Landscape Architect Articles

LSMP Irrigation March 200403-01-04 | News

Retrofitting Irrigation Systems

According to Hunter Industries officials, a good, quality sprinkler can have a lifespan from 10-12 years if it is maintained properly. A sprinkler?EUR??,,????'???s lifespan is slightly lower than other pieces in the irrigation system primarily because sprinklers take on all of the dirty or reclaimed water in the irrigation system.

Landscape supervisors and maintenance professionals are cognizant of the fact that at some point over the life of a municipal irrigation system, upgrades to the systems and/or components of the system will be necessary.

The retrofit of an irrigation system may be required due to a malfunction in the system, or the upgrade may be needed due to changes in local laws concerning water conservation. Older systems may not be in the best working order when it comes to conserving water. This is due to several factors, including inferior technology used on these older systems compared to today?EUR??,,????'???s latest irrigation systems, and the fact that water demand is far greater today than in the past, as water supplies dwindle.

According to the Irrigation Association, the future of irrigation depends on maximizing irrigation efficiency. Retrofitting older systems is an essential part of achieving the highest possible efficiency. Irrigation Association data shows that advances in sprinkler-head design, controller hardware and software, and sensor/controller communication have enabled distribution uniformities to increase efficiency from the 60-percent range to more than 90 percent. Uniformity results from proper design and precision of the sprinkler and other application methods, such as drip/trickle and microspray irrigation.

Remote devices can be used to operate irrigation system controllers. Hunter Industries manufactures the $695 ICR remote control that has a range of two miles and is ideal for institutional settings. The $189 SRR kit has a range of 450 feet and is good for residential use.

Although retrofitting irrigation systems for water conservation purposes will save municipalities money on water costs, these savings could be eliminated if care is not taking before a retrofitting project begins.

Kevin Gordon, new product development manager (controllers/control systems) at Hunter Industries, said the first step in the retrofit process is to evaluate why the upgrade is needed.

?EUR??,,????'??Once you know the reasons why the upgrade is needed, you need to determine the steps to take for the retrofit,?EUR??,,????'?? he said. ?EUR??,,????'??You don?EUR??,,????'???t do it simply because you have extra money in your budget.?EUR??,,????'??

Gordon said it is best to look at the old system to decide if it fulfills the original design intent of the project.

If the irrigation system is not doing this, superintendents must then determine what is needed to get the system back to its design intent, and figure out the most cost effective way to proceed with an upgrade.

?EUR??,,????'??In control systems, if the wiring is good, it?EUR??,,????'???s pretty easy to retrofit the system,?EUR??,,????'?? he said. ?EUR??,,????'??Usually in these cases there is no digging involved.?EUR??,,????'??

Advanced Features

Manufacturers such as Hunter and Rain Master offer controllers with advanced features that are expandable. Maintenance professionals can add modules of four zones to many new controllers as needed. This allows municipalities to get the latest water-saving features with the ability to expand irrigation control as the landscape matures.

Another option available if an irrigation system has multiple controllers is central control. In this upgrade, stand-alone controllers are replaced with field satellites that can communicate with a central controller either by wire, phone line or radio. Landscape superintendents can adjust all the satellites at a computer in one location. Some systems allow users to call the central controller from their home phone or computer to make adjustments.

According to officials at Hunter Industries, sprinklers have changed significantly over the past 20-30 years. Today?EUR??,,????'???s sprinklers are more efficient in the area of water conservation, and many upgrades are done to accommodate more stringent conservation requirements.

A third option for landscape officials to consider is the use of hand-held remote controllers. These use radio transmitters and receivers to operate satellites within a certain distance. Two-person irrigation projects become single-person ones with a remote, and these are helpful for troubleshooting.

?EUR??,,????'??Selecting the best control package for need and budget is essential,?EUR??,,????'?? Gordon said. ?EUR??,,????'??Cost has a lot to do with the number of controllers used on a system and the extent of the system upgrade.?EUR??,,????'??

Gordon noted that costs vary greatly when it comes to upgrading controllers. It could cost a couple thousand dollars to change out electromechanical controllers to new digital controllers. On the other hand, municipalities could pay in the tens of thousands of dollars to upgrade to central controller systems with weather stations.

?EUR??,,????'??What the maintenance person wants, or what they think they want, may not solve their irrigation problems,?EUR??,,????'?? Gordon said. ?EUR??,,????'??It is best for landscape officials to consult with a professional who can supply them with upgrade options.?EUR??,,????'??

