Irrigation Trends

Keeling Company
There are some basic trends that are prevailing in the golf irrigation industry. HDPE pipe systems, irrigation auditing and soil moisture sensors are a few trends discussed here. Courses are mindful of the renovation cost associated with irrigation and want the most for the dollars spent.

HDPE (High Density Polyethylene) pipe

Our industry has seen an insurgence of courses bidding HDPE (High Density Polyethylene) pipe versus traditional PVC piping systems. What has changed? Well, price. The cost of HDPE has traditionally been 20-25 percent more in overall costs. Today that cost is more in line with 8 percent more than PVC. Courses are seeing the advantage of HDPE as a higher return on investment. HDPE pipe can handle more challenging installations with rock and extreme elevations. Irrigation designers must deal with the reduced flow capability due to the increased inner wall thickness of HDPE pipe. The HDPE manufacturers want courses to use all fused connections, or in other words a “pure HDPE system.” A true 100 percent HDPE project with HDPE valves and all fused lateral connections is cost prohibitive at this point in the industry. So, most systems that are being installed at this time use the best the market has to offer at the best price. Flanged ductile valves, compression lateral connections and compression head tees seem to be what the market is accepting as the standard. The most pipe companies that manufacture HDPE pipe are offering a 25-year limited warranty on their product. One must understand that HDPE pipe is classified with a wall thickness/pressure rating. This rating is given what they call (DR) rating. Most of the courses that are installing HDPE use DR 15.5 (130 psi-rated) pipe. On courses that need to run at higher pressures, they will decide to increase wall thickness to DR 13.5 (160 psi-rated pipe). Keep in mind as the wall thickness increases the flow capacity of the pipe decreases. The fact is HDPE pipe is not going away and many customers feel that the product can handle more abuse than PVC for the life of the irrigation system. The fears of the past about HDPE are waning. The OD of the pipe allows you to use traditional mechanical joints fittings for repair.

Golf irrigation auditing

Irrigation auditing is not a new concept in the horticulture field. Golf irrigation auditing however is fairly new, and as more consultants and manufacture reps learn the how to properly audit a course, the trend will continue to increase. Irrigation consultants use these tools to build their case for improper coverage in latent irrigation systems. Auditing irrigation is focused around the DU (Distribution Uniformity) or how well the sprinkler is covering an area, i.e. a green, fairway, etc. Rain is 100 percent (DU). Most manufactures of irrigation sprinklers can maintain values from 70 percent to 89 percent (DU). Another important component of auditing is determining the (SC) value or scheduling coefficient. The (SC) is the multiplier you have to apply to station run times to reach “perfect irrigation” in a particular area. The audit shows a course on paper what it already knows. These values can be used to develop a plan to eliminate water waste, reduce energy costs and increase playability. If the course has low DU values and high SC values, more than likely hours of man power are used to hand-water the greens. If you are spending hours dragging hoses hand-watering, then what is the purpose of having an automated irrigation system? Superintendents are using these reports to cost-justify irrigation renovations to their boards and owners today.

Soil sensors

Many manufactures are spending lots of energy and time to convince today’s superintendent to install soil sensors on their course. Sensors are not new and have been used for years in agriculture, proven in the cotton and citrus industries to increase yields and manage salts in poorer soils. Sensors today have software components to graphically show managers up-to-the-minute changes in soil profiles. Sensors can interface directly to your irrigation software. The software systems available today can use sensor inputs to override irrigation cycles and change on the fly based on preset parameters you specify. All sensors are not the same. Some sensors have a pre-determined life cycle and will have to be dug up and replaced. Most all sensors give you temp, pH, and relative moisture. There is some real validity to having sensors in areas that use reclaimed water and deal with salt in the green profile. The cost of sensors has come down dramatically. Until water usage laws change requiring this type of management these tools may only be seen on “high end” courses.