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Irrigating Drip by Drip

| Drip Irrigation - Low Flow

There’s a low, rumbling sound off in the distance. Can you hear it? That’s momentum building. It’s the sound of something caged that can hardly wait to be let out. It’s the sound of one era coming to an end and a new one just beginning.

Unless you’re been as buried as an irrigation pipe for the past five or six years, you know that we’ve been in a long, hard recession. New construction and housing starts have been almost nonexistent. But now the economy is starting to roll again. It’s about time!

New single family housing starts are the highest now that they’ve been in the last five years. Like a thoroughbred out of the gate, all that pent-up demand is beginning to come charging forth. You can ride that trend to the winner’s circle by getting behind drip and low-flow irrigation in a big way. There’s a big payday a-comin’ for contractors who will do just that.

“Won’t there be just as big a demand for conventional sprinkler systems?” you may be asking. Of course there’ll be some. But remember, we’re talking about new construction here. Increasingly, states and municipalities are mandating that new developments must be irrigated by drip or low-flow systems.

This is especially true in the thirstiest, most irrigation-critical states, such as California, Texas and Arizona. And many of the Midwestern states that just experienced the searing summer of 2012 are joining them. Growing concern over climate change and a general trend towards greener landscape practices are fueling the low-flow fires.

“In some cases, drip irrigation is legislated or required by regulations,” said Todd Polderman, product marketing manager at Hunter Industries in San Marcos, California. “For instance, California Assembly Bill 1881 mandates the use of drip irrigation within certain distances of hardscape.”

“Some state and local authorities are now mandating drip irrigation because it saves so much water,” said Mauricio Troche, director of sales and marketing, landscape division of Netafim USA, located in Fresno, California. “In fact, in areas that have experienced water restrictions, customers who had drip irrigation systems were still able to water their lawns.”

In some areas, water utilities are encouraging the conversion of conventional irrigation systems to lowflow ones by offering rebates. This presents a great opportunity for contractors.

Drip conserves water

Why drip? Two words: water conservation. “Conservation is the key thing that comes to mind when people think of drip irrigation,” said Troche. “We’ve seen research that shows that low-flow saves 30 to 70 percent more water, when compared to sprinkler systems.”

It just makes common sense. Instead of throwing water into the air, hoping some of it will hit the right spot, you’re targeting it just where it needs to go. “Sprinkler systems put out water measured in gallons per minute,” said Stuart M. Spaulding, CLIA (certified landscape irrigation auditor) and customer and technical service manager for DIG Corporation in Vista, California. “A typical residential, small turf area system might have a flow rate of ten gallons per minute. But in a typical drip system, flow is measured in gallons per hour. That’s how much slower they are.”

When designed and installed properly and used in the correct application, drip can be a highly efficient irrigation solution. With drip and low-flow irrigation, water is immediately available to plant materials’ root zones and isn’t wasted through evaporation, wind, overspray, mist or surface runoff. Where water is costly—and let’s face it, it’s getting more costly every day—saving water is saving money.

“Not only is it better for avoiding disease, it’s a better method of delivering water,” said Chase Erwin, business development manager for Turftenders, Inc., a full-service landscape company in Raleigh, North Carolina. According to Erwin, “Drip is a very, very precise application of water—slowly, right where it needs to be, at the root ball.”

“Here in North Carolina, we turn irrigation systems off in November and back on in April,” says Erwin. “I’ve noticed that some contractors, once they turn the systems on, tend to not pay attention. It’s kind of a ‘set it and forget it’ mentality. Very often, when our company takes over a contract, we encounter plant material that’s matured. Sometimes it’s even started to grow over the sprinkler heads. But once that plant material is established, it doesn’t need irrigation anymore. The first thing I do is suggest converting to drip.”

“Another advantage of drip is that you eliminate overspray,” said Christine Canepa, senior product manager, landscape drip irrigation for Rain Bird in Azusa, California.

