Turf & Rec

Features Agronomy
Water auditing will speak volumes about the state of an irrigation system


January 28, 2014
By Mike Jiggens


Topics

The importance of water auditing cannot be overstated. It will reveal how effectively an irrigation system is working, how much water is being put out, where it’s being distributed, and whether or not any maintenance or corrective action needs to be taken so as to maximize the efficient use of water.

Jeff Stauffer, superintendent at Mississauga, Ont.’s Credit Valley Golf Club, was keynote speaker at a water management and irrigation forum in November at Guelph’s Cutten Fields, promoting the benefits of irrigation auditing. Organizing the forum were first-year turfgrass management diploma students from the University of Guelph.

“Water audits are calibrating our irrigation systems,” he said, adding he firmly believes water auditing provides answers and data to ensure golf coures are doing what they can with less. It’s not just about applying water where needed when needed, but rather learning and knowing about how much is actually being applied during an irrigation cycle.

Most, if not all, irrigation cycles happen at night, Stauffer said.

Advertisement

“How many times do we run a full irrigation cycle in the daytime when we can watch it from start to finish? Not very often, if ever, because of golfers.”

Water auditing, therefore, provides a picture as to what happens at night when turf maintenance staff aren’t present.
Stauffer said irrigation auditing is useful for finding answers as to why wet or dry spots are consistently occurring, whether it’s the greens, tees, fairways or rough. For greens, irrigation is important from a playability standpoint. With the large volume of water needed to irrigate the expanse of fairways, water auditing may provide the opportunity to use less water, or possibly more if necessary.

Auditing has an impact on labour budgets, he said. If a golf course has identified numerous wet spots or dry spots, staff are being sent out to address them.

“Water auditing may help eliminate some of that.”

Irrigation schedules are then modified to meet the turf’s needs. The same irrigation cycles are not run on greens, tees and fairways. They are tweaked and adjusted for each area, depending on its individual need.

Historically, irrigation cycles have been on time-based schedules. When Stauffer first entered the industry, he said cycles were based on 10 minutes or increments thereof, and everything was based on time. Water auditing is not about time-based schedules, however, but rather volume.

He cited an example of completing a water audit on a green in which all irrigation heads are identified for that zone and data for the input material which should be going on into a central system around that zone for the heads is collected. Data which needs to be taken into account includes the number of heads, type of heads, nozzle size, pressure and spacing.

“Clearly define the components within that zone.”

The more one learn about the components of that zone, the better he is able to make decisions toward corrective action.
Questions requiring answers include:

• What is the static pressure at that zone?

• How much water is loaded and ready to go in the pipes?

• What’s the pressure coming out of that head?

• What is the comparison of the pressure actually in the field to that of the design?

Catch can testing must be done properly, Stauffer emphasized. Once data is collected from the catch can test, corrective action can begin.

At one time, the second green at Credit Valley always required hand watering to supplement irrigation. A water audit was conducted on the green, providing Stauffer with some key information. He said the distribution uniformity was only 45 per cent when the target number for a zone is at least 80 per cent. According to the Irrigation Association, 80 or higher is the objective.

“Now I knew why I was doing all this hand watering. Corrective actions were put in place.”

After auditing was done on all his greens, he realized he had been contributing to some of the disease issues on a couple of his putting surfaces because of inefficient irrigation.

Stauffer said that once he initiated the necessary corrective measures, disease issues on those particular greens were significantly reduced the following summer.

“It’s very important to understand and recognize how we may influence disease activity with our irrigation decisions.”

When spacing catch cans on his greens, Stauffer said he likes to place them 10 feet apart with no less than 60 cans per putting surface. He prefers to place as many as 72 cans in order to obtain more precise data. During the catch, runs times on three to five rotations of the heads should be defined.

Results of catch can testing conducted in the morning may not necessarily represent what is happening at night, he said.
The actual pressure going on should be compared to that of the design, Stauffer said, adding they won’t be the same. Pressures should be recorded—both static and operating—because the information will help for variation within the whole system. While moving around the property, certain zones that are lacking in pressure as compared with others can be identified, allowing an investigation into why that may be happening.

