Step 1: Address Drainage

As noted, our sand hazards have multiple shortcomings on top of an inconsistent depth and/or limited volume of sand.  An issue that arises during this portion of the "rainy season" creating the bunkers un-playable is the is the ponding of water.  Many of the bunkers either do not have internal drainage or have a faulty drainage system.  The bunker guarding the approach of #11 green has been the largest nemesis to our staff when dealing with weather events for countless years.  Installation of drainage is the first step in remedying the maintenance aspect and playability of this hazard.  Following drainage, the installation of erosion measures need to take place prior to installation of new sand.


During the closure for overseeding in October we began phase I of addressing the issues with the greenside bunker on Hole #11.  We shot grade, hand dug the trench, and installed 4" ADS drainage pipe & approved drainage gravel.  The trench was dug deep enough into the sub-grade to allow us to top up the channel with a minor amount of specified sand.  We will look to address additional bunker drainage issues as time and funding permits.


Attached are a few before, during, and after photos:

Dig Deep Enough and You Will Discover...

The bunkers have been a hot topic during my tenure here at Arrowhead Country Club.  It is gratifying to know that when I first arrived, the directive from the Green committee was to:  "Make it through the summer with the greens."  Now we spend a majority of our discussions on what in the golf world is considered, a hazard.  At the risk of deviating from the post, I would like to focus on bunker drainage.  As many of you can attest, the bunkers do not drain well after a weather event.  

After searching the archives, I found that the bunkers here at ACC were renovated in 2000 by an outside contractor.  That contractor was said to have installed "drainage" in numerous bunkers.  The bunkers on Hole #2 are included in that list and as you know, do not drain correctly.  After years of experience in construction, here are a few things I found fault with:

1.  The pipe selection.  The pipe installed was primarily developed for leach bed applications, not golf course drainage.  The pipe utilized could be purchased at any local hardware dealer and consists of a series of dual holes located on the bottom portion of a polyethylene shell.  N-12 would have been the correct application.  N-12 is a world standard, double walled, perforated, corrugated polyethylene drainage pipe with a smooth walled interior.  It is rigid enough to handle the weight of traffic and is more more accepting of water with the design.

2.  The trench width.  The trench was cut 6" wide to bed a pipe 4" in diameter.  This leaves very little room for error or gravel installation on each side of the pipe.  A minimum 8" trench should have been cut to allow for 2" of gravel on each side in conjunction with 2" below and above the pipe.

3.  The low point.  Drainage should be trenched into the lowest point of any bunker floor.  This point should be located where the sub-floor collects.

4.  Sand Quality.  If poor quality sand (containing high silt/clay percentages) is present, the drain will fail regardless of depth of sand and installation practices.

Pipe Utilized

N-12 Pipe

Another Interesting Discovery

It is always fun to find water bubbling up inside a bunker.  A major "no-no" in golf construction is to install irrigation pipe under or within a green or a bunker.  The damage due to a pipe failure could be very costly and take a feature out of play for the day or more.  As you can see by the photos, irrigation pipe runs through the right side bunker on Hole #3 green here at ACC.


This irrigation pipe relocation goes on the list of irrigation items to be addressed in the upcoming weeks, right below relocating the irrigation pipe that runs through the east side of the practice putting green.

Untimely Rainfall

Two and a half inches of rainfall on Saturday made for a very busy Sunday morning. The course handled the large volume of water considerably well, minus the havoc it wreaked within the bunkers. The last system passed thru at least 12 hours prior to opening, so carts were able to be utilized on the course beginning with the first tee time.

Removing standing water and repairing bunker washouts took the better part of the morning. I appreciate your patience while playing amongst the reconstruction. The practice round for the two day college tournament taking place March 1st and 2nd was underway and with very few open holes throughout the course, time was at a premium. I would like to applaud my staff for their hard work and sense of urgency when making the repairs and preparing the course for the upcoming tournament.

Practice Bunker Renovation

As sand volume and consistency in the bunkers has migrated to the forefront of topics of discussion, several important issues have to be addressed. The misconception that just adding additional sand of any type is not always the best solution. Both player input and science must be taken into account.

From the golfers perspective, the ball-lie is probably the most important aspect of the performance of the sand. Sand shape has an affect on ball lie, with angular sands providing better lie than round sands. A penetrometer test is used to evaluate ball-lie in the sand and will identify a certain sands propensity to promote what is commonly referred to as a “fried egg” lie. Color may be desirable from an aesthetic viewpoint, but is often dependent on local availability and can drastically increase the cost of the product without providing performance.

From a maintenance standpoint, it is important to factor in particle size analysis and infiltration rate. Bunker properties, such as, drainage rate, crusting, and set-up are negatively affected by very fine sand, silt, and clay. Specifications have been determined based on years of testing to provide guidelines for selection.

In addition to the sand selection, several other variables deserve consideration when evaluating bunker renovation. The cost of sand alone can range from $35/ton to $70/ton. Factoring in the current conditions of the bunkers- levels of contamination, internal drainage presence and level of operation, floor contours, and desired style can impact the outcome of the product.

Prior to major bunker renovations it is customary to create a "test bunker". This allows for real world testing and evaluation on a given property. The practice bunker at Arrowhead Country Club was selected for this reason. The photos below illustrate the in-house renovation process. We defined the new sand perimeter; removed the contaminated sand; excavated a drainage sump; re-countored the bunker floor to allow for consistent sand depth and provide adequate slope for drainage; lined the bunker floor with a geo-textile, permeable liner to prevent subsurface contamination but allow water to still perch through; secured the liner with staples on 6" centers where available to prevent lifting; installed the sand to a consistent depth of 6"; applied water and compacted.

Please feel free to leave your feedback on the performance of the selected sand. The hand tamping, additional moisture from the rains, and time will assist in the firming of the surface.

Before:

Redefining the edge and re-countouring the floor:

Installing the liner:

Installing the sand after securing the liner:

Initial compaction:

Final product: