The right way to water

Features - Irrigation

Getting the most out of irrigation heads and nozzles takes a number of steps by the contractor.

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October 13, 2020

Photo courtesy of Design Engineer Irrigation Consulting

Hopefully, no landscape professional tackles an irrigation system installation with the end result being unacceptable to the client. But alas, it does happen.

“We definitely encounter some installs where you just shake your head and wonder ‘who installed this’ and ‘what in the world they were thinking at the time,’” says Scott Dalton, Florida operations manager for Landscape USA. He cited common issues in such bungled jobs as nozzles with mismatched precipitation rates, and incorrect height spray heads for the type of turf or shrub area.

According to Dalton, if an installation contractor does not utilize flex pipe or swing joints, it can create long-term problems with breaks and repairs for the homeowner or client. Installing the incorrect heads or nozzles can lead to significant water usage or waste as well.

“Understanding the water supply is very critical; if it is regular potable water or is supplied by a municipality of a reclaimed system,” he says. As for irrigation maintenance, tilted heads, overspray, low heads, blocked heads, mixed heads and clogged nozzles are some common problems, along with wrong nozzle installation.

“Common sprinkler problems on rotors would be that they stop turning, the seals wear out, or the arcs come out of adjustment,” says Brian Vinchesi, president of Design Engineer Irrigation Consulting.

Vinchesi says landscape/irrigation professionals should “look for a good seal and a variety of fixed arc nozzles.” Some companies, he explains, have products with few fixed arcs, which forces the use of a certain type of nozzle. Those nozzles, although convenient, do not have the uniformity of fixed arc nozzles, nor do they match precipitate as well.

Clogged heads are another common problem with irrigation systems. “There are many reasons a nozzle or spray head gets clogged,” says Guillermo Rodriguez, a field supervisor for True Lawn Care. “If lateral lines aren’t flushed correctly during a repair, debris goes through the line and clogs the nozzles or spray heads. Another reason nozzles get clogged is from minerals in the water. Over time, too much salt and calcium in the water causes a buildup and clogs the nozzles. Using reclaimed water in the irrigation system can cause lots of problems, like algae buildup.”

Rodriguez says he frequently sees “unprofessional” landscapers installing the wrong nozzle or spray head.

“If the system has the wrong nozzle or spray head, it can cause overspray onto sidewalks and parking lots, or bad water coverage, and it wastes water,” he says. The sprinkler nozzle or head needed depends on the type of irrigation system being installed, the coverage being called for, and what is being watered. “If you need to irrigate a large area of turf, rotary sprinklers work best because it has a longer range in distance and can cover more,” he adds.

“Trouble can occur when head spacing requirements are not followed by installers,” says John Castanoli, owner of Central Lawn Sprinklers. “Most manufacturers recommend that heads be spaced at 50% diameter of throw, which means each head will have to spray up to the next head not the arc of the head.” Proper flushing of spray heads prior to nozzles being installed is imperative, he says.

“If the system has the wrong nozzle or spray head... it wastes water.” Guillermo Rodriguez, True Lawn Care

Castanoli recommends that the last sprinkler head and fitting on the line not be installed until a full flush is performed through an open pipe prior to the installation of the head. After all heads are installed, and while water is flowing, install nozzles closest to the zone valve and “work your way to the end heads” “Don’t forget to install screens (just about all manufactures supply a screen with each nozzle),” he says.

Spray heads are generally available in a stationary shrub model, while pop-up heights come in 2, 3, 4, 6 and 12 inches, Castanoli says.

“If you are watering turf you need to choose a pop-up high enough not to be blocked by the grass height. For average turf heights we find 4 inches adequate. However, if you are using nozzles that have a trajectory below 20 degrees, you should use a 6-inch pop-up head.” Stationary spray heads for watering shrubs can be installed above or below the ornamental plants.

Dalton says there are several advancements in irrigation systems, some of which include built-in check valves to prevent low head drainage and rotator/rotating nozzles to provide an even, slower watering rate.

Daniel Stagg, regional vice president South East for Landscapes USA, says each irrigation system “can be different from the next.”

The size of the job, areas being watered, water source volume and plant material affect the type of head and nozzle that should be used.

“There are some really good rotating nozzles that help cover larger areas,” he says. “Smaller areas where reduced runoff and over spray need to be provided for can be accomplished by using correct nozzles and spacing.”

The author is a freelancer based in Connecticut.