Rain Barrel Irrigation

Rain Barrel + Overflow

There was no irrigation to speak of on our property. And both me and my wife liked the idea of harvesting rain water for irrigation. It's free water that you can use without restriction and it's great for watering plants. So, nearly a year after we got our first rain barrel, we now have our front yard watered automatically by rain barrels. Here's how we did it.

Our first rain barrel came curtesy of my sister, who bought us a rain barrel and a rain barrel stand. It was one of those decorative rain barrels that is plastic, but it kind of looks like an oak barrel. It also had a flat back so that it can be placed flat against the house (spoiler: it can't). The flat back bulges when it's full, so placing it directly against a wall doesn't work. Fortunately, however, the ground slopes down a little from my house on the east side of our house. So, the rain barrel naturally tilts a little bit away from the house.

When we got our first rain barrel, we needed some way to harvest the rain. And... we had no gutters. However, since gutters were something on our (long) list, we put the rain barrel against the house with the intent to route a downspout into the rain barrel, which we eventually did. There was also a built in overflow dump on the top of the rain barrel. So, in the event that the rain barrel fills up, excess water will spill over into the side yard.

We got our second rain barrel second hand from my dad. He spends a good portion of his retirement gardening. So, he was able to get us a second hand food storage barrel that had a hose connection on the bottom (from the garden mafia, I guess?). It also had an overflow port on the top/side of the barrel, which I added a plug to since I planned on using a diverter instead of allowing the overflow to spill over.

Rain Barrel With Diverter

I won't get too far into the reasoning behind using a diverter on the second rain barrel. But the basic idea behind my rationale was that prior to installing the second rain barrel, the downspout it is now connected to forced water directly into a shallow french drain. And well, I wanted to keep that system in place. So, with a diverter, once the rain barrel fills up, water exits the downspout normally, which suited my needs just fine.

As far as installing the diverter... I used the Oaty Mystic Diverter. We have 3"x4" downspouts. The Oaty Mystic Diverter is made for 2"x3" downspouts. However, I found that if you invert the installation (check out the pic) then it will (just barely, and somewhat painfully) fit a 3"x4" downspout. Once I sorted that out, I cut the downspout and added in the diverter. Oatey packages a flexible tube for connecting the diverter to the rain barrel. I cut a hole in the top of one of the screw-on caps in the rain barrel, fit a plastic coupling inside the flexible tube and tightly secured it into the cap. I then screwed the cap back in and sealed it all up with gutter sealant. Finally, I connected the other end of the flexible tube to the diverter, added a little gutter sealant to that end and viola! I had my second rain barrel hooked up.

Hooking Up Irrigation Lines

Irrigation Line + Bubbler

Irrigation from rain barrels is interesting. The biggest thing you have to understand is that there is not a lot of water pressure coming out of a rain barrel; it's just gravity fed. So, a standard irrigation timer won't work (most irrigation timers rely on pressure). A zero-pressure irrigation timer is needed, instead. I used a zero pressure digital irrigation timer from Yardeen.

Also, because there is very little pressure, you can forget about a standard sprinkler setup. And you can also forget about running water up high (like over pots). Instead, I used RainBird flexible irrigation hose with bubblers and drippers. The RainBird bubblers on the stakes worked super well. The drippers... I think the jury is still out. Basically, all I did was connect up the hose to the timer, ran the hose low and added bubblers around all the plants I wanted watered. A couple of test runs with a mostly full barrel proved that this method for watering seemed to work great. 

Watering Frequency

I had planned on watering every day for like an hour. However, my dad, the master gardener (he really is a master gardener - studied at UF), told me that 15min every other day would be more appropriate and it would likely be better for my plants. So, I've got it set for M,W,F,S 15min near dusk. The good news is that as long as it rains about once every 10 days then I don't have to water my plants in the front plant beds.

What's Next?

I'm not super happy with the placement of the lines. They work, but they are pretty visible. So, I think I will put in some effort to reroute them under the house and possibly bury the lines in the plant beds. I also want to water my potted plants. I can't go over them, but I can go under them. So, I'll probably look into putting holes in the bottom of the pots big enough to run a soaker line into.

I also haven't really done anything about the back yard. However, I do have some water collection in the back. I've got a 70gal tub (for rinsing SCUBA gear) that could collect rain water and a 5gal tub that slowly releases AC Condensate into the back of the french drain. Maybe once I get my backyard sorted, I can water the plants for free back there, too.