Did you read this one? Most of these are designed to be used with a municipal water supply.

irrigation tutorial

Thanks..I will read it..lots of info...one especially for gravity flow systems!

In my experience, you need water pressure to make all the commercially available drippers, etc. function properly. I "think" that even soaker hoses need a minimum of 20PSI to deliver water uniformly throughout the length. How far "down the hill" is the garden from the spring? 27.7 inches of water column equals 1PSI. I suppose you could "rube goldberg" a plastic hose and drill or punch holes along it, however, the end that is connected to the water source would get most of the water and the other end would probably be dry. Connecting both ends of your "soaker hose" to the water source would help offset this. IMHO, I'd get an inexpensive pump and use it for watering. Also, spring water isn't exactly sediment free, you'll need a filter or whatever you're using will clog, Here again, filters need pressure to function so you're back to an inexpensive pump.

Good luck,

Gravity fed irrigation is a whole other ball game than pressure fed irrigation and the norm, by far, is pressure fed. So yours is going to require a very different set up then most work with unless you want to get into installing pressurized storage tanks between the spring and the irrigation set-up. That gets expensive.

You might be better off working with old fashioned gated trench irrigation (aka Furrow Irrigation) rather than pipes, hoses, etc. Lots of Furrow Irrigation info available via Google.

Dave

Yikes! I might just stick with the garden hose!

My house is almost a half mile down hill from the spring, believe that or not! Dug by 2 ditch diggers during the depression for a sack lunch and 1 hot meal a day until finished!

I have plenty of pressure for running my appliances, and as for a filter, I have a whole house sediment filter, but I have by passed it for the garden water. It wouldn't take much to reroute the pipe back in through the filtered water if needed.

I think I might just experiment with an old hose and an awl to poke some holes in it first, just to see what happens along the length as far as pressure and see if it's reliable all along the length of it. Thanks for the help, everyone!

Like was exmar said...

The problem with only gravity based drip two-fold. If the outlets are not pressure-activated, then all the water will drip out of the lower outlets and any that are slightly higher will get nothing. On the other hand, if they are pressure activated, then the pressure might not be enough to trigger them.

In some sense, municipal water is also gravity fed, only that the water tank is pretty high relative to the outlet and gravity generates enough pressure. In this case, your pressure might be enough?

I use gravity feed for my garden. If you want to lay drip lines and all of those other fancy attachments for shop bought irrigation you need to find out the litres per minute where your garden tap is.

Get a 9 litre bucket, run the tap on full and when it is running fast fill the bucket and time it to see how long it takes to fill then work out the litres per minute. Here is the formula

Litres per minute = 9 litre bucket x 60 seconds

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Time to fill the bucket

So for the first line 9 x 60 = 540

Time to fill bucket say 10 seconds

Divide 540 by 10 seconds which means that you have 54 litres per minute.

Now if a sprinkler uses 2 litres per minute you can have 27 of them. If a dripper uses 1 litre you can have 54 of them. Or you can mix and match, using what you want to as long as the total does not go over the maximum of your litres per minute.

(If you use gallons or pints change litres to what you use. The fittings from a shop should tell you how many pints? of water are used a minute)

Now having said all of that, I don't use the shop bought attachments! Instead I run alkathene (low pressure irrigation pipe) under the mulch and with a fine drill bit, I have drilled holes where I want the water to come out, effectivly drip feeding each individual plant. If you do this, make sure that the holes are on the side of the hose and not the bottom so that the little holes do not get clogged up when the hose is turned off and there is a back suction. Also I do not have any lines that have an end, instead they all join up to form a grid - this also helps to keep the presure equalised. Those lines that run around my garden are flat - there is not any slope there.

