Introduction: Build a 3 Drum Rain Collection System Better

Picture of Build a 3 Drum Rain Collection System Better

I live down in south Louisiana & plant a vegetable garden every year.  Now even though my area is considered tropical, we do have dry periods. Watering my garden  from the tap hinders the growth because of the
chemical and algae inhibiters that they add to make it drinkable (potable). (not to mention what the "crooks" at the water dept. want to charge you!!) Any nursary or avid gardener will tell you that tap water is not the best thing for your garden.  When it would rain my garden shoots up 4 inches overnight!! (dramatization) So I began searching for a way to capture and store all the free water i wanted. After looking at project after project I found that IpodGuy's stacked system was the best one for me...(with some improvements of course!!)


I looked at plenty of designs that used the vertical placement method. you'd better set aside a lot of landscape to set up that way.  but with all of them you have to drill vent holes or cut large fill holes & I didn't want to destroy my drums like that. With the stacked system there is no pumping needed. Everything is gravity fed. (and pretty good pressure to boot)

SO HERE WE GO..........

First of all let me clarify for the grammer nuts: these drums are layed horizontally, & stacked vertically.

Here are some of the changes I made from Ipodguy's design:

1) simpler design and easier to build.(approx. a 12 pk. job) A horizontal "stacked" system takes up much less space than placing them side by side vertically. Great if you don't have much room to spare. (go up rather than out!)

2) I removed the tilt of the barrels. Unless you cut/drill vent holes in each of the barrels, they will only fill to about 75%. I want to utilize the maximum amount of storage from these three drums. Being level, they should fill to about 95%, plus if I decide to dismantle the system and use the barrels for something else, I have that option since I haven't rendered them useless by cutting or drilling holes in them.

3) I changed the installation to a much less permanent one. Instead of digging holes and cementing it in, I will mount the system on concrete blocks (think i pd. $2.59 each for them).
in case i need to move the system or use the drums for another purpose.

4) I implemented the "cradle" design which makes the drums part of the supporting structure. This way I do not have to use 4x4's to bear the weight of three full drums. The 2x4 legs are basically there to hold the whole thing together and for bracing.

5) rather than use expensive (and hard to cut) 4x4's....I used 2x4's. It is still as strong as a 4x4. Its just the reinforcement that matters.

6) kept metal out of the system completely. (which doesn't matter if used for rainwater anyways)(comes in handy if i need to convert this to my SHTF fresh water supply. (yep...i'm somewhat of a doomsday prepper)

With the horizontal mount you don't have to worry about cutting uneeded extra holes in your barrels therefore destroying them. The top drum vents the entire system via the hose connections (see video) as well as making the whole thing essentially one tank.

Once again, this doesn't involve any cutting of the barrels that basically render it useless if you decide to dismantle it & use them for something else down the road.


First of all I cut my cradles that will be used to support the barrels. i simply traced the outline of the drum and cut from there. I cut ten of these. With this design i should (and that a very strong word) should be able to stack three for my system.


I used 2x4's for the legs. Now you might think this may be a bit flimsy for supporting 3 filled 55 gallon drums (approx 500lbs each.) but the cradle pieces between the drums are part of the support themselves. The 2 x 4's are basically there to hold the system together. (of course....I'll test it to just to make sure)

step 3
Assembling the system and installing the drums. the plywood on the sides is for bracing, eliminating any sway from front to back. The cradles will brace any side to side sway.
I will also test the system to ensure that the cradle system & 2x4's will handle the weight.


Pretty much adding the plumbing to the drums. My drums had threaded bungs on both sides which made this design possible.
I found these nifty little gray 3/4" NPT angle fittings that connect the drums at Highs (lowes). They do the trick nicely and only cost about $0.89 each. (much cheaper than brass hose fittings)


Testing the system. I filled the water on the top drum and it vented nicely down to the next two drums. the video shows one of the connector tubes as the water traveled down and the venting process occured at the same time. performed rather well, i think!


Finished system. The drums as well as the 2x4's supported the weight nicely. I can now drain it & disassemble it so i can treat the 2x4's as well as paint it.
I will add the inlet from the gutters later, but it will simply pipe my gutter to the upper hole on the top drum...(see...still no cutting of the drums!!)


almost complete with the rebuild. purchased treated wood and treated it once more myself. added the t-fittings
Rebuild complete...and just in time for the rain!! Here is a video of the system filling from the rainwater.



