Wonderful Windermere
Methodology Consultation

What is Wonderful Windermere?  

United Utilities aims to support the water quality, long-term resilience and heritage of Windermere, one of England’s most significant and iconic waterbodies, through the stewardship of catchment-wide solutions. 

In addition to the £200 million of planned investment, upgrading treatment standards at the catchment’s treatment works and creating extra storage capacity to reduce spills from storm overflows by 2030, we are looking to do more and utilise our experience of wastewater systems and innovative network management to help others.  

We are proposing to work with third-party assets, such as septic tanks and package treatment plants as well as agricultural land and other landowners, within the Windermere catchment to help improve water quality. There are several ways that assets can be improved, and first time sewerage is always an option that can be investigated. However, first time sewerage may not always be appropriate, or possible, therefore we have developed a bespoke performance commitment, known as Wonderful Windermere. 

How does this work? 

Through the Wonderful Windermere performance commitment, we are seeking to drive improvements related to phosphorus removal in Lake Windermere. We aim to do this through a range of actions which could improve the performance of third-party assets and help reduce the impact of other sources. 

To deliver this performance commitment, implement the relevant solutions and ensure that all improvements are measured, we have created a methodology document. The final methodology will be applied to the delivery of this performance commitment which runs to 2030.​ 

Consultation on key aspects of the proposed methodology 

We are seeking feedback on four keys areas of the methodology, including the sources used to provide improvements to phosphorous removal, the sampling, the modelling and governance regime. We are asking for your input and expertise to help us shape this performance commitment for the benefit of the Windermere catchment. This will allow us to understand feedback and refine the methodology based on your input. 

Consultation process 

We ask that you give us your feedback on the four key areas that we are reviewing within the performance commitment methodology. We will then collate this feedback and submit a final methodology to Ofwat which, once agreed, will be applied to the delivery of this performance commitment over the next 5 years. 

A copy of the methodology, an explainer of the performance commitment and the consultation form can all be found in the links below. 

Timeline 

• The consultation will close at 5pm on 13 June 2025​ 
• United Utilities will collate feedback and submit a final methodology to Ofwat by 1 July 2025