Landscape Architect Articles

LCN Inside Irrigation October, 200410-01-04 | News

Sprinkler Head Replacement
Yields Less Runoff, More Savings

La Jolla Country Club in San Diego County, Calif. includes close to 100 acres of Kikuya grass fairways and roughs and Creeping Bentgrass greens. The course was one of five that took part in a 2003 study that found switching to new sprinkler heads produced significant improvements in irrigation efficiency.

Golf courses are thirsty customers, consuming more than 476 billion gallons of water a year in the United States. That breaks down to an average of 88 million gallons per course?EUR??,,????'?????<

The sheer volume of golf course consumption means that even modest reductions can translate into big money savings and a reduction in strain on local water suppliers. Because many golf courses are located in or adjacent to urban areas, many use drinkable (potable) water?EUR??,,????'?????<

A recent study found that a relatively simple and obvious step?EUR??,,????'?????<

The study, published in 2003 by David Zoldoske of the Center for Irrigation Technology at California State University, Fresno, measured the changes in consumption when sprinkler heads were changed at five Southern California golf courses. The results varied by course–with at least one showing a water-use increase after the changes?EUR??,,????'?????<

Starting the Process

The first step in creating more uniform and efficient irrigation is to conduct an irrigation audit. This is a relatively simple task that involves setting out cups or buckets at regular intervals, running the irrigation system for a set time and measuring the results.

The trickiest and perhaps most important step is selecting replacement nozzles. This requires some knowledge of the products available and can be somewhat time-consuming, with superintendents needing to focus careful attention on water-deficient areas. Often it will be necessary to select sprinkler heads on a case-by-case basis. “Information was gathered in each case by the superintendent to select the ‘right’ nozzle to effectively improve sprinkler uniformity,” Zoldoske writes. “In some cases the superintendent started by replacing nozzles in the poorest coverage areas.”

Dr. James McAfee is a recognized expert with experience conducting irrigation audits, including on this Texas athletic field. Note water receptacles placed in a grid pattern on the field. Audit guidelines are available in the Irrigation Association’s Certified Golf Irrigation Auditor manual.

More information about performing sprinkler audits is contained in the Irrigation Association?EUR??,,????'?????<

The study found that the average investment required to upgrade a course’s nozzle system was around $12,000. The time to recoup that investment varied based on local water and energy costs but generally took about two years.

It is important to point out that precise cost estimates and estimates of time to recoup initial investment also depend on less easy-to-measure factors. For example, better irrigation uniformity can reduce the need to spot-water and can improve the appearance and playability of courses, resulting in additional dollar savings.

Drainage and Other Issues

There are some additional benefits that can result from more uniform irrigation. One is the reduction of runoff and deep percolation, both of which can carry fertilizers and pesticides into aquifers and to wastewater treatment plants. This is a serious issue as restrictive legislation has been proposed in several areas of the country when toxic chemicals show up in wastewater. “This could pose an additional hardship to the golf course superintendent if part of his/her chemical arsenal were lost due to poor irrigation system performance and management,” Zoldoske wrote.

One less obvious benefit to switching sprinkler heads is the opportunity to improve uniformity while reducing system pressure. For example, contemporary technology lets heads operate with “excellent uniformity,” at 55 psi, the report notes, while many systems currently operate at close to 85 psi. Depending on the amount of water and pump efficiency, managers can expect a savings of from $1,500 to close to $8,500 a year by lowering system pressure by 30 psi.

Conclusion

The study observed five California golf courses install more uniform and efficient sprinkler heads and note savings over the following year. When corrected for rainfall and evaporation, the average savings were close to 5.5 percent in water volume per 18-hole course.

Correspondent gains were seen in course appearance and playability, with superintendents noting significantly less need to spot-water?EUR??,,????'?????<The complete study text is available at https://cati.csufresno.edu/cit.