UPDATE ON THE UPDATES....  After about a half inch of rain yesterday and collecting only about 20% from the gutters my system has filled to capacity! I may keep the crude collection system because you do not want the rainwater entering the system at a rate thats too fast for it to settle to the bottom drum (gets top heavy) I guess it all depends on how much rain you actually get. if you only get a half inch or so every month, you may want to collect every drop you can, but I'm in a rather tropical area, so its not as critical for me here.
thanks for all the comments and suggestions. most of them i will implement into the system to better it. Its no secret.....this is a dual purpose unit. I am a doomsday prepper and this will be used as my freshwater source if the SHTF. But until then it will make an excellent vegetable garden water provider. Also a suggestion was made about piping the top holes together and the bottom holes together for easier fill during heavy rains. This is an excellent idea. Another person commented on the amount of sediment, dirt, bird fecal matter and general BS&W that washes off of the roof. Not a problem if your just watering your garden, Big problem if you are reclaiming for drinking.....YUCCHHH!!!  Soooo.....i added a small riser to the inside of my gutters outlet. this prevents any heavies from entering the system. a good suggestion is to let it rain a few minutes before you connect your collector. LET THE CRAP RINSE OFF OF THE ROOF


jbarrett4 made it! (author)2017-08-07

I've been scanning the instuctwbles website for years. Most interested in rain barrels and solar stuff. But this is the first project I've ever actually done. I love the verticals space saving part of it. It fits perfectly at one end of my garage.

I still need to shorten the tube coming from the down spout a little, But want to see how this length works first. Also, I'm planning on using the catch-a-raindrop attachment in reverse for my over flow. I had originally hooked it up the right way but it didn't catch as much of the water as I wanted it to.

merleman (author)2015-02-22

very interested in this but does anyone know a quick and safe way to make this ok for my family to drink? trying to find ways to simplify my life while still providing for my children without making them ill.

FrankL108 (author)merleman2016-12-11

You can try talking to a home water filtration place that sells R/O Systems and adding a Ultraviolet Light to kill the pathogens. Keep it simple and down to one tap for drinking or cooking and it should work great for you,

chaddican (author)2016-06-02

lperkins is right about checking for your local regulations; it is illegal in Colorado to catch the rain water, even if you don't have a well or aren't attached to "city water". They have a lot of other "rules" about water, it is VERY regulated in this state.

LokiWartooth (author)2015-08-17

Cajundood where abouts in the south are you? Im a prepper too and I'm about two hours from Baton Rouge close to Tx border.

LokiWartooth (author)2015-08-17

What's insane is they don't want use to catch and use our own water, and they pollute every chance they get with pesticides, chat from mines, and even the water company puts monocloranine and fluoride in your water and tell you it's ok. Well if fluoride is ok then why does it say on toothpaste that even if you swollen a pea sized amount to call poison control and they tell you it's good for teeth which it's not! Something stinks about that!!

LokiWartooth (author)2015-08-17

Thank God here in Louisiana we can still catch and keep water. Some states have gone nazi and won't let you. And if you use a berkey black element it's purifies and filters the water

lperkins (author)2012-05-18

Nifty design! :)

Be sure to check local regulations and whether or not you own the water rights to your property. (Yes, stupid as it sounds in some places it's illegal to catch rain water.)

RowanOathKeeper (author)lperkins2014-12-23

A great reason to place this around back!!!

LarryLKendrick (author)2014-10-19

If you paint the barrels black, it will make the water real hot if there out in the sun

LarryLKendrick (author)2014-10-19

instead of useing the clear tubing, I was thinking of using black to prevent alge growth and to gain the sight glass use a sight glass with a filter off an old diesel tractor. The filter could be changed once a year to keep the water clean kinda like you would keep the fuel clean on the tractor. any Ideas ?

