The global shift away from fossil fuels is essential to prevent catastrophic climate change, with nuclear energy often advocated as a low-carbon alternative. However, its environmental impact remains a significant issue of debate.
At Bristol Avon Rivers Trust (BART), we set aside the broader nuclear energy discussion to focus on a local but critical matter: EDF’s Hinkley Point C (HPC) and the company’s efforts to remove essential safeguards designed to protect marine life in the Severn Estuary including protected migratory fish species who need to access freshwater river catchments to fulfil their lifecycles.
Background on Hinkley Point C (HPC) and its Water Intake from the Severn Estuary
HPC’s reactors will rely on the Severn Estuary to cool them, drawing a staggering 132,000 litres of water per second, equivalent to an Olympic-sized swimming pool every 12 seconds, over the plant’s expected 70-year lifespan.
The intake is located in the Severn Estuary, a designated Special Area of Conservation (SAC), Special Protection Area (SPA), and Ramsar Site. This area serves as a vital migratory route for fish species crucial to the estuary’s biodiversity, including the endangered Atlantic salmon, twaite shad, and European eel. These species are also fundamental to the food chain, supporting tens of thousands of overwintering birds.
Required Mitigation Measures to reduce HPC’s Impact on Fish
EDF’s discharge consent for HPC, approved by the Environment Agency in 2013, included three essential mitigation measures designed to protect fish populations:
- An Acoustic Fish Deterrent (AFD),
- Low-velocity side intakes, and
- A Fish Recovery and Return system.
These measures that were proposed together as a “mitigation package”, were integral to EDF’s Development Consent Order (DCO) for HPC. These measures will only be effective if delivered together, as one without the other two would compromise the effectiveness of the mitigation.
EDF’s Effort to Remove the AFD – 1 of 3 key agreed mitigation measures
In 2019, EDF applied to remove the requirement of the AFD from the discharge consent order, citing challenges with installation, maintenance, and diver safety due to the Bristol Channel’s harsh conditions. This triggered a public inquiry, with a coalition of environmental organisations supporting the Environment Agency (EA) in opposing EDF’s proposal.
In August 2022, the UK Secretary of State for the Environment ruled in favour of the Environment Agency (EA), mandating that the AFD remain in place. Following the decision, EDF faced two options: either to install the AFD as required or to seek a legal route to remove the installation condition. They opted for the latter, pursuing a process under Article 6(4) of the Habitats Directive.
A recent coalition report, available at AFD Delivery Group, confirms that the AFD is both essential and feasible to implement.
Impacts of Removing the AFD on Fish
EDF estimates that the removal of the AFD would result in the death of between 1.89 million and 2.9 million fish annually over the next sixty years, according to data from the Centre for Environment, Fisheries and Aquaculture Science (CEFAS) in the HPC Consultation Overview Document Jan 2024 (top of page 15). In contrast, a report from the Welsh Government indicates that the removal of the AFD could lead to the death of at least 182 million fish each year for the same duration (The implications of Hinkley Point C for Wales’ environment and its people (gov.wales), top of page 15).
Simply put, removing the AFD compromises the effectiveness of the other two mitigation measures initially agreed upon, placing fish populations at significant risk. Without the AFD, the power plant’s intake tunnels could create a ‘reef effect’ and attract fish and other aquatic life, only to trap and draw them in the cooling system. Fisheries experts also warn that “fish recovery” is a misleading term, as most fish caught in the intake system—regardless of size—are unlikely to survive the nearly 4 km journey through the tunnels.
Insufficient Compensation for Fish and the Need for Effective Solutions
Estimates suggest that if EDF proceeds with its plans to remove the AFD, hundreds of millions of fish would be killed or injured annually over the next sixty years. This poses a considerable risk to vulnerable migratory species, including salmon, lamprey, eel, and shad, which travel into the Bristol Avon.
As part of a proposed further application to remove the AFD from the DCO, EDF is currently developing a “compensation package” to offset impacts, that includes saltmarsh creation, seagrass, and oyster beds, as well as fish passage improvements on the River Severn and select Welsh rivers.
BART and leading fisheries experts are concerned that EDF’s focus on saltmarsh creation and the other measures stated above, as a primary compensation method falls short in addressing the broader ecological impacts on migratory fish. Though saltmarshes provide environmental benefits, they do little to support migratory species like Atlantic salmon and twaite shad, which pass through the area impacted by the HPC intake to reach freshwater catchments.
BART advocates for a greater focus on river catchment restoration techniques, and particularly the removal of several key barriers which are currently limiting access to spawning areas for these migratory species, as a part of the package of compensation. The removal of these barriers or installing fish passes to open access to spawning habitats and support species’ lifecycles would play a particularly valuable role in protecting migratory fish numbers from the effects of the Hinkley Point C water intake in the Severn Estuary going forward.
BART is concerned that EDF’s limited river catchment compensation efforts are largely concentrated on the Severn and certain Welsh rivers, leaving the Bristol Avon—a recovering river supporting many of the species likely to be affected by HPC and closer to HPC —without immediate compensatory plans. Yet the Bristol Avon is a significant river in the lower Severn Estuary (at 75 miles in length compared to the Usk at 78 Miles, for example), and with the presence of Salmon recorded as spawning in its tributaries, ecologically, the Bristol Avon is very important when considering the rivers to be looked at for compensation works.
For Further Information:
For more information on the plight of migratory fish species, you can read these concerning articles:
BART’s Summary of Position on the AFD:
BART firmly urges EDF to revise its approach and refocus on getting on with the task of delivering the requirements of the DCO. This is vital to protect the ecological future of river catchments flowing into the Severn Estuary including the Bristol Avon. This includes installing the AFD and providing adequate compensation for species impacted by HPC’s operations, with compensation measures implemented before the power station becomes operational. This proactive approach is essential to mitigate the harm to fish populations that will result from the vast water abstraction from the Severn Estuary.
To summarise, BART’s stance on the proposed removal of the Acoustic Fish Deterrent (AFD) at Hinkley Point C (HPC) is as follows:
- The AFD should still be installed as originally planned.
- Compensation and mitigation are necessary, regardless of whether the AFD is installed.
- Compensation efforts should address all affected fish species.
- Saltmarsh restoration is highly valuable in its own right, but EDF’s inadequate engagement is undermining its perceived value to the public.
- While saltmarsh benefits some fish species, it does little for migratory species like Atlantic salmon, Sea trout, European Eel and Twaite shad.
- Although EDF’s compensation package includes fish passage easements for the Severn, Usk, and Wye rivers, it neglects rivers closer to HPC, such as the Bristol Avon.
