At Turf Drainage Co. of America, we strive to meet proper seepage and drainage principles in all aspects of our drainage installations. That is why we have always advised against the use of gravel in fairway drainage installations. Superintendents find that the easiest way to relate to this is to compare it to the way they do greens’ drainage.
When greens’ mixes are sent into a certified USGA lab to test their ability to bridge with the gravel, the lab is trying to determine if the 15th largest particle in the mix will be held in place by the voids created by the gravel. As we all know, the particles that make up greens mixes are huge when compared to the particles that make up the native soils on most golf courses.
You will quickly find out that over 95% of all fairway soils will fail.
This can easily be tested at your course. Just send in a sample of your fairway soils to be drained, along with the gravel to a USGA certified lab, and let them check your native soil’s ability to bridge. You will quickly find out that over 95% of all fairway soils will fail. If it does fail, the correct solution is to use a properly sized sand as the backfill material. Let the designers at TDA show you how you can build a technically correct system at your course.