Low Volume Irrigation
|By ELIZABETH LEXAU|
A growing number of property owners and municipalities are waking up to the fact that efficient landscape irrigation can play a major role in water conservation. There are several effective strategies for making landscapes more water efficient. In some cases, turf can be converted to xeriscape plantings that require less water. Smart controllers can also be added to automatically adjust the watering schedule based on how much water the landscape needs. But one of the most important strategies for water conservation is the use of low-volume irrigation.
Low volume, or micro irrigation, directs low pressure moisture specifically to the root zone of the plants that need it. It also gives each plant the optimal amount of water it needs, instead of giving plants with varying moisture requirements the same amount. In addition, drip irrigation doesnt water weeds in between preferred plants. Therefore, it not only saves water that would be wasted on weeds, it also saves on maintenance. Finally, it doesnt waste water on sidewalks, driveways and buildings, or lose significant amounts to evaporation. In an age where water is no longer seen as a free and unlimited resource, low-volume irrigation simply makes sense.
The terms water shortage and water conservation are not just about drought conditions anymore, says Rick Heenan, national sales manager for DIG Corporations commercial division, located in Vista, California. ?The fact is that there are too many people, too many developments, and not enough delivered water available.
Were at a dramatic point in irrigation history, agrees Travis Komara, president of Salco Products, Inc., Fontana, California, a manufacturer of drip irrigation devices. There is much more legislation, and there are more incentive programs in support of lowvolume irrigation than ever before, because more municipalities are experiencing success with these systems.
Watering restrictions have become commonplace in many cities across the country. Now more are starting to restrict the types of irrigation systems allowed in new construction. LEED, the Leadership in Energy and Environmental Design certification program from the Green Building Council, includes efficient irrigation as one of its recognition criteria. A growing number of local and state governments, not to mention the federal government, are making a commitment to follow LEED standards in new construction.
In some cases the carrot is talking louder than the stick. In cities such as Las Vegas, Nevada, Albuquerque, New Mexico, Seattle, Washington and many others, exciting rebate programs reward commercial and residential water customers who convert part of their property to waterwise landscaping zones. Although this is seen as cutting edge, says Komara, its really gaining strength in other communities as well because of the water savings we?ve seen.
Concern for the environment isn?t the only force driving the market for low-volume irrigation. Some contractors have been using it for more than twenty years and theyve really seen the value when it comes to plant health,? says Susan Thayer, president of Maxijet Incorporated in Dundee, Florida. Word is getting out that micro irrigation promotes more rapid growth and healthier, more luxuriant
Economic gain, for both the contractor and the consumer, is also having a big impact. Contractors are finding that their profit margin is higher when they go with micro,says Thayer. Consumer demand is also higher. Theres been a lot of good publicity regarding micro irrigation. Homeowners are educating themselves and starting to see that it?s the right thing to do economically. Theyre asking for it because they know what it will do to their water bill.
The bottom line is that the market is booming for contractors who are knowledgeable about waterwise landscaping and low-volume irrigation techniques. Contractors who dont bone up on these subjects are really missing the boat.
Low volume basics
Drip, low volume, and micro irrigation are words that are sometimes used interchangeably. All refer to irrigation systems that deliver a low flow of water at low pressure at or nearthe root zone of plants. Low-volume irrigation actually consists of a variety of different systems that can be used together or separately in a given landscape. Each system has its own array of emitters or micro sprays that can tailor water delivery to the needs of a specific plant or planting area.
Drip systems bring water directly to an individual plant or small group of plants through flexible tubing. A variety of emission devices with different flow rates allow for the delivery of different volumes of water to each plant in the same run time.
In-line drip tubing or drip tape is designed to uniformly wet a larger area where plants are not as widely spaced. Emitters are molded directly into tubing at set intervals. The tubing is buried just below the soil or beneath mulch. Although it wets a larger area like overhead watering, water is delivered at a much slower rate, and less is lost to runoff and evaporation.
Micro sprays and micro sprinklers are another variety of lowvolume irrigation devices that are appropriate for dense planting areas. Water is delivered just above the ground through several small spray jets or sprinklers connected by flexible tubing. Because water is delivered slowly at low pressure, micro sprays and micro sprinklers allow for much deeper watering with minimal runoff. And because sprinklers and sprays cover a wide variety of patterns and diameters, its easy to design flexible systems that cover narrow, curving beds without wasting water on adjacent areas.
