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200901MHBy Mark Holden

Last October, I had the pleasure of attending the American Society of Landscape Architects’ convention in Philadelphia.  While there, I spent much of my time sitting in the WaterShapes booth in the exhibit hall and found myself fielding a surprising number of questions from landscape architects about aquatic safety – and particularly on the new federal regulations and standards having to do with entrapment prevention.  

At first, I thought it was strange that this was such a hot topic among landscape architects, who, as a rule, haven’t been all that involved in the technical details of pools and spas.  But before long, it occurred to me with some strength that more and more landscape architects are indeed becoming watershapers – and, more important, that they recognize a need for developing knowledge and new skills in doing so.  

In other words, safety is obviously an important part of watershaping:  As professionals new to the field, they recognize that they need to know all about it.

This experience in Philadelphia has since triggered new thinking on my part when it comes to what I teach student landscape architects in the classroom.  Safety has always been part of what I help them understand, but the questions that came at me from licensed, practicing landscape architects made it even clearer to me that aquatic safety in water is a complex set of topics, each of which needs to be covered in some detail and ultimately accommodated in watershape designs and plans.


As we all know, aquatic exercise and play are not, by nature, entirely safe activities.  While it is true that swimming may well be the healthiest of all forms of exercise, we accept the fact that immersion in water always presents elements of risk.

In examining those risks, it’s helpful to break them down into separate categories, specifically:  drownings, entrapments, diving accidents, slip/fall hazards, electrical shocks and infections.  Periodically, these become controversial, societal issues, as has recently been the case with suction entrapments and is often the case in times following outbreaks of viral and bacterial infections involving cryptosporidium, a waterborne agent that causes severe and sometimes fatal intestinal distress.

The emotional and social profiles of these hazards are often heightened by the fact that small children are frequently the victims in drowning and entrapment accidents and that the elderly often fall prey to waterborne infections.  The fact that these incidents are mostly preventable forces those involved in watershape design and construction to press forward constantly in seeking workable solutions and implementing preventative measure.  

The pool/spa industry has dealt with these issues for years now and continues to seek the right combinations of remedies.  Those outside that industry – meaning the large majority of landscape architects, for instance – are generally not so well schooled in these issues but do need to get up to speed quickly if their inclination to get involved in watershaping is to continue to grow.

I’m involved with the full range of safety-related issues on a couple levels:  I teach landscape architecture students in a university setting, but through my firm, Holdenwater (Fullerton, Calif.), I also deal with these issues daily in conducting safety inspection of commercial swimming pools (where we see a multitude of problems resulting from improper design and maintenance) and in working with pool contractors and landscape architects to make certain their plans pass legal tests set forth by federal, state, county and municipal regulations, codes and standards.

Unfortunately, what we see in many plans are dangerous design choices – sometimes by pool professionals but far more often by landscape architects who simply do not know any better.  When we encounter these problems, we do all we can to enlighten these professionals about exposing their clients and a watershape’s users to risk.

Frankly, I doubt that landscape architects and even most specialists in aquatic design will ever become fully aware of all pool and spa codes and standards:  These provisions are epic in scope and scale and derive from myriad sources.  Nonetheless, there are some crucial areas in which we all should be well informed.

Helpfully, these areas of concern are not entirely dependent on details pulled from codes, regulations, laws and standards:  In many cases, in fact, a commonsense appreciation of what is and is not dangerous is most of what anyone needs to create watershapes that are as safe as possible.

Let’s look at each of these classes of safety challenges in turn:

[ ]  Entrapment.  Within the past year, suction entrapment has become the most discussed of all safety issues related to pools and spas.  These accidents are statistically rare compared to some others, but they are so horrific and are so often fatal that they merit special attention.  

In WaterShapes’ November issue, my fellow “Currents” contributor Dave Peterson offered a comprehensive overview of the regulations, codes and standards aimed at preventing entrapment accidents (“Entrapment Meltdown,” p. 28), so I won’t dig in as deeply here as I otherwise might.  But do let me isolate a few key points here to make the discussion complete with respect to what I think watershape designers need to understand.

In essence, entrapment is caused when hydraulic systems run too fast relative to the equipment and the plumbing configuration.  What can a watershape designer or a landscape architect do to protect bathers from improper system configuration?  The first step, I think, has to do with placing conditions on builders of their projects to meet (and, whenever possible, to beat) the minimum safety requirements imposed by code.  

Landscape architects’ plans typically have detailed notes for irrigation- and drainage-system installers, and I think the same should go for pool contractors:  In other words, you should spell out various safety-related details, specifying, for example, the use of line velocities that will prevent suction entrapments.

