Bunkers are often the scourge of amateur and professional golfers alike. Whilst their presence on the golf course is intended to both challenge and chastise, sometimes a wayward ball can be overly punished if the bunker in question suffers from poor drainage. Here, Peter Cullen, Technical Sales Manager at Tarmac’s Topsport team discusses the key issues around bunker drainage, and how greenkeepers can keep their bunkers in play for as long as possible.
Given the varying weather conditions the UK is subjected to, the issue of finding a robust and long-lasting solution to bunker drainage has so far proved difficult for greenkeepers across the country. Whilst a soak-away or adequate piped drainage system should be installed as part of any bunker construction, so too should some form of bunker lining.
Generally, a lining will improve sand retention, as well as both reduce the wash down of sand from bunker faces and migration of sand towards the green. They can also go a long way to reducing stone, silt and clay contamination, and generally contribute to lower levels of bunker maintenance.
However, many lining solutions have been tried and tested – ranging from subsoils or inverted turf bases, to spray-on, rubber crumb, or material linings – and finding one which offers reliable drainage and long-lasting performance without detracting from the course’s aesthetics, has been troubling greenkeepers for years.
Some ‘spray-on’ lining options have often been the go-to solutions for more established courses. However, this form of lining has a tendency to break-up after a number of years. Coupled with the fact that installation time is limited by ambient temperatures and can therefore only be installed from spring through to autumn – i.e. peak playing season – course managers often face a constant battle to manage bunker downtime with effective playability.
For those courses where maintenance budgets are limited, spray linings and the associated maintenance costs can prove to be problematic. Other methods adopted over the years include a simple system of a compacted subgrade overlaid with bunker sand. However, if not maintained on a daily basis the subgrade can quickly be raked to the surface, affecting playability and presenting a potential damage risk to players and their clubs. Using a physical liner sheet, such as a geotextile or polyurethane material, is a method greenkeepers on a budget have considered in the past. Whilst it offers a barrier between the aggregate and the sand, appearances can quickly deteriorate around the edges of the bunker with the lining becoming visible if poor maintenance practices are observed.
Ultimately, no real long-term lining method for effective drainage has been discovered which can stand the test of time without detracting from a golf course’s aesthetics.
However, with a view to tackling the varying problems posed by limited bunker lining options, Tarmac’s Topsport team worked closely with a number of the country’s leading greenkeepers to create a unique modified porous asphalt-based lining.
Given its simple structure, Topsport’s bunker lining avoids the use of chemicals – unlike spray linings – meaning it can be laid in nearly all weather conditions, typically during the quieter playing months or as part of winter course closures.
What’s more, there is no need for a type-1 aggregate layer to be included in the profile, provided the course subgrade is suitable. Given the product’s composition, it also presents no risk to either equipment or the player as the product will not degrade. If the correct depths of Topsport’s bunker lining and bunker sand are adhered to, and provided appropriate drainage is in place to ensure water is moved away from the bunker location, then it will drain effectively and eradicate the risk of ponding or a ball landing in standing water.
For clubs on a strict budget, the modified porous aggregate solution is simple enough to apply independently and a 100m2 bunker can be lined by a four-man team in just two hours – either directly from the delivery vehicle or from an aggregate hotbox, depending on the level of course access.
Finally, due to the improved drainage and subsequent reduction in standing water, a bunker’s sand retention rate is much higher, even on steeper faces, as the sand is far less likely to clump together. It will also mean less replacement sand is needed over the course of the year, further contributing to reduced maintenance costs.
One such club which has felt the benefit of the Topsport Bunker Lining is the Nick Faldo-designed Chart Hills, in Kent. Home to plenty of bunkers, including The Anaconda – the longest in Europe, the course’s greenkeepers faced a number of historic bunker maintenance issues.
“We suffer significant wash through heavy rain here at Chart Hills and we are also situated on heavy clay. However, the new lining has just improved the bunkers no end,” says Neil Lauder, Golf Course Manager at Chart Hills Golf Club.
“In terms of maintenance, before the lining we were spending probably sixty per cent of our resources on bunker maintenance. We are a high maintenance course and we’ve got a lot of bunkers, yet the ones that we’ve used the Topsport Bunker Lining in have proved to be absolutely remarkable, especially when it comes to holding sand on the high faces.”
In short, greenkeepers who have long troubled with poorly draining bunkers now have an alternative lining which can keep bunkers in play virtually all-year-round. Ultimately, golf is a game that can be played and enjoyed in most weather conditions, and being able to deliver a challenging course that is just as consistently playable on a hot afternoon in July as it is in a rainy morning in November, will go a long way to keeping both members and municipal customers happy.