Rain Barrels





Introduction: Rain Barrels

After picking up 5 cheap 55 gallon barrels it was time to put my new gutters to use.

My goal was to create a modular barrel system that was first and foremost, CHEAP. I was inspired by a couple of other great rainwater reclamation systems here and felt I could put a different spin on the process.

This project came in at 220 gallons of water storage for less than 30 bucks a barrel. Everything was purchased via 'the bay' or 'home despot' except the barrels which I found on 'cragg's last'.

at the end I'll review some changes I'd make if I had it to do over again- but they're working great here in the wet N. Texas.

Step 1: Ingredients:

Following this instructable will create TWO 110 gallon rain water reclamation units. This system is modular so it could be easily adapted to single barrel or multi barrel situations.

My list of materials:

4 55 gallon blue barrels (for the love of god make sure they're food grade, otherwise prepare to water your lovely garden with acetone, gasoline, or any of a dozen other lovely chemicals).

4 2 inch through-hull connectors- I'll discuss these lovely widgets later on.

2 threaded 2in PVC connectors (overflow)

18in of 2in ID (inside diameter) flexible hose (this stuff is big $$!)

2 standard threaded brass hose bibbs (connector thingies for garden hose- mine were 1/2in on the hose side and 3/4in on the 'connect to barrel' side).

2 4in drain hole covers

Silicone caulk


Dremel plastic/wood cutting bit for smoothing or widening holes in the barrel

Step 2: Prepping the Bung Hole

First things first- how is the water from your downspout going to get INTO the barrel?

I needed an easy way to keep leaves and other 'unmentionables' from getting into my rain barrel through the bung (yes- I'll be using that word liberally as it's the official term for 'barrel hole').

Using my trusty drill I drilled out one of the threaded bung holes to fit my drainage grate. This green widget keeps leaves out and water in. There are a lot of ways to keep leaves out, this just seemed to work and is CHEAP. As of now I do have to manually clean leaves out of the downspout, but none clog up my bung hole!

Step 3: Tying Two Together

since I really couldn't stack these vertically given my wife's aesthetic needs (I'm not having a great ugly mashup of plastic towering around my house!) I chose a more subdued configuration. This necessitated holing the barrels and connecting them.

After hunting for bits and pieces I came across the perfect fitting- a through-hull. These are used on boats to pass fluid (grey water and cooling for engines I presume) through the hull without sinking the boat.

I drilled a 2 inch hole and put one of these fittings about 6-8 inches from the bottom of each barrel. Since these fittings are typically barbed, it made for a great fit with the plastic tubing. Just make sure the through-hull fitting and the tubing are the same diameter.

The easiest thing I found was to fish the through-hull through the reamed bung hole (yes- I reamed 4 bung holes to complete this project) using a coat hanger. I placed a nice bead of marine grade silicone on the flange and tightened the nut from the outside of the barrel. This cinched down nicely and made a watertight fitting.

I tried this with an 18in length of tubing and found that 1/2 that length is better.

Step 4: Fluid Release Systems

Water now flows through the grate and into the open bunghole, across the vinyl tubing from barrel one to barrel two. Water must be released from barrel two otherwise it's more of a 'mosquito breeding and algae farm' versus a water reclamation and reuse system.

The obvious way to release pent up water is to have a hose and hose bibb at the bottom of the second barrel. REMEMBER KIDS: water flows downhill, therefore, make sure barrel two is DOWNHILL of barrel one. this allows them to both fill and for water to come out of the hose when you want to water something.

These barrels are quite thick. I placed the bibb at the bottom of barrel 2 about 4in off the ground. Low enough to get most of the water out, high enough to keep the hose from kinking. I drilled a 1/2in hole in the side of the barrel and slowly dremeled the hole wider until the brass fitting cut its own threading into the plastic, leaving me with a strong, watertight seal. It's key not to ream this hole too large or you'll have a leaky bibb.

Do the same thing up top for your OVERFLOW. Overflow is important. 1in of rain on a 1000sqft roof will give you about 623 gallons of runoff. since my gutters cover 1/2 of my roof footage (about 1200 sqft) I anticipate these barrels being full at some point. When that happens I want to make sure the excess water heads out to the street to the public drainage system. Drill a 1 3/4 in hole in the top side of the barrel and ream until the PVC fitting will cut a thread in the sidewall to create an overflow.

Step 5: Final Thoughts

I'll be hiding these with some cheap lattice and connecting some soaker hoses to these for watering my garden. We've had a couple of small rains and they're working to specification.

If I were to do this again I would countersink the grate on the bung hole or possibly a leaf trap on the down spout. I would also place the connector tube lower down the barrels, as it stands I may just add a hose bibb to barrel one if I find I'm having standing water most of the time.



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    36 Discussions

    You'll find lots of parts to make your rain barrel project here:

    and here too:


    DARN! You're soooo lucky! I've been checking Craigslist everyday for the past six months and the lowest the drums/barrels have gotten was $20 each.

