Bridgwater Tidal Barrier Order Transport and Works Act 1992 Transport and Works (Applications and Objections Procedure) (England and Wales) Rules 2006 A17/1g Environmental Statement Volume 7 – Chapters 19 to 25 December 2019 19. In-combination effects 19.1 Introduction and scope 19.1.1 The Environment Agency, in partnership with Sedgemoor District Council, are delivering the Bridgwater Tidal Barrier (BTB) Scheme to reduce tidal flood risk to Bridgwater and surrounding areas. 19.1.2 Definitions of cumulative, intra-project and in-combination effects for the purpose of this Environmental Statement (ES) are provided in Chapter 7 (Environmental assessment methodology, Paragraph 7.5.2). Cumulative and intra-project effects are considered within the environmental topic assessment chapters (Chapters 8 to 18) of this ES, as required, and are therefore not discussed further here. 19.1.3 In-combination effects occur when the residual effects of a proposed development act in combination with the residual effects of other proposed projects to generate combined effects that are different or of a greater magnitude than the effects of the proposed projects alone. An assessment of in-combination effects considers other proposed and approved projects that have not yet been constructed and are not operational, i.e. developments that are in addition to the baseline. For proposed, but not yet approved projects, only those projects that have entered a formal process within the public domain are considered, e.g. projects undergoing public consultation, Environmental Impact Assessment (EIA) screening or scoping, a consenting process, or proposals that are identified in approved policies, plans or programmes. This is on the basis that these projects will have a reasonable certainty of being delivered and that sufficient information about them is available to enable a meaningful assessment. 19.1.4 This chapter considers whether in-combination effects could occur due to the interaction of the proposed Bridgwater Tidal Barrier (BTB) Scheme with other identified projects, and whether those interactions could generate effects of a magnitude and significance that would require BTB Scheme design amendments or other mitigation measures to reduce them to an acceptable level. 19.1.5 This chapter does not carry out strategic-level assessment of the combined effects of all known future projects or land-use allocations within the Bridgwater or Sedgemoor Local Plan areas, e.g. the total effects on current greenfield or brownfield sites. The focus of this assessment is to understand and manage the environmental risks from the BTB Scheme specifically as they act in-combination with other projects. 19.1.6 The potential for in-combination effects on Natura 2000 Sites has also been considered in the Report to Support a Habitats Regulations Assessment for the BTB Scheme (Appendix 9D of this ES). The Report to Support a Habitats Regulations Assessment has informed the assessment of in-combination effects on biodiversity within this chapter, where relevant. 19.1.7 The BTB Scheme includes carrying out works to weirs and other structures to improve fish passage along the River Parrett upstream of the barrier site (Chapter 18, Upstream fish and eel passage). Due to the small-scale nature of the fish and eel passage Bridgwater Tidal Barrier Environmental Statement 19- 1 proposals, the identification of potential projects where in-combination effects could result has been limited to any planned developments within 1km of the proposed works (Chapter 18 (Upstream fish and eel passage), Section 18.14). There are no approved or planned projects within 1km of the proposed works and therefore the fish and eel pass proposals have been scoped out of further assessment of in-combination effects. 19.2 Impact assessment methodology Identifying other projects 19.2.1 For in-combination effects to be generated, the residual effects of the construction and/or operational stages of the BTB Scheme must overlap spatially and temporally with the construction or operational effects of other planned projects. The following steps were carried out to identify projects with potential to have effects that spatially overlap with those of the BTB Scheme: . Identify spatial plans that may influence future development that could in turn interact with the construction or operational effects of the BTB Scheme. This was achieved through review of the Sedgemoor Local Plan documents (including supplementary planning documents) and liaison with Sedgemoor District Council officers. The identified spatial plans were reviewed to help identify projects that could interact with development and operation of the BTB Scheme. Identify all proposed, or approved but not completed, projects within 2km of the BTB Scheme. The 2km study area was determined having regard to the potential spatial area over which residual effects from the BTB Scheme could be detected. Projects were identified through interrogation of Sedgemoor District Council’s online planning application register and the Marine Management Organisation’s public register, consultation with Sedgemoor District Council, review of the identified spatial plans, and review of Environment Agency work programmes. Identify larger scale projects located further than 2km away from the BTB Scheme but whose nature and scale mean their effects could occur over a large enough spatial area to interact with the effects of the BTB Scheme; this was achieved through review of the National Infrastructure Planning portal, consultation with Environment Agency and Sedgemoor District Council technical specialists, review of the identified spatial plans, and via the EIA scoping process. 