Water conservation strategies for sports fields

Amarillo Independent School District in Texas recently installed a KISSS subsurface irrigation system beneath a newly renovated football field. The system conserves water by delivering it directly to the rootzone and reducing or eliminating evaporation and runoff.

Like people, turfgrass needs water; it can’t live without it. Of course, in sports field settings, water does far more than keep the grass alive. It helps keep grass healthy and ensures high-quality, safe playing conditions, so it’s not the kind of thing that sports field managers can do without. Still, many are finding ways to get the job done with less water.

Some groundskeepers have turned to new technologies to conserve water. Others are taking a lower-tech approach. Regardless, everyone emphasizes that the core principles of sound irrigation system design, proper operation and regular maintenance are important conservation strategies.

Amarillo Independent School District (ISD) in Texas is using technology to help cut water usage. The district, which boasts hundreds of sports fields spread out over 56 campuses, recently installed the Kapillary Irrigation Sub-Surface System (KISSS) on a football field. “Our goal was mainly water conservation,” says John Adams, Amarillo ISD’s grounds department foreman. “We live in drought here. We don’t really know anything else.”

Adams credits Larry Musser with PRZ International Sports Turf Consulting (based in Colorado Springs, Colo.) for telling him about subsurface irrigation and how it can save water and produce a quality playing surface. After learning more, Adams decided the concept was worth a try.

The KISSS underground system installed there delivers water directly to the rootzone, reducing or eliminating evaporation and runoff (not to mention water carried away by wind), which are inherent with overhead irrigation systems. The district’s grounds maintenance department was able to install the system in-house. “It was really pretty simple,” says Adams. “We plowed it in [the lines can also be laid out and then covered with soil], so it didn’t take nearly as long as I thought it would. We had five guys out there and we put it in the entire field in just two days.”

After the irrigation system was installed Adams and his team sprigged the field. “We sprigged right on top of it and we didn’t need to use any additional irrigation to get the grass going,” he reports. The system was installed this past May and has proven to work equally well as the grass has matured. There was one kink to work out, says Adams: “Our field looks fairly flat, but there’s actually 2 feet of fall to the west, and we put the header in on the west side instead of the east side, so we were pushing water uphill, and it would start dripping on the west side a lot faster than it would on the east end. It was taking almost five minutes to push water all the way to the east end,” he explains. “We moved the header to the east end, and now it takes less than one minute to get it to the west end; and it makes a big difference as to how water actually drips and how evenly it spreads out.”

Now, says Adams, the system is working great. It runs from a central control and flow sensors were installed, as well. “It’s pretty interesting to see the flow being so low,” marvels Adams. He estimates that the field is now using a little less than half the water it was using with an overhead irrigation system. “When you run rotors, you’re going to turn those on for 15 minutes or 20 minutes or 30 minutes. This system runs on a pulse. It will run maybe five times a day; part of our field runs for eight minutes and another part runs for 10 minutes and another runs for 12 minutes and another for 15 minutes.”

The subsurface irrigation system was used during grow-in, when sprigs were established on the newly renovated football field.

A fertigation system was installed as part of the new irrigation system, which is providing tremendous control over fertility. “That’s been a real plus,” Adams says. “We just trickle feed it and the grass is really responding.”

Otherwise, he notes, field maintenance practices haven’t been affected by the new irrigation system. “We even put our Rotadairon out there and tilled the field before we sprigged – just an inch deep or so,” he says. The lines are installed about 6 inches underground.

The field at Bowie Middle School was under renovation, so there was no concern about disturbing the playing surface with the installation. However, Adams was curious, so he ran the KISSS plow machine (which slices the turf and lays the material underground) on an adjacent, fully grassed field. “After I drove down the field, you really couldn’t even tell it had been done. All we did was just topdress that area a little bit.” He thinks the system could be installed on an existing field with minimal damage.

The field is now ready for play.

The district’s decision to install the system was timely, because water conservation is becoming a larger issue in the Amarillo area. “Conservation is very important. I think we’re way behind in this area, I really do. I think people are just staring to grasp how desperate we are for water in this area,” says Adams. He notes that there are complaints from the public when people see the school’s fields being irrigated. The subsurface irrigation system eliminates that problem.

Technology is also being used to conserve water at Summit Park in Chattanooga, Tenn. There, an eight-field softball complex that was built in 2009 is being irrigated with the assistance of soil moisture sensors. The system was designed by Michael Clark, president of Clark Irrigation Design and Consulting of Lavonia, Ga. “We wanted to put them in a position where they could manage their sports fields while using as little water as possible. It was the first sports field complex I had done where I used soil moisture sensors as the controlling tool,” Clark explains. “Since then I’ve used them more often in sports fields.”

