Summer is here – one wants (and needs) a refreshing swim. I don’t know if you have ever heard of this classification: there are the sea people, and then the swimming-pool people. The firsts bath in a natural surrounding, while the second ones get a dose of chlorine if they want to swim. Right? In fact, you could also ‘go natural’ in a swimming pool. Particularly, in a sort of ecological bathing space also called a natural pool. The concept refers to constructed pools or ponds designed for swimming, but with room for nature: they use plant life – and stone walls and physical filters – to maintain the water clean. A natural pool is intended to encourage natural biological activity, and this is why it functions without added chemicals, like chlorine, UV radiation or ultrasonic devices – which would have the opposite effect on the ecological environment. The process by which plants are used to clean up contaminated environments is called phytoremediation and it is applied also against many types of polluters from the soil – including metals, pesticides, explosives, and oil – for example to restore the ecological balance in a mining area.

A natural pool, by not using chemicals, typically requires a whole section – ‘regeneration zone’ – that is just for water to be cleansed biologically. The remaining swimming area is therefore limited, which makes smaller-sized natural pools more complicated to put in place. Also, ecological pools cost more to install. Over time, however, they are less expensive because of the absence of chemicals products to purchase and because, if properly designed, they don’t need specific maintenance. One would think then that the larger size factor and the reduced operating costs in the long term would make natural pools particularly suited for bigger public infrastructures. However, while natural swimming pools have been around for a good sixty years, they were originally used in private residences. Legal and technical barriers had to be overcome to enable the step from private to public natural pools in the 1990’s, mainly in Europe. Today, the trend seems to be expanding.

In Belgium, Antwerp’s Boekenbergpark offers since 2007 the country’s first ecological public swimming pool. Built by the German landscape architect firm Dongus, its floor is lined with more than 22,000 aquatic plants to maintain the water purity. Therefore, it does not content any added chemicals. Open to the public from May to September, this open-air swimming facility consists of a large 73m long pond, a small play pool and a large sunbathing area. Combined with its situation in the middle of the park, it has become a very popular spot for a summer swim in the city – apparently it can get quite crowded on hot days!  

Other public authorities have followed the example. Webber Park natural pool in Minneapolis was the first natural swimming pool in the United States in 2015. And at the same time, the UK had also its first public natural swimming pool at King’s Cross in London as a temporary art installation. The Naturbad Riehen, in Switzerland, allows, for a small fee, to replicate the experience of bathing in a lake surrounded by contemporary design. 

In conclusion, these pools seem to be a good natural way to cool off, especially in an urban environment. You may be sharing your bath with frogs, but, hey, the absence of added chemicals is super good for your skin.