At Credit Valley, a zone was found in which the operating pressures weren’t optimum. It was found a faulty valve allowed less than 50 per cent of the intended water volume to get through.

“The key is to maximize the distribution uniformity.”

Stauffer said it is all about applying water as uniformly as possible and being efficient. Reaching those goals can be achieved only with the appropriate irrigation design and installation.

“Water auditing is a great method to ensure that the installer is putting the heads in on the proper spacing and on the proper design.”

He said it’s vital to ensure ongoing maintenance of irrigation systems which can cost between $500,000 and $2 million or more. Irrigation audits—sometimes referred to as irrigaiton calibrations—allow for a system to be continually evaluated to ensure greater accuracy when making irrigation decisions.

It’s also important to know of the infiltration rate and water movement in the soil, whether it’s sand, silt, loam or clay.
Similar to sprayers, irrigation systems must also be recalibrated. Data collection and information must always be updated because changes in delivery occur, whether it’s due to nozzle wear, a valve no longer operating properly or because of the person operating the computer.

“It’s important to recalibrate and revisit all these areas.”

Data collected six years ago may no longer be relevant. Stauffer said his goal at Credit Valley is to complete zones every three years.

“So our goal at the start of every year is to do a minimum of six greens and three fairways to update that data.”

Since irrigation auditing began at Credit Valley, the changes which have occurred within a zone have been “amazing,” Stauffer said.

“If there is a green that we’ve been visiting a little more frequently than we normally do (with a hose), then that’s a red flag if that zone needs to be recalibrated. We need to find out what’s going on in that zone that’s leading to the need for hoses.”

The golf course is realizing better playing conditions and healthier plants through water auditing, and have been finding fewer dry spots.

Money has been saved through reduced power usage, less pump station activity and decreased labour. Those who at one time were found manning hoses have been redirected to work in other key areas.

Once the rate of flow through the pipe system began to see a decrease, the club’s pump station became more efficient in pushing water through.

“By collecting data every three years, we know what the delivery of that water is per site.”

All information is input into Credit Valley’s central system so, when greens are set up, it is based one one-tenth of an inch, and central knows how much time to run each of those zones through.

Although water is regarded as a renewable resource, conserving it is critical, especially with further restrictions forthcoming, Stauffer said.

“We know they’re not going to get any easier.”

It’s all about managing golf course turf, or turf anywhere else, with less water.

Fertility, seeding and pesticide applications are all water-dependent, “and it could be argued that irrigation is the single most important tool for us in managing golf courses,” he said.

Irrigation, he added, is tied to difficult decisions superintendents must face on a regular basis, including how much, and where, when and way water is to be applied.

The use of water must be balanced to meet the expectations of members.

“We have to make sure we are responsibly using irrigation surrounding intensive maintenance practices that we’re putting in place to meet those expectations.”

In response to stepped up water conservation efforts, manufacturers have come forward with regard to heads, nozzles, valves, controllers, pump stations and sensors—the latter which Stauffer called one of the greatest advancements in recent years.

When managing golf course turf, he said the goal is to create the best playing surface while trying to promote and manage healthy turf. Water is fundamental toward that objective, and its role in managing turf should be thought about in terms of an integrated pest management program.

“IPM is not just about managing pests. It’s about promoting healthy turf to offset any pests. Water plays a fundamental key role in healthy turf.”

Whether it’s the operation of the irrigation system at night or with a hose in hand in the morning to handle hot spots, irrigation decisions promote healthy turf. Water is the key toward the plant’s function: its physiology, growth and life.

“We need to be very careful with the irrigation we’re using to ensure we’re doing everything for plant health on a positive—not so much negative—because water can influence the plant in a negative fashion.”

Water can directly influence pathogen activity, bringing on disease through improper usage. It can also impact insect activity which makes it directly a part of an IPM program, Stauffer said.

Playability is impacted by water. Overwatering will not permit firm and fast conditions. Although undewatering will contribute to firm and fast conditions, it will negatively affect plant health.

It’s all about finding the right balance, he said.

“It’s very important to understand the role that water plays in that.”