Proposed change to fish protection measures at Hinkley Point C

Full document title: Consultation Overview Document

Purpose of the document: Provides an overview of what is being proposed and gives details on how to respond and where to view the supporting documents to the consultation.

Document number: 100195841

View document

Full document title: Updated Environmental Statement

Purpose of the document: This document provides an assessment of the likely significant effects arising from the proposed change (not installing an acoustic fish deterrent system). It updates the assessment submitted with the original Development Consent Order application. It confirms that no significant environmental effects will be caused. It is prepared in accordance with the Infrastructure Planning (Environmental Impact Assessment) Regulations 2017.

Document number: NNB-308-REP-000723

View document

Full document title: Updated Report to Inform the Habitats Regulations Assessment

Purpose of the document: This document provides an update to the Habitats Regulations Assessment Report submitted with the original Development Consent Order application. It includes updated information, which confirms that the proposed change (not installing an acoustic fish deterrent system) will not have an adverse effect on the integrity of sites protected by the Conservation of Habitats and Species Regulations 2017 (Habitats Regulations). It is prepared in accordance with the Habitats Regulations.

Document number: NNB-308-REP-000722

View document

Full document title: Updated Water Framework Directive Compliance Assessment

Purpose of the document: This document assesses the proposed fish protection measures (without an acoustic fish deterrent system) and confirms that the design will continue to comply with the requirements of the Water Framework Directive.

Document number: NNB-308-REP-000725

View document

Full document title: Implications for Compliance with the Eels Regulations

Purpose of the document: This document assesses the suitability of the proposed fish protection measures (without an acoustic fish deterrent system) on the basis of compliance with the Eels (England and Wales) Regulations 2009 and Eel Management Plans.

Document number: NNB-308-REP-000746

View document

Full document title: Revised Predictions of Impingement Effects at Hinkley Point C – 2018 Edition 2 (Cefas)

Purpose of the document: This report underpins the above assessments and reports. It provides revised predictions of impingement arising from fish being entrapped in the cooling water system. This includes an updated baseline, taking into consideration newly available data, information and analysis techniques.

Document number: HPC-DEV024-XXX-000-RET-100031

View document

Full document title: Summary of Engineering Optioneering Process 2019

Purpose of the document: This report provides details of the engineering and design process undertaken to identify a suitable acoustic fish deterrent system. It includes an appendix containing an independent review of the health and safety studies and risk analysis undertaken to support the optioneering and design processes for an acoustic fish deterrent system: Bureau Veritas (2018) Acoustic Fish Deterrent Health and Safety Review. 

Document number: NNB-301-REP-000710

View document

Full document title: Hinkley Point C Cooling Water Infrastructure Fish Protection Measures: Report to Discharge DCO Requirement CW1 (Paragraph 1) and Marine Licence Condition 5.2.31

Purpose of the document: This report provides details of the cooling water system design as approved by the Marine Management Organisation, particularly the mitigation measures of the fish recovery and return system and intake head design which have been assessed in the Updated Environmental Statement.

Document number: NNB-209-REP-0001030

View document

Full document title: Chapter 19 Environmental Statement – Volume 2 (October 2011) Hinkley Point C Development Site: Marine Ecology

Purpose of the document: This chapter is an excerpt from the original Development Consent Order application which explains the assessments of impacts to the marine environment that were undertaken at the time NNB submitted the original Development Consent Order application. It summarises the conclusions on significance which were drawn from those assessments.

Document number: 100195927

View document

An acoustic fish deterrent uses sound to deter certain groups of fish (i.e. those with well-developed hearing) from the cooling water intakes. Only sprat and herring of the most common fish in the Bristol Channel have good hearing and they are abundant and not commercially fished. The deterrent is less effective for fish with less developed hearing and ineffective for some species.

Evidence provided by the governments marine and freshwater science experts, Cefas, shows that the operation of an acoustic fish deterrent system would have very little effect on protected fish species in the Severn Estuary. The number of fish killed per year could be equated to that of a small fishing vessel.