One other thing to get the pressure as high as possible, I use 25mm main line to my garden tap - it is not until the hose on the tap that the line reduces to 15mm which helps with the pressure. I used to reduce the 25mm line feeding the tap connection to 15mm just before the connection, but when I changed it to 25mm going into the tap connection the pressure from the garden hose increased :D

If your garden tap is not right next to your garden, extend the line and put one in - as the longer you have water running through large pipes, the better the pressure at the other end.

Gravity feed is brilliant and works well. It is easy to add in lines and make changes and it is such a great feeling when it works as you want it to. My tanks are ony about 100m away from the garden. Good luck!

nzcountrybumpkin..thank you..just the kind of info I was looking for. I am confused about 1 thing, though..you said..."o I do not have any lines that have an end, instead they all join up to
form a grid - this also helps to keep the presure equalised.".....how does that work...? They just go in one large square or rectangle? Am I understanding what you meant? Thanks..

You obviously have enough pressure to run irrigation. You mentioned a hundred foot plastic hose. I'd get two fifty foot soaker hoses and a "Y" connector to join them, attach your "supply" piping to that and you'll get a more uniform distribution. Soakers are cheap as is the connector and play around with that. Indiscriminately punching holes with an awl will give various sized holes resulting in "mudholes" and dry spots.

As you're using spring water for your house, presume you've had it tested as by definitiion it's surface water. Note: testing by the local health department only looks for things which would occur if someone's septic system is too close, doesn't look for other types of contaminants which could be in surface runoff. If you haven't, suggest you have a more comprehensive test done.

Good luck,

Exmar...it is an underground spring, with pipe underground running downhill to the house. I've live here over 25 years..we had it tested when we first bought the house for many things..I can't remember now what, but I know lead was one of them..so it must have been a fairly decent test? There is 600 acres of undisturbed land up behind me, no homes, nothing but fields and woods,si I'm confident that nothing manmade is in my water, at least!

As for punching holes with an awl, I have some scrap hose, I was just going to experiment, it wouldn't be final configuration...but I get what you're saying.

t-tapes work with 10 lbs of pressure and they drip evenly along the whole line. punching holes with an awl will work for probably the first few holes from the source.

Sounds like you've got it covered, but retesting might be a good idea at some point. Been on this and other forums a long time and am continually surprised at the naievte of some questions asked so tend to err on the side of "too much information." :-)

When water is introduced to a soaker hose, etc. it is at it's highest pressure, as it flows along and loses water through the holes, etc. pressure decreases until toward the opposite end it's almost gone. Pressure forces the water out, so one end will be much wetter than the other. That should explain why feeding from both ends or two short hoses work better than one long one.

My garden is on a gentle slope with the rows running across it. Dig down about 8" and you find "hardpan" so I use that to help watering. I put a soaker hose across the top and let it run for a couple of hours, then move it down three rows and do it all over, etc. Next day, the moisture meter says it's pretty uniform. Water seems to travel downhill under soil crust or mulch. and it's at root level where it's needed, not on top of the soil or on the plants where it evaporates. 'Course, you're not paying water bills so that's not a concern.

>> Donna R(5), Glad to be of help. Anyway I was trying to think of how to explain it as I can not get a photo at the mo as the irrigation lines are not in place - just doing a new garden - so here is attached a rough picture of the plan. The blue lines are the water flow, the pink are the connectors - a mix of Elbows (the corner ones), and Tees and the Cross (4 way) and where the black line is is where the hose connector goes.

So the water flows all ways and will equalise itself instead of just running along the top line (where the hose is) then down the lines and stopping at the bottom line like the next pic.

The squares at the end of the lines are the stops. As my long lines are only 3m (about 10ft) I do not have the line going across the middle like in the top picture.

The hose is short and right there also is the seaweed fertiliser barrel so every now and again I just change the tap hose to the seaweed hose and all plants get their seaweed fertiliser delivered the same way!

I also run everything on timer so I do not forget to turn off the hose and use up all of my tank water or seaweed fert in one go!

Feel free to ask for any other clarification or anything else that you may want to know :D

Got it! Thank you!!