Feature Interview with Bob Randquist, CGCS
Bob Randquist has been the golf course superintendent at Boca Rio Golf Club in Boca Raton, Fla., since 1998. Previously he was the golf course superintendent for 19 years at Southern Hills Country Club in Tulsa, Okla., and for 2 years at Quail Creek Golf and Country Club in Oklahoma City. He has also served on the USGA Green Section Committee for the past 15 years.
During his tenure as superintendent at Southern Hills Country Club, he hosted the 1982 and 1994 PGA Championships, the inaugural 1987 USGA Womens’s Mid-Amateur Championship, and the 1995 and 1996 PGA Tour Championships. Bob is currently teaching a seminar for the Golf Course Superintendents Association of America titled ‘Hazardous Duty……Basic Bunker Maintenance’, and was recently elected to serve a 2 year term on the Board of Directors for the GCSAA.
A native of Anadarko, Oklahoma, Randquist graduated from the University of Oklahoma in 1972 with a bachelor’s degree in metallurgical engineering.
The purpose of his seminar ‘Hazardous Duty…Basic Maintenance’, much of which he has graciously allowed GolfClubAtlas.com to reproduce in this three part Feature Interview, is to help those attending gain knowledge on bunkers, in part by:
- Understanding the design strategy that bunkers provide for the game of golf.
- Understanding factors that golfers use to form opinions regarding bunker playability.
- Learning how bunker design and construction impact bunker maintenance.
- Identifying how sand selection and depth impact bunker maintenance and playability.
- Identifying how surface related bunker maintenance practices affect playability.
- Identifying methods for solving problems associated with poorly designed or constructed bunkers.
PartIII of this Feature Interview centers on solutions for problem bunkers.
What is a ‘problem bunker’?
Most golf course architects and golf course builders make a concerted effort to design and construct bunkers that golf course superintendents can maintain with normal bunker maintenance procedures. Despite their diligent efforts, some bunkers inevitably present ongoing bunker maintenance challenges that cannot be solved with routine bunker maintenance practices. These bunkers often are referred to as ‘problem bunkers’.
What are the primary solutions for problem bunkers?
Long, steep bunker faces and slopes are often used to create a severe degree of difficulty, enhanced strategy, or striking visual artistic appeal. Though these bunker design features provide added interest to the game, bunkers with slopes greater than 30 degrees usually are prone to problems resulting from sand sliding down from the bunker slopes and into the bottom of the bunker. This sand displacement is usually caused by excessive water flow, wind erosion, or golfer and golf course maintenance traffic. In the case of excessive water flow, once the sand is completely washed off the sloped portion of the bunker floor the water flow begins to erode the soil that forms the bunker floor. Depending of the composition of the material used to construct the bunker floor, soil, silt, or stone often flow down onto the sand deposited at the bottom of the bunker. If the resulting silt and soil layer is not removed before the sand is pushed back up on the bunker slope, the bunker sand becomes contaminated with undesirable materials in a very short period of time. This problem can be especially severe when surface flow from areas surrounding the bunker is not directed properly and flows into and through the bunker.
High winds, golfer traffic, and raking procedures can also cause sand to slide down severe bunker slopes. This type of sand displacement is usually associated with sands that have high percentages of spherical particles, and a strong resistance to the sand being packed tightly. Bunker sands that have very fine particle sizes and relatively light weight particles can also be displaced by high winds, either collecting at the bottom of the bunker or being deposited outside the bunker. If not corrected properly, this sand displacement leads to inconsistent sand depth, inconsistent sand purity, high potential for sand surface crusting, and problems with bunkers not draining adequately. A significantly increased amount of labor is usually required to produce the consistent desired playing conditions in these problem bunkers.