19.2.2 The above steps were carried out to inform the Preliminary Environmental Information Report (PEIR) (Environment Agency, 2018a) that was submitted in support of the EIA scoping process that took place in February to April 2018. The search of Sedgemoor District Council’s online planning register and the Marine Management Organisation’s public register, and consultation with Sedgemoor District Council, was repeated in 2019 to update the project list and project status. 19.2.3 The projects were reviewed to identify whether, based on their nature and scale, they would be likely to have any measurable interaction with the BTB Scheme at either construction or operational stages. Many of the proposed developments located within the 2km radius study area are small-scale commercial, agricultural or domestic projects (e.g. home improvement works). Such projects have been scoped out of the Bridgwater Tidal Barrier Environmental Statement 19- 2 assessment as they are considered to be too small to have any significant interaction with the effects of the BTB Scheme and therefore detailed assessment is not required. 19.2.4 When considering the scale of other projects to consider for in-combination effects, development type, area, and number of houses/industrial units was taken into consideration. For residential developments, this was considered as being the construction of 50 or more new residential dwellings within 2km of the proposed BTB Scheme works. Fifty residential dwellings was considered a suitable threshold as this is considered to be a significantly large enough development to generate effects which could give rise to significant in-combination effects. However, where a development of less than 50 residential dwellings is proposed along with additional supporting development, e.g. a school, this was considered for in-combination effects. Industrial, commercial and other infrastructure developments were assessed on a case-by-case basis. 19.2.5 The greatest potential for in-combination effects in relation to the BTB Scheme is from an overlap of construction phase effects which affect the same resource or receptor. Construction of the BTB Scheme is expected to start in 2022 with planned completion of the entire scheme in 2025. The identified projects were reviewed to determine whether they have potential to generate residual construction phase effects at the same time as the BTB Scheme based on the timing of proposed works. Any projects with no potential to generate construction phase effects at the same time as the BTB Scheme, and where the type of project means there is also no potential for in-combination effects from operation, were also scoped out of further assessment. 19.2.6 Plans identified for review are described in Section 19.3 and scoped in projects are described in Section 19.4. Projects whose status was reviewed between the scoping and detailed assessment stages and that have been scoped out of the assessment are described in Section 19.5. Appendix 19A provides a record of the scoping of projects that were identified from the Sedgemoor District Council planning register for this in-combination assessment. The scoping of identified larger scale projects that are not on this register are discussed in Sections 19.4 and 19.5 as appropriate. 19.2.7 Any new projects that come forward following the submission of this ES are expected to take the BTB Scheme’s anticipated effects into account when considering in- combination effects as part of the EIA undertaken for those projects. Assessment of in-combination effects 19.2.8 The following steps were carried out for each identified project: . Identify potential pathways through which the residual effects of the project and the residual effects of the BTB Scheme could interact to generate an in- combination effect. This was done by using the findings from the environmental topic assessment chapters (Chapters 8 to 18) of this ES, information in the consent application documents for the other projects, and other information in the public domain (e.g. posted on project websites). Where the BTB Scheme and Bridgwater Tidal Barrier Environmental Statement 19- 3 another project were identified as having a residual effect on the same receptor, then an assessment of in-combination effects was scoped in to the assessment. Consider the total change in environment brought about by each in-combination effect (considering scale, magnitude and duration) based on publicly available information.