Gordon said today?EUR??,,????'???s digital controllers can last more than a decade, adding that typically, when it comes to upgrading controllers, the life of the product is not the determining factor, rather, it is the better technology present in newer products.

?EUR??,,????'??Twenty to 25 years ago, only electromechanical controllers were on the market. These products were robust but simple and water management was limited,?EUR??,,????'?? he said. ?EUR??,,????'??Many feature sets that you see today were not available back then. In addition, as the technology has evolved, prices have gone down, so you can buy controllers today at a fraction of the cost of 10 years ago.?EUR??,,????'??

Sprinkler Upgrades

Another aspect of the retrofit of irrigation systems is the replacement of sprinklers. Steve Hoveln, product manager of rotors at Hunter Industries, said care must be taken when replacing sprinklers.

?EUR??,,????'??Landscape officials must make sure that what is being installed is equal to the flow and radius of the system that is being removed,?EUR??,,????'?? he said. ?EUR??,,????'??If you have sprinklers that are spaced 40 feet apart, you need to replace them with other sprinklers that work best when spaced 40 feet apart.?EUR??,,????'??

Hoveln said maintenance professionals need to do their homework when preparing to replace sprinklers. Sprinklers operating at a lower pressure provide a greater radiance.

If the radiance is reduced, the sprinkler may be broken, which ultimately is an easy fix. Upgrades also may be desired if a new product comes on the market and the landscape supervisor believes that it would be cost effective and better for water conservation to replace all of the sprinkler heads with the newer models.

The Easy Fit Compression System by Rain Bird is comprised of three fittings, five adapters and a flush cap to make fitting tubing easier. The three fittings feature the company?EUR??,,????'???s patent pending Easy Fit design that accepts multiple sizes of tubing, from .630" to .710" outside diameter (16 mm to 18 mm). In addition, the system now includes five male- and female-threaded adapters that are attached to the ends of the compression fittings for increased flexibility and installation ease.

?EUR??,,????'??Sprinklers are much more efficient today than they were 20-30 years ago,?EUR??,,????'?? he said. ?EUR??,,????'??This is a great benefit to the water conservation effort.?EUR??,,????'??

Maintenance professionals who choose to replace sprinklers, should replace every head in the particular zone with the same model. If pressure or flow is reduced, adjust the flow control on the valves to increase flow. It is important to check to see that sprinklers still reach the area intended for their spacing without misting. A good test is to place catch cans throughout a zone and run the zone for 10 minutes. The depth of water in each catch can should be the same.

Hoveln said the expense to retrofitting sprinkler systems comes when a major renovation, such as moving pipes, is needed. Trenching and the labor necessary to move pipes will add to the landscape superintendent?EUR??,,????'???s budget.

?EUR??,,????'??Fortunately, in park systems, you are usually not going to change out the pipes,?EUR??,,????'?? he said. ?EUR??,,????'??Usually, in parks systems, you see more individual equipment renovation as opposed to entire systems being retrofitted.?EUR??,,????'??

The most cost-effective ?EUR??,,????'??retrofit?EUR??,,????'?? of an irrigation system is a regular maintenance schedule. The equipment used on an irrigation system can last years with proper maintenance. Hoveln noted that controllers have a lifespan of approximately 10-15 years, depending on their location, while valves also last from 10-15 years. Sprinklers, he said, have a slightly shorter lifespan at 10-12 years because they take on all of the dirty or reclaimed water. In addition, sprinklers are the most visible and accessible parts of the irrigation system.

When it comes to updating or modifying drip irrigation systems, landscape superintendents must determine the tubing that is in the ground and find a fitting that will match the tubing.

?EUR??,,????'??In these cases, a landscaper may need to carry a variety of parts or contact the distributor to order a fitting for each tube they come across,?EUR??,,????'?? said Susan Broyles, Rain Bird?EUR??,,????'???s product manager.

Rain Bird?EUR??,,????'???s Easy Fit Compression system is designed to alleviate this problem because this system can be used to accommodate fittings of various sizes.

?EUR??,,????'??Now it?EUR??,,????'???s possible to use the same compression fitting components for almost any project that involves drip irrigation,?EUR??,,????'?? Broyles said.

The new Easy Fit Compression System allows maximum flexibility by accommodating countless installation situations while parts inventory is minimized. These one-size-fits-all components allow landscape professionals and distributors to carry and use fewer parts, reducing inventory and freeing up shelf space.

–––––––––