United Utilities is expected to open tenders in November 2026 for a design and integration partner on the Only Rainwater into Windermere Project. According to Construction Enquirer, the contract is worth up to £600m, with an initial design phase of around £60-100m. It forms part of a programme with a value currently estimated at £3.7bn.
Barbour ABI is currently tracking this project even at its earliest stages as this seven-year long project idles patiently at the Deplanning jetty.
What is the Only Rainwater into Windermere Project?
Only Rainwater into Windermere (ORiW) is a feasibility-stage programme to end all wastewater discharges into Lake Windermere.
The project would do this by intercepting treated and untreated wastewater across the catchment and sending it through a new network of tunnels and pipelines to enhanced treatment works away from the lake.
Overall, the network would total around 138km including 77km of new sewers that would connect roughly 12,800 people to public sewerage for the first time.
It will also intercept about 35km of highway run-off and install 37 hectares of sustainable drainage.
The programme’s feasibility report started with over 70 options but has narrowed to two preferred options ending either at Ulverston or the River Leven. Both take wastewater out of the catchment but they mostly differ in where it is treated and discharged and how much transfer infrastructure is needed. Each would cost between £3.6-3.7bn to build.
ORiW project intelligence from Barbour ABI
According to our team of in-house construction researchers, tender notice for the appointment of a design and integration partner is expected to be awarded in Q2 2027.
Planning documents are expected to be submitted in winter 2028.
A total of four clients have been assigned to the project so far, including:
- Environment Agency
- Lake District National Park
- United Utilities
- Westmorland & Furness Council
Consulting engineers consist of Jacobs Limited and Mott MacDonald. Both of whom are listed consulting engineers on the Thames Water – AMP8 Framework
Access Project ID 12944953 to view the full history of the project and to get updated timings of each phase of the project progresses.
Why does the ORiW project matter?
The project matters because Windermere is under growing ecological pressure. Long-term reporting shows declining deep-water oxygen and harmful algal blooms due to the vast amount of wastewater entering the lake.
According to reports by Save Windermere, six sewage overflow sites around the lake discharged for 33,410 hours between 2020-2024. For context, that’s nearly four years of continuous pollution.
Since the lake sits at the lowest point of its catchment, pollution accumulates in the lake. According to the feasibility report, “Water entering the lake can take upwards of nine months to make its way into the River Leven for the short dash to Morecambe Bay; whatever comes into the lake either stays there or has plenty of time to affect the chemistry and biology of this UNESCO World Heritage Site.”
Diverting all wastewater away from Windermere will clear harmful pollution, save local wildlife, and improve conditions for residents, tourists, and businesses.
Who will be funding the Windermere clean-up?
The project is still at very early stages so funding options have not been officially announced. It is speculated that the project could be funded through several AMP cycles 8-10.
We have covered other water infrastructure projects recently awarded within the AMP8 programme that are due to help solve storm overflow storage problems as well as phosphorus removals, treatment works upgrades, and more.
What is the Only Rainwater into Windermere Coalition?
ORiW is run by a coalition of the Environment Agency, the Lake District National Park Authority, Love Windermere, Save Windermere, United Utilities, and Westmorland & Furness Council.
In the foreword to the feasibility report, independent convener Edward Twiddy describes the project’s goal as:
“A future vision for Windermere that is fed only by the rivers, streams and springs that flow off the land is the goal of the Only Rainwater into Windermere project.”
Tracking the Only Rainwater into Windermere Project on Barbour ABI
Project, company, and role details for the ORiW project and all water infrastructure projects can be tracked on the Construction Project Leads Platform.
Clients of the platform can access this with Project ID 12944953. Search for other water infrastructure projects like reservoirs and AMP8 framework projects via our AI Search, Just Ask, or use our advanced filter search option to filter by project type, region, stage, frameworks, and more.
Because this project is still in a feasibility-stage at the time of this blog’s publication, we will be updating this project frequently.
If you’re not a client and would like to see who’s behind these large water infrastructure projects, you can request 10 free leads directly from our platform.
