RAIN, Does it expose poor bunker design

[Patrick_Mucci]

Yesterday, a severe thunderstorm drenched parts of a parched New Jersey.

At a golf course that I'm familiar with, the bunkers were virtually decimated.

The bunkers were not of the type with flat bottoms and grassed faces, but almost universally bowled.

In addition, the ground around many of these bunkers directed surface water into, rather than away from them, further eroding their faces, until a mix of mud and sand rested in the gravitational center of the bunker with little sand remaining on the slopes.

It appeared to me, that the club could try to respread the sand and mud mix, but in doing so the playability of the bunkers would change, and..... to properly restore them, they would have to be excavated and resanded.  However, another torrential rain storm would produce the same results.

While torrential rain will damage bunkers, the damage I witnessed was......SEVERE, and I would conclude from this observation, that the bunkers were improperly designed and built.

Does RAIN, expose design and/or construction flaws ?

[Jeff_Brauer]

Pat,

Any sloped bunker will wash sand away, especially if overland water comes over the top.  Herringbone drain tiles near the top, and the new fabrics help a bunch, but gravity isn't just a good idea, it's the law, and sand will wash down if the rain is hard enough.....

I tend to do flatter sand bunkers in rainier - and windier - climates, but have even seen flat sand bunkers wash in a big enough rain.  Its the same amount of water coming down whether coming down a grass or sand slope!  I got a call today from my new course in Minnesota, where the new sod has washed down the banks in a few big rains, so washing sand is not the only problem, either.

Here in Dallas, I find that if only the edges of the bunkers flare up steeply, and the base of the bunker is in the 10-15% range, they will withstand most rains, and wash out about 3 times per year.  This, along with consideration of mechanical trap rakes, tends to make bunkers bigger in scale, and more "non golden age like" if you will, but it is a compromise made after years of experience.

All bunker design is a bit of a compromise, really.  If the Owner wants the "MacKenzie look" then the super needs to plug in about five unscheduled "sand shovelling days" annually to get that look.  Flat bunkers have visibility problems, and in my mind, are not as attractive a feature, in most cases.

So is damage representative  of flawed design?  Not IMHO.  Rather, it is a conscious decision of what maintenance problems to give a super versus the look an architect wants.  That decision should be different, likely, for almost every course to best fit its goals.

[Patrick_Mucci]

Jeff,

I understand your statement regarding the equality of sand versus grass, but I was talking about the ground around the bunker directing surface water into the bunker.

Take for example a perfectly flat piece of land, a dogleg left, and the placement of bunkers on the outside and far corner.
If one builds up the earth, for the purpose of installing flashed bunkers, the earthen work into which the bunkers are placed can and does direct water into them, unless some unique design and construction features are inserted.

If the bunkers weren't flashed so much, the earth work into which the bunkers are placed can direct the water away from the bunkers.

Lastly, if the bunkers were blind, pits construced on the flat land, construction could insure that surface water was directed away from the bunker, not into it.

What I witnessed was a bunker design that must fail, everytime it rains, not three times a year.

[Jeff_Brauer]

In your example (real or fictious in the second post) how much land was draining into the bunker?  If the earth is built up on flat ground, I would usually flash the sand 2-4 feet, and only let about 2 foot of grass above flow into the bunker.  Any more of either, or any concentrated spots, like a valley between two mounds behind the bunker tend to wash.

For similar reasons, I usually do very simple, straight, front edges to the bunkers.  Putting a mound or roll in front of the bunker blocks vision, and requires the sand behind it to flash even higher, leading to more washes.

Granted, any flash bunker has some potential for wash.  On the other hand, they look so good compared to sunken pits, I think some compromise is worthy.

[Patrick_Mucci]

Jeff,

I think some of the flashing is excessive, and I don't think they ever considered the effects of a good storm or prolonged rain.

The earthen works into which the bunkers are placed are rather large.

[B. Mogg]

There are ways (and not that difficult) of keeping flashed sand faces, even fairly extreme ones, from washing down.

1. Sand selection is critical.
2. Keep all external drainage water from going into the bunkers. This will also limit placement at the bottom of big slopes for instance.
3. A lot of internal drainage work.

It can be done, we have flashed up bunkers in the most demanding of tropical climates with zero washout (and without bunker wool!). Took us a while to work out how (we are not that bright of course)

No need to overly limit the aesthetic look of your bunkers just due to rainfall.

[BV]

Jeff Brauer's comments are so fine here.

