Computerized Irrigation Controls: The Wave of the Future?

The future of irrigation system maintenance may not be here for most irrigation contractors, but it appears to be on its way.

Computerized central control systems have long served the golf industry as tools for simplifying the process of operating a large irrigation system with multiple stations and controllers spread out across a large property. Manufacturers of these systems are now working to adapt the existing technology for use in large scale commercial, municipal and possibly residential applications.

“The message manufacturers have been hearing from state and local agencies is that there’s more acreage to irrigate but less people to do it,” explained Dave Megeath, field engineering manager for Motorola’s radio network solutions group, Fair Oaks, Calif. “Now, we’re hearing that same message from contractors as well. They’re looking for improved operating efficiency, and that means being able to send and receive information as quickly as possible.”

SYSTEM SETUP. The key concept for these systems is that contractors don’t actually have to visit the site to monitor, program and maintain the irrigation system. The systems are designed to operate based on information collected by evapotranspiration gauges and a variety of environmental sensors, which constantly collect data such as soil moisture conditions, flow levels and weather factors. This data is communicated back to the centrally located computer, usually at the office of those responsible for system maintenance.

The maintenance contractor can then use this information to gain a clear picture of the irrigation needs of the entire site and can program the system accordingly. All of this takes place without ever leaving the office.

“Once the systems is set up, the contractor could conceivably never have to reprogram it for the plants’ irrigation needs,” mentioned Tom Gentile of Gentile.Murray Associates, Mission Viejo, Calif., manufacturer’s agents for Calsense. “The system will reprogram itself daily based on information from the evapotranspiration gauges.”

Having such increased capabilities obviously requires a central control system to be specially equipped. Users of a central control system will have to purchase and install a central computer with the operating software, a method of communication between the computer and the system, and some sort of “smart” controller or satellite controller at the system site, in addition to the standard irrigation system requirements.

Manufacturers admit that all of this equipment carries with it a price tag that currently eliminates the possibility of many contractors using these systems. “Depending on the system, contractors could spend anywhere between $15,000 and $30,000 for the office equipment and between $5,000 and $15,000 for the system in the field,” noted Megeath. The systems can essentially handle an irrigation system of any size, with the only limitation being the range of communication between the job site and the computer.

Matthew Piper, Valcon division manager, a division of Weather-matic, Dallas, Texas, offered comparable price estimations for installing such a system, but said contractors concerned about the expense should analyze it against the potential benefits. “There isn’t any one business model for how contractors can sell this service right now,” he admitted, “but different contractors have found quite a few different ways to package this as a money saving tool for themselves and the client.”

Because of this added cost and the fact that these systems’ benefits are particularly apparent with larger sites, the market for computerized systems presently seems limited to municipal projects and large commercial accounts. “Cities and school districts are the primary users of these systems right now, because most residential and commercial projects haven’t shown the need for these systems at their current costs,” explained Dave Zoldoske, director at the Center for Irrigation Technology, California State University, Fresno, Calif.

“Any site with at least five or six controllers can justify a central system,” noted Gentile.

These additional costs can be particularly prohibitive if the contractor can’t convince the customer to actually purchase the equipment. “We had one county purchase the system for its parks department and hire the irrigation contractor on a retainer to maintain the system,” Megeath said. “Contractors are obviously concerned about being the owner of the equipment and having to go back out to the site and take the system out if they lose the contract after a year.”

SENSOR VALUES. Manufacturers strongly encourage contractors installing central systems to use various sensors along with the necessary evapotransipration gauges to maximize the system’s productivity. “The biggest advantage of these systems is having the power of a personal computer to manage water usage,” according to Rick Malkin, product manager for central control systems, Rain Bird Sales Inc., Tucson, Ariz. “The computer can interrogate the sensors and weather stations to track exactly how much moisture is being used from the soil, so when you do irrigate you only apply as much water as you need.

“Right now, too many contractors simply overirrigate to avoid having to go back out to the site and make the necessary adjustments,” he continued. “These systems automatically make the adjustments in run times so that’s not a problem.”

“It doesn’t matter how fancy we get with the technology if we don’t have the ability to communicate that information to the end user,” said Gentile.

Brad Wander, vice president, The Spencer Company, Houston, Texas, said the com-pany has installed two central systems and flow meters have proven valuable to them. “Our systems are programmed that if they detect excessive flow amounts, they monitor that flow level for 60 seconds,” he said. “If it remains too high then the system automatically shuts down the specific problem area.”

Wander explained that these sensors are important for communicating specific information back to the system operator. “The sensors are great for troubleshooting because they tell us exactly what the problem is and where it is in the system,” he said, noting that both systems they’ve installed have resulted in 20 percent to 30 percent reduction in water usage.

Jim Sieminski, vice president of engineering, Rain Master, Simi Valley, Calif, said contractors also enjoy maintenance benefits from central control systems. “Contractors maintaining irrigation systems need to be able to find out immediately when something breaks, and this can be nearly impossible when they’re responsible for heads and valves all over a city,” he explained. “Now, at the click of a button they can know what’s wrong and exactly where the problem is.”

