Blue-Green Infrastructure Creates Public Space: Flussbad Berlin
Swimming in the Spreekanal
When we hear the term, “public space”, we usually think of a neighborhood park, a plaza downtown, or even a sidewalk down main street. It’s usually not the canal that runs through a dense urban area, completely surrounded by concrete, brick, and steel. The, “Flussbad Berlin e.V.”, wants to change that notion by turning the Spreekanal, a small offshoot of the Spree river that actually forms Berlin’s famous, “Museum Island”, into a 835 meter (2740 ft.) natural swimming pool or, “public blue space”.
It’s not necessarily a revolutionary concept. Zurich’s, “Badis”, have been around for over 100 years, and Copenhagen (of course Copenhagen) opened up the, “Harbor Bath”, in 2008. It’s actually becoming a bit of a new urban trend, catching on in basically any city with an unused, post-industrial, body of water including, Chicago, London, or New Delhi. With many major cities struggling to find enough space for development, let alone public spaces, it’s no wonder that every piece of open or unused space is being explored as potential public space. And why not? Over half of the world’s population now live in cities (55%) and that figure is expected to continue to grow, reaching 68% by 2050. We need to ensure our urban spaces are used as efficiently as possible, and to the greatest benefit of all urban dwellers.
Berlin’s Flussbad is an incredibly fascinating project that goes beyond what some of it’s contemporaries have accomplished. Instead of just plopping a fancy walled pool into the Spree river, the proposed project will utilize green infrastructure to keep the river water clean and expand the amount of usable public space. After all, Berlin already has the, “Badeschiff”, a tiny rectangular chlorine pool and bar that sits in the Spree, and is usually packed full with people. It’s cool, but it is definitely more of a one-off kind of experience.
Back to the Flussbad…
Blue-Green Infrastructure and Public Spaces
The Flussbad will be comprised of three main sections. Starting at the Fischer Insel on the canals east entry point, the project will partially restore the natural river. To do this, parts of the concrete wall that line the river bank will be removed and replaced by riparian vegetation. This natural buffer between urban development and river will help mitigate the polluting impacts of stormwater-runoff, while also enhancing available public green-space, and bio-diversity in downtown Berlin.
If you’re wondering why we channelize rivers in the first place, it’s mainly to prevent flooding. The river is drudged and then basically encased in concrete to collect and quickly move water out of the area. Our impermeable urban surfaces are incapable of absorbing water from rainfall, which means this water has to be collected and moved out somehow. Storm drains move the accumulating stormwater to larger bodies of water, such as, rivers or reservoirs, which fill or move the water out of the inhabited areas. As you can probably imagine, these engineered systems are expensive to build and maintain, and often times, their capacity is exceeded. They can also cause severe damage downstream by polluting natural rivers, flooding other areas, or increasing erosion.
A solution to this flooding problem is to create more permeable urban surfaces, such as, green roofs, raingardens, bioswales, parks, and so on, so that greater amounts of stormwater are absorbed and processed on site. Sadly, increased vegetation won’t be able to achieve this on it’s own and will have to be combined with an expansion of underground water storage tanks like this one being built in Berlin’s Mauerpark. However, unlike gray infrastructure, green infrastructure provides us with a plethora of ecosystem services such as clean air and water, cooler urban spaces, greater biodiversity, and improved human health and well-being, to name a few.
The second section of the Flussbad will consist of a 400 meter (1312 ft.) long natural filtration system that could potentially mirror the components of the, “Hans-Wilhelm”, an old barge that was repurposed into a specially designed test filter and is currently located at the, “Flussbad Garden”. The test filter utilizes a combination of gravel, pumice, aquatic vegetation (Hornwort, Yellow Water Lily, Eurasian Watermilfoil) and Mussels to eliminate pollutants and bacteria that especially tend to surge into the Spreekanal during rainstorms. According to the 2017/18 test results, the test filter met expectations and kept the water clean enough to swim in, but due to the lack of rainfall during the unusually hot and dry summer, it was only truly put to the test once. It was so hot in Berlin last year, I probably would’ve just jumped into the Spree anyways.
Speaking of jumping into the river. If you love swimming and are looking for something unique to do this summer, check out the annual, “Flussbad Cup”.
These two blue-green engineered sections will enable the third and final section. The pièce de résistance. The 835 meter (2740 ft.) natural public pool that flows by some of Berlin’s most captivating historical buildings, including the, “Bode Museum”. Imagine getting to swim by something like that. It would be a whole new way to experience and enjoy Berlin’s historic Mitte, which also appears to be the project’s main goal. The dedicated urbanists at Flussbad e.V. want to reactivate a cultural area of Berlin that has become somewhat stale and overrun by tourists. To turn a forgotten side of the Spree into an inviting space that encourages you to recreate, hang out for a bit and enjoy the cool water on a hot summer day. Because right now, it’s kind of a gray urban space you want to quickly pass through so you can go Salsa and Tango at Monbijou Park.
The project “Flussbad Berlin” seeks to reactivate the Spree Canal in its total length as a public space designed for recreation and to foster an active experience of nature within the city.
The Flussbad is a unique sustainability project that does not seek to create a public space by whatever means necessary, but instead it will do so by restoring the natural ecological system. By using aquatic vegetation and riparian buffers instead of chlorine, the Flussbad will improve the city’s ecological health, and therefore, human health and well being. By ensuring that the Flussbad has multiple public access points instead of a single paid entry point, it also ensures that the space is equitable as it is accessible to everyone. And, by revitalizing the area and making it more attractive to residents, tourists and investors, the city also gains a valuable economic asset.
For more information on the Flussbad Berlin, check-out their website at www.flussbad-berlin.de. If you want to know more about Green or Blue Infrastructure take a look at this extensive report by TO2-federatie.
Thanks for reading!
-Andrew
Originally published at https://thesustainablecity.blog on May 28, 2019.
