There are plenty of materials available to line artificial lakes for cable wakeboard parks. The primary types are natural, compressed materials like clay or bentonite, hard surfaces like concrete, or flexible liners called geomembranes.
Clay Liners
It's tempting to gravitate towards clay (bentonite) liners since "natural" solutions are widely considered environmentally friendly and sustainable. In truth, there are several significant issues with clay. Depending on the underlying soil type, it can take a tremendous amount of bentonite to seal even a small pond. Generally, the bentonite layer needs to be thick (as much as 12" on every surface) to ensure a reliable, durable seal. In that case, the pond volume will be significantly reduced and must be enlarged to maintain a functional size. Installers must tightly compress bentonite and other clay materials to achieve a somewhat watertight seal while maintaining a specific moisture content throughout the process, or the clay will not bond. These requirements can make installation troublesome, time-consuming, and expensive. Even after installation, a clay liner must remain wet for the lifetime of the lake. Drying out renders the clay just so much dirt, subject to cracking, crumbling, leaks, and erosion.
Rigid Liners
Imagining a concrete liner for your lake evokes that characteristic aquamarine color and sharp, chemical smell of your neighborhood swimming pool. It might seem like a natural choice for your artificial lake, especially if your focus is on keeping the lake clean, clear, and free of pathogens. However, some downsides to consider are the time and expense of installing such a large expanse of concrete, the number of pumps, drains, and piping required, and the daily chemical load. Chlorine and other pool chemicals can irritate your guests' skin and nasal membranes, and well, it just doesn't feel like wakeboarding if you're in a swimming pool.
Nature can create even more significant problems for a rigid liner like concrete. Whatever your climate, soil movement triggered by relatively small changes in temperature and moisture content can generate tiny, invisible cracks in your cement liner. Other uncontrollable phenomena like earthquakes or tremors, nearby lightning strikes, or even nearby construction can cause extensive, immediately visible cracks or tiny, invisible but costly leaks over time.
Flexible Liners
Flexible liners offer the highest level of impermeability in a real-world application. They're far more waterproof than any natural liner materials and provide better seepage control to prevent both the loss and incursion of outside water and impurities. Clay liners only offer limited impermeability, which drops as the material ages and develops leaks. Flexible liners aren't brittle in the same way hard surfaces are and can easily handle soil expansion and other small movements without cracks or tears. High-quality geotextiles can even last decades in these situations without developing leaks. That means there's far lower maintenance and repair costs and substantially less water loss over the lifespan of the lake.
Repairs and Replacements
Bentonite and other clay materials, blended with the soil, will naturally settle over time. You'll need to add new clay lining material anywhere from every two to 10 years, depending on the amount you add and the activity in your lake. Flexible liners can last decades when properly maintained. The additional cost of replacing natural liner materials every few years makes them more expensive in the long run than flexible geomembranes. Owners can add clay without draining the water, but this is often time-consuming and can take days to weeks before the lake is clear again. Replacing a flexible membrane does require draining the lake (or portions of it) but is needed much less frequently and can be completed in a few days, and since there's no drying time (as for concrete), it permits immediate refilling.
Reduced Leakage
Clay liners are notorious for randomly developing leaks after installation. Some leaks begin immediately after filling the lake, while others take years to appear. Since tracing these leaks to a specific crack or thin layer of clay is nearly impossible, it's very tricky to seal the source of water loss. Failure to trace and repair a seemingly minor leak can lead to soil destabilization and even sinkholes over time -- especially in loose soils. Most lake owners with natural clay liners must dump the same amount of clay they initially used to establish a new layer. Bentonite, in particular, is often marketed as a self-healing material, but that's only true when there are nearly three feet of clay applied evenly to every underwater surface. This amount of clay comes with a hefty price in labor, materials, and transportation and significantly reduces the actual volume of the lake.
Easier Cleaning and Dredging
It's challenging to dredge or clean a naturally lined pond or lake because there is no distinct separation between the liner and the soil below. When removing the leaf litter and other debris that has broken down into sludge at the bottom, it's all too easy to scrape away the clay liner as well. Accidentally breaking the liner in this fashion inevitably leads to leaks that are hard to find and seal. In contrast, flexible liners are much more damage-resistant and easier to clean, making them a better choice for fishponds and recreation lakes alike.
