15.11. Assessment of Significance

81. Table 15.8   Open ▸ summarises the potential effects arising from the construction, operation and maintenance and decommissioning phases of the Array, as well as the maximum design scenario against which each impact has been assessed. An assessment of the likely significance of the effects of the Array on the infrastructure and other users receptors caused by each identified impact is given below.

Displacement of Recreational Sailing and Motor Cruising, Recreational Fishing (Boat Angling) and Other Recreational Activities (Diving Vessels)

82. Construction, operation and maintenance, and decommissioning activities may lead to displacement of recreational sailing and motor cruising, recreational fishing (boat angling) and other recreational activities (diving vessels) due to the presence of the infrastructure safety zones and advisory safe passing distances in relation to the Array and may result in a loss of recreational resource.

                        Construction phase

                        Magnitude of impact

83. The installation of infrastructure in the Array may displace recreational activities from the footprint of the Array and from any areas subject to safety zones in place during the construction phase and advisory safe passing distances, resulting in a loss of recreational resource.
84. The maximum design scenario is represented by the installation of up to 265 floating wind turbines, up to 15 OSPs, up to 12 cable crossings of 1,261 km inter-array cabling and up to 236 km of interconnector cabling, with associated safety zones and/or advisory safe passing distances. Construction activities may take place over a period of up to eight years ( Table 15.8   Open ▸ ). During the site preparation, there may be up to 8 site preparation vessels on site at one time (2 survey vessels, 1 boulder clearance vessel, 2 geotechnical survey vessels, 1 sand wave clearance vessel and 2 UXO clearance vessels). There may be up to 97 vessels on site within the Array during the construction phase (including site preparation activities) at any one time, comprised of cargo barges, support vessels, tug/anchor handlers, cable installation vessels, guard vessels, survey vessels, CTVs, trenching support vessels, boulder clearance vessels, geophysical survey vessels and sand wave clearance vessels. It is likely that construction activity will be concentrated in certain locations at certain periods of time during the construction phase. Therefore, it should be noted that while up to 97 vessels may be on site at one time, the impact and safety zones in place will not be reflected and constant across the 859 km2 area of the Array.
85. As described in section 15.7, there are a number of recreational activities occurring in the vicinity of the Array, although as most activities occur closer to the shore it is unlikely that these activities will overlap with the Array. General sailing areas associated with ASYC and PSC are located 84 km and 90 km to the north-west of the infrastructure and other users study area – inner area, respectively. The closest general boating area is located at Montrose, approximately 97.1 km west of the infrastructure and other users study area – inner area (NMPi, 2023). Recreational fishing also occurs in the proximity of the Array.
86. The spatial extent of the impact on boating activities will be relatively small in the context of the available sailing and sea angling areas in the vicinity of the Array. There will be potential for localised displacement of recreational marine craft from the 500 m safety zones around the structures being actively installed within the Array. Additionally, there may be advisory safe passing distances in place around installation vessels operating within the Array. The impact of safety zones in place during the construction phase is mostly reversible as once each structure has been installed and commissioned these will be removed. Construction of the Array is expected to occur over an eight year period. The level of recreational activity within the Array is low, and recreational fishing is likely to be limited, giving a very low frequency of impact.
87. As described in Table 15.13   Open ▸ , NtMs will be issued regularly during the construction phase, advising of the location, nature and timing of activities associated with the Array, ensuring that recreational activities can be planned accordingly. The Applicant will also distribute Kingfisher notifications and other navigational warnings of the position and nature of works associated with the Array.
88. The impact is predicted to cause a minor shift away from the baseline, leading to a reduction in the level of recreational activity that may be undertaken for a short to medium term duration. The frequency of repetition is continuous, and the effect is not reversible for the construction phase. The magnitude is therefore considered to be low.

                        Sensitivity of the receptor

89. Recreational boating and sea angling vessels are able to alter their route or transit (dependent on their target destination) past installation activities and associated safety zones and advisory safe passing distances, given the adequate sea room around the Array. There are other locations available for sailing and sea angling such that alternatives are available if required during installation works.
90. The receptor is deemed to be of low value to the local economy and recreational activities are not generally vulnerable to impacts that may arise from the project and recoverability is high. The sensitivity of the receptor is therefore considered to be low.

                        Significance of the effect

91. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be medium. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

                        Secondary mitigation and residual effect

92. No infrastructure and other users mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in Table 15.13   Open ▸ ) is not significant in EIA terms.

