SportsTurf provides current, practical and technical content on issues relevant to sports turf managers, including facilities managers. Most readers are athletic field managers from the professional level through parks and recreation, universities.
Issue link: https://read.dmtmag.com/i/69161
Irrigation&Drainage SETTING UP THE IRRIGATION SCHEDULE The important first step in setting up a dripline irrigation program is to initially saturate the field so that it's like a sponge, said Willis. "We ran the irrigation for 24 hours straight until the field reached its saturation level. >> NETAFIM TECHLINE CV DRIPLINE was run in lateral rows with approximately 14 inches between each line of tubing. The tubing was set in place with an automated Vermeer insertion plow. head sprinklers. The comparison was done in May, a high usage month. Arapahoe Sports Park A is a 4.7-acre site irrigated with a traditional overhead sys- tem. The field used 437,000 gallons of water or 92,979 gallons per acre in May. Arapahoe Sports Park B, located nearby, is a 9.34-acre facility primarily irrigated with Netafim dripline (with overhead sprays in limited areas). During the same month Sports Park B used just 59,529 gal- lons per acre. Even though Sports Park B (with dripline) is twice the size of Sports Park A, it used just half the water. The district found there were lower maintenance costs as well. Because the sys- tem is not visible, mower damage and van- dalism are no longer problems and repair work is at a minimum, with no moving parts or heads to replace. Wind was another area concern, but with dripline there is no water loss on gusty days. "We've found that dripline also increases playability and safety on the fields. It soft- ens the soil and eliminates compaction, which is problematic with clay. Overhead sprays often compact a field even more, making it tough on injuries," said Rockne. INSTALLATION ON SPORTS FIELDS scape professional Chris Willis, president and founder of Colorado Total Mainte- nance, Inc., a landscape management firm Overseeing field conditions is land- 32 SportsTurf | June 2012 based in Denver. Willis has worked with Arapahoe Park "I have a tried-and-true method to de- termine when the right point is reached. I walk the field with shoes off and sink my heels in between the driplines to check the softness. Once we reach the right saturation point, we're good to go with the irrigation schedule." The Piney Creek Hollow irrigation pro- and Rec for 10 years and currently handles maintenance for the entire district. He has installed more than a dozen multi-use and baseball fields with dripline and has be- come an authority on sports field subsur- face irrigation. His expertise is well known and he has led regional seminars on dripline installation for designers and con- tractors. "Arapahoe's Piney Creek Hollow Park is one of our recent projects," he said. "It's a 4-acre athletic field with 16 zones controlled by a Hunter IMMS Central Control system. We installed the dripline in an 'open excavation method' by removing the top four inches of the soil, laying down the pipe and placing the dirt back on top. We ran the main supply header in the mid- dle of the field going east to west." The 17mm-wide dripline laterals were spaced 15 inches apart in 150-foot runs heading north and south. The irrigation coverage per zone was 5,500 square feet. Willis integrated a minimal nitrogen, plant-based organic compost into the soil to create a sandy/loamy surface. "This amendment has excellent water- holding capabilities. With dripline, the soil needs to retain the water to its maximum capacity for efficient coverage, yet be able to drain," he said. The site was then sodded with a hardy high-use athletic field mix from Graff Turf Farms. gram runs three times a week using a cycle and soak schedule. Each of the 16 zones operates for 8 hours in 6- to 8-minute cy- cles at .4 gph (gallons per hour). At the end of the 8-hour program, each zone has had 45 to 55 minutes of precipitation. Because the fields are so used and abused, the District has established on- going rejuvenation programs. Overseeding and topdressing are scheduled spring, sum- mer and fall and all fields are typically slice- aerated three times a season. Among the site challenges have been slope irrigation and the occasional dripline repair. "Even with built-in check valves, we've learned to adjust the scheduling to main- tain even distribution from top to bottom in sloped areas," said Willis. "As for repairs, sections of dripline have had to be replaced a few times, but it's been the coaches and parents at the 'root' of the problem. They'll pound volleyball net stakes or soccer goals into the ground, not knowing the irrigation lines are right be- neath." Lynn Cornell, manager of the Arapahoe Park and Recreation District, has been pleased with the success of the irrigation team. "They demonstrated that sports fields could be irrigated very efficiently with dripline yet still maintain playability. The District has reported significant savings, based on water bills," he said. "It's been a win-win for all teams in- volved in the project." ■ www.sportsturfonline.com