Landscape Architect Articles

2008 January LSMP Irrigation: Drainage Supports Synthetic Surfaces01-04-08 | News

Drainage Supports Synthetic Surfaces

By Tori L. Durliat, for LSMP

Varicore Multi-Flow drainage lines are arranged at a 45-degree angle to the slope of a FieldTurf soccer field being installed at Huntington Beach, Calif. Note the use of computerized laser survey equipment to ensure precision placement of the 12-inch polyethylene lines. The herringbone pattern of the drainage is visible in the photo. Any water flowing from the center of the field toward the sideline will cross a drainage line and be carried away. Photo by Erik Skindrud

Synthetic surfaces are extending play times for everything from horse racing to football. Their increased resiliency, however, rests on the drainage systems beneath them. Correctly-installed drainage lines ensure that water from heavy precipitation events won?EUR??,,????'???t undermine subsurfaces, leaving fields firm and playable (or raceable) when skies clear.

Whether it?EUR??,,????'???s horse racing, soccer, field hockey (or any of a dozen activities) athlete safety is a top priority. Like all playing fields, synthetic surfaces around the world are always looking to make their play surfaces safer and more consistent.

With conventional dirt tracks, water drains horizontally which can compromise the track?EUR??,,????'???s condition by allowing it to freeze in cold temperatures or become muddy after hard rains. These types of conditions could lead to a decrease in the number of starters, increase in the number of injuries and in the number of cancelled racing days ?EUR??,,????'??? all of which can contribute to unappealing wagering and reduced track attendance.

Some racetracks are turning to improved drainage and synthetic racing surfaces, like Polytrack, to help solve the problem.

Water flows off the racing surface into a total of 62 of these Nyloplast basins installed at 300-ft. intervals across the track.

Built in Layers

This particular surface is made up of a blend of fibers, recycled rubber and silica sand covered with a wax coating that allows water to flow vertically through the top surface to the sub layers below and helps avoid a freezing or inconsistent racetrack. The sublayers include porous macadam and dense aggregate rock that provide a solid foundation while the vertical drainage system carries water away from the track. Together they work to provide a safer, more consistent racing surface in comparison to conventional dirt tracks.

To date, three North America racing facilities have announced that they will install this type of track and drainage system. Keeneland, located in Lexington, Ky. was one of them.

In the heart of Kentucky?EUR??,,????'???s Bluegrass Region, this storied racetrack was originally built in the 1930s and has since played host to some of the greatest races in the history of the sport. Keeneland has also welcomed many notable people over the years, including Queen Elizabeth II, Former President George Bush Sr., The Princess Royal and Princess Anne of England.

Keeneland?EUR??,,????'???s existing dirt track was not having drainage problems. The reason the new vertical drainage system was installed was because it?EUR??,,????'???s a prerequisite to the Polytrack. One needs the other to function properly and the success of the final product is totally dependent on the two working in unison.

Keeneland Racetrack in Lexington, Ky. is completed and ready for the next big race in this view. It looks like a conventional sand surface, but the finished track is covered with a blend of fibers, shredded rubber and silica sand that has a special wax coating to let water flow vertically to the sublayers below. Photo courtesy of ADS

Installing the Project

The installation process was quite extensive and the deadlines tight. The project began in May and needed to be completed by the end of August ?EUR??,,????'??? in time for Keeneland?EUR??,,????'???s fall race meeting. Engineers and contractors were all under pressure and knew that if they were to complete this project on time, superior and versatile drainage products would have to be used.

The drainage system was constructed using ADS pipes and Nyloplast structures and basins. Engineers and contractors who worked on the project all stressed the fact that the success of this synthetic racing surface is dependent on the quality of the drainage system installed underneath it.

Three runs of perforated pipe running parallel to each other around the track were put in place, spaced about 20 feet apart. Then every 300 feet around the track the three perforated pipes were connected to a cross drain perforated pipe that ran towards the inside of the track. These cross drains connected to the Nyloplast manholes, which were spaced 300 feet apart.

Under the inner part of the track, just past the rail, a system of pipe was installed to gather the water coming from the track to the Nyloplast manholes. This system drained in multiple directions around the entire inner portion of the track. The pipe diameter ranged from 8” at the high point and grew in diameter to 30” at the low point.

At the low point of the manhole a 42” diameter pipe was placed across the track and over the back slope to an existing manhole.

Pipes and basins were also used around the clubhouse lawn areas for drainage of the newly established grades.

Elevation of the grandstand apron changed as well. This required an end-to-end drainage structure to empty the runoff of the trench and roof drains.

Rain Tests Result

The new track has already been put to the test. Shortly after the installation, a record setting rainfall poured down and the new drainage system passed with flying colors.

?EUR??,,????'??This meet has been extraordinary for us in so many ways,?EUR??,,????'?? said Nick Nicholson, President and CEO of Keeneland. ?EUR??,,????'??While we are proud of the many records that were set, we are even more proud of how well the Polytrack surface and ADS drainage system performed. It remained very safe throughout the meet, despite getting more than twice the usual amount of rainfall during the month.?EUR??,,????'??

Tori L. Durliat is communications manager for Advanced Drainage Systems in Hilliard, Ohio.