25 March 2025

A landmark science led report examining the water quality of Windermere – England’s largest natural lake – has been published. 

‘A Changing Windermere’, published by the Love Windermere Partnership, draws on decades of scientific data and analysis. 

Using research compiled by the Freshwater Biological Association combined with the most current data on Windermere water quality, the work has been produced under guidance from Lancaster University and has been reviewed by the UK Centre for Ecology & Hydrology and Environment Agency Chief Scientists Group. It brings together the latest research, highlights the ecological status of Windermere and explores the challenges around tackling pollution and the impacts of climate change. 

Key findings show: 

Phosphorus 

• Total phosphorus concentrations peaked in the 1990s but then fell and have remained relatively stable for the last 15 years largely due to improvements in wastewater treatment.   

Nitrogen 

• Total nitrogen concentrations have remained relatively stable in the north and south basins since 2008. 

Bathing waters 

• Windermere’s 4 designated bathing waters which monitor bacteria such as E.coli have consistently received the highest classification of cleanliness, ‘excellent,’ since 2015. 

Fish/species 

• The presence of many species of fish, including those indicating clean water and high-quality habitat, such as the Atlantic salmon and sea trout.  The presence of otters further indicates a high-quality environment. 

Climate change  

• Climate change affects the natural processes occurring within Windermere and its animals and plants, including algal blooms such as blue-green algae. The temperature increase in Windermere is notable – rising by 1.7C in the last 70 years – supporting earlier and longer algal blooms and favouring coarse fish like ruffle and roach but making conditions hard for the iconic Arctic charr. 

While progress has been made, the report is clear that further action is needed to reduce pollution, restore habitats, and race against climate change. 

Collaboration and Community Involvement 

The Love Windermere Partnership, a collaboration of local public, private and third sector organisations.  We are grateful for the support of local businesses and the decades of research and data collection from the science community.  Their work informs our work to protect and improve Windermere. The Partnership is committed to evidence-based solutions that balance the needs of nature, local communities, and the economy. 

Nigel Wilkinson, Chair of the Love Windermere Partnership, said:  

“A Changing Windermere is a vital resource in understanding the current condition of the lake and guiding future action.”  

“While we’ve seen positive changes, we must continue working together to address the challenges that remain. Through collaboration, investment, and science-led solutions, we can secure a healthier future for Windermere for generations to come.” 

Community Engagement Events 

To ensure the community can learn more about the findings and contribute to ongoing efforts, Love Windermere partners will be hosting a series of drop events across the Windermere catchment from 31 March. 

These events will provide an opportunity for residents, businesses and visitors to speak directly with experts, ask questions and discuss their connections with this iconic place.  

Find out more 

The report will help shape the Love Windermere Partnership’s upcoming Action Plan, due to be published in 2025. The plan will outline specific measures to address the key findings, including reducing nutrient inputs, mitigating the impacts of climate change, and promoting sustainable practices across the catchment. 

“A Changing Windermere” report, poster and postcard are now available to download from the Love Windermere website: https://lovewindermere.co.uk/a-changing-windermere/.