When bunkers drain poorly and water tends to stand in bunkers for more than an hour or two after a rain or irrigation event, golfers are usually of the opinion that bunker playing conditions are unacceptable. Bunker drainage lines or systems that are improperly designed, installed, or damaged during or after construction cause many bunkers to become problem bunkers. Most golf course superintendents solve this problem on a temporary basis by pumping standing water out of these bunkers with small trash pumps. This practice is very labor intensive, especially if a large number of a golf course’s bunkers do not drain properly. Though standing water in the bunkers may be removed, the bunker sand is often excessively wet and firm for extended periods of time as excess moisture evaporates from the sand profile and the sand slowly dries. This situation usually produces poor bunker playing conditions and leads to a golfer’s extreme unhappiness regarding the playing condition of the bunkers.
The primary solutions for these type of problem bunkers are: 1) re-contouring slopes around or in bunkers; 2) repairing or adding bunker drainage lines or systems; and 3) installing and maintaining bunker liners.
Please discuss each of these three solutions separately. First, let’s discuss re-contouring slopes around or in bunkers.
Re-contouring slopes around or in bunkers sounds like a fairly simple solution for eliminating problems caused by bunker slopes that are too steep to easily maintain.
However, golf course superintendents should consider several factors before recommending this method. The golf course architect’s design strategy, artistic intent, and intended degree of difficulty may all be severely compromised by changing the contouring around or inside a bunker. Changes of this nature should not be taken lightly or done to satisfy only a small group of people. These issues should be examined closely and discussed thoroughly by a golf course’s governing parties before major changes are approved. If at all possible, the original golf course architect should be consulted regarding any proposed changes to bunker complexes.
Re-contouring works best in situations where water is eroding bunker slopes as it flows from above the bunker and into or through the bunker. The turf area above the bunker and the bunker lip can often be raised enough and reshaped so that water flow is completely diverted around the bunker. This can often be accomplished without making major changes to the architectural style and intent of the bunker and its surrounding area. The re-contoured bunker complex should match as closely as possible the design style and appearance of the golf course’s other bunker complexes.
Internal bunker slope modification requires that the degree of slope of the bunker floor be reduced. Usually, a significant amount of soil has to be moved and reshaped to accomplish this task. Soil is usually added to the bottom of the bunker and the lower portion of the bunker slopes, and these areas are reshaped to form a new bunker floor with a lesser degree of slope. Sand is much more likely to remain in place on the bunker slope and the potential for sand contamination is reduced. However, the bunker becomes shallower and the difficulty for playing bunker shots is often reduced. If changes in bunker design and playing conditions are acceptable, these modifications can make basic bunker maintenance much easier and less expensive.
A more radical procedure for eliminating problems with sand erosion on bunker slopes involves changing sand faces and slopes of bunkers to grassy slopes or revetted grass bunker walls. Some golf course architects and golf course superintendents prefer that bunkers have sand only on a flat bottom bunker floor, with turf on all sloped areas surrounding a bunker and no sand flashed up on bunker slopes. Since bunker sand remains in place on the flat bottom of a bunker, problems with sand contamination and the need for sand depth adjustment are greatly reduced. However, this bunkering style does present some other maintenance challenges. Most grassy slopes associated with his architectural style of bunkering are usually too severe to be mowed with riding mowers and often have to be mowed with labor intensive procedures that utilize weed-eaters or fly-mowers. Also, growing quality turf can be difficult on severe slopes that are droughty, difficult to fertilize uniformly, and often receive limited sunlight due to directional orientation. Revetted (bunker walls built by stacking sod) bunker faces and walls require fairly low maintenance input, but usually begin to deteriorate over time and must be reconstructed every 3 to 5 years. When these design features are an integral part of the original golf course design and construction, the labor requirements and costs required for bunker maintenance are usually much lower than for golf course bunker designs that feature sand flashed up on bunker slopes. Before recommending such a complete change in bunker design style on an existing golf course just so that bunker maintenance costs can be reduced, golf course superintendents must thoroughly examine and analyze every effect of altering a golf course’s bunker design style. How much actual reduction in bunker maintenance costs will be realized? Will the golf course architect’s design strategy, visual artistic appeal, and desired degree of difficulty be changed too radically? Will golfers be comfortable with this degree of change in bunker design style? Does the original golf course architect agree with these changes in bunker design style? Should all of the golf course’s bunkers be modified or just the problem bunkers? Obtaining educated, unbiased answers to these types of questions is critical if the correct decision is to be made regarding whether or not to resolve bunker maintenance problems by re-contouring bunker slopes around or in bunkers.
