Random Photo: Added Drainage in a USGA green

September, 2019

This random photo post takes us back to 2019. When I arrived at Hazeltine, we had struggled with low spots on some of our greens. In the photo, you can see what this struggle looked like below the surface. We had some black layer in these areas, resulting in thin, under-performing turf. No matter what we did, we could never get these areas to dry out and improve.

At some point, I don’t recall when or how I heard about XGD drainage being put into USGA greens to solve low-point wet spots. We decided to pull the trigger on two of our putting surfaces. The third green, pictured above, has two tiers. The drainage being installed was at the foot of the lower tier. When the putting surface received any moisture, it would leak through the root zone into the low area, and because the low area was relatively flat, this moisture would sit.

To explain why this was happening, it’s essential to understand the dynamics of a USGA rootzone. When a USGA rootzone is flat, as you would find on a soccer pitch, the perched water table is predictable and performs in a way one would expect. As soon as slope is introduced, strange things start to happen. Suddenly, gravity can cause water to move laterally through the rootzone into low points. This trickle of water can then keep the low points at a much higher water content than other surface areas. This phenomenon can be replicated using a sponge.

In the video, the sponge is filled, and the ‘free’ water drains out. A larger’ head’ is created when the sponge is tilted, and the water travels to the sponge’s low point and drips out. As soon as the sponge is flattened, the water stops dripping. One can imagine this dripping of water, from the upper tier of a putting surface allows a significant amount of water to collect in the low area. Due to the dynamics of a USGA rootzone, the water never drains away unless field capacity is reached. Admittedly, my knowledge of soil dynamics is starting to be stretched, but there was no doubt we had a problem.

The idea of laying the XGD lines on top of the gravel layer was to give this excess water a place to drain in a way that is not subjected to a perched water table. It’s worked! Four years later, we no longer have issues with excess moisture in the low area of this green. The black layer is gone, the turf is no longer thin, and when the VWC is checked, the low and high readings are nearly the same.