Introduction
The Bridgwater Tidal Barrier Scheme has secured legal approval and significant government funding to tackle the town’s long-term flood risk. Early works included ground investigations, archaeological and ecological surveys, all designed to integrate flood defences with local environmental and community improvements. Full construction began in early 2025.
While current floodwalls and banks provide temporary protection, events like the near-flood in 2014 show that tidal surges combined with high river flows pose a growing threat. As sea levels rise and defences age, a more robust, future-proof solution is needed which is why a tidal barrier was chosen.
Planning and design
Since 2014, the Scheme has undergone extensive planning, assessment, and public consultation. A range of options were considered, including raised walls, a tidal lagoon, and an exclusion sluice. After detailed evaluation of cost, environmental impact, effectiveness, and deliverability, a tidal surge barrier emerged as the best long-term solution.
Several locations were then explored using ground and archaeological investigations with the outcome on the more optimum location being between Express Park and Chilton Trinity for the following reasons:
- We had the greatest confidence of achieving the permissions for construction at this location and it is the most cost-efficient site.
- Our investigations have shown that the river channel is less stable in other locations, which makes it more difficult to predict the impact a barrier would have on the river and navigation.
- There are several access points available for construction, to help reduce disruption during the build.
- There is least risk of unpredictable siltation issues near Dunball Wharf, which would require costly maintenance dredging.
- The width of the river is relatively narrow, meaning the structure will be smaller and requiring less maintenance costs.
- It supports aspirations in Somerset Council’s Green Infrastructure Plan for a pedestrian and cycle bridge linking Chilton Trinity with Express Park with off road cycle paths and the Parrett Trail and SW Coastal Path.
The chosen design is a twin vertical lift gate which has:
- Proven reliability in a high silt environment
- Easier to maintain and replace than other barrier types
- Similar technology to other major sluices in Somerset
- Minimises whole life cost and operational carbon emissions
Transport and Works Act Order
A Transport and Works Act Order (TWAO) is a legal mechanism in the United Kingdom that grants statutory authority for the construction and operation of transport-related infrastructure projects. Established under the Transport and Works Act 1992, TWAOs are commonly used to authorise schemes such as railways, tramways, and certain inland waterways.
Purpose and Function
A TWAO provides the necessary legal powers to construct and operate specific transport projects. It can confer powers for the compulsory acquisition of land and rights over land essential for the project and can authorise works that may interfere with public or private rights, such as navigation rights on waterways.
Approval Process for a Transport and Works Act Order
- Application Submission – the project promoter submits an application to the relevant Secretary of State, detailing the proposed works and associated powers required.
- Public Consultation – the application undergoes a public consultation process, allowing stakeholders, including local communities and businesses, to provide feedback or lodge objections.
- Examination – depending on the nature and complexity of the project, a public inquiry or hearing may be held to examine the proposals and consider representations made.
- Decision – after considering all inputs, the Secretary of State decides whether to grant the TWAO, potentially with modifications or conditions.
Process Undertaken
In December 2019, the Environment Agency submitted a TWAO application to the Secretary of State for Environment, Food and Rural Affairs. The application was subject to public consultation, allowing stakeholders to review and comment on the proposals. This process ensured that local concerns and interests were considered. In March 2022, after thorough examination, the Secretary of State granted the TWAO, providing the legal authority to proceed with the construction and operation of the tidal barrier.
Securing the TWAO was a pivotal milestone for the Scheme, as it granted the EA the necessary legal powers to:
- Legally undertake the building and management of the tidal barrier.
- Temporarily close or restrict navigation on the River Parrett during construction and operation as required for safety and project needs.
- Compulsorily acquire land and rights essential for the project’s implementation.
This authorisation ensures that the project can proceed in compliance with legal requirements, balancing infrastructure development with the rights and interests of local stakeholders.
Construction
Overview
Contractor Kier already has several live contracts running on the Bridgwater Tidal Barrier Scheme, all awarded on the Environment Agency’s Construction Delivery Framework (CDF). This includes all the prelims, access roads, pile purchase and the construction of downstream flood defence embankments.
The next and final contract under the Southern Coastal Framework (SCF), the one we are evaluating at present, will be for the bypass channel, the barrier substructure, superstructure and operational control buildings, this is expected to be finalised in late 2025.
The sequence of construction will be; construction of the substructure, which includes the bypass channel and cofferdams; RC works; enabling works for the barrier; earth embankments and installation of culverts.