                        Operation and maintenance phase

                        Magnitude of impact

93. The presence of the Array infrastructure and/or operation and maintenance activities within the Array may displace recreational activities from the footprint of the development and from any areas subject to safety zones or advisory safe passing distances during periods of major maintenance, resulting in a loss of recreational resource.
94. The maximum design scenario is represented by the presence of up to 265 floating wind turbines, up to 15 OSPs, up to 1,261 km of inter-array cabling with up to 12 cabling crossings and up to 236 km of interconnector cabling, with associated safety zones and/or advisory safe passing distances during periods of major maintenance, over a period of up to 35 years. There may be up to 31 vessels on site at any one time during the operation and maintenance phase, comprised of workboats/CTVs/Service Operation Vessel (SOVs), tug/anchor handlers, jack-up vessels, cable repair vessels, CSVs and DSVs. It is likely that vessel activities related to the operation and maintenance phase will be concentrated in certain locations at certain periods of time during the operation and maintenance phase. Therefore, it should be noted that while up to 31 vessels may be on site at one time, the impact and safety zones in place will not be reflected and constant across the 859 km2 area of the Array.
95. As described in section 15.7, there are a number of recreational activities occurring in the vicinity of the Array, although with most activities occurring closer to shore it is unlikely that these activities will overlap with the Array.
96. The spatial extent of the impact on boating activities will be relatively small in the context of the available sailing and sea angling area in the vicinity of the Array, with the potential for localised displacement of recreational craft around installed structures or around the individual 500 m safety zones and/or advisory safe passing distances temporarily and infrequently established around major maintenance activities. The level of recreational vessel and fishing activity in the Array is low and there will be no long-term exclusion of navigation within the Array during the lifetime of the Array (assessment of impacts on navigation is presented in volume 2, chapter 13).
97. As described in Table 15.13   Open ▸ , NtMs will be issued regularly during the operation and maintenance phase, advising of the location, nature and timing of any maintenance activities and associated safety zones/advisory safe passing distances, ensuring that recreational activities can be planned accordingly. The Applicant will also distribute Kingfisher notifications and other navigational warnings of the position and nature of works associated with the Array.
98. The impact is predicted to cause a minor shift away from the baseline, leading to a reduction in the level of recreational activity that may be undertaken for a medium term duration. The frequency of repetition is continuous and the effect is of not reversible for the operation and maintenance phase. The magnitude is therefore considered to be medium.

                        Sensitivity of the receptor

99. Recreational boating and sea angling vessels are able to alter their route or transit (dependent on their target destination) past maintenance activities and associated safety zones and advisory safe passing distances, given the adequate sea room around the Array. There are other locations available for sailing and sea angling such that alternatives are available if required during maintenance works.
100. The receptor is deemed to be of low value to the local economy and recreational activities are not generally vulnerable to impacts that may arise from the project and recoverability is high. The sensitivity of the receptor is therefore considered to be low.

                        Significance of the effect

101. Overall, the magnitude of the impact is deemed to be medium and the sensitivity of the receptor is considered to be low. The effect will, therefore, be of minor adverse significance, which is not significant in EIA terms.

                        Secondary mitigation and residual effect

102. No infrastructure and other users mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in ( Table 15.13   Open ▸ ) is not significant in EIA terms.

                        Decommissioning phase

                        Magnitude of impact

103. The effects of decommissioning activities within the Array are expected to be the same or similar to the effects from construction. The operational lifetime of the Array is expected to be 35 years. At the end of the operational lifetime of the Array, it is anticipated that any displacement of recreational activities would gradually decrease from the operational MDS as floating turbines and foundations will be fully removed from site and any driven piles or anchors will be cut down to seabed level and left in situ. This will be kept under review depending on current legislation and guidance requirements, best practice and other options may be required.
104. The decommissioning sequence will generally be the reverse of the construction sequence and involve similar types and numbers of vessels and equipment.
105. The impact is predicted to cause a minor shift away from the baseline, leading to a reduction in the level of recreational activity that may be undertaken for a short to medium term duration. The frequency of repetition is continuous and the effect is of not reversible for the decommissioning phase. The magnitude is therefore considered to be low.

                        Sensitivity of the receptor

106. It is anticipated that recreational boating and sea angling vessels will be able to alter their route or transit past installed structures and any decommissioning activities, given the adequate sea room around the Array. There are other locations available for sailing and sea angling such that alternatives are available if required during decommissioning works.
107. The receptor is deemed to be of low value to the local economy and recreational activities are not generally vulnerable to impacts that may arise from the project and recoverability is high. The sensitivity of the receptor is therefore considered to be low.

                        Significance of the effect

108. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be low. The effect will be, therefore, of minor adverse significance, which is not significant in EIA terms.

                        Secondary mitigation and residual effect

109. No infrastructure and other sea users mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in ( Table 15.13   Open ▸ ) is not significant in EIA terms.

