Affinity Water and Severn Trent Water have taken a significant steps forward in the development of the Grand Union Canal Transfer scheme, a major new project aimed at bolstering water supply from the Midlands to Southeast England.

Affinity Water is engaging on delivery of the Grand Union Transfer itself, while Severn Trent is seeking feedback on plans for the Minworth Advanced Water Treatment Plant, which is associated with the scheme.

Grand Union engagement

Affinity Water has issued a preliminary market engagement notice, signalling the start of an early market consultation for this nationally significant infrastructure initiative, anticipated to be worth approximately £425M excluding VAT (£510M with VAT).

The Grand Union Canal Transfer is a collaborative effort involving Affinity Water, Severn Trent Water and the Canal & River Trust, the charity responsible for the upkeep of the canal network across England and Wales. The project seeks to leverage the existing canal infrastructure alongside new water treatment works, pumping stations, transfer pipelines and environmental mitigation measures to provide a more sustainable and reliable water supply. It also aims to reduce reliance on current sources, including vulnerable chalk stream habitats, while ensuring continued water availability for canal navigation.

The solution’s deployable output will be 50Ml/d by 2031/32, with the potential for a further 50 Ml/d by 2040-2050 if required. Flow will be transferred from Severn Trent’s new Advanced Water Treatment Plant at Minworth via a new pipeline over approximately 20km to a discharge point into the Coventry Canal. For much of its length, the transfer will flow along the existing canal network using gravity, making use of pumping stations and by-passes as necessary. The water will then be abstracted at Leighton Buzzard for treatment.

Diagram of Grand Union Canal Transfer

The Grand Union Canal Transfer, designated a project of national significance, will be delivered through Ofwat’s Direct Procurement for Customers (DPC) programme, which aims to introduce competitive delivery models for water infrastructure.

Affinity Water plans to appoint a Competitively Appointed Provider (Cap) through a Design-Build-Finance (DBF), Design-Build-Finance-Maintain (DBFM) or Design-Build-Finance-Operate-Maintain (DBFOM) model, or variations thereof. The chosen Cap will be entrusted with the design, construction and financing of the scheme, with potential responsibilities for long-term operation and maintenance under a contract projected to run from 30 September 2028 until 30 June 2057.

The issuance of the market engagement notice is a request for information, seeking to draw on expertise from infrastructure investors, construction and engineering firms, operations and maintenance specialists, as well as joint ventures or consortia. Affinity Water’s goal is to gauge market capability, understand potential delivery models and associated risks, and identify innovations that could enhance project outcomes. The feedback will be used to inform the procurement strategy and refine the commercial, technical, and delivery framework.

Key considerations outlined in the consultation include technical feasibility, financial structuring, operational requirements, risk allocation, environmental and regulatory factors, and any potential barriers to market entry. Affinity Water emphasises an open, fair and transparent competitive process, aiming to secure a value-oriented solution consistent with the long-term national objectives for water resilience.

The Grand Union Canal Transfer project represents a critical infrastructure advancement, responding to growing water demand pressures in the Southeast while emphasising environmental stewardship. It highlights an innovative approach that integrates traditional waterway assets with modern engineering and financing practices to foster sustainability and resilience in the UK’s water sector.

As this early stage of the scheme’s development, stakeholders and market participants will have the opportunity to contribute insights that shape a transformative water transfer scheme intended to serve millions and protect vital natural habitats for decades to come.

Severn Trent’s Minworth SRO

Severn Trent has also engaged the market on development of its Minworth strategic resource option (SRO), which could tie into the Grand Union Canal Transfer.

The Minworth SRO will encompass the construction of an Advanced Water Treatment Plant on Severn Trent’s existing Minworth site and transfer via an underground pipeline to an outfall into the Coventry Canal at Atherstone.

The utility company is engaging the market on a £200M contract to construct the SRO.

The estimate contract dates for delivery are 1 December 2028 to 1 December 2030.

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