It’s unfortunate that so many watershape builders ignore line-velocity issues and therefore create situations in which entrapment is a hazard, but that doesn’t mean designers can’t take control by requiring maximum flow rates of five feet per second in suction plumbing and seven feet per second for discharge plumbing.  I’d even go so far as to require flows of four feet per second on the suction side:  This would go a long way toward reducing concerns about “fast” systems.  

The same goes for drain grates.  Instead of letting contractors use any grate pulled off the truck, specify what you want or place a general restriction on what can be used by specifying something along the lines of “all suction devices shall operate at 75 percent of the testing-approved limits for said devices (that is, drain grates rated for 206 gpm shall never be used on any system operating at 154 gpm or more).”

I’d also suggest specifying split-suction suction drains separated by 48 inches or more.  Health department codes specify 36 inches, but why ride a thin code margin when the adding a bit of pipe is the only issue?  As I see it, entrapments are preventable if fundamental details of this sort are addressed by both designers and installers.

[ ]  Electrical Shock:  We all know that water is a highly efficient electrical conductor – and, as watershapers, that our man-made bodies of water are circulated and illuminated using electrical power.  As is the case with entrapment, when safety standards established for system design and construction are not met, the combination of electricity and water can become dangerous – and fatally so.

Unlike entrapment, however, electrical safety in watershapes is rarely discussed these days.  I think that’s a mistake:  After diving into too many pools for inspections and having seen far too many accidents-waiting-to-happen atrocities in pool construction related to electrical safety, I think more attention should be paid to these systems.

The most common problems I see are water in improperly sealed light niches and lights set up without ground-fault circuit interrupter (GFCI) protection.  I shudder to think about what might happen to people swimming in these bodies of water when the lights come on:  Frankly, I’m surprised electrical safety is not a more prominent issue than it appears to be.

Once again, designers need to be aware of and specify measures to be taken in construction to ensure project safety.  This means notes and specifications directing builders how to protect against electrocution; mandating the use of appropriate GFCIs; and requiring full and proper bonding and grounding of all metal components.

Complicating matters on this front is the fact that some products work only for limited amounts of time.  Most single-gang GFCI units, for example, require monthly testing that is seldom done – but if and when they fail, they bring risk to every bather who might use the watershape.  At a minimum, what designers can do is specify that all submerged lighting must be protected by a GFCI device and set baseline criteria for their selection, installation and, yes, testing.

Another possibility, of course, involves specification of fiberoptic or low-voltage LED lighting – a surefire means of avoiding electrocution hazards.

[ ]  Diving Injuries:  Although fewer and fewer watershapes are being designed with diving boards or diving wells these days, many of the landscape architects’ plans we see these days do include these features and seldom demonstrate that the designers are paying any attention to what happens to divers once they enter the water.  That’s not good, because diving accidents can result in severe head or neck injuries – and drowning is often a byproduct of these impacts.

In referring to this issue, I tell these professionals what I tell my students:  Forget the water when providing the physical form for a pool, spa or fountains, then imagine that you yourself need to get into that watershape, move around within it and even sit down if that’s what’s desired.  The exact same concept applies to diving:  If you think through where you’re locating a diving rock or board, then obvious issues arise if you’ve chosen to do so in an area that is shallow or has benches or steps.

Obstructions are obvious hazards to be avoided, as are the improper floor profiles that are often at the core of diving injuries.  In the former instances, common sense can be your guide; in the latter, there are minimum guidelines for the “diving envelope” for diving boards – recommendations that I always exceed.  My general rule:  If I plan on having people dive into a body of water, I make it deep, really deep, and make certain the diving area extends out far enough from the board that the possibility of contact between a diver and the pool’s floor is strictly limited.  

In public and commercial projects, diving-related signage is a critical component of any design or plan.  Public pools, for example, require signage alerting people to diving hazards, and many pools now instruct those using them that there is no diving allowed.  The warning is conveyed using marker tiles set around the perimeter of the pool or spa; this may not solve the problem, but at least those willing to read will have been warned.

[ ]  Water-Related Illness:  When the water in pools or spas is not properly treated or filtered, pathogens such as cryptosporidium, giardia, staphylococcus and legionella (among others) can infect bathers.  There’s a science to disinfecting water, and it’s challenging to watershapers because different organisms respond differently to various types of chemical treatment.  In fact, some of them have even developed immunities to approaches that had once been effective.