Secondly,please discuss repairing or adding bunker drainage lines or systems as a solution for problem bunkers.
Well designed, installed, and maintained bunker drainage lines or systems are a necessity if consistent bunker playing conditions are the desired standard. Standing water in bunkers or bunker sands that drain poorly and dry too slowly make it very difficult to achieve and maintain acceptable bunker playing conditions. Well-placed bunker drain lines can also be used to alleviate problems associated with bunker sand washing off of severe bunker slopes.
We can separate bunker drainage system shortcomings and failures into two general categories: 1) water is not adequately collected into the bunker drainage system; and 2) water is not adequately discharged from the bunker.
- 1) Possible causes for water not collecting properly in bunker drainage systems are poor bunker sand drainage properties due to sand type, excessive crusting on the bunker sand surface, silt or fine particle contamination of the bunker sand, crushed or clogged drainage pipe, poor placement or insufficient volume of drainage pipe, or a combination of more than one of these factors. The first step toward solving these problems is to dig a few inspection holes in a bunker, locate the bunker drainage pipe, and determine the condition and flow capacity of the drainage pipe. If the bunker drainage pipe is crushed or filled with sand and silt it should be repaired or replaced depending on the extent of the damage. If the bunker drainage pipe has too small a flow capacity it should be replaced with larger size drainage pipe. If the drainage pipe is not in the lowest point of the bunker floor it should be relocated to that position. If the bunker drainage pipe appears to be in good condition, is well located, and has adequate flow capacity, water should be run into the drainage pipe for a long enough period of time to determine if there is any restriction to flow downstream from the bunker. If the drainage system is flowing well the problem with poor bunker drainage is due to the condition of the bunker sand. This problem can often be solved by completely removing a section (2-3 feet wide by 5-20 feet long) of the bunker sand profile above the bunker drainage line and replacing it with bunker sand with adequate drainage properties. This method works especially well when dealing with surface crusted and silt contaminated bunker sands that have developed in low areas of a bunker above the drainage lines. Care must be taken to ensure that the new sand has playing and appearance characteristics that are consistent with the existing bunker sand. This can usually be accomplished by raking some of the surrounding existing bunker sand onto the surface of the new sand and blending them together in a thin layer. This procedure may have to be repeated every one to three years in severely sloped bunkers that are prone to bunker floor erosion problems. If consistent playing conditions and adequate bunker drainage cannot be achieved using this method, complete removal and replacement of the bunker sand should be considered.
- 2) Possible causes for water not adequately exiting from internal bunker drainage systems are crushed or severed drainage lines outside the bunker perimeter, blockage of the bunker drainage system discharge point, vegetative root blockage of the drainage line, or inadequate fall from the internal bunker drainage system to the bunker drainage line discharge point. It is surprising how many times bunkers drain poorly for the simple reason that external drainage lines are not functioning properly. External bunker drainage lines are often cut or damaged during irrigation installations or repairs, crushed by heavy equipment traffic, clogged by invasive tree roots, or blocked by some type of an obstruction at the discharge point. By digging a few inspection holes along the external bunker drainage line and examining the condition of the drainage pipe, these types of problems can be easily detected and repaired. A few hours spent correcting fundamental drainage problems can prevent a much larger labor commitment necessary for repeatedly pumping water out of bunkers. When bunker drainage lines and systems are installed without the degree of fall needed to facilitate gravity induced water flow from the bunker, these are the possible solutions that should be considered: a) if terrain elevations surrounding the bunker vary enough, replace the drainage lines with new lines that provide adequate fall for good gravity flow in the drainage system; b) if the terrain surrounding the bunker is flat and does not allow for installing drainage lines with adequate fall, the bottom bunker floor may have to be raised enough to provide the amount of fall the drainage system needs to function correctly. If this solution is not acceptable due to architectural considerations, then c) consider the possibility of using bunker drainage systems based on siphon or catch basin/sump type drainage principles. Many of these types of systems that are commercially available work very well, depending on the quality of the design and installation of the system. Golf course superintendents should thoroughly test these systems in a limited number of bunkers on their golf course before recommending a bunker drainage system that will correctly solve this type of bunker drainage problem.