    Would you tell me where or how these can be obtained? I live in the Rio Grande Valley in South Texas.  treelady

    For mosquito control I heard that putting a few cheap goldfish into the barrel will solve that problem. The fish will eat the eggs and larva of the bugs. I don't know how well this will work. I just heard it works.

    2 replies

    i always thought mosquitoes bread in small, still, shallow pools of water so if you have an ample amount of water, mosquitoes shouldn't be a problem.
    But i have heard that about the goldfish as a general water pest "killer"

    I have heard that too. You can also put 1-2 drops of oil on top, which keeps the mosquitoes from breeding.

    Mosquitoes Out!
    I don't know if anyone mentioned this already. Build a sand filter with a vertical section of gutter pipe that it easy to disassemble for cleaning. The vertical placement facilitates the draining of water from the sand to avoid that the moisture attract to the mosquito. I think that an ideal filter would be of varying thickness of sand (three, for example).
    Place the filter in the bottom of the downspout of the gutter, at the entrance to the reservoirs. This will prevent both the entry of solids such as mosquitoes to deposit.

    What do you tink about this idea...?
    Greetings from Spain

    Thanks! We are getting ready to put our garden in and this is exactly what I was thinking of doing...now I have a good idea of what I need to do. Again Thank you for the excellent Instructable. BTW this is the first time I have ever posted a comment.

    Have you considered putting a drain bibb at the bottom of the 1st tank so that you can drain the inevitable "roof sludge" that you will slowly build up on the bottom of the tank? Also either lowering the bibb on the 2nd tank, or perhaps using a 2nd bibb on that tank for the same reason may be good. In order to keep bugs out of the tanks, you may want to run the pipe from the gutter straight into the tank and then use a separate, external, "filter box". I've thought about doing this very same thing .. great idea!

    1 reply

    Had a couple thoughts on this. 1. design the system such that barrel one is a French well. outlet being placed somewhere 2/3 up the sidewall. This should allow the water to settle out the particulate and not advance to the actual reservoirs. 2. if that first barrel were designed like a trombone, then you could adjust the water level for discharge based upon season rain event expectations. such that a lighter rain will get into the reservoirs. 3. as the barrel is likely to be near the foundation. design the french drain floor to be within a larger barrel. then plumb an outlet to tile system away from your buildings to drain the french drain and reduce mosquitos concerns. 4. as the first barrel is now slidable. Make it so that it can be removed. Now have access to clean out the floor of the french drain annually. 5. don't fixate on passive drainage of barrels only. They do make solar powered water pumps. Using these you can pump the water from the barrels to where ever you need it. Such as a soaker hose irrigation system, etc. 6. By pumping it, you can then submerge the tanks into the ground. Just be certain to call your states "Call before digging" hot line so as not to break a utility line. Save some dollars and possibly a life.

    I stopped a scrap dealer in his pick-up and trailer and he delivered two white Plastic 30 gallon, and two 55 gallon blue plastic barrels for $20 total, with a promise to bring four more blue 55 gallon plastic barrels for $20. Plastic gutters for my two 50 foot rooflines ran a total of about $150 for everything, I also arranged for putting aluminum flashing (50 foot roll, $18, at Lowes) on the edge of my neighbor's roof (under shingles, above existing edge flashing), to drain over into my gutter between our homes where the foundations are only 4 feet apart, and the roof edges are 10 Inches apart! These 1555 sq. foot homes have peaked roofs that flow thousands of gallons in a normal year in Florida! Overflow, if any, will go down hoses from the barrels, and into the nature preserve behind the property. This will remove a serious foundation wetness issue for both of our homes. For the proper 'HEAD' pressure to feed soaker hoses, every 27 inches of elevation of the faucet gives 1 psi. So, I will build a barrel rack of Landscape timbers, about 3 feet of the ground, and place the faucet another two feet up on the feed barrels.

    For a really aesthetically pleasing barrel, I recommend trying to find a distillary or vinyard nearby. I live in KY, and since bourbon barrels can only be used once (by law), my rainbarrels are all constructed using these - purchased for $10 ea. after being used by a microbrewery, so twice recycled!

    I found my barrel at a feed and seed place for 12 bucks. i had to add the spigot myself. also you could check a winery.

    i built one of these a while back, and found that the main issue was the whole gravity fed limitation... so ingenuity prevailed! when i first built the system, i kept the original bung intact as the only inlet, and tapped a tight fitting outlet near the bottom. the easiest way other than using a pump was to pressurize the barrel with air. i put a simple 1/4" air compressor valve in the top, and now whenever i need pressurized water, i just run a line from my 80 gal air compressor and turn the water valve open. it works kind of like a giant super soaker! be careful not to over pressurize it though, I'd recommend getting a regulator and setting it for only 20-30 psi.

    great! Oh you could water plants-grass w that, or mabe.. just mabe, hook something up to use that in a toilet :-P? huh? huh!?

    1 reply