Jshdoit (author)2014-09-03

Due to runoff, bacteria & animals - I recommend setting up a little Different with 2 (55) Gallons on top of Each Other & Advanced Filters - 4 Pair of them Which will Purify & Filter all Water -Remove all Contaminants,Bacteria,Viruses, Cyst & More!! Can be Used For Rain Catchment and or Disaster Relief of Both!! For more info about this. Message me for more Info!! Can Email info Private!!

jcook45 (author)2014-02-15

I got an empty barrel from my workplace which was previously full of windshield washer fluid. I rinsed it out, stood it up and then cut the lid out so I can dip a watering can in for the rain water which works great for watering my mini garden, super simple, ez set up. Only problem is the algae that grows and grows as the summer goes along. Should I do something about the algae, if so what, or just not worry about it at all.

nofin (author)2013-08-22

Wow Cajun! Thanks for your hard work! A few ideas here:

1- Angle the end of the rain gutter track down slightly and integrate a screen that feeds into a 6"+ diameter vertical pipe that runs the height of the house. Provide so that overflow can still travel past the screen and down the regular rain gutter. Thread the bottom of the 6" pipe with a large cap for easy system evacuation. This is your overflow that doubles as a catch for the first several gallons of pollutants per storm. Tap into the vertical pipe near the top with your 1" main feed.

2- Link the bottom vents of each barrel together (in the same manner shown) and connect them to your main feed. Link the top vents of each barrel together using a separate hose system that vents to a point higher than your main feed hose. Screen this vent against insects. Rotating each barrel 1 degree will make for 2 separate straight feeds and still allow 94% drainage from each barrel.

This eliminates bubbles in the system, sludge from storms, excessive fill rates, and will fill the bottom barrel first. evacuate the overflow pipe and check the gutter screen after each storm.

afon.guard (author)2012-11-05

Fantastic design!

I have finally gotten around to building this system with a few modifications (and much more grude craftmanship...). I'll be posting my own step-by-step as well.

I'm wondering what you ended up doing for the diverter? From the looks of it, your top barrels' inlet is about the same height as your roof, which doesn't seem to work well with most of the diverters on the market.

I bought this one, but my downspout angles toward the house 2 inches down and where it connects to the long feed to the ground is well below the top of the barrels... ideas?

shesell (author)2012-08-14

Evidently, it's now OK to use the water God sends your way in Colorado. Here's the link to an article in the NY Times:
Great instructable! Very clear and concise.o

jspence1 (author)2012-05-16

Could you put an "L" connector on the top bung of the top barrel with a short piece of pipe on the upper side of the "L" as an overflow? Short piece of pipe
would extend above the top of the barrel so the top barrel would fill all the way.

I'd be interested to know what the water pressure is at the spigot. Do you have a water pressure gauge by any chance?

cajundood (author)jspence12012-05-21

i'd like to know the water pressure myself. if i ever get a hold to a guage i'll hook it up and update eveyone on what kind of pressure i got.

paqrat (author)2012-05-15

I have been looking at your tubing and am wondering, does this fill from the bottom barrel up? It looks like water would just flow down the tube and not go into a barrel until it ran into a blockage and had to go into the barrel.

cajundood (author)paqrat2012-05-16

actually it fills from the top barrel down. the tubing acts as a fill tube, venting tube, and sight glass ....all in one!

paqrat (author)cajundood2012-05-16

I think what confused me is there appears to be two pics of barrels with tubing. One of them seems to show a single tube that goes down all three barrels and is attached to each barrel with a "T". The other pic shows tubes going in barrels with other tubes coming out of the barrel. The second pic I described is a layout that looks logical. The first pic is the one that doesn't look like it would work unless it worked by filling the bottom barrel first then back up to fill the second barrel then backing up to fill the first.

I feel I should apologise for not having said what a great idea this is and that it seems to be executed well. When I get the roof fixed I plan to add gutters and downspouts and I believe something like this could prove very useful. I live in north Louisiana and don't water so most of the grass has died. Something like this could possibly save the remaining lawn.

cajundood (author)paqrat2012-05-17

its actually complicated....(the way it fills) the gutter spigots into the top barrel, then once you get approx 2" it begins to drain out of the bottom bung, down the tube to the lowest point before entering a barrel. aargh....i'm confused but thanks though for the compliment. its an ongoing process and i am constantly making changes from the suggestions that i am recieving.

GNiessen (author)2012-05-14

If you plumb the top vents together in one string and the bottom openings in a second and feed the in coming rain water to the second you will get better flow as the air will vent out without having the swim up stream. This will work better during heavier rain fall.

cajundood (author)GNiessen2012-05-16

excellent observation. actually i never thought about that. it would certainly vent easier and quicker, then would simply fill up as the level rose. might have to try that.

tn. (author)2012-05-13

grammar nazi: "horizontal" means side-by-side, top-to-bottom is "vertical".

just sayin'.