Bunkers as golf evolved in the linksland were and are the way they are because nature shaped them.  Just putting in a style of bunker in an area where it doesn't fit is well, rather.....
Also, Mr Mogg should certainly know a thing about rain-resistant bunkers  


And I think the answer to Patrick's original question is twofold
-The problem as described is Maintenance/Construction  regarding that site
-Weather bad enough will permanently alter any bunker, ergo the bunkers of old and how they got that way.

[Patrick_Mucci]

Bmogg,

I think # 2, coupled with the bowled shape of the bunkers is their undoing.  Surrounding surface water is directed INTO rather than AWAY from the bunkers

BV,

On a flat site, there are no natural flash bunkers, they have to be created, and the choice has to do with the decisions Jeff mentioned, but, there is a price to pay, and from what I witnessed, they'll be paying it eternally.

[texsport]

Mr. Brauer's idea of flashing 2 feet of sand with 2 feet of grass flowing down into the bunker is the only workable solution in south Texas. Here, the flat land and gumbo/clay soil guarantees regular washout of bunkers were sand is thrown up at too great an angle or distance. I can't count how many bunkers I've seen rebuilt over the years down here because of an architect who tried to build steep faced bunkers which were more asthetically pleasing.

Texsport

[Patrick_Mucci]

Texsport,

One would think that word would travel fast, and that the failure of a bunker style to tolerate rain, would bring about its immediate demise.

Why do you think the architects continue to force this bunker style, that is a proven failure, into new designs ?

[John_D._Bernhardt]

Well said Jeff. It really is an engineering issue. I really do not believe you can put much slope at all in an area which has regular 1/2 inch plus rains in 2 hours or less. There is a new cloth material that seems to improve the situation, but I believe ultimately it will take significantly increased maintenance to keep any slope to the face of the bunkers. My club has some clay issues too which accentuate the problem and a super who has not told the truth in a decade.

[RJ_Daley]

It seems to me that we have two architects with somewhat different points of view about bunker construction and performance in rain events.  Certainly, they have designed and constructed in widely differing climates and terrain.  Brett's rather confident comments that even prominently flashed bunkers can be made to perform in big rain events if certain factors are dealt with properly causes me to wonder if indeed the heavy rain climates he works in have given them a superior knowledge of bunker design and construction.  Obviously Jeff is no slouch and he has great experience across the US in many types of terrain and climate, yet he seems almost resigned to the eventuality of failing bunker performance if they are stressed in rain events to any expected degree of big rain from time to time.  Are these gents speaking of the same standards of design, or are the maintenance standards due to their world locations, vastly different?

Bold style bunker designs can be found in classic courses like Crystal Downs.  I would be very interested to see an historical description of the bunker maintenance over the many years in relation to their endurance to withstand some very heavy rain periods in that locale.  Has significant reconstruction of shape, drainage slopes within the bunker surrounds, and internal drainage been added over the years?  Or, has the basic construction of them remained relatively the same?  Perhaps Doak or DeVries can speak to that.  The same questions of the maintenance and reconstruction of other famous older courses like Ross's at Pinehurst and other locations would be illuminating in relation to if they have faced the inevitable wash-outs that Jeff describes, or the endurance of a "special" construction skill and knowhow that I believe Brett is referring to...?

Do other archies and builders want to take a shot at commenting on this?  

[Justin_Zook]

Patrick Mucci-

Rain definately exposes poor bunker design and construction.  At the course I work at, a central PA Morrish design, the bunkers are all like the ones you initially described.  Most of them wash out in heavy rain and even some wash out, while less severely, in light rain.  The club tried to save money with a cheap design/construction firm, but that has only wasted and lost what we saved because of use needing more manpower and equipment to deal with the problem.  Now we have been lucky/unlucky because it hasn't rained on my course in about a month, and we are opperating under extreme drought restrictions with our irrigation.  We have great bunkers but brown grass .  Anyway, Mr. Mucci, you are 100% correct!

[Joe Hancock]

Great bunkers with brown grass...what could be better?

Joe

[Willie_Dow]

Pat

To my way of thinking, good design or bad design takes on evolution.  Having watched Kittleman/Valentine over the years showed that knowledge of raindrops create good bunkers, and justify their location.

[Jeff_Brauer]

RJ,

I think Brett and I have about the same take on bunkers.  I, too, have found cutting off external drainage, putting a full herringbone of drain tiles up the bunker slopes to the top, and using a heavy, angular particled sand, as opposed to a round one (when you can find it economically) are all part of making flash bunkers reasonably practical.  At some point, I believe you still need to soften the slopes to a maximum  25% at the edges, quickly going down to no more than 15% in the bunker base.  My goal isn't to eliminate washouts completely, but to keep them to just a few a year, in the heaviest rains.