“Overspray by sprinklers on a wood fence decreases its life by many years, and water on stucco or concrete leaves unsightly calcification marks. It can destroy stucco completely.”

So why doesn’t everybody use drip and low-flow? Some contractors are resistant to the idea of using drip, or even learning about it. There are several reasons for this.

“Some of it is the fear of trying something new,” said Troche. “The other issue is their memory of the way it used to be done.” He explains. “You’d see this spaghetti tubing strewn all over someone’s yard. Once the installer had finished the job and the maintenance contractor or homeowner started raking, the tubing would fly off or animals would chew on it; the emitters would fly off. That’s what originally gave drip a bad name.”

Resistance Persists

“Irrigation is a very generational business,” said Canepa. “When you’ve been doing the same thing the same way, year after year, people can be resistant to change that. But what’s happening now with legislation and regulation is helping contractors navigate towards acceptance. It’s a slow adoption process. I can tell you, though, that the younger contractors are looking seriously at drip. They are more open to change.”

“I think reluctance to accept drip irrigation for the industry at large stems not from a lack of understanding, but rather a belief that drip is a less reliable solution for the long haul,” said Polderman. “Many contractors have told me that the upfront installation cost and long-term maintenance cost of drip systems steer them toward traditional overhead systems. However, drip may be the only possible solution in certain circumstances.”

Another objection some contractors express is that clients can’t tell if drip systems are ‘on.’ “It’s almost a conditioning thing,” said Canepa. “People like to see the water, or they think the plants aren’t getting enough.” To solve that problem, Rain Bird’s drip systems have indicators that pop up when the system is on. This may simply be a matter of education, of reassuring the client that if his plant material looks healthy, the system is working properly.

Resistance to acceptance of drip irrigation may depend on what part of the country you’re in. In Roseville, Minnesota, the Albrecht Company has been installing drip irrigation for 52 years, for both commercial and high-end residential clients. One of owner Dwayne Albrecht’s first drip clients was the 3M Corporation. “They came to me and said that they’ve got to keep the water off the sidewalks (at their corporate headquarters), because they were afraid of lawsuits from people slipping and falling.”

He continues to see the commercial side as the biggest area of growth in his company’s drip business. “What’s driving that business now is that these commercial clients don’t want overspray on their property. Politically, it’s bad P.R. for people coming to do business with them to see all that water going over the curb.”

Drip and low-flow defined

Let’s define our terms. Drip, low-volume, and micro irrigation are terms that have been used interchangeably, but they’re not quite the same. All of them put out a low, slow volume of water at low pressure at or near plants’ root zones. The entire low-flow world is made up of a number of different kinds of equipment that can be mixed and matched in the same landscape. You can even combine low-flow or drip equipment with conventional sprinkler systems.

How does a drip system work? It allows water to flow through flexible tubing. This tubing can be laid above ground, right where the shrubs or flowers are, or it can be buried underground or under mulch. If the tubing is placed above ground, in-line tubing can have emitters molded into the tubing. You can then place the emitter right at the base of a plant.

If installed underground, usually a smaller orifice tubing is attached to the main tubing and brought up above ground and placed by the plant. An emitter is then put on the smaller tubing.

Emitters are the devices used to deliver the water at set rates of flow. That rate of flow can be changed by the needs of the plant material. For example, there are emitters that allow water to drip at one-quarter of a gallon per hour; change the emitter and you can get a drip at the rate of two gallons per hour.

For denser planting areas, small spray jets called micro sprays, micro sprinklers or micro bubblers are used, connected by flexible tubing. Water is delivered at low pressure, slowly, right at root zones. A wide array of diameters and sprinkler patterns are available, and the heads are adjustable.

“We use microsprays for annual beds, like around the signage in front of the grand entrance to a housing development,” said Erwin. “They can also be used in container gardens.” Green roofs and green walls are ideal applications for drip and micro spray.

are machines available that will cut a small trench, two to three inches wide, and as far down as six inches,” says Troche. “You can backfill, using the native soil and add some amendments, and use a compaction wheel over the top.”

