rainwater harvesting because water from the rain barrel system doesn't have to be pumped up to the surface by an electric well pump. Some municipalities even offer rebates for rain barrel systems.

  • Prepare for Emergencies

    To be clear, rainwater is not potable without running it through a water purification system. But with a plan for purification (an essential part of any emergency preparedness plan), your rain barrel system is a substantial water storage reserve for drinking, bathing, and more.

HOW to Start Rainwater Harvesting

Plan and order your rain barrel system in 4 easy steps. For more information about any step in the process, head over to BlueBarrel's Do-It-Yourself page.

  1. Understand the Space Requirements
    Each rain barrel requires a 2' x 2' footprint and 3'8" of height when using the recommended cinder block foundation.
  2. Size Your BlueBarrel System
    a. Calculate your potential rainwater catchment volume in gallons (square footage of the roof segment your rain barrel system will be under x inches of average annual rainfall x 0.6). A 500 square foot roof segment receiving 11 inches of rain per year will generate 3,300 gallons.
    b. Calculate how much water you will need in gallons - remember that rainwater is NOT potable unless treated, so your use of it will most likely be limited to irrigation. You can estimate irrigation water volume needs by looking at old water bills or with the generic formula of (square footage of your garden bed x number of weeks in your dry season x 0.5). A 200 square foot garden in a climate with a 5-week dry season will need 500 gallons per year.
    c. Decide how much space you want to devote to your rain barrel system. Each rain barrel holds 55 gallons. If the numbers you got in parts A and B seem like way too much water, just go with a system that fits where you want it to fit!
  3. Site Your BlueBarrel System
    The best place for your rain barrel system is on level ground near a downspout on a side of the house that gets shade, and near or uphill from your irrigation area.
  4. Click the button to order your rain barrel system

BlueBarrel Rainwater System FAQ

Answers to common questions about rainwater harvesting and the BlueBarrel System.

Can I catch enough water off my roof to warrant a rain barrel system?
You'll be surprised how much water you can catch off your roof, even in a dry climate. You'll get more than 0.6 gallons per square foot of rooftop per inch of rain. With a 1,000 square foot roof, an inch of rain translates to 600 gallons of free irrigation water!

Can I drink the water from the barrels?
Not unless it is properly treated first.

What did the barrels have in them?
The barrels are re-purposed (once-used) food-grade barrels from BlueBarrel's nationwide network of partner barrel suppliers. You will find out what was in your barrels before you select your re-purposed barrel supplier during your purchase. Remember - harvested rainwater is not potable without treatment. It is primarily your plants you're thinking about here, and they should appreciate trace organic matter in their water.

How big are the barrels?
Each barrel is about 36" tall, 23" in diameter, and holds 55 gallons. You should plan 2' x 2' footprint for each barrel with 3'8" of height. Barrels weigh about 20 lbs empty and almost 500 lbs full! For more details, see the BlueBarrel System's dimensions.

What if there’s no barrel pickup site in my region?
BlueBarrel adds new barrel supply partners every week. If they don't have a barrel supplier in your region, you can fill out their barrel supplier request form and they will help find compatible barrels near you!

What if I already have my own barrels?
Then you're one step ahead! BlueBarrel's interactive online store will ask you a few basic questions about your barrels to make sure they're compatible with their DIY RainKit™.