Our Approach to Construction
We are committed to working closely with local communities throughout construction to minimise disruption wherever possible. Many mitigations are already in place, such as haul roads, gates, and early enabling works to reduce impact.
We maintain open lines of communication with individual landowners, land users, and the wider community, sharing timely updates as the Scheme progresses.
On the Chilton Trinity side, a new access road has been built off Saltlands Lane (past the Recycling Centre) to reduce impacts on nearby villages such as Pawlett and Combwich. We continue to liaise with residents and parish councils to manage this.
Construction traffic will need to use local roads, but traffic management plans and safe working practices are being developed in consultation with the community.
Where possible, we are using locally excavated material from nearby borrow pits to build new flood embankments, reducing the need for HGV imports and helping to limit traffic disruption.
Site Access and Compounds
To minimise overall impact, construction access will be from both sides of the River Parrett:
- East bank: via Express Park and Heron Court
- West bank: via the NDR, Saltlands Lane, and the Sewage Treatment Works
In early 2023, a Western Access Track was constructed behind Saltlands Recycling Centre. Once construction ends, this will be repurposed into a cycle path linking Bridgwater’s industrial estate to the River Parrett’s bridleways.
Temporary compounds will be set up for materials and equipment. A permanent operational compound and control centre will be based at Express Park.
Temporary access routes will also be created off the A38 in Pawlett and via a private road in Combwich, but these will not be used post-construction.
Managing Noise and Vibration
Some construction activities will generate higher noise levels. We are carrying out ongoing noise and vibration monitoring on new activities, to ensure we remain within agreed limits set by planning permissions and the Transport and Works Act Order. Sound barriers are also in place in key areas to help protect nearby homes and businesses.
Kier’s core working hours are Monday to Friday 7am to 7pm and Saturday 7am to 1pm. This is apart from In Channel works which have permitted working hours between 5am to 8pm, Monday to Friday, Saturday and Sunday 7am to 8pm. This to allow working with the tides.
In Channel activity is work that happens in the channel, in this case once a by-pass channel has been created. This allows the River Parrett to be safely diverted around the construction site so we can build the barrier foundations in a dry and secure area. This is done by installing a cofferdam, a watertight enclosure that is pumped dry, which would not be possible without first providing a safe alternative route for the river. This also ensures continuity of flow for the river and protection of the local environment and river life while construction takes place. Once the barrier is complete, the river will be returned to its normal course, and the bypass channel will no longer be needed. More information on this approach can be found in our Community Response to Noise Disruption document.
You can also find further information below that explains the consented hours of working (see the Planning Directive Application document) and the noise monitoring that has been undertaken. In addition, the Community Response to Noise Disruption document below includes more detailed information and has been made available to local residents.
Mitigating environmental impact
Sustainability is at the heart of the Bridgwater Tidal Barrier Scheme. We are working to minimise waste, reduce carbon emissions, and reuse materials wherever possible.
Did you know?
Materials excavated and used on the Bridgwater Tidal Barrier Scheme are managed as efficiently as possible to reduce waste and lower the project’s carbon footprint. The scheme is committed to reducing waste and minimising its environmental impact through innovative materials management.
Reusing materials from other projects: Excess Riprap and Redi-Rock from neighbouring Environment Agency projects were repurposed at Bridgwater Tidal Barrier for scour protection and infill, cutting waste and carbon emissions.
On-site recycling: During site preparations at Chilton Trinity, remains of Victorian brick kilns were uncovered. Archaeologists recorded these finds and identified one kiln in good condition, which has been carefully protected beneath the main compound for potential future conservation. Other fragments and redundant material from the brickworks were recycled on site, avoiding landfill and reducing the need for new construction materials.
Zero waste to landfill: To date, 100% of non-hazardous waste from the project has been diverted from landfill.
Low-carbon site operations:
- Site welfare units are powered by solar, battery, and even hydrogen at our new main compound.
- An electric crane was used for early piling work to reduce emissions.
- We are exploring pre-cast concrete for the superstructure to further reduce carbon use on site.
These steps reflect our commitment to sustainability and innovation—supporting the delivery of critical flood defences with a lighter environmental footprint.
Find out more
You can find answers to the most frequently asked questions about the development of the barrier on our Development of the Bridgwater Tidal Barrier – your questions answered page.