The drainage solutions being used at Gleneagles

Alistair Dunsmuir
By Alistair Dunsmuir March 18, 2012 14:24

The drainage solutions being used at Gleneagles

It was in a crowded exhibition hall at Harrogate earlier this year when I ran into Steve Eaves, associate publisher of Greenkeeping and Golf Club Management magazines. He asked me if I could write an article on drainage and aeration. Having agreed to put pen to paper I was then left to ponder over what to write for the readers that they might find interesting, as I thought: ‘Haven’t we read all there is to read about these subjects before?’

Well at the risk of sounding like an ‘anorak’, I think there are some aspects of what is happening in the world of drainage and aeration here in the UK that are indeed ground-breaking and should therefore be of interest to those of you who like to hear news of what is going on at other courses.

Some may be aware that in early preparation for the 2014 Ryder Cup tournament, Gleneagles Hotel has embarked on design changes to holes 9, 10, 12 and 18 on the Jack Nicklaus-designed PGA Centenary Course, (involving the movement of over 35,000 tonnes of earth), and has also installed the SubAir system which will be used to improve the drainage and aeration of the greens.

The SubAir system is a motorised pressure devise which has been around for about 20 years but few courses in the UK have found the justification to install it. It is installed underground close to each green and attached to the drainage pipe outlet of a UGSA orCaliforniaspecification green whereby there is a perforated pipe system lying beneath the putting surface.

In the case of the PGA Centenary Course at Gleneagles (previously known as the Monarchs’ Course) the greens were built in the early 1990s to USGA specification and therefore the greens have the advantage of a combined perforated pipe and drainage carpet construction, which is ideal for the efficient operation of the SubAir system.

In ‘vacuum mode’, the SubAir system increases the rate of drainage on greens by lowering the pressure under the green which causes the green to drain quickly, drawing in air and oxygen from the surface behind the water.

The benefit of being able to increase the drainage performance at the ‘flick of a switch’ becomes apparent when one considers the effect of the horrendous downpour of rain at the 2010 Ryder Cup at Celtic Manor.

The improved drainage performance also provides the benefit of being able to improve the growing environment for the grass and roots well in advance of the big event. The tournament will be held at the end of September, and according to climate records, a monthly average rainfall of 59mm can be expected for that month, assuming it is close to the average.

Being able to control the soil / water / air ratio within the profile should also have an influence on the potential firmness of the greens.

When switched to ‘pressure mode’, the SubAir system can not only push air upwards through the rootzone, thus aerating the roots, but can also be used to adjust the temperature of the rootzone. In some states in America this feature is used to cool the greens and reduce the risk of heat stress, while in Scotland this feature will be used to warm the rootzone which will be of significant importance at the high latitude and high elevation of Gleneagles, which has a shorter growing season than most of the other golf courses in the UK. Daylight and sunshine hours in September will also be a lot less than in the south, further reducing the potential for growth and evapo-transpiration.

It was reported that golf courses and estate manager Scott Fenwick told The Scotsman newspaper that sensors had been placed in both the 10th and the 17th greens to compare the greens when the first machine was installed.

Scott reported: “When the machine first went in, the 10th green was one degree colder than the 17th and it was also five per cent wetter. It is now 1.2 degrees warmer than the 17th, and six per cent dryer.”

This is proof, if proof were needed, that an investment of around half a million pounds for all 18 greens could well be justified based on some measurable, scientific evidence and the knowledge that the drainage and aeration could be optimised with the upmost precision in the run-up to the Ryder Cup tournament, and far beyond into the future.

For a video showing how the system works in more detail, search for ‘How Does SubAir Work’ on YouTube.

While ‘big budget solutions’ of this scale are few and far between in the UK, most clubs will resort to managing the drainage and aeration of their turf in ways which give maximum results with the least disruption and at a price they can afford.

When it comes to aeration, this will generally involve ‘tine’ aeration, and any form of aeration that also ‘de-compacts’ the profile and improves soil conditions wins hands-over-fist compared to simply poking metal slit tines into the ground. The timing of when this work is carried out in the autumn / winter months should also be influenced by the soil condition, moisture content and the weather forecast, rather than the calendar, so that optimum results can be achieved and the ‘fissuring’ of the soil can be retained for as long as possible.

I think back to the days of when I was sent out almost on a weekly basis throughout the winter with a counter-weighed Cushman and a heavy slitter doing more harm than good on greens which became progressively more compacted by the weight of the machinery. My opinion therefore of the old fashioned ‘greens’ slitter’ (where aeration of compacted greens is concerned) is that the slitter would probably be of more value if sold as scrap metal, especially given the value of metal at today’s prices.

