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Picture of Rain Barrel for Garden Watering

I have entered this into the garden contest! Please like!


The purpose of this project is to collect rainwater into barrels to be used at a later time to water the garden/grass.


I spent a lot of time looking at different designs, how people built them from very easy setups (1 barrel) to multiple barrels (6+). The most important thing to note is that if you are going to use this for a garden, ensure that you get barrels that are food grade safe. Sometimes these barrels are used for chemicals which can kill your garden, or be absorbed and ingested (if you are growing food - like I am)


After obtaining your rain barrel(s) make sure that you take some time to clean it. Mine used to hold soy sauce (it stinks!)

Step 1: Required Parts

Picture of Required Parts

Here are the parts that I used:

2 x 55 gallon food grade safe barrels

2 x 2" DWV MIP Adapter

2 x 2" DWV Street Elbow 90 degree Spigot x Hub

1 x 2" PVC Pipe 8 feet

2 x 2" PVC Tee (t section = 1 1/2" opening)

2 x 1-1/2" x 3/4" PVC Schedule 40 Bushing Spigot x FIPT

2 x 3/4" Short Galvanized Nipple

2 x 3/4" PVC Ball Valve

2 x 3/4" MPT x 3/4" MHT adapter with red valve

1 x Plumber putty

1 x 8 feet downspout extension

1 x downspout adapter with twist on (Connects downspout to extension)

Lots of extra garden bricks

Tools Used:


Utility knife

Drill bits


measuring tape

GTO3x24 months ago
You probably already know, but the overflow might give you problems: too small, not piped to drain (extremely bad for house). You might have to go the full gutter size, and back to the downspout storm connection. The water can even back-up in the supply line.

Wonder if you could get by with: put downspout the way it was. Then put a 1" threaded fitting in the side (use gaskets and 1" electrical nut). Then, a scoop needs to be made; get another threaded fitting and cut/form it to make a scoop. This may not work because of the tendency of water flowing at downspout wall, but I'd guess there is enough splashing to have water fall through the center for the scoop to pick up. As is, those barrels might fill/top-off in a matter of minutes.

Just some thoughts.
CalebL40 (author)  GTO3x24 months ago
Yeah I'm going to re think this. We just had 3 straight days of rain and this filled up in no time. As stated I'm redoing my deck so how it flows away from the house will he slightly different
GTO3x2 CalebL404 months ago
I have a downspout diverter valve. I think I got it on e-Bay. It works well, but it is manual.

I recently added an L-bracket with a pull-string (and eyelets) to ease the switchover. I can then give it time for first-flush and then switch over to fill the container. Automation can go anywhere from here, but it would be quite involved. You may want to arrange yours to pull it closed.

Anyway, good luck.
CalebL40 (author)  GTO3x24 months ago
That is really smart! I may look into doing something like that using automation. I think it would be easy to automate using a float valve (like a toliet) and once it reaches a certain level, switch the overflow to go back down the downspout. May look into that one. Great idea!
CalebL40 (author)  GTO3x24 months ago
Appreciate the feedback :)

We have had a lot of rain over the last couple weeks, and the overflow is working perfectly! There was only 1 night where it was really bad and I had water coming out of the air holes. I will likely be cutting a bigger hole for overflow to help.

The overflow that is there will be connected with a hose that will lead away from the house (Where the water currently overflows is far enough away from the house - and there is a slant away from the house) that this will not be an issue. Nevertheless, I want to overflow to run further away (eventually overflow will lead to another garden/tree).

When I redo my deck, I will be changing how the barrels connect with the downspout. I will likely be creating a overflow that will feed back into the downspout.
ScottB2314 months ago
I feel your design is very revolutionary. If you had inspiration from others, please share! In my area it rains for only a short time each year, so storage can be an issue (like, where do I put a tank that is 10' dia. and 8-10' high?). Mounting the barrels physically in series, but hydraulically in parallel would fix that for many, i.m.o.

I really like the inverted barrel with the dual valves. It eliminates bulkhead fittings and the cross-piping easily shares storage capacity across several barrels and doubles as a bottom drain for seasonal cleaning. The vent holes in your design are needed (and the small size acts as a bug/debris filter), but my preference would be for a single point of overflow on the first barrel and directed somewhere easy to manage in that event (like the pressure/water blow-off on a traditional water heater).

How often does it rain in your locale? You have pre-screening at the rain gutters, but you may benefit from a diverter between the downspout and the barrel so the dust and stuff that collects on the roof between rains that washes off in the first few minutes of rain doesn't go into the barrels (less maintenance and water quality issues over time).

