18 Terrestrial Ecology
18 TERRESTRIAL ECOLOGY
18.1 Introduction
18.1.1 This chapter of the EnvApp examines the potential impacts on terrestrial ecology and features of nature conservation interest within the Development Site and the surrounding area, during the construction and operational phases of the Hinkley Point C. Where required, mitigation measures have been identified to prevent, reduce or offset potential impacts.
18.2 Scope of Assessment
18.2.1 A key issue in assessing the effects of any development on ecology and biodiversity conservation interests is to define the areas of land cover and the species and habitats that need to be considered. In defining these, two inter-related factors need to be considered:
a development can affect habitats and species directly (e.g. the land-take required) and indirectly (e.g. through disturbance), the impacts potentially extending beyond the development site boundaries; and it is impractical for an ecological assessment to consider every individual species and habitat that may potentially be affected, rather it should focus on ‘valued ecological receptors’, i.e. species and habitats that are valued in some way (e.g. designated sites, species protected by specific legislation or species which have economic value) and which could potentially be affected by the proposed development. 18.2.2 The scope of this assessment has been defined through preliminary desk study, extensive ecological surveys and a formal scoping process. This approach accords with the requirements of The Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 1999 - SI No. 293, which only require likely significant effects to be assessed. 18.2.3 The initial scope of the ecological work was defined following a detailed desk study conducted in early 2007. An ecological scoping report was produced which was circulated to consultees, and agreement was subsequently sought from organisations such as Natural England, the Somerset County Council Ecologist, RSPB and Somerset Wildlife Trust that the scope of the proposed ecological work was appropriate. Following these initial surveys and definition of the site boundary under the Strategic Siting Assessment (SSA) further consultation was undertaken to define and agree the scope of additional ecological work required to inform the EnvApp.
18.3 Legislation and Policy
a) International Legislation 18.3.1 Most international biodiversity legislation, e.g. the Bonn and Berne Conventions, is implemented through European or domestic legislation. The exception to this is the Ramsar Convention (1971) which addresses the conservation and wise use of wetlands, full account of which has been taken in this assessment.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 1 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology b) European Legislation 18.3.2 The assessment takes account of the requirements of, or advice given in, the following legislation:
The Birds Directive (1979); The Habitats Directive (1992); and EC guidance documents on implementation of the Habitats Directive. c) National Legislation 18.3.3 The assessment takes further account of the requirements of, or advice given in, the following:
The Conservation of Habitats and Species Regulations (2010). These Regulations succeed the original Conservation (Natural Habitats, &c) Regulations (1994) and consolidate all the various amendments made to the 1994 Regulations in respect of England and Wales (herein referred to as the ‘Habitats Regulations’); The Wildlife and Countryside Act (1981), as amended; The Natural Environment and Rural Communities [NERC] Act (2006); The Hedgerow Regulations (1997); and The Protection of Badgers Act (1992). d) Policy 18.3.4 The principal policy documents addressing biodiversity that are relevant to the proposal are:
Planning Policy Statement (PPS) 9 (2005): Biodiversity and geological conservation, and associated guidance documents; West Somerset Local Plan (2006); The UK Biodiversity Action Plan (UKBAP); The South-west Biodiversity Implementation Plan (SWBIP) (1997); Wild Somerset: the Somerset Biodiversity Strategy 2008-2018; The West Somerset (Draft) Local Biodiversity Action Plan (WSBAP); and The (Draft) South West Regional Spatial Strategy (particularly Policy Env 4) (Ref. 18.1).
18.4 Methodology
a) Summary of Approach 18.4.1 The methodology for undertaking the terrestrial ecology component of the impact assessment has been based on guidelines produced by the Institute of Ecology and Environmental Management (IEEM 2006) (Ref. 18.2). This section starts with a description of how the baseline has been described and evaluated followed by a discussion of how future trends in this baseline have been predicted, how environmental measures incorporated into the scheme have been identified, and finally the workings of the process of assessing the significance of the residual effects of the scheme. b) Site Boundary Evolution 18.4.2 The site boundary has changed markedly during the course of the ecological studies conducted to inform the DCO application to the IPC. For clarity, and in order to understand the evolution of the scope of the different studies, this is discussed briefly below: 18.4.3 Initial ecological desk study, consultation and scoping began in early 2007, and was based on an area of land identified by British Energy as having the potential to accommodate nuclear new build. Terrestrial ecology surveys were initiated in March 2007 and focused on a site boundary covering an area of 84ha with an approximate central grid reference of ST207460. Less than
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology half of this land area was under British Energy’s land ownership, and since full access was only available within this land ownership boundary, survey outside it was undertaken from the extensive local network of Public Rights of Way (PRoW). 18.4.4 Following the leasing of land surrounding the British Energy land holding by EDF Energy in 2008, higher resolution surveys were initiated in this area. The completion of the takeover of British Energy by EDF Energy in January 2009 resulted in the survey schemes being amalgamated. The site boundary was subsequently redefined and enlarged to establish the ‘Strategic Site Area’ put forward as part of the Government’s Strategic Siting Assessment (SSA) process. Survey work on this revised site area was conducted from March 2009 onward and covered an area of approximately 206ha. c) Scoping Process 18.4.5 Prior to formal scoping for the EIA, a provisional scope of the ecological assessment was determined through a desk-based study. Consultation was conducted throughout the course of the baseline survey work, but was intensified as development proposals were defined and the potential effects of the development identified. A summary of the ecology specific consultation undertaken is provided in Table 18.4.1. Table 18.4.1: Summary of Consultation
Organisation Date of Meeting(s) Primary Subject of Meeting
Natural England 07/06/2007 Scope of Ecological Surveys
05/03/2008 Scope of EIA (multi-disciplinary meeting)
28/04/2009 Badger mitigation, preliminary works, survey results
22/06/2009 Survey scope for 2009, results of surveys in 2007 and 2008, mitigation
23/07/2009 Badger mitigation and licensing
07/10/2009 Results of 2009 surveys
27/10/2009 Badger mitigation and licensing
07/12/2009 Results of survey work; mitigation and other environmental measures
Somerset County Council 28/04/2009 Badger mitigation, preliminary works, survey results
22/06/2009 Survey scope for 2009, results of surveys in 2007 and 2008, mitigation
27/10/2009 Results of 2009 surveys
07/12/2009 Results of survey work; mitigation and other environmental measures
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18.4.6 The net result of this consultation and desk study exercise was a scope that encompassed the following:
Consideration of how the development could affect statutory sites designated for nature conservation, i.e. the Severn Special Protection Area (SPA), Special Area for Conservation (SAC) and Ramsar Site, and the Bridgwater Bay Site of Special Scientific Interest (SSSI) 1; Consideration of effects on non-statutory sites designated for biodiversity conservation, in particular the Hinkley County Wildlife Site (CWS); Assessment of impacts on protected species, taking account of appropriate mitigation strategies; Assessment of impacts on habitats and species of principal importance for conserving biodiversity in England; Assessment of impacts on habitats and species listed on the West Somerset Biodiversity Action Plan; Consideration of effects on ancient woodlands, veteran trees and habitat networks; Consideration of cumulative impacts and; The identification of opportunities for habitat creation/enhancement. d) Baseline Information Collection Methodology 18.4.7 The information used to describe the baseline conditions for the study area and inform the assessment has been collected from a combination of a desk-based study and field surveys. The initial desk-based study used the following sources:
Information from British Energy (including Annual Land Management Reports, the West Hinkley Wind farm Environmental Statement [Dulas Ltd, 2006] (Ref. 18.3), and previous planning submissions relating to Hinkley Point C); A history of the birds of Somerset (Ballance, 2006) (Ref. 18.4); Somerset bird reports (Somerset Ornithological Society, various dates) (Ref. 18.5, 18.6, 18.7); The Decommissioning EnvApp for Hinkley A (Magnox, 2006) (Ref. 18.8); The National Biodiversity Network Gateway website (http://data.nbn.org.uk/); National survey data such as the Environment Agency’s Fourth Otter Survey of England and Wales 2000-2002 (Wessex Region) (Ref. 18.9). Contacting various local and national organisations for information on designated sites and protected species; and Protected species information was requested from Somerset Environmental Records Centre (SERC). The desk-based study was based on a search area extending to 3km from the development site boundary (Ref. 18.10). 18.4.8 The desk-based search area was extended to 10km with regard to bats (following the completion of the first year of work) in order that records of individual rare species could be put into wider context. 18.4.9 A search area of 3km was considered too limited for statutorily protected sites, particularly for those designated for their ornithological interest (i.e. for species that may demonstrate significant mobility between sites). For this reason, the search area was extended to 5km to include locations and qualifying features of Special Protection Areas (SPAs), Ramsar Sites and Sites of Special Scientific Interest (SSSIs).
1 Effects on the Blue Anchor to Lilstock Coast SSSI fall outside the scope of this assessment as this is an entirely geological designation.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology 18.4.10 The organisations and individuals contacted during the desk study and the information received is found in Table 18.4.2. Table 18.4.2: Organisations and Individuals Contacted for Baseline Data
Organisation/Individual Data Requested Data Received
Natural England General biological information Contextual information received on with follow up specific request nocturnal bird studies undertaken in for invertebrate records other parts of the county, and on invertebrates on Wick Moor (adjacent to SSA). Invertebrate paper forwarded.
RSPB Contextual information Paper on bird use of Bridgwater Bay and Steart Area. General contextual information
Somerset Badger Group Badger records within the SSA As requested boundary
Somerset Bat Group Bat records (and queries with No additional data to that received regard to grey long-eared bat from SERC records) Correspondence with Edward Wells with regard to specific queries.
Somerset Environmental Biological records, non- As requested Records Centre (SERC) statutory site information within 3km of the SSA boundary. Requests in both 2007, and in 2009 following an extension to the site boundary
Somerset Ornithological Bird information for the SSA and As requested Society a 3km perimeter area
Somerset Otter Group Otter information for the SSA As requested and surrounding area
Somerset Reptile & Reptile and amphibian No data received Amphibian Group information relating to the SSA and a 2km perimeter area Repeat contact made
Somerset County Biological information Great Crested Newt Records Ecologists Information on bovine tuberculosis
Somerset Wildlife Trust General biological information Referred the biological data request relating to the SSA to SERC.
Vincent Wildlife Trust Biological records relating to No data or comment received the area and invitation to engage in consultation process Repeat contact made
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 5 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology e) Extended Phase 1 Habitat Survey 18.4.11 An initial Extended Phase 1 Habitat Survey was conducted in March 2007. This covered the eastern development land and a perimeter area 750m in width around it. As such the original survey took in the full extent of the finalised Development Site. A higher resolution survey of the land within the built development area west was conducted in August and September 2008 to refine the baseline for this area; and following the definition of the SSA boundary, a further Phase 1 survey was conducted in May 2009 to ensure high resolution data was gathered for the entire Development Site and to both update and fill in any gaps in coverage from the previous two years of work. Refer to Volume 2, Chapter 12; Figure 12.1. 18.4.12 The Wick Moor component of the Bridgwater Bay SSSI was also surveyed in detail in 2007. The survey was conducted using public rights of way (footpaths, bridleways and roads). All areas of the Development Site were surveyed in 2009. 18.4.13 Survey work was based on the Phase 1 habitat survey methodology (JNCC, 2003) (Ref. 18.11). Distinct habitats were identified and mapped, and any features of biodiversity conservation interest were subject to a more detailed description in a target note. As the standard Phase 1 habitat survey methodology is, in the main, concerned only with vegetation, the survey was extended to allow for the provision of information on other ecological features, particularly to identify the presence/potential presence of legally protected species and interest features such as hedgerows and water-bodies, requiring assessment in detail. 18.4.14 The Extended Phase 1 Survey Area is shown on Figure 18.1. f) Hedgerow Survey 18.4.15 All hedgerows considered to be at least 30 years old within, or forming the Development Site boundary were assessed against the requirements of The Hedgerows Regulations (1997). 18.4.16 Hedgerows within the built Development Area West and Bridgwater SSSI were initially surveyed in 2007, with a complete survey of hedgerows in the whole of the Development Site undertaken in May 2009. 18.4.17 The Hedgerow Regulations provide criteria against which the historical and ecological importance of hedges can be assessed. During this survey (the survey area is shown in Figure 18.1) only the ecological importance of each hedge was assessed, not the archaeological importance (see Chapter 22, Volume 2 of the EnvApp) which also forms part of the Hedgerow Regulations assessment. Hedgerows classified as being of ecological importance meets one or more of the following criteria:
it contains at least seven woody species in a 30m stretch; it has at least six woody species in a 30m stretch and at least three features (see below); it has at least six woody species in a 30m stretch and the presence of native black poplar (Populus nigra), small leaved lime (Tilia cordata), large leaved lime (Tilia platyphyllos) or wild service tree (Sorbus torminalis); it has at least five woody species in a 30m stretch and four features; or there is an adjacent bridleway or footpath, at least four woody species in a 30m stretch, and two features. 18.4.18 Features referred to above include the following:
a bank or wall along at least half the length of the hedge; an intact hedge; one standard tree per 50m of length; three valuable ground flora species; a ditch along at least half the length of the hedge;
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good connections with other hedgerows; and a parallel hedge within 15 metres. g) Woodland Condition Survey 18.4.19 To complement the Extended Phase 1 Survey undertaken in 2007, a woodland condition survey was conducted in May 2009. This involved a detailed assessment of the height, naturalness, structure and diversity of each woodland compartment within the Development Site (see Figure 18.1), a review of management history, and the production of a higher plant species list for each area of woodland. 18.4.20 Woodland antiquity was considered based on both field characteristics and the Ancient Woodland Inventory (which allows the determination of whether a woodland was present prior to 1600AD). Historical maps were also used to determine whether individual woodland compartments were present between 1887 and 1904, with British Energy land management reports referenced for recent management history. 18.4.21 During the field surveys, a list of the plant species present in the ground flora, understorey and canopy layers of the woodland was compiled, with notes taken on dominant species. This information was used to compare the woodland plant communities present within the Development Site with those described in the woodland section of the National Vegetation Classification (NVC) (Rodwell, 1991) (Ref. 18.12, 18.13) An NVC Survey was not undertaken as the Extended Phase 1 Habitat Survey indicated that the woodlands were likely to be of limited botanical interest and secondary origin. Notwithstanding this, the work allowed the woodlands to be attributed to an NVC community. Information regarding the structure of the woodland, the presence of other habitat types within woodland compartments and adjacent land use was also recorded. h) River Corridor Survey 18.4.22 A river corridor survey was completed for each watercourse within and immediately adjacent to the Development Site following the guidance provided in the River Corridor Surveys – Conservation Technical Handbook (NRA, 1992) (Ref. 18.14). 18.4.23 Watercourses were surveyed on 20th July 2009. During the survey, information was gathered on the physical and biological features of the aquatic, marginal, bank and adjacent land zones of each channel in order to characterise the watercourse. Undertaking a river corridor survey in addition to the Extended Phase 1 Habitat Survey allowed a more detailed record to be made of vegetation and also the presence and condition of physical features such as culverts and bridges. i) National Vegetation Classification (NVC) 18.4.24 In 2007 a NVC survey was conducted for three grassland compartments identified as being of potential botanical interest during the initial Extended Phase 1 Habitat Survey. All were within the Hinkley County Wildlife Site. 18.4.25 As a result of revision to the Development Site boundary in 2009, an additional area of semi- natural habitat was included within the potential development area, as was a further area of farmland to the south of the initial site footprint (See Volume 2, Chapter 1; Figure 1.1). The updated Extended Phase 1 Habitat Survey identified further areas of potential botanical interest within these extension areas, and NVC surveys were carried out of two areas to the south of the built development area (one characterised by scrub with scattered grassland and the other by more open grassland) and two areas of semi-natural grassland on the farmland in the Southern Construction Phase Area (one of which had grown within the confines of a young plantation and the other in a field on the Holford Stream). The ditch forming the south-eastern boundary of the Development Site (adjacent to Wick Moor) was also subject to detailed survey.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 7 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.4.26 Following the standard NVC methodology, a total of ninety-three quadrat samples of the vegetation were taken from within the Development Site. Eighty-two quadrats were taken from grassland compartments and eleven from the boundary ditch. The NVC survey areas are shown on Figure 18.1. j) Birds i) Breeding Bird Survey 18.4.27 Territory mapping surveys based on the British Trust for Ornithology (BTO) Common Bird Census (CBC) methodology were carried out in areas within 1km of the Built Development Area West (excluding the built nuclear plant) in 2007. These surveys therefore covered the entire Development Site (see Figure 18.2). 18.4.28 Within the Built Development Area West and on the SSSI (Wick Moor), transects no further than 50m apart were walked across for all open habitats. All field boundaries, the edge of the small reedbed and the edge of the small belts of semi-natural woodland were also walked (see Figure 18.3). Outside of the above areas, access during the 2007 survey was restricted, and surveys could only be conducted from public footpaths and bridleways, roads and tracks. Despite limited access to areas, sufficient area was covered by the survey work to enable characterisation of the wider breeding bird community to be undertaken. 18.4.29 While eight to ten visits are the standard for CBC sites being monitored over the long-term, where territory mapping is being used for the purpose of assessing potential environmental impacts it is generally accepted that three to four visits are sufficient to determine the numbers and densities of breeding birds with reasonable accuracy. Four survey visits were therefore undertaken on the following dates:
10 & 11 April 2007; 23 & 24 May 2007; 13 & 15 June 2007; and 19 & 21 July 2007. 18.4.30 Supplementary records and information of birds recorded outside timed surveys were also used when compiling the final territory map. 18.4.31 The breeding bird survey area is shown in Figure 18.2. ii) Barn Owl Survey 18.4.32 The initial desk study indicated that barn owls had been recorded in the area, although there was no evidence that breeding had occurred within or close to the Development Site within the last 20 years. Nevertheless, given that a number of agricultural barns that had the potential to support breeding barn owl were present within the Development Site boundary (see Figure 18.2), a survey was conducted. 18.4.33 It was not possible to complete an internal inspection of the barns within the Development Site as a structural assessment concluded that they were not safe to access without remedial work first being undertaken. An inspection of the barns using a pole mounted camera was therefore conducted in September 2009 to search for evidence of barn owl occupancy (such as splash, pellets and feathers). The survey was undertaken after barn owl young would have fledged and dispersed, but field signs of the species are obvious and the barns have not been in recent agricultural use, a fact which would help to preserve any signs if present. 18.4.34 Dusk and dawn emergence and re-entry surveys primarily aimed at determining whether bats were roosting within any of the barns were conducted in June and July 2009 (one survey [either dawn or dusk] was undertaken at each building in each month). Surveys typically began approximately 15 minutes before dusk or dawn and lasted for between 105 and 135 minutes.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology Toms et al (2000) (Ref. 18.15) concluded that in good weather conditions, surveying a structure for an hour before sunset and for an hour after gives a 97% chance of recording any barn owl that may be present. The surveys thus covered a substantial proportion of this optimal survey window. 18.4.35 A barn owl survey of the buildings was previously undertaken in conjunction with the West Hinkley Wind Farm application, and several bat surveys of the buildings (undertaken between 2005 and 2007 inclusive) have also been completed (during which any incidental sightings of owls would have been noted). iii) Intertidal and Inshore Marine Bird Survey 18.4.36 In order that any potential disturbance effects on birds using the intertidal areas and inshore marine waters adjacent to or in close proximity to the SSA boundary could be evaluated, surveys were undertaken between April 2007 and March 2009 inclusive using five observation points, located at the following OS Grid References:
Location 1 at ST19131 45837; Location 2 at ST19923 46162; Location 3 at ST20838 46284; Location 4 at ST21468 46318; Location 5 at ST21786 46088. 18.4.37 These locations, and the areas surveyed from them (Count Sectors) are shown on Figure 18.4. All waders, wildfowl and seabirds flying over the intertidal area and the inshore waters up to 500m from the shore were systematically recorded. The distance of 500m offshore from each location was selected as the maximum threshold for standard recording on the basis that all relevant bird species within this distance were generally identifiable in normal sea states and weather conditions, and accurate and comparable counts could therefore be made. It was also considered likely that any potential disturbance effects would be most likely to affect birds occurring in relatively close proximity (i.e. < 500m) from the proposed power station. The entire expanse of mud in Count Sector 5 was generally systematically recorded meaning that in this area that low water counts extended to 700-800m from the observation point. 18.4.38 Numbers and apparent behaviour of all species were noted and their position in relation to the survey location estimated and marked on to a field map. 18.4.39 The aim of the survey work was to record the numbers, diversity and activity of birds present and to identify areas of importance for birds (in the intertidal zone and inshore marine waters) throughout the tidal cycle. On each survey day, work was conducted over six full hours, so that any changes or patterns in bird distribution across the tidal cycle could be identified. During each hour of survey, the intertidal area and inshore waters within each count sector were scanned using binoculars for 45 minutes, and all species present or commuting through were recorded. There was then a ten to fifteen minute break in survey, to allow the surveyor to rest his eyes, walk between survey locations and regain focus before the next survey commenced. 18.4.40 In 2007/08 the level of survey effort was very high, with 8-12 visits conducted during each month. In April 2007, and between August 2007 and February 2008 inclusive, a total of 12 days of survey work were conducted during each month. Survey effort was reduced to 9 days in May 2007 and to 8 days (per month) during June and July 2007 reflecting the more limited use of the estuary by the majority of species forming the cited interest of the designations (SPA/Ramsar) during these periods. Adverse weather resulted in 11 rather than 12 surveys being conducted in March 2008. In 2008/09, following consultation with RSPB, survey intensity was further reduced. Between April 2008 and March 2009 inclusive, surveys were conducted during each of the first four weeks of each month.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 9 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.4.41 Between November 2008 and August 2009 inclusive, two supplementary high tide and two low tide counts were conducted each month across a survey area stretching between the coast north of Lilstock in the west (OS Grid Reference ST171454) and Penning Island in the east (OS Grid Reference ST285470). The area between Lilstock and the operational power stations at Hinkley was walked, while birds to the east of the power stations were recorded from two locations, one at Stolford (OS Grid Reference ST231460) and one around the central (coastal) point of Steart Flats (OS Grid Reference ST261454). High and low tide counts were conducted to standard WeBS methodologies. The survey area covered during the work is shown on Figure 18.5. This survey was of relatively low resolution in comparison to the intertidal surveys outlined above, and its principal value was to provide further data for areas remote from the Development Site that might be affected by the thermal plume from the cooling water outfall, and to supplement the existing WeBS data for the area. 18.4.42 In order to identify any significant concentrations of birds (particularly bird species listed as part of the qualifying interest of the Severn Estuary SPA/Ramsar) that might be using fields within or adjacent to the Development Site for foraging, loafing or roosting, field-by-field (walkover) surveys were undertaken during daylight hours within approximately 1km of the Built Development Area West. This survey area covered the entire Development Site plus the terrestrial part of the Severn Estuary Ramsar site and SPA, and Bridgwater Bay SSSI. 18.4.43 Surveys were carried out as instantaneous counts that recorded a snapshot of the birds present within each field at the time it was surveyed. The surveys involved scanning each field from a suitable local vantage point and recording the birds within it. Each field was given a unique identification number, which was logged onto a recording sheet during each survey, together with details of the species seen, their numbers and activity (e.g. foraging, loafing, roosting, etc.). The habitat and crop types in each of the fields in which birds were seen were also recorded on each visit in order to identify bird/habitat associations. Although all species were recorded during the surveys, particular emphasis was given to the following:
Any species cited in the Severn Estuary Ramsar and SPA or Bridgwater Bay SSSI descriptions, either as assemblage species, or for their internationally or nationally important winter or passage populations at these sites (Ref. 18.1); UK BAP species, all of which are now listed as species of principal importance for biodiversity conservation under Section 41(1) of the Natural Environment and Rural Communities Act (2006)2; Local (West Somerset) BAP species3; Species of conservation concern (BoCC Red or Amber Listed species) 4; EU Birds Directive Annex 1 species not covered in these categories; All other wader species;
2 The Secretary of State for Environment, Food and Rural Affairs was required under Section 41(1) of the Natural Environment and Rural Communities Act (NERC) 2006 to prepare a list of the species and habitats considered to be of principal importance for the purpose of conserving biodiversity in England. Under Section 41 of the Act, government committed to consultation with Natural England in determining the species and habitats to appear on the list, and committed to take steps (where they are reasonably practicable), and promote the taking of steps by others, to further the conservation of the habitats and species on the list. The Section 41 list replaces the list published by Defra in 2002 under Section 74 of the Countryside and Rights of Way (CRoW) Act 2000. Planning Policy Statement 9 (PPS9) refers to the steps that local authorities should take through the planning process in relation to species and habitats of principal importance. The current list of species of principal importance is found at http://www.defra.gov.uk/wildlife-countryside/biodiversity/sect41-nerc.htm 3 The only bird species listed on the 2008 draft of the West Somerset BAP is the long-eared owl. 4 The revision of the red and amber lists of birds of conservation concern (Eaton et al., 2009) (Ref. 18.16) has resulted in 1 breeding species being upgraded to the red list (cuckoo) and two more downgraded to the amber list (reed bunting and bullfinch). A further species that occurs within the Development Site predominantly during the passage and winter periods (and does not breed), lapwing, has also been added to the red list.
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All other wildfowl species (swans, ducks and geese); and Flocks of 50 or more birds of any other species (e.g. wintering passerines). 18.4.44 The field identification numbers and survey area for the daytime field surveys are shown in Figure 18.6. Each month, a full audit of habitat and crop types within each field was carried out using a predetermined set of habitat/crop type categories, with further categories added during the survey if necessary. The predetermined habitat/crop types were: ‘Ploughed’, ‘Winter-sown Cereal’, ‘Brassicas’, ‘Pasture’, ‘Horse Paddocks’, ‘Set-aside’, ‘Cereal Stubble’, ‘Rough Grassland’, ‘Woodland5’ and ‘Scrub’.’ This enabled bird activity to be linked to both broad habitat type (e.g. arable or pasture, woodland or scrub) and also to management regime. 18.4.45 Field surveys commenced in September 2007. Following the October 2007 survey (and consultation with RSPB) the frequency of visits was increased to four per month. Surveys then continued at this frequency until March 2009. iv) Nocturnal Bird Surveys 18.4.46 Nocturnal bird surveys were included within the scope of the baseline work at the request of Natural England. The aim of these surveys was to establish whether there was any nocturnal use of coastal fields during the winter period (December to February), particularly in the Wick Moor area. Wick Moor, may at times be seasonally inundated and thus provide suitable habitat for waterfowl and waders (roosting and foraging). 18.4.47 These nocturnal field surveys involved scanning the fields using night vision equipment. Surveys followed a predetermined route chosen to cover the coastal development area adjacent to the shoreline, the upper intertidal zone, and Wick Moor area. In addition, a series of vantage- points (which included the five coastal survey locations used during the daytime intertidal surveys) were used to collect further data, with the surveyor stopping at each vantage point to scan for several minutes (long enough of the visible area to be systematically scanned several times). During each survey, the numbers of each bird species and the number of the field in which they were present were recorded, together with the activity of the birds (e.g. foraging, roosting, etc.). The route used during the nocturnal surveys is shown on Figure 18.7. 18.4.48 Due to the limited effectiveness of even the most sensitive night vision equipment, nocturnal visits were generally carried out within a week of full moon to increase the chance of there being a good level of background light. During good background light conditions more extensive foraging occurs at night by some species, potentially making them more detectable. 18.4.49 Prior to at least one of the nocturnal surveys each month, a field survey was undertaken. This enabled the observer to identify areas that had recently become inundated (and therefore might be good areas for waterbirds) and feeding areas that were being used in the day that might also be used at night. The surveyor had the freedom to amend the route in response to the findings of these surveys. In the event, however, the same approximate route was followed during each survey, as field use was very limited and the key areas for birds were all on the route of the transect. 18.4.50 Surveys were conducted on a twice-monthly basis between December 2007 and May 2008 and between August 2008 and March 2009 inclusive.
5 Woodland was not targeted for survey, although areas of young plantation (such as the young broad-leaved plantation in the southern part of the Development Site were surveyed, as the sward structure in pre-thicket stage woodland is often suitable for foraging raptors including Schedule 1/Annex 1 species.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 11 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology k) Mammals i) Bats 18.4.51 Bat activity surveys were conducted during summer and autumn 2007, in September 2008 and between May and September 2009. A winter roost assessment (predominantly of trees although buildings were externally assessed) was completed in early 2009. These included monthly walked transects, emergence and re-entry surveys of buildings and woodland compartments containing trees with roosting opportunities. Two static Anabats (bat activity data loggers) were deployed continuously at a range of locations around the Development Site, trees with roost potential were climbed and inspected, and buildings were subject to internal inspection using a pole mounted camera. This latter activity was overseen by a licensed bat worker to ensure that any potential roosts were not disturbed. All survey work was based on Bat Conservation Trust Guidance (2007) (Ref. 18.17). 18.4.52 The bat survey transects, the positions of the Anabats, the areas in which tree climbing was completed and the position of surveyors for dusk and dawn emergence and re-entry surveys of buildings and trees in 2009 are shown on Figure 18.8. Walked and driven transects in 2007 are shown on Figure 18.9 and walked transects from September 2008 on Figure 18.10. ii) Water Vole (Arvicola terrestris) 18.4.53 An initial dedicated survey of water features within the Built Development Area West was conducted on 16th August 2007 to identify signs of water vole within areas of habitat identified as suitable during the Phase I habitat survey. All the water features present within the land and a 50m perimeter area were surveyed to determine likely presence/absence of the species. A survey of all water features in the Built Development Area East was conducted in September 2008. Further surveys of all watercourses and ponds were then conducted over 3 days in May 2009 in order to provide a full overview and update to the previous studies (see Figure 18.11). 18.4.54 The methodology for all surveys followed guidance provided in the Water Vole Conservation Handbook (Strachan & Moorhouse, 2006) (Ref. 18.18). This included searching for the following:
Latrines - comprising a concentration of droppings in discrete locations, often near nest sites, at range boundaries or often used places to enter and exit the water; Feeding stations - comprising neat piles of chewed lengths of vegetation, usually up to 10cm in length, on pathways or haul-out platforms adjacent to the waters edge; Burrows - these are typically found along the waters edge and on top of the bank (up to 5m from the waters edge) and are 4-8cm in diameter. Holes on top of the banks often have ‘lawns’ around them (areas of grazed vegetation); and Footprints - located in soft mud or silt. iii) Otter (Lutra lutra) 18.4.55 A dedicated survey of watercourses within the Built Development Area West was conducted on 16th August 2007 to identify signs of otter. All the water features present within the survey area and a 50m perimeter area were surveyed to determine likely presence/absence of the species. This work was extended and updated in 2009 with all water features within the Development Site and a 30m perimeter area being surveyed. 18.4.56 During the 2009 surveys, a small number of the larger watercourses up to approximately 5km from the Development Site boundary (in line with guidance provided in the Design Manual for Roads and Bridges, 2001) (Ref. 18.19) were surveyed for otter (see Figure 18.12). Watercourses selected were either connected to those water features within or adjacent to the Development Site, such that they could form good commuting corridors for otters, or had accessible features that comprised likely sprainting sites (e.g. bridges).
