Biological Water Quality (Trophics) 2003
All major Berlin streams are dammed and extremely slow-flowing, with the lake-like expansions of the Spree and Havel in which showing very great detention times.
Unlike natural streams, dammed stream segments, like country lakes, are sensitive to nutrient immission. Due to the high nutrient presence in the Spree-Havel area, the water quality of the Berlin stream segments is characterized by the results of Eutrophication, and to a lesser extent by external immission of easily degradable organic substances. Therefore, a water-quality classification according to the saprobic system is not practicable for Berlin.