How to Make a Rain Barrel Water Catchment System (Better)

Introduction: How to Make a Rain Barrel Water Catchment System (Better)

 For a permaculture class at our school, Maharishi University of Management, we decided as a team to build a rainwater catchment system. As it turned out, the university Sustainable Living department was already equipped with such a system, but upon our inspection, we discovered it was faulty or in disrepair in many areas. We undertook it as our project to the lean about rainwater catchment by repairing the one that already existed. So more than anything this instructable will help you to see the details of having a barrel rain water catchment system and how all the pieces fit together.

We hope this will be a helpful resource for your own endeavors to create a more sustainable and ecologically sound world by preserving and cultivating our most precious resource: water. 

Step 1: Materials and Preparation

 Because we were coming in and just reconstructing a system that had already been created, our steps were different that starting from scrap, but here I will include a list of materials you will need and the preliminary stages.

You will need: 

The Barrel
A barrel, and if a rain barrel for this purpose is not accessible a trash can or other type of barrel can also be turned into this. We used a two barrel system, but this can also be done with one barrel.

The Spigot and Hardware
A 3/4" hose bib spigot
A 3/4" galvanized lock
A rubber washer ring with a 1" diameter 
Teflon tape
Super Glue

The Overflow Valve and Hardware
3/4" brass overflow valve
Hose MIP adapter 3/4 x 3/4 x 1/2"
And the last for list items on the above list

1" hole saw or drill bit (use 15/16" for very secure fit)
Utility knife
Needle node pliers or wrench
Screw driver and 1/2 dozen screws
Meshscreen for top filter

I don't know if all of these exact materials were used in the making of our very own rain barrels, but this list is a pretty standard prep. list for any rain water catchment system. 

Step 2: Where Is Your Water Coming From?

We had the luck of already having a location to place our rain barrels and a connection to rain gutters catching rain off the roof and channeling it into our greenhouse where the rain barrels sit. It is important to figure out an energy efficient location that will catch optimal run off from the roof. Slanted roofs are a definite plus, if not must. 

It is best to have the barrels raised off the ground so that gravity can work as your friend when you are using your rain water to feed your baby plants, or do whatever else you are planning with it. 

The rain barrels had previously been resting on top of two large metal barrels, but a lot of rust and corrosion was taking place so we decided to clean the whole space up a bit and cut a large board to serve as a platform for the barrels to sit.

Extra Tip: Rainwater is a perfect pH balance at about 6.8, in the neutral zone with just a tilt toward acidity, for watering your new plant growth, starting seeds, and nurturing other plant life. 

Step 3: The Dirty Work

 The next thing we had to do was examine the rain barrels and see what their flaws were and how they could be remedied. Now, this step would generally include the assembly and some more of those technical details, but because they were not included in our process, we will only share what we know how to do best. For more help on your project there are several other instructables on the basics of building a rainwater catchment system, but we hope that the information we have to share is valuable to the areas which it concerns

Our barrels were close top barrels, meaning that there was no lid to be removed, but only small holes with mesh made of galvanized metal and secured with galvanized wire, although these were coming loose and there were holes in the mesh... Either it had been a long time since they had been made, or the maker had not been very thorough :) 

There was dirt and debris gathered on the top of the barrels, and upon inspecting the inside we discovered that they had bacteria and moss growing on the walls... time for a clean up! 

The attachment of the two barrels was also done fairly poorly and had become unsealed, as the maker had just used some sort of glue or silicone to attach rather than going on the inside and firmly securing it. So there were leaks, and when pulled, the two came completely apart. 

These were the issues we were facing, and we addressed them one at a time. First, we took apart the old system, got a mechanical saw and took off both of the tops so that we could open them up to clean out, and also go inside to secure the spigot and barrel attachment. Then we covered the whole top with more of the mesh screen, so rather than have just a little hole, the whole top was open, making the design more efficient and accessible. 

Step 4: The Finished Product

 After our clean up and alterations the system was good as, if not better than, new! 

All in all we:
Created a new base to prevent rust and create balance
Cleaned gutter
Deep cleaned barrels
Removed barrel lids
Reattached spigot and tube in a much more efficient mannor
Created new mesh filters with glavonized wire securing them
And put all together as a new system for the betterment of the university and, dare I say, the world at large (if we are thinking in a permaculture mindset that is)

We hope this instructable served its purpose to show some difficulties you may run into in the making of your rain water catchment system and improve your own system to be in seamless operation, best of luck harvesting those precious drops! 

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    4 Discussions


    5 years ago on Introduction

    I have found that if you get a piece of garden hose that will reach to the bottom of both barrels, ( make sure there is a foot of water in each barrel first) Fill the hose with water and without letting any water out submerge both ends of the hose one in each barrel it will automatically syphon water from one barrel to the other. This eliminates drilling holes in the barrels for connecting pipes.


    6 years ago on Introduction

    Here is a less complicated rain barrel kit

    I'd suggest a prefilter on the downspout like these:


    8 years ago on Introduction

    I would screen the overflow overflow pipe to keep mosquitoes out.
    They can fly in through the pipe, get into the barrel water a breed....
    and you would never know it.

    My system uses open top barrels with air tight seals and locking rings.
    I have a fine mesh screen attached on the overflow pipe inside
    of the barrel.inside the barrel. For the most part they stay clean....
    as long as your also screen the input opening of the barrel.

    One option is to use a fine mesh pool filter bag


    9 years ago on Introduction

    Probably overkill, but I put a union between the two barrels because mine are outside, and I may take them apart and put them in the garage for the winter.