Bank Stabilization
Clay liners are impractical for use near or above the water's surface since all the material must be kept continuously moist. Even temporarily, if the clay or bentonite dries out, it will become brittle, and then crumble or crack. A liner in poor condition makes the banks of a naturally lined pond much more susceptible to erosion and further damage. Flexible pond liners extend over the apron and banks of the pond, creating a single plane that protects every surface from soil loss and the threat of bank collapse.
Even with this protection, you'll want to reinforce the banks of your lake. If your guests can exit the water at any point after a wipeout, you'll need to ensure the entire perimeter of the lake is lined with rock or a thick layer of sand to guard against liner movement. Another option is to set up specific exit points at regular intervals, much like stairs on a traditional pool, which reduces the amount of work needed to reinforce the entire bank. It also widens your aesthetic options without the worry of constant foot traffic through your begonias.
What Kind of Flexible Liner?
Even after you settle on a flexible lake liner, you still have many options to choose from for your wakeboarding facility. Flexible liners vary in price, quality, flexibility, installation complexity, and overall lifespan. Some liners are better for cold environments where low temperatures make plastics brittle, while others can withstand intense daily sun exposure for years without breaking down.
Durability
When selecting which liner to use, consider how long you intend to keep the lake (i.e., operate the business). Will you be able to shield the liner from UV rays? How low are the winter temperatures in your area? How durable does your lake need to be, especially with regards to potential leaks? Actually, durability is the most critical factor to consider in making your design choice. Punctures and tears can quickly empty your pond. An installation like a cable park demands the highest level of durability in all areas. Fortunately, pond liner materials have expanded in recent decades, and current popular options include PVC, EPDM, HDPE, and RPE.
PVC stands for Polyvinyl Chloride and is an older, inexpensive option, at least in the beginning. PVC is flexible and relatively light, but it is not a long-lasting liner and is exceptionally vulnerable to tears. PVC is so susceptible to damage from sunlight and weather that it must be buried under at least 12" of soil. Even so, PVC has short warranties. Most types of PVC have plasticizers, fungicides, and other treatments that render them toxic to fish and plants. Clearly, for a long-term installation like a cable park, PVC isn't a practical choice.
EPDM is a form of synthetic rubber, and while it's fish-safe and flexible, it's both the heaviest and most vulnerable to punctures. Due to EPDM's weight, it ships in multiple narrow panels, which are clumsy to work with and must be joined with tape on-site, a tedious manual process that's prone to leaks from weak or poorly taped seams.
HDPE (High-Density Polyethylene) is a newer product that is both stronger and more resistant to UV rays than either of the two previous options, plus it's fishsafe. It's still heavy, but it folds nicely, and installers can join the panels on-site using a welder that forms a permanent bond. This kind of bond is less susceptible to leaks than taped or glued seams. HDPE is an excellent choice, yet BTL Liners offers a newer product that offers even more advantages for the high demands of a cable park.
RPE (Reinforced Polyethylene) uses a tightly woven reinforcing scrim sandwiched between other layers of HDPE and LDPE that offer additional protection against punctures or tears as well as exceptional UV resistance. In fact, RPE is so durable that other materials must be twice as thick to offer the same level of protection, making them substantially more expensive to purchase, ship, and install. Compared to other options, RPE is light, flexible, and easy to work with. Even better, if you need extra-large panels for an expansive lake, they can be joined at the factory using the highest quality welders, which reduces or eliminates the need to do manual seams on-site. Certain RPE products from BTL offer a 40-year warranty (more than twice the length of the next competitor), even when fully exposed to the sun. BTL's AquaArmor products are certified to contain potable water (drinking water for humans), representing an excellent seal of quality for your recreational lake.
It's imperative to use a highly durable RPE liner in the case of a swimming lake or pond (or a wakeboard park). Fish and plants don't jump and splash around the way people do, and a liner that's perfectly adequate for a peaceful fishing hole can't withstand the level of wear and tear found in your facility. Fortunately, moving up to a thicker number of mils isn't your only option. Using a multi-layered, reinforced RPE gives you a durable liner that's resistant to tearing yet still thin, flexible, and surprisingly light.
UV Resistance
Resistance to sunlight is much more important than you might realize. Sunlight and UV rays travel through water, and although their strength diminishes with depth, the effect still adds up over the years. PVC is the most vulnerable of the usual liner options, and it must be buried under a full 12 inches of soil to prevent degradation from UV rays. EPDM is more resistant than PVC but is not rated for total sun exposure, meaning your warranty is void if any portion of the liner is exposed, whether by design or accident. RPE is the most UV-resistant material by far and is available from BTL with warranties of up to 40 years, even exposed.
