Everything You Never Knew You Wanted to Know About Berlin
Pororoca is a phenomenon observed on the Amazon River in which a wave of up to 5 m rolls up the river from the Atlantic, devastating the river banks and carrying swarms of ecstatic surfers who can enjoy rides as long as 37 minutes. It is not something you would expect to find in Berlin; after all, the Spree is hardly a ‘surfable’ waterway even on windy days.
However, now and then, the Spree also flows ‘backwards’, and the water can be observed moving upstream, back toward the Müggelsee. The lake in Köpenick, which is part of the Spree’s watercourse, is also a reservoir providing Berlin with 25% of its water. On hot summer days, when Berliners shower more, drink more and need more water for their plants, the lake loses even more volume than normal; in addition, water from the lake is also evaporating due to the heat. Whatever the Spree carries with it, is not enough—especially since its water is also used to fill the former open-pit mines in the Lausitz Region south of the city.
When the Berlin sewage treatment centre releases its purified water back into the river – and those might be up to 500 million litres per day! – the water level in the Müggelsee suddenly becomes lower than that of the Spree. As a result, instead of pushing towards the Havel, the river begins to move backwards towards the lower surface, as water naturally would.
The Wasserberg (Water Mountain) created in Berlin when we shower and splash makes the Spree stop in its track and flow back down into the lake. And with current temperatures outside going in excess of 35°C, this wave might just be a-coming.
The text was originally published in “Notmsparker’s Berlin Companion” (Part I).