Blue algae, the smelly blue -green stuff, arises because bacteria grow fully at high temperatures. Swimming in water where blue -green algae occurs is not recommended. It can cause substantial health problems.
People who still take a dip can get skin and gastrointestinal complaints. Children and dogs in particular can get very sick.
Where can you swim safely?
View the map below where you can safely take a refreshing dip.
This ticket was updated on July 11, 2025. Look for the current image swimming water.nl.