Tier 2

Operation and maintenance phase

Severity of consequence

558. Inch Cape makes landfall at Cockenzie within the Firth of Forth with no spatial overlap with the Proposed Development export cable corridor. Likewise, the inter-array cables for CEA tier 2 projects not considered in the equivalent impact for the Proposed Development in isolation (i.e. Inch Cape) will be located entirely within the array area, resulting in no spatial overlap with the Proposed Development export cable corridor.
559. Since there is no additional effect due to the presence of the CEA tier 2 projects, the most likely consequences associated with the maximum adverse scenario are as per the equivalent impact for the Proposed Development in isolation.
560. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

561. Taking into account the anticipated deviation options for vessel routeing with the presence of CEA tier 2 projects, the likelihood of an underwater allision incident may be exacerbated for the Seagreen offshore export cables due to vessels utilising the navigation corridor between the Proposed Development array area and Inch Cape. However, taking into account that vessels would generally cross perpendicular to the Seagreen offshore export cables (thus minimising time spent over any cable protection) and the charted water depth for the area (typically between 33 m and 61 m), the likelihood of an underwater allision incident remains very low.
562. Additionally, the same mitigation measures which are designed in for the Proposed Development will be applied for the Seagreen offshore export cables, including compliance with the guidance provided in MGN 654.
563. The frequency of occurrence is therefore considered to be extremely unlikely.

Significance of effect

564. Overall, the severity of consequence is deemed to be moderate and the frequency of occurrence is considered to be extremely unlikely. The cumulative effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

565. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Tier 3

Operation and maintenance phase

Severity of consequence

566. There is no overlap between the offshore export cables for CEA tier 3 projects and the Proposed Development export cable corridor, with Forthwind making landfall at Energy Park Fife within the Firth of Forth.
567. Since there is no additional effect due to the presence of the CEA tier 3 projects, the most likely consequences and consequences associated with the maximum adverse scenario are as per the equivalent CEA tier 2 impact.
568. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

569. Taking into account the anticipated deviation options for vessel routeing with the presence of CEA tier 2 and tier 3 projects, the likelihood of an underwater allision incident is determined to be as per the equivalent CEA tier 2 impact, including after consideration of the navigation corridor between the Proposed Development array area and Inch Cape.
570. The frequency of occurrence is therefore considered to be extremely unlikely.

Significance of effect

571. Overall, the severity of consequence is deemed to be moderate and the frequency of occurrence is considered to be extremely unlikely. The cumulative effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

572. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of mitigation is not significant in EIA terms.

Interaction with Subsea Cables

Tier 2

Operation and maintenance phase

Severity of consequence

573. A cable burial risk assessment is a standard requirement for all offshore wind farm developments. Therefore, it is assumed that for all CEA tier 2 projects the subsea cables will be suitably buried and protected with compliance with the guidance provided in MGN 654.
574. As per the equivalent impact for the Proposed Development in isolation, it is anticipated that the charting of infrastructure including all subsea cables will inform any decision to anchor, as per Regulation 34 of SOLAS (IMO, 1974) and noting that all CEA tier 2 projects are or will be charted.
575. With limited additional effect due to the presence of the CEA tier 2 projects, the most likely consequences and consequences associated with the maximum adverse scenario (underwater allision) are as per the equivalent impact for the Proposed Development in isolation.
576. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

577. Taking into account the anticipated deviation options for vessel routeing with the presence of CEA tier 2 projects, there is not considered to be any substantial increase in the likelihood of an anchor snagging (or fishing gear snagging) incident. This includes with consideration of vessels utilising the navigation corridor between the Proposed Development array area and Inch Cape; although the likelihood of a drifting allision incident is greater (as discussed in the cumulative impact for allision risk), it is assumed that any preventative emergency anchoring action would be undertaken following a check of the relevant nautical charts.
578. The frequency of occurrence is therefore considered to be negligible.

Significance of effect

579. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be negligible. The cumulative effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

580. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Tier 3

Operation and maintenance phase

Severity of consequence

581. The only CEA tier 3 project is Forthwind, located approximately 37 nm (69 km) from the Proposed Development array area within the Firth of Forth. Given the distance from the Proposed Development array area and that this project is located within a different sea area, the impact is considered only relevant for effects arising from project vessel movements and if operation and maintenance vessels operate in and out of ports within the Firth of Forth. In particular, Forthwind is located close to the Port of Methil and Energy Park Fife.
582. If project vessels were to operate out of these locations, there is a potential that third-party vessels intending to make berth at Methil may be unable to due to project vessel movements (including vessels which are RAM). However, any such scenario would be short-term, meaning that the need for anchoring may be limited. Furthermore, there are numerous designated anchorage areas within the Firth of Forth (including in proximity to Forthwind) which a third-party vessel would likely use.
583. Therefore, the most likely consequences associated with the maximum adverse scenario are as per the equivalent CEA tier 2 impact.
584. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

585. Accounting for the above scenario, the likelihood of an anchor snagging (or fishing gear snagging) incident is very low given that it is assumed that the subsea cables associated with Forthwind will be suitably buried and protected with compliance with the guidance provided in MGN 654. Moreover, any decision to anchor would be made following a check of the relevant nautical charts.
586. The frequency of occurrence is therefore considered to be negligible.