Also, I would like to echo dleland71's caution about the foundation. For each barrel I would plan for a 200% dead load, which (if my math is good) will be in the neighborhood of 280 - 300 lbs./sq.ft. Some references on DIY aquariums may be a good source for additional information.

Again, good job!
CalebL40 (author)  ScottB2314 months ago
Thanks! Like I said I looked at tons of different design from a lot of different people! I thank the whole rain barrel community lol

I do have an overflow that is hidden from in the pictures. It is in the second barrel. After installing this, we had 3 days of pure rain and it filled up very quickly and the overflow worked like a charm.

I hear what you are saying with the filter/diverter. Any dust or fine debris will make it to the barrels. At this point, it should be very small and come out with the water. I am only using this to provide water to my garden and lawn (not drinking) so it is okay for a little bit to make it in. I am more concerned with the big stuff (leaves etc) as they can plug up the system.

I live in Ontario, Canada. We do get a good amount of rain, but I wouldn't say it rains all the time or anything like that. We do get some dry times here and there

As it turns out I am also in the aquarium/paludarium hobby and very familir with this weight. As I said early, I will be tackling the weight issue when I redo the deck. :)
JacobK854 months ago
Also keep in mind, depending on your location, mosquitos like to lay their eggs in standing water. A filter, or at least a screen small enough to keep them getting through at the downspout is a must for open water collection.
When i did something similar in scotland, what i found was that if the downspout goes straight into the barrel any dirt, leaves or moss on the roof are washed into the barrel and accumulate in bottom of the the barrel in the form of sludge. so best to have some sort of filter to catch this.
CalebL40 (author)  richard.hannah4 months ago
I have this happening on the eavesdrop to prevent this :)
pgs0709474 months ago
I'm puzzled by this setup.
I collect rainwater on a largish scale, so much so that the mains water supplier (utility) thinks I fiddle the meter. The only thing I don't do with it is drink it.
Where did your rainwater run to before? Was it to a soakaway or just over the ground? In UK, it is illegal to connect surface water to foul sewers so that just leaves soakaways. Letting it run away uncontrolled is a bad idea.
Sometimes people use rainwater diverters that fit in the downpipe. These might work if you have a slate or metal roof with very little debris, but if you have concrete tiles, the moss, lichen and sand that comes off these tiles will soon block a diverter.
If I want clean rainwater, I have a small gravel and fishpond prefilter between the downpipe and the storage tanks. Any overflow goes back down the remaining connection to the soakaway, but only after filtering. If you let all the debris go to the soakaway, you will soon be in trouble with blockages.
If I just want water for plants, then all the downpipe water (no diverters) goes into the tank. The tank has a PVC 38-mm tank connector and waste pipe that connects to the original soakaway.
In the wastewater business, which I was, there was a lot of floating debris which couldn't go down any overflows. The solution is easy. Instead of just a plain tank connector at the overflow level, there was an open "T" in whatever size pipework - imagine a T rotated through 90 degrees - the original vertical goes to the tank connector and the horizontal has one opening above the water level and the other below - all water going to overflow is drawn from below the surface. The tank now acts just like a giant gully pot. It gets cleaned once a year which is a lot easier than digging out a blocked soakaway.
So far, since collecting rainwater, I have saved over 100-tonnes of scarce drinking water.
Rainwater is great for any washing, soft water, and why use drinking water to flush the lavvy?
CalebL40 (author)  pgs0709474 months ago
The rain water before this just simply went down the downspout and under the deck away from the house. It would simply just soak into the ground.I do not plan on having this being uncontrolled. Once I redo my deck, the overflow will go into a tube that will run out the back of my yard. I don't have to worry about debris, as I do have a screen preventing the debris from getting into the barrels.
Jebarstad4 months ago
Something that should probably be noted (and perhaps this goes without saying, in which case disregard this comment) is that collecting rainwater is not legal in all locales. Many of the restrictions in the United States allow for modest personal setups such as this, but Colorado, for instance, has zero tolerance for any form of rainwater collection.
Your information is badly out-of-date:

