Big Windermere Survey - May 2024 Results

The Freshwater Biological Association and Lancaster University are delighted to share with you the results of the May 2024 Big Windermere Survey!

On the morning of Sunday 12th May 2024, between 10am - 12pm, water samples were collected by volunteers from 107 locations around Windermere, Esthwaite Water, Grasmere, Rydal Water and the streams and smaller tarns in the Leven catchment. This was the eight survey to date and represented the spring season and final survey of the survey’s second year. You can see all locations on this map.

Samples have been analysed for the concentration of nutrients within research laboratories at Lancaster University and bacterial analysis was completed at externally-accredited laboratories following standard protocols. To find out more about the water quality parameters that are analysed, please read our Water Quality Guide.

Data from the May 2024 Survey reveal that 66% of samples collected from Windermere shoreline locations had elevated concentrations of phosphorus, sufficient to drop these sites below the standards required for Good status under the Water Framework Directive. For river locations, 79% of water samples collected were consistent with High phosphorus status, although this is 14% less than river locations sampled in the spring 2023 survey.

For bacteria, 88% of samples collected from Windermere shoreline locations had low concentrations, consistent with standards from the European Union Bathing Water Directive for Excellent bathing water quality. This is 12% less than Windermere shoreline locations in the spring 2023 survey. For river locations 21% contained elevated concentrations of E.coli or intestinal enterococci bacteria, moving these sites below the standards required for Good bathing water quality.

Read our Results Summary which explains the results in more detail and the full data set is now available to view on a map via Cartographer.

Many thanks to our dedicated team of citizen scientists who contributed towards the May survey and who are helping us to gain an understanding of the water quality in the Leven catchment throughout the seasons.

For any queries, please contact: windermere@fba.org.uk or have a look at out our FAQs.