Bunker audits

Features - Course Maintenance

Managing sand depth is an easy way to improve bunker consistency

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April 18, 2011

As superintendents, we are faced with a myriad of daily challenges. One of the most constant challenges we face is our effort to provide quality conditions is our bunkers. Survey after survey of our clientele, be they members or daily users, invariably places “consistency of bunkers” at the top of the list of things that need to be improved. While managing moisture levels within bunkers is extremely challenging given the different greens’ complex configurations with their differing micro-climates, slopes, shade and watering characteristics, it is possible to effectively present consistent sand depth. At Wood Ranch, an American Golf Corp. owned private club in Simi Valley, Calif., we have established a simple yet effective routine process for producing consistency in our bunker sand depth.

When I arrived at Wood Ranch in 2008, bunkers were indeed at the top of the list, primarily for lack of depth of sand, causing many players to come in contact with the underlying soil. Before ordering any additional sand, we set about mapping out the existing conditions. This mapping must be done first to avoid ordering unnecessary sand. The mapping process is ongoing and forms the basis for all future work and allows us to focus in on the bunkers and indeed specific areas within the bunkers that need attention.


MAPPING
The first step in any effective program is to map out each bunker for current sand levels. A simple hand drawn map will suffice; however, if you have a GPS-based irrigation map or can access Google Earth or similar services, you can create a professional-looking template. Assign an experienced worker – a great project for assistants, foremen or interns – to divide each bunker into a grid of 2- to 3-foot sections. Utilizing a soil probe with a clearly-marked depth line (can be taped, scored or permanent marked in 1-inch increments), simply probe and record the depth of sand to either the liner or the sub soil.


The finished diagram may look something like this:


After our initial survey in 2008, we discovered that there was, in most cases, more than enough sand to get us to the depth we wanted. We were looking for a depth of 3-3.5 inches on the bottom of the bunkers and 2-3 inches on the faces.


REDISTRIBUTION
The next step after the initial detailed mapping was to assign staff and equipment to begin the process of redistributing the existing sand to the needed areas. A crew size for this project of six to eight has worked well. At Wood Ranch, we have 47 greenside bunkers and 28 fairway bunkers. A mechanical bunker rake with blade, several landscape rakes, regular bunker rakes, fine tooth leaf rakes for the finish hand rake and two to three soil probes were all that was needed.

A probe was used to check the depth and then our Toro Sandpro was used to move the sand around. The material was raked in and the Sandpro was driven over the bunker with the rear rake elevated to compact the sand. A final rake by hand and we were done.


REGULAR AUDITING IS KEY
Once the initial audit and redistribution has been completed, additional sand can more accurately be ordered. The next step is to monitor the movement of the sand in the bunker by probing weekly for a month. In that time, you can get a good sense of how the bunkers are being used. Again, utilize a staff member who is a golfer — usually, but not limited to, your assistants and interns — to probe and create a simple diagram of each bunker and where the sand has moved to.

It could be as simple as this:

 

OBSERVATIONS AND REGULAR AUDITS
Most of the sand moves toward the back of the bunker as the players rake themselves out. Most of the sand accumulates at low spots/easy exit points and is always far more than accumulates toward the greenside from actual explosion shots. After several months, it will become evident which are your key, heavily-used bunkers. Most of them will be at the front of the green or in the case of fairway bunkers, in the landing area. Fairway bunker sand movement is slightly different as a result of the constant use of a mechanical rake. Tight turns to maneuver around capes will result in sand sliding off the back of the rake and accumulating along the edges. Sand also tends to move off steep slopes if the rake drives too high up the slope. Reducing the speed at which the mechanical rake is driven, raking only the relatively flat areas of the bunker and avoiding sharp turns can all lead to less sand being moved around and accumulating in unwanted areas. Use of a longer hand rake by the mechanical rake operator, will allow them to rake the steeper slopes by hand and they will be less tempted to drive too high. Consider raking parallel to the edge on your cleanup hand rake three or four days out of the week and perpendicular to the edge on the other days.

The key to the whole operation is to be regular in your audits. After three years of our process, we are to the point that we have four quarterly total audits in which we do all fairway and green bunkers (75 bunkers). This takes us one week. We usually assign four to six people to work from 5:30 to 10 a.m. (lunch) and then add two more in the afternoon from 10:30 a.m. to 2 p.m., Monday through Friday. This allows us to get our course set up and mowing done. Total for the week is approximately 200 - 275 hours.

In addition to our quarterly audits are the eight monthly audits of our key, heavily-used bunkers. All 24 bunkers can be done in two mornings with six people for a total of 52 hours. Time varies with climate and we expect time to be longer after significant or sustained rain.

The final piece of the process is to communicate to your patrons. At Wood Ranch, I have a one-page weekly update in written form that is sent to staff and posted on our club’s website, as well as emailed to my Greens Committee who in turn email blast it out to their respective groups. I also update my golf course blog site with pictures of the process. I also ask that any bunkers of concern be made known to us through the monthly greens committee meeting. I have had great success by addressing a member’s specific bunker and this responsiveness has improved the overall view of the maintenance operation.

Will the audit stop the complaints? Absolutely not. But the audit is a simple and effective tool for improving the consistency of the depth of the sand in your bunkers.
 

Dave Coote is superintendent at Wood Ranch Golf Course, Simi Valley, Calif. Check out his blog at www.woodranchgc.blogspot.com.