It's not completely unregulated, but it's not like you have to register your barrel purchases either.
Thanks for the correction. My reference was published just prior to that bill’s passage in 2016. Sometimes I forget what year we’re in and how quickly policy can change.
Really, illegal! regulated! First this nation was shared by nomadic indians. Then the Christian White Men came with their salves and economic system and property rights (land grants from Kings of distant lands) - jeeze, talk about "into each life a little rain must fall . . ."
Are these Democratic legislators or Republican?
Think about it - why are folks collecting rainwater? to irrigate, right? So, they are temporarily impeding the runoff, then letting it go a bit at a time.
Gee John Denver made it sound so nice "Colorado rocky mountain high" Oi Vey!
CalebL40 (author)  Jebarstad4 months ago
You are correct. It is not legal everywhere and you should check your local laws. Where I live (Canada) it is perfectly legal to do it
Here in Oregon, you can only collect what falls on your roof. Hopefully the people in Colorado will wake up and make changes to their rain water collection laws...
spielzeuge4 months ago
Really cool project and I know my wife would love to have one. Only question I have, and it is probably a dumb one so please forgive me; but I only see your downspout going into on barrel. How are you filling up the second barrel?
The barrels are connected by the black pipe underneath. As water seeks its own level, the black pipe will fill first. Then, once the pipe is full, any additional water will be divided (equally!) between the respective barrels. Now, the 'first' barrel will initially have a somewhat greater portion of the incoming water - but they will balance out. The 'lag will be dependent pon the relative diameters of the intake and crosser pipes.
Very clever! I would
Have probably slip the inlets, but you idea is far more elegant! Thanks!
CalebL40 (author)  spielzeuge4 months ago
When I redo the deck I am debating on adding a couple more using the same design
I do not see why not. It should be very scalable, and depending on where you live, the more rain you get the more it makes sense to have more barrels to fill up.
Curious, what do you mean by "slip the inlets"?
Sorry... Autocorrect. Split the inlets...
shalnachywyt4 months ago
Oh now this is clever! Why didn't you post this 10 years ago when I needed to figure out how to do this? Would've saved me a lot of dentist bills from my gnashing my teeth over how to get a spigot close to the bottom of the barrel.
Actually, having the spigot elevated a bit allows debris to collect in the bottom (below the spigot) and, thus, out of the irrigation tubing (if you use that sort of stuff). Really nice solution - wish I'd have thought outside the barrel!
CalebL40 (author)  shalnachywyt4 months ago
I didnt have my house then! Haha
GregS2784 months ago
Great idea my wife wants one! When you rebuild your deck you might want to build it out of the new plastic deck material so it won't rot! All the block will hold moisture and cause rot
use less block maybe just around the edges of the barrel! Or find a location not on a wooden structure! Just a thought good luck!
CalebL40 (author)  GregS2784 months ago
I'm going to do a stand using all wood and getting rid of the bricks. This was more of a temporary solution for the time being
Your solution has made waves in the recycled blue barrel markets across the globe! They, heretofore, sold at a discount to those with removable lids. Turning the thing Upside Down was the elegant solution - along with the idea of putting the Rain Water into the barrel's bottom where a liquid tight seal is not essential.

Also, those large valves are an issue. They are expensive, difficult to turn and restrict the balancing flow from the primary barrel into the secondary barrel (and the effective pressure at the 'tap'). Best to use the largest possible 'connector' piping that will fit and use a reducing T-adapter** in the center to get to the hose bib valve. As well, the two Hose Bib Valves add expense where one would do nicely using a 'Y' Splitter (Item#63148 $4.99) or a 4-Way Splitter (Item#9437 $9.99)

Also, consider elevating the barrels more - helps with water pressure which may be needed or just nice with a Drip Irrigation System and helps with attaching the hose(s) if the spigot is waist high.

And one more thing - a Leaf/Debris Deflector or similar device to filter our debris that will clog or interfere with your small outlet and valve mechanism. Aluminum window screening works well.

** I could not find one at Home Depot, so a 3 in x 3 in x 3" wold work using a couple of reducing bushings to get to the 3/4" for your hose bib. Bt, I did find "Charlotte Pipe 3 in. x 3 in. x 2 in. PVC DWV 90-Degree Hub x Hub Elbow with Lowheel Inlet Model# PVC003030800HD " which would allow you to exit left or right (to your hose bib valve - even Mo Elegant!.
CalebL40 (author)  charlessenf-gm4 months ago
I tested the flow at this height and it has just enough pressure to water the garden. As this is not the final location, I will be elevating it more we I redo the deck. The valve will end up being closer to chest height at final location. The eavesdrop actually has a debris filter already.
dleland714 months ago
Great idea and instructions. I might add one observation, be aware that your setup of two 55-gallon barrels full of water and your brick supports will likely exceed 1,000 pounds in around 8 square feet of floor space. Make sure your deck support structure is up to the task.
CalebL40 (author)  dleland714 months ago
Absolutely! It's been raining here alot lately and got them filled in a 2 days. Been solid since. When I redo the deck, I planning making extra support incase I expand to more barrels