Windermere discharge removal feasibility study

Between July and December 2023, a team of 15 engineers from multiple disciplines carried out a feasibility study to assess options to remove all discharges from the Windermere catchment in a comparable way to that achieved at Lake Annecy in France. 

Read more about the study here 

While it accounts for known factors such as topography and areas of ecological importance, the study is conceptual and includes a theoretical route for a new sewer system as well as a new treatment works at Grange-over-Sands.

Key considerations include an assessment of the impact that such a scheme would have on local communities, tourism, businesses and the local environment in this area of the Lake District National Park.

A proposed route was developed applying several principles to mitigate the impact of the scheme as far as possible.

The study has two elements:

• Development of a high-level solution to move flows collected by the public sewer network from the Windermere catchment to a new, notional, downstream location at Grange-over-Sands, via a theorised 67km (42 miles) of new network. This includes both treated wastewater and water from combined storm overflows.

• Development of a high-level solution to collect all remaining private sewage facilities, including 1,800 septic tanks, via an estimated 330km (205 miles) of additional network within the Windermere catchment and connect them to the theorised sewer network.

While both options are high level, they provide an indication of the scale of work involved. Developing a detailed proposal for a scheme of this magnitude would require further in-depth investigation.

This study was carried out as a contribution to the local interest being shown in a Lake Annecy type model for Windermere involving the removal of all discharges into the lake. We would be happy to participate in any further work.