16777216 (author)tn.2012-05-13

I believe he was talking about the position of the individual barrels and not that of the stacking.

cajundood (author)167772162012-05-14

STACKED VERTICALLY..........better??????

mfslater (author)cajundood2012-05-15

Hi Cajundood

Your grammer, correction, grammar, is mostly there except that it's "laid" and not "layed".

Swiss grammatician

tn. (author)cajundood2012-05-14

yep - i thought i was missing a vital step as it's something we're going to be doing here.

tn. (author)167772162012-05-14

that would make sense, then, lol. mea culpa.

Norsefalconer (author)tn.2012-05-13

I don't know for sure but, I think "cajundood" is referring to the orientation of the barrels themselves, stacked horizontally vs stacking vertically.

Geedox (author)2012-05-15

Great Idea! Kudos! I live very far from any water mains, and a well on property is out of range due to Geology and limited. funding. I catch All the rainfall from the roof and store it in a 30 cu/meter (30.000 liter) concrete covered tank. We have installed debris screens on all downspouts using using inverted Sanitary 4 or 6 inch "Y" fittings. We keep the roof clean by sweeping it just before the rainy season, and by keeping all overhanging branches trimmed to within 2 ft (60 cm) of the eave line. We treat the water with unscented household chlorine bleach. It takes about 1.5lt per month. All water for human consumption (drinking/cooking) is further boiled for 5 to 8 min. As policy, the tank is cleaned once a year to keep it free of algae and other debris that slips thru. I will try to post some photos. Keep it up

jamminstruc (author)2012-05-15

Well done, thanks for this excellent instructable

bsims1 (author)2012-05-14

It looks like Ts really make a difference in venting. Good job cajundood!

You could use an angled screen to cover a diverter in the downspout. The water pours out of the gutter straight down into the funnel that leads into a hose to the barrel. The screen sits on top of the funnel at a 45degree angle. Any debris that hits the screen, washes to the side and down the rest of the gutter pipe.

In ponds and fish tanks, peat and barley straw is used to control algae. If you had the drums with the removable lids and banding, you could open up the bottom barrel, clean it out, and put a fresh bag of peat and barley straw inside 2-3 times a year.

thebeatonpath (author)2012-05-13

Great job! I need to hurry up and make a few of these. Disgusted at myself while I watch all of this rain fall today with no barrels set up!

cajundood (author)thebeatonpath2012-05-14

ya.....just watching all that free rainwater going down the drain and soaking into the ground is disheartening. course, if you lived in CO it would be illegal to collect that rainwater!!! If thats a true law up there....those ppl have their head screwed on backwards.

thebeatonpath (author)cajundood2012-05-14

Yes, I'll be kicking myself come July & August. We're in TN and it's either feast or famine with rain. Illegal to collect rainwater?! Does that mean the CO folks don't own the air they breathe? I heard the air is thin there, but this is ridiculous!

velcro2 (author)2012-05-14

Great instructable. I'm using a similar rain barrel collection system with the run off from the roof. HOWEVER, I have to flush my rain barrels every 3 or 4 months because of the sludge and foreign material that gets deposited at the bottom. It also contains large amounts of bird fecal matter, algae, pollen dust, fir tree needles and sap, etc. I use the 40 gal. plastic trash cans with a drip irrigation system. Your conservation idea is great but would there be an easy way to flush and purge the barrels over a period of time?
Here in Washington state we also have a law banning the collection of rain water on your property. It makes as much sense as the law banning red cars in Cincinnati from the 1920's because emergency vehicles were red. Or was that Cleveland? Well, you get the idea.
I think a large plastic hoop wrapped with cheesecloth might make a good pre-filter between the gutter downspout and rain barrels for those using a drip irrigation set up with their rain barrels. Thanks for your instructable.

cajundood (author)velcro22012-05-14

omg....another area that has laws against capturing free rainwater from the sky. your local water dept. must have some serious pull....because they want to sell you the water. its like telling someone you can't breathe the air thats all around you, but we'll sell it to you for a cost!! (hmmm...i remember a movie about that)
my system has not been in service long enough to start collecting sediment, but i'm sure it would be a problem eventually. some sort of prefilter on the gutter outlet would probably filter out most of the things that would clog up your system.
bleach or some sort of pool "shock" would hinder any algae growth reducing further any gunk buildup on the bottoms of the drums.

mbelanger3 (author)2012-05-14

Hey Cajundood,

Nice design; I like the vertical space-saving idea and the method of filling top-down, rather than trying to balance horizontally.

