Running Water Habitat

Nature Conservation Value and Conservation Status

221.           The Thornton Burn, Thurston Mains, Ogle Burn, Braidwood Burn, Skateraw Dean, Dry Burn and an unnamed watercourse run through the ecology study area. Rivers are a Priority Habitat listed on the SBL and Rivers and Burns are a priority habitat under the East Lothian LBAP. In total approximately 10.48 km of watercourses run through the ecology study area. The Proposed Development crosses the Skateraw Dean at the north and the Braidwood Burn at the south, with cable crossings proposed at each location. It is proposed to temporarily divert, or overpump, the unnamed watercourse to allow for open cut trenching technique and burying of this section of cable. The remaining watercourses lie outwith the footprint of the Proposed Development, however the Braidwood Burn flows into the Thurston Mains and Thornton Burn and Skateraw Dean flows into Dry Burn therefore these watercourses may be indirectly impacted.

Construction phase

Impact

222.           Impacts on the running water habitat will include temporary disturbance to the riparian habitat of Skateraw Dean and Braidwood Burn at the proposed cable bridge crossings. The unnamed watercourse will be temporarily diverted.

Magnitude of Impact

223.           As shown on Figure A7.4, Figure A1 and Figure A2, cable bridge crossings are proposed across Skateraw Dean and Braidwood Burn. The width of the temporary works areas for the cable bridge crossing at Skateraw Dean is approximately 70 m and works are to include the widening of an existing culvert to cross the burn. At the Braidwood Burn, where the proposed cable bridge crossing is to be constructed, the width of the temporary works area is 45 m. Assuming the works may impact running water habitat 30 m either side of the footprint of works at each site, a combined length of up to 235 m of this habitat may be susceptible to temporary disturbance. This represents 2.24% of the undesignated running water habitat within the ecology study area.  

224.           The cable route is then proposed to be installed using open cut trenching underneath the unnamed watercourse to the south of the A1, directly north of the onshore substation, as shown on Figure A7.4. The width of the temporary works area at this location is 100 m and the footprint of the cabling is approximately 30 m. As a worst-case scenario it is assumed that 100 m of running water habitat may be impacted at this location, though it is likely to be less as the width of the cable footprint is approximately 30 m. This represents 0.95% of the undesignated running water habitat within the ecology study area. 

225.           The impact is predicted to be of local spatial extent, short-term duration, intermittent and high reversibility. It is predicted that the impact will affect the receptor indirectly (Skateraw Dean and Braid Burn) and directly (unnamed watercourse). The magnitude is therefore considered to be negligible.

Sensitivity of the Receptor

226.           The running water habitat is deemed to be of medium vulnerability, medium recoverability and local value. The sensitivity of the receptors is therefore, considered to be low.

Significance of the Effect

227.           Given the above consideration of sensitivity and magnitude, the effect significance is considered to be negligible to minor adverse and not significant under the EIA Regulations.

Secondary Mitigation and Residual Effect

228.           No secondary mitigation is considered necessary because the likely effect in the absence of secondary mitigation is not significant in EIA terms.

3.3. Biodiversity Enhancement / Biodiversity Net Gain

229.           Chapter 7: Ecology of the EIA Report includes details of Habitat Loss and Mitigation (Table 7.20) that are likely to result from the Proposed Development based on the current indicative level of design. Included within Chapter 6: Landscape and Visual Impact of the EIA Report are outline landscape mitigation measures focussed on the substation where the majority of permanent habitat loss would occur. The outline landscape mitigation which includes habitat creation is set out in Figure 6.12 of Chapter 6 of the EIA Report.  In order to address consultee comments regarding the scale of the landscaping and enhancement opportunities the applicant has undertaken an Initial Biodiversity Net Gain Assessment based on the permanent habitat loss set out in the EIA and as amended through this Addendum (as noted in Section 3.2 and in Appendix 1). Based on a worst-case scenario this indicated that further habitat creation beyond that indicated in Figure 6.12 of Chapter 6 of the EIA Report would be required to deliver a net gain in biodiversity.

230.           In order to provide greater confidence that the Proposed Development can deliver biodiversity mitigation and enhancement for habitats which are permanently lost to development or for areas of temporary loss which require time to reinstate the Applicant has clarified that further land would be available for habitat enhancement and has updated Figure 6.12 of the EIA Report (as noted in Section 3.4 of Appendix 1) and as appended as Figure A6.12.

231.           The assessment, when considering the additional area available for potential habitat creation indicates that the use of around 60% of that additional available area for woodland and grassland creation would result in a 10% net gain in biodiversity value. For completeness, the assessment and a more detailed explanation of the assessment are appended to this Addendum as Appendix 1. Full details of habitat restoration (for areas of temporary loss) and of new habitat creation will be provided at a detailed design stage for agreement with ELC. The assessment will be updated on the basis of that detailed design in order to demonstrate a significant enhancement in biodiversity value in line with policy requirements.

3.4. Landscape Mitigation Plan

232.           The Initial Biodiversity Net Gain Assessment undertaken for the project (refer to Appendix 1 of this Addendum) confirms that additional habitat enhancement is likely to be required in order to meet the policy expectations set out in NPF4. As noted above additional land subject to temporary works as part of the substation development has been identified that could be utilised for additional habitat enhancement that would expand upon and complement the existing outline enhancement and landscaping proposals set out in Figure 6.12 of the EIA Report. The revised Figure A6.12 provided with this Addendum supersedes Figure 6.12 of the EIA Report. The landscape and enhancement proposals remain at an outline stage and will be refined through further detailed design following the granting of planning permission in principle.

4. References

EastCoastGridServices Ltd (2022), Branxton Energy Storage Facility Planning Statement.

Crystal Rig Wind Farm (Phase IV) (2018), CRIV EIAR Appendix 7 – Ornithology.

Figures

figure 1-6-1 cUMULATIVE EFFECTS ASSESSMENT ADDENDUM:   CULTURAL HERITAGE

figure A1: PHASE 1 HABITATS bRAIDWOOD bURN CROSSING

figure A2: PHASE 1 HABITATS SKATERAW DEAN CROSSING 

figure A6.12: OUTINE LANDSCAPE MITIGATION PRINCIPLES

figure A6.13: CUMULATIVE DEVELOPMENTS

figure A7.4 PHASE 1 HABITATS ECOLOGY STUDY AREA  

APPENDIX 1: ONSHORE INITIAL BIODIVERSITY NET GAIN ASSESSMENT

APPENDIX A11.1: FLOOD RISK ASSESSMENT

[1] The term ‘local area’ is assumed to be comparable to the ‘local’ study area assessed within volume 1, chapter 13: Socio-economics of the Onshore EIA report.

[2] Habitat IEFs not brought forward for assessment detailed in Table 3.2.