Roll Tide's new field drains and nurtures turf

Upgrading the turf for the University of Alabama’s football team required a non-typical underground drainage system. Because the Crimson Tide usually makes it to playoff games later in the season, the decision was made to have a drainage system under the turf at the Bryant-Denny stadium that would also provide heat to support grass growth during cooler months. The key to the design was a network of corrugated high-density polyethylene (HDPE) pipes. There is now nearly a mile and half of perforated and non-perforated pipe draining and warming the field.

“College football has changed,” said Jon DeWitt, CSFM, director, athletic grounds for the University of Alabama. “It’s a multimillion-dollar business, and we needed a field to perform at that level.”

Upgrading the field

In July 2024, the new $6.2 million field was named for Coach Nick Saban, who retired from the university earlier that year with a 201-17 record during 17 seasons. The pipe is hooked up to the SubAir (Graniteville, SC) Sport System with TurfWatch Technology that enables water to be quickly drained and push air into the root zone to promote turf growth. This patented control system uses 14 in-ground, wireless sensors that relay subsurface conditions 24/7 to the central control through a secured communications network. The data automatically engages the SubAir Sport System to maintain ideal subsurface conditions.

The SubAir system uses gravity flow plus suction to remove excess water from above, speeding up the rate of drainage while also reducing ponding. The system pushes up fresh and heated air to the roots of the new NorthBridge Bermudagrass, helping to promote a high-quality playing service that will remain healthier even in cooler months and also recover faster from heavy use.

The system was designed and installed by Precision Turf LLC, based in Sugar Hill, Georgia.

“We did the new field renovation for the Coach Saban field, which is a sub-air system that will have forced heat and suction,” said Brandon Wilson, Precision’s project manager for the project. “It is very state of the art, definitely a very unique project for everybody. There’s a heavy, very dense drainage layer there. But that system will be able to handle any amount of rainfall precipitation. You’ll never see a drop of water anywhere on the surface of this.” 

Utilizing HDPE pipe

The system is made up of 7,000 feet of six-inch perforated corrugated HDPE pipe laid out in a grid pattern, along with 580 feet of 24-inch and 180 feet of 30-inch non-perforated HDPE pipe. The smaller diameter pipe forms a collection system that can also feed warm air upwards into the root system. The Goldflo pipe from Prinsco, Inc. and supplied by Superior Drainage Products, Inc. provided the required watertight performance. The watertight integral bell and spigot coupling system also allowed a quick and easy installation, reducing costs and increasing efficiency. The bell and spigot are verified to ASTM D3212 10.8 psi laboratory test. The pipe’s Manning’s N value is 0.012, allowing for greater flow capacity and reducing sediment and debris build-up.

The field surface of the 100,077-seating capacity stadium has natural grass playing turf with a synthetic turf sideline.

“We started off with a 30-inch solid pipe that runs up to a 24-inch diameter piece,” Wilson said. “That 30-inch takes the bulk of the water and (pushes) that air volume into the field. It runs to a 24-inch solid pipe as well. That gets the trunks to tie-in all of our six-inch lines. We have more than 7,000 feet of six inch on a 10-foot center. This project required a watertight, very sealed up coupling system, and that is what Prinsco had for us. They made fittings that are custom for this project and ensured us that if there was something we needed that was special or not in the catalog or the product data, they could make it happen.”

The project earned the company the Project of the Year award from the Plastics Pipe Institute, Inc. (PPI), the major North American trade association representing the plastic pipe industry. Every year the association’s membership reviews and votes on Project of the Year for each of the five PPI divisions - Building & Construction, Drainage, Energy Piping Systems, Municipal & Industrial, and Power & Communications. Prinsco is a member company of PPI.

“Providing a safer playing surface by installing an underground drainage system is becoming more and more popular,” said Dan Currence, P.E. director of engineering for PPI’s Drainage Division. “This is at all levels from schools and colleges to the pros. When a new field is being installed, it is practical and cost-effective to also put in the HDPE corrugated pipe that will help to quickly drain the field. And at the University of Alabama, they did it one better by using their system to also promote turf growth. 

“HDPE pipe has many attributes,” he continued. “It is corrosion-proof, has a rated use life of more than 100 years, and is sustainable.”