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Controllers: The Brain of an Irrigation System

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Of all yard care tasks, watering is the most misunderstood. "Overwatering is probably one of the largest issues we face in the industry," says Phil Burkart, vice president of The Toro Company and general manager of the irrigation division, in Riverside, California. "Homeowners and users don't know the optimum amount of water a plant needs. If a plant or lawn is stressed or brown, the homeowner will have a tendency to over-water."

2_3.jpg"If a little is good, a lot is better," is an old adage that certainly holds no water here. Pun intended. Lawns, flowers, trees, shrubs -- we have a tendency to over-water all of them. An estimated 30% of all water used to irrigate the landscape is not necessary and wasted. Unfortunately, too many people rely on guesswork when watering their lawns and gardens. Studies in Denver, Colorado, show the average single family home uses 45% more water than lawns really need. Inefficient watering costs time, money and energy.

Perhaps nothing is as important to our business as water. The beauty of the outdoors that surrounds us is more vital to our survival than we realize. Whether lawns, flowers, vines, trees, or shrubs, these living, breathing things contribute to our quality of life. They clean the air and environment, providing fresh oxygen. They have a calming effect and can soothe our souls. They provide shade and cool us from the sun. They provide beautiful and safe areas for our children.

So how do we protect our landscapes while conserving water? A good place to start is with controllers. Controllers are simply clocks that send an electrical impulse to the valve to tell it when to turn the water on and off at a specified time. This timing device allows you to schedule how long and how often you water each section of your lawn or garden. The original controllers were hydraulically operated. Then they went to mechanical, then electromechanical and in the 1980s a solid-state controller was introduced, followed by the hybrids (partially mechanical and partially electronic). Now they're mostly electronic, in terms of construction.

During the building boom of the late 1940s and '50s, suburbia came into being, bringing housing tracts and shopping centers with it. Office buildings followed shortly thereafter. Irrigation was installed on commercial properties and electromechanical controllers gained acceptance.

Irrigation for the residential market came later, especially in the Sunbelt and western states, where the climate is semi-arid. In those days, irrigation was installed with a manual valve that was used to turn the water on and off. A manual irrigation system presented another problem; the homeowner would turn the system on and then get sidetracked, only to realize an hour or more later that the water was still on! It wasn't until the early 1960s when homeowners embraced electromechanical controllers.

1_3.jpgThe original intent of controllers was mostly as a convenience factor. "It's like garage door openers," said George Alexanian, Alex-Tronix, Fresno, California. "How many homes still have manual garage doors?"

Today's controller is the brain of an irrigation system. "It can be something as simple as telling the valves when to turn on and off, as programmed by the user," said Burkart. "Or it can be something fairly sophisticated, like a Smart Controller or the central control systems that can take weather data and automatically calculate how long each station is supposed to run. It's the central nervous system or the brain of the entire irrigation system." Solid state controllers made their wau into the irrigation markets when Buckner introduced their KCS unit, a central controller, in 1978. In the early 1980s, Irritrol was the first company to introduce a solid state controller for the residential market, and almost immediately thereafter a new start-up company, Rain Master, came out with their product for the commercial market. It didn't take long for the rest of the industry to follow.

By the late '80s every manufacturer in the country was producing solid-state controllers in one form or another. Although revolutionary in design and function, these first generation units had some problems. Back then, the circuit boards were hand-soldered and some of the connections would loosen up, causing the controller to fail later on. They were also highly susceptible to lightening strikes.

As the years progressed, so did the technology. Controllers became digital and more bells and whistles were added periodically. "Like other technologies, controllers have evolved," said Alexanian, "not nearly as fast as computers, but they are progressing." Although the technology has become more abundant, the main function of the controller remains the same -- basically, to turn the water on and off. However, because there is more that goes into the landscape in addition to water -- the physics of the turf, soil, greenery, weather conditions, climate, etc. -- all factors that have to be taken into account, controllers now offer many features that weren't previously available.

Conventional vs. smart controllers

As controllers went from electromechanical to solid-state, they had more flexibility to add additional tasks. By today's standards, a conventional controller is simple to program. It does not have ET capability. On some conventional models you can add rain and moisture sensing devices, as well as remote controls. You can manually adjust them for weather conditions and seasons. In many cases, these controllers have a number of programs and start times.