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology 18.4.57 During the survey the following signs, indicating the presence of otter, were searched for in the vicinity of the watercourses (as described in Chanin, 2003) (Ref. 18.20a):
Spraints - which are often located on prominent features within the channel or on the bank (e.g. bridges, rocks etc); and Footprints - located in soft mud or silt. 18.4.58 Additional evidence of otter presence such as the remains of dead fish or potential holt or resting up places were also searched for, although in isolation these signs can be difficult to attribute to otter rather than other species, such as mink. 18.4.59 The potential for holt or resting sites and commuting routes from other watercourses in the surrounding area (particularly from the River Parrett) passing along the watercourses at Hinkley was assessed by means of the field survey, consultation and desk study. iv) Dormouse (Muscardinus avellanarius) 18.4.60 Dormouse surveys of the Built Development Area West were initiated in 2007 (following the completion of the Extended Phase 1 Habitat Survey and the initial desk study), and were continued in 2008 and 2009. As a result of the survey it was concluded that some of the woodland and hedgerow within the Built Development Area West supported a relatively diverse range of species and had fairly complex structural diversity. Also, despite the woodland blocks being fairly isolated from each other, the network of hedgerows within and around the Development Site was thought to offer suitable habitat corridors between the woods on-site and to further areas of woodland off-site. 18.4.61 Further survey of woodland and hedgerows within the Built Development Area East were undertaken in autumn 2008, and continued throughout 2009. An additional survey was undertaken in 2009 to cover the remainder of the Development Site (see Figure 18.13). 18.4.62 The survey methodology followed guidance and context provided by the following publications:
Dormouse Nest Tubes (Mammal Society leaflet, undated) (Ref. 18.21); The Dormouse Conservation Handbook (English Nature, 2006) (Ref. 18.22); The Dormice (The Mammal Society, 1992) (Ref. 18.23); Surveying dormouse using nest tubes etc (English Nature Report No. 524 - Chanin & Woods) (Ref. 18.20b); and A Practical Guide to Dormouse Conservation (The Mammal Society, 1989) (Ref. 18.24). 18.4.63 Dormice construct nests during the summer, usually made out of strips of honeysuckle bark woven with leaves. These can occur almost anywhere within a dense hedge or woodland but are usually off the ground in scrub or trees and can be within holes in trees. This habit of nest building is used to survey for the presence of dormouse. This is achieved by providing suitable places for dormice to build their nests (in the form of wooden boxes and/or plastic tubes), which are then checked at regular intervals. 18.4.64 Dormouse tubes were first installed in late May and early June 2007, with further tubes deployed in August and September 2008 and in April 2009. In 2007 a total of 100 tubes were placed in suitable hedgerows and woodlands within the Built Development Area West. The tubes were checked monthly between June and November 2007. 18.4.65 In 2008 and 2009 the survey area for dormice was extended, with the scrub to the south of the existing plant, Branland Copse, two additional areas of woodland and mature hedgerows such as those along the east-west Green Lane and Benhole Lane being targeted for survey. In total, an additional 270 dormouse nest tubes were deployed in these areas. 18.4.66 During the dormouse nest tube surveys, other signs of dormice were also searched for, e.g. nests and feeding remains.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 13 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology v) Badger (Meles meles) 18.4.67 The initial Extended Phase 1 Habitat Survey recorded evidence of badger activity throughout the survey area. This determined that detailed badger surveys were required, and these were initiated during the following winter. Further survey work was undertaken in 2009 to ensure coverage of the entire Development Site and to update the baseline. 18.4.68 The Built Development Area West and the adjacent SSSI were systematically searched for badger setts in February 2008. Each sett identified was classified according to the criteria used in the National Badger Surveys (Cresswell et al, 1990., Wilson et al, 1997) (Ref. 18.25). The level of activity at each sett entrance hole was also classified. 18.4.69 To determine the number of social groups within the Built Development Area West and SSSI, a bait marking study was then undertaken. This study followed the method recommended by Delahay et al. (2000) (Ref. 18.26). Marked bait was fed to each sett for 12 days between 20th February and 10th March 2008 inclusive. 18.4.70 To maximise the number of badgers finding and eating the bait, it was distributed around each sett at 25 bait points (shallow pits in the ground created up to a distance of 15-20m from the outer sett entrances), that were covered with a tile or stone to protect the bait from the rain and to reduce the amount consumed by non-target species. For the first few days of feeding, bait was also dropped down the active sett entrances to encourage interest in it. Bait was replaced at each visit. It was placed in the afternoon to limit its exposure to other animals before badgers could locate it, but sufficiently early to avoid disrupting badger emergence. During each visit a note was made of the number and location of bait points that had been used to ensure sufficient bait uptake was taking place and that these did not need to be repositioned. 18.4.71 A search for badger latrines was undertaken during the bait marking study period. On 11th March 2008 (i.e. following the completion of feeding), all of the latrines were examined for the presence of plastic pellets within badger faeces. 18.4.72 The systematic survey and bait marking exercise was repeated using the same methodologies in March and April 2009 to cover the entire Development Site and to update the baseline for those areas previously surveyed (see Figure 18.13). The survey area included a perimeter zone around the Development Site of at least 200m width (in all but a northerly (seaward) direction) to gain information on social groups outwith and on the edge of the boundary but potentially using the Development Site for foraging. l) Amphibians and Reptiles i) Great-Crested Newt (Triturus cristatus) 18.4.73 Following an initial desk study in 2007 to identify pond locations, surveys of Pixie’s Pond (Pond 1), within the Built Development Area West were undertaken. In 2009, the desk study was repeated and all the ponds identified as being within approximately 500m of the Development Site boundary were visited (or revisited) to determine if they still existed, and if so whether they were likely to support great crested newts. This process incorporated the Habitat Suitability Index (HSI) developed by Oldham et al (2000) (Ref. 18.27), which provides a score of the suitability of a pond to support great crested newts and is a recognised tool for highlighting ponds with the greatest potential to support this species. 18.4.74 Key pond features, additional to the HSI assessment, that were considered in the screening exercise included:
receiving discharge of pollutants at excessive levels or containing anoxic waters; insufficient aquatic vegetation or other material that could be used for egg laying; extreme levels of fish activity (e.g. an intensively managed fishing lake) or waterfowl activity
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology (where the number of waterfowl present exceeds 10 per 1000m2; links to fast flowing streams, or the presence of an extreme management regime; and the lack of suitable connecting features e.g. mature hedgerows, ditches or woodland between the pond and the site that newts could follow or a significant barrier to movement between the pond and the development area. 18.4.75 Following screening, presence/absence surveys were carried out at any pond that was considered suitable for newts. Each pond was visited four times within the optimum survey period (mid-March to mid-June, English Nature Guidelines 2001) (Ref. 18.28), during which at least three methods of surveying were employed as follows:
bottle-trapping; torch-light surveying; and egg searching. 18.4.76 In 2009 a total of seven ponds were surveyed of which three were within the SSA boundary and a further four were in the wider area (within 500m of the SSA boundary, see Figure 18.14). One pond, just under 300m west of the SSA boundary (close to Knighton Farm) could not be effectively surveyed. It appears to be an old quarry, is of unknown depth and has very steep sides which are shrouded by thick bramble, making it inaccessible. The dominance of duckweed on the surface of the water also made ‘torch light surveying’ ineffective. m) Reptiles 18.4.77 Surveys for reptiles were conducted in 2007, 2008 and 2009. These initially concentrated on the coastal fields in close proximity to the operational power stations, but were extended to other potentially suitable terrestrial habitats such as the margins of the east-west Green Lane, the mosaic of habitat to the south of the existing power stations and discrete areas of suitable habitat in the southern part of the Development Site. 18.4.78 Successive Phase 1 habitat surveys and subsequent walkover surveys highlighted that much of the land within the development Site was likely to be poor for reptiles as the large, open, agricultural fields provide little cover and restrict foraging opportunities. However, some of the bases of the established hedgerows and small areas of rough grassland were identified as potentially suitable. The best reptile habitat within the Development Site was identified as the mosaic of habitats between Pixie’s Mound and the sewage treatment works. 18.4.79 Survey work conducted over the three years followed the methodology outlined in Froglife’s Advice Sheet 10 (Froglife, 1999) (Ref. 18.29) and took into account additional guidance provided by the Herpetofauna Workers’ Manual (JNCC, 2003) (Ref. 18.30) and Reptiles: guidelines for developers (English Nature, 2004) (Ref. 18.31). 18.4.80 Artificial refugia, comprising a range of different sized (minimum of 0.5m x 0.5m) roofing felt, were laid out in locations considered to have the highest potential to support reptiles, namely the hedgerow bases, woodland edges and areas of rough grassland during the successive surveys and away from public areas (e.g. footpaths) to minimise potential disturbance. A total of 539 refugia were deployed across an estimated area of 52.4 hectares of potentially suitable habitat, equating to 10.3 refugia per hectare. The survey area is shown in Figure 18.15). 18.4.81 During the survey period, refugia were checked on seven different days. April, May and September are considered to be the best times of the year to survey for reptiles (Froglife, 1999) (Ref. 18.29) as the cooler weather encourages the refugia to be used more extensively. Surveys therefore focussed on these months. 18.4.82 In instances where reptiles were recorded, the survey effort was then increased to 20 visits in order to derive a population estimate and to allow the importance of the area to reptiles to be evaluated thoroughly.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 15 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.4.83 Froglife (1999) (Ref. 18.29) guidelines set out a method for obtaining a population class size for reptile species, based on the maximum number of adults recorded on a single survey visit over a period of 20 survey visits. This also forms part of the criteria for the selection of Key Reptile Sites. Table 18.4.3 below summarises the method used for calculating class size. The numbers in the table refer to maximum number of adults seen by observation and/or under tiles (placed at a density of 10 per hectare), by one person in one day. Table 18.4.3: Classification of the Reptile Populations
Species Low Population Good Population Exceptional (Score 1 point) (Score 2 points) Population (Score 3 points)
Common lizard < 5 5 – 20 > 20
Slow worm < 5 5 – 20 > 20
Adder < 5 5 – 10 > 10
Grass snake < 5 5 – 10 > 10
18.4.84 To qualify for the Key Reptile Site Register a site must meet at least one of the following criteria:
it supports three or more reptile species; it supports two snake species; it supports an exceptional population of one species; it supports an assemblage of species scoring a total of at least four points; or the site does not satisfy the above criteria but is of particular regional importance due to local rarity. 18.4.85 This population class assessment is also used to quantify any subsequent mitigation required, such as the recommended duration of any translocation exercises that may be necessary, as detailed by the Herpetofauna Groups of Britain and Ireland (HGBI, 1998). A population class assessment as outlined above was only carried out for Area 3 (see Figure 18.15), as the initial survey results indicated that this area could qualify as a Key Reptile Site. n) Invertebrates 18.4.86 An initial walkover survey by an experienced invertebrate ecologist, and an extensive desk study were conducted in August 2008. The intention of the walkover was to assess the potential of the Development Site and its habitats for invertebrates, and gauge any requirement for more formal survey work. 18.4.87 Freshwater invertebrate survey was undertaken in September 2008. The unnamed watercourse that issues at ST197456 was subject to kick sampling and sweep netting at four points along its length. A further four sample sites (located on ponds and ditches) which lacked sufficient (or any) flow for kick sampling were subject to sweep netting. Kick sampling and sweep netting were both conducted for one minute intervals during this initial investigative work. 18.4.88 In 2009, the 2008 survey was extended to cover all watercourses within and adjacent to the Development Site including Bum Brook, Bayley’s Brook and the watercourse on the northern side of the Bridgwater Bay SSSI (see Figure 18.16). Sampling took place on 27 May and 19 June. All the watercourses were sampled with a standard pond net (1mm mesh bag) for 3- minutes by passing the net along the banks and over the beds of the shallower ditches. The contents were washed and sieved on the bank. Large freshwater invertebrates were identified in situ, with smaller material preserved in 10% formalin and retained for examination in the lab
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology under a binocular stereo-microscope. Other environmental parameters recorded included pH, conductivity and water temperature using a Hanna HI 98129 handheld meter. 18.4.89 Terrestrial invertebrates were predominantly surveyed by sweep netting. Selected invertebrates were removed using a pooter (aspirator), and taken away for further examination. Conspicuous species such as butterflies and adult dragonflies were identified in the field. 18.4.90 More ad hoc survey involving direct searching was undertaken of flower-heads, stones were turned over and plant galls and leaf mines searched for. o) Assessment Criteria 18.4.91 The assessment of the significance of predicted impacts on the potential ecological receptors is based on both their conservation value and the nature and scale of the effect (which is quantified where possible). i) Valuation of Receptors 18.4.92 The approach used to evaluate the potential biodiversity conservation receptors in terms of their policy importance has been adapted from IEEM guidelines on ecological impact assessment (IEEM 2006) (Ref. 18.2). 18.4.93 A key consideration in assessing the effects of any development on flora and fauna is to define the areas of habitat and the species that need to be considered. In identifying these receptors, it is important to recognise that a development can affect flora and fauna directly (e.g. the land- take required) and indirectly, by affecting land beyond the development site (e.g. through noise generation or hydrological impacts). The approach that has been undertaken throughout this EIA process, including at the earlier scoping stage, is to identify ‘valued ecological receptors’. 18.4.94 The value of species populations and habitats gives consideration to:
The importance in terms of ‘biodiversity conservation’ value - which relates to the conservation of representative areas of different habitats and the genetic diversity of species populations, and is often reflected in policy through their inclusion in Biodiversity Action Plans and national lists of priority species and habitats; The legal status – which is generally but not exclusively related to, biodiversity value; and Any social or economic benefits that species and habitats deliver. 18.4.95 For the purposes of this assessment, both species’ populations and habitats have been valued using the following scale:
International/national (UK); Regional (South-west region6); County (Somerset)7, district (West Somerset8); Local or parish (Stogursey Parish9); and
6 The South-west Biodiversity Implementation plan, which is available through the website (http://www.biodiversitysouthwest.org.uk) covers the south-west region, which includes Somerset (as well as Devon, Dorset, Gloucestershire, Wiltshire, Cornwall and the Isles of Scilly). As such there is ecological data available and targets have been set for this biogeographical region. 7 There is currently no Somerset BAP. The approximate area of Somerset (derived from www.magic.gov.uk) is 3,621km2/362,100ha. 8 There is a draft biodiversity action plan for West Somerset. This can be found at the following location http://www.ukbap.org.uk/lbap.aspx?id=485. The area of West Somerset is approximately 235km2 or 23,600ha accounting for approximately 6.5% of the area of Somerset. 9 This covers an area of approximately 33.36km2/3,336ha (derived from www.magic.gov.uk), of which approximately 9.25km2 (925ha) comprises intertidal habitat. The parish therefore accounts for approximately 14% of the District of West Somerset.
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Less than local/less than parish (sometimes referred to as a local zone of influence). The criteria applied to this scale is provided in Table 18.4.4. 18.4.96 The approach taken for this assessment is that a species population that is considered to be of county or greater importance in biodiversity conservation terms is considered to be a valued ecological receptor. A habitat considered of district or greater importance in biodiversity conservation terms is also considered to be a valued ecological receptor10. Where habitats or species do not meet these threshold levels11 they are not considered to be valued ecological receptors in the context of the Development and as a result likely significant effects (in EIA terms) would not arise. 18.4.97 It should be noted that in respect of species, the approach of this assessment is to consider the value of the survey area for the species under consideration, rather than the biodiversity conservation importance of the species itself. For example, while great crested newt as a species could be considered to be of international value by virtue of being listed on Annex IV of the Habitats Directive, the value of a site with a small number of ponds supporting a small population of newts would be more limited, and depending on the local abundance of the species might be realistically valued at any level between district and regional in terms of conservation importance. Table 18.4.4: Definition of Terms Relating to Nature Conservation Importance of Species and Habitats
Value Definition
High (International/ National) A species or habitat which forms part of the cited interest of a Ramsar Site, SPA or SAC. A regularly occurring population of Internationally important numbers of a species e.g. >1% of the international population. A nationally designated site e.g. SSSI, or a site considered worthy of such designation; Non-cited species or habitats which contribute to the integrity of a Ramsar Site, SPA or SAC. The regular occurrence of a nationally important number of a species (>1% of UK population) A viable area of a habitat type listed in Annex 1 of the Habitats Directive or smaller areas of such habitat which are essential to maintain the viability of a larger whole;
10 The exception to this is if the species population or habitat has been identified as having a high social value (e.g. an open space that is used extensively for informal recreation by local people, where the area’s wildlife is a major contribution to this value) or economic value or if the species is legally protected. 11 The selection of a lower threshold for habitats reflects the fact that habitats are important for the communities of plants and the assemblages of animal species that they support, and that they may also have a function in terms of linking other habitats. A district threshold therefore captures a very wide range of species as well as the land cover on which they and potentially other species, on nearby linked sites depend. However, this does not capture all important species populations, given the fact that some such populations occur on sites/habitats that are of below district value. In this context, it is considered that the county threshold will ensure that the Environmental Statement assesses effects on all species, for which effects could be material to the determination of consent relating to the scheme.
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Value Definition
The regular occurrence of a population of a species listed on Annex 1 of the EU Birds Directive, Annex II of the Habitats Directive and/or Schedules 1, 5 or 8 of the Wildlife and Countryside Act 1981 A regularly occurring population of an internationally important species (listed on Annex IV of the Habitats Directive or Annex I of the Birds Directive). Ecologically sensitive species such as rare birds (<300 breeding pairs in the UK) and the less common birds of prey (e.g. golden eagle, honey buzzard, osprey, marsh harrier and hen harrier) or rare and vulnerable migrant species that warrant special consideration because of the proximity of migratory routes or breeding, moulting, wintering or staging areas in relation to the development. A feature identified as of critical importance in the UKBAP.
Medium (Regional/County) A site that has been designated at the regional or county level e.g. the Hinkley County Wildlife Site or is considered worthy of such designation. A regularly occurring breeding, passage or wintering bird species that occurs in numbers that exceed 1% of the regional or county population The infrequent occurrence of a population of a species listed on Annex 1 of the EU Birds Directive, Annex II of the Habitats Directive and/or Schedules 1, 5 or 8 of the Wildlife and Countryside Act 1981 Non-cited species or habitats which contribute to the integrity of a SSSI. A regularly occurring, locally significant number of a nationally important species. Viable areas of key/priority habitat identified in the LBAP, or smaller areas of such habitat which are essential to maintain the viability of a larger whole.
Low (District/Parish) Areas of internationally or nationally important habitats which are degraded and have little or no potential for restoration; A good example of a common or widespread habitat in the local area. A regularly occurring, locally important population of a species that is not of significance at the EIA level. A species or habitat identified on the West Somerset Biodiversity Action Plan, but not under any of the legislation or lists of species and habitats considered above.
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Value Definition
Negligible (Less than Parish) Areas of heavily modified or managed vegetation of low species diversity or low value as habitat to species of nature conservation interest; Common and widespread species.
ii) Legal Protection of Species 18.4.98 Notwithstanding what has been said above, there is also a need to identify all legally protected species that could be affected by the proposed Development in order that measures can be taken to ensure that contravention of the relevant legislation is avoided. This may include the adoption of suitable mitigation measures agreed with the relevant authority, in this case, Natural England. iii) Prediction of Trends 18.4.99 Once the value of the site has been assessed it is necessary to consider possible future trends in the status of these habitats and species in order to attempt to predict whether the site, in the absence of development (but with a continuation of current land-use), would experience any change in value in biodiversity conservation terms. This is done by examining information on local and national trends in species where known (such as published trends in bird species), and considering any species or habitat action plans within the UKBAP and the West Somerset BAP and for which medium or long term quantitative or qualitative changes in habitats or species have been identified. Such changes could result in the future ecological value of the undeveloped site increasing or decreasing. iv) Nature and Scale of Effect 18.4.100 Ecological receptors are usually sites, habitats, species assemblages/communities or populations or groups of a species. Effects can be permanent or temporary; direct or indirect, and can be cumulative. Temporary effects can be short term (i.e. lasting only for one season/generation) medium term (i.e. lasting for more than one year/generation but less than ten) or long term (i.e. lasting for more than ten seasons/generations). Wherever possible, the scale of the impact has been quantified. These factors are brought together and professional judgement is used to assign the magnitude to one of four classes (see Table 18.4.5) of the impact on those ecological receptors selected for assessment. Table 18.4.5: Definition of Effect Magnitude for Terrestrial Ecological Receptors
Magnitude Definition
High A permanent or long-term effect on the integrity of a site or conservation status of a habitat, species assemblage/community, population or group. If adverse, this is likely to threaten its sustainability; if beneficial, this is likely to enhance its conservation status.
Moderate A permanent or long-term effect on the integrity of a site or conservation status of a habitat, species assemblage/community, population or group. If adverse, this is unlikely to threaten its sustainability; if beneficial, this is likely to be sustainable but is unlikely to enhance its conservation status.
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Magnitude Definition
Low A short-term but reversible effect on the integrity of a site or conservation status of a habitat, species assemblage/community, population or group that is within the range of variation normally experienced between years.
Very Low A short-term but reversible effect on the integrity of a site or conservation status of a habitat, species assemblage/community, population or group that is within the normal range of annual variation.
No change No change from baseline situation
18.4.101 With respect to the definitions provided in Table 18.4.5, ‘Integrity’ is the coherence of the ecological structure and functions of a site or habitat that enables it to sustain its plant and animal communities and populations. 18.4.102 Conservation status may be defined differently for habitats and species (IEEM, 2006) (Ref. 18.2):
for habitats, conservation status is determined by the sum of the influences acting on the habitat and its typical species, that may affect its long-term distribution, structure and functions as well as the long-term survival of its typical species within a given geographical area; and for species, conservation status is determined by the sum of influences acting on the species concerned that may affect the long-term distribution and abundance of its populations within a given geographical area. v) Significance of Effect 18.4.103 The significance of an effect is largely a product of the biodiversity conservation value of the ecological receptor and the magnitude of the effect on it, moderated by professional judgement. The matrix that has been used for guidance in the assessment of significance is given in Chapter 4, Volume 2 of the EnvApp. As a general guide, effects of moderate or greater significance are considered to be significant in EIA terms.
18.5 Baseline Environmental Conditions
a) Current Conditions i) General Site Description 18.5.1 The Development Site comprises open, gently rolling mixed lowland farmland with hedgerows of variable quality, small scrubby woodlands and occasional standard trees. Much of the area is intensively managed, and there is little semi-natural habitat present away from the cliff edge and the immediate vicinity of the existing power stations. 18.5.2 A relatively extensive area of land on the southern side, and small areas of ground to the east and west of the existing built nuclear plant have been subject to management by British Energy. This has been implemented through a land management plan; initiatives have included the mowing and harrowing of grassland, establishment and management of scrub and the creation of two pools. The result has been the establishment of a range of habitat types including flower-rich grassland (much of which has calcareous influences), woodland, scrub and reedbed. 18.5.3 There are no substantial water-bodies within the Development Site boundary, although two streams (Bum Brook and Holford Stream) that run west-east across the site connect to the
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 21 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology watercourses in Wick Moor, part of the Bridgwater Bay SSSI, and a minor unnamed stream discharges to the intertidal. A more substantial drain (or rhyne) forms the boundary between the site and Wick Moor (North Moor). Standing water is also limited in extent, with the largest pools being to the south of the plant sewage works and in Pixie’s Field. 18.5.4 The eastern boundary of the site is formed (moving north to south) by the operational nuclear plant, land within Bridgwater Bay SSSI and mixed farmland which has similar characteristics to that found within the site. This part of the SSSI consists of an area of flat, open improved grassland which is seasonally grazed. To the south and west of the Development Site there is further mixed farmland and a series of small villages including Wick, Shurton and Knighton. 18.5.5 The northern boundary of the Development Site lies adjacent to the Bristol Channel from which it is separated by a low cliff, between 5 and 10 metres in height. At low tide, the shore adjacent to the site comprises a relatively narrow of platform of rock, cobbles and pebbles (extending to approximately 200m from the cliff and running parallel to it), interspersed with and fringed by muddy sand. Intertidal areas to the west include more extensive areas of mobile sand, while to the east, adjacent to the built nuclear power stations, the intertidal rock platforms, mud and sand extend up to 500m from the upper shore at low water. Further east again, approximately 1km from the Development Site, the mosaic of intertidal habitats grades into an area of open mud and sand forming part of Steart Bay. ii) Designated Sites 18.5.6 Table 18.5.1 lists statutory sites which have been designated for their biodiversity conservation interest within 5km of the Development Site and non-statutory sites within 3km. Figures 18.17 and 18.18 show the location of these designated areas in relation to the HPC development boundary, with the full citations of each designated area included in Appendix 18a. Table 18.5.1: Designated Sites within 5km of the Development Site
Site Reason for Designation
International Sites:
Severn Ramsar Site This site has been designated for the following Adjacent to the SSA (taking in all intertidal and habitats and species: sub-tidal habitats) but also extending inland All SAC Features (see below); and taking in Wick and North Moor adjacent to Unusual estuarine communities associated with the SSA boundary. reduced productivity and diversity; Migratory fish (including sea trout, salmon, Allis shad and eel in addition to cited SAC species); Migratory birds in spring and autumn; Wintering waterfowl assemblage; and Internationally important wintering numbers of Bewick’s swan, white-fronted goose, shelduck, gadwall, dunlin and redshank.
European sites:
Severn Estuary Special Protection Area (SPA). This site has been designated for its wintering Adjacent to the SSA (taking in all intertidal populations of the following species: habitats) but also extending inland and taking Bewick’s swan; in Wick and North Moor adjacent to the SSA White-fronted goose; boundary
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Site Reason for Designation
Gadwall; Shelduck; Dunlin; Redshank; and The wintering waterfowl assemblage.
Severn Estuary Special Area for Conservation This site has been designated for the following (SAC) habitats and species: Adjacent to the SSA (taking in all intertidal and Estuaries; sub-tidal habitats). Intertidal Mud and Sand Flats; Reefs; Atlantic Salt Meadows; and Migratory Fish (twaite shad, sea and river lampreys).
National sites:
Bridgwater Bay SSSI. The site has been designated for the following Adjacent to the SSA (taking in all intertidal and habitats and species: sub-tidal habitats, but also extending inland Mudflats; and taking in Wick and North Moor adjacent to Saltmarsh; the SSA boundary) Shingle beach; Grazing marsh; Internationally and nationally important numbers of wintering and passage wildfowl including (in addition to species cited in other designations) black-tailed godwit, teal and grey plover (numbers of most species can be obtained from the Ramsar/SPA descriptions); A diverse invertebrate fauna of ponds and ditches; and The ecological link to the Somerset Levels and the position of the area in the context of the Severn Estuary.
Blue Anchor to Lilstock Coast SSSI Geological and geomorphological interests Adjacent to Development Site
Ge-Mare Farm Fields SSSI Species-rich flood pasture community incorporating 4.9km to South West of Development Site a lowland mire
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Table 18.5.2: Designated Sites within 5km of the Development Site
Site Reason for Designation
Local Sites: CWS Reference Number
Hinkley County Wildlife ST24/043 Species-rich scrub, coastal grassland and broad- Site. leaved woodland with ponds and areas of improved grassland Within SSA boundary.
Blue Anchor to Lilstock ST24/051 Coastal cliffs, with unimproved calcareous Coast CWS grassland and scrub habitats from Blue Anchor to Lilstock Approximately 0.6km to the west
Wick Park Covert CWS ST24/002 Ancient semi-natural broad-leaved woodland bisected by road Approximately 1.4 Km to the south-east
Monk Wood CWS ST24/001 Broad-leaved ancient woodland Approximately 1.5 Km to the south south-east
Mud House Copse CWS ST24/003 Ancient semi-natural broad-leaved woodland Approximately 1.2 Km to the south-east
Cross Elms CWS ST14/027 Small field of unimproved grassland and adjacent semi-natural broad-leaved woodland Approximately 1.8 Km to the west.
Honibere Wood CWS ST14/046 A large tract of hedged, embanked and ditched ancient semi-natural woodland occupying very Approximately 1.3 Km to wet-lying ground on coastal strip of county (north the west of Stringson).
Martin’s Wood CWS ST14/070 A more or less square tract of ancient semi- natural woodland hedge, ditched and embanked Approximately 1.4 Km to all round and with a small stream flowing the south-west eastwards along its southern edge.
Fairfield House Park CWS ST14/099 Parkland site as marked on the 1st edition Ordnance Survey map with an important Approximately 1.6 Km to assemblage of veteran trees the south-west
Cole Pool Field CWS ST14/103 Field with unimproved neutral and marshy grassland and semi-improved areas. Approximately 0.8 Km to the south south-west.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology iii) General Vegetative Characteristics 18.5.7 The majority of the land within the Development Site is in agricultural use and consists of 16 arable and 16 pasture fields. Field boundaries comprise a mixture of fence lines and mature hedgerows, some species-rich and some species-poor. Five small broad-leaved woodlands are located within the coastal fields, with other woodland being limited to Branland Copse (on the western side of the existing power stations) and a block of semi-natural plantation towards the southern boundary of the site. Discrete areas of isolated scrub are present in some of the coastal fields, with more extensive patches of dense scrub to the south of the Hinkley Point A and B. Most of the grassland within the Development Site has been agriculturally improved, but small compartments of species-rich grassland are present along the coastal strip, on the seaward side of the existing car park (and adjacent training buildings) and to the south of the operational plant. Waterbodies are limited to a heavily scrub-encroached pool towards the north-western edge of the site boundary and further pools at Pixie’s Mound and at the sewage works. In addition, there are a number of seasonal ditches and two more permanent water features (Holford Stream and Bum Brook) that flow west to east and are hydrologically linked to land within Bridgwater Bay SSSI to the east. These water features show signs of agricultural improvement, and lack diverse and consistent riparian vegetation or aquatic communities (see Section 18.5.40, below). The exception is the main drain separating the Development Site boundary from the SSSI, which supports considerable aquatic vegetation, and links to the Sewage Works area, where a discrete area of reedbed is present. 18.5.8 The results of the Extended Phase 1 Habitat Survey are shown on Figure 18.3. A detailed Phase 1 Habitat Survey report, incorporating the Hedgerow Assessment and Woodland Condition Survey is found in the Habitat Report in Appendix 18b. A separate NVC report is found in Appendix 18c. iv) Detailed Description of Vegetation 18.5.9 The following sections summarise the results of the NVC, the Woodland Condition Survey, the Hedgerow Survey and the River Corridor Survey. b) Grassland 18.5.10 Most of the grassland within the Development Site is improved and species-poor pasture dominated by perennial rye grass (Lolium perenne) with white clover (Trifolium repens). In some of the fields within the Built Development Area West the sward is more structurally diverse and supports a greater range of species. This increased structural diversity has been the gradual result of management by British Energy, which has included mowing rather than grazing of these coastal fields in recent years. 18.5.11 A further area of coastal grassland outside the CWS is being managed, through a Countryside Stewardship agreement, to gradually create a neutral to calcareous grassland community. This field, which was formerly under arable, at present (taking into account the species present and its management history) conforms most closely to improved grassland (JNCC, 2003) (Ref. 18.1), and has been mapped as such. Nevertheless, there are local indications that calcareous species, and species of disturbed ground are moving into the sward. 18.5.12 The coastal strip, the area of semi-improved grassland to the north of the existing car park/training buildings, Pixie’s Mound Field two habitat compartments to the south of the built plant and two of the fields within the Southern Construction Phase Area were subject to detailed survey using the NVC. These areas are shown on Figure 18.1. 18.5.13 Grassland within the CWS exhibits a range of characteristics, and these have been summarised below (a full account can be found in Appendix 18c).
