Blue green algae bloom on the River Thames


water sample

We are pleased to report that recent lab analysis of water samples show that levels of blue-green algae are decreasing. Cooler weather and increased river flow following rainfall will help improve conditions. 

Because the bloom continues to persist along this stretch of the River Thames, including at the Ham and Kingston Designated Bathing Water, we continue to treat this as a priority incident. This is due to the risks to human health, animals, and the wider environment. 


We will provide further updates if there is any significant change or when the designated bathing water has reopened, which will be after 2 weeks of clear results. 


We continue to urge people:  

  • do not enter the water  
  • avoid contact with the water   
  • keep animals away from the water - and do not allow them to drink it.  

For further information and advice visit Algal blooms: advice for the public and landowners - GOV.UK.

To find out the latest updates on the Ham and Kingston designated bathing water site visit swimfo