Waterscaping: A guide to Natural Swimming Pools

Natural swimming pools, or ‘swimming ponds’, are increasingly sought as an organic and ecologically conscious alternative to traditional swimming pools. These inviting aquatic features can transform gardens into tranquil oases that promote outdoor wellness and enhance biodiversity.

After working on some recent outdoor sauna projects with integrated natural water features, we feel that natural pools and swimming ponds provide the ultimate counterpart to outdoor saunas. So, we decided to find out more from some of the UK’s experts…

What is a swimming pond?

Swimming ponds, or natural swimming pools, combine the aesthetic appeal and ecological benefits of a pond with the functionality of a traditional swimming pool. While the terms ‘swimming pond’ and ‘natural swimming pool’ are sometimes used interchangeably, usually the former refers to a more naturalistic water feature with organic basin materials like clay or gravel, whereas the latter typically involves a more structured design with a concrete basin. Unlike conventional pools that rely on chemicals for water purification, natural swimming pools use aquatic plants and biological filtration systems to maintain clear and hygienic water. This creates a natural and harmonious swimming experience akin to wild swimming in a mountain lake. As a leading swimming pond provider, Gartenart, explains,

“Clear, clean water is the naturally occurring state in low-nutrient ponds and lakes if the body of water is large and deep enough. Swimming ponds are purposely built to emulate this state and are a prime example of how we can harness nature's intelligence effectively. A conventional swimming pool uses chemicals to kill microorganisms in the water, such as phytoplankton and bacteria. However, this isn’t necessary in a natural pool where the cleaning work is carried out by micro-organisms which exist together in equilibrium. This is the basic principle of a swimming pond - to use the natural purifying properties of plants and micro-organisms to sustain clean, clear and healthy water.” - Gartenart

Achieving crystal clear, clean water isn’t always only up to micro-organisms - submerged pumps and careful marginal planting are also often a key part of the science of swimming ponds. Hannah from award-swimming Swimming Pond creators, Ellicar, explains,

"A natural pool or swimming pond is a swimming pool that's filtered and purified hydrobotanically by water plants and a biological filtration system. That means clear, hygienic, living water without the need for chemicals. Native aquatic plants grow in the pool’s regeneration zones, absorbing nutrients and helping keep the water balanced and the algae at bay. Ultra-quiet, submerged pumps and a hidden hydraulic system circulate the water through the filters without the need for a plant room. The result is a balanced, natural-looking pool with water that feels like wild swimming in a mountain lake: soft, sparkling and rejuvenating." - Hannah, Ellicar

Health and Environmental Benefits

With natural swimming pools, it is possible to accomplish the best of both worlds—enhancing personal health and supporting wildlife biodiversity. Over the last two decades, the UK has experienced a resurgence in wild swimming, influenced by a growing desire to reconnect with nature and the evocative narratives found in literature such as Roger Deakin's seminal book ‘Waterlog: A Swimmer's Journey Through Britain.’ This movement has inspired many to bring the ethos of wild swimming into their gardens with natural swimming pools that offer a sanctuary for people and wildlife alike.

Although the deep part of the pool is generally reserved for human enjoyment, the carefully planted edges of the pond can support a host of wildlife, from pollinators to amphibians and birds.

"Wildlife starts to appear almost immediately after the pool is filled and the regeneration zone is planted. Diving beetles, pond skaters, and dragonflies are often the first to arrive, sometimes even while the pool is still under construction! Over time, our pools become thriving ecosystems. Within just a couple of years, you’ll find swallows dipping, dragonflies, newts and underwater pond life tucked away in the planted areas. Around the water's edge, you'll see pollinators, birds bathing and bats in the evenings. Giving a home to an abundance of wildlife, a natural swimming pool plays a vital part in protecting our planet and taking care of your health and wellness, naturally." - Hannah, Ellicar

Complementing this view, Gartenart underscores the personal wellness benefits of swimming in natural water.

