Windermere Bathing Water Site Closed Due to Potentially Toxic Algae
One of Windermere’s four designated bathing water sites has been marked as “bathing not advised” by the Environment Agency due to a potentially toxic bloom of blue-green algae (BGA). Yesterday, the Environment Agency issued advice for the Lakeside YMCA bathing site due to “pollution from harmful algae”.
Save Windermere has long argued that the four bathing water classifications on Windermere are often used to give a misleading impression of overall water quality. Today’s warning underscores that not enough has been done to protect the lake and its recreational users.
While not all BGA blooms are toxic, Environment Agency internal guidance acknowledges that BGA cells are considered “harmful 50% of the time.” Contact with BGA can cause symptoms such as rashes, nausea, vomiting, blistering, abdominal pain, and in chronic cases, respiratory and allergic conditions including bronchitis and dermatitis.
Crucially, bathing water status does not account for the presence of BGA. The current classification system, based only on E. coli and intestinal enterococci levels, fails to fully reflect the health risks posed to swimmers.
Climate change is expected to make BGA blooms more frequent and more dangerous, with heavier rainfall increasing sewage discharge—adding fertilising nutrients to the lake—and more droughts reducing river flow and flushing capacity.
By United Utilities’ own admission, 16 discharge points release into the Windermere catchment. This includes up to 13 million litres of treated effluent per day and over 18,000 hours of untreated sewage spills since 2020. These discharges are rich in phosphorus, the main driver of algal growth.
In its natural state, Windermere would be classified as oligotrophic, meaning it should naturally be so low in nutrient that algal blooms would be incredibly unlikely or infrequent, or would not occur at all. This is why Save Windermere is calling for a complete end to sewage pollution in the lake.
