Our golf club recently renovated our bunkers. The sand is deep and fluffy in some locations. How can we improve bunker playability?
It’s either the bunker sand or the bunker floor. I’ll discuss bunker sand below. Let’s discuss the structure of the renovated bunkers. I’m concerned about the shape of the bunker floor—the bottom of the bunker. The bunker floor should reflect the final sand grades (The surface of the sand when installed in the bunker). I prefer to construct a slight bowl shape to insure that subsurface water is directed toward bunker floor drainage piping.
If the bunker floors are not properly constructed, then they should be modified to the detail noted above. This modification involves the importation of a suitable fill, installation of new subsurface piping (as needed), and installation of new sand and liner. If the fill material has a high proportion of silt, the liner can be omitted.
I use the following procedure to evaluate the shape of the existing bunker floor. Choose a typical bunker, and rake the sand into a final sand grade (see above) that the golf superintendent and members can live with. Measure the distance between the top of the sand and the top of the bunker floor. The bunker floor must reflect the shape of the final sand grade. Deep sand creates inconsistent bunker conditions. Bunker sand should be six inches deep.
If the bunker floor is properly constructed, a uniform six-inch sand installation provides consistent playability. If the measurements are close, then your bunker floors are good. If the sand measurements don’t imitate the bunker floor at an even depth, consider a bunker floor rebuild.
If the bunker floor is OK, the sand can be removed without disturbing the liner. To avoid possible adverse political implications of sand selection, I advise golf clubs to choose three USGA sands that perform well. Install the three sands in a practice bunker, divided with wooden edging. Let the members choose between #1, #2, or #3. Don’t put a trade name on the sand. This sand selection process creates a consensus.
Golf course bunker sand can vary wildly. A reputable soil lab will sample bunker sand with a device that measures the penetration of a golf ball into a bunker sand. This information is compared to USGA bunker sand standards and playability characteristics determined. I’d test your current sand. The bunker floor may be fine, but the sand may not perform to USGA standards.
I’ve worked with golf course shapers (trained golf feature machine operators) capable of performing a bunker sand replacement, or bunker floor rebuild. I’ve set up contracts with skilled golf shapers performing the technical bunker construction, and the club staff doing the fine grading and sod installation under the shapers direction.