Installation and Presence of the Wind Turbines, OSPs and Inter-Array/Interconnector Cabling within the Array, including Associated Safety Zones and Advisory Safe Passing Distances, may Affect or Restrict Access to Active Licence Blocks by Oil and Gas Operators either Temporarily or Long Term

110. Activities associated with the construction, operation and maintenance, and decommissioning phases may lead to the reduction or restriction of access to active hydrocarbon licence blocks by oil and gas operators. The MDS is represented by the greatest amount of the largest infrastructure and associated minimum spacing and the greatest extent of safety zones, over the longest construction, operation and maintenance, and decommissioning period represents the greatest potential for reduction or restriction of oil and gas exploration activities. This is summarised in Table 15.13   Open ▸ . An assessment of route deviations to vessels is provided in volume 2, chapter 13.

                        Construction phase

                        Magnitude of impact

111. The installation of infrastructure in the Array and associated presence of safety zones and advisory safe passing distances may displace oil and gas operators from carrying out activities within licenced blocks overlapping the Array.
112. The maximum design scenario is represented by the installation of up to 265 floating wind turbines, up to 15 OSPs, up to 12 cable crossings of 1,261 km inter-array cabling and up to 236 km of interconnector cabling, with associated safety zones and/or advisory safe passing distances. Construction activities may take place over a period of up to eight years ( Table 15.8   Open ▸ ). During the site preparation, there may be up to eight site preparation vessels on site at one time (including survey vessels, boulder clearance vessels, geotechnical survey vessels, sand wave clearance vessels and UXO clearance vessels). There may be up to 97 vessels on site within the Array during the construction phase (including site preparation activities) at any one time, comprised of cargo barges, support vessels, tug/anchor handlers, cable installation vessels, guard vessels, survey vessels, CTVs, trenching support vessels, boulder clearance vessels, geophysical survey vessels and sand wave clearance vessels.
113. The Array overlaps active hydrocarbon licence Blocks 27/3, 27/9 and 27/10, which are operated by North Sea Natural Resources Ltd (Licence number: P2321). As infrastructure in the Array is installed, the area available for seismic surveys and drilling will be restricted, and the presence of safety zones and advisory safe passing distances around infrastructure and vessels may also further restrict the ability to use certain alternative survey methods. The impact of safety zones and advisory safe passing distances is mostly reversible as once each structure has been installed and commissioned these will be removed. Furthermore, while the area for seismic surveys and drilling will be restricted during the construction phase, this will only be in concentrated areas of the Array and there will still be area available within these blocks for these activities. The greatest amount of the largest infrastructure and associated minimum spacing, and the greatest extent of safety zones over the longest construction phase represents the greatest potential for reduction or restriction of oil and gas exploration activities.
114. As shown on Figure 15.8   Open ▸ , there is no infrastructure associated with any oil and gas project within the broad infrastructure and other users study area, such that vessel access is not anticipated to be restricted to any existing oil and gas project asset.
115. The impact is predicted to cause a minor shift away from the baseline, leading to a reduction of access to active oil and gas blocks for a short to medium term duration. The frequency of repetition is continuous and the effect is not reversible for the construction phase. The magnitude is therefore considered to be low.

                        Sensitivity of the receptor

116. At the timing of writing this chapter, consultation with North Sea Natural Resources Limited identified that works at the appraisal well were completed in October 2023. The data from this work is under review before a decision on the next steps is taken.
117. It is anticipated that oil and gas operators will be able to alter their route or transit past installation activities and associated safety zones and advisory safe passing distances, given the adequate sea room around the Array.
118. In addition, the Applicant will continue to liaise with North Sea Natural Resources Ltd and other relevant oil and gas operators throughout the construction phase in order to understand any upcoming and/or planned oil and gas exploration activities to ensure limited interference and to facilitate coexistence.
119. The receptor is deemed to be of moderate value to the local economy and oil and gas activities are somewhat  vulnerable to impacts that may arise from the project and recoverability is moderate to high. The sensitivity of the receptor is therefore considered to be medium.

                        Significance of the effect

120. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be medium. The effect will be, therefore, of minor adverse significance, which is not significant in EIA terms.

                        Secondary mitigation and residual effect

121. No infrastructure and other users mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in ( Table 15.13   Open ▸ ) is not significant in EIA terms.

