Drainage is underrated!

[Tom Doak]

Tom P:  As Jim Haley alluded, there is underground drainage in all those pockets at Pacific Dunes.  But on the ones in the fairways or in-play areas, instead of putting a cap on them which your ball would roll on top of, we buried them in the sand and are relying on capillary pull to keep puddles from forming.  We figured they could always pull up the drains and put those pretty plastic caps on some of them IF THEY HAD TO.

(You saw the one on the walkway because it's not in play, so we just put a cap on it.)

I haven't been to Pacific Dunes since February, so I don't know if they've done some of this or not ... probably some but not a lot.  I'll be back there in two weeks and will be glad to report back.

P.S.  This wasn't an entirely original idea ... Kingsbarns has the same drainage system, which they in fact borrowed from the drainage system that was put in on The Old Course at St. Andrews a few years ago.  Dave Wilber suggested the hidden drains at Pacific Dunes when Jim Urbina and I were lamenting the idea of drain caps.

[Derek_L]

Good evening to all,

From the engineers point of view I have to keep the best interest of the natural resources at hand, such as what will happen to the existing properties now that land development has occurred.  Basically what I look for when an architect has me review his plan is this:  I don't like to see hydrology areas crossing critical paths, what I mean by this is taking more of a watershed into an area (i.e. natural wetland, etc.) than what originally went to it.  Now alot of times things will work out just because a good stand of grass absorbs alot more water than tilled ground like corn fields with very little vegetation, but occasionally I get to spend lots of time designing structures that hold back water some as it leaves a wetland.  Something I like to do when mitigating for wetlands is to direct pipe outlets into different areas of the newly created wetland to get more water into it.  One obvious trick is to have pipes, if possible or feasable coming into different locations of an open water wetland/pond in order to move the water around some so you don't get a stagnant mucky eyesore.  I also like to look for something known as "short circuiting" with ponds.  Basically, this may occur if you have a stream or creek coming into a water body nearest the point of where the water body exits to another water body (the majority of the water body is upstream of the creek), this may over time cause erosion problems and skunky water surfaces. For the most part architects know what they are doing, as they have been doing it for a while.  However, every once in a while you get a course built and the ponds have no outlets thus rising higher than heck and encroaching on bunkers, greens etc.  I know that bunkers and greens look nice as they are close to water so they appear to blend into the water, but I would think when your bunkers or greens end up under water for short periods of time over and over again you may end decreasing the life of the feature.  My advice is to always have some sort of overflow or outlet area.  I also look at each pipe outlet and analyze the floe velocity to ensire that erosion won't occur, not only for the sake of a wetland or pond but also for maintenance reasons.  For the most part when I review drainage plans or design some of the drainage I always keep in mind how the course will be effected. As a golfer I hate to see catch basins, especially where the slope is so extreme that my ball is funneled into them to only come to rest on a rock hard grate.  I too like the idea of the drains that were used on some of Tom Doaks courses, as long as you have the right texture sand that is fine enough to allow water to pass through it in a readily manner, the water should always flow through the ground.  I never thought of it until now, but a product that the company I work for uses can be mixed into soil and increase the strength of the soil and open the roots up to allow more water to infiltrate into the soil, I have heard extreme numbers on the side of 16in/hr of percolation.  For an insitu clay soil this product can allow 3.5in/hr or so of percolation.  Interesting idea now that I think of it, but expensive.  This stuff works great and gets the water to infiltrate into the ground or into a perforated pipe, either way it works and usually results in very little water actually ever entering the pipe. Any questions about it just ask. Just alittle tip from the sportsfield industry, never use socks on perforated pipes as they clog up over time, always lay them in pea stone.

[Steve Lang]

Good post..

And make sure the spec says "washed pea stone or gravel"

[Tom Doak]

I just got back from a long walk around Pacific Dunes with Ken Nice.  (He has it in top-ten condition right now, by the way.)

Our drainage system is working quite well, despite the earlier post.  A couple of the buried drains worked TOO well, and sucked some of the sand down the pipe through the gravel, so he's had to replace those with caps as a temporary solution.  But there are only three more drain caps than when Tom Paul couldn't find any, and there's not a puddle to be found.

I love sand!!!

[Stephen Lang]

Tom Doak,  Would you put a foot of sand under an entire golf course ala Nicklaus, or just in specific drainage areas?  

Any opinion on how much a continuous sand base would add to the overall cost, percentage wise?

[Derek_L]

Steve,

I am going to go out on a limb and say that this scenario does not happen too much, but let's say (tell me if I am wrong with my calculations here) this course was in Minnesota, your'e looking at about 100 acres of actual golf course turf, fairways, roughs, bunkers, greens, etc. (100 acres is just for a number to estimate by).  A foot of sand over 100 acres is approximately 161,500 cy, now if the guy wants the job bad he can get the sand for maybe $2.00-$5.00 yd, for river sand, providing the USACOE will permit this much sand at one time, and ends up placing it for maybe $5.00-$10.00 yd, so now you are looking at $7.00-$15.00/yd and probably alittle higher, but 161,500 cy * $15.00/yd = $2,425,000.  Now Steve remember in an ideal situation the heavy earth contractor, depending on how close the sand source is could probably get the material for "dirt" cheap, it ends up being the placement costs that get expensive, in my experience anyways.  Hope that helps.

[B. Mogg]

We often put a foot (or more) of sand over a golf course. usually it's just fairways and part of roughs, but sometimes its the whole course. Makes for a clean site once the sands down and spread.

You are talking about 100,000 to 150,000m3 of sand, price is specific to location (here it's around US$14/m3, barged in). Once you put sand down over a clay base you are also going to add dramatically to the subsoil drainage required.....in a high rainfall location you are probably talking about 30,000 to 50,000lm of subsoil pipe.

On a % basis I would say adding this type of sand to a golf course adds about 20-25% to the overall cost.

[Stephen Lang]

Derek & Bmogg,

Thanks for reference numbers.  

I'm aware that Nicklaus has done this sort of thing in New Orleans and elsewhere, and recently in the Woodlands at Carlton Woods, which has gotten some rave reviews.  When we toured it during construction, there seemed to be some rather obvious "control" problems with sand depth and some washouts.

Next Questions

1) I wonder how this design approach fares in the long term with fines moving to and into the subsoil piping.  

2) Is the piping wrapped with a geo-textile or placed in a pea gravel filled trench drain network created under the whole areas like under sand traps?  
 

[B. Mogg]

Fines - long term I dont know - however you need to be rigourous in your testing of the sand before and during delivery (we feild check at random). We also ensure that sand has very little in way of fines. Our climate here is very high rainfall, high volume rain events so the perc rates of sand as tested is usually over 80 inches per hour (maybe over 100). Long term this probably drops down to 30 inches or less.

Geotextiles - no too many bad experiences in wrapping pipes or putting geotexitles between the gravel and sand. We have used geotextiles under the sand and drainage however.

Regarding sand depths - if coverage is only 6inches or so of course depth control will be an issue (spreading by bulldozer after all). But once you are over a foot, even allowing for say 2-4 inches of variance, there should be no problems in spreading the sand.

Brett