Adding drainage lines and systems can also be used to prevent surface water from flowing down from above the bunker and eroding the sand and the bunker floor of the bunker slope. Subsurface interceptor drain lines can be installed above the bunker to catch water before it reaches the bunker lip, and discharge the water in an area away from the bunker. This may not be acceptable in some situations due to depressed or droughty areas in the turf usually associated with these subsurface interceptor drains. This can especially be a problem if this type of drainage is installed close to greens in an area that is regularly in play for golfers. A better solution is to install one or more subsurface interceptor drains in the bunker floor on the slope below and parallel to the upper lip of the bunker. These drainage lines are then connected to the bunker drainage lines in the bottom of the bunker. If the bunker sand has relatively good drainage properties and later can easily infiltrate the sand and reach the interceptor drainage system, this method produces extremely positive results. Golf course superintendents should experiment with this method in a limited number of bunkers to determine how well it will work in their golf course’s bunkers. In many cases the amount of sand that washes down the bunker slope will be significantly reduced.
When bunker drainage problems are correctly diagnosed and eliminated, basic bunker maintenance becomes much less Hazardous Duty for the golf course superintendent.
As the third and final solution for problem bunkers, please discuss installing and maintaining bunker liners.
Bunker liners are installed in some bunkers as a barrier between the bunker floor and the bunker sand. If properly installed, bunker liners can prevent erosion of the bunker floor and significantly reduce contamination of the bunker sand caused by either water erosion of the bunker floor, or gradual mixing of the bunker sand with the soil, silt, or stone that make up the bunker floor. There are basically two commercially available methods (with several different variations) for establishing this barrier between bunker floors and the bunker sand: 1) geotextile fabrics are used to provide the barrier; 2) soil bonding and/or sealing agents are incorporated into the top portion of the bunker floor soil profile, or a combination of soil bonding and/or sealing agents and aggregate materials are coated onto the bunker floor to provide the barrier. Each method has advantages and disadvantages when utilized for solving contamination and erosion problems associated with problem bunkers.
- 1) Geotextile fabrics with the right weave and composition can provide an excellent barrier between a bunker floor and the bunker sand. Even though the bunker sand may be completely washed off a steep bunker slope, the fabric protects the bunker floor and prevents erosion. The bunker sand tends to remain pure and uncontaminated by materials from the bunker floor. A geotextile fabric barrier also traps stones or shells in the bunker floor material and keeps them from moving upward and mixing with the bunker sand. Some bunker barrier systems incorporate a layer of gravel underneath the geotextile fabric to further facilitate water movement into the bunker drainage system. Though geotextile bunker liners can eliminate many bunker problems, there are some potential problems associated with their use that must be considered before deciding to install them in a golf course’s bunkers: a) installation of the geotextile liner must be done correctly to ensure that it stays in place on the bunker floor; b) sand depths should be a minimum of 2 Ã‚½ to 3′ to prevent players from hitting through the sand and striking the liner. Most golfers express concern after hitting a bunker liner with their club, noting that the club tends to stop suddenly rather than bouncing as it normally does on a soil based bunker floor. Sand depths of at least 4′ are usually recommended in bunkers with liners. As a result, the selection of a bunker sand that packs well becomes critical, unless a high degree of difficulty for playing bunker shots is acceptable; c) extreme care must be taken if mechanical bunker rakes are used to rake bunkers with liners, or when using a front mounted plow blade on a mechanical bunker rake to push sand up on the bunker slopes. Rake and plow blade attachments on mechanical rakes can snag the liner and displace it from the bunker floor or tear the geotextile fabric. Most golf course superintendents choose to hand rake bunkers when geotextile fabric liners are used in their golf course’s bunkers. Hopefully, the recent introduction of some new bunker rake attachments and bunker hand rakes that are configured to prevent this snagging of the fabric liner will solve this problem; and d) care must be exercised to ensure that bunker drainage is not impeded by the geotextile liner. Very fine size sand particles or silt particles can sift into the geotextile liner, eventually impeding the potential water flow through the liner. This potential problem can be easily prevented by not covering the bunker drainage lines in the bunker with the liner during the installation process, or by selecting sands that have low silt and fine sand particle content.
