Drip Irrigation from rain barrel anyone??

Hey, folks!

Say, does anyone have any tips for setting a drip irrigation system up using a rain barrel?  In one patch, I presently use a system I purchased thru DripWorks and couldn't be happier.. but I have access to pressurized water there.  I've torn up a patch a little further out in the field and would like to be able to irrigate once I plant it out with brassicas.  I'd likely tie up all my garden hose if I tried to run water from the well out that far.  The site has a little bit of grade to it.  I think I could achieve a 4-5' elevation difference by setting a 55-gal barrel above the brassica patch.  I was going to punch a hole thru the barrel for a spigot and then basically run the same sort of system I run off the well.. particulate filter, 10psi pressure regulator, and then 1/2" mainline w/ DripWorks drip tape (I think it's 5/8").  Am I missing anything?  I'm not worried about getting water out there in the barrel.. I can use my tractor w/ pallet forks for that.  If additional elevation is necessary I thought about putting 4 small posts in the ground, reinforcing them to one another, and so making a raised platform that I can set the barrel on top of.

Let me know what you think!  Gosh I like this site.. too bad the rest of the Internet can't be this cool.

Hi Adam,

Glad you found Dripworks.  Usually I have to direct people there first, but since you are familiar with it, I can help you a bit more.

So 5’ elevation gives you about 2psi pressure which is enough to get an even(ish) run from their 1/4 inch non-pressure compensating drip line.  It won’t be a terribly long run and it might not be a completely even flow, but it should do the trick.  Alternatively you could use some of their non-pressure compensating emitters.  Unfortunately at such low pressures, I am afraid that pressure compensating emitters/drip line is just not going to work.  But don’t get discouraged, they have some emitters that work as low as 0 psi.

I hope this helps,

Eric

This is a great article.  This girl did the homework for you.
https://maximumoffgrid.com/gardening-methods/solar-powered-drip-irrigation-system/

Most drip irrigation systems are based on pressurized water delivery.  You are looking at passive water delivery so there are a few things to consider.  
Head pressure, simply stated, is the weight of the water in a line and in a reservoir, but, mostly in the line.  
Most irrigation emitters are pressure compensating.  This means they create turbulence in the emitters which slows the flow of water within the emitter to emit the amount of water specific to that emitter.
Distance from the water source to where the water is needed is also critical because the farther the distance the greater the friction in the lines.  Even the 1/4 delivery lines have friction that needs to be taken into consideration.  Passive flow systems will be impacted to a greater extent than pressurized systems.
Friction in the lines is probably the greatest single "bump" you will have to overcome.  A solar powered pump as described above eliminates all the guesswork.

I will tell you from experience that you need not re-invent the wheel here.  The passive approach is best served if you have a large volume of water delivered to where it is needed.  In other words, deliver the water to your garden site in as big a pipe as you can, then deliver it to the plants via the drip system.  Do not use a 5/8 garden hose to deliver the water; not enough volume and too much friction.  Go instead with a 2" system.  The ubiquitous irrigation system, or the acequia, in the desert southwest is the prime example of passive irrigation where huge volumes of water are delivered for the irrigation of fields.  Lots of times we oppose ourselves, or outsmart ourselves when it comes to doing things. Try not to do this.  Go with a little research instead, like the gal in the link above.

While I have taken it down for a good cleaning, I elevate a 150 gallon tank on a platform of concrete blocks.