distribute water (with no pressure) over a gardening bed through a pipe

Hey everyone,

I am stuck with a problem and I don't see the solution behind it yet. I need help.

I gather rain water from a roof in a pipe. I then want to uniformly distribute the water over a gardening bed.
The water has no pressure.

How can I do this?

If I use a pipe and dig holes in the pipe each time I want the water the water to fall down, the water flow is not spread over all the holes, but it can go totally through the first one or two holes.

Any idea ?

Thanks

Hello Louis,

I had a similar problem which I solved by making sure that the distribution pipe in the garden was perfectly level and with the emitting holes lined up straight on the top. I used 2" pvc for the distribution pipe and installed a drain valve on the bottom of the pipe so that water wouldn't sit in the pipe between waterings.

Steve

Perhaps a "seep" pipe (sintered rubber, I.E. soaker hose) would fill the bill. you need at least enough pressure to overcome frictional losses, or it will just lay in the pipe.
If nothing else a little 1/25th hp circulating pump (like those used for hydronic heating systems) are very easy on electrical draw, and will provide the ten pounds pressure to evenly distribute water from a reservoir (depending on how extensive your distribution system is!).
Finally I don't know how high your storage system is but water develops 1 lb pressure for every 2.6 foot of drop,
even a 4" pipe to a 10' high rain gutter creates 3.7 lbs when its full...
if your garden is 30" lower than your storage tank is a whole spaghetti network of 1/4" soaker hose teed off of 1/2" distribution pipe can do a wonderful job of even distribution.

Hi
Thanks for your answers !

Steve, is my scheme (attached) what you are explaining ?

Red : I think I understand what you mean. However my water tank won't be higher than two feet so the pressure will be super low. Would it be enough two soak the water out of the seep pipe ?

Perhaps use smaller drain holes and slope the pipe downwards just a tiny bit (might need to experiment to find the perfect slope).

I use 1/2" black poly pipe like they sell in hardware stores for drip irrigation, then distribute it through 1/4 feeder tubes.  I do NOT use the drippers, they plug up too easily and don't flow enough with super low pressure.
The 1/4 pipe works like high speed drippers when fed water that is pressurized by 3-4 feet of elevation.

However, I'm betting that 1/8" (3mm) holes in a PVC pipe would work pretty well.  I wouldn't go any less than that or the holes will plug up with debris washed down from the roof.

Note: when drilling holes in pipe, it's much easier to make the holes larger in the future if needed, than it is to make them smaller.

This is my bread and butter technology.
My suggestion involves a number of steps
Step 1 -
catching the water in a tank and using it later when its not raining.
That way you get more water that is useful on your plants.
step 2 - Fit a valve / tap to tank with say 1 inch polypipe [ used for farm watering or garden irrigation]
lay it around the area in a closed loop, tank to tank, with a Tee at the valve.
Step 3 - using T's fit 1/2 inch poly laterals, as suggested earlier with 1/2inch poly irrigation valves at the end of each lateral.
Step 4 - With the tank full, valve open, adjust each valve until the rate of flow that comes out, allows each watering point to get an adequate share of the water.
The valve at the lowest point will be closed more than those higher and nearer the tank.
There will be not need to drain the pipe each time you use it, its happens anyway.

DO NOT ADJUST THE VALVES AGAIN once you are happy with the flow.
I have a dry climate and I set my on slow, but not that slow nothing comes out of the upper valves and the tank gets low.
I hope this helps.
Message me if you need extra assistance

Hi John, I have a couple questions about your system:

1.  Do the poly laterals connect to the loop at both ends or just at one end?

2.  How do you get water out of the laterals?  Are they open at one end and just watering one spot (a tree) or do they have emitters or holes in them along their length?

3.  Have you figured out a way to have the watering happen automatically with a timer valve?  Most/all "hose end timers" rely on high pressure city water to operate.  I've used a battery powered solar valve with good luck in the past.

Thanks!

Mike Jay wrote:
3.  Have you figured out a way to have the watering happen automatically with a timer valve?  Most/all "hose end timers" rely on high pressure city water to operate.  I've used a battery powered solar valve with good luck in the past.

Thanks!

About the only automated valve I've found that works with gravity flow water is a "motorized ball valve".  They even make some that will work with standard sprinkler valve controllers.  
I.e. it opens when power is applied and then automatically shuts off the voltage to the motor when the valve is all the way open.  Then when the incoming power is shut off, an onboard capacitor powers the motor until the valve is shut.

Yeah, hi Louis,

Your drawing is a pretty close approximation of what I set up. I kept the holes on top so that it would be more of a soaker situation, but you could turn the pipe on its side to maybe direct the water in one direction.  The main thing is the holes need to be lined up straight and the pipe should be level so that all the holes deliver water. My system had a constant but low flow, it took about 10 minutes to fill 14 feet of 2" pvc pipe.

Steve

1.  Do the poly laterals connect to the loop at both ends or just at one end?
THE LATERALS SIMPLY EXTEND FROM THE LOOP OVER TO THE TREE, THEY MAY PASS OTHER TREES BUT NOT TOO MANY

2.  How do you get water out of the laterals?  Are they open at one end and just watering one spot (a tree) or do they have emitters or holes in them along their length?
EVERY LATERAL OR SUB LATERAL HAS A VALVE ON THE END TO ADJUST THE FLOW
[url=]http://aquamatic.com.au/valve-poly-barbed-13mm-3960.html[/url]

3 Automatic valve.
NO NOT YET THE MOTORISED ON IS GOOD, BUT I FIND WALKING DOWN ANS TURNING IT ON A GOOD IDEA!!!

I hope this helps

Thanks John!  Here's that Link for others who are interested.

Do you have a good way to distribute water along a row of crops?  

What is the size of the field/
# of rows, length, and spacing
Flat or sloping land?

I have two situations, one is a garden with 25 beds that are about 2 feet wide by 25 feet long.  Crops may be a single row of tomatoes (every 2 feet) or up to four rows of onions in the bed.  The ground is slightly sloping, maybe 4" from end to end.  I usually get enough rain so my main need is when starting seeds or seedlings and I want to water them multiple times a day.

Second situation will be a greenhouse with annuals and perennials planted in the ground.  One bed 3' wide by 40 feet long and then 50-100 other plants spread around.  I really don't know a good way to water those plants since the little plants will be located wherever there's an opening and the bigger trees will need much more water.  I'm guessing your valve and dedicated line will work for the trees and I'd want a series of drip lines for the herbaceous layer.  The ground is sloping about a foot in 40'.

I would look at a pressurised system, with micro sprays.
Along the top of the beds run 1 inch poly with 3/4 inch laterals running down each bed for the full length, the far end of the 1 inch pipe would go down the far edge of the bed along the bottom and back to the start.
This will ensure minimum pressure drop across the system.
Then install micro sprays, with risers to suit the crop, say 8 inch for a start.
You would be wise to put a filter at the start to reduce the risk of the sprays blocking.

In the green house could an overhead system be installed?

webpage
This is a web page with all the parts you would look at using.
Let me know how it goes please?
regards