Liverpool City Region Combined Authority has proposed a preferred corridor for the Mersey tidal barrage between Bromborough on the Wirral and Otterspool in Liverpool. The authority announced the recommendation on 29 October 2026, with members due to consider it on 6 November. The decision has not yet been made, and it would not give permission to construct a barrage.
The proposed zone covers a 1.5-mile stretch of the estuary, embracing both banks. It is a location for further engineering and environmental work, not a final line across the river, a fixed design or confirmation of the eventual shore connections. Those details will matter to river users, nearby communities and protected environments as the proposal develops.
The announcement is significant because the Mersey tidal barrage could become a nationally important energy and flood-protection scheme. The promoter is considering up to one gigawatt of generation and a long operational life, but must still secure a Development Consent Order and an investment decision. Friday’s vote is an early project milestone, not consent or funding for construction.
Where is the Mersey tidal barrage corridor?
The Combined Authority’s 29 October announcement identifies the area between Bromborough and Otterspool as the preferred development zone. This follows an appraisal of possible positions and engagement with interested parties. The proposal covers a corridor about 1.5 miles long, rather than an approved structure whose final length and alignment have been established.
One important technical question is the relationship with commercial navigation. The authority says further work should examine ways to align a barrage alongside navigation channels, as well as alternatives involving locks. That is an acknowledgement that port activity, vessel movements and engineering practicality remain live design issues, not a finding that a particular layout has been settled.
For local people, the precise landfall sites, access arrangements, construction compounds and any new power connections may ultimately matter as much as the stretch of river identified today. The Mersey tidal barrage recommendation narrows the geographical options without determining those onshore impacts. Detailed plans, surveys and public engagement are needed before those questions can be properly answered.
What will members decide on 6 November?
The Combined Authority is due to consider whether to endorse the preferred alignment corridor at its Friday 6 November meeting. Members are also expected to consider a Regulated Asset Base funding model as the preferred financing approach. Neither recommendation is an issued planning permission, nor does an endorsement itself guarantee private or government investment.
A Regulated Asset Base arrangement can allow some infrastructure costs to be recovered from customers while a project is being constructed, rather than waiting for operation. The authority presents that model as a possible way to reduce financing costs. The precise arrangements, regulatory framework and any consequences for bills have not been settled simply by selecting a preferred model.
The 6 November report will therefore matter, but it should be reported in the correct sequence. A decision to continue design and commercial development would be different from approving a complete business case. The Mersey tidal barrage still faces further technical work, statutory consents and a final investment decision before construction could proceed.
A national infrastructure consent is still needed
The scheme is being advanced as a Nationally Significant Infrastructure Project under the Planning Act 2008. A Development Consent Order, commonly called a DCO, is the principal consent route. The authority says the project is in a development phase involving engineering, environmental assessment and preparation for an eventual application, not a scheme with an issued DCO.
For an explanation of how these large projects are assessed, see Planning Geek’s guide to National Policy Statements and nationally significant infrastructure. A DCO application is examined within a statutory system, with an eventual decision by the relevant Secretary of State. A local Combined Authority vote about preferred options cannot replace that process.
The promoter’s earlier public consultation information describes the potential main components, including turbines, water-control structures, navigation facilities, export cables and onshore operations. Those are concept elements, not the current approved layout. It would be premature to assume that every previously described component or programme date remains unchanged.
In October 2026 the authority says further community engagement is being planned for late 2027 or early 2028. Residents, businesses and estuary users will need clear information on how the evolving Mersey tidal barrage design affects particular places. Environmental assessment and the treatment of consultation responses are consequential steps, not formalities following a corridor announcement.
Energy generation and flood protection
The Combined Authority describes a potential capacity of up to one gigawatt and an operating life of 120 years. Those are ambition and design figures, not a measurement of electricity actually produced. Tidal generation depends on the movement of water and operating arrangements, so an installed capacity figure should not be read as continuous output.
Proposals have also evolved to give flood protection a more prominent place. The authority says updated Environment Agency flood mapping informed its decision to develop a dual-purpose project, with rising sea levels an important consideration. That creates possible benefits, but the design must demonstrate how flood risk would be managed without assuming that a barrier automatically solves every downstream or upstream problem.
The Mersey tidal barrage will also require scrutiny of estuary ecology, sediment movement, water levels, fisheries and habitats. Those issues cannot be disposed of by comparing the project’s claimed electricity capacity with national renewable energy targets. The environment in which a tidal barrage operates is part of the engineering challenge and the consenting balance.
What the mayor and communities have said
Liverpool City Region Mayor Steve Rotheram said in the authority’s statement: Identifying where the barrage could be built is a major step forward
. That accurately describes the stage reached, while leaving the subsequent design, consent and financing decisions open.
The authority reports that more than 3,000 responses were received during engagement in 2024, with substantial support for the principle of the project. Those survey results are part of the promoter’s account of an early exercise. They do not establish that every community or river user supports the specific Bromborough to Otterspool corridor, which had not yet been finally selected.
Independent coverage by Water Magazine on 30 October and Place North West on 2 November confirms the significance of the recommendation. Crucially, those accounts describe a future Combined Authority decision and DCO process; they do not report that the proposed barrage has received development consent.
What happens next for the Mersey tidal barrage?
The immediate milestone is the 6 November Combined Authority meeting. If members endorse the corridor and preferred funding model, the project team can continue investigating its design, navigation effects, ecology and commercial feasibility. Those findings may alter elements of the proposal before any application is submitted for national consideration.
The authority currently expects a final investment decision in 2030. That remains a programme expectation rather than a legally binding start date, and the promoter must first establish the scope, financing and consent position. Earlier indicative schedules should not be recycled as current deadlines without checking the latest project information.
For planning professionals, the real development is the proposed geographical narrowing of an unusually large infrastructure project. The Mersey tidal barrage has moved forward in project definition, but no one should mistake a preferred corridor for a fixed barrage, an issued DCO or guaranteed funding. The next reportable stage will be the actual 6 November decision, when the authority’s minutes and resolutions are available.
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