As many engaged in golf course maintenance will know, the margin where water meets grass can create many challenges.
The engineering factors and constraints of water margins are complex. Things to consider include foundation design, hydraulic loading, flow velocity, erosion potential, imposed loads, construction and environmental hazards, and health and safety issues.
Natural water margins are important ecological habitats. Unmanaged, these shallow areas support emergent vegetation, which in turn provides cover for threatened species, such as amphibians and water voles. However, when these areas impinge close to areas of play on golf courses, problems arise.
Banks can erode and adjacent high footfall areas can become slippery and dangerous for golfers and staff. When access to these areas is difficult for a golf club’s maintenance team, they can also become unsightly.
There’s also the rules issue. It can often be difficult to determine what is in or out of a hazard. The result can often be a proliferation of red and yellow stakes, which in my opinion are very unattractive.
My company’s primary focus has historically been on bunker edges – that troublesome zone where sand meets grass. Our solution there is to stack layers of artificial grass tiles to form a synthetic, low maintenance, natural-looking buffer between the sand and grass.
We have now adapted this approach to provide a solution to the challenges provided by water margins. Our AquaEdge product is a retaining wall comprised of horizontal layers of sand-filled synthetic grass.
AquaEdge offers the opportunity to have consistent and cleanly defined water margins, close to areas in play, that look entirely natural, and, further away from play, can blend into areas with vegetation that can continue to provide ecological habitat.
The installation work is very fast and involves minimal disruption when compared with more traditional retaining solutions. The maintenance of these areas is considerably reduced, and the debate of whether a ball is on or out of a hazard becomes a thing of the past.
We approach water margin projects using a civil engineering process, which includes an initial investigation, design and specification work, planning, the supply of the various components and installation.
Some golf clubs are now beginning to recognise the potential for using stacked synthetic sod as a lake edging.
I had wanted to apply my invention to this use for several years, but with my focus very much on golf bunkers, the opportunity didn’t arise, despite a few overtures. It was therefore a great thrill when one of the UK’s most prestigious clubs invited me, and I am very grateful for their support.
The design brief was to provide 150 metres of lake edging, in our synthetic revetted style, and extending on average 200mm above the permanent water level. This might sound simple, but the lake water level could not be lowered, the available time window was very short and no heavy construction machinery was permitted.
We were granted the opportunity of a small-scale trial installation. This enabled us to gain a vital understanding of the lake bed profile, ground conditions and build speed. As a result, we decided that the working area had to be de-watered, and selected a specialist demountable cofferdam with over-pumping – one of only two in the UK. This enabled our team to build the AquaEdge wall in three sections.
Following a successful installation, we were called back in October 2016 to build another lake edge of a similar scale.
We have had very positive feedback from both the club and the managing director of the cofferdam provider. He said: “In my opinion, for a low water edge solution, AquaEdge is the best process that we have seen. It is much faster and less labour intensive than all other methods, plus the end aesthetics are stunning.”
While our focus at EcoBunker has been on our bunkering products, the outlook for our water margin product looks very positive. Our next project, at Cabo San Lucas in Mexico we see us building the edge of an island green using the same approach that we introduced on our UK client’s golf course.
Richard Allen is a civil engineer, inventor and CEO of EcoBunker
This article first appeared in issue 49 of Golf Course Architecture