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 25 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.14 The stand of grassland along and adjacent to the coastal footpath between the fence and the soft cliff edge is generally only a few metres wide and has been narrowed in places by scrub invasion. Management consists of occasional scrub clearance and infrequent mowing, but otherwise the vegetation is maintained through trampling by walkers with some rabbit grazing. The sward is species-rich and dominated by an evenly balanced mixture of broad-leaved herbs and fine-leaved grasses. Red fescue (Festuca rubra) and smaller cat’s tail (Phleum bertolonii) are the most abundant grasses, with the herbs agrimony (Agrimonia eupatoria), bird’s-foot trefoil (Lotus corniculatus), bulbous buttercup (Ranunculus bulbosus), glaucous sedge (Carex flacca), ribwort plantain (Plantago lanceolata) and hairy violet (Viola hirta) being particularly distinctive. The sward is variable in height but mostly around 15-20cm and rather dense. The sward is especially distinctive for its frequent occurrence of indicators of calcareous conditions. Adder’s tongue (Ophioglossum vulgatum), characteristic of old pastures and rather uncommon, is also present in a single colony. 18.5.15 Within the CWS, but outside of the sampled quadrats, bee orchid (Ophrys apifera) and carline thistle (Carlina vulgaris) (both of which are listed within the Somerset Notable Species Dictionary as uncommon) together with common restharrow (Ononis repens) were recorded. Greater butterfly orchid (Platanthera chlorantha) and wild thyme (Thymus polytrichus) which are also listed as uncommon have been recorded in recent years (ADAS, 2006, 2005). 18.5.16 The sward in Pixie’s Mound Field is characterised by sub-communities and variants of MG6 (perennial rye grass-crested dog’s tail grassland), the distribution of which is probably determined by the position of rabbit warrens (and resulting grazing and digging). Approximately half of the field is occupied by perennial rye grass-crested dog’s tail (Lolium perenne-Cynosurus cristatus) grassland typified by a species-poor sward in which competitive or coarse grasses such as perennial rye grass, creeping bent (Agrostis stolonifera) and cock’s foot (Dactylis glomerata) dominate. 18.5.17 Much of the remainder of the Pixie’s Mound field has been classified as MG6c (perennial rye grass-crested dog’s tail grassland with a yellow oat-grass sub community), with three variants present. This variation partly reflects different levels of rabbit grazing and that the sward is recovering more quickly in some places than others (it is in a process of gradual reversion from improved pasture). Species indicative of older, more established grasslands, such as bird’s- foot trefoil and fairy flax (Linum catharticum) are also present. 18.5.18 The field on the western side of Wick Moor Drove, and a very small compartment of the Pixie’s Mound field correspond most readily to an MG1(a) false oat grass (Arrhenatherum elatius) grassland, red fescue sub-community, a ubiquitous grassland type in the lowlands of southern England, usually in situations of low management intensity. One county notable species, grass vetchling (Lathyrus nissolia), was recorded; 18.5.19 The area of grassland between the existing training buildings/car park and the coastal strip was considered intermediate between MG5 crested dog’s tail-black knapweed (Cynosurus cristatus- Centaurea nigra) grassland and MG1(e) false oat grass grassland, centaurea nigra sub- community. To the north the stand terminates in a large patch of nettle and elder scrub, and to the south it grades into an area of mown amenity grass fronting the Training Centre. Grasses dominate the relatively short (15-20cm) species-rich sward. Creeping bent, cock’sfoot, red fescue, crested dog’s tail and common bent (Agrostis capillaris) are the main component species, although false oat grass is prominent in places. Meadow herbs are prominent, and especially distinctive are those indicating calcareous soils – agrimony, glaucous sedge, oxeye daisy (Leucanthemum vulgare), pyramidal orchid (Anacamptis pyramidalis), and less commonly, yellow-wort (Blackstonia perfoliata) and burnet-saxifrage (Pimpinella saxifraga). Mosses are abundant, especially where total vascular plant cover is lower.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.20 The thin strips of open ground maintained between dense scrub to the south of the existing power station comprise three grassland communities. The first is an indeterminate NVC community between MG5b crested dog’s tail – black knapweed grassland, lady’s bed straw (Galium verum) sub-community and CG6 downy oat grass (Helictotrichon [Avenula] pubescens) grassland. Fine-leaved grasses such as creeping bent and red fescue and the unpalatable teasel, ground-ivy and creeping cinquefoil (Potentilla reptans) are constant within the sward (these latter indicating that rabbit grazing is especially intense), as are species such as agrimony, bird’s-foot trefoil, oxeye daisy and white clover. The community is distinctive for the frequency of species indicative of calcareous conditions, such as glaucous sedge, dogwood (Cornus sanguinea), the eyebright Euphrasia nemorosa, smooth hawk’s beard (Crepis capillaris), flattened meadow grass (Poa compressa), common centaury (Centaurium erythraea), hairy violet and pyramidal orchid. The sward is generally very short (5-10cm) with very little plant litter recorded (approximately 15% cover). As a consequence of these conditions, this community is very species-rich (averaging 41 species per quadrat). 18.5.21 A second community recorded in the area described above, considered to be indeterminate between MG5 crested dog’s tail – black knapweed grassland, CG7 sheep’s fescue-mouse-ear hawkweed-wild thyme-large thyme grassland and SD8 red fescue-lady’s bedstraw fixed dune grassland was present on a small strip of very parched ground which runs along the fenced southern boundary of the current power station. Due to the free-draining nature of the soil and disturbance from rabbits, this community has a high species-richness (averaging 39 species per quadrat). 18.5.22 A third community present in this area is considered indeterminate between MG5 crested dog’s tail grassland and CG6 downy oat grass grassland. The sward is generally only 5-20cm tall but is overtopped by a continuous layer of teasel. Patches of bare ground are frequent (approximately 10-15% over) and leaf litter is generally low due to rabbit grazing. Beneath the teasel, mixtures of fine-leaved grasses (such as red fescue and creeping bent) are accompanied by a wide range of herbs. Many of the herbs are low growing species, such as selfheal, bird’s- foot trefoil, wall speedwell, lesser trefoil, fairy flax and smooth hawksbeard. Others constitute unpalatable species, such as ground-ivy, bristly oxtongue (Picris echioides), creeping thistle (Cirsium arvense) and bramble (Rubus fruticosus). 18.5.23 The final communities within the CWS are those associated with the Sewage Treatment Works. The first of these is the MG5a crested dog’s tail – black knapweed grassland, meadow vetchling (Lathyrus pratensis) sub-community which occurs on the embankments surrounding the sewage treatment works (on the western and southern sides). It is a distinctly colourful community, dominated by herbs of moderate height such as black knapweed, yellow-rattle (Rhinanthus minor), bird’s foot trefoil, oxeye daisy, meadow buttercup (Ranunculus acris), pyramidal orchid and wild-carrot (Daucus carota). Grasses such as yorkshire fog, red fescue and smooth meadow grass are constant in the sward but are not dominant. The vegetation also contains moderate quantities of legumes such as black medick (Medicago lupulina), white clover and red clover (Trifolium pratense). There is modest bryophyte cover (averaging 10%) which consists largely of Calliergonella cuspidate. Overall the community here is of moderate species-richness (averaging 27 species per quadrat), with species characteristic of a lack of agricultural improvement. 18.5.24 A second community, considered indeterminate between MG5 crested dog’s tail – black knapweed grassland and SD8e red fescue-lady’s bedstraw fixed dune grassland, selfheal sub- community was recorded from a small, heavily rabbit grazed area to the west of the sewage treatment works. Consequently the sward is noticeably shorter than the surrounding vegetation (only 2-3cm in height), with bare ground representing 15-20% cover and only small amounts of leaf litter. The vegetation lacks a single dominant species, but instead has a diverse mixture of
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 27 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology fine-leaved grasses (such as red fescue, sheep’s fescue, smooth meadow grass, creeping bent and yellow oat-grass), rosette species (such as daisy (Bellis perennis), dandelion (Taraxacum officinale), oxeye daisy and selfheal) and diminutive herbs (such as fairy flax and scarlet pimpernel). Notable species (at a county level) are pyramidal orchid, yellow-rattle and upright brome (all uncommon in Somerset); 18.5.25 The third community recorded in the area around the Sewage Treatment Works was classified as an MG1a false oat grass grassland, red fescue sub-community. False oat grass was the dominant species, usually with associates of creeping thistle, yorkshire fog, smooth meadow grass, cut-leaved cranesbill (Geranium dissectum) and field bindweed (Convolvulus arvensis). The community was found to contain very occasional county notable species including yellow rattle, grass vetchling and adder’s tongue fern, but is relatively ubiquitous in the British lowlands. 18.5.26 Outside the CWS, the botanical interest of the grassland habitats was more limited. 18.5.27 The more southerly of the two fields has an element of MG1a arrhenatherum elatius grassland, Festuca rubra sub-community as described above. The field is currently a young plantation, and the central part and the various tracks that radiate from it have a community that is classified as conforming to MG6a perennial rye grass-crested dog’s tail grassland. The sward is dominated by Yorkshire fog, with constant associates of perennial rye grass and smooth meadow grass. These grasses are accompanied by a range of legumes (particularly white clover and lesser trefoil, but also common vetch (Vicia sativa), grass vetchling, hop trefoil (Trifolium campestre) and smooth tare (Vicia tetrasperma)) as well as small monocots (such as carnation sedge (Carex panicea), crested dog’s tail and creeping bent). The predominant community is widespread and abundant, being typical of permanent pasture on moist, circum-neutral soils with a mesotrophic status (Rodwell, 1992). 18.5.28 The other community noted in this southerly field was indeterminate but bore most affinity to MG1 false oat grass grassland. The area is uncut (parts of the rest of the field are mown) vegetation dominated by sedges and grasses of moderate stature (including carnation sedge, false oat grass, yorkshire fog, common couch (Elytrigia repens) and glaucous sedge). The sward has a rank appearance as a result of the frequent occurrence of creeping thistle, white bindweed and bramble. However it also contains a number of colourful herbs such as square- stalked St John’s wort (Hypericum tetrapterum), common fleabane (Pulicaria dysenterica), field forget-me-not (Myosotis arvensis) and white clover. The community indicates both calcareous influences and (possibly) impeded drainage. The sward is not generally species-rich but does contain the county notable pyramidal orchid. 18.5.29 The other field surveyed within the Southern Construction Phase Area is bisected by Holford Stream. The community here was classified as MG10a yorkshire fog-soft rush (Holcus lanatus- Juncus effusus) rush-pasture with a typical sub-community. The vegetation is dominated by yorkshire fog, with abundant smooth meadow grass, creeping bent, broad-leaved dock (Rumex obtusifolius) and perennial rye grass. Other species recorded in the sward tended to be coarse grass species (such as false oat grass and cock’sfoot) or herbs ubiquitous in mesotrophic grassland (such as creeping buttercup, white clover and creeping thistle). Occasional species recorded within the northern part of the field (such as marsh foxtail (Alopecurus geniculatus), hard rush (Juncus inflexus), cuckoo flower (Cardamine pratensis) and compact rush (Juncus conglomeratus)) suggest slightly moister soils than the southern field. However both fields lacked a bryophyte layer and were generally very species-poor. The only notable species recorded was grass vetchling, which showed a very scattered distribution.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology c) Woodland and Scrub 18.5.30 There are 9 areas of mature woodland within the SSA boundary. These are shown on Figure 18.19. The area of young plantation woodland in the southern part of the site was excluded from the survey due to its very recent origin (although the grassland within it was subject to sampling during the NVC survey). Figure 18.19 also references the local names of the woodland compartments. A summary of the characteristics of the individual woodlands is contained in Table 18.5.3:
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Table 18.5.3: Summary of Woodland Condition Features
Woodland Grid Size Current Structure Woodland Other Habitat Adjacent Species Present Current and Past Historical Reference (ha) Vegetation Types Land Use Management Presence Types
A ST199458 0.3 Established Closest affinity None Arable and Common Evidence of Broad-leaved trees woodland to NVC poor-semi- woodland coppicing and present from 1904 dominated by ash. community W8 improved species only. hedge laying. No (conifer in 1887) Sparse understory Fraxinus grassland apparent recent and underground excelsior-Acer management flora. campestre – Mercurialis perennis.
B ST200456 0.9 English elm English elm Ditch present Arable and Common Evidence of Scrub woodland in comprises canopy dominated along poor-semi- woodland felling of elms 1897, marked as with limited under northern improved species only. and former broad-leaved storey. Edges boundary grassland hedge laying woodland in 1904 more diverse around edges
C ST203457 0.9 Established Closest affinity None Arable and Common Edge remnant No woodland woodland, to NVC poor-semi- woodland hedges shown in 1887 (2 remnant hedges at community W21 improved species only. previously laid, linear fields only), the edge and Crataegus grassland centre area broad-leaved in scrub under storey monogyna – managed by 1904 in centre Hedera helix selective felling, scrub. clearance and re- planting to promote diversity.
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Woodland Grid Size Current Structure Woodland Other Habitat Adjacent Species Present Current and Past Historical Reference (ha) Vegetation Types Land Use Management Presence Types
D ST202460 0.9 Open woodland in Closest affinity Watercourse Arable and Common Evidence of Broad-leaved western part, to NVC through poor-semi- woodland historical /scrub woodland denser to east with community W8 centre of improved species only. coppicing, recent present on east mature oak and Fraxinus woodland grassland management side of stream in field maple excelsior-Acer through selective 1887 and 1904. campestre – felling, clearance Woodland not Mercurialis and re-planting present on west perennis. to increase side until more diversity. recently
E ST200457 0.1 Although small the Closest affinity Ditch through Arable and Common Evidence of No woodland structure is well to NVC centre of poor-semi- woodland previous hazel shown in 1887, developed. community W8 woodland improved species only. coppicing. broad-leaved in Ground flora Fraxinus grassland 1904 species-poor excelsior-Acer campestre – Mercurialis perennis.
F ST197456 0.1 Many of the elm English elm Damp ditch Arable and Common No evidence of Shown as broad- are either dying or dominated around poor-semi- woodland management leaved woodland are young and southern improved species only. throughout, size thin. Limited edge of wood grassland contracts between structure and 1887 and 1904 species-poor ground flora
G ST205451 0.4 Few mature trees Closest affinity None Arable and Common No evidence of Conifer and scrub within canopy, to NVC poor-semi- woodland past indicated in 1887 dense under community W8 improved species only. management, in the north part of storey layer Fraxinus grassland currently the wood. Mixed
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Woodland Grid Size Current Structure Woodland Other Habitat Adjacent Species Present Current and Past Historical Reference (ha) Vegetation Types Land Use Management Presence Types
excelsior-Acer managed by woodland shown campestre – selective in 1904. Mercurialis clearance and re- perennis. planting to increase diversity.
H ST207458 2.8 Predominantly Closest affinity Glades have Buildings and Common No evidence of Present as broad- mature standard to NVC been created hard- woodland past leaved woodland trees with open community W8 standing, species only. management, in 1887 and 1904, under storey. Fraxinus scrub and currently size increases to excelsior-Acer calcareous managed by the north between campestre – grassland selective years Mercurialis mosaics. clearance and re- perennis. planting to increase diversity.
I ST207459 1 Few standard trees Closest affinity None Buildings and Common No evidence of No woodland in canopy, with a to NVC hard- woodland past present in 1887. dense under community W8 standing, species only. management, Broad-leaved storey and patches Fraxinus scrub and currently woodland in 1904 of more diverse excelsior-Acer calcareous managed by ground flora campestre – grassland selective Mercurialis mosaics. clearance and re- perennis. planting to increase diversity.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.31 All of the semi-natural broad-leaved woodlands with the Development Site are small, ranging between 0.1ha to 2.8ha. They are well connected to each other by the network of hedgerows, but none are adjacent to extensive areas of semi-natural habitat. 18.5.32 Although the structure and characteristic dominant species in each woodland vary slightly, all the woodlands apart from Woodlands C and F, correspond broadly to NVC community W8 ash- field maple-dog’s mercury (Fraxinus excelsior-Acer campestre-Mercurialis perennis). This is due to the dominance or presence of ash and field maple in each of the woods, despite the absence of dog’s mercury. Based on the species-poor ground flora in woodlands A, D, E, G, H and I, the ivy sub-community shows most affinity with these woodlands. Woodland B supports few ash or field maple trees as it is dominated by English elm (Ulmus procera). Due to this dominance of elm, Woodland B corresponds closer to the herb-robert (Geranium robertianum) sub- community, in which elm frequently occurs in varying abundance. 18.5.33 Woodlands C and F support little ash and field maple, whilst scrub species such as hawthorn (Crataegus monogyna) and blackthorn (Prunus spinosa) are dominant. Therefore, these woodlands correspond better with NVC community W21 hawthorn-ivy (Crataegus monogyna – Hedera helix) scrub. Again, due to the dominance of ivy in the ground flora the ivy-common nettle (Hedera helix – Urtica dioica) sub-community fits best with the species present in both woodlands. 18.5.34 Both these NVC woodland communities occur commonly throughout the UK and can be species- rich and structurally diverse. Within the Development Site, however, correspondence to the ivy sub-communities of both W8 and W10 demonstrates that the woodlands are species poor. The ivy sub-community of W8 is often species-poor to the extent that dog’s mercury is confined to the edges of the woodland, or if absent altogether (which is the case within the site) it can demonstrate the recent evolution of the woodland. The ivy-common nettle sub-community of W21 is also predominantly species-poor reflecting the dense canopy. 18.5.35 None of the woodlands within the Development Site are considered to be ancient (i.e. they were not present prior to 1600AD) and many have only developed over the last 100 years. The recent development of the woodlands is likely to contribute significantly to their species-poor and structurally similar character. 18.5.36 Notwithstanding this, it appears from recent management activities completed in Woodlands C, D, G, H and I that these woodlands have the potential to support a greater diversity of species with suitable management intervention. Additionally, whilst the woodlands are species-poor and do not support rare plant species, they do provide habitat for a range of fauna, including notable bird species such as nightingale and legally protected species such as badger. i) Hedgerows 18.5.37 The network of mature hedgerows within the Development Site provides cover, seasonal and permanent foraging and dispersal opportunities for a range of species groups. Of particular note in this respect is the track on the western boundary (Benhole Lane) and the track that cuts through the site in an east-west direction (the Green Lane), as these have mature intact hedgerows alongside them. The hedgerow network also provides links between woodland pockets on and off site. 18.5.38 Of the 60 hedgerows within or directly adjacent to the site, the survey undertaken concluded that 38 are ‘important’ under the Hedgerow Regulations (1997). Eighteen of these hedgerows were considered important as they supported seven or more woody species within the 30m survey area(s) (although 29 of the hedgerows supported seven or more woody species within their entire length). The maximum number of woody species recorded growing in a hedgerow was 12 (Hedgerow 42), with five other hedgerows supporting 10 or 11 species.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 33 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.39 Although footpaths are located adjacent to a number of hedgerows, only three hedgerows (Hedgerows 2, 23 and 34) are ‘important’ solely due to this (i.e. they would not be ‘important’ due to the limited species present without the footpath). ii) Watercourses 18.5.40 The network of watercourses (see Figure 18.11) is less notable than the hedgerows. There are a limited number of watercourses within the Development Site boundary, and those that are present are poorly connected, seasonal or ephemeral, are encroached in places by ruderal vegetation and show signs of agricultural improvement. Bum Brook, which runs along the southern boundary of the Development Site, and the considerable ditch separating the site from Wick Moor are the most important wetland features within or adjacent to the Development Site, as they are permanent features and are linked to the Bridgwater Bay SSSI. 18.5.41 The minor watercourse (Watercourse 1) that issues at ST197456 and flows east, then north through Whitewall Brake before discharging to the foreshore at ST202461 is approximately 1km in length and varies in width between 0.5m and 1m. It has a steady flow of water estimated at ~20-30cm deep during the wetter, winter months, but the section upstream of Whitewall Brake is dry for much of the year. The watercourse passes through three culverts and has earth banks (some of which have been re-profiled) along its entire course. Approximately 70% of the stream bed has a muddy substrate, although in Whitewall Brake gravel predominates. The north- eastern section of the watercourse has sparse bank-side and channel vegetation limited to fool’s water-cress (Apium nodiflorum), hemlock water-dropwort (Oenanthe crocata) and bramble. Within Whitewall Brake the banks support a range of ruderal and marginal species, which quickly shade the water in the summer. Species present include bramble, creeping thistle, great willowherb (Epilobium hirsutum), common nettle, hemlock (Conium maculatum), hemp-agrimony (Eupatorium cannabinum), water figwort (Scrophularia auriculata) and fool’s water-cress. The mature trees within Whitewall Brake, including crack willow (Salix fragilis) and hawthorn shade this section of the watercourse throughout the year. 18.5.42 A second minor watercourse (Holford Stream/Watercourse 4) flows west to east across the centre of the Development Site before joining with the complex of drains that cross Wick Moor beneath the Power Station approach road. The watercourse is between 0.5 and 1m wide and varies in depth between 0.1 and 1m. Holford Stream passes through five culverts and under one stone bridge. The western section of the watercourse is ephemeral, and supports well established grassland and ruderal vegetation. The central section, which dries out during summer, is extensively poached, with a silt and mud base and has low water clarity. Freshwater plants in the channel are limited to fool’s-watercress and brooklime (Veronica beccabunga). The eastern part of the watercourse is less cattle poached and has been recently dredged. 18.5.43 The bank opposite the hedgerow on the eastern section of the Holford Stream is generally species-rich, supporting a range of ruderals and grasses including meadowsweet (Filipendula ulmaria), hard rush, reed sweet-grass (Glyceria maxima), false oat-grass and hemlock water- dropwort. Within the channel, common reed (Phragmites australis) is locally dominant (up to 20% cover) and duckweed (Lemna minor) covers up to 95% of the water surface. Water- crowfoot (Ranunculus aquatilis) also occurs in dense sub-merged patches where the water is deeper. Water forget-me-not (Myosotis scorpioides), brooklime and creeping buttercup also occur within the channel. 18.5.44 Watercourse 3 (see Figure 18.11) demarcates the boundary between North Moor and the Development Site (running north-east from Wick Moor Drove) is approximately 1m wide and has steep earth banks up to 70cm in height. The bed of the watercourse is predominantly muddy, with vegetated mud platforms at the base of the banks. The watercourse has a steady flow of water: an estimated 70cm of water was present during March 2007, but the western section dries up during the summer. The east section, around the Sewage Treatment Works retains
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology water throughout the year. The banks are approximately 40-50cm tall on the northern side and 30cm tall on the southern side with some sections being heavily poached by cattle from the adjacent fields. 18.5.45 The far eastern end of Watercourse 3 had the greatest diversity of macrophytes recorded during the survey, with lesser pondweed accompanied by curled pondweed (Potamogeton crispus) and canadian pondweed (Elodea canadensis), overtopped by a layer of common duckweed (Lemna minor) and occasionally ivy-leaved duckweed (Lemna trisulca). Emergent vegetation consisted solely of common reed (Phragmites australis), which in places was encroaching into the centre of the ditch. Further west along the ditch, bulbous rush (Juncus bulbosus) replaces the native pondweeds (Potamogeton) species and elodea declines in abundance. Emergent vegetation shows a greater number of marshy species such as water plantain (Alisma plantago-aquatica), creeping-jenny (Lysimachia nummularia) and water forget-me-not (Myosotis scorpioides), amongst the persistent Phragmites cover. Along the western-most stretch of the ditch, water depth declines rapidly until the ditch bed becomes dry and emergent vegetation dominates, including hemlock water-dropwort, great willowherb, common reed and reed canary-grass (Phalaris arundinacea). 18.5.46 The final watercourse (5) within or adjacent to the Development Site comprises Bum Brook and Bayley’s Brook (which join adjacent to the site and then separate near to Stolford into the West Brook and East Brook). The watercourse varies in width and depth, but along most of its length adjacent to the site it is approximately 1m wide and 30-50cm deep with a fairly fast flow. Water clarity improves in the eastern section. The watercourse flows east from Benhole Lane, and forms a field boundary between arable and pasture fields. It is very shaded along its eastern section due to extensive bank vegetation, which includes bramble, nettle, Himalayan balsam (Impatiens glandulifera) and great willowherb with overhanging semi-mature crack-willow trees. The banks comprise earth in this location and are ~70cm tall. 18.5.47 Further downstream the earth and stone banks are taller and unshaded. The base substrate is a mixture of silt and pebbles. Species recorded on the banks include cow parsley (Anthriscus sylvestris) and hemlock water-dropwort, with branched bur-reed (Sparganium erectum) and fools water-cress within the channel. Further downstream, a hedgerow is present on the southern side of the watercourse which again shades the channel. iii) Standing Water-bodies 18.5.48 There are three water-bodies within the SSA (refer to Figure 18.1)including:
Pixie’s Pond (located at ST209 455) is approximately 12m long by 8m wide. In 2007 common reed covered an estimated 75% of the water surface with an area of open water in the centre, but clearance in 2008 reduced the common reed cover to 40%. The banks are reinforced using wooden stakes on the northern side and are shallow (~10cm) around the rest of the perimeter. Bulrush (Typha latifolia), meadowsweet, marsh-marigold (Caltha palustris) and water mint (Mentha aquatica) occur around the edges of the pond; The second water body located at ST216 457 is a large pond (~15m x 15m) that is approximately 60% vegetated by common reed with only 40% of the pond surface being open water. Plant species diversity is limited due to the dominance of common reed with small amounts of bittersweet (Solanum dulcamara) and great willowherb present. The water body is in excess of 1m deep and the water clarity is poor. The pond has very shallow margins around the edges without proper banks. The northern and western edges of the water body have overhanging crack willow trees creating some shading; and The final pond is located within a hedgerow boundary adjacent to an arable field to the north west of Built Development Area West. The pond has a mixture of willow and hawthorn growing in the centre and is prone to drying out regularly (e.g. in July 2009), although can be over 20m long by 8m wide. There are very few aquatic or marginal broad-leaved plants and
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 35 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology although there are areas of open water, the pond is 90% shaded by surrounding scrub and hedgerows. d) Birds 18.5.49 The desk study resulted in considerable information being collated with regard to breeding, wintering and intertidal birds. A summary report on the ornithological interest of the area, is presented in Appendix 18d. Drawing upon this material, the following sections describe the findings of the desk study and the results of field surveys for the Development Site. i) Breeding Birds - Desk Study Information 18.5.50 British Energy Conservation Wardens have undertaken breeding bird surveys of scrub and woodland habitats to the south and west of the existing nuclear power stations at Hinkley on an annual basis since 2000 (see Figure 18.20). The results of these are included in the annual land management reviews (British Energy/ADAS 1999-2007) (Ref. 18.32). Prior to the initiation of annual surveys, ornithological survey work was conducted sporadically. 18.5.51 The features of breeding in the bird community that are of greatest interest are lesser whitethroat, which is close to the western limit of its breeding range in Somerset (Ballance, 2006) (Ref. 18.4), and nightingale, which has a restricted national distribution. Nightingale numbers fluctuate, with a maximum of six territories in 1998 (two in 2008, up to five in 2007 and 2005, four in 2004 and three in 2003, 2002 and 2000). One pair of lesser whitethroats (occasionally two pairs) consistently breeds in scrub within the annually monitored area and black redstart, which is protected under Schedule 1 of the Wildlife and Countryside Act (1981) (As amended), bred within the grounds of the power station in 1996. Peregrine are frequently seen around the built plant, although are not known to breed. 18.5.52 This annual monitoring work undertaken by the site warden built on baseline surveys of the same woodland and scrub habitats undertaken by Somerset Ecology Consultants (SEC) in 1992 and 1993 (SEC, 1993). These surveys were also undertaken to CBC methodology, and (in 1992) ran in conjunction with a ringing programme. Six nightingale territories were recorded in 2002 and three in 2003. Two lesser whitethroat territories were recorded in 2002. Willow and marsh tit, which are red listed species of conservation concern (Gregory et al., 2002), were recorded as breeding species during the work. Willow tit is on the verge of extinction at county level, while marsh tit is uncommon (Ballance, 2006) (Ref. 18.4). Neither species appears to have been recorded breeding in the area since this time. 18.5.53 An earlier CBC survey conducted by Robins (1986) in relation to the former Hinkley C proposal took in the coastal fields (where the new plant will be located) plus an area extending approximately 500m to the west and south and 1km to the east. Features of the bird community at that time were nightingale, with six territories located (five in woodland and one in scrub) and lesser whitethroat, with nine territories (eight of which were in hedgerow and one in scrub). Farmland birds included 1 pair of corn bunting, which is now considered extinct as a breeding species in Somerset (Ballance, 2006) (Ref. 18.4), and a number of red-listed species of conservation concern, including grasshopper warbler (1), bullfinch (2), spotted flycatcher (3), song thrush (4), grey partridge (5), yellowhammer (7) and starling (10). Skylark was present at low density in the agricultural fields (12 pairs at an overall density of 5.8 km2). 18.5.54 The West Hinkley Wind Farm application, considered an area of land partially to the west of the proposed HPC build area, although there is a considerable degree of overlap between the two development proposals. Two breeding bird surveys were undertaken in relation to the wind farm application, the first by Ecology Consulting in 2003 and the second by Terence O’ Rourke Ltd in 2006.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.55 The Ecology Consulting surveys covered the Wind Farm plus a perimeter area of 300m around it (see Figure 18.20). Species considered to be breeding within the survey area included shelduck (2), buzzard (1), skylark (16), lesser whitethroat (3), linnet (6) and yellowhammer (1). Nightingale was not recorded within the survey area, although three pairs are known at this time to have held territory in scrub in close proximity to the power station from the annual BE work. 18.5.56 Terence O’ Rourke undertook a ten visit CBC between March and July 2006. This survey work included eight morning and two afternoon visits and covered the Wind Farm application area only (1.3km2). Nightingale and lesser whitethroat were not recorded holding territory in the survey area (which did not take in the favoured scrub and woodland habitats adjacent to the built plant), but species that were present included skylark (30), song thrush (2), linnet (5) and yellowhammer (1). The relatively high density of skylark recorded in comparison to the Ecology Consulting surveys (which covered a larger area) may have been due to natural fluctuation in numbers or possibly changes in management of the arable fields, although no evidence for this is presented in the report. 18.5.57 The agricultural buildings within the Development Site have been subject to a number of previous surveys. Robins (1986) reported that barn owl was regularly recorded hunting over the survey area and had formerly nested in the extant barn at ST208 456. The other surveys (Ecology Consulting and Terence O’Rourke 2006) concluded that breeding barn owl were not present, but that one of the buildings was used as an occasional roost. e) Breeding Birds - Survey Data 18.5.58 The survey programme resulted in 45 species of breeding bird being recorded across an area approximately 4.6km2 in extent. The recorded species are listed in Table 18.5.4. The location of breeding territories is shown on Figures 18.18 and 18.21 to 18.26. A key indicating the species that each code refers to is also provided. It should be noted when considering the figures that the two letter registrations refer to the apparent centre of territorial activity rather than nest sites. 18.5.59 The aim of this survey was to characterise the bird community rather than derive exact densities, which would require a considerably more involved survey programme. As such the densities of some mobile, vocal species may have been overestimated due to the precautionary approach that has been taken in interpreting the data, where peak counts of apparently territorial birds have been used to derive densities. Where potential overestimation is considered likely this is acknowledged in the following text. Table 18.5.4: Numbers of Breeding Bird Territories Recorded in the Survey Area
Species BTO 2- Number of Wildlife and Species of Birds of Birds of letter Code Territories Countryside Principal Conservation Conservation used on recorded in Act Schedule Importance Concern Red Concern Figure Survey Area 1/Annex 1 of (NERC Act, List Amber List 18.22 EU birds 2006) Directive
Buzzard BZ 1
Pheasant PH 15
Moorhen MH 3
Oystercatcher OC 1 Y
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Species BTO 2- Number of Wildlife and Species of Birds of Birds of letter Code Territories Countryside Principal Conservation Conservation used on recorded in Act Schedule Importance Concern Red Concern Figure Survey Area 1/Annex 1 of (NERC Act, List Amber List 18.22 EU birds 2006) Directive
Woodpigeon WP 23
Stock dove SD 3 Y
Cuckoo CK 3 Y Y
Green G 2 Y woodpecker
Great spotted GS 2 woodpecker
Skylark S 58 Y Y
Meadow pipit MP 1 Y
Rock pipit RC 2
Pied wagtail PW 1
Wren WR 97
Dunnock D 56 Y Y
Robin R 60
Nightingale N 5-6 Y
Blackbird B 41
Song thrush ST 16 Y Y
Cetti’s warbler CW 3 Y
Sedge warbler SW 5
Reed warbler RW 34
Garden warbler GW 1
Lesser LW 7 whitethroat
Whitethroat WH 70 Y
Blackcap BC 36
Willow warbler WW 13 Y
Chiffchaff CC 42
Goldcrest GC 4 Y
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Species BTO 2- Number of Wildlife and Species of Birds of Birds of letter Code Territories Countryside Principal Conservation Conservation used on recorded in Act Schedule Importance Concern Red Concern Figure Survey Area 1/Annex 1 of (NERC Act, List Amber List 18.22 EU birds 2006) Directive
Blue tit BT 29
Great tit GT 21
Long-tailed tit LT 2
Starling SG 2 Y Y
Magpie MG 4
Jackdaw JD 1
Carrion crow C 2
Rook RO 122
House sparrow HS 3 Y Y
Chaffinch CH 65
Greenfinch GR 28
Goldfinch GO 22
Bullfinch BF 3 Y Y
Linnet LI 20 Y Y
Yellowhammer Y 27 Y Y
Reed bunting RB 13 Y Y
* Cuckoo numbers are difficult to accurately census as they are highly mobile, vocal and/or have complex breeding ecology. Therefore, it is probable that the number of pairs of cuckoo have been overestimated.
