Rainwater Harvesting/ Gravity-Fed Drip-Irrigation systems?

Friends,

I am attempting piece together a network of rain barrels to feed 18 annual beds ,both raised and ground-level,as well as perennials vegetables and berry bushes. 10" raised beds:(4)4x25', (3)4x30'ish. grade: (4)2x15', (4)2x20', (3)2x30'.

What I'd like to do is place a few barrels near the downspouts,all daisy-chained, and tie in a few more barrels near the beds that are farther away from the leaders(source)..by having them all daisy-chained they should all fill up more or less at the same time,rather than overflowing into one another. the beds farther away would each have a barrel next to them,leveled with the ones near the gutters and tied in with hose/tubing,so water pressure wouldnt drop below adequate levels. does this make sense?

one thing i'm uncertain of is which NPC Flag Emitters to get?. 1,2 or 4 gallons per hour? . can the 4GPH be regulated with the Flow Control Valve at each barrel by leaving it half or 1/4 open ? my barrels will only be raised 2 or 3 feet off the ground, so with that low pressure ,the actual GPH flow rates on the emitters will be much lower . i really cant have barrels all over sitting any higher than that! my soil is humus/loamy/compost/dark topsoil.below that it is more clay/silty than sandy.drains well but not at all sandy. would 4GPH emitters be wasteful? could i get 1 or 2gph and simply leave it "on" almost always? or do the same witht he 4gph model.

each downspout will have a DIY First-Flush Diverter. i'll also have a system for the overflow which i saw in the latest issue of Mother Earth News basically makes a leaching-field of the garden/paths.

I put a bunch of photos on our garden page of the 3d-model i made for the garden...updated with my current ideas. gets a little crazy with tubing all over...one concern is how to store it all in the winter,if i need to roll up tubes and store in basement,or will they be fine so longs i empty everything out? Don't want tubes,fittings,emitters freezing and cracking.
https://www.facebook.com/media/set/?set=a.383896041635803.112955.222742067751202&type=3

The african and central american projects don't use emitters, cuz it takes 10-12 lbs pressure to run em.

Put a drywall screw thru the hose, so just the tip comes out the other side. Leave the end of the runs screwed out a little more than the close ones.

Morgan,
Just so I'm clear -- leave the screws in the hose?
Thanks,
Gani

i dislike this 'inability to edit posts after 24hrs' busniess... oh well.
wanted to add these up top..

Hey Matthew

I use drip on my garden here in NM. It is fed from the city tap, on 4 separate 1/2 inch runs. The tap pressure is quite high. I also do rainwater capture, but I know that this drip setup will not run all of my emitters from the lower pressure gravity feed.

Initially I ran only 2 main 1/2 inch feeds, but after adding more and more emitters, eventually the pressure was not sufficient to drive the emitters at the higher elevations. The point is that the water pressure directly relates to how many emitters you can reliably drive.

My advice to you would be to test it out. Run a 1/2 inch feed and connect up to your gravity source. Then start connecting up 1/4 inch loops with emitters as you need them. I find connecting emitters while the system is running is ideal, as it gives me a feel for how the water flow is at that exact position.

Let me know if you have more questions.

=)

Hi Matthew,

I just had a conversation with my son’s employer who is a landscaper and needs to set up a similar system. I installed a few rainbarrels this year and he came by to see how I did it. You can see a write up of it here:

http://citylivingnaturally.com/green-yard/build-your-own-rain-barrels/
http://citylivingnaturally.com/green-yard/rainwater-harvesting-system/

Like Ed, I run my drip irrigation off of the city water, and use the rainbarrels for separate watering. There’s not enough pressure to force water through the emitters. Also, even running off of the hose bibb from the house, and going through a screen filter, I have a couple emitters every year that clog. Any little bit if dirt can clog them. I saw your link to the first-flush diverter, but if bugs/leaves blow down the downspout in between rainstorms that stuff could end up in your barrels. Also, take into account any algae growth, etc. That all can find its way out to the emitters and clog them.

I like Morgan’s suggestion of the drywall screw, that way it’s more of a soaker situation. I am considering using a soaker hose on the barrels that are near a grassy area, so this is similar.

A suggestion regarding the leach field concept- instead of tapping into the bottom of the container, you may want to tap in toward the top, that way the container will hold some water after it stops raining, but will feed the leach field once it fills up. I installed some pvc connections toward the top of my barrels for overflow, and I direct that overflow to the surrounding plants. It may not be a big deal for you if you live somewhere that gets frequent rain, but I’m in the desert where it can go weeks without raining.

yup screws stay in, and adjust out to increase water flow.

A couple of thoughts, one from my own experience and another from a friend.

My friend had a few rain barrels but his house was downgrade from his garden so he hooked up a solar powered pump (Amazon for $89) to pump up to his garden. I'm not sure if there would be enough pressure for a drip system but its worth looking into.

My experience with in-line rain barrels ended poorly because my plumbing skills suck. I had leaks constantly (even with teflon tape I seemed unable to catch all leaks) and never really was satisfied with the system, when the cinderblocks shifted and the 4 55/gallon barrels came tumbling down I moved onto other projects with only mild regret. I will tell you though that most commercial barrels from car washes have two bung holes that have standard threading that you can hook right into with garden hose once you drill the middle out.

mytwocents

Personally I would avoid barrels unless you can get them for free, because per gallon they are much more expensive than the large poly rain tanks....

Agreed Tyler, my next project will be Ferro-Cement

Sandra Ellane wrote:I am considering using a soaker hose on the barrels that are near a grassy area, so this is similar.

I tried to use a soaker hose with rain barrels but there was not enough pressure so no soaking action (the barrels are about 5' higher then the hose).

thanks for the feedback all. i put the project on hold iuntil i get soem other things finished up (right now the priority is slabbing the giant hickory logs on my front lawn!)

i do have a source for free barrels,from a Pepsi bottling plant nearby,they give away the drums the cola syrup comes in. they are also more modular and scalable than one huge tank would be,i dont have space for that sort of thing,but the drums i can line up along a fence or by downspouts easily.

Leon Elt wrote:I tried to use a soaker hose with rain barrels but there was not enough pressure so no soaking action (the barrels are about 5' higher then the hose).

you must get the low/no-pressure gravity soaker hose made specifically for rainbarrels...unless that stuff is real cheap my plan will be to collect old hoses and drill holes all over em on the drill-press.


the "NPC" non-pressure compensating emitters are supposed to work with low pressure. the other ones need 10-12 psi but release water more evenly. since i'm on flat land i figure i may get away without the PC.
i'd love to tie the tap into the lines and just close off the barrels when that is running.then i could incorporate a timer on there.

at the NOFA summer conference this year i took a workshop with Lee Reich. he showed his drip system in the slides, i was kinda surprised he only uses 1 line down a 3' bed and inline emitters every 12 or 18". this was even in lettuce beds! i had though i'd need at least 2 in my 2' beds and 3 in the 4'ers. i'll try 1 in each and see how it goes. see attached pics.