Introduction: Gravity Feed Rain Barrel Garden Watering
A few years back I installed a rain barrel & water distribution system in my backyard and it's worked so well that I decided to build on that idea and install one on the front/side of the house. The first step is to decide where you're going to position your rain barrel(s). Luckily, I had a spot next to the fence that never really grew much because of lack of water/sunlight, and was close to where I already had a downspout in the eves trough.
Tools & Materials:
Measuring tape & pen/pencil
Saw (hand saw, jig saw, mitre saw, etc)
Dremel (or equivalent)
Screwdriver (power or hand powered)
2 - 2'x4's (8' lengths)
3 - 2x6's (8' lengths)
3" deck screws
2" diameter ABS lengths
2" diameter ABS couplings (assorted as necessary)
3/4" flexible poly pipe (as necessary) & 3/4" couplings
Downspout leaf diverter
2" diameter ball valve
#8 3/4 self tapping screws (to attach to eaves trough feeder)
*** Since this involves using various tools, suffice to say that I recommend using the necessary safety equipment and taking all necessary precautions to avoid any injury ***
Step 1: Select a Good & Level Location
Depending on how solid your ground surface is, you might want or need to put something under the barrel stand.
Step 2: Building the Stand
I used a handful of left over building materials - 2x4's & 2x6's, as well as a handful of 3" deck screws to assemble the barrel stand. Start by cutting your pieces to length - for this build I needed a 24" square (two 24" 2x4's and two 21" 2x4's). Then, I added four 2x6's (each cut to 24" long) to the surface of the square just created. The next step is to attach the legs to the base of this top you just built. The height (length of the leg pieces) will depend on how high you want your barrel to be. Pros of a high barrel are greater water pressure at the end of your feeder tube, cons are balance, and access to the barrel itself. I measured the height of the eves trough, then subtracted the height of the barrel, and the distance needed to get the water from the eves trough on a diagonal to the top of the barrel (via the leaf deflector). Once you've got your legs installed, you should brace the lower part of the legs for stability. The only pieces I had left from the 2'x4's allowed me to construct a simple brace 12" up from the base of the legs.
Step 3: Preparing the Barrel & Water Diverter
There are more and more options to source a rain barrel - I found mine for sale at a farm for $25 each. Just make sure that they never contained any chemicals that would harm you or your plants/garden. The first step is to locate the lower discharge hole and cut it to fit the size of your outlet. I was using 2" ABS, and used a dremel to cut the two holes. Then, using some other ABS components, attach them to the barrel and seal with a good quality silicone sealant. The next step is to attach the manual ball valve on the lower discharge, and corresponding lengths of ABS to connect the top discharge (overflow) to the lower discharge on the far side of the ball valve. This way, if the barrel gets too full, the excess water will still enter the system and discharge away from the house (*very important, unless you'd like a rainwater swimming pool in your basement!*). You will need to cut an access hole in top of the barrel, allowing you to reach the lower discharge hole and the ability to clean out the barrel later on.
Step 4: Put the Barrel in Place, and Attach Downspout
The ease of this step is dictated by how close you are to your downspout. Make sure to allow for a leaf diverter - available in a handful of variations, I just grabbed the one sold locally. This will help keep the excess debris from getting into the system.
Step 5: Connect the Feed Lines to Your Garden
There are countless options once you get past the shutoff ball valve and overflow diverter. I opted to attach to 2"x2"x1.5" ABS pieces and dropped that to two 3x4" poly feed lines to service two areas of my yard that get a lot of sun and very little water. Other options include connecting to poly/abs/pvc and then drilling small 1/4" holes every 6" along the length to disperse the water. Two things to note here. On the drop tube of 2" ABS I have, I have capped the end but only by friction (not cemented) about 12" below the 2"x2"x1.5" tee. This will allow the sediment to collect and be manually cleaned out as necessary. Do the same at the end of the poly/abs/pvs pipe for clean out. The one last point, is that if you live in an area that has long frozen winters like we do - make sure to disconnect the system once there's a risk of freezing up, or your lines will fill with water and burst.