BTW, I did build one facility in Indonesia, near Brett, and recall they have about 100 inches of rain annually, which puts even Houston to shame!  Of course, its not quantity, its how much of that hundred inches you may get in an hour!  I recall getting back to my project and finding someone had figured my drain pipe sizing was too big.  During my stay, we had a rain that proved my original sizes were correct, and I stood there watching the flow take a fairway out during construction.

I think I have a good respect for the power of rainfall, but if Brett has better info, I'd love to hear it!

[Justin_Zook]

Joe Hancock,

Haha,  sorry I should have used the term dead instead of brown.  Coming from a turfer, thats no good!!!  

Other than that, I love brown LIVING grass!


Justin Zook

[B. Mogg]

One thing I forgot is all that internal drainage work involved in making these flashed bunkers work in high rainfall conditions.

Well it needs to be done by hand, which in the US would drive costs up considerably. Here where labour costs are "ahem" somewhat lower, its no problem.

There is a cost/benefit point where further improvments in bunker design are not warrented against the infrequent cost of pushing the sand back up and the occasional re-build. All depends upon the frequency of the rainfall event and the expectations of the user/membership.

[BK]

The terrain in this part of the country is pretty hilly, so much so that you have to drive nearly 50 miles to reach a course that will reduce the number of sidehill, downhill, etc... lies you will get to less than 25 per round.

A local public(actually state park) course which is about 25 years old now, originally had these huge steep bunkers, with deep white sand on nearly every hole.  First decent rain, most of the sand ended up in the rough or fairway.  Several of those original traps have now become grass bunkers, obviously due to the poor design of them and lack of money for maintainence.  Those that remain are in perpetual state of repair, either washed out to the point that very little sand remains, (some are so hard you can putt out of em) or all the sand lies in the bottom and none on the facing.

Unfortunately the course hasn't the money nor the manpower to fix or maintain them properly.

Should they make them all grass or allow them to become waste areas that you want to avoid at all costs?  Other than the traps, this course is generally well maintained.

[texsport]

Patrick_Mucci
        I don't believe that the flashed up bunker style is used any more in areas like South Texas or Louisiana unless it's an architect unfamiliar with out soils.
        A lot of architects also use coarser river sand to help stabilize the bunkers. It's not as spectacular as white Florida sand but also cheaper because it's locally available.

Texport

[John_D._Bernhardt]

Well said Texsport. I can only think of one course that did not have its bunkers reworked/constructed within 2 years in this area that have any real slope to them. Yet, time and time again they try and fail. Fazio just put in 76 beautiful bunkers with great than 25 degree slope. They were washed out the day i was there after a 1/2 inch rain in 1.5 hours. The area gets 50 plus inches a year. However most of the rain is in winter and associated with fronts as opposed to the thunder storms we get down here with higher concentrations. I hope Ruston la is far enough north for them to work but i doubt it.

[Jeff_Brauer]

Brett,

When you mention hand labor to install the internal drainage, I assume you mean that it is difficult to trench mechanically way up a slope in a small bunker lobe unless the trencher knows all the moves from the Kama Sutra?

We have been able to get trenches near the top, but it does take some convincing that we are serious!

Tex,

I guess I better plan on lowering my bunkers on the new Lake Jackson course even lower than I planned.

[Mike_Young]

When you say poor bunker design it can be taken as poor technical design or poor choice of bunker style for the area in question.  I assume that many architects consider their bunker style a design trait and in many instances carry that wherever they go.  In doing so they can be indentified by their style but at the same time it may create different bunker maintenance situationsin different areas..  I have a course in Costa Rica that has gotten as much as 65 inches of rain in one weekend.  There is another course a few miles away that has flashed bunkers that wash constantly to the tune of a couple of $100000 maintenance per year.  We explained this to the owner and he allowed us to use a flat sand bunker with excessive internal drainage.  It gives our course a totally different look but it remains practical.  I am not to say which bunker style is correct.  Both were constructed properly.  Yet one might not work as well in this particular local.  I am sure that many owners in the past have wanted a certain style just for the contrast and later found it to be more maintenance than expected.  With the golf market as it is now, we may see a lot of the high maintenance bunkers change or disappear much as they did during the 30's.
I am of the opinion that grassy hollows are more of a hazard than modern bunkers but that they are still used for contrast more than anything.  Who knows. if golf had been cultivated in a climate other than linksland we might not even have bunkers.
Mike