Outdoors

Switzerland's new natural swimming pool does away with the chemicals

The Naturbad Riehen swimming pool is entirely chemical-free (Photo: Helen Schneider)
The Naturbad Riehen swimming pool is entirely chemical-free (Photo: Helen Schneider)
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Features include a wading pool for toddlers, a separate pool with a sloping gravel beach, a water-slide, a 25-meter lap pool and a diving board (Photo: Helen Schneider)
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Features include a wading pool for toddlers, a separate pool with a sloping gravel beach, a water-slide, a 25-meter lap pool and a diving board (Photo: Helen Schneider)
Aquatic plants kill off germs while absorbing nutrients from the water for growth (Photo: Helen Schneider)
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Aquatic plants kill off germs while absorbing nutrients from the water for growth (Photo: Helen Schneider)
Features include a wading pool for toddlers, a separate pool with a sloping gravel beach, a water-slide, a 25-meter lap pool and a diving board (Photo: Helen Schneider)
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Features include a wading pool for toddlers, a separate pool with a sloping gravel beach, a water-slide, a 25-meter lap pool and a diving board (Photo: Helen Schneider)
Lupp says a point of difference for the Naturbad Riehen is that it's au naturel from the ground up, allowing for better integration of the pool's natural technology with its wooden infrastructure (Photo: Helen Schneider)
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Lupp says a point of difference for the Naturbad Riehen is that it's au naturel from the ground up, allowing for better integration of the pool's natural technology with its wooden infrastructure (Photo: Helen Schneider)
Features include a wading pool for toddlers, a separate pool with a sloping gravel beach, a water-slide, a 25-meter lap pool and a diving board (Photo: Helen Schneider)
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Features include a wading pool for toddlers, a separate pool with a sloping gravel beach, a water-slide, a 25-meter lap pool and a diving board (Photo: Helen Schneider)
An on-site cafe offers refreshments and snacks, with wooden decking and grass providing a place for some time out (Photo: Helen Schneider)
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An on-site cafe offers refreshments and snacks, with wooden decking and grass providing a place for some time out (Photo: Helen Schneider)
Lupp says a point of difference for the Naturbad Riehen is that it's au naturel from the ground up, allowing for better integration of the pool's natural technology with its wooden infrastructure (Photo: Helen Schneider)
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Lupp says a point of difference for the Naturbad Riehen is that it's au naturel from the ground up, allowing for better integration of the pool's natural technology with its wooden infrastructure (Photo: Helen Schneider)
Features include a wading pool for toddlers, a separate pool with a sloping gravel beach, a water-slide, a 25-meter lap pool and a diving board (Photo: Helen Schneider)
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Features include a wading pool for toddlers, a separate pool with a sloping gravel beach, a water-slide, a 25-meter lap pool and a diving board (Photo: Helen Schneider)
The Naturbad Riehen swimming pool is entirely chemical-free (Photo: Helen Schneider)
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The Naturbad Riehen swimming pool is entirely chemical-free (Photo: Helen Schneider)
Lupp says a point of difference for the Naturbad Riehen is that it's au naturel from the ground up, allowing for better integration of the pool's natural technology with its wooden infrastructure (Photo: Helen Schneider)
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Lupp says a point of difference for the Naturbad Riehen is that it's au naturel from the ground up, allowing for better integration of the pool's natural technology with its wooden infrastructure (Photo: Helen Schneider)

A whiff of chlorine is virtually synonymous with taking a dip in a swimming pool. While it helps to kill off bacteria, it also serves as a subtle reminder that you are wading around in chemically treated water (if tasting the odd mouthful just isn't enough). Switzerland's Naturbad Riehen swimming pool is entirely chemical-free, relying instead on a biological filter system to provide clean and natural water for thousands of patrons, no itchy red eyes in sight.

A town of around 20,000 people, Riehen sits just outside of Basel on the Swiss-German border. This section of the border wraps around Riehen in such a way that in 2006, the town's old swimming pool had to be demolished to make way for a tunnel connecting two German cities on either side. With the controversial roadway completed in 2013, the people of Riehen were quick to reclaim their territory.