Significance of effect

587. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be negligible. The cumulative effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

588. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Reduction of Emergency Response Capability

Tier 2

Operation and maintenance phase

Severity of consequence

589. As with the equivalent impact for the Proposed Development in isolation, the presence of project vessels will increase the likelihood of an incident, with the potential to diminish emergency response capability. This will be exacerbated for the CEA tier 2 scenario given that project vessels will be present for multiple projects in the area, with Seagreen (already in situ) and Inch Cape in close enough proximity and large enough scale to have a notable effect.
590. Historical incident data indicates that the frequency of incidents in the area is relatively low and the majority of cases occur inshore of the Proposed Development array area, involving fishing vessels and recreational vessels. SAR helicopter taskings data indicates that the frequency of incidents in the area responded to by a SAR helicopter is relatively low.
591. The cumulative area to search across the Proposed Development array area and CEA tier 2 projects is very large (approximately 480 nm2 (1,684 km2) for the Proposed Development array area, Seagreen and Inch Cape alone). However, it is unlikely that a SAR operation will require a search of multiple arrays, noting that Seagreen and Inch Cape are located approximately 2.7 nm and 4.1 nm from the Proposed Development array area, respectively.
592. With the presence of the CEA tier 2 projects, the likelihood of an incident requiring emergency response will be greater given that some of the impacts already outlined (collision, allision, underwater allision and snagging risks). During consultation, the RNLI noted that this may change the general location of incidents in the area which may then require a review of the future location of emergency response assets.
593. However, project vessels will be managed by marine coordination and be compliant with Flag State regulations including the COLREGs. In particular, project vessels will be equipped to assist in the event of an incident, either through self-help capability or – in the case of a third-party vessel – through SOLAS obligations (IMO, 1974), in liaison with the MCA. From historical incident data, there are 13 known instances of incidents responded to by vessels associated with UK offshore wind farm developments. Therefore, the additional demand for dedicated emergency response assets is not likely to be substantial, particularly given that cumulatively there is an increased likelihood that a project vessel across the Proposed Development and CEA tier 2 projects will be able to respond.
594. In terms of internal navigation by SAR assets, Annex 5 of MGN 654 states that it is “highly likely that a helicopter refuge area will be required between adjacent developments” and “distances less than 1 nm are unlikely to be considered acceptable” (MCA, 2021). On this basis, the 4.1 nm separation between the Proposed Development array area and Inch Cape is considered a suitable helicopter refuge area, with SAR helicopters able to reorientate upon exiting one array and prior to entering another.
595. The most likely consequences are as per the equivalent impact for the Proposed Development in isolation, namely minor effects on business but no perceptible effect on people or the environment. For the maximum adverse scenario, a delay to an emergency response due to an inability to undertake an effective search could result in PLL and the environmental consequence of pollution. The Project’s Marine Pollution Contingency Plan will be implemented to minimise the environmental effects should pollution occur.
596. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

597. Historically, the rate of collision and allision incidents due to the presence of an offshore wind farm in the UK is low. Although the likelihood of an incident requiring an emergency response may be greater for the cumulative scenario given the increased presence of infrastructure and activities, this is offset by the greater ability to respond to a third-party incident due to greater presence of on-site project vessels.
598. The frequency of occurrence is therefore considered to be remote.

Significance of effect

599. Overall, the severity of consequence is deemed to be moderate and the frequency of occurrence is considered to be remote. The cumulative effect will, therefore, be of tolerable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

600. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Tier 3

Operation and maintenance phase

Severity of consequence

601. The only CEA tier 3 project is Forthwind, located approximately 37 nm (69 km) from the Proposed Development array area within the Firth of Forth. Given the distance from the Proposed Development array area and that this project is located within a different sea area, this impact is considered relevant in terms of the increased likelihood of an incident and subsequent stress on emergency response resources but not in terms of internal access to arrays.
602. As with the Proposed Development and CEA tier 2 projects, it is anticipated that the Inverness and Prestwick SAR helicopter service bases would be mobilised in the event of an incident within the Firth of Forth, although differing RNLI stations would likely respond. Given the small-scale of Forthwind, it is not anticipated that the effect on emergency response capability will be substantially increased compared to the equivalent CEA tier 2 impact. Therefore, the most likely consequences and consequences associated with the maximum adverse scenario are as per the equivalent CEA tier 2 impact.
603. The severity of consequence is therefore considered to be moderate.