18.5.60 The breeding bird survey found that the most common species in the survey area were a mixture of farmland birds and ubiquitous species with wide ranging habitat preferences. The large rookery in Branland Copse (109 nests) and a smaller rookery of 12 nests at Wick resulted in rook being the most abundant breeding species recorded. Other common species included wren, whitethroat, chaffinch, robin and dunnock which bred in the woodland, scrub and hedgerow habitats throughout the survey area. The most common species (other than rook) with a strong association with open farmland were skylark and yellowhammer. 18.5.61 Skylark was generally sparsely distributed in the survey area, with a notable aggregation of registrations in arable fields in the eastern part of the survey area. Yellowhammers were mainly found in farmland in the southern and south-western parts of the survey area. Concentrations of breeding records occurred along Wick Moor Drove and along a footpath just to the north of Bullen Farm. The mature and extensive hedgerows and scrub that occur in these locations, combined with the proximity of arable farmland for foraging provide suitable local breeding conditions for the species.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 39 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.62 The density of breeding birds was greatest in the mosaic of scrub and wetland habitats to the south of the built nuclear power stations. Notable species breeding in this area included up to four pairs of lesser whitethroat (two pairs were recorded during the surveys and a potential additional two pairs were recorded by ADAS, with a total of seven pairs across the entire survey area), two pairs of nightingale (combined ADAS and EIA survey data), and three pairs of Cetti’s warbler as well as red-listed passerines such as linnet. Nightingale numbers may have been underestimated during the survey work, as the May territory mapping survey missed the peak song period due to bad weather. In general four-five pairs are present in the scrub and woodland to the south of the built plant. Information from ADAS has been used to populate the results given in Table 18.5.4. 18.5.63 Reed warbler occurred in wetland habitats (ditches and reedbed) in the eastern half of the survey area, with the highest density of registrations being around the Sewage Works. Other species with a wetland association such as sedge warbler and reed bunting were also present, but occurred in lower numbers. Grasshopper warbler, which was recorded ‘reeling’ from ditch- side vegetation on Wick Moor, is likely to have been a passage migrant. 18.5.64 Conditions within the survey area have remained consistent since the generic breeding bird survey was undertaken in 2007. It is therefore reasonable to assume that the species composition remains consistent and that numbers of individual species are subject to minor inter annual fluctuations (as is shown by data sets collected by BE since 2000). Since the formal breeding bird survey work was conducted, raven is known to have begun to breed on gantries associated with overhead lines on Wick Moor. 18.5.65 The survey work conducted in 2009 and all previous internal barn inspections and desk study information suggest that barn owl occurs irregularly within the Development Site, with most sightings during the pre- or post-breeding dispersal periods (e.g. on 17 March and 21 August 2008) or during winter. There is no indication, from survey work or other available information, that barn owl have ever breed in trees within the Development Site. i) Intertidal Birds - Desk Study Information 18.5.66 Baseline intertidal survey data was available from Wetland Bird Survey (WeBS) high and low tide counts, from the Somerset Ornithological Society and from the West Hinkley Wind Farm Planning Application, submitted in December 2006. 18.5.67 WeBS Core Counts for the five most recent available years and Low Tide Counts for the most recent available winter were obtained for count sectors within Bridgwater Bay. The locations of the Count Sectors are shown on Figure 18.27. 18.5.68 As can be seen with reference to Figure 18.27, the closest regularly counted core count area encompasses much of Steart Flats and all of Count Sector 5 used during the EIA specific surveys (see Figure 18.4), while the low tide count areas cover the entire extent of the intertidal survey area. 18.5.69 WeBS data indicates that several species forming part of the cited interest of the Severn Estuary SPA/Ramsar site use the intertidal area of Steart Flats immediately to the east of the main survey area at Hinkley. The WeBS data is summarised as follows (a fuller account is given in the bird report in Appendix 18d):
Peak counts during 2001/02 to 2005/06 inclusive, in WeBS Core sector 13411, which covers much of the Steart Flats, included 2,900 shelduck, 950 wigeon, 1,800 teal, 42 little egret, 320 ringed plover, 820 grey plover, 14,500 dunlin, 194 black-tailed godwit, 1,550 curlew, 85 whimbrel, 14 spotted redshank, 11 greenshank and 950 redshank. Numbers of teal, little egret, ringed plover, black-tailed godwit, whimbrel and spotted redshank show considerable between year variation;
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Low tide count data for 2002/03 for those sectors that form the western part of the Steart Flats (BV670 and BV690-4 inclusive) indicated that a number of species forming part of the cited interest of statutorily designated sites occurred in this area, including: 168 shelduck (across the sectors), 301 grey plover, 15,100 dunlin, 228 curlew and 72 redshank; Low tide counts conducted in Sector BV696 (which covers all of the EIA survey Count Sector 5) included: 70 shelduck, 90 wigeon, 30 pintail and 40 redshank; Very few birds were recorded in Low Tide sectors BV695, or BV697 which covers much the same area as the EIA surveys Count Sectors 1-4; and Of the other species forming part of the cited interest of local designated sites, Bewick’s swan, white-fronted goose, gadwall, pochard and tufted duck were not recorded on either Core Count or Low Tide counts during 2001/02–2005/06 and 2002/03 respectively, and only relatively small numbers of shoveler, ruff and water rail were noted. 18.5.70 A summary of information for species which do not form part of the cited interest of the local designated sites is as follows:
Peak counts of 23 cormorant, 160 oystercatcher, 1,950 golden plover, 58 bar-tailed godwit, 26 avocet, 1,050 knot, 100 sanderling, 120 turnstone and 3,500 black-headed gull were recorded in WeBS Sector 13411 (although counts of sanderling and turnstone showed considerable between year variation); and The low tide data indicated that good numbers of knot occurred on the Steart Flats in 2002/03 (combined peak count of 1,700 birds for sectors BV670, BV690-94 inclusive). Apart from a peak count of 43 oystercatchers in BV696, very few birds of non-cited species were recorded in WeBS count sectors within the intertidal survey area. 18.5.71 Somerset Ornithological Society provided records of birds within 3km of the Development Site boundary for the period 1997-2007 inclusive. Specific grid references and behavioural information was not included, and this data is therefore not considered to be detailed enough to inform the assessment given the other information available. 18.5.72 Intertidal survey was conducted in connection with the West Hinkley Wind Farm application (see Figure 18.20), submitted in December 2006. This comprised 12 survey visits between October to March 2003/04, a further 18 survey visits between August 2004 and March 2005, and six survey visits in March 2006. The survey area comprised the intertidal adjacent to the Wind Farm, plus a ‘substantial buffer’ to the east and west (extending approximately 2km to the west of the HPC Development Site and 1km to the east of the existing built nuclear plant). Intertidal survey results are summarised for wildfowl as follows (species forming the cited interest of local designated sites have been concentrated on):
The intertidal mudflat to the east of the power stations was found to support the largest concentration of wildfowl, with the largest numbers recorded around low tide; Small numbers of shelduck were also recorded on the foreshore to the west of the power stations, with numbers generally in the range of 1-15 birds, although in excess of 30 birds were noted on a number of occasions. Larger flocks were noted in the wider survey area e.g. 450 birds in September 2004; Teal were recorded infrequently during the 2003/04 and 2004/05 winter bird surveys but were seen in larger numbers in March 2006. Flocks of 20-50 teal favoured the area around the outfall of the operational plant (Hinkley Point B) and the open mudflats to the east of this; Shoveler were not recorded during the 2003/04 or 2004/05 winter bird surveys but small numbers including counts of 11 and 21 birds were with teal around the outfall and on the Hinkley Point CWS sewage pond in March 2006; A single count of 182 pintail was recorded on 20 October 2003 (in excess of 800m from the wind farm boundary) but no birds were recorded during the 2004/05 surveys. During March
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 41 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 2006, a smaller flock of pintail was present on mudflats to the east of Hinkley Point at low water (mean count 22 birds, peak count 70 birds); and Wigeon were concentrated around the outfall at Hinkley Point and on the mudflats to the east of the nuclear power stations. There were peak counts of 64 birds in winter 2003/04, 102 birds in winter 2004/05 and 124 birds in March 2006. 18.5.73 The surveys recorded the following information with regard to waders:
Curlew was regularly recorded during the winter surveys. There was some variation in numbers between the survey periods, and a peak count of 70 birds (across the survey area) was made on 20 March 2006. Curlew ranged across the entire area surveyed, favouring the intertidal mud to the east Hinkley B power station, but also occurring in small numbers in the intertidal adjacent to the Development Site; Other cited species were recorded in lower numbers: the highest count of ringed plover was 23 birds in December 2004. These birds were noted in Count Sector 1 of the survey area of the current application (an area of mobile sand with some rock). Black-tailed godwit and grey plover were recorded once during the 2006 surveys, but not during the preceding winters. Single redshank were noted in winter 2004/05 (within 800m of the wind farm) and March 2006; and Non-cited wader species included oystercatcher, purple sandpiper and turnstone. Of these only oystercatcher occurred with regularity. The overall peak count during the survey period was 77 birds in October 2004 (there was a further count of 69 in January 2005), with lower numbers recorded in winter 2003/04 (peak 45) and in March 2006 (50). Oystercatchers occurred throughout the survey area, and were less associated with intertidal mud than many of the other species. Flocks were recorded in Count Sectors 1, 3, 4 and 5 of the survey area for the current application. A mixed flock of turnstone (22) and purple sandpipers (25) roosting on rocks in front of Hinkley B on 27 December 2003 is considered to represent an unusual occurrence. ii) Intertidal Birds – Survey Data 18.5.74 In total, each of the five survey locations (Sectors 1-5) was visited on 182 occasions between April 2007 and March 2009. The survey at each of the five locations visited during the survey day lasted for 45 minutes, resulting in a total of 136.5 hours of survey per point and an overall survey effort of 682.5 hours. The physical characteristics of the count sectors are summarised in Table 18.5.5 below. Table 18.5.5: Characteristics of the Shore within the Intertidal Count Sectors
Count Description of Extent and Description of Extent and Sector Characteristics of Shore at High Characteristics of Shore at Mean Low Water Water
1 Approximately 10 to 20m of sand Approximately 350-400m of open shore generally remains exposed on the with large areas of sand bordered to the upper shore throughout much of the east by rock platforms and loose boulders. sector. A strandline, mainly Some pools are present in the rocky areas, consisting of Fucoid seaweeds is these being dominated by Fucoid present. The area of sand borders a seaweeds. supralittoral storm beach. The eastern part of the sector has more rock at high water than sand.
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Count Description of Extent and Description of Extent and Sector Characteristics of Shore at High Characteristics of Shore at Mean Low Water Water
2 Between 0 and 30m of exposed rock Slightly in excess of 200m of mainly solid platforms partially covered by areas rock platforms with some overlying large of pebble/boulder storm beach and a loose rocks. Some shallow gullies and strand line dominated by Fucoid pools dominated by Fucoid seaweeds. seaweeds.
3 A strip of between 0 and 10m of loose Approximately 400-450m of open rock boulders, some solid rock with platforms traversed by narrow east-west pockets of shingle and an bands of sand and mud and bordered by intermittent strand line. an extensive and dynamic area of open sand and mud in the western part of the count sector.
4 A boulder shore/storm beach of Approximately 400-450m of exposed between 0 and 15m in width, with a shore featuring a mosaic of areas of open brown seaweed dominated strand rock (particularly around the warm water line. A relatively linear band of sand outfall) and extensive mud covered by runs east from the survey location loose pebbles and boulders with some parallel to the coastal defence in pools front of the built nuclear power stations.
5 0 to 5m of sand with occasional Between 700 and 800m of very extensive boulders and a strand line following open mud. Patchy areas of rock on the neap tides. Some areas of boulder upper reaches of shore and in the western shore/storm beach in the western part of the count sector. part of the sector.
18.5.75 Detailed survey results are provided below for those species forming the cited interest of the SPA (including SPA Review species) and species cited in the Ramsar description. SSSI species and additional species noted in the Ramsar description as occurring in numbers of national importance are also covered in detail. Accounts of other species have been summarised, based on conservation status, frequency of occurrence and flock size. 18.5.76 Table 18.5.6 provides a summary of the results obtained from the intertidal surveys undertaken between April 2007 and March 2009 inclusive. The figures show the peak number of each species recorded in each count sector (excluding counts of birds flying through the area). For each species a description of the level and type of use (foraging, roosting, etc.) in each count sector is also provided.
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Table 18.5.6: Level and Type of Use by Each Bird Species in Each Count Sector
Species Status12 Peak Count in Each Count Sector Type and Level of Use (2007-09)
CS1 CS2 CS3 CS4 CS5
Shelduck SPA, 33 500 200 71 700 Shelduck were recorded on a Ramsar, regular basis throughout the survey SSSI period, with the largest numbers occurring between July and September inclusive. The largest numbers of foraging birds were recorded on the mudflats in CS5 at low water, with smaller numbers regularly seen in CS4. CS1, 2 and 3 received relatively low level use by this species. Congregations of birds were seen loafing on the sea in all count sectors during high water although no regular onshore roost sites were identified.
Wigeon SPA(a), 39 17 67 220 204 Wigeon were recorded consistently SSSI during the autumn and winter, with the largest numbers between the months of November and February inclusive. The largest numbers of foraging birds were recorded in CS4 and CS5, with low level use in the other count sectors. Congregations of loafing birds were noted at high water in CS4 and CS5, although no regular roost sites were found.
Teal SPA(a), 0 1 0 25 14 Teal were recorded very sporadically Ramsar(f), during the survey period (on a total SSSI of five survey dates), with none noted during the second survey year (April 2008 to March 2009).
Mallard SPA(a) 3 4 3 32 51 Relatively low level use by mallard was recorded in all months of the year, and throughout the survey area, with the largest numbers of
12 Status: (SPA) species that are designated for their populations of European importance in the Severn Estuary SPA, including those listed in the SPA Review, Stroud et al., 2001, those listed only in the waterfowl assemblage designation for the SPA are denoted by (a); (Ramsar) qualify under Criterion 6 for the Severn Estuary Ramsar site, with those listed as possible future qualification are denoted by (f); (Notable) species listed as notable interest for their nationally important populations in the Severn Estuary Ramsar site description, and (SSSI) species that appear in the citation for the Bridgwater Bay SSSI for their populations of at least national importance.
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Species Status12 Peak Count in Each Count Sector Type and Level of Use (2007-09)
CS1 CS2 CS3 CS4 CS5 foraging and loafing birds in CS4 and CS5.
Pintail SPA, 0 4 60 35 48 Pintail were recorded on a regular Ramsar (f) basis between the months of September and March inclusive. The majority of foraging birds were seen in CS4 and CS5 at low water, with birds moving onto the sea nearby to loaf at high water. There was an intermediate level of use in CS3, low level use in CS2 and no pintail recorded in CS1. No regular roost sites were identified.
Shoveler SPA(a) 0 0 4 0 4 Use of the survey area by shoveler was infrequent (all during winter), and no large flocks, roosting or foraging birds were recorded.
Ringed Plover SPA, 33 16 4 10 4 Ringed plover were recorded in all Ramsar (f) months of the year, with foraging associated with the open mobile sand in CS1, with most roosting birds also recorded in this sector. Low level use was recorded in the other count sectors.
Grey Plover SPA(a) 3 1 0 0 0 Occurrence of grey plover was very sporadic (recorded on two survey dates).
Lapwing SPA(a) 2 0 35 3 102 The vast majority of lapwing were recorded (roosting and foraging on intertidal habitat) in CS5 between the months of November and February inclusive, with very low level use in the other count sectors.
Dunlin SPA, 7 13 0 0 9 Dunlin were recorded foraging on Ramsar, intertidal habitat sporadically in SSSI small numbers, primarily during the autumn passage period between July and September inclusive. One roosting bird was noted on one date.
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Species Status12 Peak Count in Each Count Sector Type and Level of Use (2007-09)
CS1 CS2 CS3 CS4 CS5
Black-tailed SSSI 0 0 0 0 100 Infrequent use of the survey area Godwit was recorded by black-tailed godwit (only in CS5), with birds tending to occur in flocks when present.
Whimbrel SPA(a), 1 5 1 4 16 Whimbrel were predominantly SSSI recorded during the spring passage period, with most birds noted between mid April and mid May. Return passage (in smaller numbers) was recorded in July and August. Foraging birds were noted in all count sectors, although the vast majority were in CS5.
Curlew SPA, 16 24 25 41 63 Curlew were consistently recorded Ramsar(f) throughout the survey period. Numbers were lowest between April and June, being considerably higher during other months of the year. The open mud in CS5 attracted the majority of foraging birds and roosting was mainly recorded in CS4.
Redshank SPA, 1 1 1 1 22 Redshank were recorded Ramsar intermittently in very small numbers throughout the survey period. Redshank were most consistently seen foraging on intertidal habitat in CS4 and CS5, with few records from the other count sectors.
Little Egret Notable 3 6 3 6 6 The largest number of little egrets were most consistently recorded between August and October followed by a decline in numbers and occurrence in the first few months of the year. In each Count Sector, 1-2 birds were frequently present in CS1 and CS2, 1-3 birds in CS3, 1-4 birds in CS4 and 1-5 birds in CS5.
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Species Status12 Peak Count in Each Count Sector Type and Level of Use (2007-09)
CS1 CS2 CS3 CS4 CS5
Herring Gull Notable 170 187 350 280 150 Herring gull was the most abundant gull species during the intertidal surveys, with large numbers of birds seen in all count sectors. A high proportion of records relating to loafing birds (on rocks, the shoreline, intake tower and power stations) or individuals commuting along the shoreline.
18.5.77 Results from the intertidal surveys undertaken in 2007-09 indicate that Count Sector 5 (and to a lesser extent Count Sector 4) provide an important foraging resource to shelduck, curlew and little egret (throughout much of the year), to pintail and wigeon during winter and to whimbrel, primarily during spring passage. Intertidal habitat in Count Sector 1 was identified as a regular roost site for ringed plover, and that in Count Sector 4 for curlew. f) Coastal Field Birds - Desk Study Information 18.5.78 A series of field walkover surveys were conducted over successive winters in connection with the West Hinkley Wind Farm application (see Figure 18.20), submitted in December 2006. Survey effort included 12 survey visits between October 2003 and March 2004, a further 18 survey visits between August 2004 and March 2005, and six survey visits in March 2006. The survey area comprised all of the fields within the proposed wind farm site, plus a perimeter area extending to (approximately) Little Dowden Farm in the east and Newnham Bridge and Burton to the south. The area surveyed extended at least 1.5km to the west of the Development Site boundary. 18.5.79 The following information has been summarised from the survey work undertaken for the West Hinkley Wind Farm ES:
Small numbers of shelduck were recorded on an occasional basis in the coastal fields; Teal was noted on ponds to the south of the power stations (around the Sewage Works). Some interchange was recorded between the ponds and the foreshore; A few shoveler, associated with the teal, used the same ponds and area of foreshore; At least two peregrine were seen with regularity during the winter months; A minimum of two merlin were recorded in the survey area in winter 2006 (although the species was not seen in winter 2003/04); There are few notes on gull flocks, and figures provided with the EnvApp indicate low numbers in the terrestrial parts of the survey area. The only record specifically mentioned involves 63 black-headed gull and 15 common gull foraging in a freshly ploughed field within the survey area in early March (2006); There was one record of oystercatcher using coastal fields, with all other records of the species being confined to the intertidal; It was concluded that there was no regular use of the coastal fields by curlew; Little egret were most frequently recorded on Wick Moor; and Flocks of golden plover (peak 332) and lapwing (peak 106) were recorded in arable fields within the wind farm and on Wick Moor respectively in March 2006. These records coincided with a period of very cold weather. There were a small number of additional
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 47 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology counts in excess of 100 birds (of both species) over the survey period. This sporadic occurrence of relatively large flocks was considered to reflect the fact that birds moved into the area in cold weather and as a result of more local movements associated with the known flock at Pawlett Hams (Burton, 2003). i) Coastal Field Birds - Survey Data 18.5.80 Field surveys began in September 2007 (with the frequency increased in November 2007) and continued through until March 2009. A total of 72 surveys were undertaken during the survey period. Generally the survey was completed during one day, but when poor weather conditions made this unachievable the next available opportunity (usually the following day) was used to complete the work. 18.5.81 The most notable results of the field surveys (those concerning species forming part of the cited interest of the designated sites) were as follows:
Shelduck was recorded on 2 dates in winter 2007/08 and 1 date in winter 2008/09 (3 birds were noted feeding in Field 1 on 11th and 14th March 2008 and 4 birds were in Field 2 on 22nd December 2008). Field usage was highest in May and June 2008, when records included 20 birds in Field 13 on 8th May and 16 birds in Field 3 on 12th June; The pool, immediately east of the sewage works was the only water body in the survey area to regularly support wildfowl (predominantly teal and mallard). Small numbers of mallard (1-8 birds), which is a Severn SPA assemblage species, were seen on a regular basis in fields and ditches, and on the pool to the east of the sewage works. A gadwall was also recorded using the pool on a single date. The more notable counts of teal using the Sewage Works pool included 70 birds on 15th January and 40 birds on 25th January 2008 and 110 birds on 21st January and 70 birds on 6th and 18th February 2009. Elsewhere, up to six teal were seen in ditches to the south of the Power Stations in winter 2008/09; Small numbers of curlew (typically 1-14 birds) were recorded with relative regularity between October and March. The more notable counts were 21 curlew on Wick Moor (Field 81) on 21st December 2007, and 20 birds foraging in Field 17 on 21st January 2009. Coastal arable fields to the west of the operation plant were favoured (particularly Fields 1, 2, 17 and 39), with birds noted very sporadically elsewhere; Other waders included a single redshank in Field 16 on 10th January 2009 and 3 whimbrel loafing in Field 2 on 8th May 2008; Little egret was recorded with regularity during the surveys. The ditches around Wick Moor were the favoured foraging area, with egrets also seen occasionally in fields to the north of Myrtle Farm (Shurton). There was a peak count of eight birds feeding in Field 92 on 22nd October 2008 (with 8 birds commuting through this field on 4th December); Water rail was recorded on 2 dates in February 2009 in ditches/wetland habitat to the south of the existing power stations; and In winter 2007/08 flocks of in excess of 50 foraging lapwing (an SPA assemblage species) were recorded on four dates in the southern and south-eastern parts of the survey area (associated with winter sown cereals and pasture). The peak count was of 67 birds in Field 48 on 16th November 2007. In winter 2008/09 lapwing records were concentrated around Wick Moor and in fields in the central section of the Development Site. A total of 88 lapwing were recorded in two fields on 6th February and 161 across five fields on 7th February (survey split due to weather). The coastal fields (subject to permanent land take) did not regularly prove attractive to lapwing, with a total of 125 birds spread across several fields on 10th January 2009 being exceptional. 18.5.82 Notable records of non-cited species included the following:
Golden plover was infrequently noted during daylight hours in winter 2007/08 (4 single figure records). More sightings were made in winter 2008/09, with the species commonest
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology between late January and mid March 2009 (14 foraging flocks were noted on 5 dates). Records included counts of 30 foraging birds in Field 26 on 10th January, and a total of 98 and 127 birds recorded primarily in two areas (Field 17 and Fields 31/37/48) on 6th and 7th February respectively; The largest count of snipe was 20 birds in Field 13 on 10th January 2009, with 10 birds loafing in Field 37 on 11th December 2008 also of note. All other records were of 1-3 birds and there were no other dates on which the cumulative survey total exceeded 10 birds. Snipe were most commonly recorded around the ditches on Wick Moor; Flocks of herring gull were frequently recorded, with 5 records of 100+ birds between April 2008 and March 2009. No counts of black-headed gull in excess of 100 birds were recorded, and numbers of other gull species were rather low; In winter 2007/08 there were 10 records of peregrine (a minimum of 2 birds were present) and 6 of merlin during the field surveys. Between April 2008 and March 2009 merlin was recorded on a further 6 winter dates, with 1-2 peregrine seen on 15 occasions throughout the period (often loafing on the built plant or hunting in close to it). Other raptors included a commuting marsh harrier on 14 August and hobby on 20 May and 9 July 2008; and Kingfisher was recorded on 7 winter survey dates in the wetland habitat to the south of the built plant. 18.5.83 The survey work also allowed some data on the winter passerine community to be gathered. The more notable records are summarised below:
The large coastal arable fields in the western part of the survey area tended to support the largest number of skylark. A total of 600-700 birds were counted across fields 17, 21, 22, 23, 27 and 28 on 7th February 2009, and 300 birds remained in this area on 11th February 2009. Notable records from winter 2007/08 included 120 skylark in Field 1 on 21st December and 10th January; 150 skylark in Field 17 on 17th January (one of four counts of in excess of 100 skylark in this field in January 2008); 70 birds in Field 26 on 7th February 2008 and 80 birds in Field 1 on 18th February 2008; Meadow pipit numbers were highest between January and March 2008, with a peak count of 95 birds foraging on pasture (Field 84) on 17th March; Cetti’s warbler was recorded throughout the survey period, singing from reedy ditches bordering fields 66 and 89, and in scrub near the sewage works; Flocks of foraging wintering thrushes were recorded on an occasional basis, including 300 fieldfare in Field 65 on 20th November and 110 redwing in Field 45 during 6-7 February; Starlings were generally associated with pasture and included flocks of 100-350 foraging birds in the fields around Wick Moor; Flocks of linnets were a feature of the winter passerine community, with flocks recorded across the survey area. The peak count was 250 birds in Field 1 on 21st September 2007. Linnets were most regularly recorded in Fields 14-17, with a peak count of 140 birds in the latter field on 15th November 2008 and regular flocks of 30-80 birds ranging across the area; Yellowhammer numbers were low throughout, with a peak of 25-30 birds in the Myrtle Farm area in winter 2007/08; and Uncommon wintering and passage birds included a black redstart on the seawall near Hinkley Bridge on 22nd December 2008, and a firecrest in the hedge adjoining Fields 32/30 on 18th March 2009. 18.5.84 Figures 18.28 and 18.29 show the locations and numbers of species recorded during the field surveys that form the cited interest (or are mentioned as part of the assemblage or supporting interest) of statutory designated cited within 5km of the Development Site. Detailed results, including the dates of all surveys undertaken, are provided in the reports in Appendix 18d.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 49 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology ii) Nocturnal Surveys 18.5.85 A total of 26 nocturnal surveys were undertaken between December 2007 and March 2009 (between December 2007 – May 2008 and August 2008 and March 2009). Due to the limitations of even the most sensitive of night vision equipment, and the difficulties in locating small waders hidden in tidal creeks at night, the counts obtained from the intertidal survey are indicative, as is behaviour assigned to all of the species recorded during the survey work. 18.5.86 These surveys provided no evidence to suggest that the fields or adjacent upper intertidal habitat were being regularly used by large numbers of roosting or foraging birds, although consistent use of the coastal fields by small numbers of golden plover, a concentration of foraging snipe in Field 66 and regular use of Count Sector 1 by moderate numbers of roosting oystercatcher was recorded. Figures 18.30 and 18.31 show the approximate locations of species recorded during the nocturnal surveys that form the cited interest (or are mentioned as part of the additional interest) of statutory designated cited within 5km of the Development Site. Detailed results are provided in Appendix 18d. 18.5.87 The more notable results of surveys in winter 2007/08 (December 2007 – March 2008) were as follows:
The most notable wader counts involved roosting oystercatchers in Count Sector 1. Peak counts were 100 birds on 24th January 2008 and 65 birds on 21st February 2008; A total of 19 shelduck were roosting in Count Sector 1 on 24th January 2008; Small numbers of other species were recorded in the intertidal count sectors (maximum counts are in parentheses): mallard (1), wigeon (4), grey plover (1), ringed plover (4), turnstone (1), curlew (1) and redshank (1); Small numbers of golden plover (1-8 birds) were recorded during all the nocturnal surveys in arable fields and pasture adjacent or close to the seawall in the western part of the survey area. The frequency of golden plover records from the nocturnal surveys was appreciably greater than that for the daytime field surveys, indicating that the survey area was probably being used by small numbers of foraging and/or roosting birds; Very small numbers (1-3 birds) of lapwing were recorded on a regular basis in pasture to the south of the power station in the eastern part of the survey area; Small numbers of snipe were recorded on all visits, again in pasture areas, but also along ditches to the south of the existing Power Stations, with the largest count involving 15 birds in Field 66 on 21st February 2008; and A barn owl was seen over Field 85 (part of the Hinkley CWS) on 17th March 2008. 18.5.88 The more notable results of surveys conducted between April 2008 and March 2009 (April & May 2008 and August 2008 to March 2009) were as follows:
Roosting flocks of 20-80 oystercatcher were recorded on 11 dates (55% of surveys) in Count Sector 1; Roosting flocks of 20-24 shelduck were recorded on three dates (10th and 13th December 2008 and 10th January 2009) in Count Sector 1; In the intertidal, small numbers of golden plover, lapwing, redshank, dunlin, snipe and turnstone were noted infrequently during the survey period. Ringed plover (small numbers heard within the intertidal area and not seen), grey plover, turnstone and curlew were noted on a more regular basis (11, 5, 5 & 13 dates respectively); Golden plover were recorded in fields within the survey area on a regular basis (on 9 dates), particularly in Fields 17 and 2. Peak counts included 21 foraging and loafing golden plover in Field 2 on 10th December 2008 and 13 foraging birds in Field 17 on the same date. The total number of golden plover counted on any one date, rarely exceeded 15 birds, but included 37 birds counted on 10th December 2008 (the peak count for the site) and 19 birds on 10th March 2009;
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Lapwing were noted (in scattered locations) on eight dates, including 14 birds in Field 60 on 10th January 2009 (with an overall total of 55 birds in all fields on that date); Snipe (usually 1-3 birds) were flushed from ditches in and around Wick Moor on a total of 13 dates between September 2008 and March 2009. The largest counts of snipe all came from Field 66 (North Moor), and included 12 birds on 10th December 2008, 20 birds on 13th January 2009 and 15 birds on 6th February 2009; Whimbrel was heard calling from the intertidal zone on 14th April and 14th August 2008; Small numbers of wigeon (1-2 birds on 3 dates), teal (1-2 birds on 3 dates) and mallard (up to 9 birds on 5 dates) were also recorded in fields, particularly on Wick Moor; A barn owl was seen loafing in Field 7 on 21st August; and Other species recorded were singing Cetti’s warbler (in Fields 60, 64 and 80) and nightingale (in scrub around Field 87 and west of the sewage works) during April and May 2008. iii) Trends in Ornithological Interests of Designated Sites 18.5.89 The collection of WeBS Data allows conclusions to be drawn at estuary level with regard to short term (5 year), medium term (10 year) and long term (25 year or maximum available period) trends in the numbers of individual qualifying and assemblage species. These results have recently been subject to detailed evaluation for estuarine SPAs and SSSIs across the UK (Maclean & Austin, 2008). The aim of this work is to establish a framework that can be used to alert conservationists to ‘real’ declines in bird populations that require targeted action (as opposed to natural fluctuations). 18.5.90 Summarised data indicating trends in local waterbird numbers up to and including the winter of 2006/07 (thus partially updating Maclean & Austin, 2008) is available at the following web address: http://www.bto.org/webs/alerts/alerts2008/Results/UK9015022/severnupdate.pdf Additional information, summarising results of survey work at the national level, and including detailed species accounts is provided in Annual Webs Reports. At the time that this EnvApp was produced the most recent available information was Waterbirds in the UK 2006/07, which summarises data between April 2001 and March 2007 (Austin et al., 2008). 18.5.91 The qualifying number of birds in the respective SPA and Ramsar assemblages are quoted as being 84,317 and 70,919 individuals respectively13. WeBS data for the most recent five years (between 2001/02 and 2006/07 indicates a peak mean population of 68,769 birds in the estuary. The effect on the baseline level of use of the survey area at Hinkley of a decline in numbers of birds using the estuary will depend on population dynamics and distribution of individual species. As a result it is probably better to consider predicted trends on a species rather than assemblage level. 18.5.92 The data indicates that sustained declines (of 35-76% since designation) have occurred within the Severn SPA (i.e. within the site rather than the SPA species themselves) in the following species: Bewick’s swan, white-fronted goose, pochard and dunlin (although there has been a short term partial recovery in Bewick’s swan numbers). In contrast, shelduck, wigeon, gadwall, pintail, shoveler, tufted duck and redshank have shown sustained increases (8-124% respectively14), while numbers of other species have fluctuated, with curlew showing an 18% (net) decrease and mallard and teal showing respective 24 and 28% net increases since designation. Lapwing numbers are considered to have remained stable during the period (Maclean & Austin, 2008).
13 The SPA and Ramsar Citations indicate that the Ramsar information is the more recent. This takes into account bird information available up until the end of winter 2002/03. The SPA information sheet was last updated in February 1999. 14 The largest increases since designation have been shown by shoveler (+124%), pintail (+67%) and wigeon (+20%), with the largest decreases noted in white-fronted goose (-76%), Bewick’s swan (-41%) and pochard (-55%).