"Swimming in natural water can have a calming and restorative effect on mental health, reducing stress and promoting relaxation. It's excellent for physical exercise, enhancing cardiovascular health, muscle strength, and overall fitness." - Gartenart

In addition to increasing biodiversity by providing habitat, natural swimming pools are also much better for the environment compared to traditional pools as they eliminate the need for harmful chemicals (and the risk of chemical runoff into surrounding areas) and mitigate the considerable energy consumption associated with conventional pool maintenance.

Design and Construction

Although they may, in some cases, look simply like a large garden pond, there is a significant amount of technical design behind creating consistently healthy, chemical-free, naturally balanced clean water; as Hannah from Ellicar explains,

"We size our biological filtration systems to work with the volume of water and the number of swimmers per day in our pools, making the pipework, pumps, flow rates and water plants totally bespoke for each of our designs. If a pool’s filtration system has been designed incorrectly, it can lead to an imbalance in the water, which means the oxygenating plants don’t grow properly, and the ecosystem fails. And whilst natural pools require less maintenance than conventional chlorinated pools, if a pool has not been built to allow for an easy maintenance regime, it can lead to phosphorous overburden and hygienic water issues.” - Hannah, Ellicar

Ellicar began fifteen years ago with a personal project—a natural swimming pool in the founders' garden, following their training as water specialists with Austrian natural pool pioneers, Biotop. This initial venture sparked the creation of their company, which has since evolved into a renowned family business. The team brings a deep-rooted passion for natural pools and gardens to every project, reflecting their commitment to both family values and ecological integrity, and their process for creating a natural swimming pool is professional and meticulous, as Hannah explains,

“After an on-site consultation with our designer, Sarah, we start by drawing up concept plans so our clients can really visualise the design of their pool and/or garden. Once they are happy with the concept, we move to construction drawings, creating 3D designs for every aspect of the pool – from the reinforced concrete internal walls to the complex deck hatches that allow us to access the filter chambers for servicing. After this, we’re ready to get on site and start bringing our client’s dream outside space to life! Depending on the size and complexity of the project, this can take as little as six weeks, but often it takes around 10-15 weeks for full construction and installation of the pool." - Hannah, Ellicar

As well as designing entirely new swimming ponds, many swimming pond specialists also offer pond and lake conversions, such as Gartenart’s swimming pond at Brandon Parkes, Hampshire, pictured below (left) and at the top of this article.

“The client wanted to convert an existing pond which was built by the previous owner and was looking murky and not appealing as the rest of the garden. We usually check the existing elements of the garden before starting the design and in this case, we decided to keep a similar footprint of the existing pond, increasing the length slightly to create a link between the higher level and the lower level of the garden. We wanted to take advantage of the big slope nearby, initially with a slide, which has since been transformed into a rocky waterfall.” -Gartenart

Temperature is often a consideration for those new to the concept of natural swimming pools in the UK, however as Gartenart notes,

“We almost always find that once they are swimming in the pond, temperature is not the issue they thought it was beforehand.” - Gartenart

Garden Integration

Integrating a natural swimming pool seamlessly into the garden design is essential for creating a harmonious and immersive outdoor experience. By thoughtfully blending water features with the landscape, both the aesthetic appeal and the functionality of the space are enhanced, allowing the entire garden to become a tranquil haven. This holistic approach ensures that the swimming area feels like a natural extension of its surroundings, maximising the enjoyment and connection with the environment for everyone who uses it.

“For Southwell, we were asked to create a natural swimming pool and naturalistic garden for our clients to relax and enjoy spending time at home with their family. We designed the garden around a small natural pool, with a swim zone 3m wide and 10m long. A beach at the shallow end is perfect for small children to access the pool and for stepping slowly into the water in the depths of winter. We incorporated our clients’ cabin at the far end of the pool. It opens onto a deck with the side patio creating a generous living space for sun loungers, BBQs and outdoor living adjacent to the water. The borders are full and brightly coloured, with plants reminiscent of our client’s childhood in Kenya mingled with grasses for a looser feel. Flowering perennials attract pollinators and are left standing through winter for seedheads for the wild birds.” - Hannah, Ellicar

Successfully integrating a natural swimming pool into a garden requires thoughtful consideration and imagination. Proper placement ensures the pool enhances the beauty of the landscape and effectively maintains water quality. Strategic positioning can prevent common issues such as leaf accumulation, insufficient sunlight, and contamination from runoff, all of which can significantly impact the pool’s ecological balance.

