NORTH LONDON WASTE AUTHORITY NORTH LONDON HEAT AND POWER PROJECT ENVIRONMENTAL STATEMENT: VOLUME 2 APPENDICES 11.1 TO 11.3 AD06.02 NORTH LONDON WASTE AUTHORITY NORTH LONDON HEAT AND POWER PROJECT ENVIRONMENTAL STATEMENT: VOLUME 2 APPENDIX 11.1 WATER RESOURCES AND FLOOD RISK ASSESSMENT METHODOLOGY AD06.02 North London Waste Authority North London Heat and Power Project Environmental Statement Volume 2 Appendix 11.1 Water Resources and Flood Risk Assessment Methodology AD06.02 The Planning Act 2008 The Infrastructure Planning (Applications: Prescribed Forms and Procedure) Regulations 2009 Regulation 5 (2)(a) Issue October 2015 Amec Foster Wheeler E&I UK Ltd This report takes into account the particular instructions and requirements of our client. It does not in any way constitute advice to any third party who is able to access it by any means. Amec Foster Wheeler excludes to the fullest extent lawfully permitted all liability whatsoever for any loss or damage howsoever arising from reliance on the contents of this report. We do not however exclude our liability (if any) for personal injury or death resulting from our negligence, for fraud or any other matter in relation to which we cannot legally exclude liability. North London Waste Authority North London Heat and Power Project Environmental Statement Volume 2 Appendix 11.1 Water Resources and Flood Risk Assessment Methodology Contents Page 1 Water Resources and Flood Risk Assessment Methodology 2 1.1 Introduction 2 1.2 Engagement 2 1.3 Legislation and guidance 10 1.4 Baseline conditions 15 1.5 Construction and operational effects 16 1.6 Decommissioning effects 21 1.7 Cumulative effects 22 Issue | October 2015 | Amec Foster Wheeler E&I UK Ltd North London Waste Authority North London Heat and Power Project Environmental Statement Volume 2 Appendix 11.1 Water Resources and Flood Risk Assessment Methodology 1 Water Resources and Flood Risk Assessment Methodology 1.1 Introduction 1.1.1 This appendix sets out the methodology for assessing the likely significant effects of the Project on water resources (in terms of surface watercourses, groundwater flow, associated abstractions and discharges, water quality, designated sites, and wetland habitats) and flood risk. 1.1.2 This topic assesses effects on groundwater flows and quality as a result of activities at the ground surface, for example pollution of surface run-off. The Ground Conditions and Contamination section (Vol 2 Section 7) assess effects caused by changes to ground structure which could affect groundwater flow pathways and/or remobilise any existing ground contamination. 1.1.3 This appendix is divided into the following parts: a. engagement – describing a summary of comments included in the Scoping Opinion and through further stakeholder engagement and how these comments have been addressed; b. legislation and guidance – detailing requirements of the relevant National Policy Statements (NPS), how these have been addressed and additional guidance relevant to the assessment; c. methodology for establishing baseline conditions; and d. methodology for the assessment of construction, operation decommissioning and cumulative effects. 1.2 Engagement 1.2.1 Stakeholder engagement has taken place throughout the development of the design and environmental assessment. Vol 2 Appendix 7.1 provides a summary of the stakeholder engagement that has been undertaken in relation to groundwater, including comments on reports issued to the stakeholders and stakeholder consultation meetings. 1.2.2 A summary of water resources and flood risk specific engagement is provided in Vol 2 Appendix 11.1 Table 1. Vol 2 Appendix 11.1 Table 1: Water Resources and Flood Risk Technical Engagement and Scoping Responses No Organisation Comment Response (date) 1 Scoping Insufficient detail provided when: Further information regarding the Opinion: scoping out the potential effects surface water regime is provided in the Secretary of on water resources; and FRA (Vol 2 Appendix 11.2). State identifying that downstream These aspects have been scoped back (November in and are considered fully in this 2014) flow regimes would not be significantly affected by the assessment. Page 2 Issue | October 2015 | Amec Foster Wheeler E&I UK Ltd North London Waste Authority North London Heat and Power Project Environmental Statement Volume 2 Appendix 11.1 Water Resources and Flood Risk Assessment Methodology No Organisation Comment Response (date) proposed abstraction/discharge Air cooled condensers are proposed rates. as part of the Project. Two options for The proximity of sensitive the sourcing of water for these have receptors indicates the potential for been assessed as part of this ES. significant effects and there The proposed cooling water options remains the potential for water use will be discussed further with the EA. to exceed expected requirements or licensed limits. 