United Utilities has launched a preliminary market engagement exercise for the upcoming procurement of a Design and Integration Partner for its Only Rainwater into Windermere (ORiW) programme with an estimated total value of £720 million including VAT.

The water company is inviting interested parties to attend a virtual Programme Launch Event that will be held on Thursday 29 October 13:30- 17:00 via Microsoft Teams. Attendees will be restricted to 2 individuals per supplier. Deadline to register interest to attend the event is 2pm on Tuesday 27 October 2026.

The water company is proposing to deliver a long-term, transformational programme - Only Rainwater into Windermere (ORiW), with the ambition of making Windermere the cleanest lake in England by removing discharges from both public and private sources, while also addressing highway runoff.

The programme is intended to protect the lake's ecology, water quality and amenity value for future generations with a target end state of "Only Rainwater into Windermere", restoring the lake as close as possible to its natural condition and reducing the risk of harmful algal blooms.

A coalition has now been established to develop and deliver the ORiW feasibility phase which brings together key stakeholders, including United Utilities , local authorities, regulators and environmental organisations, to provide strategic direction and has sponsored the commission of a ‘feasibility study’ to ascertain the art of the possible for achieving OriW.

Through the commission there are now feasible options for achieving the ambition, to improve water quality, and enhance the environmental resilience of the Windermere catchment, through a proposed ORiW system and wider infrastructure. The proposed ORiW system is made up of multiple workstreams;

• First Time Sewerage (FTS), connecting properties to the public sewer network that are currently outside of the network and have never previously been connected to it.
• First time Treatment (FTT), for the sites where FTS is not possible, a remote treatment solution will be implemented.
• Reduced weather dependent flow, surface water management and management and treatment of highways runoff through the use of nature- based solutions where possible across the catchment.
• Construction of tunnel and rising mains.
• Upgrade of an existing wastewater treatment works and discharge point.

United Utilities is anticipating that the ORiW system and the other strategic wastewater transfer and treatment infrastructure required for the ORiW programme (including the tunnel, rising mains, pumping stations, wastewater treatment facilities, associated drainage works and all ancillary infrastructure), will be promoted through a Development Consent Order (DCO) as a Nationally Significant Infrastructure Project (NSIP), subject to Section 35 approval by Defra.

Photo: Algal blooms on Lake Windermere

The water company will shortly be launching the competitive tendering procedure for the appointment of a Design and Integration Partner (D&IP) who will be responsible for supporting the next phase of this programme, designing the ORiW system, including whole system integration, to achieve the programme vision.

The D&IP will be required to complete feasibility, outline design, constructability and other related activities to obtain the necessary approvals and consents for the programme to proceed to the delivery phase for the preferred solution.

The appointed partner will also be responsible for the delivery of the DCO and planning approvals; as such, the outline design will need to fully support and integrate with the DCO, Town and Country Planning Act (TCPA) and land acquisition and access processes.

At a high level, the initial scope of requirements for the D&IP will include the following activities across each of the workstreams of the ORiW system:

• Outline design
• Planning, consents and land
• Environmental Impact Assessments (EIA) and surveys
• Stakeholder and customer engagement
• Land Agency, referencing and surveying
• Preparation and submission of planning applications and all supporting information
• Preparation and submission of the DCO and all supporting information
• Ground Investigation (GI) Early Contractor involvement (ECI)

United Utilities says supporting the company in meeting its reporting requirements with Ofwat will require a D&IP who has the capability and experience to ensure coordination over integration of all elements of the ORiW system and all other related activities that are required.

The D&IP will also need to be capable of leading the overall delivery strategy, managing interfaces across the programme, maintaining design consistency, and ensuring that the complete solution meets the requirements to obtain the necessary approvals and consents.

United Utilities is currently continuing to consider its approach to the delivery phase of the programme and anticipates that it may need ongoing support from the D&IP into the delivery phase to provide continuity throughout the programme lifecycle.

The precise form that this ongoing support may take will be dependent on the precise delivery model that the utility adopts, but this may include the following:

• The D&IP acting as system integrator and detailed design partner to either UU and/or any prime contractor engaged in relation to the programme.
• The D&IP acting as a system integrator partner to provide support across different workstreams and work packages forming part of the programme so that the overall programme is delivered as seamlessly as possible.
• Providing alternative services to support UU’s client-side management of delivery partners engaged to undertake the delivery phase of the programme.

United Utilities point out that it is also conceivable that the D&IP will not be required to provide any ongoing support during the delivery phase.

Anticipated value of each role is as follows:

• Design & Integration Partner (pre delivery phase) > 4 years = circa £60-100m
• System Integrator Partner (during delivery phase) > up to a further 9 years in increments at UUs discretion = circa £100m (subject to CPIH)
• System Integrator and Detailed Design Partner (during delivery phase) > up to a further 9 years in increments at UUs discretion = circa £500m (subject to CPIH)

The total value is given as a range (£60 million to £600 million) which includes the minimum and maximum total estimated values across those roles.

The system integrator partner (during delivery phase) and system integrator and detailed design partner roles are alternatives - the combined value of each is not included in the total (only the higher of the two).

Current estimated start and end contract dates are 1 April 2027 to 31 March 2031, with further possible extension options up to 31 March 2040.

United Utilities is now inviting interested parties to attend a virtual Programme Launch Event that will be held on Thursday 29 October 13:30- 17:00 via Microsoft Teams, to share further information about the ORiW programme and the D&IP procurement. Attendees will be restricted to 2 individuals per supplier.

Interested suppliers who would like to attend the event, are asked to provide further information and complete an online form. Click here to access the form.

Deadline to register interest to attend the event is 2pm on Tuesday 27 October 2026.

United Utilities may - but does not currently intend - to extend the market engagement activity to encompass other events or activities (including further virtual and in-person sessions as well as written engagement such as surveys and questionnaires).

Interested suppliers should ensure that they have registered using the means, and by the deadline, described above if they wish to be included in any further events or activities.

Current estimated publication date of a formal tender notice is 5 November 2026.

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