Why does golf course irrigation have a negative tone to it – almost as bad as a four-letter word in some circles? By weight, a turfgrass plant is more than 90 percent water. Water is essential to all life, turfgrass certainly no exception. Depending on your geographic location, irrigation is more critical in some regions than others, but we cannot deny the importance of a reliable, efficient irrigation system when our livelihood relies on maintaining healthy turf, day after day.
Why then is golf course irrigation as popular as a root canal? Is it the expense; the fact that it is primarily invisible, misinformation or lack of understanding?
Comparatively speaking, golf course improvements can range in price. New bunker sand and drainage $150,000 to $350,000; and rebuilding greens $250,000 to 500,000 on average. What do all of these have in common? Unlike the irrigation system, they are all highly visible and can be immediately appreciated by a member or daily-fee customer. The reward for hitting that clean shot out of a new bunker sand or sinking a 10-foot putt on new greens is immediate. Everyone benefits. When was the last time you saw a golfer jump up and down with joy because you have new sprinklers around your greens? It doesn’t happen. No, irrigation system upgrades and replacements are a different animal and should be approached as such.
Today’s irrigation systems can range from $750,000 to $3 million-plus for 18 holes and, in extreme cases, exceed $5 million. That kind of money will get you a lot of new bunkers and then some.
But how can you determine if a complete replacement is necessary? Rather than a complete replacement, there are many circumstances in which upgrades to the irrigation system can be money well-spent and lengthen the lifespan of the system.
Start with a thorough evaluation. This can be accomplished on your own, but you will get much greater results by contracting with an irrigation consulting service. Suppliers may offer a similar service, but you will not receive the same amount of detail and you are better off avoiding that route. There is a lack of credibility when a complimentary system evaluation provided by a supplier is presented to an owner or the green committee. An independent consultant’s evaluation is much more affordable than you think. And avoid hiring a consultant that is just providing a cookie-cutter form letter where they substitute photos from the last golf course they evaluated with photos from your course.
Here are a few main items to look for in a system evaluation:
- Pumping system and water supply. A very important piece to any irrigation system is the quality and quantity of the water supply. Understand what is available today and years into the future. As water demands continue to rise, it may be worthwhile to investigate receiving effluent water or capturing more runoff water to be used for irrigation. Determine the age, condition and life expectancy of the pumping system.
Pump station technology has come a long way in the past few years. It’s not that the technology is new, it’s the fact that it is finally being applied to pre-packaged pump stations for golf courses. Your golf course can benefit from the efficiency and intelligent monitoring capabilities available in today’s pump station controls. Remote connectivity with the pump station is much more reliable and affordable today.
If your golf course is supplied by a municipal water source, you may have a booster pump and backflow equipment. This equipment should also be evaluated, including the incoming pressure and flow from the municipal source. Over the years, changes may have occurred that you were not aware of.
- Hydraulic network. What is the age and condition of the pipe and fittings? What type and material are the fittings that were installed? There can be lots of variability here, ranging from coated steel fittings to galvanized and even asbestos cement pipe on older systems.
Understanding pipe size, the velocity of water through the system and both dynamic and static pressure at critical points in will tell you a lot. So many times, the first thing I hear is, “I have poor pressure over here and I can only run two sprinklers” or “I can only water this area when there are no sprinklers running on the rest of the course!” Well, that could be a pipe size issue or something more serious causing inadequate pressure.
Common with older systems is undersized pipe or lack of looped main line pipe to meet today’s conditioning demands. Are you documenting repairs you and your staff have made to the system over the years? Repeated equipment failures and their locations can tell you a lot about the system. Maybe you inherited a poor installation or maybe you are seeing premature failures of different components or fittings. Documenting the repairs will help you quantify the amount of time and material costs you and your staff have invested in keeping the existing system operating.
- Distribution System. Obviously, the sprinklers are an incredibly important part of the irrigation system. And golf courses can have a range of different types from valve in head to spray heads to short radius block rotors. Quality of uniformity is directly linked to spacing in the field for that specific nozzle and pressure. An important piece to an evaluation is understanding the sprinkler spacing and performance for all areas on your golf course.
Perform a water distribution audit with the assistance of a certified golf auditor. An audit or "catch can test" should be performed in several areas throughout the course. Select areas that are indicative of what you can expect on the rest of the course. The audit will produce several key data points that will give you real insight into how the sprinklers are performing including distribution uniformity as a percentage. Distribution uniformity, low quarter, is a factor of the average volume of the lowest 25 percent of the catch cans divided by the average volume of all the catch cans in the area being audited. A distribution uniformity less than 55 percent is not ideal and can be addressed even without changing the spacing. For comparison, mid-80s and higher is achievable with golf sprinklers and large spacing.