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 51 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.93 The declines in white-fronted goose and Bewick’s swan seem unlikely to be reversed in the short term, as they have been linked to wider climatic change. Numbers of wintering white- fronted geese in the UK were at their lowest ever recorded level in 2006/07, and while this may in part reflect lower numbers due to poor breeding success, the main reason is that the centre of distribution of the wintering population is shifting gradually eastwards. There is also evidence to suggest that Bewick’s swans too are remaining further east and those that are coming to the Severn are staying for a shorter period before moving back east (Austin et al., 2008). This suggests that it is unlikely that either species (neither were been recorded during the survey work) will make greater use of the area in the foreseeable future. 18.5.94 The five-year peak mean of wintering shelduck recorded in the Severn SPA between 2001/02 and 2006/07 (3,492 individuals) was broadly similar to the qualifying number quoted in the SPA citation (3,330 birds). At national level there was a decline in wintering numbers during the 1990s, and overall numbers are relatively low at present (e.g. the peak combined UK site count for 2006/07 was the lowest for 30 years) (Austin et al., 2008). Recent counts indicate that the population may now be stable, which suggests that the baseline information collected for the site is relevant to at least the short term situation. If further population trends emerge, any perceptible changes (which given inter-annual variation in use would be very difficult to detect) would be most likely to affect shelduck numbers in, or frequency of use of, Count Sector 5. 18.5.95 Fluctuations in the wigeon population may become more evident over time, as mild winters are likely to result in a larger number of birds remaining in the North Sea and the Baltic. The winter of 2006/07 was particularly poor for wigeon at the national level. Despite this, however, numbers increased in the Severn Estuary (Austin et al., 2008). If this trend were to continue, then the Severn would become a proportionately more important wintering area for this species, and larger numbers of birds would be expected in regularly used parts of the survey area (Count Sectors 4 and 5). Shoveler, which has undergone a considerable increase in the Severn since the designation of the SPA, has been present in internationally important numbers during the most recent winters for which data is available (2005/06 and 2006/07) (Austin et al., 2008). This suggests that the species could be added to the main qualifying interest of the SPA and Ramsar Site at the next review. Numbers recorded during the baseline survey work have been very low, however, and it is unclear if any increase at the estuary level would result in the species making greater use of the area around Hinkley. It would be expected that any increases would be more obvious in parts of the SPA where shoveler already occur (such as along the River Parrett). 18.5.96 Numbers of wintering pintail have been subject to long term increase at national level, although recent fluctuations make the current population trend difficult to discern. At the estuary level, the five-year mean and the peak count of 1,161 individuals in January 2007 (Austin et al., 2008) are both well above numbers quoted in the SPA Review. Gadwall, in contrast, has shown a recent decline in numbers at both national and estuary level. The 5-year peak mean of 255 individuals is almost 10% lower than the numbers when the site was designated (Austin et al., 2008). 18.5.97 Teal numbers have been subject to recent fluctuations (following a period of increase), and current population trends at UK level are unclear, although the peak count in the Severn in 2006/07 exceeded that in three of the previous 4 winters. Given these results, it seems reasonable to assume that use of Count Sectors 4 and 5 by pintail is likely to remain similar or to increase, that future levels of use of the local area by teal will remain relatively constant or decline, while the frequency of occurrence of gadwall (which was recorded on only one occasion in 2 years of survey work) is unlikely to increase in the foreseeable future.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.98 Wintering mallard numbers have been in steady decline at national level for a number of years. The reasons for this decline are not fully understood, although various theories have been postulated that might account for it (including a decline in immigrant birds and fewer captive- bred birds being released). It is unlikely that this national decline, if reflected on the Severn, would result in a clearly perceptible change in numbers of birds recorded within the survey area. 18.5.99 Dunlin numbers have been in long term decline in the UK, and in winter 2006/07 the total recorded was at the lowest level since 1970 (when far fewer sites were counted). This decline is reflected in the peak count for the Severn of 16,625 individuals in December 2006 and the current 5-year peak mean of 21,430 birds (over 3,500 birds less than are listed as occurring in the Severn Ramsar Site description). Assuming these trends are continued, it is unlikely that there would be a perceptible change in use of the survey area by dunlin (due to the very low levels of use recorded during the baseline work). 18.5.100 Whimbrel numbers also appear to have fallen considerably in comparison with the population level quoted in the Ramsar description (333 individuals), with a peak mean of 189 for the past 5 years, and no individual annual counts exceeding 240 birds. If a continued downward trend is assumed, over time it would be expected that numbers of birds recorded in Count Sectors 4 and 5, where they were most regularly recorded during baseline work, would fall. 18.5.101 Curlew numbers are currently considerably lower in the Severn SPA than are quoted in the Ramsar citation (3,903 individuals). However, the 5-year peak mean of 2,974 birds is still clearly in excess of the number of individuals quoted in the SPA Review (2,021), which recommended that curlew be elevated to SPA qualifying species status. Against a national background of 5 years of decline in curlew numbers (between 2000/01 and 2005/06) which has only recently started to “bottom out”, this suggests that curlew should be added to the main qualifying interest of the SPA and Ramsar Site at the next review. Given the apparent short term stability in terms of numbers, use of the survey area is likely to remain relatively consistent with that recorded during baseline work, with the greatest use occurring in Count Sector 5. 18.5.102 Redshank numbers appear to have remained relatively stable since the SPA was designated, as the most recent 5-year peak mean is 2,312 individuals (and the SPA qualifying population is listed as 2,330 birds). Against a recent background of falling numbers at the UK level, this suggests that a stable population in the Severn Estuary would become proportionately more important over time. Given the very limited use of the survey area around Hinkley, however, this is unlikely to have a bearing on the assessment. 18.5.103 Passage ringed plover numbers fluctuate considerably between years, although some incongruities in the WeBS data may reflect the fact that counts do not necessarily always coincide with the relatively short periods when peak numbers are present. On the Severn a count of 1,453 individuals in August 2006 was more than double the peak count for 2005. This indicates that passage ringed plover numbers can comfortably exceed SPA qualification levels, and that the species could potentially be added to the SPA and Ramsar Citations at the next review. In terms of the Hinkley area, it is likely that in years when numbers of this species on passage are high there will be a higher incidence of activity in Count Sectors 1 and 2. 18.5.104 WeBS Data indicates that the Severn is clearly of national importance for black-tailed godwit (the national threshold of importance is 150 birds), as the 5-year peak mean count is 383 birds. Indeed during winter 2003/04 the peak count of 540 black-tailed godwit on the Severn exceeded the threshold of international importance (470 birds). Over the course of the baseline survey work in the Hinkley area, however, black-tailed godwit was recorded extremely sporadically and in variable numbers, and in this context it is not considered that an upward
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 53 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology trend in numbers at either UK or estuary level would necessarily be detectable against the background level of low and infrequent use. 18.5.105 It is acknowledged in the WeBS report that trends in lapwing numbers cannot be inferred from the data gathered. Spotted redshank, greenshank, ruff and water rail have not been considered here due to the very low incidence or complete absence of records during the baseline work. It should also be noted that reliable interpretation of trends in gull numbers based on WeBS data is not possible (as counting gulls is optional during counts), and has not been attempted here. g) Bats i) Desk Study Information 18.5.106 Regular bat surveys have not been undertaken by the BE Site Warden, although common species such as pipistrelle (the species of pipistrelle does not appear to have been determined) and noctule are known to occur through ad hoc surveys using bat detectors (Burrell, 2006) (Ref. 18.33). 18.5.107 SERC records were interrogated following the receipt of an updated search (for 3km around the Development Site boundary) in May 2009. The more notable records in the immediate area are as follows:
There are four reports of grey long-eared bat listed between 1996 and 1998 all from grid reference ST207458 (near or in the plant training building); There is one record of lesser horseshoe bat. The species was recorded in flight at ST206 455 on 28 September 2006. This is within the Development Site boundary close to the east- west Green Lane. The origin of this record is unknown; and Brown long-eared bat, noctule and serotine are listed as being occasional, frequent and rare respectively at ST200456, recorded between 28th June and 28th September 2006. This location is within the coastal part of the site. 18.5.108 A 10km search for bat records was conducted to gain insight into bat activity in the wider area, particularly roost locations and records of nationally rare species/those with a restricted range known to occur in Somerset. The most notable results were as follows:
There are no known barbastelle roosts and no records of the species within 10km of the Development Site; There are five lesser-horsehoe bat (a West Somerset BAP species) roosts (both summer and hibernation) between 7.5km and 10.2km of the site. These roosts are all in the Quantock Hills; The furthest of these lesser horsehoe bat roosts from the site (10.2km south south-east) also supports greater horseshoe bat; and The closest brown long-eared bat roost is approximately 2.8km to the south-east of the Development Site at ST237 428. There are two further roosts between 8 and 10km of the site. 18.5.109 Additional information was sought from the Recorder for Somerset Bat Group with regard to the records of grey long-eared bat, as SERC were unable to obtain further details with regard to authenticity or origin. The Recorder stated that there is one confirmed record of a grey long- eared bat from Hinkley. This animal was found in the administration block of the operational plant and taken into care. 18.5.110 Bat surveys were conducted for West Hinkley Wind Farm application during 2005 and 2006 (Dulas Ltd, 2006) (Ref. 18.3). Roost surveys were undertaken of 3 of the 4 buildings and all suitable mature trees. Transect surveys were completed to record bat activity within the Wind Farm site. The surveys undertaken encompassed all suitable roost trees within the boundary of the HPC Development Site.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.111 Bat droppings (species not specified) were found in one of the four agricultural buildings surveyed in 2005 but no evidence of bats were found during repeat surveys in 2006. The EnvApp concluded that none of the buildings were used as maternity roosts, but that small numbers of bats might use the buildings occasionally for shelter or hibernation. 18.5.112 Limited numbers of mature trees were found to be present within the Wind Farm survey area, and these were climbed so that evidence of bats could be searched for. No tree roosts were found. A number of transect routes were walked on several occasions during 2006 (between the 28th June and 3rd August). The presence of the following species was recorded: common and soprano pipistrelle, noctule, serotine and bat species in the genus Myotis. Common pipistrelle was the commonest species and was recorded on all survey dates. There were no barbastelle records from the Hinkley area during the surveys undertaken for the Wind Farm application. Bat activity appears to have been spread throughout the Wind Farm survey area. 18.5.113 Supplementary post-submission information for the Wind Farm application was collected in April and May 2007 by Michael Woods Associates, to a survey protocol agreed with West Somerset Council. This involved survey visits on the 2nd April and 2nd May, during which three surveyors walked separate transects, all of which overlapped the HPC Development Site boundary, and one of which was entirely within it (the entire east-west Green Lane was covered during each survey). Each survey resulted in 10.5 hours of data being collected from areas within and adjacent to the HPC Development Site boundary. The agricultural buildings on site were also visited to be assessed for roosting potential and static anabats were deployed at three locations (all within the Development Site) to collect complementary data. 18.5.114 These 2007 surveys concluded that the coastal fields had relatively little bat activity and that there was no evidence of roosting within the buildings. Five bat species were recorded during the work: common and soprano pipistrelles, noctule, lesser horseshoe bat and at least one Myotis species. Pipistrelles were recorded on all surveys, with other bat species being far less frequent (only a small number of records and not recorded during all surveys). The report identified that several localised sections of hedgerow, including two along the east-west Green Lane, appeared to be of local importance to bats. 18.5.115 Barbastelle are listed in the Vale of Taunton and Quantocks Fringes Natural Area Profile (English Nature, 1998) (Ref. 18.34) as a species that has been recorded several times in recent years. This Natural Area occupies the low ground between the Quantock Hills, the Brendon Hills and Exmoor and the Blackdown Hills and extends east of the Quantocks to meet the Somerset Levels. It is bordered to the north by the Bristol Channel Coast. As such, it encompasses the HPC Development Site. ii) Survey Data 18.5.116 Walked transects conducted in 2007 concentrated on the coastal fields to the north of the east- west Green Lane. These surveys were conducted on a monthly basis between June and September inclusive and resulted in the following species being recorded: common pipistrelle, long-eared bat (probably brown long-eared bat), noctule and barbastelle. 18.5.117 Common pipistrelle was the most frequently recorded and widely distributed species during the walked transects. The number of common pipistrelle passes recorded on any one night ranged from four on 26th June to 19 on 23rd July. Common pipistrelle activity, which comprised both commuting and feeding, accounted for 100% of the total bat activity recorded within the survey area on 22nd August. The highest levels of bat activity, as indicated by the number of discrete series of echolocation calls (often referred to as a bat pass), were around hedge lines and scrub and were frequently associated with foraging activity. Four locations were identified between the coast and the Green Lane that had locally elevated levels of use.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 55 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.118 The Green Lane was also the location of the long-eared bat activity, which was recorded on 26th June. Two long-eared bats were observed by the surveyors flying between the hedgerows and appeared to be foraging. 18.5.119 The recordings of noctule were concentrated along the access road into Hinkley Point power station. Several were seen foraging around the lights running along the plant approach road on 23rd July. 18.5.120 Barbastelle was encountered twice on the east-west Green Lane on 23rd July. 18.5.121 Static Anabats deployed in coastal fields within the Development Site boundary for single nights in June. July and September 2007 did not record bat activity. A static Anabat located at ST216 457 (near to Pixie’s Pond) on 23 July recorded 4 species: Daubenton’s bat, soprano pipistrelle, common pipistrelle, and (potentially) a further Myotis species. 18.5.122 Driven transects were undertaken in July and August 2007 to gain greater context with regard to the local bat community and their likely commuting routes. The surveys began at the power stations and extended to Stogursey in the south, Stolford in the east and Cross Elms Copse CWS in the west. Species recorded were: common pipistrelle, soprano pipistrelle, a long-eared bat species, serotine, noctule, barbastelle and a Myotis species:
Five species of bat, including barbastelle, were recorded at Cross Elms Copse, approximately 1.8km to the west of the Development Site boundary. Hedgerows connect this copse to a number of small woodlands and plantations, including Honibere Woods, Martin’s Wood and Great Plantation; Serotine and noctule were recorded around the village of Wick, Upper Cock Farm, Brown’s Cottage (to the east of Hinkley Point power station) and close to the power station on Wick Moor Drove. However, the level of bat activity in this area was generally lower than in areas to the west. 18.5.123 Additional walked transects undertaken in coastal fields in September 2008 recorded common pipistrelle and a Myotis species. Pipistrelle behaviour included commuting and foraging, with groups of up to three bats recorded on both visits. Some activity was recorded around the stone barns, although no social calls were heard, and there was no evidence to suggest a roost was present. Two passes by Myotis species were recorded during the second visit. These animals were recorded a considerable time after dusk. 18.5.124 The 2009 bat surveys recorded at least nine species of bat using the Development Site, these are; common pipistrelle, soprano pipistrelle, noctule, serotine, long-eared (likely to be brown long-eared), Myotis sp (likely to be at least Natterer’s and Daubenton’s based on call characteristics and habitats present), barbastelle, lesser horseshoe and greater horseshoe. 18.5.125 The majority of the bat activity recorded during the 2009 surveys occurred along the woodland edges, hedgerows and through the valley in the centre of the Development Site. This can probably be attributed to general bat behaviour (using features for shelter and to avoid predators) in combination with the character of the landscape, which is exposed and largely influenced by intensive farming practices. 18.5.126 Both commuting and foraging behaviour was recorded, suggesting the hedgerow network through the site is used by bats travelling between roosts and foraging locations. Feeding buzzes from both pipistrelle and Myotis species were also recorded and foraging can be inferred from the behaviour seen relating to noctule, serotine and barbastelle (i.e. a number of passes in quick succession along a feature). 18.5.127 The number of registrations and the location of these throughout the survey area indicate that all of the species recorded, apart from the horseshoe and long-eared bats, occur frequently
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology throughout the site. Further, it is likely that the long-eared bats have been under-recorded (due to their quiet call) and also occur frequently. 18.5.128 The number of barbastelle records within the Development Site was much greater in 2009 than in previous survey years. The most likely explanation for this is not that usage of the site has increased, but rather that the extensive survey effort and presence of recording devices within the site during 2009 provided more opportunity to encounter this species. Even with more records it is still difficult to fully determine how barbastelle use the site, some broad observations can be drawn, as follows.
Whilst barbastelle have not been recorded throughout the site, the distribution of records indicates usage of the woodlands and taller hedgerows in the northern part of the area. It also appears that barbastelle are likely to commute along a short stretch of the minor watercourse (Watercourse 1) in the northern part of the site (which provides no tree or hedge cover) to reach the woodland blocks; The ‘green lane’ through the centre of the Development Site is clearly an important commuting (and possibly foraging) route for this species based on the number of registrations in this location and because barbastelle were often recorded soon after sunset, when most bat species commute to favoured foraging areas; Similarly, the number of records on Ben Hole Lane spread throughout the survey period suggests this is also an important feature for barbastelle; The records of barbastelle south and west of Pixies’ Mound in combination with the other records within the site and from the driven transects suggests that barbastelle may be crossing the existing power station access road and travelling east. It is therefore possible that barbastelle are foraging in the mosaic of habitats south of the existing power stations or commuting to foraging areas further east; and The early evening and late morning records are evidence that barbastelle may utilise the site throughout the night. 18.5.129 In addition to the 2009 records, the desk study revealed that lesser horseshoe bats had previously been recorded within the site, although there were no previous records of greater horseshoe bats. The occurrence of both species is no more than occasional and appears to be largely restricted to the ‘green lane’. 18.5.130 Due to the derelict condition of the agricultural buildings within the Development Site and their fairly exposed locations along the coast, they are all considered to have low potential as breeding sites for bats, and are unlikely to support large maternity colonies of any species. However, there are cracks within the stone-work of every building that could be used for roosting by a small number of non-breeding bats (such as males or pre-pubescent females) and the surveys have shown that three of the four buildings do support very small pipistrelle roosts (likely to comprise one or two bats only). Despite the lack of evidence of roosting bats in the fourth building, it is similar to the others and it is therefore highly likely that it will also be used by small numbers of roosting bats. The surveys indicated that the only bats roosting in the buildings were pipistrelle species, but there is also potential for Myotis sp. and long-eared bats to use them. 18.5.131 The cracks identified in the stone-work of the buildings could also lead to cavities within the walls, which could be sufficiently insulated (due to the thickness) to allow hibernation. It is unlikely that a large hibernation roost would occur, but small numbers of pipistrelles, Myotis sp. and long-eared bats could use the buildings during the winter, particularly if suitable hibernation sites are infrequent in the surrounding area. 18.5.132 One confirmed tree roost has been recorded within Development Site, located within a field maple at the edge of Woodland C. The roost comprises a 25cm cavity in a branch 7m above the ground, which contained a small number of droppings. Due to the location of the droppings,
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 57 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology these could only be identified through an endoscope and are considered likely to belong to Myotis sp. but the characteristics visible suggest they could also belong to barbastelle. As droppings can decay quickly in damp locations (such as tree roosts) it is considered this roost was occupied in 2009. However, due to the small size of the cavity it is likely to be used as an occasional roost only (not a maternity roost) by a small number of bats in summer and possibly in warmer weather during the winter. 18.5.133 In additional to this tree, eleven other trees are considered to support features with medium to high potential to support bat roosts (although no evidence was found during the survey). 18.5.134 Survey results from work undertaken in 2007-2009 are shown on Figures 18.32 to 18.34 with more detailed results from the 2009 work in Appendix 18e. h) Water Vole i) Desk Study Information 18.5.135 Previous evidence of water vole within or adjacent to the Development Site boundary is limited. The species was recorded during ad hoc surveys by the BE site warden in 1995, 2006 and 2008. These records relate to Pixie’s Pond, the substantial rhyne that marks part of the south site boundary and the rhyne to the east of the built plant. All were of individual field signs (rather than established populations); 18.5.136 SERC also hold records of water vole within Branland Copse to the north of Pixie’s Pond (from winter 1995/1996), which seem to relate to a largely defunct pond (now no more than a seasonal depression). SERC data also suggests that water vole was recorded on rhynes to the east of the existing power station in 1995; 18.5.137 The Somerset Levels, which are connected to the Development Site via rhynes and the River Parrett have been recognised by the UK BAP Water Vole Steering Group as a national key site for water vole, which is a priority species in the West Somerset BAP. This is largely due to the significant amount of reed bed present within the Levels, a habitat which is known to support high numbers of water vole (which can persist in this habitat, despite the occurrence of mink [Strachan & Moorhouse, 2006] (Ref. 18.18). The Somerset Levels and Moors Natural Area (English Nature, 1997) covers an area that extends to Wick Moor. However the areas of the Somerset Levels that are of greatest conservation importance (the areas that have been subject to designation as a Ramsar Site, SPA and/or SSSI) lie approximately 16km to the east of the site. ii) Survey Data 18.5.138 A detailed description of the physical and vegetative characteristics of each watercourse identified in Figure 18.11, and still water-bodies considered is provided below, and also detailed in Appendix 18f:
Watercourse 1, which issues at ST197456 and reaches the shore at ST202461, was initially surveyed in August 2007, with further surveys conducted in September 2008 and May 2009. No evidence of water vole was recorded on this watercourse during the surveys in 2007, 2008 or 2009 (a couple of mammal holes were noted in 2009 but no diagnostic signs of water vole). Given the lack of connection to other water features, colonisation appears unlikely, and the habitat is clearly sub-optimal for the species. Pixie’s Pond (Water body 2 on Figure 18.11), had no evidence of water vole presence during the surveys in 2007 or 2009. Watercourse 3 (North Moor Ditch) was surveyed in both 2007 and 2009. Mammal runs found on the banks of the ditch in 2007 and 2009 were considered to have been created by rabbits and/or badgers as they were too large for water vole. No evidence of water vole or was recorded on this watercourse during the surveys.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology
Watercourse 4 (Holford Stream) varies in depth between 0.2 and 1m, and the western section is generally dry, and only holds water after heavy and prolonged rain. The remainder of the watercourse is subject to grazing and poaching by cattle. No evidence of water vole was recorded from this watercourse during the surveys in 2009. Watercourse 5 (Bum & Bayley’s Brook) was surveyed where it is adjacent to the southern site boundary. No evidence of water vole was recorded during the survey undertaken in 2009. Small mammal latrines were found but the droppings were too small to be water vole. Water body 6 is a large pond. No evidence of water vole was recorded on the pond during the surveys during 2009. Water body 7 is approximately 20m x 8m in size and is located within a hedgerow boundary adjacent to an arable field. The pond is heavily scrub encroached (approximately 90% shaded) and is dry during the summer months. No evidence of water vole was recorded from the water body during surveys in 2008 and 2009. Watercourse 8 comprises a ditch which does not hold water with regularity. A survey in autumn 2008 found the ditch to hold very limited water, and it was completely dry in May 2009. No evidence of water vole was recorded during the surveys in 2008 or 2009. 18.5.139 The three watercourses within the Development Site boundary (Watercourses 1, 4 and 8) and Water bodies 2 and 7 are generally shallow (or dry) and often shaded or disturbed by stock. In most locations they also lack wide densely vegetated banks, whilst the watercourses are narrow in width. Whilst these habitat features do not preclude the presence of water vole, deep, quite wide watercourses (at least 1m) and slow flowing water which is not shaded are typical features of habitats favoured by this species in lowland Britain. Wide vegetated margins and in-channel vegetation are also important for water vole, providing both cover and food (Strachan & Moorhouse, 2006) (Ref. 18.18). Therefore, the water features within the site do not provide optimum habitat, which reduces the potential for water vole to occur. 18.5.140 The pond and watercourses outside the site (i.e. Watercourses 3 and 5 and Waterbody 6) have higher potential to be used by water vole as they are slow flowing and often less shaded, with some sections of species-rich bank (which provide potential foraging habitat). The watercourses adjacent to the site are also better connected to the wider ditch and watercourse network to the east and south, but provide limited opportunity for movement to the west of the site (i.e. Bum Brook does not connect directly to watercourses to the west). 18.5.141 Notwithstanding the survey results, the desk study records clearly indicate that water vole are occasionally present at Pixie’s Pond and on water features adjacent to and within 3km of the Development Site boundary. The likely explanations for the occasional presence of water vole are that the watercourses:
Have not been fully colonised by water vole from the River Parrett catchment and the occasional records relate to dispersing pioneer individuals; and/or They have been previously colonised by water vole, but that the population is now absent (e.g. through mink predation), as small populations of water vole are vulnerable to extinction (Strachan & Moorhouse, 2006) (Ref. 18.18). 18.5.142 As the water features adjacent to the site are hydrologically connected to further areas of suitable water vole habitat to the east and south (e.g. the River Parrett) and provide reasonably suitable habitat themselves, there is some potential for water vole be present or colonise these features in the future. However, given the short lengths of the watercourses within the site, their relatively isolated position from the many rhynes to the east of the site and the lack of further connectivity to the west, it is considered that there is only limited potential for water vole to be present or colonise Watercourses 1, 4 and 8 and Waterbody 7, even if water vole are present nearby.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 59 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.143 Given, on the basis of the survey information, that water vole are either not present within the Development Site or that the potential for its colonisation is extremely limited it is concluded that further assessment of the potential effects of the development on this species is not necessary and further consideration is not provided in the rest of the EnvApp. i) Otter i) Desk Study Information 18.5.144 A fresh otter spraint on the sluice on the rhyne to the east of the operational plant was recovered on 31st August 2009. Previous to this record, otter signs had been recorded to the east of the Development Site on the rhynes of Wick Moor and around a water-body to the east of the sewage works within the site boundary, predominantly in the winter months. Footprints have been the most common field sign noted, although spraints were found in 1999 and 2004. SERC holds records of otter on Wick Moor to the east of the existing power station from 1978 and 1999 (ST217458). Two records (from 1978 and 1984) are also located to the south of the power station, by Wick Moor Drove (ST208448). 18.5.145 The 50km grid square in which the Development Site is located was not surveyed as part of the Environment Agency’s Fourth Otter Survey (2007) (Ref. 18.9). However, results from the adjacent grid squares show many sites have continued to support otter since the last survey and that new sites with confirmed otter presence have been found. Since the last survey in 1991-1994 there has been a 121% increase in the number of sites used by otter in the Wessex region. Surveys undertaken by the Somerset Otter Group suggest that within the 50km grid square the local population is strong and that the Wessex region is a link between the re- colonised Thames Catchment and densely populated areas in Cornwall and Devon. 18.5.146 More detailed information provided directly by the Somerset Otter Group regarding the otter population in the wider area, indicates that the local population may be at carrying capacity, as otters are known to occur on all the major watercourses (including the River Parrett and its catchments to the east of the SSA and on smaller catchment watercourses to the west such as those that discharge at Kilve and Willton). It is therefore considered likely that local otters use all of the available watercourses. ii) EIA Survey Data 18.5.147 A detailed description of the physical and vegetative characteristics of each watercourse and still water-body for which survey information is available is provided below and in Appendix 18f. 18.5.148 Within and adjacent to the site, watercourses/water-bodies 1-3, 4-6 and 7 & 8 (see Figure 18.11) were surveyed in 2007 and 2009; 2009; and 2008 and 2009 respectively. Signs of otter presence were limited:
In 2009 an old otter spraint was found on a rock next to a field gate (prior to a culverted section of the watercourse) at grid reference ST215455. This is adjacent to a small (and predominantly dry) drain that flows into Watercourse 3; Evidence of use by otter was found in three locations along a 200m stretch (approximate central grid reference ST203445) of Watercourse 5 in 2009. This evidence comprised two regularly used sprainting sites on prominent rocks (in both locations there was one recent spraint and a number of older spraints present) and a small, old spraint on a rock at the western edge of the reinforced bank. 18.5.149 A number of locations outside of the Development Site were selected for survey in order to provide further contextual information. These locations, the reasons for their selection and the results of surveys from each are presented in Table 18.5.7 below (and are shown on Figure 18.12);
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Table 18.5.7: Otter Survey Locations Outside of the Development Site and Results
Location Location Name Grid Reason for Selection, Description and Results Number Reference
1 North of Stolford ST2245 Confluence of the larger East and West Brooks, which link to Bum Brook/Bayley’s Brook. The watercourses in this area have a steady flow and are located in steep sided ditches. Stock poaching occurs in some locations. The banks are generally un-mown and species-diverse. The water levels are controlled by sluice gates and several stone bridges cross the ditches. Probable otter spraint present at the Environment Agency’s Great Arch compound, ST228459 (access to confirm was not available).No other signs.
2 South Brook, ST255435 Larger watercourse flowing west to east that Combwich connects smaller watercourses closer to the Development Site (around Stolford) to the River Parrett. The South Brook is a fairly fast flowing, deep watercourse with steep tall banks (~1m tall). The banks are un-mown and support a diverse range of tall grasses and herbs. No evidence found.
3 Bum Brook at ST182443 Otter known to occur on the Bum Brook. Site Honibere Wood selected to investigate whether otter may travel up Brook and cross to the Kilve Brook catchment. The Bum Brook is fast flowing in this location and ~60cm in width. At the survey location the Brook flows underneath a stone bridge and is joined by a south-north drain flowing along the edge of Honibere Wood. Stones are present within the channel. Probable otter footprints were observed in soft mud underneath the stone bridge (restricted access prevented confirmation). No other signs.
4 Stogursey Brook ST188208 The Stogursey Brook flows south to north and at Stogursey connects to the Bum Brook just east of the Lane Development Site. Survey location selected to investigate movement of otter from the south. The Stogursey Brook is fast flowing and approximately 1m wide. The banks are shallow in this location and the base of the watercourse is a mixture of silt and stone. The watercourse
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Location Location Name Grid Reason for Selection, Description and Results Number Reference
has some rough bank side vegetation and overhanging trees, although the north bank is grazed. Otter spraint present on large rock ~5m east of the road bridge at the confluence of the Stogursey Brook and minor stream. Several spraints of varying age were present. No other signs.
5 Kilve Brook ST144443 Potentially suitable (and accessible) location to discharge confirm otters present on Kilve catchment to west of site. At the survey location the Kilve Brook is fast flowing over a rocky substrate, but is heavily shaded by the adjacent trees and scrub. It is approximately 2m wide and discharges into a large pool just above the high tide mark. A well used car park is present at this location and the Brook is quite disturbed here. No evidence found
6 Bayley’s Brook ST194430 Previous records from Shurton (to the north). Site selected to investigate otter usage of the Brook (which joins with Bum Brook) to the south of the site. No access was possible. Vegetation obscured the view of the Brook in this location.
