7.8. Key Parameters for Assessment

The Maximum Design Scenarios (MDS) identified in Table 7.7 Open ▸ are those expected to have the potential to result in the greatest effect on an identified receptor or receptor group. These scenarios have been selected from the details provided in volume 1, chapter 3 of the Array EIA Report. Effects of greater adverse significance are not predicted to arise should any other development scenario, based on details within the Project Description (volume 1, chapter 3) (e.g. different infrastructure layout), to that assessed here, be taken forward in the final design scheme.
The results of the physical processes assessment will be used to support and inform the following Array EIA Report chapters:

The physical processes pre-Scoping workshop (refer to Table 7.4 Open ▸ ) was used to facilitate stakeholder engagement on topics to be scoped out of the assessment.
On the basis of the baseline environment and the Project Description outlined in volume 1, chapter 3 of the Array EIA Report, a number of impacts were proposed to be scoped out of the assessment for physical processes. This was either agreed with key stakeholders through consultation as discussed in volume 1, chapter 5, or otherwise, the impact was proposed to be scoped out in the Array EIA Scoping Report (Ossian OWFL, 2023) and no concerns were raised by key consultees within the Ossian Array Scoping Opinion (MD-LOT, 2023).
These impacts are outlined, together with a justification for scoping them out, in Table 7.8 Open ▸ .

7.9. Methodology for Assessment of Effects

guidelines for the use of metocean data through the life cycle of a marine renewable energy development (Cooper et al., 2008);
guidance on Environmental Impact Statement (EIS) and Natura Impact Statement (NIS) Preparation for Offshore Renewable Energy Projects (Barnes, 2017);
guidance on Marine Baseline Ecological Assessments and Monitoring Activities for Offshore Renewable Energy Projects Parts 1 and 2 (Scally et al., 2018);
guidance on Best Practice for Marine and Coastal Physical Processes Baseline Survey and Monitoring Requirements to inform EIA of Major Development Projects (Brooks et al., 2018);
Offshore Wind Marine Environmental Assessments: Best Practice Advice for Evidence and Data Standards (Natural England, 2022); and
nature considerations and environmental best practice for subsea cables in English inshore and UK offshore waters (Natural England and JNCC, 2022).

In addition, the physical processes impact assessment has considered the overarching policy and legislation as described in volume 1, chapter 2 of this Array EIA Report.

The criteria for defining sensitivity in this chapter are outlined in Table 7.10 Open ▸ .

The magnitude of the impact and the sensitivity of the receptor are combined when determining the significance of the effect upon physical processes. The particular method employed for this assessment is presented in Table 7.11 Open ▸ .
Where a range is suggested for the significance of effect, for example, minor to moderate, it is possible that this may span the significance threshold. The technical specialist’s professional judgement was applied to determine which outcome defined the most likely effect, which took in to account the sensitivity of the receptor and the magnitude of impact. Where professional judgement was applied to quantify final significance from a range, the assessment has set out the factors that result in the final assessment of significance. These factors may include the likelihood that an effect will occur, data certainty and relevant information about the wider environmental context.
For the purposes of this assessment:

a level of residual effect of moderate or more was considered a ‘significant’ effect in terms of the EIA Regulations; and
a level of residual effect of minor or less was considered ‘not significant’ in terms of the EIA Regulations.

Effects of moderate significance or above are therefore considered important in the decision-making process, whilst effects of minor significance or less warrant little, if any, weight in the decision-making process.