                        Operation and maintenance phase

                        Magnitude of impact

122. As described in paragraph 113, the presence of the Array and any safety zones and advisory safe passing distances associated with major maintenance activities may reduce or restrict the ability to carry out seismic surveys and drilling within the active hydrocarbon licence blocks overlapping with the Array during the operation and maintenance phase. The area available for seismic surveys and drilling will be restricted, however, there will still be area available within these blocks for these oil and gas exploration activities.
123. The maximum design scenario is represented by the presence of up to 265 floating wind turbines, with a minimum separation distance of 1,000 m, up to 15 OSPs, up to 1,261 km of inter-array cabling with up to 12 cabling crossings and up to 236 km of interconnector cabling, with associated safety zones and/or advisory safe passing distances during periods of major maintenance, over a period of up to 35 years. There may be up to 31 vessels on site at any one time during the operation and maintenance phase, comprised of workboats, tug/anchor handlers, jack-up vessels, cable repair vessels, CSVs and DSVs.
124. The spatial extent of the impact of the reduction or restriction of access to active hydrocarbon licence blocks by oil and gas operators will be relatively small. Any restriction of access with any safety zones or advisory safe passing distances around infrastructure and individual vessels carrying out major maintenance activities is mostly reversible as once these activities are completed and vessels move away from the area, all safety zones and advisory safe passing distances will be removed. Furthermore, any major maintenance activities are expected to be both temporary and infrequent. Any plans for new oil and gas infrastructure will be developed by oil and gas operators with an awareness of the Array. In the event that new oil and gas infrastructure is planned in close proximity, consultation will take place between the Applicant and the relevant oil and gas operator to establish close communication. Whilst not a legislative requirement, the NSTA interactive maps show the locations of wind farm developments. The greatest amount of the largest infrastructure and associated minimum spacing and the greatest extent of safety zones, over the longest operation and maintenance period represents the greatest potential for reduction or restriction of oil and gas exploration activities.
125. The impact is predicted to cause a minor shift away from the baseline, leading to a reduction of access to active oil and gas blocks for a long term duration. The frequency of repetition is continuous and the effect is not reversible for the operation and maintenance phase. The magnitude is therefore considered to be medium.

                        Sensitivity of the receptor

126. At the time of writing this chapter, consultation with North Sea Natural Resources Limited identified that works at the appraisal well were completed in October 2023. The data from this work is under review before a decision on the next steps is taken.
127. It is anticipated that oil and gas operators will be able to alter their route or transit past installation activities and associated safety zones and advisory safe passing distances, given the adequate sea room around the Array.
128. In addition, the Applicant will continue to liaise with North Sea Natural Resources Ltd and other relevant oil and gas operators throughout the construction phase in order to understand any upcoming and/or planned oil and gas exploration activities to ensure limited interference and to facilitate coexistence.
129. The receptor is deemed to be of moderate value to the local economy and oil and gas activities are somewhat vulnerable to impacts that may arise from the project and recoverability is moderate. The sensitivity of the receptor is therefore considered to be low.

                        Significance of the effect

130. Overall, the magnitude of the impact is deemed to be medium and the sensitivity of the receptor is considered to be low. The effect will be, therefore, of minor adverse significance, which is not significant in EIA terms.

                        Secondary mitigation and residual effect

131. No infrastructure and other users mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in ( Table 15.13   Open ▸ ) is not significant in EIA terms.

                        Decommissioning phase

                        Magnitude of impact

132. The effects of decommissioning activities within the Array are expected to be the same or similar to the effects from construction. The operational lifetime of the Array is expected to be 35 years. At the end of the operational lifetime of the Array, it is anticipated that any affects or restrictions to oil and gas operators would gradually decrease from the operational MDS as floating turbines and foundations are removed and any driven piles or anchors are cut down to seabed level and left in situ. This will be kept under review depending on current legislation and guidance requirements, best practice and other options may be required.
133. The decommissioning sequence will generally be the reverse of the construction sequence and involve similar types and numbers of vessels and equipment.
134.  The impact is predicted to cause a minor shift away from the baseline, leading to a reduction of access to active oil and gas blocks for a short to medium term duration. The frequency of repetition is continuous and the effect is not reversible for the decommissioning phase. The magnitude is therefore considered to be low.

                        Sensitivity of the receptor

135. It is anticipated that oil and gas operators will be able to alter their route or transit past decommissioning activities and associated safety zones and advisory safe passing distances, given the adequate sea room around the Array.
136. In addition, the Applicant will continue to liaise with North Sea Natural Resources Ltd and other relevant oil and gas operators throughout the decommissioning phase in order to understand any upcoming and/or planned oil and gas exploration activities to ensure limited interference and to facilitate coexistence.
137. The receptor is deemed to be of moderate value to the local economy oil and gas activities are somewhat vulnerable to impacts that may arise from the project and recoverability is moderate to high. The sensitivity of the receptor is therefore considered to be medium.

                        Significance of the effect

138. Overall, the magnitude of the impact is deemed to be low and the sensitivity of the receptor is considered to be medium. The effect will be, therefore, of minor adverse significance, which is not significant in EIA terms.

                        Secondary mitigation and residual effect

139. No infrastructure and others users mitigation is considered necessary because the likely effect in the absence of further mitigation (beyond the designed in measures outlined in ( Table 15.13   Open ▸ ) is not significant in EIA terms.