2) Various types of soil bonding agents or coatings can be used to stabilize a bunker floor soil and reduce potential erosion of the bunker floor. Some bonding agents are incorporated into the top layer of the bunker floor soil and help to ‘cement’ the bunker floor in place. Some polyurethane compounds are simply sprayed on the bunker floor to provide a protective coating that repels water and prevents water from reaching and eroding the bunker floor. Some bonding agents are mixed with fiber particles or other aggregate materials such as fine sand or gravel, and then coated onto the bunker floor to a specified thickness. The intent of all these methods is to provide a barrier or liner between the bunker floor and the bunker sand. If properly installed these types of liners can form a barrier that significantly reduces contamination of the bunker sand as a result of bunker floor erosion. As with geotextile bunker liners, care must be taken to ensure that bunker maintenance procedures do not damage and compromise the effectiveness of the liner material. Most golfers do not find striking these bonded surfaces with a golf club to be objectionable, and sand depths can be shallower that those used in bunkers with geotextile liners. Because most of these types of liner materials are designed to repel water and prevent water infiltration, bunker drainage lines should never be covered with these materials during the installation process.
Due to the significant costs for adding bunker liners and the potential effects on a bunker maintenance program and bunker playing conditions, golf course superintendents should carefully test and evaluate bunker liners in a limited number of their golf course’s bunkers before recommending that they be installed in all of a golf course’s bunkers. Bunker liners may provide an ideal solution for some problem bunkers. For some other problem bunkers they may not provide the correct answer.
From your thirty years as a golf course superintendent, what conclusions have you drawn for a basic bunker maintenance program?
The guidelines for developing a basic bunker maintenance program are:
1) Develop an understanding of the architectural purpose and intent of the golf course’s bunkering.
Golf course superintendents need to be able to discuss bunker design and maintenance issues with golfers in terms that they understand.
2) Develop a well-defined standard for bunker playing conditions and the desired degree of difficulty for playing bunker shots.
Golf course superintendents need to provide the leadership necessary to help golf course owners, green committees, golf professionals, club managers, department supervisors, and golfers achieve consensus regarding standards for bunker playing conditions and maintenance programs.
3) Thoroughly evaluate existing bunker playing conditions and investigate, identify, and recommend bunker maintenance methods that will produce the established standards for bunker playing conditions.
Since they are the persons primarily responsible for maintaining bunkers, golf course superintendents should work diligently to ensure that they are the most knowledgeable available source of information when bunker issues are discussed.
4) Implement methods and properly train and supervise golf course maintenance employees so that established bunker maintenance standards are achieved.
The development of a basic bunker maintenance program is useless if this basic guideline is ignored or taken too lightly by the golf course superintendent.
There are no magic formulas or perfect templates for developing and implementing basic bunker maintenance programs that will produce bunker playing conditions that satisfy every golfer and every golf course superintendent. Opinions regarding the nature and purpose of bunkers are too diverse to allow everyone to agree that bunkers should only be maintained in one particular style. One of the most endearing qualities of a round of golf is that the good shots and bad shots, the emotional highs and lows, and the exposure to hazardous conditions that we experience in golf mirror the challenges we face in living our everyday lives. Golf can help us learn lessons about avoiding, escaping, and even appreciating hazards placed in our path. With an open mind, a willing spirit, and a diligent effort, golf course superintendents can learn to appreciate and enjoy the Hazardous Duty associated with basic bunker maintenance.
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