7 Newnham Bridge ST207443 Another sampling point of the Stogursey Brook to investigate if otter are travelling north-south to and from the site via this watercourse. The watercourse here has a steady flow over a mixture of silt and rocks. The banks are fairly steep (~60cm tall) and well vegetated with rough grasses and herbs. Scattered rocks protrude from the water surface. Upstream of the bridge the watercourse is shaded adjacent to a track and garden. No evidence found.
iii) Habitat Suitability for Otter 18.5.150 No evidence of otter presence was found within the Development Site during any of the survey work conducted between 2007 and 2009. During the 2009 surveys, however, otter activity was recorded on the Bum Brook/Bayley’s Brook adjacent to the southern boundary of the Development Site and also on a drain to the south-east of the Development Site. Otter
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology presence was also recorded on watercourses to the west, south and east that are hydrologically linked to watercourses adjacent to the Development Site. The locations of otter signs are shown on Figure 18.35. 18.5.151 Whilst none of the water features surveyed adjacent to the site and in the wider area are particularly large (i.e. could be classed as rivers), all are well connected to further watercourses and areas of wetland habitat. Therefore, they provide ideal commuting corridors. In addition, the faster flowing and larger streams surveyed (e.g. Bum Brook and Stogursey Brook) are likely to support good populations of fish and are therefore likely to be important for foraging as well as commuting. 18.5.152 Although otters will readily travel over land between catchments, the watercourses within the Development Site are poorly connected to catchments to the west. Therefore, it is unlikely an otter would use Watercourses 1, 4 or 8 to travel east to west when the Bum Brook provides a greater length of watercourse (which is also well vegetated) and therefore reduces the distance of terrestrial travel to reach the Lilstock/Kilve watercourses to the west. In addition, the smaller partly seasonal water features within the site are unlikely to provide enough resources (such as fish and amphibians) to be used extensively throughout the year. 18.5.153 All the water features surveyed are predominantly undisturbed by human activity and have areas of dense vegetation adjacent which could be used for couches (generally temporary, daytime resting places). Given the limited foraging resources associated within the water features within the Development Site boundary, however, these are unlikely to be favoured locations for natal holt sites, which tend to be located in close proximity to the most productive areas of the home range. 18.5.154 It is therefore concluded that the water features within the Development Site offer limited commuting, foraging or resting/breeding opportunities for otter due to their relatively isolated location (from other water-bodies) and small size, and there is low potential for them to be utilised frequently by otter. The watercourses adjacent to the site (and in the wider area) provide better habitat for otter and are clearly used preferentially (and probably more regularly given the resources available) by otter to those within the site. j) Dormouse i) Desk Study Information 18.5.155 Prior to this EIA, no formal dormouse surveys had been undertaken on the Development site, or in the immediate surrounding area. 18.5.156 The nearest dormouse record is from approximately 6.5km to the south-west at Holford on the edge of the Quantock Hills (1994). There are three further dormouse records from the Quantock Hills with further records on Exmoor to the west and Taunton to the south (National Biodiversity Network website). 18.5.157 Dormouse is listed as a priority species on the UK BAP and is considered to be a notable species in West Somerset (West Somerset LBAP). ii) Survey Data 18.5.158 The surveys conducted between June and November 2007 recorded no signs of dormouse activity within the Built Development Area West. Further nut searches were conducted in November 2008 and found no signs of dormouse feeding activity. 18.5.159 No dormice or signs of dormouse presence such as nests or feeding remains were found in any of the 270 tubes deployed in 2009. A detailed report on dormouse survey and results is found in Appendix 18g.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 63 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.5.160 On the basis of the survey data to date and the suitability of habitat, there is very limited likelihood of dormouse being present within the Development Site, therefore no further assessment work with respect to this species is considered necessary. k) Badgers i) Desk Study Information 18.5.161 Badgers are numerous in West Somerset, with information provided from a number of sources relating to the Development Site. Records suggested that badgers occur throughout the search area. ii) EIA Survey Data 18.5.162 The 2009 badger survey work provides the most relevant and up to date record of badger activity in the area, and the results are summarised as follows: 18.5.163 Sixty-five setts were identified within the 2009 badger survey area including 14 main setts (i.e. 14 social groups), 12 annexe setts, two subsidiary setts and 37 outlying setts. Of these, twenty- eight were located within the Development Site boundary. These included six main setts, five annexe setts and 18 outlying setts. iii) Assessment Situation for Badger 18.5.164 As opposed to other protected species considered within this assessment, badgers are protected on welfare grounds rather than due to their biodiversity value. This prevents intentional killing and other forms of persecution. Badgers are common throughout much of the UK, particularly in lowland areas, and continue to expand their range into parts of Eastern England where they were formerly much reduced or locally extirpated due to persecution. As such, they do not feature on the UK BAP or on any other generally accepted schedule of species of conservation concern or importance. 18.5.165 It follows that badger is not considered to be an ecologically valued receptor, and further assessment on effect on the species is not required to inform this assessment. However, given the protected status that badgers are afforded they are a material consideration of the planning process, and a separate consenting process involving Natural England is being conducted. The outputs of this have been a detailed badger mitigation report that aims to ensure that badger welfare is not affected by the proposed Hinkley C development. 18.5.166 The results of the 2009 survey, the bait marking study and mitigation report have been provided to Natural England. As the information contained in the reports could potentially be used to harm the welfare of this species it cannot be widely circulated and is not provided as an integral part of this ES. l) Great Crested Newt i) Desk Study Information 18.5.167 A summary of great crested newt records identified during the desk study is provided in Table 18.5.8 (information was provided by SERC and Somerset County Council):
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Table 18.5.8: Great Crested Newt Records from within and in Close Proximity to the Development Site
Date (s) Grid Description of Location Distance from Reference Development Site
1994, 1995, ST207458 The north-west corner of Branland copse Within 1996 and the edge of car park (may relate to a largely defunct pond in the wood)
1995 ST210458 Pixie’s Pond Within
1996 ST232453 Fields to the east of Stolford 1.5km east
18.5.168 Pixie’s Pond was created in 1992-1993 and supported all three British species of newt; smooth, palmate and great crested shortly thereafter (Burrell, 2005) (Ref. 18.33). When the pond was first created it contained abundant stonewort, which is an ideal egg laying plant for newts. However, the pond has been steadily colonised by common reed, reducing the amount of open water area and the amount of stonewort present, although suitable egg-laying plants (such as water mint) are plentiful. Sticklebacks (fish) which prey on the eggs and larvae of newts, were also introduced to the pond after it was created. Since 1993 the number of newts recorded within the pond has declined, with only smooth newts recorded since 1995. 18.5.169 Surveys of Pixie’s Pond conducted in 2006 for Magnox Electric Ltd did not record great crested newts. 18.5.170 In the wider area, there are populations of great crested newt known to occur approximately 1.5km to the east of Hinkley B, in the Stolford area. Given the network of rhynes within the moors between Stolford and Hinkley, it is possible great crested newts have previously colonised the ponds in the vicinity of Hinkley Point C via these drainage channels. However, it is thought that newt eggs can also be transferred between ponds on the feet of wildfowl and therefore it is possible the great crested newts that were present could have originated from much further away. m) Survey Data 18.5.171 A total of 12 ponds were identified that were within 500m of the Development Site boundary (See Appendix 18h for further details). These were subject to further screening to ascertain whether they were potentially suitable to support great crested newts. 18.5.172 The Habitat Suitability Index (HSI) score for each pond subject to screening in 2009 is shown in Table 18.5.9. This table also provides a brief description of each pond, highlights whether the ponds were then screened into the surveys or not and outlines the reasoning behind this. 18.5.173 The categorisation of HSI scores are as follows:
<0.5 Poor; 0.5-0.59 Below average; 0.6-0.69 Average; 0.7-0.79 Good; and >0.8 Excellent. 18.5.174 Oldham et al (2000) (Ref. 18.27) state that the lowest HSI score obtained from a pond known to support breeding great crested newts is 0.43.
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Table 18.5.9: Pond Descriptions and Results of Screening
Pond Description Distance HSI Score Screening Decision Number from the Development Site
1 (Pixie’s Common reed covers Within the site 0.42 Screened in. This pond Pond) approximately 30 % of boundary (poor) has supported great the water surface with crested newt in the past blanket weed (last recorded 1993) and (Spirogyra adnate) provides some limited present in the areas of suitable habitat remaining area of open with open water and water. Bulrush (Typha suitable egg laying latifolia), marsh- media. No great crested marigold (Caltha newts were recorded in palustris), the presence/ absence meadowsweet survey in 2007. HSI (Filipendula ulmaria) score reflects the current and water mint (Mentha deteriorated state of the aquatica) also occur pond. around the margins of the pond. The pond is relatively deep (over 50cm) and approximately 10m x10m in size.
2 A relatively large water Within the site 0.38 Screened in. Surveys body (~15m by 15m), boundary (poor) were conducted at the dominated by common pond in 2006 (for the reed around the edge of Hinkley A the pond with a small decommissioning ES) central area of open with no newts of any water. Crack-willow species recorded and (Salix fragilis) trees and the HSI score is poor. blackthorn and bramble However the pond is scrub occur around the within the site and edges. The pond is of located between Pond 1 unknown depth. It is and historic records of frequented by ducks great crested newt and swans. around Stolford.
3 The pond is located Within the site 0.53 Screened in. Although adjacent to a hedgerow boundary (below there is potential for the and at the corner of an average) pond to dry out, this can arable field. The pond favour newts by has a mixture of willow removing the fish and hawthorn growing population, which is in the centre. There are reflected in the HSI very few aquatic or score. Also, it lies within
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Pond Description Distance HSI Score Screening Decision Number from the Development Site
marginal broad-leaved the site and therefore plants and although affects on the pond as a there are areas of open result of the water the pond has development could be 90% shading from the greater. surrounding scrub and hedgerows. The pond is approximately 20m by 8m in size.
4 A small (~10m by 4m), 80m to the east 0.54 Screened in. Although quite shallow water (below there is potential for the body (between 0.5 and average) pond to dry out, this can 1m), the surface of favour newts by which is 100% covered removing the fish in floating grasses and population which is algae. The pond lies at reflected in the HSI the edge of an arable score. Also, the field with vegetation would approximately 10% provide suitable egg shading, and is laying media. Hedgerow adjacent to a species- connection to poor hedgerow. Development Site boundary.
5 This water body is quite 387m to the 0.4 (poor) Screened out. The pond small (~8m by 4m) and west is likely to remain dry for connected to a drain. the remainder of the The pond was dry. season.
6 A small pond (~10 by 120m to the 0.59 Screened in. The pond is 10m), fairly deep east (below within 500m of the site (approximately 1m), average) boundary and is a with 100% aquatic suitable pond, as vegetation cover and reflected by its HSI 50% macrophyte cover. score, for newts. It The pond is located in supports an abundance the middle of a cattle of egg laying media and field with no shading. is bordered by habitat Ducks observed using which could support the pond. newts in their terrestrial phase. The pond is also located between Pond 1 and historic records of great crested newt around Stolford to the east.
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Pond Description Distance HSI Score Screening Decision Number from the Development Site
7 A fairly large pond (~20 335m to the 0.67 Screened in. The pond is by 20m), possibly an west (average) within 500m of the site old quarry, with 95% boundary and is a duckweed cover and suitable pond, as 10% shading. The pond reflected by its HSI has very steep sides score, for newts It with dense vegetation. supports an abundance of egg laying media and is bordered by habitat which could support newts in their terrestrial phase. The pond is reasonably well connected to the site via intact hedgerows.
8 The pond (~30m by Within the site 0.46 Screened in. Whilst it 10m) is effectively the boundary (poor) appears that vehicles do pooling of a cross the ford/pond, this watercourse at the end is likely to be restricted of a ford and therefore to the occasional likely to be occasionally agricultural vehicle, and disturbed by vehicles. it is a large enough water The base of the pond is body that parts of it are stone, there is 10% left undisturbed by these shading and 10% activities. Although the macrophyte cover. HSI score is low, some residual potential remains for it to support great crested newts.
9 The pond is not Within the site Pond no Screened out. present. A small boundary longer watercourse is present present with no significant pooling.
10 A small (~10m by 4m), 290m to the 0.52 Screened out. The pond but dry pond with east (below is likely to remain dry for approximately 10% average) the remainder of the shading, adjacent to a season. species-poor hedgerow.
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Pond Description Distance HSI Score Screening Decision Number from the Development Site
11 A small field pond, 300m to the 0.4 (poor) Screened in. The pond is approximately 5m by south east within 500m of the site 5m, with poor water boundary and has some quality, 100% shading limited potential to and no macrophytes. support great crested newt should a source population be present in nearby ponds. There is hedgerow connection to site boundary.
12 A private small garden 360m to the 0.57 Screened out. The pond pond, 5m by 5m at the south (below is approximately 450m most, supporting 90% - average) from the site boundary 100% macrophyte and is separated from it cover. by a minor road. The habitat connections between the pond and the site are poor comprising four large arable fields and no substantial field boundaries leading to the site. .
18.5.175 On each survey visit in 2009, dependent on the pond conditions, the most appropriate survey methods were employed, including torchlight surveys, trapping and searches for eggs. Fish were recorded in large numbers in Pond 1 (also in 2007) and Pond 6 and in less abundance in Pond 3. In addition, great diving beetle (Dytiscus marginalis), which predate on the larva and eggs of newts, was recorded in Pond 1. 18.5.176 Ponds 2, 3, 6 and 8 support smooth newt, and Pond 4 supports palmate newt. Pond 1 also supported palmate newts in 2007 but these were not recorded in 2009. No newts were recorded in Pond 11. 18.5.177 No great crested newts were recorded in any of the ponds during the 2009 surveys. The surveys of Pond 1 in 2007 also did not record great crested newts. 18.5.178 Based on the survey effort completed, it is therefore reasonable to conclude that great crested newts do not occur within the water-bodies surveyed. Given this, and the suitability of habitat, no further assessment work with respect to this species is considered necessary. n) Reptiles i) Desk Study Information 18.5.179 SERC provided several records of reptiles in the vicinity of the Development Site.
Grass snake was recorded in Branland Copse, between Branland Copse and the Sewage Treatment Works (STW) and off site at Stolford ~ 1.4km east in 1995 and 1996; and
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Slow worm was recorded near Stolford in 1996 ~1.2km east) and to the south around Shurton in 1995 ~ 300m to the south). 18.5.180 Reptile surveys were not undertaken in relation to the West Hinkley Wind Farm EIA as it was considered that the extent of suitable habitat for reptiles was limited. 18.5.181 The ecology surveys in relation to the decommissioning of Hinkley Point A did not include reptile surveys as the habitats affected by the works (predominantly hard standing) were not considered suitable for reptiles. 18.5.182 No formal reptile surveys have previously been conducted within the former BE landholding, although it is noted (in British Energy 2006) that the last sighting of grass snake was made in 1999. A common lizard was recorded to the east of the built plant near the sea defence in 2007 (BE Warden pers. comm.). A mature grass snake was seen close to Pixie’s Pond in 2007; slow- worm are occasionally recorded, most regularly in the area directly south of Hinkley B. ii) EIA Survey Data 18.5.183 The presence of two reptile species (slow-worm and grass snake) was confirmed from the surveys undertaken within the Development Site. 18.5.184 Table 18.5.10 below summarises the maximum counts of adults for each species, within each area (i.e. the highest number of adults recorded on a single survey visit). Juveniles were also detected during these surveys but are not included within this population class assessment, as per Froglife (1999) (Ref. 18.29) guidelines. Table 18.5.10: Maximum Counts of Adults of Each Species in all Compartments
Species Common lizard Slow-worm Grass snake
Area 1 0 0 0
Area 2 0 3 0
Area 3 0 9 4
Area 4 0 1* 0
*This individual was recorded in the part of Area 4 that overlaps with Area 2 18.5.185 Reptile use of the sampled areas is summarised as follows:
In Area 1 no reptiles were observed underneath or on top of any refugia placed. Common toads were found using the refugia on two occasions; In Area 2 a maximum count of three slow-worms was recorded in 2008, which equates to a density of 0.2 slow-worm per hectare. These were all recorded along the south facing side of the hedge adjacent to the track which bisects the site from east to west; In Area 3 a maximum adult count of nine slow-worms and four grass snakes were recorded, which equates to a density of 0.9 slow-worm and 0.4 grass snake per hectare. Pixie’s Pond and the western edge of Branland Copse (i.e. adjacent to the road) appeared to be favoured by grass snake. The teasel field at the centre of Area 3 (i.e. between the communication masts), which includes small areas of poorly drained and wet grassland, also supports grass snake and slow-worm. In both these areas large numbers of juveniles were recorded suggesting that both species are successfully breeding. There were 2 inconclusive sightings of common lizard in the Pixie’s Mound field. This may indicate a very small population of this species is present, but this was not confirmed; and
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In Area 4 a maximum count of one slow-worm was recorded in 2009. This was in the same location that slow-worm was found in 2008 (i.e. in Area 2, along the south facing side of the hedge adjacent to the track which bisects the site from east to west). As the hedge does not appear to have been regularly managed it is unlikely to have changed significantly since 2008, and remains just as suitable to reptiles, and which is reflected in the similarities between the two surveys results. No other reptiles were recorded in Area 4. 18.5.186 Based on Froglife (1999) (Ref. 18.29) Guidelines, Area 3 supports a ‘good’ population of slow- worm and a ‘low’ population of grass snake. Areas 2 and 4 indicatively support a ‘low’ population of slow-worm. Based on the data collected, the Development Site does not qualify as a Key Reptile Site (as common lizard is not present). Reptiles are largely concentrated in the mosaic of habitats to the south of the existing power station (Area 3), with smaller numbers along woodland edges and hedgerows in the overlap between Areas 2 and 4. Area 3 supports a mosaic of rough grassland, scrub, wetland areas, and woodland, which is currently ideal for foraging, basking and hibernating reptiles. This area is likely to provide a source population from which individual reptiles can disperse into smaller areas of favourable habitat such as hedgerows and rough grassland located in other parts of the Development Site and off-site. Other areas of the site contain some habitat with potential to support reptiles, but this is fragmented, and much of the land area is subject to intensive farming and is unsuitable. 18.5.187 The conditions in which surveys were conducted, and a full account of reptiles recorded is included in the detailed report on reptiles found in Appendix 18i. The locations in which reptiles were recorded are shown on Figure 18.36 from the TN. o) Invertebrates i) Desk Study Information 18.5.188 The main source of information is the British Energy Annual Land Management Reviews for the period 1998 to 2008 (Ref. 18.32). Mention of invertebrates in these reports is generally limited to the results of butterfly monitoring (for which a complete set of annual data is available going back into the early 1990s). Moth-recording has been undertaken on a more ad hoc basis and records of other invertebrates are largely incidental with the exception of glow-worm for which some monitoring has taken place. A summary of the more notable records is as follows:
Glow-worms (Lampyris noctiluca) occur in scrub between Pixie’s Mound and the sub- stations. Glow-worm is a county or local BAP species in many English counties or vice- counties, but not in Somerset; Chalkhill blue (Polyommatus coridon), was recorded in 1999, but does not occur annually; Good populations of marbled white (Melanargia galathea) are a feature of the semi-natural grassland habitats; Five UK BAP butterfly species: small heath (Coenonympha pamphilus), wall brown (Lasiommata megera), grayling (Hipparchia semele), dingy skipper (Erynnis tages) and grizzled skipper (Pyrgus malvae)); and three Local BAP species (wall brown, dingy skipper and grizzled skipper) have been recorded; The Nationally Scarce beetle platyrhinus resinus has been recorded from Branland Copse. 18.5.189 SERC data lists ten UK BAP moths recorded from Hinkley/Hinkley Point. A further five UK BAP moths are listed within the Land Management Review Annual Reports. 18.5.190 The wider data gathering exercise noted that a UK BAP click beetle Synaptus filiformis is confined in Britain to a short section of the River Parrett near Bridgwater, albeit in the eastern part of the town (Duff 1993) (Ref. 18.35) and therefore several miles from Hinkley Point. 18.5.191 There have also been several aquatic invertebrate surveys previously conducted in the area: one the result of a single day of survey on Wick Moor (Foster, 1986) (Ref. 18.36); a far more
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 71 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology detailed survey of the whole Steart Peninsula (Drake, 2003) (Ref. 18.37), with a further aquatic survey (and butterfly) survey undertaken in 1985 on behalf of the Institute of Terrestrial Ecology [ITE] (Daniels, 1986) (Ref. 18.38).
The former survey covered six sample sites and the author recorded one Red Data Book water beetle (Haliplus mucronatus) and three Nationally Scarce water beetle species. Two species mentioned as Notable (Coccidula rufa and Oplodonta viridula) by Foster (ibid) have since been downgraded in status; Drake (2003) (Ref. 18.37)sampled ten sites on Wick Moor (sample sites 91-100) and around Stolford with another 90 spread out further east as far as Steart. From the ten sample sites, Drake (ibid) recorded one RDB2 soldierfly (Odontomyia ornata) and eleven Nationally Scarce invertebrate species (although Helochares lividus has recently been downgraded from Notable); and The ITE aquatic invertebrate survey involved taking samples from ten sites on one day (20 June 1985). This survey appears to be the most limited of the three: it recorded 18 taxa in comparison with 65 taxa recorded in the equivalent survey in 1985. The 1985 survey also appears to result in a number of erroneous records most notably the whirlpool ram's-horn snail (Anisus vorticulatus) which is a rare species mainly known from East Anglia and a few sites in south-east England. The doubtful record of yellow-veined darter (Sympetrum flaveolum) is also likely to be incorrect, since it appears to be based on the nymphal stage (which had not been described at the time of the record), and the species has only regularly started breeding in Britain in recent years. The record of small red-eyed damselfly (Ceriagrion tenellum) may also be questionable since this species is associated with bog pools and there are no records for the North Somerset coast (Merritt et al 1996) . ii) EIA Survey Data 18.5.192 The initial site walkover in 2008 (which was confined to the Built Development Area West) concluded that the most valuable habitat was likely to be Whitewall Brake (Woodland D – see Figure 18.19), due to its semi-natural characteristics, structure and the maturity of some of the oaks. The Nationally Scarce bombardier beetle Brachinus crepitans was found under a reptile mat located within the coastal strip. 18.5.193 Material from major species groups (Malacostraca, Ephemeroptera, Trichoptera, Plecoptera, Mollusca, Odonata and adult Coleoptera) collected during the kick sampling and sweep netting exercise in September 2008 were identified to species level to characterise the invertebrate community and to identify the presence of rare species. A summary of findings is as follows:
the communities largely consisted of common and widespread species of English watercourses with no rare species identified; invertebrate diversity was low at all sample sites; invertebrate abundance was low at five sites and moderate at three; and invertebrate communities reflect slightly acidic to circum-neutral, eutrophic conditions with high levels of organic enrichment. 18.5.194 In 2009, a total of 152 taxa were recorded during the aquatic invertebrate surveys. Three Nationally Scarce species were recorded, namely the hairy dragonfly (Brachytron pratense), the diving water beetle (Agabus uliginosus) and the reed beetle (Donacia clavipes). The anthomzid fly (Anagnota bicolour), caught in one of the pond net samples, is also Nationally Scarce. 18.5.195 Species richness and diversity was generally low in the streams within the Development Site, confirming the results of the surveys of September 2008. Holford Stream was richer than the other watercourses sampled, being faunistically similar to the Wick Moor rhyne. Bum Brook supported mostly common and widespread running-water taxa in the upstream sample, with taxa more characteristic of slow or still water in the downstream sample. The sampled rhyne on
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18.6 Valuation of Ecological Receptors
a) Introduction 18.6.1 As described previously in the introductory sections to the EnvApp, the determination of the value of the environmental parameters that may be affected by the proposed development is a critical step in the assessment of impact significance. Table 18.6.1 provides a summary of the criteria that are used for classifying value with respect to ecological receptors. For the purposes of assessment each receptor included in the scope of the EIA, has to be attributed a value through comparison with the adopted criteria. This has been undertaken for all of the ecological interests described above and the outcomes are detailed in the following section. b) Valuation Process 18.6.2 Table 18.6.1 lists each ecological receptor (habitats and species respectively), and attributes a value to the receptor as defined in Section 4 on Methodology. 18.6.3 In determining which value criteria to which each receptor can be attributed to, consideration has been given to whether the receptor forms part of the interest of or falls within a designated nature conservation site (e.g. SPA, or CWS). A direct value to the designated site itself has not been applied (i.e. a designated SPA or SAC is an internationally recognised site and therefore its value could be directly attributed as high (international)). This is because direct valuation of what is effectively a legislative/policy boundary/area may not, through assessment, represent the ecological significance of an effect. In this instance, assessment is better undertaken with reference to the actual ecological receptors themselves (i.e. the habitats or species that may be present with the designated site) and then for qualitative assessment to be applied in order to reflect the importance of the designation in which these receptors may occur. It should be noted that for ecological interests located within or forming part of the designated SPA, SAC and Ramsar sites and which may potentially be affected by the Hinkley Point C development, that Regulation 48 of the Habitats Regulations may apply, and appropriate assessment may be required. 18.6.4 There is an interaction expected between these interests and the operation of the cooling water system of Hinkley Point C. For an initial consideration of these matters please refer to Marine Ecology Volume 2, Chapter 19.
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Table 18.6.1: Summary Evaluation of Habitat Receptors
Receptor Applicable Policy Implications Value Rationale Legislation
Lowland calcareous N/A UK BAP Priority Habitat Medium (County) The extent of grassland within the SSA boundary is relatively grassland/Lowland limited, but an NVC survey has confirmed the grassland Section 41 NERC Act meadows within the CWS (habitats of principal present falls under the categories of calcareous importance for biodiversity grassland/lowland meadow, both UK BAP Priority Habitats. Calcareous grassland is scarce at the county level, and the conservation) various calcareous grassland and meadow compartments within the CWS contain a variety of species that are rare or uncommon at the county level at high or moderate frequency. The grassland is therefore considered the most ecologically valuable habitat within the CWS.
Grassland outwith the N/A N/A Low (Parish)/Negligible The best of the semi-natural grasslands within the southern CWS (within the (less than Parish) part of the SSA are an area that has grown up among a young Development Site) broad-leaved plantation woodland and a field adjoining Watercourse 4 (the Holford Stream). With management, the area within the broad-leaved woodland could develop a calcareous sward that could potentially become of District or County importance. There is no evidence of management to this effect however, and the sward is considered of Parish importance (principally due to the presence of a few scarce species and the relative diversity of the community). The area of grassland adjoining the Holford Stream is of Less than Parish importance due to high levels of nutrient enrichment and low diversity and species interest. There are no other pasture areas within the SSA that attain parish level importance.
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Receptor Applicable Policy Implications Value Rationale Legislation
Woodland and Scrub N/A N/A Low (District/Parish) Parts of the woodland and much of the scrub within the SSA Lowland mixed deciduous form part of the Hinkley County Wildlife Site. Whilst the CWS woodland is covered under as a whole is considered to be County importance, the Section 41 NERC Act woodland blocks within the CWS are of relatively recent plantation origin (similarly to the rest of the woodland blocks (habitats of principal within the SSA) and due to their lack of established importance for biodiversity woodland ground flora and poor structural diversity there are conservation) considered to be of no more than parish value. The scrub within the CWS is relatively diverse, is an important part of the CWS mosaic and is considered to be of district importance.
Hedgerows Hedgerow UK BAP Priority Habitat Low (District) The majority of hedgerows within the SSA are intact, but Regulations 1997 Section 41 NERC Act associated field margin communities, where present, lack (habitats of principal diversity (due to agricultural improvement). 18 hedges importance for biodiversity within the area surveyed were found to support 7 or more woody species, making them important under the Hedgerow conservation) Regulations. A further 20 were also assessed as important under the Hedgerow Regulations. Hedgerows are typical boundary features in West Somerset: due to their local abundance and the lack of diversity in the field margins it has been concluded that hedgerows within the SSA are of district importance. There is a separate row in this table that considers habitat networks.
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Receptor Applicable Policy Implications Value Rationale Legislation
Watercourses N/A N/A Low (Parish) Watercourses within the SSA are partially seasonal, show signs of agricultural improvement (poorly developed riparian and aquatic vegetation, limited freshwater invertebrate diversity, considerable poaching of margins by cattle, encroachment by ruderal vegetation etc), and have no protected species. The Holford Stream feeds into the Bridgwater Bay SSSI and is of some importance in this context (as reducing flows may limit future management options within the SSSI – which is currently relatively dry in winter). This does not raise the ecological interest of the Holford Stream, but potentially increases its ecological importance through its contribution to maintaining the integrity of the SSSI. Watercourses adjacent to the SSA, such as Bum Brook/Bayley’s Brook and the watercourse marking the northern boundary of the Bridgwater Bay SSSI (adjacent to the eastern part of the SSA) are of marginally greater botanical interest.
Ponds N/A UK BAP Priority Habitat Low (Parish)/Negligible The two of the pools within the CWS both have semi-natural aquatic vegetation, (common) amphibian populations and Section 41 NERC Act (Less than Parish) (habitats of principal reasonable invertebrate interest. Whilst these ponds are importance for biodiversity within the CWS and contribute to the integrity of the designated site, they do not meet the priority pond criteria conservation) (developed by Pond Conservation) and are therefore considered to be of Parish importance. The other pond (outside of the CWS) is a heavily shaded and scrub- encroached seasonal water-body with no associated ecological interest. It is considered to be of less than parish importance.
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Receptor Applicable Policy Implications Value Rationale Legislation
Coastal Escarpment N/A N/A Low (Parish) There is a thin strip of semi-natural vegetation running along the coastal escarpment (where the cliff does not drop vertically into the intertidal or has not already been consolidated), mainly comprising scrub. The calcareous grassland patches have been valued under that category. The scrub is discontinuous and is of no more than local importance. There is no strip of semi-natural vegetation between the high water mark and the coastal escarpment
Habitat Networks N/A PPS9 Low (District) The mainly intact hedgerows that are present throughout the SSA provide good linkages to on- and off-site woodland and to the coast. The plant approach road presents a barrier to movement between the SSA and the mosaic of habitats to the south of the built plant, but this effect is likely to be relatively limited for most species. The level of use by bats (including nationally scarce species) and the indicative age of some of the hedgerows suggest that they are an important connective feature for protected species dispersal. The water-courses are of less value than the hedges, and are only likely to complement the hedgerows to a minor degree. Their effectiveness as corridors is limited by their seasonality and lack of connectivity. There is little evidence of use of the watercourses by protected species. Overall the habitat networks on site are considered to be of no more than district value no more than district value.
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Receptor Applicable Policy Implications Value Rationale Legislation
Breeding birds (within WCA UK BAP15/Section 41 NERC Medium (County) The breeding bird community is relatively varied and features SSA) Act one Schedule 1 (WCA) species (Cetti’s warbler), as well as some species that occur in numbers of county importance (lesser whitethroat and nightingale) and species included under Section 41 of the NERC Act. However, these species show a strong bias toward the mosaic of habitats to the south of the built plant. Elsewhere within the survey area the breeding bird community is typical of the farmland habitats present, and is of parish importance only.
Wintering birds (intertidal) EU Birds Directive UK BAP/Section 41 NERC High (International) A number of wintering species forming the cited interest of Act the Severn SPA and Ramsar Site regularly occur within 1km of the SSA. The topography, extent and characteristics of exposed shore and to a lesser extent disturbance result in considerable variation in terms of value of the different compartments of shore surveyed.
Passage birds (intertidal) EU Birds Directive UK BAP/Section 41 NERC High (National) A number of passage species forming the cited interest of Act the Severn Ramsar Site and Bridgwater Bay SSSI regularly occur within 1km of the SSA. The topography, extent and characteristics of exposed shore, and to a lesser extent disturbance, result in considerable variation in terms of value of the different compartments of shore surveyed.
15 Skylark is also listed on the West Somerset BAP.
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Receptor Applicable Policy Implications Value Rationale Legislation
Wintering and passage EU Birds Directive UK BAP/Section 41 NERC Low (District) Very low levels of use of terrestrial habitats (both diurnally birds (terrestrial habitats) Act and nocturnally) were noted by birds forming the cited interest of locally designated sites of biodiversity interest. Numbers of some waterfowl species within the fields occasionally passed the threshold of county importance, and the numbers of some wintering passerines recorded suggest more than parish interest.
Barbastelle Bat WCA. Annex II of UK BAP/Section 41 NERC Medium (County) Regular use of the SSA was noted by barbastelle in July and Habitats Directive Act August, mainly from Anabats, with more sporadic records outside this period. SSA potentially used for both Somerset Priority Species commuting and foraging.
Greater Horseshoe Bat WCA. Annex II of UK BAP/Section 41 NERC Medium (County) Only recorded on four occasions from static Anabats despite Habitats Directive Act relatively intensive survey effort, indicating that the SSA is unlikely to support the species on a regular basis. Somerset Priority Species
Lesser Horseshoe Bat WCA. Annex II of the UK BAP/Section 41 NERC Medium (County) Recorded irregularly: e.g. on 2 dates in July and 3 dates in Habitats Directive Act August from static Anabats. Desk based data indicates Somerset Priority Species several previous records.
Bat Assemblage WCA, Annex II of Some species of bats are Medium (County) The SSA and immediately adjacent areas support three Habitats Directive16 listed as Section 41/UK ephemeral common pipistrelle roosts. These buildings, BAP and West Somerset which are structurally unsound and could not be internally BAP priority species. inspected in detail, also have the potential to support winter roosts and may be used by small numbers of Myotis sp. and long-eared bats. One confirmed tree roost is also present
16 This only applies to 5 UK species: barbastelle, greater and lesser horseshoe bats, Bechstein’s bat and greater mouse-eared bat (the latter is particularly rare). The legislation requires sites to be designated in member states for the protection of these species.
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Receptor Applicable Policy Implications Value Rationale Legislation within the SSA, with eleven other trees supporting features with at least medium potential to support roosting bats. There is regular use of parts of the SSA by two pipistrelle species, (brown) long-eared bat, serotine, noctule and barbastelle. This level of use, combined with less regular commuting through the SSA by Myotis species, greater horseshoe and lesser horseshoe bat indicates that the area is of some importance for bats. There is no exceptional habitat present within the SSA, and there are no known important roosts in close proximity to the SSA. Much of the behaviour, particularly of the rarer species, indicates commuting rather then feeding (few feeding buzzes were recorded). The level and nature of use of the SSA by bats is likely to be typical of lowland Somerset and reflects the high level of survey effort and the unusual amount of baseline data available for the locality. Nevertheless, the professional judgement conclusion that the SSA is of importance at the county level (medium) is considered realistic.
Water vole WCA UKBAP and West Somerset Low (Parish) There is some habitat within and adjacent to the SSA Local BAP priority species. boundary that is potentially suitable for water vole, and the Somerset Priority Species. species has been sporadically recorded, suggesting that in Section 41 NERC Act years when numbers are high there is temporary colonisation. On this basis a value of parish is considered appropriate.
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Receptor Applicable Policy Implications Value Rationale Legislation
Otter WCA, The UK BAP Priority Low (Parish) Otter signs have been recorded in the past, and a spraint Conservation of Species/Section 41 NERC was found on the watercourse that forms part of the Habitats and Species Act. Somerset Priority southern site boundary. This indicates that those Regulations 2010 Species watercourses that are connected into wider freshwater systems are likely to be used for commuting, as are all permanent linked watercourses in the county. There is no habitat likely to support otter for a sustained period within or adjacent to the SSA boundary.