- Electrical/control system. Whether you have a satellite system or a two-wire system, the integrity of the conductors and splices is also very important to reliable operation. Understanding the material of the insulators and integrity of the splices can determine life expectancy. And I can't overemphasize the importance of documenting repairs – even wire repairs due to high-energy events like lightning or tree roots compromising a wire splice. Is the system properly grounded? I can’t tell you how many times I have come across earth grounds that failed years ago or are insufficient for the components they are meant to protect. Is there a central control computer, if so, what features does it have? What features is it lacking?
A thorough irrigation system evaluation never fails to expose deficiencies that you may not have been aware of and offer an explanation to persistent problems. The evaluation will also tell you what is salvageable if anything and you can determine life expectancy of the different components. Whether self-performing an evaluation or working with an irrigation consulting service, the evaluation process is an optimum time to prioritize your irrigation system needs with your maintenance practices and operating budget. Odds are if you are investing time and resources into a system evaluation, the system has been underperforming for years and the number of repairs continues to rise.
After prioritizing your needs, you can determine what upgrades will get you more bang for your buck. And keep in mind, some upgrades can be recycled if you do replace the entire system in the future. If a complete replacement is out of reach, there are improvements you can make that your golf course will benefit from and are affordable. Here are some ideas for cost-effective upgrades that will extend the life of your system.
- Sprinklers. Did you know that a sprinkler more than 3 percent out of level has a 10 to 15 percent reduction in distribution uniformity? Three percent doesn’t sound like a lot, but unlevel sprinklers can have an overwhelming effect on uniformity. Over time, sprinklers may settle or even sink with years of heavy topdressing. Leveling sprinklers is not as monumental a task as it sounds. You can prioritize your areas and work through the project systematically.
With any upgrade or replacement for that matter, I would recommend a thorough cost analysis prior to making an investment. You may find it is more cost-effective to hire a qualified contractor for the project rather than tie-up your staff.
Replace or correct nozzles. Nozzles wear over time, some more than others depending on your water quality. A nozzle change can improve uniformity as well. Here’s a tip: make sure the new nozzle is most suited for your spacing. There is software available that will determine the best nozzle and case pressure for your spacing. Do the nozzles in the sprinklers match the nozzles in the central control database? A database with as little as 5 percent of the nozzle flow incorrect can have an impact on your water window and pressure experienced while watering. A thorough inventory of the sprinkler nozzles and case pressure can be used to correct the database information. If your spacing is optimal, and when I say optimal, I mean uniform and equidistant for the area, you might consider an entire sprinkler change out.
Many other factors play in this decision. What is the life expectancy of the lateral lines and fittings? Are the lines sized adequately to irrigate within your desired water window? What size main line and sub-main line is feeding the laterals.
- Hydraulic system. Now this can be a big area. If you are experiencing mainline pipe and fitting failures at regular intervals, there may be more serious and extensive issues with the system. Managing water hammer or surge pressure is key with any irrigation design. Golf course systems are unique in that wide swings in flow are common and frequent, surges cannot be prevented but rather they are calculated in the design and managed by main line routing, pipe size, air relief valves and central control in more modern systems.
Depending on the age, size and life expectancy of your main lines, your system may be a candidate for a new system while reusing the PVC main lines. PVC has a life expectancy of 50-plus years with a good installation and design, so it’s the fittings and valves that may become the weak link. Soil type and water quality also play a part in the life span of fittings.
If your PVC main lines are gasket joined, of adequate size, have been reliable and they are less than 20 years old the potential, is there to utilize the existing mainline or at least a portion of them in the design of a new system? With careful investigation, the main lines may be able to be re-utilized and new lateral pipes, sprinklers and the control system can be replaced. The result is a new system in terms of reliability and improved efficiency at one-third of the price of a complete replacement. With HDPE systems becoming more and more prevalent in golf applications, I expect to see more HDPE pipes re-utilized and the sprinklers and controls being updated going into the future.
- Control/electrical system. Your course may still have a normally open system, commonly referred to as a “hydraulic tube system”. These systems are very difficult to maintain. And repair parts are almost non-existent. If this sounds familiar, you may already be looking at control system upgrades. Make sure you consider a two-wire system upgrade and not just satellites for replacement. In both cases, you must install new wire to replace the older hydraulic tubes, so it is worth comparing pros and cons of both before deciding.
Lastly, if you are without central control, there are several options to get into a low-cost central control from the manufacturers. Adding flow managed central control will help extend the life of your system even with older pipe by controlling the velocity of water in the system and better controlling surge pressures throughout the system. Again, this is another piece of equipment that could remain or be updated inexpensively to the latest software if you were to replace the entire system down the road. There are also a host of features available from most manufacturers that increase irrigation efficiency by making intelligent decisions during irrigation and giving the user more control over the system.
By prioritizing your needs and understanding the current system and life span, there are many affordable upgrades that can be made to an irrigation system that will extend the usefulness and improve efficiency. OK, now the hard part: How can I get my club to invest in these upgrades?
Ian Williams, CID, is a partner with Don Mahaffey at the irrigation design and consulting firm Green Irrigation Solutions.