Luxembourg Authorities Lift Ban on Swimming at Upper Sûre Lake

On Tuesday 24 June 2025, the Water Management Agency (AGE) of Luxembourg's Ministry of the Environment, Climate and Biodiversity reported that swimming is once again permitted on the beaches of the Upper Sûre Lake.

Following the proliferation of cyanobacteria (blue-green algae) detected in these areas last week - accompanied by the presence of high concentrations of toxins produced by the cyanobacteria - the situation has returned to normal. Consequently, swimming and recreational and sporting activities are once again permitted in these areas.

The Water Management Agency noted that the drop in temperatures has led to a sharp decline in cyanobacteria biomass. Moreover, monitoring carried out by the Luxembourg Institute of Science and Technology (LIST) has confirmed the dissipation of the blooms, as well as the drop in toxin concentrations below the alert threshold. As such, the authorities have lifted the alert regarding toxic risks to public health linked to the presence of cyanobacteria blooms.

The current situation regarding the opening or closure of official bathing sites can be monitored on the AGE website: https://eau.gouvernement.lu/fr/domaines-activite/eauxbaignade/sites-de-baignade.html