Maintenance tips can improve irrigation

An irrigation system's overall efficiency is directly related to how well its parts are maintained.  If the system isn’t properly cared for, water waste and inferior appearance of greens and fairways are a sure bet.  However, course irrigation system maintenance is easy if superintendents are diligent in inspecting equipment and carefully following the correct steps for equipment needing repair. 

To ensure a quality golf experience for their players and optimal water efficiency, golf maintenance professionals can follow a few easy steps to keep their courses looking their best.

Tip #1: Ensure Proper Rotor Maintenance
Though they are designed to be nearly maintenance-free, today's rotors are an essential part of many irrigation systems and, therefore, should receive a dose of seasonal "TLC" to ensure proper operation.  When inspecting rotors, golf maintenance professionals should check each rotor for proper arc adjustment, thatch build up, proper rotation, worn nozzles and worn seals.  Occasionally, cracked cases and clogged screens can be found.  Most of these are simple to detect and fix but it does require professionals spending some time observing each rotor while it is operating to ensure that each one is working properly.

• Arc Adjustment – Make sure that each part-circle rotor moves completely through its properly adjusted arc pattern, which can sometimes be altered by golfers adjusting the spray or by vandals.  If the arc requires modification, readjust it according to the manufacturer’s instructions.
• Thatch Build Up – As turf grows, it develops thatch.  Thatch is partially decomposed organic material between the grass blade and the soil.  If the grass and thatch interferes with the water stream from the nozzle, it may need to be removed and thinned.  In older systems, it may be necessary to dig up the rotor, attach a riser and physically raise the height of the rotor.
• Rotation – As with arc adjustment, it's very important to observe each rotor in operation to ensure that it rotates.  If the rotor does not rotate, replace it with a comparable rotor and nozzle.
• Worn Nozzles – If a nozzle is worn, the rotor will have a reduced radius of throw and the water stream will appear "rough."  Worn nozzles usually occur in older systems or systems that have a dirty or gritty water source.  Replace worn nozzles with the manufacturer’s recommended nozzles.
• Worn Seals – A rotor with worn seals may display a flow of water between the rotor’s turret and the cap.  However, worn seals may only exhibit a slight weeping between the rotor turret and the cap.  In either case, the seal or the cap needs to be replaced.  Some manufacturer’s rotors allow the seal to be replaced.  When the seal is an integral part of the cap, the entire cap needs to be replaced.
• Cracked Case – A cracked case problem can be difficult to detect.  It will appear as an unusually wet area at the rotor.  This problem is usually found along a pathway and is the result of the rotor being run over by a cart or other vehicle.  Sometimes it is also the result of an improperly winterized system.  To correct the problem, the rotor must be removed and the case replaced.  However, there may be hidden damage to the rotor turret or the drive mechanism.  It may be more sensible to replace the entire rotor.

In northern climates, rotors should be physically inspected annually, usually at the beginning of the season.  In southern climates, an inspection should be performed at least twice a year. 

Tip #2: Fine-Tune Your Controller Program
Studies have shown that some courses are over-watered by 30 to 50 percent.  Golf maintenance professionals can conserve water and maintain a healthy, green course by using the “Triple-A” approach when maintaining their course’s irrigation control system:  Anticipate, Adjust and Achieve.

Anticipate - Forecast seasonal weather changes.  Obtain historical evapotransporation (ET) data for your area and mark your calendar.  Your central control system, almanacs and local agricultural resources can provide weather estimation on a daily, weekly or monthly basis.  Examine the data and set a monthly scheduling interval. 

The greatest water savings occurs from monthly programming modifications that include:

•  Knowing when to “peak up” – Don’t play catch-up with hot weather.  Prevention of dry spots and turf stress conserves more water than reacting too late.
•  Knowing when to “dip down” – Likewise, anticipate cooler weather to avoid overwatering.
•  Creating winter and summer schedules – Set start and run times with future water budget (percent) tuning in mind.  Generate the schedule during the off-season and keep notes from the previous season to revise the schedule as needed. 
• Labeling each zone – Note the station or zone information on a programming worksheet or card to eliminate confusion or scheduling conflicts when maintaining the system.  Most manufacturers supply these with the controller.  Make sure to also give copies of the zone worksheets to your grounds crew. 

Adjust - Modify the irrigation schedule using a “water budget,” which increases or decreases the run times of all stations on a program by a selected percentage, say zero to 300 percent, according to known peaks in temperature.   For example, the base schedule during summer may call for a 15-minute run time, twice a day in July.  Set the water budget to 80 percent on Sept. 1.  The cumulative run time will decrease to 24 minutes total.  The time spent to reprogram the controller only takes about one minute.  Let’s say the zone demands 15 gallons per minute.  You save 90 gallons a day on just that zone, not to mention the other stations on that program.  This is a fast, effective way to fine-tune the system, without the hassle of reprogramming every station. 

Water budgets can also help avoid turf stress, which is indicated by turf that appears flat, won’t rebound after stepping on it and may appear a little bluish in color.  Schedule similar zones (full sun to partial shade) on the same program.  In this way, water budget adjustments will have a positive effect on all turf areas without over-watering shrub zones.

Achieve - The benefits of fine-tuning course controllers are wide-ranging with water conservation being the most important advantage.  Customers also appreciate the detailed scheduling that the well-programmed irrigation system provides for players.  It shows competence and consideration on the part of the golf course superintendent. 

Tip #3: Maintain the “Brains” of the Operation
To ensure that the irrigation system is efficiently running, take some time to ensure that controller parts are fully functioning:

• Wiring.  All controller wires should appear neatly routed and properly connected.  When winterizing the system, check to see if the common wire has been disconnected.  This prevents an unwanted signal from reaching the valves or pump start relay.  Reconnect the common wire to the correct position on the terminal strip.
• Cabinet.  Clean up any foreign debris from ants, rodents, snails or vines and seal the openings.  Moisture ruins circuit boards.  Check the door seal and lock the cabinet when finished.
• Battery.  Replace the controller’s backup battery as needed per manufacturer’s specifications
•  Grounding.  Earth ground should be 5 ohms or less.  Check connections and ground rod conductivity by using a “Meggar,” a tool designed specifically for this purpose.  Improperly grounded controllers may void the manufacturer’s warranty.
• Rain Sensor.  Check, clean, and adjust the external rain sensor.  “Enable” the controller to react to sensor input.

Rotor maintenance, controller fine-tuning and periodic maintenance are fairly simple by following a few steps.  The time spent inspecting the system and making minor adjustments and repairs will help an irrigation system perform well for many years.  Moreover, golf maintenance professionals’ efforts will not only ensure that their courses will remain healthy and beautiful, they will guarantee that their players remain satisfied with the results.

Jon Watson is a training services manager for Rain Bird Corporation.  With its rich history of manufacturing products that promote its Intelligent Use of Water™ philosophy, Rain Bird is pleased to offer its numerous “smart irrigation” products that help conserve water resources through efficient water use.