Installation
Installation for PVC is relatively simple. It's lightweight and folds easily to fit into tight corners, but if any seams are necessary, you must glue them as you work, making installation tedious and prone to flaws. EPDM is very flexible and can easily conform to the shape of your pond, but it's cumbersome, and you must tape the relatively narrow sheets together as you lay them to reduce the risk of tearing from sheer weight. The narrower your panels are, the more seams you must add, even though glued and taped seams added on-site are most vulnerable to weakness and eventual leaks.
RPE is about ⅓ the weight of EPDM and comes in enormous sheets that require seaming on-site only for vast projects. In those cases, seams are fusion welded, just like in the factory, which provides a highly secure, permanent bond that cannot degrade or weaken over time.
Safety
Inexpensive PVC liners are well known and widely available. Still, they're not a good choice for features that will involve human (or even fish and plant) interaction since they can leach toxic plasticizers such as BPA into the water. BTL's RPE and PPL polyethylene products are potable NSF-61 certified, which means our liners are approved to hold drinking water intended for human consumption. Using these liners, you'll never have to worry about harmful additives leaching into your lake environment and harming your staff or guests.
Underlayments
You must install geotextile underlayment (essentially a cushioning material) with many types of flexible liners to perform reliably and maintain the warranty. Here at BTL, we are happy to offer our professional advice on whether or not your project would benefit from underlayment.
What Makes BTL's AquaArmor Liners the Best in the Industry?
BTL’s experts are industry thought leaders and have long been authorities on the most popular liner materials for artificial lakes and ponds. Our team understands that choosing a liner for your new lake is one of the most important considerations you will make as you develop your project. If you opt for a low-quality liner, you risk punctures from nearby roots and rocks, rapid deterioration, and even toxicity.
BTL's AquaArmor line was developed specifically for water containment in everything from backyard fishponds, to naturalized artificial swimming holes, to enormous irrigation reservoirs. AquaArmor offers superior attributes and better value compared to any other geomembrane product for this kind of application. AquaArmor is less expensive, dramatically lighter, and available in much larger factory panels than the competition. Larger panels mean fewer seams, simplified installation, and a much lower risk of leaks. AquaArmor's NSF-61 potable grade rating ensures that you're using the safest materials on the market and eliminates concerns about unwanted chemicals leaching into the water and harming your staff or guests.
Pricing is a significant consideration for a new business venture like a cable wakeboard park. It can be tempting to scrimp on some invisible parts, especially those that are literally underwater. However, when evaluating the cost of RPE to cheaper materials, it's essential to recall that RPE is so durable against punctures, tears, general wear, and UV exposure that other materials must be twice as thick as RPE to offer the same level of protection. Try comparing the cost of a 45 mil EPDM liner (including the required underlayment, shipping, and installation) to the price of a 25 or 30 mil RPE liner from BTL. In the end, it's clear that compared to other options, RPE is the superior choice.
BTL's Reinforced Polyethylene Liners Are:
- One third the weight of other liner types
- Can be fabricated to your specific dimensions
- Easy to install and does not always require an underlayment
- Strong and puncture-resistant
- Easily welded together with heat
- Certified for potable water
- Available in larger sheets than many others liner materials
- Resistant to tears
- Resistant to UV exposure
- Able to handle rough soil and less-than-perfect support
- Simply the Best Liners on the Market
Is a Fully Lined Lake Feasible?
While there's no question that it's realistic to line a backyard pond with a geomembrane, many landowners and project managers assume it would be impractical to do for a large installation. Fortunately, manufacturers like BTL Liners can produce custom fabricated liners with minimal seams even when you're covering dozens of acres. Our expert team can consult with you or even assist in specific complex installation projects. BTL's experienced team has installed liners for projects as large as 40 acres in a matter of days. That's an impressive feat, but more importantly, it's a valuable addition that extends the lifespan of the lake and reduces maintenance requirements.
BTL Liners has lined thousands of artificial lakes and reservoirs with a wide range of specialized products, including RPE liners for cable parks like Wake Nation in Cincinnati, OH; Velocity Island Park in Woodland, CA; and more recently, a cable wake park in the Dominican Republic. With the sport's growing popularity, installing a high-quality product like BTL's AquaArmor liners is crucial for a competitive edge and the best guest experience possible.