Question for you:

- What type of tubing is connecting each barrel? How big is it? Looks like 3/4 inch PVC or some sort of vinyl/plastic hybrid.

- Speaking of the plumbing bits, I'm wondering how you matched the barrel opening to a well-fitting seal (and of course, the nifty little spigot bit. Looks like a 90 degree elbow of some size or another).

Bit of a plumbing newbie, so if you happen to have a parts list or links to Lowe's/HomeDepot etc, that would be super!

Best wishes with that setup; may your barrels be always filled!

cajundood (author)mbelanger32012-05-14

the tubing is your standard clear tubing 1" ID that i found at my local hardware store. buy it off the roll. its black now because i added electrical tape to most of it to hinder any algae growth and still have a sight glass to check my level.
The PVC t-fittings came from High's (lowes). Its in the pvc fittings section....lawn irrigation/watering fittings to be more precise. They are a dark grey color and work very well.
It wasn't very hard to put the fittings in. most of your 55gal drum caps(bungs) have 3/4" threads built into the cap. you just simply cut out the inserts.

mbelanger3 (author)2012-05-14

Hey Cajundood,

Nice design; I like the vertical space-saving idea and the method of filling top-down, rather than trying to balance horizontally.

Question for you:

- What type of tubing is connecting each barrel? How big is it? Looks like 3/4 inch PVC or some sort of vinyl/plastic hybrid.

- Speaking of the plumbing bits, I'm wondering how you matched the barrel opening to a well-fitting seal (and of course, the nifty little spigot bit. Looks like a 90 degree elbow of some size or another).

Bit of a plumbing newbie, so if you happen to have a parts list or links to Lowe's/HomeDepot etc, that would be super!

Best wishes with that setup; may your barrels be always filled!

jeffopus (author)2012-05-13

Menards and other stores sell black hose in the same sizes as clear to prevent the growth of algae, you can also paint the barrels themselves black with a PVC paint to prevent algae. Home improvement centers also sell square and rectangle to round connections that are for gutter to PVC tubing for taking your gutters to a storm drain system that work great for barrels, simply use a 4" or appropriate hole saw into the top barrel.

I have three sets of rain barrels and use gardening tubing from Drip Depot to distribute water to my garden. Here s the review on my gardening system:

Jeff Gedgaud

cajundood (author)jeffopus2012-05-14

i did check on the black irrigation/ sprinkler system tubing that you are referring to.......its not as flexible as the clear and you need to manipulate the tubing in order to get it onto the t-fittings. plus with the black tubing you lose the sight-glass ability.

jeffopus (author)cajundood2012-05-14

Menards sells two different types of tubing, one is a black died just like the clear stuff while the other is the sprinkler stuff your talking about but I understand what your saying. To get the tubing workable try using a blow dryer to soften it up, it worked great for me when building my rain barrel systems. I don't bother with a sight gauge but I would recommend a valve at the bottom to help as a cleanout, I put T's at the lowest point of the system and have the one end facing down going to a valve that just drains out any debris.

Jeff Gedgaud

Tinker_001 (author)2012-05-13

I am kinda curious how you cut that half circle with a circular saw. (third Picture)

cajundood (author)Tinker_0012012-05-14

I'm just good like that!! .............................LOL nah just kidding. The skillsaw just happend to be in the picture. I used a jigsaw to make those cuts. it does takes awhile on treated 2x6's but eventually I got them all cut.

nanhi (author)2012-05-13

A great idea specially in water starved places. Rain water harvesting in Bangalore India is required by law. Here is a cheaper vertical stacking method using plastic or wood Drum Pallets. For stability and space saving each pallet take 2 or 3-drums. You place the first pallet on the ground. Then put the drums on it. You place a drum pallet over the drums and so on. The limiting factor is the stacked weight carrying capacity of the drums, as the bottom most drums have to bear all the load.
The Drum Pallets are self stabilizing so nothing else is required - it is that simple. You don't even need the concrete blocks, especially if you are using Plastic Pallets. Vertical Drum Racks are also available. Here is a link to drum pallets:-
Bipin - from a far away enchanting land.

cajundood (author)nanhi2012-05-14

those are awesome!! i didnt even know they existed. but since i'm poor, i can't afford to have something nice like that, so i must fabricate something myself.

doublequick (author)2012-05-13

Have you tested this in an actual rainstorm yet? I'm thinking your tubing is way too small to keep up with the flow of water coming off the roof.

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