"The citizens wanted their pool back and believed that a natural swimming pool would suit their interest in bathing, swimming and playing, just as well as a traditional pool," Christian Lupp, Recreation and Sports representative from the Municipality of Riehen tells Gizmag. "Furthermore, there was the understanding that the natural water is better for the skin and eyes and feels smoother and softer".

Features include a wading pool for toddlers, a separate pool with a sloping gravel beach, a water-slide, a 25-meter lap pool and a diving board (Photo: Helen Schneider)
Features include a wading pool for toddlers, a separate pool with a sloping gravel beach, a water-slide, a 25-meter lap pool and a diving board (Photo: Helen Schneider)

The first man-made natural swimming pools date back to the early 1980s in Austria, though these were largely for private use. The precise mechanics vary between each natural pool, but they typically contain the swimming water inside a membrane and then a separate water regeneration zone to clean it. Aquatic plants kill off germs while absorbing nutrients from the water for growth. Often the water is pumped across the surface of rocks or gravel to which the bacteria clings, functioning as a natural filter.

Since the 1980s, the concept has been commercialized and spread to different parts the world. Natural pools for public use have popped up in Germany, the UK and one is currently under construction at Webber Park in Minneapolis, set to be the first in the United States. Lupp says a point of difference for the Naturbad Riehen is that it's au naturel from the ground up, allowing for better integration of the pool's natural technology with its wooden infrastructure.

"Many other projects are conversions of traditional pools," he explains. "Our pool is absolutely built from zero, allowing the extraordinary possibility of a holistic design and a combination between the natural technology and its according architecture."

An on-site cafe offers refreshments and snacks, with wooden decking and grass providing a place for some time out (Photo: Helen Schneider)
An on-site cafe offers refreshments and snacks, with wooden decking and grass providing a place for some time out (Photo: Helen Schneider)

Swiss architects Herzog & de Meuron designed Riehen's new swimming pool to accommodate the town's families and blend in with the greenery that surrounds. Features include a wading pool for toddlers, a separate pool with a sloping gravel beach, a water-slide, a 25-meter (82 ft) lap pool and a diving board. An on-site cafe offers refreshments and snacks, with wooden decking and grass providing a place for some time out.

Officially opening for business in mid-June, the Naturbad Riehen is equipped to deal with 2,000 daily visitors. We're guessing the residents of Riehen are pretty happy with their new pool, with the possible exception of those in the business of selling swimming goggles.

Source: Naturbad Riehen

8 comments
Brian M
Not sure if I would fancy that! The removal of untreated faecal and other unsavoury matter will remain in the water till it reaches the biological filters, so the risk of bacterial and other bugs is going to be higher especially if a lot of people are using the pool at the same time!
scott melnick
I'd love to know the cost differential both in initial construction and ongoing maintenance between this pool (which looks incredibly beautiful!) and a traditional chlorine-laced pool.
Rann Xeroxx
Hmm, there are a lot of human pathogens that I am not sure I would want to trust that this pool is killing/filtering out. Ebola anyone?
Expanded Viewpoint
How about pumping the water through a two stage filtering system, the first one where large particulates are removed and the media is washable, then on to a second stage where a sintered block of tiny silver and or copper particles kills off the bacteria? And for additional treatment and peace of mind, have a UV chamber after that. Randy
mvp
I'll keep on enjoying my salt water filtration any day!
Pete83
@mvp yes but a salt water pool is just another way of chlorination
RodneyW123
I like this idea of a natural swimming pool with no harsh chemicals. There is nothing to harm your skin or turn your hair different colors. I'd love to take a swim in hat pool and see how it compares to the pools we normally see. http://www.pooltime.com.au/pool-chemicals
Nik
France has millions of man made ponds, constructed after WW2 so that it millions of farmers could breed fish for food. They range in size from 25 meters square/diameter, up to several hectares. Most are now obsolete as 'fish factories' and are used for recreational purposes, including fishing and swimming. The majority are constantly fed by springs, streams or rivers, that provide a change of water to prevent stagnation, and are perfectly safe for swimming, as if fish are 'happy,' so are people. For an artificial pool, the main factor for keeping it clean, is the change of water rate, combined with a filtration system that can cope with that change rate. It is the artificial stagnant pool/pond that requires chemical cleansing, and can breed all manner of nasty's, even with the evil chemicals.