Frequency of occurrence

604. Historically, the rate of collision and allision incidents due to the presence of an offshore wind farm in the UK is low. Although the likelihood of an incident requiring an emergency response may be greater for the cumulative scenario given the increased presence of infrastructure and activities, this is offset by the greater ability to respond to a third-party incident due to greater presence of on-site project vessels.
605. The frequency of occurrence is therefore considered to be remote.

Significance of effect

606. Overall, the severity of consequence is deemed to be moderate and the frequency of occurrence is considered to be remote. The cumulative effect will, therefore, be of tolerable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

607. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Interference with Magnetic Position Fixing Equipment

Tier 2

Operation and maintenance phase

Severity of consequence

608. Interference with magnetic position fixing equipment is local in nature, occurring only when a vessel is located in proximity to a subsea cable. Accounting for the distance between the Proposed Development export cable corridor and CEA tier 2 projects, it is therefore not anticipated that the presence of the CEA tier 2 projects will result in any change to the severity of consequence anticipated for the equivalent impact for the Proposed Development in isolation. This includes within the navigation corridor between the Proposed Development and Inch Cape; no subsea cables will be installed within the corridor from either project.
609. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

610. Accounting for the distance between the Proposed Development export cable corridor and CEA tier 2 projects, the likelihood of effect is not anticipated to be increased. Therefore, the frequency of occurrence is considered to be identical to the equivalent impact for the Proposed Development in isolation.
611. The frequency of occurrence is therefore considered to be negligible.

Significance of effect

612. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be negligible. The cumulative effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

613. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Tier 3

Operation and maintenance phase

Severity of consequence

614. The only CEA tier 3 project is Forthwind, located approximately 37 nm (69 km) from the Proposed Development array area within the Firth of Forth. Given the distance from the Proposed Development array area and that this project is located within a different sea area, the impact is considered to be identical to the equivalent CEA tier 2 impact.
615. The severity of consequence is therefore considered to be minor.

Frequency of occurrence

616. Again, due the lack of proximity of Forthwind, the likelihood of effect is considered identical to the equivalent CEA tier 2 impact.
617. The frequency of occurrence is therefore considered to be negligible.

Significance of effect

618. Overall, the severity of consequence is deemed to be minor and the frequency of occurrence is considered to be negligible. The cumulative effect will, therefore, be of broadly acceptable adverse significance, which is not significant in EIA terms.

Further mitigation and residual effect

619. No shipping and navigation mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 13.15   Open ▸ ) is not significant in EIA terms.

Transboundary Effects

620. A screening of transboundary impacts has been carried out and any potential for significant transboundary effects with regard to shipping and navigation from the Proposed Development upon the interests of other European Economic Area (EEA) States has been assessed as part of the EIA. The potential transboundary impacts are summarised below:

• vessel displacement for commercial routeing between international ports.
  621. Commercial vessels undertaking international voyages may be displaced due to the presence of the Proposed Development and CEA projects. Given the international use of AIS transceivers on commercial vessels, the baseline assessment of vessel traffic movements (Section 13.7) captures the relevant receptors for this transboundary impact. The impact has also subsequently been suitably considered for the cumulative scenario in section 13.12, concluding that the effect is of tolerable significance, which is not significant in EIA terms. Therefore, it can be concluded that there are no significant transboundary effects as a result of the Proposed Development.

13.3. Inter-Related Effects (And Ecosystem Assessment)

622. A description of the likely inter-related effects arising from the Proposed Development on shipping and navigation is provided in volume 3, appendix 20.1 of the Offshore EIA Report.
623. For shipping and navigation, the following potential impacts have been considered within the inter-related assessment:

• vessel displacement;
• increased vessel to vessel collision risk between a third-party vessel and a project vessel;
• increased vessel to vessel collision risk between third-party vessels;
• vessel to structure allision risk; and
• reduced access to local ports.
  624. No inter-related effects (Project lifetime effects) are predicted to arise during the construction, operation and maintenance phase, and decommissioning of the Proposed Development are predicted, since the potential impacts listed above will not be further exacerbated over the lifetime of the Proposed Development.
  625. As noted above, effects on shipping and navigation also have the potential to have secondary effects on other receptors and these effects are fully considered in the topic-specific chapters. These receptors and effects are:
• commercial fisheries;

–           Displacement from fishing grounds for commercial fishing vessels due to the presence of the buoyed construction and decommissioning areas during the construction and decommissioning phases, respectively.