Watershape designers should all be aware that proper sanitization is critical in any body of water with which people might become involved – and that means just about every watershape, no matter where it’s built.  Fountains, for example, were once considered “safe” because they aren’t designed for direct human interaction, but in the real world it’s no longer fair (or smart) to assume any such exception.

There are many possibilities when it comes to water treatment, and watershape designers must define systems for all features with which people might come in contact.  That means demanding proper turnover rates for filtration and circulation – details that should be indicated in plan notes.  

I tell my students that there are five magic specifications that need to be included with all watershape designs:  pump, filter, sanitizer, auto-fill and overflow – basic, but a start.  Without all of these elements in place, you run the risk of exposing bathers to waterborne pathogens – something that should not be anyone’s goal.

[ ]  Slip/Fall Hazards:  According to the Federal Government, slip-and-fall injuries account for one in three of all non-fatal injuries.  Common sense tells us that water makes smooth surfaces slippery and increases the chance of someone falling and hurting him- or herself – a problem that can be exacerbated by the sometimes vigorous play in and around swimming pools.  

If someone slips and falls in a space you’ve designed and is badly injured, you can be held accountable in a court of law, especially if your design carries no apparent accommodation for good footing.  The solution is to mitigate your exposure to such liability by modifying your designs accordingly.  

Polished granite, for example, is beautiful and I love it in landscapes – but it may be the worst-ever material to use as coping around a fountain or pool.  Still, this material seems to be rising in popularity, so when it is unavoidable I advise my students to alter its surface in some way (that is, flame it or bush-hammer it) or replace it with another material around watershapes.  

We just worked on a fountain that presented just this risky use of granite.  We advised the landscape architect who designed the project to flame all the horizontal surfaces to add texture and slip resistance while maintaining the polished look on vertical surfaces.  

It’s incumbent on watershapers to be aware of the coefficients of friction of various surfacing materials and avoid those that present slip hazards – especially if those hazards increase when the material is wet.  This is such a key point that, on public projects, designers must prove to health departments and other agencies just how resistant various proposed materials are to slip/fall hazards.

[ ]  Accidental Drowning:  Deaths by drowning – particularly those involving young children – are among the highest-profile of all incidents related to watershapes.  Known as the “silent death” because children often fall into water with no audible splash or other sound, it is (according to the Centers for Disease Control) the second-most common cause of death among children aged one to four years.  In 2004, for example, 26 percent of all deaths of children in that age range were drowning incidents, with the vast majority of them taking place in backyard swimming pools.

This is another huge topic that could involve a discussion many times the length I’ve been given for this column.  Suffice it to say that watershape designers need to know that there are multiple measures available to them that are intended to prevent these incidents, including fences, safety covers, self-latching gates, door alarms and submersion-alarm systems, among others.

Most experts recommend using multiple “layers of protection” in homes with small children, and all press the fact that there is no substitute for constant parental supervision.  Different jurisdictions impose varying sets of requirements related to details such as fence heights, cover configurations and more, with most of the rules applying only to new pool and/or spa construction.

Watershape designers need to be aware both of the risks and of the need to seek solutions based on the conditions presented by a given project:  Simply put, what works in one setting may not be the right call for another, so research and careful, individualized consideration must be used to make given environments safer.  

From a design standpoint, the fundamental concept is to create a physical barrier of some sort that keeps unsupervised children from gaining access to the water.  At our firm, we’ve used fences, hardscape treatments and even landscaping to get the job done, all with an eye toward making whatever solution or solutions we choose to use as aesthetically pleasing as we can.  Electronic alarms are also a possibility:  When correctly installed and maintained, they offer an aesthetically neutral option.

As for physical barriers, there are lots available products that get the job done without being offensive to the eye.  There are lots of decorative fences out there as well as permanent hardscape structures that can also become part of a drowning-prevention strategy.  In some cases, pool covers can be used – our preference being, for appearance’s sake, to use models that have hidden tracks.


From top to bottom of this list of issues, it is fair to say that every watershape designer is responsible for seeing to it that their clients, guests and communities are provided with safe aquatic environments.    

Art and recreation should not pose threats to those who would enjoy them.  Making beauty safe requires creativity, technical savvy and situational awareness – and it all begins with a fundamental understanding of the nature of water and how human beings interact with it.


Mark Holden is a landscape architect and a landscape and pool contractor specializing in watershapes and their environments.  He has been designing and building watershapes for nearly two decades, and his firm, Holdenwater of Fullerton, Calif., assists other professionals with their projects.  He is also an instructor for the Genesis 3 schools and at California State Polytechnic University in Pomona.  He can be contacted at This email address is being protected from spambots. You need JavaScript enabled to view it..

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