How to Build a Drip Irrigation System
Building your own irrigation system is not for everyone, but it’s not as hard as you might think! All you really need is determination and a good plumbing/irrigation supply store. I love my local BJ Plumbing–they are experienced, helpful, and they carry quality parts. While you can buy irrigation supplies at a discount home improvement store, I don’t recommend it. The quality of some of the products is not as good, and the advice is hit and miss.
The first part in your irrigation system is a valve dedicated to your garden. If you don’t have a separate valve, you’ll have to use one of the methods described above. This is because you cannot put a low-pressure drip system on the same line as a high-pressure sprinkler system.
Here’s what a valve looks like:
You can see I have four valves in this box. The middle right valve is for my gardens on the west side of my house. The next part is the pressure reducer. Here is one of those:
This particular part includes a filter in it–if not, you’ll need both a pressure reducer and a filter. Every spring you’ll want to clean out the filter. To connect from the valve to the pressure reducer, I suggest you get some advice and parts from the plumbing supply. It’s a little complicated to explain it (though easy to do) and depending on your equipment you will need different supplies.
Now we get into pipe. There are three kids of pipe I use in my irrigation system:
Funny pipe is really strong and thick, and it would be used somewhere before the pressure reducer, depending on how you built your irrigation system. You may not use it at all.
Drip pipe is the same diameter, but it is much thinner. Finally you can see the small drip pipe with emitters built in.
So, after the pressure reducer you put the drip pipe, to a drip pipe connector. They can be elbows, or tee’s like this:
Then, you create a network of pipe to cover the garden. I’ve done two versions of this. With the first, I ran drip pipe across the top of the bed, and then down the sides, and finished with a figure-8.
In between the drip pipe I used small pipe with built in emitters, connected with small connectors. I used the punch to poke a hole in the drip pipe, then popped in the connector. It helps to wear gloves when putting all of this together. Just a little easier on the hands! It looks like this:
Here is a picture of the finished product:
If you look closely you can see my valve box, then pressure reducer, drip pipe, t-connector, drip pipe down the sides ending in figure-8, small drip with built in emitters running between. You don’t see the bottom left connector–it is also a tee that uses drip pipe to connect to the next garden.
I found with this setup it was hard to get all the small drip pipe even, and they don’t like to stay where they are. It also felt like the corners and edges by the large drip pipe were not watered evenly and predictably.
So, this year I “upgraded” to this system. I didn’t use any small drip pipe (which saved $), but ran 3 drip pipes, one down the center, and the other two centered between that pipe and the sides of the boxes. At the bottom I connected them with elbows, so it’s a closed loop. I punched holes, and popped in my drip emitters:
You can choose different flow for the emitters–how many gallons per hour. By choosing different emitters, you can provide for the different water needs of each plant. It’s not easy, but it is possible to remove these and switch them around.
The final product:
I love this system because it’s rigid and stays in place fairly well. If I do need to anchor it, a few key spots is all it takes. I haven’t tested it (I just built it!) so I don’t know how well and evenly it waters. I’m hopeful, though!
If you have built an irrigation system for your garden, I’d love to hear about it! Describe what you use, and the relative advantages and disadvantages.