Big Windermere Survey - November 2024 Results

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

On the morning of Sunday 17th November 2024, between 10am - 12pm, water samples were collected by volunteers from 106 locations around Windermere, Esthwaite Water, Grasmere, Rydal Water and the streams and smaller tarns in the Leven catchment. This was the tenth survey to date and represented the autumn season and the second survey of the third year of the Big Windermere Survey. 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 November 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, while the other 34% of Windermere shoreline locations meet standards for either High or Good status. For river locations, 100% of water samples collected had low concentrations of phosphorus that were consistent with High or Good status.

For bacteria, 97% of samples collected from Windermere shoreline locations had low concentrations, consistent with standards from the European Union Bathing Water Directive for Excellent or Good bathing water quality and 3% of samples collected contained elevated concentrations of bacteria. For river locations, 13% contained elevated concentrations of E.coli or intestinal enterococci bacteria, moving these sites below the standards required for Good bathing water quality. The remaining 87% of river locations met standards for Excellent or Good bathing water quality.

Read our results summary below which explains the results in more detail and the full data set is now available to view on our interactive map.