Dormouse WCA, The UK BAP Priority N/A No dormice, or signs of their presence, were recorded during Conservation of Species/Section 41 NERC the considerable survey programme conducted. Habitats and Species Act. Somerset Priority Regulations 2010 Species
Great crested newts WCA, The UK BAP Priority N/A No great crested newts were recorded in any of the ponds Conservation of Species/Section 41 NERC surveyed within or outside the SSA boundary. Habitats and Species Act. Somerset Priority Regulations 2010 Species
Reptiles WCA UK BAP Priority Low (Parish) The SSA supports low populations of both slow-worm and Species/Section 41 NERC grass snake. These are largely confined to the mosaic of Act. Somerset Priority habitats to the south of the built plant. The populations are Species below carrying capacity (due to the fact that the area was formerly more scrub dominated). The SSA does not qualify as a Key Reptile Site under Froglife (1999) (Ref. 18.29) Criteria. Whilst both grass snake and slow-worm are common in Somerset county and West Somerset District, the Stogursey parish is predominantly agricultural and offers more limited suitable reptile habitat. Therefore, the reptile population present is considered to be of parish importance.
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Receptor Applicable Policy Implications Value Rationale Legislation
Invertebrates WCA UK BAP Priority Low (District) The mosaic of habitats to the south of the built plant and the Species/Section 41 NERC coastal grassland to the west of the plant have a relatively Act. Somerset Priority diverse butterfly community (predominantly featuring Species common species), and has been reported to be one of the better and most accessible areas to look at butterflies in the county. Further, a small number of rare terrestrial species including one UK BAP species was recorded. The ditches generally have limited species diversity reflecting the limited aquatic vegetation, shading and agricultural improvement, although the Holford Stream proved to be more similar to the watercourse adjacent to Wick Moor than the others within the SSA. Elsewhere within the SSA the open agricultural habitats are of limited value to invertebrates. Overall, the SSA cannot be regarded as of higher than district value to invertebrates.
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ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology c) Information Gaps 18.6.5 The intensive survey work has covered all of the main ecological interest features scoped into the assessment process. The work has also taken into account views and issues raised during the associated consultation with relevant organisations. As such, it is considered that the information provided covers all of the main interests that could potentially be significantly affected by the proposed development.
18.7 Assessment of Potential Effects during Construction
a) Introduction to Construction Phase Effects 18.7.1 The principal construction phase ecological effects will result from the earthworks and the loss of semi-natural habitats and habitat corridors within the Development Site boundary, and temporary land take plus disturbance and displacement of bird populations within the Severn SPA, Ramsar Site and Bridgewater Bay SSSI. Ge-Mare Farm Fields SSSI is considered too remote from the Development Site to be affected by development, while Blue Anchor to Lilstock Coast SSSI is a solely geological designation. Neither site is afforded further consideration in this assessment. b) Key Activities during the Construction Phase 18.7.2 The existing habitat interests of the Development Site (i.e. the semi-natural grassland within the CWS, woodlands, hedgerows, part of the watercourse system and some of the ponds and intertidal areas used by birds) would be affected by the following components of Hinkley Point C construction phase:
topsoil stripping, storage and earthworks across much of the Development Site; Culverting of Holford Stream; demolition of agricultural buildings within the Development Site; construction of a 760m concrete sea wall in front of the existing cliff line; and construction of the temporary jetty. 18.7.3 Individual animals using these habitats (either as residents or temporarily) would be displaced, disturbed or potentially populations reduced or lost (e.g. some invertebrate populations). The loss of woodland and hedgerows would lead to a reduction in available habitat for badgers and bats and changes to the hydrology of the site could affect the use of some watercourses by species such as water vole and otter. Construction activity associated with the sea wall and the temporary jetty could cause disturbance to waders and wildfowl using adjacent intertidal areas. The consequences of these construction phase effects are further detailed in the following sections c) Approach to Mitigation during Construction 18.7.4 Without any attention to scheme layout and methods of construction a number of potentially significant ecological effects could arise, as potentially the development could have been sited anywhere within the SSA. The following sections detail mitigation which has been incorporated within the development design to avoid and minimise potential ecological effects. For many ecological receptors, this mitigation is considered likely to be fully effective, or is predicted to reduce effects to the point that they will be no greater than of minor adverse significance. 18.7.5 The construction phase environmental measures proposed in the Sections below will be managed as part of a Site wide Environmental Management and Monitoring Plan (EMMP). The EMMP will be produced prior to the start of construction and will provide further detail on the environmental measures proposed and the mechanisms by which these will be implemented. It
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology is anticipated that an ecological clerk of works will be employed to manage and undertake the measures and to ensure the biodiversity information within the EMP is accurate and up-to-date. In conjunction with the EMP, the existing EDF Energy Integrated Land Management Plan (ILMP) will be updated to include the proposed management of retained habitats during the construction phase. d) Habitat Loss i) Grassland 18.7.6 The extent of grassland within the Development Site boundary is relatively limited, but an NVC survey has confirmed that some of the grassland present falls under the categories of calcareous grassland/lowland meadow, which are both UK BAP Priority Habitats. Calcareous grassland is scarce at the County level, and the various calcareous grassland and meadow compartments within the CWS contain a variety of species that are rare or uncommon at the county level at high or moderate frequency. The grassland is therefore considered the most ecologically valuable habitat within the CWS and is of medium (County) importance. Grassland in the remainder of the Development Site (~28.9ha) is of no more than parish value. 18.7.7 If all of the grassland of defined value were to be lost from within the Development Site (i.e. the vast majority of the CWS) this would constitute a permanent and high magnitude effect, leading to an impact of moderate adverse significance. Loss of grassland outside the CWS would be of no more than minor adverse ecological significance; Mitigation 18.7.8 With particular regard to non-statutory sites, it should be noted that the retention of the land to the south of the existing built plant, detailed below, will result in the preservation of approximately 42% of the Hinkley CWS. The grassland habitat that is subject to CWS designation and will be lost includes 2 small areas, totalling 1.5 ha, of calcareous grassland (the coastal strip and a small area on the seaward side of the training building) and a far more substantial area (approximately 22 ha) of pasture (which is gradually becoming more species- rich due to management but which was classified as improved during the Phase 1 Habitat Survey). 18.7.9 The design of the plant will avoid any land take from the mosaic of habitats to the east of Wick Moor Drove, including Branland Copse, the Pixie’s Pond area and the Sewage Works. As such, much of the botanical interest of the Hinkley CWS (and the Development Site as a whole) will be retained, including all reedbed, the majority of the scrub and a large proportion of the more botanically diverse grassland (i.e. the lowland meadow grassland). Refer to Figure 18.1. 18.7.10 To mitigate for the loss of habitat from within the Development Site, it is proposed to create a mosaic of habitats, a relatively high proportion of which will be grassland. To contribute to the recreation of grassland habitats, seed will be collected from existing areas within the CWS over two successive years (2009 and 2010) and will be used to recreate grassland on a suitable receptor site (see Section 18.8.6 on operational mitigation). 18.7.11 Taking into account the fact that the design layout within the Development Site allows for retention of much of the species-rich grassland within the existing CWS it is considered that the overall magnitude of change would be reduced to low and as a consequence the post- mitigation impact rating would be of minor adverse significance.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 85 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology ii) Woodland 18.7.12 Parts of the woodland and much of the scrub within the Development Site form part of the Hinkley CWS. While this designation infers county importance, the surveys undertaken indicate that the woodland that would be lost comprises NVC woodland communities that occur commonly throughout the UK. It is apparent that generally the woodlands are species-poor examples of these community types and none of the woodlands in the Development Site are considered to be ancient (i.e. they were not present prior to 1600AD) and many have only developed over the last 100 years. It is therefore considered that while these woodlands are within the CWS, from an ecological perspective they are of local/parish value. 18.7.13 Outside of the CWS, with the exception of Whitewall Brake (which is of greater age and better structure) other belts of woodland are of relatively recent plantation origin and it is considered that these are of no more than parish value. 18.7.14 The loss of woodland from within the Development Site (including that within the CWS) would constitute a permanent, high magnitude effect on a resource of local/parish value, resulting in a moderate adverse significant effect (prior to mitigation). Mitigation 18.7.15 The majority of woodland will be removed during the winter period. Mitigation during the construction phase will aim at limiting effects on species making use of the woodland, and is discussed in subsequent sections. iii) Hedgerows 18.7.16 The majority of hedgerows within the Development Site are intact, but associated field margin communities, where present, lack diversity (due to agricultural improvement). Seventeen hedges within the area surveyed were found to support seven or more woody species, making them important under the Hedgerow Regulations. Hedgerows are typical boundary features in West Somerset. Because of their local abundance and the lack of diversity in the field margins, it has been concluded that hedgerows within the site are of local/parish importance. The complete removal of the hedgerows from within the Development Site would constitute a high magnitude effect, leading to a moderate adverse impact prior to mitigation. Mitigation 18.7.17 Hedgerows running east-west across the centre of the Development Site and north-south along the western site will be retained to enable continued movement of bats, invertebrates and birds across the development area. These are established hedgerows, being (largely) located along the green lane17 and a bridleway (Benhole Lane) respectively; both are well connected to other hedgerows and woodland in the wider landscape and are important in terms of the Hedgerow Regulations due to the number of woody species they support. A strip of land to the east of Benhole Lane (within the site development boundary) will also be retained during construction to buffer Benhole Lane from construction disturbance. 18.7.18 Additional planting will be established, using mature specimens, broadly along the Bum Brook forming a further east-west corridor available for wildlife movement. The eastern section of the green lane will be removed during construction to accommodate the access road and substation. However, habitat connectivity will be maintained via new hedgerow planting linking the green lane to retained hedgerows along the edge of the site development boundary.
17 The majority of the lane running east-west across the central part of the site will be retained (approximately 2/3 of the western part of the track), with additional linking hedgerows retained and new hedgerow planting undertaken during parts of the construction phase to ensure a continual link to Wick Moor Drove (the plant approach road).
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology 18.7.19 Although the implementation of these measures would result in a large proportion of the hedgerows within the Development Site being lost, with the adoption of these environmental measures, overall the magnitude of effect is assessed as being moderate and impact rating of minor adverse significance. iv) Ponds and Watercourses 18.7.20 There are three ponds within the Development Site boundary: Pixie’s Pond, a scrub encroached (seasonal) field boundary pond and the pond at the sewage works for the power station (water features 2, 7 and 6 on Figure 18.11). Two of the pools are included within the CWS Boundary, and both have semi-natural aquatic vegetation, (common) amphibian populations and invertebrate interest. While falling within the boundary of the CWS, from an ecological perspective, these two ponds are considered to be of no more than local/parish importance. The other pond is a heavily shaded and scrub-encroached seasonal water-body with no associated ecological interest. It is considered to be of less than parish importance. 18.7.21 Watercourses within the Development Site are partially seasonal, show signs of agricultural improvement (poorly developed riparian and aquatic vegetation, limited freshwater invertebrate diversity, considerable poaching of margins by cattle, encroachment by ruderal vegetation etc), and support no protected species, apart from potential and occasional use by otter. Holford Stream feeds into the Bridgwater Bay SSSI and is of some importance in this context (as reducing flows may limit future management options within the SSSI – which is currently relatively dry in winter). This does not raise the ecological interest of Holford Stream, but potentially increases its ecological importance through its contribution to maintaining the integrity of the SSSI. The culverting of Holford Stream would still enable flow to be maintained and thus downstream hydrological connectivity would remain intact. However, clearly, culverting would result in the loss of the ecological interest of the watercourse. 18.7.22 Watercourses adjacent to the site, such as Bum Brook/Bayley’s Brook and the watercourse marking the northern boundary of the Bridgwater Bay SSSI (adjacent to the eastern part of the site) are of marginally greater botanical interest. 18.7.23 Flowing watercourses within the Development Site are of no more than parish value in terms of the vegetation they support. The loss or diversion of sections of these watercourses (a moderate magnitude effect) would be of no more than minor adverse ecological significance and no specific ecological mitigation measures are proposed. The culverting of Holford Stream and measures that would be undertaken to maintain flows to downstream areas is covered in the EnvApp Chapter on surface waters (see Chapter 15, Volume 2). Mitigation 18.7.24 The retention of much of the CWS to the east of the Development Site, will ensure that Pixie’s Pond and the pond at the sewage works will be retained. Only the small, ecologically impoverished pond will be lost during construction as it falls within the footprint of the construction area. The loss of this small pond, of less than parish value, would constitute a negligible impact. e) Habitat Networks 18.7.25 The mainly intact hedgerows that are present throughout the Development Site provide good linkages to on- and off-site woodland and to the coast. The approach road presents a barrier to movement between the site and the mosaic of habitats to the south of the power stations, but this effect is likely to be relatively limited for most species. The level of use by bats (including nationally scarce species) and the indicative age of some of the hedgerows suggest that they are an important connective feature for protected species dispersal.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 87 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.7.26 The water-courses are of less value than the hedges, and are only likely to complement the hedgerows to a minor degree. Their effectiveness as corridors is limited by their seasonality and lack of connectivity. There is little evidence of use of the watercourses by protected species. 18.7.27 Overall the habitat networks on site are considered to be of no more than local/parish value. Mitigation to deal with the function of the existing habitats as ecological corridors would be covered by the planned mitigation measures for the individual habitat elements as set out in the sections above and described in the section on operational mitigation measures. f) Effects of Habitat Loss on Notable Species i) Introduction 18.7.28 Surveys have found that badger, reptiles, bats and some notable species of invertebrates make use of the Development Site and potential effects on these species are considered further below. Dormice, great crested newts and water vole have not been recorded within the Development Site boundary, despite a survey programme conducted over several years. Otter makes transitory use of watercourse and water bodies on the peripheral parts of the site, with activity centred on the larger watercourses. There is very low or negligible potential for these species to be significantly affected by the development proposals and no further assessment of the proposed development on these species has been undertaken. ii) Badgers 18.7.29 The stripping of topsoil and the removal of hedgerow and woodland across the Development Site would result in the loss of and reduction in size of the territories of up to nine badger social groups. Badgers are protected on legal grounds, but are very common and widespread and of limited conservation interest. As such the ecological effect of development with regard to the badger ‘resource’ will be very limited, and will not be significant. Notwithstanding this, there is a requirement for mitigation in order to achieve legal compliance. 18.7.30 Badger mitigation (for welfare rather than conservation purposes) is considered in detail in a confidential report that has been submitted to Natural England, and will serve as the basis for attaining a mitigation licence. The mitigation strategy has been developed in association with Dr Julian Brown, a national badger expert, in consultation with Natural England and Somerset County Council ecologists. Measures will include relatively large scale sett creation, conversion of arable to pasture, planting of suitable shrubs and trees to provide additional foraging resources and artificial feeding. This combination of measures will address badger welfare issues and provide the basis for licensing. iii) Bats 18.7.31 There are ephemeral pipistrelle roosts in all three on-site barns that would be lost to development. Further, one confirmed tree roost and eleven medium to high potential roosts would also be permanently lost. The survey work has demonstrated that the southern part of the site supports low numbers of bats (with no roosts present), but that the network of woodlands and hedgerows in the central and southern part of the site provide regularly used corridors for a wide range of commuting and foraging bats. Foraging habitat is limited to boundary features and watercourse margins in addition to the mosaic of habitats to the south of the built plant. Lighting of the construction area could result in further displacement of light- sensitive bats (such as long-eared and lesser horseshoe bats) around the perimeter of the site and a barrier to movement across it. The habitats present within the Development Site are considered to represent a resource of importance to bat populations at the district/county level. 18.7.32 It is acknowledged that this valuation may reflect the lack of detailed contextual data that is available for lowland Somerset, and the bat population may be more typical of the wider lowland agricultural landscape than it is possible to conclude. It follows that if all roosting and
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology foraging habitats and, more importantly, the network of corridors across the site were to be lost, (prior to mitigation) that there is the potential for a moderate adverse impact on bats. Mitigation 18.7.33 Natural England have requested the retention of hedgerows running east-west across the Development Site and north-south within or adjacent to the site during the construction phase. This is primarily to allow bats, but also other mobile species, a clear route across the site and to the coast during the construction period. As noted in the mitigation for the botanical interest section, this will be satisfied by the retention of the hedgelines running along Benhole Lane, much of the east-west Green Lane and hedgerows linking this latter feature to Wick Moor Drove (the plant approach road). 18.7.34 It will be important to limit light effects on the retained hedgerows during the construction period. Light spill onto the hedgerows will result in some species (such as long-eared bats) avoiding them, thus reducing or negating their value as retained corridors. Lighting will therefore be positioned as far from the hedges as is conducive with security and engineering requirements and those lights closest to the features will take account of the following:
sodium lamps will be used. These are preferable to mercury or metal halide lamps (as they attract fewer insects away from the hedgerow, any insects drawn to the lights will only be available to light tolerant species); light intensity will be as low as is permissible; light spill towards the retained hedgerows will reduced to a minimum (using cowls as necessary); the height of the lighting columns will be modelled and optimised in order that extent of light spill can be clearly understood, and this can be used to demonstrate the likely effectiveness of the mitigation; and lighting should be motion or switch activated, as this will allow substantial periods of darkness during which bats can traverse normally. 18.7.35 The development will also result in the loss of three ephemeral common pipistrelle roosts, all in disused agricultural buildings. The loss of the roosts will be mitigated through the construction of a purpose built building in 2010 (prior to the demolition of the buildings) to act as a new permanent bat roost. The principal function of this building would be to provide an improved local roosting opportunity for common pipistrelle (the species which has been recorded roosting in the barns that will be removed), although it will be designed to incorporate features that could be used by a much larger range of species (such as Myotis, long-eared and horseshoe). The building will be located in a sheltered, unlit position on Benhole Lane as this is an existing bat corridor close to the buildings that will be lost. Supplementary planting of scrub around the building would darken the local area, making it more attractive to bats. Design and dimensions of the new building would be worked up in consultation with stakeholders, and would draw on best practice and examples of recent successful projects. 18.7.36 With respect to the loss of trees, each medium and high potential feature and the confirmed roost will be replaced by three bat boxes, resulting in a minimum of 54 boxes installed in Branland Copse and suitable trees along Benhole Lane (two boxes would be installed on each suitable tree to provide different climatic conditions). Where possible, existing features will be retained and re-attached to trees outside the construction boundary. 18.7.37 A licence will be obtained from Natural England to allow the destruction of the buildings with confirmed bat interest and removal of trees with significant bat potential. These works will occur during September – October or March – April to ensure that disturbance to any roosting bats in minimised.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 89 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.7.38 The implementation of these measures is assessed as having the capacity to reduce the overall potential magnitude of change for bat populations to a low level. Therefore, the residual effect would be one of minor adverse significance. iv) Reptiles 18.7.39 Grass snake and slow-worm are concentrated in the mosaic of habitats to the south of the built plant, with small numbers of slow-worm also occurring along a pocket of mature hedgerow on the east-west Green Lane. The population within the SSA is considered to be of parish importance. As the habitats within the SSA are fragmented from further areas of suitable reptile habitat near to the site, there are no alternative locations available to the reptiles that would be affected. Therefore, the loss of these habitats could result in the loss of the on-site reptile population and would be a high magnitude effect on a low/parish value receptor, resulting in an impact of moderate adverse significance. Mitigation 18.7.40 A low population of slow-worms is present on the east-west Green Lane and small numbers of slow-worm and grass snake occur in the habitat mosaic south of the existing plant. These features will be retained, which will allow these populations to persist and the existing level of interest would be largely maintained. Therefore, the magnitude of effect on the reptile populations would be reduced to low, resulting in a minor adverse impact on reptile populations. v) Invertebrates 18.7.41 Invertebrate interest is focussed on the better quality semi-natural habitats within the SSA. The areas of calcareous grassland have an associated butterfly fauna, while the mosaic of grassland, scrub and freshwater habitats to the south of the built plant have a relatively varied interest including several notable species, although at a district/county level, none of these species are known to be restricted to this site. Although the distributional extent of invertebrate populations associated with the habitats present within the SSA is not fully known, it is clear that such populations do occur and that similar habitats that could support these species occur outside of the SSA. Taking this into account, were all terrestrial and freshwater habitats within the SSA to be lost to development, this would constitute an effect of moderate magnitude and result in a minor-moderate adverse impact on invertebrate populations. Mitigation 18.7.42 As the vast majority of the habitats that support the notable invertebrate populations (e.g. glow worms, grassland/scrub butterflies) will be retained and remain unaffected by the proposed development, the overall magnitude of change would be low. The creation of habitat as part of the restoration plan would offer the opportunity for colonisation by a wide range of invertebrate species and potentially, over time, such areas could support assemblages of some interest, particularly in areas of calcareous/unimproved grassland and scrub. As such, the impact of the construction phase on invertebrate populations is assessed as negligible to minor adverse significance and no specific mitigation measures are proposed. g) Effects on Birds i) Terrestrial Birds 18.7.43 Within, and adjacent to, the Development Site Walkover survey data indicates that the construction of the new plant will lead to the loss of terrestrial habitat for a range of breeding, passage and wintering bird species. Breeding species affected would include skylark, linnet and yellowhammer (10 species recorded breeding in the survey area are listed as being of principal importance for nature conservation under the NERC Act), Cetti’s warbler (which is
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology subject to special protection under Schedule 1 of the Wildlife and Countryside Act 1981), nightingale and lesser whitethroat (which have relatively small populations at the county level). 18.7.44 Survey results also suggest that wintering and passage species would include mobile flocks of passerines associated with coastal fields/lowland farmland such as linnet, skylark and meadow pipit. Soil stripping would affect the extent of foraging habitat for most of these bird species, as invertebrates favouring both semi-natural habitats and the surface layer of soil would be lost. For granivorous species (e.g. yellowhammer) there would be a loss of cereal stubbles and weed seeds from crop edges and ruderal areas. Removal of woodland belts and hedgerows would also result in loss of foraging areas and shelter. 18.7.45 The breeding bird community of the entire SSA is of county importance. Development of the entire SSA, including the removal of all hedgerows, woodland and scrub would result in all terrestrial habitats suitable for breeding birds being lost. If this were the case, it is apparent that habitat used by a number of important breeding birds such as nightingale and Cetti’s warbler would be lost. Development of the entire SSA would lead to the loss of existing territories and the displacement of birds, potentially into areas where habitat is not suitable or unavailable. Although difficult to establish with certainty, loss of habitat and displacement could lead to an overall decline in breeding population levels for some of these species, whose habitat requirements are more restricted in occurrence, notably nightingale and Cetti’s warbler. If this were to occur this would constitute a medium magnitude effect and result in a moderate adverse impact. 18.7.46 The winter and passage bird community of the terrestrial habitats is of district importance. The displacement of birds from the entire SSA as a result of habitat loss/change would be likely to result in a minor-moderate adverse impact depending on the species involved. Mitigation 18.7.47 The network of rhynes and pools to the south of the built plant are of some importance to the Bridgwater Bay SSSI teal population. Numbers of teal exceeding 1% of the SSSI population have been recorded irregularly on the Sewage Works pool during winter, and smaller numbers use nearby rhynes. As there will be no development in this part of the SSA, there would be no adverse impact upon this wintering population or other birds that use this area. 18.7.48 With regard to terrestrial species, the avoidance of the mosaic of habitats to the south of the built plant would avoid the loss of habitat that is used by Cetti’s warbler, and those with nationally or regionally restricted populations (nightingale and lesser whitethroat). All three species predominantly occur in this area, although lesser whitethroat also occurs in some of the mature hedgerows on the north-eastern side of the Development Site. The avoidance of the most suitable habitat on site reduces the magnitude of effect for the entire bird assemblage to low, resulting in an overall minor adverse impact. 18.7.49 Within the farmland, breeding bird territories show a clear association with scrub, woodland belts and field boundary features (particularly hedgerows). To mitigate for potential destruction of the nests of breeding birds, hedgerow, woodland and scrub would be removed outside the breeding season (March to August). Where this is not possible, woody growth will be coppiced during the winter months and checks undertaken by an ecologist prior to removal to ensure that breeding birds are not present. 18.7.50 Very few ground-nesting birds were recorded within the SSA18, with the only species of conservation interest recorded nesting in open farmland habitats being skylark.
18 The exception is the mosaic of habitat to the south of the built plant. A number of species that breed on the ground or in low herbage are present including nightingale, willow warbler and chiffchaff.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 91 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.7.51 In the UK skylark tends to breed between late April and August, and may be double or treble brooded. In lowland Somerset, however, birds are often on territory by late February (Ballance, 2006) (Ref. 18.4) and breeding is therefore likely to conclude in July. Within the SSA the areas of highest skylark density are the larger arable fields, with far lower numbers in small enclosed arable fields and in pasture habitats. There are various potential options to mitigate effects on breeding skylark, one or more of which will be adopted to facilitate the soil stripping. These are outlined as follows.
soil stripping will be undertaken between August and early March; areas of pasture will be regularly cut throughout the growing season to prevent the development of the sward structure ground-nesting birds require to breed; an autumn-sown rye grass crop will be planted in any arable areas. By July this would have become tall and dense and would prevent ground-nesting birds from breeding (skylark also preferentially nest in fields of spring tillage – so a low number of birds would be expected to be present in the early part of the breeding season); and arable areas could be regularly ploughed prior to soil stripping to prevent a sward developing. 18.7.52 Removal of the majority of the woodland during the winter will prevent the destruction of the nests of breeding birds; where woodland is growing on badger setts, however, these will have to be closed under licence during the July to November period before the remaining trees can be removed. If this additional tree removal is undertaken during the spring, summer or early autumn (March to October inclusive), an ecologist would be present to conduct an initial survey and to ensure legislative compliance. The trees would be soft-felled (taken down in sections) to mitigate potential effects on bats and breeding birds. It is envisaged that it would not be possible to remove more than very limited sections of woodland in the period between mid March and the end of July due to constraints posed by breeding birds. The result of these mitigation measures would not alter the assessment outcome further but will ensure compliance with the Wildlife & Countryside Act 1981 (as amended). ii) Coastal Birds 18.7.53 The principal construction phase ornithological effects will arise through disturbance (e.g. through increased noise levels, lighting and general human activity) to those species that form part of the cited interest of the Severn Estuary SPA and Ramsar Site or the Bridgwater Bay SSSI and which occur in areas in close proximity to the proposed new sea wall and jetty. 18.7.54 Survey data indicates the cited species most likely to be affected by construction activity are wintering shelduck, wigeon, pintail and curlew, and passage whimbrel and ringed plover, as these species occur with relative regularity within a few hundred metres of the Development Site (notably the locations for the temporary jetty and the sea wall). Other species of note which occur and which make use of the intertidal adjacent to the proposed build area are herring gull and little egret. A roost of oystercatcher, a species which does not feature as part of the cited interest of any of the statutorily protected sites, is a regular feature of the intertidal to the west of the Development Site. 18.7.55 Intertidal habitats within 1km of the proposed development vary considerably in terms of the numbers of birds that they support. Nevertheless, all fall within the Severn Estuary Ramsar Site and SPA. Without mitigation being considered there is the clear potential for construction of the jetty and sea wall to cause disturbance to birds that may utilise the foreshore for roosting and/or feeding.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology 18.7.56 Specifically, the construction activities that have the greatest potential to cause disturbance and that are in close proximity to known areas of bird use (e.g. rocky intertidal to west of the site for the temporary jetty) are expected to be:
piling works for the temporary jetty; use of jack-up rigs, barges etc. during construction of the temporary jetty; and machinery and foreshore movement of people during construction of the sea wall. 18.7.57 There is relatively limited information on the potential of construction work to act as a disturbing activity on waterfowl populations, although studies on specific disturbance activities such as wildfowling, low-flying aircraft and human presence have been undertaken and provide some relevant data. Disturbance may reduce the feeding efficiency of birds and either force them to seek alternate feeding areas or increase their intake rates. Repeated disturbance may lead to birds not being able to maintain energy levels which in turn may affect the ability of some individuals to survive, particularly during cold winter weather when energy requirements are at their highest. 18.7.58 Generally it is accepted that birds tend to be more affected by the presence of people rather than noise from equipment. Disturbance is usually observed to lead to the interruption of birds’ activity patterns or for small-scale (i.e. short distance) displacement to occur away from the area of disturbance. Studies have also suggested that any effects are ephemeral and in only a small number of cases have disturbance events actually been shown to cause birds to permanently vacate a site. 18.7.59 Some evidence relating to the potential impact of construction noise and activity is available from the monitoring of emergency flood defence works carried out adjacent to the Humber Estuary SPA (Halcrow 1996). This revealed that wintering waterfowl numbers were slightly depressed during the initial period of works when the majority of the piling works for the defences were undertaken. The main effect was the partial displacement of birds from roosting and feeding areas within an area confined to 250m of the works. Worker activity and visibility was minimised during the works by restricting access to the top of the flood bank. The main species affected were wigeon and shelduck, but redshank, mallard and dunlin appeared to show no observed change in behaviour or numbers during the works. The overall conclusion of the study was that the impacts due to disturbance on the SPA designated populations were minimal (Halcrow 1996). 18.7.60 Monitoring of bird responses to construction work was also undertaken in relation to the development of a managed re-alignment site, also on the Humber (IECS 2003). This monitoring work revealed that despite the construction activity associated with the development of the managed re-alignment area, the disturbance effect on the avifauna using the fronting mudflats appeared to be relatively low. This was, in part, attributed to the fact that the mudflats fringing the construction site were quite extensive and the majority of construction plant and activity was to landward of the flood protection banks. However, disturbance to flocks of golden plover did occur behind the sea wall as a result of the transit of vehicles within the re-alignment area and the operation of back-hoes and cranes on the new embankment and existing flood defence line. The monitoring work concluded that the effect of construction activity was fairly restricted due to the timing of the works and the fact that there were sufficient areas of alternative suitable habitat available to minimise potential displacement of birds (IECS 2003). 18.7.61 A comprehensive study on the wider (i.e. population) influence of construction works on waterbirds was undertaken in relation to the construction of the Cardiff Barrage (constructed during 1991-1999). This work (Burton et al. 2002) found that over the construction period that the densities of several species of waterbirds (teal, oystercatcher, dunlin, curlew and redshank) on mudflats adjacent to the works decreased in comparison to pre-construction levels. Construction work was also observed to reduce the feeding activity of oystercatcher, dunlin and
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 93 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology redshank over these mudflat areas. Burton et al. (2002), on the basis of this work, suggest that disturbance from construction work may have the capability to decrease local habitat quality and as a result the ability for this habitat to maintain waterbird populations during construction. 18.7.62 The impact of disturbance effects during construction, as indicated by the IECS (2003) work is also likely to be influenced by the presence locally of alternative feeding and roosting areas. Where alternative areas are limited the significance of disturbance effects is likely to be increased. Given the relatively extensive nature of the mudflats adjacent to Hinkley Point and the availability of other foreshore and cliff top roosting areas within the local area this is unlikely to be the case. Although activity close to the development may cause birds to stop feeding and potentially take flight, they are likely to settle on nearby intertidal areas further from the activity. 18.7.63 In relation to the main intertidal bird survey area, shown on Figure 18.28, the jetty will be situated slightly west of the centre of Count Sector 2, while the new sea wall will join the existing plant sea wall along the uppermost section of the foreshore in Count Sector 3, and take in just less than half of the frontage of Count Sector 2. 18.7.64 A detailed assessment of the importance of all intertidal areas surveyed (in detail) to each of the cited and assemblage species of the Severn Estuary Ramsar Site and SPA, and the Bridgwater Bay SSSI as well as summaries of usage by non-citation waterfowl is contained in the report in Appendix 18d and in the baseline description in Section 4 of this Chapter. This information was taken into account in initial planning of the location of marine facilities to import construction materials into the site (see mitigation section below), and potential for disturbance to birds using the frontage was a consideration in the eventual siting of the facilities (i.e. the temporary jetty). 18.7.65 In relation to assessment of the potential disturbance effects of the temporary jetty and the sea wall, the following paragraphs summarise likely bird response within the vicinity of the development locations. 18.7.66 Ringed plover, if disturbed from Count Sector 1 (which would be approximately 500m west of the new jetty at its nearest point) would be likely to move further west. The nature of the coast between Count Sector 1 and Dunster (approximately 12km to the west) is similar to that within the sector in terms of aspect and composition (sandy coves/areas interspersed and separated by rock platforms). It is therefore reasonable to expect that birds would simply move into unoccupied areas of this relatively undisturbed shoreline. From the desk study, ringed plovers are already known to occur across this area, and the sporadic occurrence of the species in Count Sector 1 indicates that there are other locally suitable areas. Similarly, oystercatchers would be expected to move their roosting site further west onto other areas of upper shore rock that remain exposed at high tide. 18.7.67 Significant effects on whimbrel, curlew, wigeon and pintail appear similarly unlikely, given that the use of Count Sectors 1-3 is relatively limited. Whimbrel was the only species recorded foraging in these sectors with relative regularity (during spring passage). It is likely that the western edge of Steart Flats would provide a locally optimum foraging resource that will be attractive to the small number of birds that could potentially be displaced. It is considered likely that these species will either avoid moving into areas where they may be disturbed by staying further out in the channel (wigeon and pintail), or will be displaced further east onto the more extensive rock platforms of Sector 3 (some of which will be more than 500m from the sea wall and nearly all more than 500m from the jetty), and Sector 4, and the mudflats of Count Sector 5. 18.7.68 Taking into account the above information, the predicted construction methodology for the temporary jetty and sea wall, and the existing distribution and extent of bird usage it is
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology concluded that disturbance to birds during construction would constitute a temporary effect of low to medium magnitude, depending on where along the frontage construction works were to take place. This suggests that the potential level of impact ranges from minor adverse for those areas where bird usage is low (e.g. sectors 1-4) and moderate adverse where bird usage is higher (sector 5). The following aspects have been taken into account in this determination of potential pre-mitigation impact:
available information indicates that most birds appear to be relatively undisturbed by activities outside of a zone of approximately 200-300m and that human activity rather than noise is the key factor in causing disturbance; except for the far eastern edge of the SSA where recorded bird usage is relatively high, the numbers of birds within the potential zone of construction disturbance are small; significant areas of alternative habitat in and around the development site are available for birds that could potentially be disturbed by the construction activities; and, construction activity would not take place over the entire Development Site at the same time (i.e. disturbance activities would be concentrated in particular areas during specific periods). As such a potential zone of disturbance encompassing the entire area would not be present at all times. Mitigation 18.7.69 The main measure to provide potential mitigation of adverse effects to coastal birds has been achieved through the avoidance of those areas of intertidal habitat within 1km of the Development Site that hold large numbers of foraging birds throughout the year. With reference to Figure 18.5, it is clear that the edge of Steart Flats to the east of the built plant (Count Sector 5) is the most sensitive area in local ornithological terms, with some bird species moving onto adjacent rock platforms to the north of the built plant (Count Sector 4) prior to or following feeding. Initial plans to bring materials for construction in through this area via a flat-bottomed barge were discounted in favour of a temporary jetty, sited much further to the west, combined with a wharf upgrade for Combwich. This significantly reduced the potential for construction disturbance to occur within and/or adjacent to areas of habitat that support the highest numbers and diversity of SPA/Ramsar cited birds. 18.7.70 Although it is apparent that the potential for disturbance to birds has been substantially reduced as a result of siting of required facilities, it is still the case that some disturbance could occur. The assessment presented above indicates that the impact of this disturbance is likely to be limited. However, given the designated status of the bird populations using the foreshore area it is proposed that measures would be adopted to try and further reduce the potential for disturbance to birds to occur in the first place. 18.7.71 There are limited measures that can be undertaken to limit potential levels of activities likely to cause disturbance without compromising the ability to undertake these activities in an effective manner. The following measures would be adopted in order to minimise potential levels of disturbance.
the jetty will be of a simple solid design, with no hanging wires or other infrastructure that could potentially result in bird strike during low visibility conditions; noisy activities, such as piling works for the jetty and excavation of the foundations for the sea wall, will not be undertaken during the night; all piling work will be subject to a soft start up to allow disturbance sensitive species time to leave the vicinity of the works area prior to the most disturbing operations;
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movement by personnel outside of the footprint of the works (e.g. onto the intertidal rock platforms and open mud in Count Sectors 4 and 5, to the low water mark and west into Count Sector 1) will be restricted. A working area will be defined and demarcated for both the jetty construction and sea wall works. This is expected, in the case of the sea wall, to be restricted to a 30m corridor above Mean High Water; the temporary jetty will be constantly rather than intermittently lit during the construction of the new power station. This will be through the use of directional lighting (with cowling): so that only the jetty and immediate works area is lit and light spill into the intertidal is limited. This will allow bird species using the intertidal and inshore waters to habituate to the development area rather than being regularly displaced from roosting areas as a result of lighting that works on a motion or switch activated basis; and decommissioning of the temporary jetty could be undertaken at a time when effects on SPA, Ramsar and SSSI birds are likely to be minimised (e.g. starting in July). 18.7.72 While adopting these measures would not preclude the potential for disturbance, their implementation should limit the potential zone of disturbance and not lead to increased levels of disturbance further afield. Overall it is considered that adoption of the above measures would lead to, depending on the timing of the works and the species involved a negligible to minor adverse impact on coastal birds during the construction phase.