This data from the sensors can then be collected by the computer to compile system evaluations and reports. “I can find out daily, weekly or monthly how much water is being used by a system and compare that to the water budget,” Wander added. “Seeing this information is important to the customers who have made the investment in the system and to potential customers who are considering buying a system.”

“These records can develop into a database to provide a history of the contractor has treated the site over the long term,” added Piper. “The information can also help them develop a strategic plan to lower their water usage by examining what practices are working well and what aren’t.”

CONTROLLER TYPES. Malkin explained that manufacturers are split between two different philosophies regarding the type of controllers installed with the system. “We use satellite controllers instead of stand-alone controllers to communicate with our central system,” Malkin said. “That means the system is completely controlled at the computer in the office. Other systems aren’t central control in this fashion. They’re more computer control with smart controllers in the field that allow technicians to access the system on site.”

Malkin admitted that some contractors may want to be able to access the system on site. “We believe that central control localizes the control of the system because a lot of contractors don’t want field technicians making adjustments in the system’s program,” he said. “There are pluses and minuses with each method.”

Wander said an additional difference bet-ween the two units is that having a micro-processor or smart controller on site means the system is constantly being evaluated. “With central command systems using satellite controllers, the system won’t react automatically to data from the sensors unless the system is on line,” he explained. “And if you want it on line all the time, you have to put in a dedicated modem line.”

CLEAR COMMUNICATION. Contractors have different options available to them for setting up the irrigation system to communicate with the computer. “The technology has become much more flexible,” noted Zoldoske. “Systems can operate over hard wire, radio or telephone now.”

Megeath said 95 percent of Motorola’s sales are radio-based systems, although he attributed part of that to the company’s focus on radio technology. “The benefits with radio systems are that you don’t have to worry about having extra cable in the ground and it simplifies retrofitting existing projects by eliminating the need to dig up existing plants or hardscapes,” he said.

Malkin said that Rain Bird can design a system to meet any type of communication needed, and each method has its own benefits. “The systems can communicate in so many ways now, including trunking radio, spread spectrum and telephone lines,” he explained. “Using the telephone lines is popular because then the phone company is responsible for taking care of the line for you, although hard wire systems offer the most secure communications. Radio communication is nice because it doesn’t require any trenching on site, but it does require the contractor to obtain proper FCC licensing. It all depends on the specific situation.”

Using telephone communications also expands the communication range for contractors. “I can dial up our system on my lap-top regardless of whether I’m at home in Texas or if I’m in California,” added Wander.

Most manufacturers also offer different combinations of the communication possibilities to best suit the specific site needs, and Megeath recommended contractors also consider tying in a paging system to their system. “It’s good to have a computer collecting all of the information, but it can be even better if the system sends an alphanumeric page out in the case any alarms are triggered while the operator is in the field,” he said.

TRAINING GAME. Unrelated computer technology has reportedly simplified the training needs for any system operators. “Operators don’t have to be real experienced working with computers to run one of these systems, although that does help,” noted Malkin. “I think we’ve seen the learning curve come down from three or four months to about one week to be comfortable running the sys-tem efficiently.”

Megeath noted installing central control systems will require the operating contractor have a thorough understanding of irrigation systems and proper design. “These systems highlight all of the areas where a system isn’t operating up to par,” he warned. “The operator needs to understand things like hydraulics and pressure problems. It can be a pain because of all the errors contractors will encounter, but it can also generate new business if the company bills system repairs as an extra cost.

CRYSTAL BALL. While no one’s ready at this point to predict that every irrigation system will operate on some type of central control in the future, manufacturers and contractors alike see a growing role in the industry for these systems, even for smaller projects.

“A lot of contractors managing residential or small commercial systems have the problem of staying on top of repairs,” noted Megeath. “Having a central system with flow sensors doesn’t entirely eliminate the need to check on sprinklers, but it probably eliminates 80 percent of that time with the information reporting. The only thing these sensors can’t do right now is tell the operator if a rotating head is actually rotating.”

“Our system allows users to program for microclimates,” noted Sieminski. “This means projects can be 10 miles apart but with the controllers on each site grouped into a microclimate and still be managed by one system.”

“The combination of smaller projects is really what we’re pushing for right now,” agreed Gentile. “This is perfect for someone handling multiple homeowners associations or similiar accounts.”

Piper said these systems will really pene-trate the residential and smaller commercial market when the cost issues are addressed by the manufacturers. “Contractors are telling us what they want in these systems, and they’re telling us that the costs for items like the controllers have to come down closer to a level of parity with what they would otherwise use on the job,” he said. “And they’re willing to make some trade-offs in terms of fewer features for a less expensive product.”

Wander said he’s finding potential customers more receptive to discussions about central control systems as water costs continue to rise. “Because water is a limited resource in our area, I think the trend towards using these systems for water use management will only continue,” he said. “Building managers and property owners are finally realizing how much more expensive irrigating is than it has to be

The author is Associate Editor of Lawn & Landscape magazine.