“Its important to locate a natural swimming pool to work with nature instead of against it! For instance, it is not advisable to place a pool too close to deciduous trees, as the leaf fall in autumn can cause huge issues if they clog the filter and burden the water with unwanted nutrients which causes an imbalance leading to algae. It’s also important to locate the pool somewhere it will get plenty of sun so it warms up nicely! Another key location factor is to never place a natural pool at the bottom of a sloped site, or anywhere it is at risk of being contaminated with surface water runoff, as this can hugely impact the water balance.” - Hannah, Ellicar

Besides integrating the swimming pool into its environment, it’s also important to consider the individuals who will be enjoying the space. By understanding their unique needs, preferences, and interests, a truly personalised environment can be created—one that resonates deeply and transforms the garden into a meaningful and celebrated part of life.

“To the side of the garden is a botanical medicinal border -our clients are both practitioners- this was great fun to research and plant. One of our favourite features is a tiny stream we designed to look like a Scottish burn, it sparkles down the hillside, through a scree garden of Scottish cobbles planted with aromatics and creeping thyme and disappears under the deck walkway into a hidden balance tank.” - Hannah, Ellicar

Sauna Symbiosis

Combining a natural swimming pool with an outdoor sauna is an increasingly popular choice, as the health benefits of both are complemented and enhanced by the other. Having a cool, natural body of water to dip into between sauna sessions—rather than heading indoors for a cold shower—allows for uninterrupted immersion in nature.

“Natural swimming pools and outdoor saunas are a match made in heaven! Outdoor living and wellness areas are becoming more and more popular with our clients. The use of cold plunge pools after a sauna has well-documented health benefits: releasing adrenaline and endorphins that can reduce stress levels, boost your metabolism, increase your blood flow, and boost your immune function. Anecdotally, a few of our clients swear by this ‘contrast therapy’ to improve their quality of sleep.” - Hannah, Ellicar

Considering the positioning of a natural swimming pool in relation to an outdoor sauna is crucial for optimising the overall wellness experience. A thoughtfully designed path connecting the pool and sauna creates a seamless transition between the two, promoting relaxation and maintaining a sense of connection to the natural surroundings.

“When designing a natural pool with a sauna, we think about the physical access that means our clients are able to safely plunge into the cold water and exit again easily and quickly—either a ladder for quick access to the ‘deep end’ or a shallow beach that slopes into the water so you can wade in and submerge yourself at will. But equally, we design the transition between the sauna and the pool to be a sensory experience in itself. Whether it is a mown path between wildflower meadow borders or a decked walkway with lighting and contemporary planting, we design the wellness space our clients will love and use for years to come.” — Hannah, Ellicar

It’s clear that beyond improving physical fitness, the combination of natural swimming ponds and outdoor saunas creates a holistic and rejuvenating outdoor wellness experience. This synergy is beautifully captured in the design of a recent project we collaborated on with water garden designer Calum Gordon (of aptly named ‘Splash Gordon’), pictured below. The serene view of the natural swimming pool from the sauna window plays a central role in the experience. As Calum notes,

“It’s the perfect combination! Swimming in general is very good for both mental and physical health, but actually just being by the water and looking at it is very calming—it’s nice to be able to look over the water from the sauna window. In winter especially, it’s so good to walk out of the sauna and into the pool.” — Calum, Splash Gordon

With careful consideration, both a natural swimming pool and an outdoor sauna can be expertly tailored to suit specific needs, creating an outdoor living space that reflects individual interests and lifestyle. Whether the goal is to establish a tranquil retreat, a space for cultivating fitness, or a vibrant social hub, each element can be customised to accommodate experience priorities, mobility requirements, and aesthetic preferences. Together, the swimming pond and outdoor sauna form a cohesive wellness environment that cultivates presence in the body and a connection to nature.