Installing and maintaining dozens of sound projectors underwater two miles offshore is also dangerous and poses risks to divers that are unacceptable. The Bristol Channel has poor underwater visibility and one of the highest tidal ranges in the world. 

As a result of these reasons, we have decided that it would not be appropriate to install an acoustic fish deterrent. Operating a system with negligible benefit for the environment would place a burden on future operators and endanger the lives of workers for decades to come.

Hinkley Point C, like all power stations, needs cooling water to generate electricity. The government’s marine and freshwater science experts, Cefas, predicted the percentage of adult fish stocks taken each year by the power station, just as they would for commercial fishing.

Very large numbers of fish are eaten by other fish, marine birds and porpoises. This natural mortality is typically 10 to 20% of the adult population per year for longer-lived species but 60% or more for shorter-lived shoaling species. Fishing can sustainably take at least 10% to 20% of the adult population every year without affecting the species' ability to reproduce and maintain their population levels. For many species higher levels of fishing are sustainable.

The worst case predicted effect of Hinkley Point C with the planned two fish protection measures in place varies by species, from a maximum of 0.4% to less than 0.02% per year. To put this into context, the total amount of fish estimated to be killed by the operation of HPC without the AFD system has been predicted by Cefas to be around 56 tonnes in a year - about the same as would be caught by one small fishing vessel.

Cefas concluded the predicted levels would have no effect on the sustainability of each species nor on the predators that rely on the fish to survive.

No - the total amount of fish estimated to be killed by the operation of HPC without the AFD system has been predicted by Cefas to be around 56 tonnes in a year - about the same as the annual catch of one small fishing vessel.

Cefas concluded that this level is limited when compared to natural mortality and fishing. The predicted levels will have no effect on the sustainability of each species nor on the predators that rely on the fish to survive.

All power station cooling systems using river or sea water have an impact on fish. Even with measures to protect fish, not all will survive the passage through the cooling tunnels. The fish return system is effective for more robust species.

The total amount of fish taken will be around 56 tonnes compared with 650,000 tonnes commercially fished in the UK each year by over 6,000 boats. So our impact will be equivalent to about a small trawler's catch per year.

Many power stations have taken cooling water from the Bristol Channel in the past with no detrimental impact on fish populations. Hinkley Point C will be the first to include any fish protection measures at all.

Some power stations have experimented with the use of acoustic fish deterrent systems in the past but there has been no use of long-term permanent systems.

It was regarded as emerging best practice when the original plans for the power station were drafted. Now that more detailed design work has been undertaken, Hinkley Point C has concluded that the deterrent does not provide significant environmental benefit and that its installation and on-going maintenance poses unacceptable safety risks to divers and workers.

Hinkley Point C will be the first power station in the Bristol Channel to have fish protection measures installed. The cooling water system includes low velocity side entry water intakes designed to minimise the number of fish taken into the system and a fish return system.

The Hinkley Point C cooling water intake system will take seawater direct from Bristol Channel before returning that same water back into the sea. Water will be taken through intake heads and tunnels 3.3km from the shore at a depth of 20m below the seabed. Once at the shore the water will go through a filtration system of coarse and fine mesh screens in a cooling water pumphouse. Fish will be returned to the sea via a fish return system.

We are now working with the Environment Agency, Natural England and Natural Resources Wales to develop a proportionate and robust compensation package to mitigate any impact of the removal of the acoustic fish deterrent system.

Typically, there are between seven and ten species that make up 95% of the fish found around Hinkley Point: European sprat, herring, whiting, sole, cod, thin-lipped grey mullet, flounder and 5 bearded rockling. Of these species only sprat and herring have good hearing, the others have average to poor hearing and are therefore less likely to respond to sound deterrents. Twenty fish species were included in the comprehensive assessment undertaken by Cefas. 

These migratory species do use the Severn Estuary but primarily use the main channel of the estuary they also swim near to the surface. They are not expected to be affected in any significant numbers as the water intake structuresare about 10km from the main channel and are near the bottom.