18.8 Operational Phase Effects
a) Key Activities during the Operational Phase 18.8.1 The development will result in the permanent loss of 65ha of agricultural land, (including those hedgerows and woodland located within the footprint). Potential significant effects could also arise from increased anthropogenic activity (such as patrols), light and traffic, and through potential effects of the discharge of warm water on intertidal communities. b) Approach to Mitigation during Operation 18.8.2 Due to the land take required for engineering the new plant, much of the mitigation will be delivered during the operation phase. Within the SSA this will be delivered through an updated ILMP that will take account of landscape, amenity and cultural heritage issues. Achieving practical and deliverable mitigation will also require input from ADAS, who are land managers for the existing stations, and from the site conservation warden. 18.8.3 The intention within the SSA will be to reinstate and manage a network of semi-natural habitats that are linked to each other, to the mosaic of habitats to the south of the built plant and to habitats in the wider area. The Sections below describe the mitigation measures proposed, however it is recognised that it will be several years before the mitigation is implemented and that biodiversity aspirations may alter in the intervening time period. Therefore, EDF will invite input from Natural England, Somerset County Council Ecologists, the Environment Agency and the Somerset Wildlife Trust in finalising the detail of this strategy post-consent, and a steering group will be set up to oversee the delivery of initial steps. c) Habitat Loss 18.8.4 Habitat loss would occur during the construction phase and no further habitat loss/alteration would be expected during operation. .The focus during operation is therefore on the delivery of appropriate mitigation largely via habitat recreation. The delivery of this mitigation with respect to each of the main habitat types that would be affected by the development is described and assessed in the following sections.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology i) Grassland 18.8.5 Calcareous grassland and lowland meadow are both UK BAP Priority Habitats, and are of value to invertebrates, particularly (in the context of Hinkley) Lepidoptera. Seed collected during 2008 and 2009 will be used to create new grassland areas on suitable substrates/subsoils (areas stripped of topsoil), and the development of this grassland and will be managed and monitored. An ‘off the shelf’ seed mix of local provenance will be used to achieve the extent of grassland outlined below. 18.8.6 Natural England and Somerset County Council have both requested that twice as much grassland be delivered post-construction as is lost (for the purposes of mitigation). Conservation gain requirements are additional to this. Approximately 6.8ha of species-rich semi-natural grassland would be required by way of mitigation. The intention would be to create a much larger area of semi-natural grassland, totalling 45ha with a additional 12.3ha of calcareous grassland. Approximately 8.8ha will be returned to agriculture. Linking this grassland to retained habitat corridors, new woodland, scrub and water features would maximise the effectiveness of this environmental measure. By providing a greater area of calcareous grassland than is lost, the magnitude of effect on this habitat type (assessed as being of medium biodiversity value) is reduced to low, resulting in a (minor) non-significant residual effect. Given the limited value of the remainder of the grassland within the Development Site, the restoration proposals to increase the amount of species-rich grassland would result in a minor, beneficial residual effect. (Note: Figures are approximate and subject to ongoing validation). ii) Woodland 18.8.7 To mitigate and provide conservation gain for the loss of the compartments of woodland in the coastal fields (currently approximately 7 hectares), a larger area of woodland will be planted within the construction area of the Development Site, equating to approximately 29ha (an increase of 400%). The woodland would include species that are typical of ancient semi- natural woodland in the vicinity of the site and coastal/lowland broad-leaved woodland in the county. The margins would be fenced to prevent grazing by stock and localised gap creation and restocking/natural regeneration as appropriate. To ensure that a range of micro habitats are available to invertebrates and other fauna, the woodland would not be planted as a linear or rectangular feature, but will have a scalloped margin (to maximise the length of woodland edge) and glades. 18.8.8 As a small amount of scrub will be lost as a result of development, new areas of this habitat type will be created around the edges of the new woodlands. Scrub will also be provided in areas of calcareous grassland to create a mosaic habitat that will benefit reptiles, invertebrates and birds. Species composition would reflect the County Wildlife Site. 18.8.9 The long-term provision of woodland and scrub, larger than is currently present within the site, is assessed as reducing the magnitude of effect on these low (district/parish) value receptors to low, resulting in a minor beneficial, residual effect. iii) Hedgerows 18.8.10 Following the construction of the new power station, much of the hedgerow network across all areas of the Development Site outwith the permanent footprint, will be reinstated. During the site restoration process, replaced hedgerows will be planted with a woody species mix that reflects the most species-rich hedgerows currently present within the Development Site. 18.8.11 The requirements of PPS9 in relation to biodiversity within developments will be satisfied by restoring and managing both the hedges and their margins with the aspiration of creating better habitat linkages and botanically diverse field edges. The latter can be accelerated through the
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 97 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology use of locally sourced seed mixes and the application of subsoil along hedge bases to help create ‘unimproved’ verges. This outline course of action (with regard to hedgerows) has been endorsed by Natural England. Whilst the total length of hedgerow restored following construction is less than the current amount of hedgerow present, additional edge habitat, which is similar in composition and structure to hedgerows, would be created along the margins of woodland and scrub. With these environmental measures implemented, it is assessed that the magnitude of effect on the hedgerow receptor of low (district) value, is reduced to low, resulting in a negligible-minor adverse residual effect. iv) Watercourses and Ponds 18.8.12 The landform of the restored site will preclude the reinstatement of Holford Stream and the creation of extensive wetland features, including watercourses, because the land will be higher than at present during operation of the site. Nonetheless, ditches will be created in association with hedgerows through the central part of the site (which will be at the lowest level). It is anticipated these will be seasonally wet and will feed water towards a wetland area in the area of cover crop for birds. 18.8.13 Additional mitigation for effects on watercourses will include improved management of Bum Brook adjacent to the southern boundary of the site (e.g. cutting of ruderal and scrub vegetation). The implementation of these measures reduces the magnitude of effect on watercourses to low. Given the low (Parish) value of the watercourses lost to development, this results in a minor adverse residual effect. 18.8.14 Natural England have indicated that their main concern from an eco-hydrology perspective would be that the rate of water flow into the SSSI is not diminished through changes to the Holford Stream (due to their aspiration to raise the water table on Wick Moor to ensure this part of the Severn Estuary SPA/Ramsar and Bridgwater Bay SSSI is in favourable condition). This will be primarily achieved through the design of the permanent Holford Stream culvert. However, there may also be an opportunity to increase flow to the SSSI by channelling run off from nearby car parks and the substation through a small area of new reedbed. These environmental measures are assessed as reducing the potential for a reduction in loss of flow to the SSSI to a level that would be unlikely to lead to an adverse effect on the hydrology of the aquatic habitats present within the SSSI. 18.8.15 Ponds are a UK BAP Priority Habitat. Therefore, despite the negligible (less than parish) value of the pond that will be lost, it will be replaced during the site restoration. To ensure conservation gain, it is suggested that one large reedy pond, similar in size to that at the Sewage Works of the operational plant, is created (possibly in conjunction with the above measure). An unspecified number of smaller ponds, more attractive to amphibians (most of which are UK BAP species) could also be incorporated, particularly if there was also an amenity element to the work. These ponds would be linked via semi-natural terrestrial habitats (such as hedgerows and associated field margins) to other features of conservation interest (preferably freshwater bodies). The creation of new ponds during the operational phase of the development is assessed as reducing the magnitude of effect to low, resulting in a minor beneficial residual effect. d) Notable Species 18.8.16 Effects on protected species during the operational phase will be limited. There is the potential for lighting of the plant approach road and the new plant to form local barriers to movement for some light-sensitive bat species; and for increased levels of disturbance close to the plant as a result of security patrols and greater traffic volume to result in an increased incidence of road kill, particularly in badgers.
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology e) Operational Effects on Birds i) Terrestrial Birds 18.8.17 Following the construction phase it is not anticipated that there would be any further effects of significance on terrestrial birds. Existing habitats that are known to be of value for breeding birds and which would be retained within the SSA would continue to be managed for their wildlife value. As such, the operational impact on the terrestrial bird fauna is assessed as being negligible. However, the overall impact of the construction phase (i.e. habitat loss) on terrestrial birds would essentially remain through into the operational phase and mitigation for this impact would therefore have to be implemented during operation. Mitigation 18.8.18 The reinstatement and improved management of hedgerows and the creation of a mosaic of new semi-natural habitats as part of the ILMP is likely to benefit many passerines (including a number of species of principal importance) during the breeding season, passage periods and in winter. This is reflected in the fact that the mosaic of habitats to the south of the built plant supports the most diverse bird community on the site, including the only Schedule 1 species in the area (Cetti’s warbler) and the locally notable nightingale and lesser whitethroat. 18.8.19 The site restoration will also provide a small number of arable fields near to the coast that will incorporate unfarmed conservation headlands to provide nesting habitat and food for farmland birds such as skylark and yellowhammer. A winter cover crop will also be sown to provide winter foraging for birds. 18.8.20 Management of hedgerows and new grassland creation will also create better foraging conditions for barn owl, and the erection of a nest box on a pole within the developing grassland would provide an opportunity for this species to exploit the food resource that would become available as rodent and insectivore numbers increased. The box would be located as far from the plant approach road as possible. 18.8.21 The site restoration will result in the establishment of semi-natural habitats which will increase opportunities for breeding birds. The magnitude of the overall effect of the restoration and creation of habitat is difficult to predict. Potentially, it is possible that overall conditions across the Development Site and the SSA could be improved on existing habitats in the longer term. If this is the case then a beneficial effect could be realised. Taking a precautionary approach, and allowing for establishment and that potentially habitats do not provide the required functionality it is predicted that the overall impact would be of negligible to minor adverse significance in the longer term. ii) Coastal Birds 18.8.22 There are a number of potential effects on coastal birds that may result from operational aspects of the development. The principal potential effect maybe as a result of change in the thermal regime of tidal waters overlying Bridgwater Bay. 18.8.23 Such a thermal change would not affect birds directly, but could potentially alter conditions that support the intertidal invertebrate communities that provide their food resource. 18.8.24 An assessment of likely changes to benthic communities as a result of thermal regime change has been undertaken (Volume 2, Chapter 19), the results of which are summarised on the following sections. 18.8.25 The worst case scenario warming effect, which would only occur if the Hinkley Point B Station were to continue to operate after commissioning of Hinkley Point C, shows that a very localised area (to the seaward side of Count Sector 4) would experience overlying warmed tidal waters up to 3C, waters over a very limited area of intertidal mud being warmed by up to 2C, while a
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 99 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology considerably larger areas of mudflat would be warmed by up to 1C. Hinkley Point B is currently scheduled to cease operations in 2019 but the operator may seek life extension of a few years. Thus for the moment no conclusion can be reached on the scale of influence that will actually occur. 18.8.26 The intertidal habitat at the western edge of Steart Flats (including Count Sector 5) has been classified as sandy mud, with the characteristic macrofaunal species present being the polychaete worm Nephtys hombergi and Baltic tellin (Macoma balthica). The benthic community is very limited in terms of diversity, and is typical of the wider Steart Flats, where surveys have found that M. balthica, H. diversicolor and H. ulvae make up 63%, 15% and 8% of overall biomass respectively. It is noted however that prey availability and biomass are not necessarily directly linked (BEEMS 2009 and BEEMS 2010) (Ref.18.44 and Ref. 18.45). 18.8.27 A detailed assessment of the apparent importance of all intertidal areas surveyed (in detail) to each of the cited and assemblage species of the Severn Ramsar Site and SPA, and the Bridgwater Bay SSSI, as well as summaries of usage by non cited waterfowl is contained in Appendix 18d. The key ornithological results in relation to the worst case thermal plume scenario are summarised as follows:
The western edge of Steart Flats, of which Count Sector 5 is part, regularly supports over 1% of the Severn SPA shelduck population during winter, with the largest flock recorded in Count Sector 5 during baseline survey work equating to slightly in excess of 8% of the SPA population. Outside the winter period, the area is also important for shelduck during the late summer, when moulting birds that form part of the Bridgwater Bay SSSI population are present. Shelduck predominantly feed on H. ulvae and small worms (Olney 1965, Bryant & Leng 1975, Evans et al. 1979, Buxton & Young 1981, Thompson 1982, Meininger & Snoek 1992 and Cadeé 1994) although there is doubt as to whether H. ulvae can provide the energy required to satisfy metabolic demand (Anders et al. 2008). M. balthica has only been recorded infrequently as a component of shelduck diet. Five of seven shelduck collected in Bridgewater Bay by Olney (1965) contained M. balthica, but they comprised just 7.3% of the volume of stomach contents; whereas all seven birds had ingested H. ulvae which made up 82.4% of the stomach contents. In 49 other samples from elsewhere in the UK (4 locations) Olney (1965) recorded no further instances of M. balthica being taken. Of 54 samples from Aberdeenshire analysed by Buxton & Young (1981) only 13 contained remains of Macoma. Shelduck diet is to some extent also governed by the method of feeding. Shelduck sift mud and water through the bill using the lamellae to filter out prey of the appropriate size. As shelduck discriminate against small and large prey items it is possible that the majority of the available biomass on Steart Flats is made up of individuals that are too large to be ingested by shelduck. The size range of prey taken varies between published accounts although in general it could be considered that prey items between 2mm and 4mm will make up the bulk of the diet (Warnes et al. 1980 from Thomson 1982, Buxton & Young 1981, Thompson 1982). The western end of Steart Flats is of importance to pintail, a species that Stroud et al (2001) (Ref. 18.42), suggested should be added to the Severn SPA qualifying interest through the SPA Review. Significant numbers of foraging pintail (between 1% and 8% of the SPA Review population) occur with regularity during winter. Pintail predominantly take Hydrobia in estuarine situations (www.jncc.gov.uk) although also have a high level of plant material in the diet (Snow & Perrins 1998); Curlew numbers on the Severn are nationally important, and the species is a recommended addition to the SPA interest (Stroud et al, 2001) (Ref. 18.42). Curlew is currently listed as a non-cited feature under Section 20 of the Ramsar Description; Count Sector 5 does not generally support numbers of curlew that exceed 1% of the SPA Review population (1
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ENVIRONMENTAL APPAISAL – VOLUME 2 18 Terrestrial Ecology instance was recorded during the baseline work), but more than 1% of the (revised) nationally important population quoted in the Ramsar description occurs with greater regularity. Curlew has been shown to take a wide variety of polychaetes, crustaceans and molluscs (including M. balthica) from various studies; Numbers of foraging whimbrel (during the spring passage period) and wigeon (during winter) regularly exceed 1% of the SSSI population (populations inferred from Section 20 of the Ramsar description). Whimbrel has a similarly catholic diet to curlew: it has been shown to include Nephtys (among other polychaetes), molluscs and crustaceans in UK situations (Snow & Perrins 1998); most prey is taken from at or near the substrate surface. Wigeon are almost exclusively herbivorous, and the regular presence of a feeding flock at low water indicates the presence of green seaweeds such as Enteromorpha or Zostera. 18.8.28 There are three possible mechanisms by which increased temperature may indirectly affect food availability for birds:
Increased temperature would increase metabolic rates of benthic microalgae during periods of immersion. This would not be compensated by increased photosynthetic rates, as the high turbidity of the water column will restrict photosynthesis to periods of emersion. This could lead to a loss of algal production. The extent of this effect would be predicted to decrease higher up the intertidal zone, as less time is spent underwater. These microalgae form part of the diet of grazing molluscs such as Hydrobia ulvae and Macoma balthica, and are a key component of the food chain that supports polychaete worms, all of which are important food sources for a wide range of estuarine birds; Benthic invertebrate sampling has established that M. balthica is the sole bivalve mollusc on Steart Flats. This species apparently has a temperature optimum located below the current mean temperature for the Severn estuary of 12.4C, and any increase in temperature may therefore reduce growth and increase mortality (BEEMS Report) (Ref. 18.43 to Ref. 18.45). The southern limit of M. balthica is currently at or above the latitude of the Gironde estuary in France. At Bourgneuf Bay (on the Gironde Estuary), the mean annual water temperature was reported to be 13.4 C; There is also potential for a positive effect upon the main predator of bivalve spat, the shrimp Crangon crangon. This species is abundant on the Flats during tidal immersion. In the Wadden Sea, shrimp abundance is higher after mild winters and laboratory experiments have shown a temperature optimum above 20C. Analysis of available information (BEEMS) (Ref. 18.43 to Ref. 18.45) suggests that a year- round increased temperature of 1-2C may be sufficient to cause a perceptible shift in intertidal ecosystem structure. Net primary production is predicted to decrease very slightly, and gastropods, small worms and meiofauna (small benthic invertebrates) may increase as M. balthica numbers reduce. Any changes in community composition would be of greatest magnitude on the lower and mid-shore where thermal plume effects would be most pronounced due to immersion time, and least on the upper intertidal. 18.8.29 The change to the intertidal benthic community would be subtle but most likely that the total availability of prey for species such as pintail, whimbrel and wigeon would remain unchanged or marginally increase; effects on these species are likely to be neutral or non-discernible. 18.8.30 Shelduck and curlew are the only two species recorded as taking M. balthica and therefore they are both at risk from a reduction in its density and/or availability. However the baltic tellin has not been shown to make-up the dominant proportion of the diet of any individual of either of these species on the Severn Estuary or further afield. If, as predicted, numbers of gastropods, small worms and meiofauna increase by exploiting the resource usually taken by Macoma there is likely to be no discernible effect on the amount of prey available to shelduck and curlew.
HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 101 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.8.31 Nevertheless, it is recognised that thermal regime change has the potential to affect the ecology of the intertidal mudflats, birds and fish that this habitat supports. Given the potential for this effect to impact upon the designated interests of the SPA/Ramsar site, further survey work and analysis is being undertaken to further refine the understanding of the ecological functioning of the intertidal systems involved. iii) Summary of Environmental Measures and Significance of Residual Effects 18.8.32 Table 18.8.1 evaluates the likely success of the mitigation measures proposed. Three types of mitigation have been recognised – avoid, reduce and compensate. Enhancement is used to describe environmental measures which provide a net benefit to a receptor that exceeds what is required for compensation, or to a receptor that is not adversely affected by a development. 18.8.33 The environmental measures proposed have been identified to address key potential ecological issues. For the purposes of assessment of residual effects it has been assumed that all of these environmental measures will be fully implemented, and the predictions and conclusions presented here are based on this assumption. 18.8.34 To take account of the fact that the impacts that occur during construction (i.e. habitat loss) would largely be mitigated through measures implemented during the operational phase of the power station, Table 18.8.1 provides a consolidated assessment of the residual effect from construction through into operation. This essentially reflects the situation that for the majority of the impacts on terrestrial ecology likely to result from the development the delineation between the construction and operation phase is largely irrelevant. Where it is clear that impacts are solely related to either the construction or operational phases and that any mitigation would be undertaken during these phases then this is clearly stated.
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Table 18.8.1: Summary of Significance of Environmental Impacts, Proposed Mitigation Measures and Significance of Residual Effects for Terrestrial Ecology
Receptor Predicted Potential Environmental Measures Incorporated Type of Likely Significance of Changes and Significance of Measure Residual Effect Following Potential Effect Prior to Mitigation Effects Mitigation
Grassland Loss of Minor – moderate Retention of over 40% of the CWS, including areas of Reduction and Minor beneficial grassland adverse species-rich calcareous grassland and collection of compensation (particularly seed from calcareous grassland that will be lost to be calcareous) used during site restoration. Restored site to include at least twice as much calcareous grassland as will be lost (restoration plan allows for approx. 12.3ha). The location of the calcareous grassland will be designed where possible to reduce fragmentation and to create a habitat link between the retained calcareous within the SSA and that present along the coast Restored site will also provide extensive areas of species-rich semi-improved neutral grassland. All grassland creasted will be managed for biodiversity.
Woodland and Loss of Moderate adverse Retention of over 40% of the CWS, including the Avoidance and Minor beneficial scrub woodland and most extensive areas of scrub within the SSA. Compensation scrub Creation of an area of woodland larger than that which will be lost. This to be one large and continuous area of woodland in the southern area, with smaller blocks in the northern part of the site. All areas of woodland will be linked to habitat corridors and preferably other semi-natural habitats created as a result of the proposal. Woodland composition to be based on species composition of naturally established (ancient semi-natural) Somerset coastal woodlands.
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Receptor Predicted Potential Environmental Measures Incorporated Type of Likely Significance of Changes and Significance of Measure Residual Effect Following Potential Effect Prior to Mitigation Effects Mitigation Planting of scrub around the edge of all new woodland planting (above) and to create mosaics in areas of grassland. Species composition to be based on the Hinkley CWS.
Hedgerows Loss of Moderate adverse Retention of one east-west and one north-south Reduction and Minor adverse hedgerow hedgerow; creation of planted strip along Bum compensation extent; Brook; re-planting of most hedgerows not affected by reduction in permanent land take post-construction; long-term effectiveness of management of hedgerows to create more diverse habitat margins that will provide better dispersal corridors opportunities.
Watercourses and Loss of ponds Minor adverse Ecologically significant ponds within the CWS would Reduction Minor adverse (watercourses) ponds and disruption be retained. One small, ecologically poor pond would Negligible (ponds) to existing be lost. Opportunities for the creation of new ponds watercourses within the restored site would be sought (e.g. culverting Culverting of Holford Stream would result in the loss of Holford of much of the existing watercourse. However, flow Stream) into downstream watercourses on Wick Moor (part of the Bridgwater SSSI) would be maintained.
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Receptor Predicted Potential Environmental Measures Incorporated Type of Likely Significance of Changes and Significance of Measure Residual Effect Following Potential Effect Prior to Mitigation Effects Mitigation
Species groups Reduction in Minor to moderate Retention of over 40% of the CWS, including the Reduction and Minor beneficial (bats, reptiles and extent of adverse majority of the botanical interest and all of the compensation invertebrates) available ecologically valuable ponds. habitat and Retention of much of the east-west Green Lane and populations. associated hedgerows. Creation and management of an extensively larger area of grassland (using seed from the CWS and an ‘off the shelf’ seed mix of local provenance). Planting of an area of new woodland using species typical of ancient semi-natural woodlands in the locality and planting scrub with a species composition typical of the CWS. The size of the woodland would exceed the area of woodland lost, and would be linked to existing boundary features.
Terrestrial bird Loss of habitat Minor to moderate Retention of over 40% of the CWS, including the Reduction and Negligible to minor adverse assemblage that supports adverse majority of the botanical interest and habitat used by compensation much of the the important bird species (e.g. nightingale and breeding bird Cetti’s warbler). interest Creation and management of an extensively larger area of grassland (using seed from the CWS and an ‘off the shelf’ seed mix of local provenance).
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Receptor Predicted Potential Environmental Measures Incorporated Type of Likely Significance of Changes and Significance of Measure Residual Effect Following Potential Effect Prior to Mitigation Effects Mitigation
Planting of an area of new woodland using species typical of ancient semi-natural woodlands in the locality and planting scrub with a species composition typical of the CWS. The size of the woodland would exceed the area of woodland lost, and would be linked to existing boundary features.
Coastal birds using Disturbance Minor to moderate Those areas within 1km of the Development Site Avoidance and Negligible to minor adverse intertidal areas at during adverse with the highest levels of bird interest (numbers and reduction Hinkley Point construction diversity) have been avoided. leading to The jetty will be permanently and directionally lit to displacement of encourage habituation and limit light spill into the foraging, intertidal. roosting and loafing birds. The jetty will be a solid simple structure with no overhead wires or other infrastructure that may result in bird strike during low visibility conditions. There will be no nocturnal piling or excavation of the foundations for the sea wall. There will be a soft start up for piling activities, and personnel movements will be restricted to a defined footprint around the jetty and sea wall (e.g. 30m). Deconstruction will be undertaken to a timing and methodology agreed with Natural England.
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Receptor Predicted Potential Environmental Measures Incorporated Type of Likely Significance of Changes and Significance of Measure Residual Effect Following Potential Effect Prior to Mitigation Effects Mitigation
Coastal birds using Disturbance Minor adverse The working areas will be permanently and Avoidance and Negligible intertidal areas at during directionally lit to encourage habituation and limit reduction
Hinkley Point operation light spill into the intertidal. leading to
displacement of foraging, roosting and loafing birds.
Coastal birds using Warming of Unknown at Further work to analyse the potential effects is being N/A Unknown at present time intertidal areas intertidal present time. undertaken. adjacent to Hinkley habitat as a
Point result of the outfall discharge, resulting in change to benthic communities forming the diet of bird species.
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HINKLEY POINT C PRE-APPLICATION CONSULTATION – STAGE 2 | 109 ENVIRONMENTAL APPRAISAL – VOLUME 2 18 Terrestrial Ecology 18.43 Bush, R., Griffith, A., Maxwell, T., Milligan, S., Payne, A., Schratzberger, M., Taylor, N & Warnes, S. (2009). Nearshore (sub-tidal) resources found during WP2 surveys of the Bridgwater Bay sampling area adjacent to the Hinkley Point power station site. BEEMS Technical report 083, Cefas. 18.44 BEEMS, 2009. Ecological characterisation of the intertidal region of Hinkley Point, Severn Estuary: results from the 2008 field survey and assessment of risk. EDF BEEMS (Cefas) Technical Report TR0Za 18.45 BEEMS, 2010. Impact of new nuclear build at Hinkley Point on intertidal food availability fro birds. EDF BEEMS (Cefas) Technical Report TR068A Literature Consulted ADAS. (2000). Hinkley Point: integrated land management plan. Report to British Energy. ADAS, Wolverhampton. Altringham, J. (2003). British Bats. Harper Collins. London. Archer, R. (In litt). Use of Steart Peninsula and Bridgwater Bay by winter, passage and breeding waterbirds. Report to Somerset Ornithological Society. Austin, G.E., Collier, M.P., Calbrade, N.A., Hall, C & Musgrove, A.J. (2008). Waterbirds in the UK 2006/07: the Wetland Bird Survey. BTO/WWT/RSPB/JNCC. Thetford. Banks, A.N., Collier, M.P., Austin, G.E., Hearn, R.D. & Musgrove, A.J. (2006). Waterbirds in the UK 2004- 05: The Wetland Bird Survey. BTO/WWT/RSPB/JNCC, Thetford. Bat Conservation Trust. (2007a). The state of the UK’s bats: National Bat Monitoring Programme Population Trends. The Bat Conservation Trust. Beebee, T.J.C & Griffiths, R.A. (2000). Amphibians and Reptiles. Collins London, New Naturalist Series. BEEMS, 2010. Inpact of new Nuclear Build at Hinkley Point on Intertidal Flood Availability for Birds. BEEMS Technical Report TR068A/CEEFAS. pp.35 Brown, A. & Grice, P. (2005). Birds in England. T & A.D. Poyser, London. Cabot, D. (2009). Wildfowl. Collins, London. Cefas. (2009). The effect of new nuclear build on the marine ecology of Hinkley Point and Bridgewater Bay. Report to EDF Energy. Cramp, S. (2000). Birds of the Western Palearctic. Oxford University Press, Oxford. English Nature. (2004). Bat mitigation guidelines. English Nature, Peterborough. Environment Agency/Babtie, Brown & Root. (2002). Stolford to Combwich Coastal Defence Strategy: Volume [http://www.environment-agency.gov.uk/static/documents/Research/ stolford_to_combwich.pdf.pdf]. Freitas, V., Campos, J., Fonds, M & Van der Veer, H.W. (2007). Potential impact of temperature change on epibenthic predator-bivalve prey interactions in temperate estuaries. Journal of Thermal Biology 32: 328- 340. Hockin, D. Ounsted, M. Gorman, M. Hill, D. Keller, V. and Barker, M.A. (1992). Examination of the effects of disturbance on birds with reference to its importance in ecological assessments. Journal of Environmental Management 36, 253-286. Institute of Environmental Assessment. (1995). Guidelines for Baseline Ecological Assessment. E&F Spon, London.
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