One year after the installation of Exlterra’s GEPS® process on one of its fairways, Rougemont Golf Course has decided to test this technology on a green for the first time. Greenkeeper Thomas Olivier gives us an overview of the first year of use and explains why this innovative system will be installed on a green and a new fairway.

A year ago, Gazon Sport Pro H24 took you to Territoire de Belfort to follow the renovation work at Rougemont Golf Course, specifically the installation of Exlterra’s GEPS system. This system uses vertical polyethylene rods (ranging from 1.5 to 12 meters), implanted in the soil, allowing moisture to be transferred from the surface layers to the lower layers. One year later, we visited Thomas Olivier, the greenkeeper who had welcomed us, to assess the situation. The system proved to be more effective than expected, and additional installations were carried out.

In 2022, Exlterra’s partner Terenvi installed the GEPS process on the 5th fairway at Rougemont-le-Château Golf Course. “For me, the trial is relatively conclusive,” Thomas Olivier says with a smile. The first year, which was expected to be the most challenging after installation, turned out well with a decent winter during which the precipitation was well absorbed by the system. But it is the effect of GEPS during summer that surprised the greenkeeper the most.

And Frank Muller, the CEO of Exlterra that invented and patented the GEPS process, explained it to us in our previous article on this technology: water is not simply absorbed, it is redistributed. This is why, in summer, the fairway benefiting from GEPS technology was the healthiest at Rougemont Golf Course, as shown in the aerial images.

An experiment repeated on a new fairway and… a green

The system has impressed and provided solutions to basic issues, namely excessive moisture in certain areas, making it difficult for machines to access the fairway at certain times of the year. To such an extent that the system has since been installed on two other fairways (1 and 12) and… a green (green 1). 

The 12th fairway was also facing excess moisture, and mowing on unstable soil could leave traces, as shown in the accompanying photo.

With the soil occasionally being too wet, mowers can damage the 12th fairway.

To address this, the task was significant: 686 holes were drilled, including 17 at a depth of 40 feet and 49 at 20 feet. Impressively, the work lasted only one week in total, despite the fact that Exlterra’s teams sometimes had to deal with a capricious substrate that closed too quickly, not allowing enough time to insert the drill before the hole closed up.

Regarding the green, as Thomas Olivier explains, the issue is essentially the same with excessive moisture due to the greens’ construction itself. The granulometry of the original draining layer is not good. The layer of sand above the draining layer is not homogeneous, with a thickness ranging from 12 to 24 inches in some places, causing drainage and water stagnation problems.

In total, on the 5,425 square feet green, 103 holes were drilled, including 6 at a depth of 40 feet. To avoid damaging the playing surface, Exlterra’s machines were placed on anti-tear plates. After the work on the green, Olivier Thomas, once again, expressed satisfaction with the results obtained. The soil permeability has improved, and machines and carts can now move on the green at any time. 

During dry periods, GEPS maintaining moisture in the soil allows for a 50% reduction in irrigation, and the vegetative cover shows no yellow marks, unlike the areas equipped with conventional drainage. Mechanical aeration is no longer necessary. Finally, the grass has better rooting and density. Olivier Thomas also noted a decrease in diseases on the equipped green. All signs seem positive for the GEPS process.

You can watch a video about Exlterra GEPS here: https://youtu.be/0eF4rBcVFS0?si=pSRy3dmEBaOtAbjd