2 Scoping Assessment required of potential The impact of climate change over the Opinion: groundwater pathway for discharge development lifetime has been Secretary of of liquids to surface and coastal considered within the FRA in line with State waters (including allowances for current guidance. (November climate change), including Contamination of groundwater (and re- 2014) engagement with the Environment mobilisation of ground contaminants) Agency (EA) to determine the has been addressed in Vol 2 Section 7 scope of the assessment as the (Ground Conditions and proposed development design Contamination). Climate change progresses. effects are considered within Vol 2 Section 11 (Water Resources and Flood Risk). Designs would be discussed with in the EA through ongoing engagement. The EA has been consulted in preparing the FRA (Vol 2 Appendix 11.2) and Hydrogeological Assessment (Vol 2 Appendix 7.2). 3 Scoping Full consideration required of the A comprehensive assessment of Opinion: potential effects of the cooling cooling water requirements, the Secretary of water connection on local intake/outfall locations, and the effect State hydrological and hydrogeological on the water environment has been (November resources. This will require: undertaken as part of this assessment. 2014) consultation with the Vol 2 Section 11 (Water Resources Environment Agency (EA) and Flood Risk) sets out details of regarding positioning of the proposed abstraction and discharge intake/outfall point; rates, including mains water, and the details of abstraction and outfall proposed intake and outfall points. rates to be defined and All three cooling water options have assessed; been considered in the assessment, and the options have been discussed agreement with the with the EA. Environment Agency (EA) that the rates are valid and the assessment represents the worst case; and the rate of mains water use to be clarified. 4 Scoping Flood Risk Assessment (FRA), The FRA forms an appendix to the ES Opinion: should form an appendix to the ES (Vol 2 Appendix 11.2) and is Secretary of and be cross referenced with other referenced in the discussion of flood State ES chapters. risk in the water resources (November assessment. 2014) 5 Scoping Should review River Basin WatFD requirements have been Response: Management Plan to determine considered in the water resources Page 3 Issue | October 2015 | Amec Foster Wheeler E&I UK Ltd North London Waste Authority North London Heat and Power Project Environmental Statement Volume 2 Appendix 11.1 Water Resources and Flood Risk Assessment Methodology No Organisation Comment Response (date) Secretary of how the Project can contribute to assessment. Consideration also given State, Water Framework Directive to the River Basin Management Plan Environment [WatFD] objectives. (RBMP) and the potential for the Agency Consideration required of the development to contribute to the (November requirements of the WatFD objectives. 2014) [WatFD]including causing no overall deterioration in water quality or the ecological status of any waterbody. 6 Scoping Flood risk and surface water A flood risk assessment for the Response: should be addressed in line with development has been prepared (Vol 2 Environment the requirements of the National Appendix 11.2). Agency Planning Policy Framework (November (NPPF) and the London Plan 2014) Policy 5.13. 7 Scoping Flood risk will need to be scoped These aspects have been scoped back Response: into the ES if works are proposed in and are considered fully in the water Environment to Enfield Ditch to ensure that any resources assessment. The impacts of Agency negative impact on people or the the Project on flood risk have been (November environment is avoided. assessed within the FRA and the ES 2014) (Vol 2 Section 11). 8 Scoping The FRA will need to consider the The FRA takes into consideration the Response: risk of fluvial flooding from the risks identified by the Greater London Greater nearby River Lee and Salmon’s Authority. The FRA is included as Vol London Brook systems, the risk of surface 2 Appendix 11.2. Authority water flooding and the risk of (January reservoir flooding from the range of 2015)1 raised reservoirs along the Lee Valley. 9 London Plan Policy 5.13 and the Sustainable Drainage Strategy has associated sustainable drainage been considered during design hierarchy should be applied to limit development. Surface water run-off surface water discharge to the would be limited as set out in the FRA, drainage system. Full in line with the London Plan and EA consideration required for guidance. rainwater harvesting systems. 10 Engagement Issues discussed at Environment Response: Agency (EA) consultation meeting Environment held on the 18 February 2015: Agency Consideration required of A Flood Risk Assessment (FRA) has (February desire to widen the entrance to been undertaken (Vol 2 Appendix 2015) the Edmonton EcoPark from 11.2) and considers the proposed Advent Way and the entrance works to the bridges. to the wharf area and to create Consideration of the requirements of a new crossing across Enfield the Water Framework Directive Ditch from Lee Park Way that (WatFD) within the Water Resources would contradict Water and Flood Risk assessment includes Framework Directive consideration of the new crossing and requirement for culverts to be entrance widening.