Larry Rodgers of Larry Rodgers Design Group designs irrigation systems for golf courses. About 20 years ago, when he designed a system for a course I was developing, I only began to learn about the complexities of golf course irrigation and the choices that exist. Now, as water becomes an even more precious resource and there is political pressure on golf to use water more efficiently, I reached out to Larry again to learn more about what advances have been made toward making golf more sensitive to the ever-growing water issues that exist.
First, I asked Rodgers what strategies he’s advising for more effective water usage. He said “1 strategy is to be sure the present source is sustainable in quantity and quality. A close second factor is that the existing system records must be current and accurate for everchanging conditioning.” Technology being a bigger and bigger issue, Rodgers says that during the past 15 years nozzle performance has been peaking at about 90 to 93% efficiency. Many advancements in the systems are for accessibility to mobile devices. He says: “The #1 question I hear is can I get this control in an app on my phone.”
With the cost of replacing irrigation systems growing quickly, Rodgers provides his clients options. He first advises an assessment of the system should be completed to determine the present and future needs of every system. The assessment should address the following items:
- age of the system
- the operational outcome of the system (cycling surges)
- a review of the design via GPS mapping of all the sprinklers
After the assessment is complete an action report and meeting should be completed to present an improvement roadmap for the facility based on the expectations. Rodgers observes that upper budget facilities may be considering more frequent improvements as the experience sought is expected to be similar based on price points of golf. Golfers paying $200 per round expect better conditions than they experience at a $50 per round facility. The condition of the Irrigation is one of the most important tools the golf course has for maintenance.
Extending the life of an irrigation system is critical to many courses given the cost of replacement. Rodgers advises “Quit beating the system up!” He suggests looking at longer operation periods. Does the course have to be irrigated in 5 hours? Can the window be extended to create less flow through the piping network? Pump station upgrade to Variable Frequency Drive control will reduce dramatic surge cycling. Find and fix those nagging leaks to reduce the pump cycling. Strive for 2 to 3 cycles per hour as the maximum pump start cycles.
Among the things I was most impressed with about Rodgers’ philosophy is his ability to understand and match technology with economics.
He says: “Finances are patron driven. A small budget facility can have wonderful greens, average fairways and poor rough playing conditions that their patrons are happy with. Each project needs to define what level of quality they are looking for. I have not met any ownership (or club leadership) that sit with a manager (or superintendent) to tell them my goal is to throw enough money at the operation to make your life utopic. The question needs to be what is the pain level acceptable for loss of revenue as the patrons will seek quality conditions when given a choice. The low end average cost of a current irrigation system is between $1.5 and 2.0 million dollars. If the goal is for the system to last 20 years the reserve funds needs to be propped up appropriately.”
Among the options and decisions to be made are:
1) Coverage: Consider whether more or less area should be under irrigation and the associated cost
2) What do the transition areas need to look like? Define limits of irrigation. A fully trimmed/hardlines part circle sprinkler system will cost more $ than an overthrow system,
3) Control system: The 2- wire central control type systems require less wire than the 24VAC conventional systems, understand that this decision is a 20 to 30 year relationship, change will be very expensive as many of the systems are not compatible with other manufactures. No more matching Toro sprinklers with Rain Bird field controllers.
4) Additions: If budgets are the driver consider if there is flexibility and if components can be added to the system as cash flow improves, an example would be allow for the course outside coverage to be trimmed out with part circle sprinklers.
5) Piping: Never compromise on mainline pipe sizing as larger mainline where velocities are 3 feet per second should last 50 to 100 years with modern mainline components (HDPE).
When I asked the differences between the more complex and simpler systems, Rodgers described them and shared some rules of thumb below:
“The spacing of the sprinklers will drive costs and efficiencies of the system. Never exceed 80’ spacing as the winds will destroy all efficiencies. 50 to 55 feet spacing is acceptable by today’s standards for a high demand level facility or course with a limited irrigation source . A system with 80’ spacing may have 8 sprinklers per acre of coverage as compared to a system with 55’ spacing will require 16 sprinklers per acre and if the cost is $2,500 per sprinkler you will see how a 100 acre golf course cost could go from $2.0 million to $4.0 million.”
When I asked about the specifics of retrofitting courses in areas with particular stress on water supply and usage, Rodgers offered the following:
“The biggest factor with design for high level golf in the southern USA is spacing and outside “trim” definitions. Usual spacing is 55 to 60 feet with individual sprinkler valve-in-head controls. This factor allows for 16 adjusting points for an acre as opposed to 8 control points (valve-in-head sprinklers) per acre found on a larger spaced facility. Trimming the coverage with part circle sprinklers on the turf edges will add 35% to the sprinkler counts. Additional considerations are how the source quality can be manipulated/improved, making water more accessible to the plant.“
One thing Rodgers emphasized is that an irrigation system is a series of components, including electronics, mechanicals and piping. While many, including the ASGCA, estimate a useful life of 20-30 years for an irrigation system, the electronics only have 6-10 years before they’re obsolete and parts become unavailable and outdated. Mechanicals (valves & heads) have about 15 years and need to be exercised at least 4 times per year and ideally once per month. Piping, if sized properly, can last up to 50 years, especially the modern HDPE piping.
Rodgers sees more problems in lateral lines and recommends examining those first and if needed replacing with at least 2″ piping, compared to main lines of 4″-24″.
Pumps are obviously a critical component of any irrigation system. Rodgers evaluates a course’s climatic conditions, the size of the area to be irrigated and how much time the course needs to be irrigated in recommending both the number of pumps and their size. While most quality pumps last 15+/- years, the electronics controlling those pumps can become obsolete much more quickly, say 5-7 years.
With respect to selection of turfgrass and irrigation, Rodgers advises his client to consider that water quality is a bigger factor when selecting turfgrass. He notes a big push for some of the Zoysia turf types to be used in high profile applications like greens. In cool season applications 20 years ago there was a push for the buffalo grasses, over the past 20 years we have found that the buffalo grasses require higher water volumes than anticipated to stay greener. He further suggests consulting with a knowledgeable agronomist in selecting turfgrass varieties.
Given the popularity of effluent water usage, Rodgers cautions that the Quantity and Quality of effluent must be investigated and monitored closely. Effluent quality is generally treated to eliminate fecal coliform levels and the methods can produce less desirable PH levels. Some treatment methods raise the PH of the water which can seal up the soil, including the dreaded Black Layer. The design impact on an effluent source need to be identified in the pumping system with a fertigation/chemigation system and some type of PH control in addition to higher level filtration.
In advising his clients on whether to choose Rainbird or Toro (or some other manufacturer’s system) Rodgers emphasizes that both are excellent companies with quality products and that a big part of that decision is the local dealer and their service. He also said that both companies will negotiate warranty length based on what equipment is purchased.
As Rodgers clearly illustrates, irrigation systems are not a simple issue. They require many informed decisions on the part of club ownership or leadership and there are several levels of information required. It’s not only an issue of cost, but also of continuing expense, water source and quality and a course’s economics and maybe most of all, expectations.