Berlin issues blue-green algae warning for 2 Havel River swimming spots

Berlin health officials have issued a warning against swimming at two popular sites along the Havel River due to a large bloom of blue-green algae. The Breitehorn swimming spot in Spandau and the Radfahrerwiese area in Steglitz-Zehlendorf are experiencing a rapid growth of cyanobacteria, or blue-green algae. This has resulted in water visibility dropping below 0.5 meters, making emergency water rescue operations more challenging.

The State Office for Health and Social Affairs (Lageso) is conducting further testing for algae toxins at both locations, following recommendations from the Federal Environment Agency (UBA). Cyanobacteria proliferate when water temperatures increase and sunlight exposure is high, and sudden changes in water quality due to heavy rainfall and warm weather can also create favorable conditions for their rapid multiplication.

Fortunately, the remaining 37 official bathing spots across Berlin remain safe for use. Lageso continuously monitors all 39 designated swimming areas in the city throughout the summer season, regularly testing for bacteria such as Escherichia coli and intestinal enterococci to ensure water safety.