Here are some excerpts from a recent Golf Industry Column of mine:
When looking at the cost benefit ratio of infrastructure, there is little question that upgrading your irrigation system often pencils out as the best investment you can make. And, the numbers continue to get better. The irrigation industry spent its formative years working to let superintendents irrigate more turf more reliably. But with water restrictions proposed or reality in many areas, irrigation companies focused effort on reducing total irrigation needs.
The newest generation of irrigation systems offer substantial reliability upgrades with better gear drives, solenoids and grit resistance from their predecessors. More importantly, new sprinklers offer substantial cost savings in water and electricity use. The advances are so broad, that any course with a system over ten years old should consider some new components or possibly and entirely new system. If your system is 20 years old, it’s nearly certain that a new system will be worthwhile.
Improvements have come in sprinklers, control systems and designs that allow laser like precision in applications. The newest generation of sprinklers has distribution uniformity of 88%, versus 67% or less a few years ago. DU is a measure of uniform water application within a sprinklers coverage area, with 100% being perfectly even application. At 67%, you need to run the system 1.5 times that required to assure adequate coverage everywhere. (1/.6666 = 1.50) At 88%, additional running time is reduced to about 14%. Thus, simply replacing worn out sprinklers may offer water and electrical savings of 23%.
Some courses have experienced another 23% water savings by installing a new system designed for “precision application.” Irrigation designers know that more sprinklers equals less water usage. Tighter spacing increases DU, and fights wind effects. Using back to back part circle heads - once thought to be a luxury between greens and surrounds – is now used commonly to increase control differential for fairways and roughs. Using part circles on the border between turf and native areas eliminates unnecessary irrigation of native areas.
New irrigation system designs also focus more on control flexibility. This allows the superintendent to fine tune the system to irrigate different micro climates, such as hill and valley, shade and sun, much better than designs a decade ago, which focused on minimizing pipe and wire. Better control not only reduces water use, it reduces annoying wet or dry spots enhancing both turf health and play quality.
Irrigation control no longer requires guesswork and systems never have to run while it’s raining. Newer central controllers are “smarter” and use real time evaluation and data from past experience to constantly and intelligently adjust, cancel, pause and/or resume irrigation programming in response to changes in temperature, wind and precipitation and ET. Central control systems can monitor system flow to keep pipes running near capacity. This shortens watering time, saves water and energy, reduces pipe and pump wear, and completes watering sooner, allowing earlier mowing to beat the crowd.
New “Wireless Soil Monitoring Systems” which allow superintendents to determine irrigation need on actual on soil moisture, salinity, and temperature measurements, rather than computer calculations of ET, show great promise for further water savings. Naturally, location of these devices in representative micro climates makes them the most effective.
In one instance, the superintendent has documented 46% water savings on a per acre basis, by after installing a new system based on modern components and precision design. Some clubs use water savings to water more acreage and improve turf, others choose the cost savings of using less water, and a few use new systems simply to survive newly imposed water restrictions. I recently proposed a “precision watering” system for a course that will eventually add nine holes to avoid the cost of rebuilding their supply line.
Precision systems do cost more up front. Irrigation consultant Terry Little of Aqua Engineering in Ft. Collins, CO notes, “While long term savings will no doubt offset up front expense, in the current economy, many courses still opt for less expensive systems. Like many irrigation innovations, the new technology seems more common in the west, where water needs are often most critical. But, it works everywhere.”