Irrigation Information

Low Flow/Low Volume Irrigation

In residential settings, the most common, most affordable, and easiest to install low-volume irrigation systems are drip systems. (Note - subsurface irrigation systems are also permitted, which use drip lines installed below ground but these must be put in place before the area is planted and are generally used for commercial crops.)

Above-ground drip systems can be installed by homeowners and do not require professional landscapers. Please refer to the guides below. Drip systems utilize ¼-inch or ½-inch tubing fitted with tiny plastic emitters that allow water to drip out at a regulated pace without clogging. The tubing is laid out on the ground to snake around and among plants and trees and deliver water into the soil at the roots of the plants and trees. You can buy the tubing either pre-punched with emitters factory-installed under the surface every 18 inches, or unperforated, which requires you to punch the holes (with a small punch tool, available with the tubing) and attach the emitters to the outside of the tubing yourself.

It is not difficult to punch the holes and push the emitters into the tube at the base of each plant. Unperforated tubing used in this way allows you to customize a system to your own layout and to connect sections with tubing where you don't have plants. Some companies also sell soaker hoses, laser-perforated rubber that weeps water into the soil without emitters.

Example of a Soaker Hose

Example of Drip Irrigation System in Landscaping

Low flow or low volume devices, also known as Micro-irrigation emission devices, are defined by the 2014 ASABE/ICC 802 – 2014 Landscape Irrigation Sprinkler and Emitters Standard as follows:

“An emission device intended to discharge water in the form of drops or continuous flow at rates less than 30 gallons per hour at the largest area of coverage available for the nozzle series when operated at 30 psi, except during flushing.”

They include Drip Emitters and Microspray devices.

Drip emitters have “a flow rate less than or equal to 6.3 gallon per hour when operated at 30 psi, and are designed to dissipate pressure and discharge a small uniform flow or trickle of water at a constant discharge rate.” They include drip line emitters, multiple outlet emitters and point-source emitters.

Microspray devices have one or more orifices to convert irrigation water pressure to water discharge with a flow rate not to exceed 30 gallons per hour at the largest area of coverage available for the nozzle series when operated at 30 psi. Microspray devices include microbubblers, microspinners and microspray jets.