Back to 4 Steps For Designing a More Efficient Commercial Drip Irrigation System Step 3

Zone Control

Irrigation systems: mechanical components and practices

by Shaye Donald and Marisol Camacho

Zone Control
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Zone Definition: A zone is the area within an irrigation system that is controlled by a control valve. This can theoretically be as small as one plant, and as large as a multi-acre field.

It is recommended to have three key components at the beginning of each zone: a control valve, a filter, and a pressure regulator.

There are many more additions that can be included per zone, but these three components are the most essential pieces when designing a system. This diagram shows the standard layout used in HGC Irrigation designs.

Zone Control
Standard Hawthorne irrigation system design with key components.

It is good practice to include a manual bypass for solenoid and filter maintenance. It is also a good idea to put the pressure regulator downstream of the solenoid valve as they are often not rated for sustained pressure.

Now that you understand the 3 basic components of zone control, let’s dive deeper into each component.

Solenoid Valves

Solenoid control valves are the piece of equipment that allows for automated irrigation to be automated! Referred to as a solenoid, globe or simply as an electric control valve, this item turns on or off (open or closed) when a signal is sent by an irrigation controller. When the valve is open, then the water flows. When the water flows, our plants are happy and watered!


A filter is the difference between having an irrigation system that lasts for 5 years or 5 weeks. The path that water has to travel through inside a drip emitter is small. Very small! Filters prevent any particulates from clogging drip emitters. HGC always recommends a disc filter with a micron size of 130 or less. Mesh and micron do not have a proper mathematical conversion rate. These numbers are commercial approximations provided by Netafim.

You might be thinking, “yeah well my water is clean, bro.” Or, “I have the purest nutrients that dissolve completely! Why should I filter my water, again?” While most irrigation systems have a primary method of water filtration, having another filter right before the bench adds a second level of protection from clogging in your drippers.

Nobody wants to put all this care and attention into designing and installing a system only to have drip emitters clog!

Finer filtration ⟶


Note: Micron and mesh are two numbers which correspond to the level of filtration that a given filter is capable of.

Pressure Regulators

Pressure regulators, well, regulate pressure. As long as the pressure before the regulator is higher than the rated set point (commonly 30 or 40 psi) then the outlet pressure remains regulated at the same psi. Since drip systems work best within a range (15-50 psi, in general) it is important to install regulators on each zone to ensure uniformity.

Note: Always double check the flow rating on the pressure regulator. These devices will only operate properly within a certain flow.

Continue learning with our next step ⟶

The Hawthorne Difference

Our team of technical experts can help not only with the specifics on setting up a drip irrigation system, but also with the holistic, complex interplay between irrigation and other areas of your grow, including nutrients, growing media, HVAC and lights. Our goal is to provide growers the information they need to make the right decisions for their facilities, the first time.

The products and advice to keep you in the game

Hawthorne Gardening Company, in partnership with some of the largest irrigation equipment manufacturers in the world, is here to help you maximize your crop’s potential with the best irrigation management strategies and information available today.

Our dedicated team can assist you in every step of the way to ensure that your system will work exactly how it is supposed to from day one.

For more information, call Hawthorne at 888-808-4826 or fill out the form below.

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