Subsequently, the invention of tractor-mounted aeration equipment such as the Verti-drain and Wiedenmann Terra Spike provided the ability to break up the soil and lift the profile, thus creating a better soil structure across the board as opposed to a hard soil profile with glazed holes in it. More recent innovations such as the Sisis Javelin AerAid and Imants GreenWave (among others) have enabled turf managers to achieve a much more uniformly aerated and de-compacted soil profile with an improved bulk density, which has so many benefits in terms of gas exchange, microbial activity, water penetration and drainage.

However, there seems to be little point in carrying out aeration just for the sake of it without clearly identifying what is going to be achieved in terms of benefit. If removal of thatch is an issue, then deciding whether to pursue a hollow-core aeration strategy or a deep scarification programme will largely depend on the extent of the thatch layer and the condition of the rootzone in the top 60mm to 75mm of the profile. Where ‘layering’ exists as a result of different top-dressing materials, the hollow-core approach will almost certainly have its merits and in an ideal world should be carried out in August if the golfing calendar can be arranged to accommodate the work – it is when ground conditions are firm and favourable and recovery is usually quick. August is also potentially the best time for improving the greens in terms of root growth if the greens are adequately fertilised (ahead of winter), and often coincides with the holiday period when course usage by members and societies can typically be much lower than the busy months of September and October.

After addressing issues near the surface by tackling thatch problems and soil layering issues, we can look for deeper problems such as black layer, dry patch and anaerobic conditions, all of which can be addressed with the punch-tine aeration systems which can reach between 125mm and 225mm deep. The use of 13mm tines at 50mm centres with five degrees of ‘heave’ typically used twice in November / December and again in January / February when the greens are firm will suffice for most greens, followed by hand mowing / rolling to smooth the surface, keeping the use of ride-on equipment on the greens to a minimum. Monthly aeration during the summer months is hugely beneficial for aiding water penetration and resilience, and can be carried out to great benefit using 8mm diameter pencil tines, 150mm deep, at either one or two inch centres, depending on ground conditions or the strength of the roots.

Where there are soft, wet areas and sub-surface drainage problems, an investigation of the profile and the levels will be able to determine how to improve the situation. Typically, this might include more drastic but effective techniques being used such as: ‘Drill n’ Fill’, deep air injection (for example all Terrain or Dagger), vertical drilling or the installation of a piped drain system by trenching or thrust-boring.

On a number of the older courses, one finds depressions on greens which trap the water and flood during heavy rainfall, thus jeopardising play. In cases such as these there are practical solutions that can be used which involve a relatively small amount of work and disruption.

At Tunberry Golf Club, Euan Grant has successfully carried out the Verti-Go vertical drilling system using Aquadyne vertical columns to drain a problem green down into the sandy soil deep below. The benefit of this drainage technique is the small amount of disruption and the speed at which the greens are back in play.

Where big depressions exist on old greens, a good solution can be the installation of a ‘plug-hole’ type drain which is lined with a hole-cup and connected to a piped exit drain. One such drain has recently been installed on the 18th green at Royal Guernsey where the exit drain was ‘Thrust-bored’ under the green, thus eliminating the need for a deep trench to be dug across the green. In addition, vertical holes one metre deep were also installed in the surrounding areas using a simple hand auger and backfilled with peas shingle to within 300mm of the surface. The benefit of this in-house project was that the green was playable the next day and there is no longer a need to push off any water. Maintenance equipment can now work on the green without fear of damaging the surface of the soil beneath.

Looking to the season ahead, any drainage problems that were noted over the recent winter months may well be best addressed in the coming summer or early autumn before ground conditions deteriorate again, as this will enable an on-going late-season aeration programme to be achieved as well.

Peter Jones MSc, MBPR, RIPTA is a former course manager and a current course consultant

Alistair Dunsmuir
By Alistair Dunsmuir March 18, 2012 14:24
Write a comment


  1. wyn thomas May 15, 19:13

    hi. found this article very interisting.

    Reply to this comment
  2. Bothwell Castle GC (@bcgolfclub) April 14, 15:09

    » The drainage solutions being used at Gleneagles

    Reply to this comment
  3. (@GCM_mag) (@GCM_mag) March 18, 14:25

    From Gleneagles to Royal Guernsey, we take a look at the drainage solutions different golf clubs are deploying

    Reply to this comment
View comments

Write a comment

Your e-mail address will not be published.
Required fields are marked*

Join Our Mailing List

Read the latest issues

Advertise With Us

To advertise in the magazine or online, contact:


Social media