Subsurface Irrigation 

Drip may not be the answer for every application. “It’s not the best thing to use on turf,” said Spaulding. Not everyone would agree with him about that. You can drip-irrigate turf using the somewhat newer technology of subsurface drip line or subsurface irrigation (SSDI). Just as it sounds, this is drip tubing that’s installed under the surface of the soil.

It is much easier to install before sod is laid down. SSDI’s popularity is growing for both residential and commercial turf irrigation, according to Troche.

Installation and retrofitting

It depends on who you talk to as to which is easier to install, conventional or drip irrigation systems.

Erwin thinks drip and subsurface systems are actually easier to install. Whether you’re installing underground pipes or tubing, you still have to trench.

As for converting sprinkler zones to drip, some manufacturers sell conversion kits that can make it as easy as unscrewing one component and screwing in another. You can install SSDI on existing turf. “

There Maintenance—easier or harder?

Some contractors believe that maintaining a drip, lowflow or subsurface system is harder than maintaining a conventional system. Not if you ask Erwin. “When you have sprinkler heads, you’re going to spend more time and money repairing or replacing those components than you will with drip.”

“With the drip systems we’ve installed, it’s sometimes years before anyone tells us, ‘Hey, there’s a problem.’” He concedes that systems can become clogged; however, regular flushing should take care of that. In general, if droplets of water are coming out of the emitters, there shouldn’t be too many issues. “We don’t get a lot of calls to come out and fix drip systems. This might be the one case where you really can almost ‘set it and forget it.’” “I would say that it requires a little more care when it comes to the maintenance of a drip system,” says Spaulding. “With a sprinkler system, especially if you have a broken head or pipe or something, it’s usually pretty evident by the geyser shooting up in the air. Or you’ll see a washout or erosion someplace. But if a dripper or emitter gets plugged up, unless you’re really paying attention, you aren’t going to notice that. You might see a stressed-out plant or something. It takes a little more time to find it.” All you need is a little bit of training to know what to look for.

What about root intrusion? Different manufacturers use a variety of means to keep them from invading their systems. Rain Bird uses a small piece of copper in their emitters that gives off ions. “It’s like cauterizing the tip of a root. The ions won’t kill it, they’ll just blunt it,” says Canepa.

New technology

As for new drip or low-flow technology, there are few new things bubbling under. “We have some new dripline coming out that has a lower (environmental) footprint,” said Spaulding. “It has thinner-walled tubing that uses less raw material to manufacture and so it’s more friendly to the environment. Because it uses less energy to produce, there’s less material going into landfills or being recycled. This is something that manufacturers are moving toward.”

“Hunter’s newest products in the drip category are our fleece-based products, the Eco-Mat and PLD-ESD (enhanced subsurface drip line),” said Polderman. As he explained, unlike overhead irrigation systems that move water through the air, drip relies on the soil to do the movement. The Eco-Mat uses fleece to move water horizontally and to store water for future plant needs. It’s especially useful for green roofs that use very porous soil.

“Rain Bird has the XFCV, a dripline with a check valve,” says Canepa. “The benefit of this is that you can use it on slopes and elevation changes.” The check valve keeps the water from draining out to the lowest point once the system is turned off. There’s no waiting for the line to charge, so you can irrigate immediately. Canepa says that the XFCV has a holdback higher than eight feet. The new product will be especially helpful for slopes with retaining walls. The XFCV debuted last December.

“Netafim’s newest is the Techline CV (check valve),” said Troche. “It has our UniRam emitter inside. It’s pressure compensating, so every emitter puts out the same amount of water.” It also has an anti-vacuum feature, so you can bury the tubing, even in a muddy area, and don’t have to worry about debris being sucked in when you turn it off.

Like smart controllers, drip and low-flow will be a big part of the future of irrigation. It’s something you should get very excited about. Educate yourself about drip and watch the profits pour in, not by the droplet, but by the bucketful.

 
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