While living in Copenhagen, I adored taking a quick morning dip on my way to work, directly in the inner harbor in the middle of the city. This huge outdoor pool is a place for taking walks, having picnics or drinks with friends, strolling around flea markets, enjoying open air concerts or just getting some fresh air and spending time outdoors. And all those activities feel even better when you know the water is clean enough to jump in at any time. Whereas in Copenhagen the municipality made this luxury possible fifteen years ago by expanding and modernizing its wastewater infrastructure, inner city river bathing has been the standard in Zurich and Basel for decades. There, people enjoy moving through town by floating with the current, transporting their belongings with waterproof bags.
Copenhagen's Harbor Bath at Islands Brygge
Swimming in Zurich's Limmat river
Historically, most towns and cities have been constructed along a river. These arteries of urban life provided the water needed for drinking, washing, cleaning, transportation, disposing of waste and generating energy. The waterways were strategically important for trade, defense and power. Nowadays many urban rivers primarily carry tourist boats and are barely used by the local citizens anymore. But change is happening, thanks to persistent initiatives that strive to make the rivers accessible to the public again. This summer, after years of water cleanup, Paris opened three free swimming pools in a canal in the city’s northern districts. And Berlin has its own special version in the making: Flussbad Berlin. We met with Jan Edler, one of the project’s founders, for an interview at the Flussbad Garden, located just between the reconstruction site of Berlin’s City Palace and the German Foreign Ministry - at the original site of the River Spree’s last public swimming area, closed in 1925.
Swimming at Berlin’s Museum Island may look like this in the near future
Flussbad Berlin translates roughly to “River Pool Berlin,” but this initiative is about much more than swimming. In fact, the chance to swim along the UNESCO World Heritage Museum Island, smack in the middle of the German capital, is just a bonus. The award-winning project’s aim is to improve the water quality in a canal of Berlin’s River Spree, but also to challenge the understanding of sustainable urban development and the common view of urban waterways. A city river can be much more than an extended sewer! It is a natural resource: a lifeline of urban ecology.
The initial idea of Flussbad Berlin was born back in 1997, and the project maintains some spirit of the 90’s-era, when the city was still undefined and full of possibilities. Unused, undeveloped urban space made Berlin unique among capital cities. In those days, the project’s founders, Jan und Tim Edler, were running the artist collective and namesake club Kunst und Technik (art and technology) located directly at the River Spree, along the Museum Island. Mitte – then a run down district with a thriving underground scene – would eventually trade in its squatted buildings and empty lots for top real estate and endless new building projects. But, there was never a concept for the abandoned section of the Spree Canal, left over from earlier days of river transport and logistics. It was precisely this unutilized space flowing nearby their studio windows that inspired the two architect brothers to action. With most of their projects, the Edlers explore the potential for architectural spaces to become more dynamic. With Flussbad Berlin, they are working at the city planning scale for the first time, but their approach is similar: a neglected urban waterway is being transformed into a place of social and natural dynamism.
Flussbad Cup 2016 at the construction site of the Berlin City Palace
A three-part, mixed-use attraction is underway that will remind Berliners and tourists alike to use the city center for more than museums and consumption. An 825-meter swimming area at the Museum Island will be preceded by a 400-meter long natural plant and sand filter. Just upstream of the filter, a stretch of canal will be transformed into an ecological stepping stone – a habitat for flora and fauna, supporting biodiversity in the city.
Today, the River Spree, like many urban waterways, is polluted, and the main issue is the outmoded, mixed sewage system from the 19th century. Sewage pipes are used for wastewater, but also for storm water. With heavy rainfalls, these pipes overflow, and the overspill ends up in the Spree along with fecal matter and all its harmful bacteria, poisoning the water and depleting it of oxygen. Fish often die, and human contact with the water is worse than unappealing; it’s a major health hazard. Presently, this occurs on average 15 to 25 times per year. Going forward, as weather patterns become less predictable and more drastic, Berlin’s mixed-pipe system will become more overburdened. More overflows mean more contamination of the river and its adjacent lakes - and this in a highly developed, “first world” city. Even this summer, the annual Flussbad Cup swimming event had to be cancelled due to dangerous water conditions after heavy rains, highlighting the issue. Approaches are needed that align safe, even swimmable public water with increased quality of life. As Tim Edler puts it: “Clean water is a cultural asset.”
Visualization of the plant filter
The plant filter designed for the Flussbad project will treat the canal by biological means and provide clean water for the swimming area. Methods like this work by phytoremediation – from the Greek phyton (plant) and remediare (to remedy) – using certain plants together with microorganisms living in the sand around their roots to transform contaminants into harmless forms. However, this treated canal water eventually empties back into the rest of the polluted Spree. So, while the project has a relatively low ecological impact, Jan Edler explains that it should be understood as a pilot, which can be scaled up, and seen as a catalyst for further work to promote the value and benefits of sustainable development and clean water in the metropolis.
As the third element of the project, the lovely stretch of canal curving around Fischerinsel (Fisher Island), leading up to the plant filter will become a refuge for plant and animal life – an ecological stepping stone. By building natural surfaces into the channeled waterway, species can rest, reproduce and create an ecosystem here that will enhance the quality of the water and the entire atmosphere of the area. Similar to Manhattan’s High Line Park - a 2.33 kilometer stretch of elevated train tracks repurposed as an aerial greenway and urban park - Berlin will provide a kind of Low Line experience for those walking or biking along the new canal landscape.
Berlin's future "Low Line" park at Fischerinsel
All in all, a daring vision of swimming in Berlin’s city river has lead to a larger program for engaging with the urban ecosystem to improve the quality of life. Flussbad Berlin inspires Berliners and visitors to participate, to re-think sustainable urban development and to enjoy non-commercial activities in the city center. Who owns the city, anyway? The project reminds us to reclaim the city and shows us that there is strength in numbers. Founded in 2012, the Flussbad Berlin association with its 300-plus members has driven the realization of an idealistic project, 20 years in the making, and helped to anchor it within the Berlin Senate’s official directives. Their policy to make swimming in the Spree possible and to support projects working toward this aim is proof that visionary ideas can become reality. With a great deal of perseverance, Flussbad Berlin has paved the way for others who want to be part of this new paradigm of sustainable urban development.