Flexibility is one of the great strengths of all low-volume systems. Different systems can be used within the same landscape, and can even be used in conjunction with traditional overhead systems. In recent years, there has been increased interest in retrofitting traditional sprinkler systems to low-volume systems. With the new rebate programs, this trend will only grow.
Reducing the learning curve
In the past, some contractors have steered away from working with low-volume irrigation unless it was forced on them by watering restrictions. ?Drip is a little different,? says Heenan. ?It takes a little more planning. After all, it is easier to cover a large area with a conventional sprinkler, but then, where is the conservation advantage??
While it may take more planning at first, many contractors point out that the installation itself can be a tremendous time saver. As with any new service, the learning curve shrinks and planning becomes easier with each project. ?The great thing about micro irrigation is that it?s so simple and so easy to learn,? says Thayer. ?It?s basically a lot of common sense.?
As they recognize the financial rewards of installing drip? rewards for themselves as well as their customers?more contractors are jumping into drip than ever before. Fortunately it?s never been as easy as it is now. ?Low-volume irrigation got its start with the agriculture industry,? says Komara. ?In the past, landscape contractors had to rely on ?dragover? products and adapt them to landscape applications. Now, there are many more products designed specifically for landscaping.?
Manufacturers are also creating products and systems that are designed to be especially easy to learn and use. Many make retrofit kits. ?The retrofit option is a very easy way to get started with lowvolume irrigation,? says LeAnne Pyle, marketing coordinator for DIG. ?You can convert one section of a sprinkler system over to drip, see how you like it, and gain experience with it on a small scale.? Customers who reap the benefits will quickly help you spread the word about this option.
?We offer kits to contractors to help them get used to working with micro irrigation,? says Jennifer Waxman of Antelco Corporation, based in Longwood, Florida. ?They can either use a sprinkler conversion kit, or one that works off a regular water source. It takes about thirty minutes to install. After that, they realize how easy it is. From there, they might attend a low-volume workshop for more indepth training. There are many good ones put on by distributors or water districts.?
Agrifim, based in Fresno, California, has launched a new concept called Simple Drip, which was created to take the guesswork out of installing high functioning drip tube systems. It features a limited collection of products that have been carefully selected and designed to work well together.
?The products have been selected for simple design, easy installation, and low maintenance,? says Dean Parrish, product manager for Agrifim. ?The line uses one size tubing, one dripper size, and one spacing. We also selected a very forgiving dripper to ensure low maintenance and fewer callbacks for the contractor,? says Parrish.
In addition to the system components, it includes a concise and expertly written guide that takes contractors step by step through the process and shows them how using drip can be more profitable for their company.
These products can be pruchased individually or together in one prepackaged unit called ?Drip-In-ABox.? Each box will irrigate a 300-square-foot space. While the products were originally designed for contractors with relatively little experience, the company has been pleasantly surprised by the feedback they?ve received from experienced contractors as well.
Not only are new products taking the perplexity out of installing drip, now information about design, product selection, installation, and maintenance is readily available. ?One of the most valuable places to start is the Internet,? says Heenan. ?Articles, studies, and papers are easy to find. Most drip manufacturers understand the need for education and they support their products with web sites filled with specifications and installation diagrams.
Manufacturers offer support by phone or in person. Most have someone on hand with technical experience in the landscape field,? says Komara. ?Trade shows are also an excellent way to get a look at different manufacturers and speak with them about their products. If you want us to come out there and show your guys how to do it, well do that too.
According to Komara, manufacturers have a big stake in educating contractors to use drip effectively. There are three main components to a successful system, says Komara. These are system design, system installation, and product design. When all of these are strong, a system will perform well. But if one of these components is missing, the system is destined to fail.
These failures can give low-volume irrigation a bad reputation. Sometimes during a drought or other high pressure situation, youll have a lot of inexperienced contractors putting these systems into the ground, says Komara. If hey don?t use the right product (for example, if they use a home center product instead of a professional grade product), the system is likely to fail. This leaves a black mark on drip irrigation. We work closely with municipalities to help them understand this so they can avoi any knee-jerk reaction that might come from a situation such as this.
One thing is crystal clear: when Circle 199 on Reader Response Card they are designed and installed correctly, low-volume irrigation systems are a win, win, win solution to a challenging problem. We have got to start conserving water when we irrigate, says Thayer. We just don?t need to throw that much water on a lot of our plant material. With low-volume irrigation we have a lot more control.