How are BTL Liners Installed?
RPE liners from BTL are incredibly lightweight and flexible so that installation can be essentially a manual process, even on extensive projects. BTL provides experienced installation specialists to fit your needs. Our BTL crew regularly installs ten to fifteen thousand square foot panels manually, with six or fewer workers. When the panel sizes are 20,000 square feet or more, it is typical to use a beam and spreader bar to lift the roll with a backhoe or other equipment to unroll it. For these large jobs, it is appropriate to have 8 to 10 or more laborers to spread the liner. Once the panels are in position, one or two technicians can complete the field welding.
Installation instructions are surprisingly easy to follow. The liner roll has arrows indicating the length, width, and direction for unrolling. Step one is to unroll the liner in the direction indicated by the first number and arrow. Once the liner is completely unrolled, the second number indicates which way to unfold it. Typically, a liner can be placed on any "corner" outside of the excavation and unrolled as indicated. In your case, the choice of starting corner is determined by wind direction, obstructions present, available room to unroll the liner, etc. BTL packs its liners to give you the maximum flexibility in accommodating these variables.
The time involved in installing a liner from BTL will vary according to many factors, including the complexity of the job, weather conditions, size of the installation crew, etc. It's not at all unusual to manage over 200,000 SF per day, using backhoes and a team of 16 to 20. In fact, with sound equipment and a motivated crew, BTL has successfully installed over 400,000 SF (more than 9 acres) in a single day. Regardless of the size of your lake, lining it should require less time than any other option.
Overlayment
A certain kind of overlayment is becoming increasingly popular, and while BTL doesn't require it, they're happy to offer it as an option during installation.
It's clear from experience that any form of physical damage (from deer, kids with rocks, mechanical equipment, UV degradation, etc.) is by far most likely to occur on the upper edges of the liner, not out in the depths of the lake. Adding an optional "ribbon" of geotextile overlayment adds protection in these vulnerable spots. This ribbon also provides an added degree of safety. The upper edges are less slippery, so unobservant kids, dogs, deer, etc., can get out with less difficulty. So, while not necessary, this option is a relatively cheap form of practical insurance.
This ribbon is typically 8 oz. per square yard non-woven needle-punched polypropylene (or "geo," for obvious reasons). Geo is installed over the liner along the shore's upper perimeter and keyed into the anchor trench along with the liner itself. It's usually the roll width of either 12.5 or 15 feet. Before filling the lake, a small amount of fill must be placed over the entire ribbon so that it's not prone to float. For example, you may choose to install layers of smooth stones or relatively flat river rocks over your ribbon and liner to resemble a natural pond bottom environment. This attractive treatment will keep your ribbon anchored and provide a natural look without risking seepage or water loss.
Anchoring
Anchoring is the process of making sure your liner won't slip, move, flap around or allow water to escape your lake. It protects the edges of your liner from wear, tear, and exposure to sunlight and will enable you to move around the borders of your lake without damaging it.
There are several reliable methods for anchoring your liner, and the best ones fall into the "anchor trench" category. Typically, a basic anchor trench is about 12" wide and deep. However, it can be larger as circumstances demand. The larger but simpler "anchor shelf" variation is usually more suitable for lakes and most large installations. Rather than digging an actual trench, the shelf is a flat horizontal (or slightly canted backward) area about 4' wide. The liner is laid across the shelf then buried under an attractive fill material (clean sand or gravel, for example, if you're going for clear, algae-free water). This method also permits the installation of a protective geotextile ribbon.
Conclusion
Cable wakeboarding parks are popular, accessible venues that lower the bar for participating in a whole menu of water sports. Entrepreneurs can construct these parks on suitable natural or custom-built lakes, placed in an ideal location and built from the ground up for easy maintenance and just the right look. Artificial lakes have many advantages, and you can design them to blend into the existing landscape or present a clear, pristine picture that guarantees no slimy mud between your toes.
BTL Liners' strong, durable, and lightweight RPE products offer cost-effective, easy-to-maintain liner options for your artificial lake. Their advantages make them the obvious choice for price, ease of installation, and long-term durability. Think about it: your cable wakeboard park dream will still be going strong in 40 years. Shouldn't your lake be too?
