Abstract
1 Introduction
- Hornsea Project Three offshore wind farm (hereafter referred to as Hornsea Three) received development consent on 31 December 2020. A key issue raised by Natural England during the application process related to site-specific baseline data collected to inform ornithological assessments. Hornsea Three collected twenty months of site-specific digital aerial survey data which it presented, together with previous survey data collected for the Hornsea zone, as the baseline for the Hornsea Three ’s impact assessment, including HRA.
- Natural England objected on the basis that twenty consecutive months of digital aerial survey data were inadequate to fully characterise the baseline for key seabirds. Natural England noted that for the months of December, January, February and March, the baseline comprised a single year of site-specific digital aerial survey. Aerial survey data was supported by previous boat-based survey data from the larger Hornsea Zone used in the Hornsea One and Hornsea Two Applications, and included the Hornsea Three area. However, Natural England stated reservations with the previous zonal surveys being undertaken using a different methodology and had only achieved partial coverage of the Hornsea Three area. On this basis, Natural England’s position was that the baseline dataset did not capture the potential variability in densities during the months for which only one year of digital aerial survey data were collected.
- Following discussions throughout the application process, Hornsea Three commissioned further aerial surveys (‘Supplementary Surveys’) to cover the four calendar months which had only been surveyed once during the site-specific digital aerial survey campaign (i.e. Dec - Mar). These surveys were undertaken in 2019 and were used by Hornsea Three, in a contextual way, to demonstrate that the variability of the densities of key species in those months was limited and that the absence of two years of data for those months did not significantly increase uncertainty about the conclusions of the assessment1.
- Following receipt of the Hornsea Three Offshore Wind Farm Development Consent Order (DCO) for Hornsea Three, Natural England has submitted a request to the Secretary of State (BEIS) asking that Hornsea Three update collision risk and displacement estimates to incorporate the supplemental data collected during the Supplementary Surveys and to reflect Hornsea Three parameters consented in the DCO which were amended following a number of mitigation scenarios being adopted by Hornsea Three. The purpose of Natural England’s request is understood to be to incorporate all available data, to incorporate the turbine parameters included in the DCO and to inform other planned developments cumulative impact assessments.
- Hornsea Three has considered this request and has agreed, on this occasion, to provide the information requested by Natural England, as it is mindful that the information will be used for the Hornsea Four offshore wind farm DCO application which is due to be submitted in Q3 2021. Hornsea Three notes that the provision of updated collision risk modelling and displacement analysis post-consent is not normally carried out by offshore wind developers, and that Hornsea Three parameters are likely to be subject to further refinement (within the scope of the DCO) as development of Hornsea Three progresses. The provision of this information at this stage should not therefore be taken as precedent in relation to future requests. Hornsea Three does not propose to update collision risk modelling and displacement analysis again should further Project refinement take place.
- This report presents the results of collision risk modelling and displacement analysis for all species included in the original Environmental Impact Assessment (EIA) and Report to Inform Appropriate Assessment (RIAA) produced for Hornsea Three to incorporate the data from the Supplementary Surveys and to reflect Hornsea Three parameters consented in the DCO. During the Examination of the Application collision and displacement risks were calculated using different parameter assumptions which reflected the different positions of Hornsea Three, Natural England and the Examining Authority. The calculations in this report are also made using these same positions and assumptions, where relevant.
- The calculated effect estimates presented in this report are not considered to be meaningfully different in assessment terms when compared to effect estimates calculated previously. The assessments that have been presented previously and the associated conclusions drawn for both the EIA and HRA therefore remain unchanged.
This document is related to the Hornsea 3 Project Site.