Drip irrigation layout design

Drip irrigation is sometimes deceiving because unlike overhead turf grass spray drip irrigation is being applied subsurface at the root zone of the plant. Many times the only way to easily determine if it’s operating is when the zone first turns on you can hear the air being pushed out of all of the little remitters throughout the planted areas.

Two main things to consider when designing a drip zone. First which type and size of piping are you going to use. Second are you going to divide your planting area up into separate zones by plant type?

Let’s take the type of piping first. The very best way to route your drip lines is using three-quarter PVC pipe as like a mainline running underground throughout your yard connecting the separate drip areas together, then stub-up to the surface every 20-30 feet apart where you will connect with half inch flexible black poly drip tubing to run close to your plants where you will then attach the emitter to water each individual plant. The benefit of the three-quarter PVC pipe is it will remain in place as your drip foundation line and remain reliable unobstructed for many years of use. The other and more common way of doing it is simply running the half inch poly pipe from the valve throughout your planting area. Some contractors are using a larger 3/4 inch poly tubing to try to keep the water size flow larger much like the intent of the PVC method. The downside of running poly tubing throughout the entire area of your drip system around your yard is at any point the poly tubing can be pinched off or compromised by tree roots. I service and repair many drip irrigation systems where roots have crushed or damaged the poly tubing at some point.

Next is the question should you divide your planting area up into different zones for each of the the different types of plants and or trees? First if you do this it’s a lot more work and adds complexity to your sprinkler irrigation system. But it does add the ultimate in watering flexibility. The more common way of doing your drip layout is using smaller gallon per minute emitters on the smaller plants and larger or more emitters on the bigger plants and trees. This does work well and is a much more simple way of doing it with one consideration, that is vegetable gardens and or small little annual colorful flower areas each of these will benefit greatly with the flexibility of a separate valve station so these areas can be watered more frequently.

The type of drip emitters I recommend are Netifim brand made in Israel. They’re not the most expensive but over the long run have found them to be way most reliable. 2 gallon per hour for a drip emitter is standard.

Be sure to attach a 20 to 30 pound pressure reducer with a micro water filter specifically designed for drip irrigation to the discharge side of your control valve.

In the St. George southern Utah desert with its high summertime temperatures drip irrigation is very water conservation wise reducing water evaporation because of the application directly to the root zone of the plant.