ET, or smart controllers, are the newest innovation in controllers today. ET stands for EvapoTranspiration. Simply put, it is the amount of water that evaporates from the soil plus the amount of water that transpires through the leaves of the plants. Smart controllers can calculate the amount of water lost through ET using weather data collected from weather stations, or from historical ET data or satellite.

Smart controllers can connect to satellites or weather stations that monitor the local weather. These weather stations provide a wealth of data. They can be connected to a rain-sensing device that won't allow the valve to open when it rains. There are controllers that work with ground moisture-sensing monitors that detect the amount of water in the ground, and a slew of other tools that can be employed to ensure that the optimum amount of water is being applied as needed. Some controllers work from a personal computer or Palm Pilot; others can be used through the internet.

Some controllers can calculate how often and how much water to put down, others can supply reports for good water management and water audits.

Controllers have taken on a life of their own. With a myriad of controllers that exist on the market today -- from hardwired models to two-wire, to battery operated and solar operated types -- there is a wide variety to choose from.

By intelligently applying optimal amounts of moisture for plant health and appearance, smart controllers save water, time and money. They use scheduling software to optimize irrigation with site-specific watering based on soil type, slope, sun, shade, etc. The software downloads daily weather data from weather satellites, providing accuracy without cost and maintenance issues. These controllers have been proven to reduce water usage and runoff in residential- use studies.

I recently attended a symposium on water use and conservation, hosted by The Toro Company in Riverside, California, and I have to be honest in saying that I was shocked with some of what I heard. I've always known that water was an issue, and that every day our fresh water supply is drying up. Not until this seminar did I realize how dire the situation truly is.

To put things in perspective, I was having a conversation with a high-ranking official with the EPA; he asked me not to quote him on this, but gave me permission to print what he told me: "It's a strange time we live in. With oil and gas and war and economics and global warming and deforestation -- it's all scary stuff. But I'll tell you, oil doesn't scare me, or the impending gas shortages. I'm not bothered by modern economics. Global warming and melting icecaps are a major threat to all of mankind. These are all scary things. But I'll tell you the truth, what really scares me is the fact that, in our lifetime, we may see our supply of fresh water dry up."

Water is a scarce commodity and will continue to become scarcer in the United States. With a little care and prior planning, water can be conserved when used for home plantings.

3_1.jpgThe EPA has developed the WaterSense label program, much like the Energy Saver program, to get property owners to recognize products that qualify as water-saving devices. Manufacturers make every effort to get their products to qualify for the WaterSense label. Even greater pressure is coming from the State of California -- by 2012, all irrigation controllers sold and installed in the state must have smart water technology.

Water runoff is wasted water and is of concern to these governing bodies. Water that is not absorbed runs down the driveway or sidewalk, into the gutters and literally down the drain. It carries with it certain herbicides, pesticides and fertilizers that go into your water supply and contaminate it. "Water conservation and avoiding contamination go hand in hand," said Alexanian. "If you're using less water, there will be less water runoff, resulting in less contamination."

Quite a few cities and municipalities have issued water restrictions. If you tell a homeowner that he can only water every third day, on that third day he's gonna dump a bunch of water on his lawn to make up for the days he missed. That's going to be more water than the soil can absorb, which leads to dangerous runoff.

"Runoff is dangerous because it also leaches chemicals and fertilizers from the soil," said Burkart. "t causes erosion, damage to hardscapes like sidewalks, patios and streets. It also contributes to pollution. Basically, it picks up anything in its path and carries it into streams, water channels, the ocean or wherever else."

The water districts in California now have rebate programs for smart controllers; some offer 100% rebate while others are offering 50% back. Every district has its own mandates and rebate programs. I don't think it will be long before other states follow.

The future for controllers will be interesting, based on changing weather and strained water supplies. They will be less expensive, smarter and easier to use. "They need to be simple to use," explains Alexanian. "If you don't understand it or you can't program it correctly, then it's not going to do what it was designed to do. What good is that? It needs to be as simple as possible and as conventional as possible."

The controller technology that has historically been used on large scale systems is becoming available for the residential market. As demand increases, costs will come down. The focus over the next few years will be on easy-to-use smart controllers that are affordable for the homeowner.

 
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