13.4. Summary of Impacts, Mitigation Measures, Likely Significant Effects and Monitoring

626. Information on shipping and navigation within the shipping and navigation study areas was collected through desktop review, site-specific surveys and consultation, including vessel traffic surveys undertaken in line with the requirements of MGN 654 (MCA, 2021).
627. Table 13.20   Open ▸ presents a summary of the potential impacts, mitigation measures and residual effects in respect to shipping and navigation. The impacts assessed include:

• vessel displacement;
• increased vessel to vessel collision risk between a third-party vessel and a project vessel;
• increased vessel to vessel collision risk between third-party vessels;
• vessel to structure allision risk;
• reduced access to local ports;
• reduction of under keel clearance;
• interaction with subsea cables;
• reduction of emergency response capability; and
• interference with magnetic position fixing equipment.
  628. Overall, it is concluded that there will be no significant effects arising from the Proposed Development in isolation during the construction, operation and maintenance or decommissioning phases.
  629. Table 13.21   Open ▸ presents a summary of the potential cumulative effects, mitigation measures and residual effects. The cumulative impacts assessed are as per the assessment of the Proposed Development in isolation. Overall, it is concluded that there will be no significant cumulative effects from the Proposed Development alongside other projects/plans.
  630. The following potential transboundary impact has been identified in regard to effects of the Proposed Development and is considered to be of tolerable significance, which is not significant in EIA terms:
• vessel displacement for commercial routeing between international ports.

Table 13.20: Summary of Potential Environmental Effects, Mitigation and Monitoring

Table 13.21: Summary of Potential Cumulative Environment Effects, Mitigation and Monitoring

13.5. References

EDF (2020). Neart na Gaoithe Offshore Wind Farm - Construction Programme and Construction Method Statement. Revision 3.0. Edinburgh: EDF and ESB.

HM Government (2011). UK Marine Policy Statement. London: The Stationary Office.

IALA (2021 (a)). IALA Recommendation O-139 on The Marking of Man-Made Offshore Structures. Edition 3.0. Saint Germain en Laye, France: IALA

IALA (2021 (b)). IALA Guideline G1162 The Marking of Offshore Man-Made Structures. Edition 1.0. Saint Germain en Laye, France: IALA.

ICOL (2018). Inch Cape Offshore Windfarm (Revised Design) - EIA Report. Edinburgh: ICOL.

IMO (1972/77). Convention on International Regulations for Preventing Collisions at Sea (COLREGs) – Annex 3. London: IMO.

IMO (1974). International Convention for the Safety of Life at Sea (SOLAS). London: IMO.

MCA (2008). Marine Guidance Note 372 (Merchant and Fishing) Offshore Renewable Energy Installations (OREIs): Guidance to Mariners Operating in the Vicinity of UK OREIs. Southampton: MCA.

MCA (2014). National Contingency Plan: A Strategic Overview for Responses to Marine Pollution from Shipping and Offshore Installations. Southampton: MCA.

MCA (2021). Marine Guidance Note 654 (Merchant and Fishing) safety of Navigation: offshore Renewable Energy Installations (OREIs) – Guidance on UK Navigational Practice, Safety and Emergency Response. Southampton: MCA.

Nautical Institute (2013). The Shipping Industry and Marine Spatial Planning (MSP) – A Professional Approach. London: Nautical Institute.

PIANC (2018). Guidance on the Interaction between Offshore Wind Farms and Maritime Navigation. Brussels: PIANC.

RPS Energy (2020). Seagreen 2 Scoping Report. 1st revision. Abingdon: RPS Energy.

RYA (2019). The RYA’s Position on Offshore Renewable Energy Developments: Paper 1 (of 4) – Wind Energy. 5th revision. Southampton: RYA.

RYA (2019). UK Coastal Atlas of Recreational Boating 2.1. Southampton: RYA.

Scottish Government (2015). Scotland’s National Marine Plan.

Seagreen Wind Energy Ltd. (2020). Seagreen Offshore Wind Farm – Construction Programme (CoP). 3rd revision. Glasgow: Seagreen Wind Energy Ltd.

SSER (2022e). Cambois connection Scoping Report

Her Majesty’s Government (2011). UK Marine Policy Statement

UKHO (2021). Admiralty Sailing Directions North Sea (West) Pilot NP54. 12th Edition. Taunton: UKHO.

United Nations (1982). United Nations Convention on the Law of the Sea.

[1] C = Construction, O = Operation and maintenance, D = Decommissioning

[2] C = Construction, O = Operation and maintenance, D = Decommissioning

[3] In the event that the Project brings forward a single line of orientation layout post-consent, it is acknowledged that additional assessment will be required in line with MGN 654 requirements. This includes the undertaking of a safety justification to demonstrate that risk to navigation and SAR is ALARP, in consultation with the MCA.

[4] Dates cover construction periods for Seagreen 1 (2021 – 2023) and Seagreen 1A (2023 -2025).

[5] C = Construction, O = Operation and maintenance, D = Decommissioning