The Summit softball irrigation system utilizes soil moisture sensors from Baseline Systems. The sensors are installed in the rootzone of the turf and wired to the controller via a two-wire-style communication system. “They can be set up two different ways. The first is using what’s known as a low-moisture threshold. That’s when you tell the system, ‘Unless the soil moisture drops to this low level, keep the irrigation system off and don’t let it run at all.’ Once the soil moisture reaches that level, the system operates. The other way you can go is to let the system operate on its normal schedule, but to only water to an upper threshold limit. It will run the first zone for as long as it takes to reach that level within the soil, and then it adjusts the run times of all the zones after that,” Clark explains.

While the decision between operating modes “really comes down to a sports field manager’s preference,” the former tends to be the more water conserving and common option, he adds. It also helps provide a little greater control over moisture levels. Clark says, “I’m an irrigation designer, but if I were a turf manager, I think I would want to dry the soil profile out some, promote some better root growth depth, and only run the irrigation system when I had to.”

While soil moisture sensors offer impressive technological control, that doesn’t mean human input is eliminated. Some training is required in order to use them properly. “There is a slight learning curve to figure out how to control the moisture sensors,” Clark says, pointing out that any automated system, whether it’s a soil moisture sensor or a weather-controlled system, requires an initial calibration. One good water conservation strategy, he advises, is to install the system and set a low threshold point. “If you start there and your turf is looking really good, then maybe you can lower that threshold a little and still keep that quality where you want it while using even less water,” he explains. It’s just a matter of tweaking the system until the optimum balance between good turf and maximum water savings is achieved.

After that, the system can pretty much run on its own, but regular checks for coverage and operation are critical for both turf health and water conservation. Clark adds, “It’s nothing new, but you need to make sure your distribution uniformity is the best you can get out of your sprinkler head.”

A special machine is used to “plow in” the subsurface irrigation system, allowing it to be installed even on existing fields.

The number of soil moisture sensors installed depends on a number of factors, including groundskeeper preference. At the Summit installation, the eight softball fields are laid out in three groupings and one sensor was installed in each group. Some sports field managers opt to put a sensor in each field. “The controller can handle up to 24 sensors, and they are not that expensive, so that’s certainly an option,” says Clark. “On the other hand, at a less intensively maintained soccer complex, where there may be many fields all on similar soil and all with the same climatic exposures, you can probably get by with one sensor.”

Clark notes that soil moisture sensors are being installed more and more in sports field settings. “There’s been some really good research, including by Dr. Michael Dukes at the University of Florida, showing how much water can be saved using soil moisture sensors as opposed to just a manually set irrigation controller. So there’s some pretty good science behind their water savings potential,” he states.

Another technology Clark is incorporating into his sports field irrigation system designs is flow sensors. “The flow sensor will talk to the irrigation controller, and, depending on your system, you can get a wide variety of information back about overflows or underflows. This then helps the sports field manager organize service to the system,” he explains. For example, the system might report that something broke on zone 3 during the night, so that zone was shut off. Getting quick input on system problems can help save significant amounts of water that otherwise would be wasted.

Soil moisture sensors and flow sensors can both be retrofitted to existing systems, but Clark points out that these systems are proprietary to specific manufacturers, so a new controller may need to be installed along with the sensors. “If you’re going to put in these sensors, they need the ability to ‘talk’ with the controller,” he says. “If you have a 20-year-old irrigation controller, it’s not going to have the ability to talk with those sensors.”

Beyond high-tech sensors and controllers, and routine system maintenance, there are other innovative methods for conserving water when irrigating sports fields. Duke University in Durham, N.C., for example, has set up cisterns to collect rainwater from campus rooftops. Once captured, the rainwater is used to irrigate various grounds and athletic fields. The school purchased two 4,000-gallon tanker trucks to transport the water to where it’s needed, including smaller cisterns that can feed the irrigation system at the school’s soccer/lacrosse stadium.

The effort to irrigate using stored rainwater began after a severe drought in 2007, and this strategy is employed when drought conditions revisit the area, explains Roger Conner, Duke’s grounds superintendent for facilities maintenance. “We currently have about 400,000 gallons worth of cisterns on campus to collect stormwater and condensate, and Duke is in the process of building a 6-acre pond that we’re going to be able to pull water from, as well,” Conner explains.

Duke is continually incorporating technology into the irrigation systems on the school’s 22 acres of athletic fields. For example, the irrigation system for the school’s newest practice field boasts a cutting-edge smart controller. “The smart controller is keyed into a weather station and can even send emails to us if there’s an unusual amount of water being used, which lets us know there’s probably been a break in the line or a head that’s not working properly,” says Conner.

As part of the NCAA, there are requirements regarding the conditioning of fields that can make water conservation more difficult, Conner points out. “We really try hard to conserve water as much as possible, particularly in drought conditions, so that we’re not overusing it,” he says. “We’re constantly watching our heads and checking them to make sure the water is all hitting the turf and not hitting any hard surfaces. Technologies are great, but they can’t replace manpower and day-to-day visual checks.”

Patrick White is a freelance writer and editor who is always on the lookout for interesting and unusual stories.