Ambleside is one of our flagship projects to improve water quality in Windermere. We’ve been investigating different options for storage to support our existing treatment infrastructure and further reduce stormwater spills to the lake.

Following on from our investigations over the past months, we’re proposing to build two new above ground storage tanks. The tanks would be 27m wide and 5m high, and would hold around 4,500m3 of water - that’s about the same as 2 Olympic size swimming pools. Over the past few months, we’ve been carrying out early site work, including trial holes, surveys and ground investigations around Miller Field to help us understand the site in more detail. The outcome of which has shown that our original proposal for an underground storage tank is extremely complex due to the challenging ground conditions which include areas of bedrock. As a result, we have been working with engineers and planners to develop an alternative above ground solution that would avoid major excavation and all the disruption that comes with this. Crucially, this would still deliver the environmental benefits we all want to see and up to 12 months sooner than originally planned.

Proposed timeline (*subject to change)

• August 2025 - Planning submitted
• November 2025 - Preparation works
• Spring / Summer 2026 - Main construction work begins
• 2028 - Planned completion expected

Carrying out the project considerately and safely

We understand that construction activity can be disruptive and our teams would do all they can to minimise impacts for the local community, road and car park users throughout the project.
Construction traffic There would be an increase in construction vehicles travelling to, and from the site. A traffic management and access plan would operate during the main construction period.

- Miller Bridge car park would remain in use as normal throughout our work Inbound construction traffic would access from Borrans Road via the A593 and use the existing entrance to Ambleside WwTW. A one-way system would be in place through the working area
- Outbound traffic would also be directed to join Borrans Road and head away from site, avoiding impacts to Ambleside town centre
- Designated route for oversized/abnormal vehicles with a holding area.Entry/exit via the Miller Bridge car park with priority given to car park users
- General staff vehicles would access the site offices via the main Miller Bridge car park entrance/exit route


Restoring nature

Once completed, we propose to replant woodland areas at the site. This is displayed on this map



Visualisation



Benefits

There are a number of benefits to our new proposal:

- Avoids major excavation which would be required for the construction of a below ground tank
- We are proposing to deliver a comprehensive landscaping scheme to help screen the tanks
- Minimises noise and vibration disruption
- Significant reduction in vehicle movements due to not needing to excavate the area and a reduction in amount of concrete required
- This solution allows for the continued operation of Parkrun during construction and operation, on diverted routes
- Delivers the environmental benefits 12 months sooner than a below ground solution

Building on decades of investment

Over the last two decades, we have invested millions of pounds upgrading our wastewater treatment sites, pumping stations and sewers in and around
Windermere.

Over the last five years we have:

- Introduced larger capacity pipes to cope with extra development
- Upgraded wastewater treatment works and utilised the latest treatment technology
- Halved the amount of phosphorus entering Windermere from our sites since 2015
- Delivered a 15% reduction in the amount of phosphorus entering Windermere from wastewater treatment, improving water quality and by using industry leading treatment capability
- Increased capacity of the sewer to Tower Wood, which had reduced the spill numbers from over 200 to less than 30, further reducing impact on the environment and water quality