Drip irrigation systems are growing in popularity, both with contractors and their residential and commercial clients. Unlike traditional sprinkler-based irrigation systems — which typically deliver a general, even water lay over large areas — drip irrigation systems allow for precise watering that can be dialed in for each plant exactly where it’s needed.
Drip Irrigation Logistics
In drip irrigation systems, water is delivered to plants at the root level via a system of tubing and emitters. The emitters are typically positioned around individual tree or shrub rootballs or strategically placed within a bed of perennial or annual plantings.
One of the advantages of drip systems is that emitters can deliver a relatively high or low flow of water in an exact, predetermined area, without wasting water — as sprinklers sometimes can — by spreading it where it’s not needed.
Standard emitter flow rates include 0.5/gallon per hour, 1 gallon/hour, and 2 gallons/hour. By intentionally employing varied speed emitters, a skilled drip irrigation system installer can deliver optimal levels of water to each particular type of plant within a particular landscape design while reducing the property’s overall monthly water usage.
Popularity of Drip Systems
Because of their water savings potential, drip irrigation systems have become particularly popular in areas of the country that are prone to drought.
“At least 50 percent of our new installs have some form of drip, whether that's going to be tubing with in-line emitters or point-source emitters, or point-source emitters on flexible PVC half-inch ends,” says Tony Neglia with Makelele Systems Landscape Maintenance based in San Marcos, Calif.
Neglia says the proliferation of drip irrigation in Southern California has been growing in recent years — from roughly 30% of the market share four years ago to more than 50% today. He expects that trend to continue.
“I think pretty soon we'll see at least 70% of our installs go full drip,” he says. “And then as technology progresses, I would not be surprised if that's 100% of what we're installing in the future.”
Neglia believes drip systems’ water conservation properties have begun to resonate with consumers, both in terms of environmental stewardship and overall utility cost savings.
“The benefit of drip is you're getting more point-source irrigation,” he says. “You’re not getting the misting that you normally would from spray heads or even rotary type nozzles. You’re getting point-source irrigation, below the level of mulch, and it's just overall a more efficient way to water things.”
While a subterranean drip irrigation system might cost 50%-75% more to install than a standard sprinkler system, clients quickly recoup their investment in water savings alone, Neglia says.
“The cost is mitigated by the efficiency of the system,” he says. Makelele customers who’ve opted for drip systems are “usually recouping their investment, aside from any rebates they might have, within one to three years of initial install, depending on the size and scope of the project,” Neglia adds.
Many municipalities offer rebates for water-savings systems like drip irrigation — sometimes paying as much as 66% of the install cost — so Neglia always encourages customers to seek out rebate opportunities when considering their actual out-of-pocket cost.
Beyond saving money, many customers are seeking out drip systems as a way to be better environmental stewards. Because they deliver water directly to plants’ roots, drip systems are not plagued by the overspray, run-off and evaporation challenges of traditional systems.
“Many times, we have customers coming in looking for a solution to their water use problem,” Neglia says. “They know how inefficient their current systems are.”
Installation Best Practices
Neglia’s team prefers to install drip systems not just under mulch, but under the soil.
“If hoses are installed on the surface, once your mulch goes away, you see the drip hoses, and it’s very easy for them to be mistakenly cut during mowing or other landscape maintenance,” he explains.
To avoid these damage risks, Neglia prefers to install drip hoses two inches below the soil surface. He feels that’s the ideal depth to avoid surface damage and still reach plant roots effectively.
“Sometimes when projects are done on spec, we’re seeing calls for installs anywhere from three to six inches deep. But if you’re at a six-inch depth and you’re watering a one-gallon plant, you’re beyond the reach of the root system for that plant,” he says.
In other words, installing drip hoses deeper than two inches may work for established landscapes, but it’s not ideal for an initial or new landscape install.
Neglia’s company prefers to install their drip systems after all landscape plants are installed. While most companies tackle projects in the opposite order — installing the irrigation system first — Makelele teams have found placing the plants first allows them to better target their emitter placements and avoid damage to the drip system during installs.
“It’s looked at (like a) little oddball in the industry, and we sometimes get pushback from landscape architects,” Neglia says. “But to us, it makes sense to plant before we do the drip in most cases, simply from a production standpoint. We use augers to plant. The worst thing you could have is your auger end going through your drip tube.”