Bruchertalsperre: More swimming areas closed due to blue-green algae Wupperverband and the Health Department of the Oberbergischer Kreis provide information.

Oberbergischer Kreis. Currently, there is a swimming ban at the swimming areas DLRG-Haus, Segelclub, and Staumauer of the Bruchertalsperre due to blue-green algae. This means that three of the four swimming areas are currently closed. There is no swimming ban for the Campingplatz swimming area.

The health department of the Oberbergischer Kreis and the Wupperverband are monitoring the development at the swimming areas. The Segelclub swimming area was already closed last Friday (Press release from 07.08.2026). The DLRG-Haus and Staumauer swimming areas followed today.

The health department also appeals to individual responsibility when engaging in activities on the reservoir. Contact with blue-green algae must be strictly avoided!

What are blue-green algae:
Blue-green algae are not actually algae but bacteria, which often have a blue-green coloration. Blue-green algae naturally occur in water bodies. However, when they multiply excessively, they cause problems. High temperatures promote their development.

Avoid contact:
Most types of blue-green algae are harmless to humans and only cause an unpleasant odor when they decay. However, some can produce toxins that may affect health. At high concentrations, blue-green algae can cause symptoms such as allergic reactions, skin irritations, or earaches in humans and animals (e.g., swimming dogs). Ingestion may lead to nausea, diarrhea, and vomiting. Particularly young children and very sensitive individuals should avoid contact with blue-green algae.

Identifying blue-green algae:
When blue-green algae proliferate massively, they accumulate on the water surface (streaks). The cyanobacteria turn the water blue-green (cyan). An initial sign of blue-green algae formation is reduced visibility due to strong water turbidity. Refrain from swimming if you stand knee-deep in the water and cannot see your feet. Avoid swimming if you notice distinct green or blue-green streaks on the water surface.

More information about this topic can be found at www.obk.de/badegewaesser and www.obk.de/blaualgen.