Big Windermere Survey - February 2023 Results

We are delighted to share the results of our third Big Windermere Survey, which provides an intensive snapshot of water quality within the Leven catchment on one day. Water samples were collected by volunteers from 93 sites throughout the Leven catchment, including from Grasmere, Rydal Water, Blelham Tarn, Esthwaite Water, Ghyll Head reservoir, Windermere and a number of key inflow streams for Windermere. All samples were taken between approximately 10 am and 2 pm on Sunday 5th of February.

Samples have been analysed for a range of water quality parameters within research laboratories at Lancaster University and bacterial analysis was completed at externally-accredited laboratories following standard protocols. The data are all open access and available to view on a map via Cartographer. We have also created a briefing note, which you can download below, to explain the results in more detail, and what they tell us about the water quality and bacteriology of Windermere on this sampling occasion.

We have presented the water quality results in the context of EU Water Framework classifications and the bacteria data in the context of the EU Bathing Waters Directive classifications. However, classification of water quality against standards requires long term datasets, comprised of multiple samples taken from each location to capture variation in water quality, such as between seasons. Water quality standards are used to provide context for the results. As future surveys generate additional data, we will be able to undertake more accurate classification of water bodies in the Leven catchment against water quality standards.

We are still awaiting the results of the extra eDNA tests that were run alongside the usual sampling in February, we will publish those as soon as they are with us!

With four surveys completed, the last one taking place on 23rd April of 2023, we are looking forward to seeing the full year’s dataset and our understanding grow.

Click to read our Summary Report, see the full dataset on Cartographer.

For any queries, please contact: windermere@fba.org.uk Please have a look at out our FAQs and our Water Quality Guide.