Swimming ponds and dams are growing in popularity as a natural and eco-friendly alternative to traditional swimming pools. Resembling a small lake or wetland, natural swimming dams blend seamlessly into the landscape, enhancing the beauty of your property and making them a lot more appealing than concrete or tiled pools. Plus, unlike traditional pools which tend to follow standard shapes and designs, natural swimming ponds can be designed in various shapes and sizes, with added features like waterfalls, aquatic plants and shallow zones. You get the flexibility to excavate your pond to the exact size, shape and design you want.
Even better, unlike traditional pools that rely on chlorine and other chemicals, natural swimming ponds use biological filtration and beneficial bacteria to keep the water clean. This creates a healthier swimming environment by not exposing swimmers to harsh chemicals. And if they are set up the right way, with good biological filtration or aeration, natural swimming ponds require less upkeep and maintenance than traditional pools which quickly turn green when neglected.
Why use liner for a swimming pond or dam?
When constructing a swimming pond or dam, one crucial decision is whether to use a liner or leave the pond unlined. While the choice is yours, there are several benefits to using a liner.
Prevents water loss
One of the biggest challenges with an unlined pond is water seepage. Without a liner, water can drain into the surrounding soil, leading to fluctuating water levels and the need for constant refilling. Liners on the other hand, create a watertight barrier, maintaining consistent water levels and reducing the need for additional water input.
Prevents soil erosion
Liners also prevent erosion of banks which is a common problem in swimming ponds and dams which have a lot of traffic, especially when swimmers are getting in and out. It means you can maintain the original shape and design of your swimming dam for good. For instance, the steps or shelves you design in don’t wash away.
Safer and more comfortable for swimming
Another advantage to a liner is that you can protect swimmers’ feet from sharp rocks and uneven surfaces that can make swimming uncomfortable and even hazardous. The last thing you want is to build a swimming pond that people don’t feel comfortable swimming in.
Which liner should I choose?
Our recommendation is EPDM (Ethylene Propylene Diene Monomer) liner. EPDM is a synthetic rubber material known for its durability, flexibility, and resistance to UV rays, extreme temperatures and chemicals. It also looks great in the wild, holding its shape and look for decades.
Benefits of using EPDM liner for a swimming pond
Flexibility and durability
EPDM liners are highly flexible, allowing them to conform to irregular pond shapes and slopes. They are also resistant to punctures and tears, ensuring long-term performance.
UV and weather resistance
Swimming ponds are exposed to sunlight and changing weather conditions. EPDM liners are UV-resistant and can withstand temperature fluctuations without degrading. For instance, Rollgum liner is designed to maintain its look and quality in extreme temperatures ranging from below -40ºC to +150 ºC. This is not the case with plastic liners which become brittle in the cold and stretch in the heat.
Safe for fish, humans and the environment
Unlike plastic liners which leach harmful chemicals over time, high-quality EPDM liners are chemically inert and non-toxic which makes them safe for aquatic life and people.
Easy installation and repair
EPDM liners are available in large sheets and can be joined together easily. In case of damage, which is rare, they can also be easily repaired using EPDM patch kits, which reduces maintenance costs.
Considerations before using EPDM liner for a swimming pond
While EPDM is an excellent choice for lining your swimming pond or dam, there are a few things to consider before installing it.
Surface preparation
A smooth and stable base is essential to prevent damage to the liner. After excavating your pond, make sure to remove any rocks or sharp objects from the floor. We also recommend using a protective underlay, which shields the liner from sharp objects and root growth. If you have rocks or sharp objects on the pond floor that you want to keep, you can add underlay over the sharp object first, then a layer of EPDM liner, followed by another layer of underlay and then the final layer of EPDM liner.
Water filtration and circulation
Just because a swimming pond mimics a natural lake doesn’t mean it can’t benefit from aeration or a biological filter. Depending on the size of the body of water, you can add a biological filter such as Matala’s Biosteps filter for small ponds or an aeration system for larger ponds. Keep in mind if you use an aeration system, you don’t want power in the water, so we recommend a sub-surface aeration system rather than a surface aeration system. Sub-surface aerators have the motor compressor installed on the bank of the pond whereas surface aerators have the motor/compressor installed floating in the water.
Slippery surface
EPDM liners, like all liners, can be slippery when wet. This can make entry and exit points difficult to navigate. The good news as mentioned above is you can design your pond with this in mind and have your excavator build steps or shelves to allow for safe entry. Another option is adding refined sand, gravel or wooden platforms to entry points to improve accessibility. You can also consider anchoring a floating platform for easy access to deep water.
Aesthetics and edging
To achieve a natural look, you can also cover the liner edges with rocks, gravel or plants. This allows your liner to blend seamlessly into the natural landscape. We recommend digging a trench around the perimeter of the pond which you can lay the edges of the liner in and fill with dirt. That way the liner is secured in place and looks neat on completion.
How to install an EPDM liner for a swimming pond
1. Excavate the pond shape: Plan for separate zones for swimming and filtration or aeration.
2. Lay a protective underlay: Remove any rocks or sharp objects and use a pond liner underlay to prevent punctures.
3. Install the EPDM liner: Ensure it fully covers the pond with extra overlap for securing the edges.
4. Add water: Fill the pond with water or wait for rain to do it naturally.
5. Add a filter or aerator: Install your biofilter or aerator to maintain water quality.
6. [Optional] Plant out your banks: For an extra natural touch you can plant out the banks with native vegetation or add decking.
Need help or advice?
Thinking of building your own natural swimming pond? We are happy to provide general advice or the materials to do it, e.g. EPDM liner, biofilters and aerators. Our advice is FREE and no-obligation. Get in touch with us.