DEV 3 Review and revise Strategic Risk Assessments, as new data becomes available or on a 6 yearly cycle, whichever is more appropriate DEV 4 Review and revise Local flood risk management Strategy and Flood Risk Management plan on a 6 yearly cycle. DEV 5 Use LFRMS to inform development of Local and Neighbourhood Development Plans, Drainage management and Maintenance Plans and programming; contingency plans and asset management plans. Tackling flood risk through improved understanding and raising awareness AWARE 1 Modelling Surface Water Flood Risk AWARE 2 Prepare Flood Risk Awareness Communications Plan AWARE 3 Publish significant flood incident reports AWARE 4 Publish significant flood risk asset register. Tackling flood risk through partnership working PART 1 Work in partnership with flood risk management authorities, stakeholders and relevant departments to address flood when it happens, and to ensure contingency plans is appropriate. PART 2 Work with Thames to mitigate and manage flood risk from manhole surcharge in Westminster. PART 3 Organise, attend and participate in flood risk management meetings such as Drain London/LoDeg, London Central North Flood Risk Group, internal Flood Risk Management Group,
Important and Public Realm Improvements: The LFRMS could affect important views and public realm improvements but these cannot be meaningfully assessed at SEA level in the absence of details. The effects on these views should be considered at project level. Consultation feedback (see Section 3), including updates to the environmental baseline and SEA ‘objectives’, have been incorporated into this ER. 2.3 Establishing SEA Objectives and Assessment Criteria An integral part of the strategy development process has been the identification of environmental issues that need to be addressed by future risk management, and which are fundamental to policy appraisal. These features were identified through data review and consultation with key external organisations. SEA objectives have been developed (Table 2.3) in order to assess the environmental effects of the LFRMS with consideration of the following: - Objectives used in the Integrated Impact Assessment of Westminster’s City Plan; Objectives developed for projects, in particular SEAs of surface water management plans, LFRMS SEAs; and The environmental baseline presented in Appendix A and summarised in Section 4. SEA assessment criteria (Table 2.3) were also developed to assess the LFRMS objectives and LFRMS ‘actions. Table 2.3 shows the main receptors that were considered in the SEA and associated questions that were addressed to determine the implications of the LFRMS for these receptors. The assessment criteria are posed as questions that focus on key issues for consideration during the assessment of options and description of environmental effects. They provide the framework upon which sustainable objectives for local flood risk management were developed and appraised. Table 2.3: SEA Objectives and their assessment criteria SEA Topic(s) Draft LFRMS SEA /Sustainability Objective Underlying Assessment Criteria Would the LFRMS, alone, or in combination with other plans… Population and Human Health To protect or improve health and Reduce the risk to people and human health from the effects of flooding? To protect and enhance important tourist and recreational amenities, and seek opportunities to increase open space throughout Impact on tourism or recreational pursuits in the long-term? Opportunities to create new/additional recreational facilities, or increase amenity/access to open space/green infrastructure/blue ribbon network? Have a positive impact on the local economy (e.g. through improved flood protection or enhanced recreation opportunities and green infrastructure provision)?
4 Baseline Environment 4.1 Existing Environment Relevant to LFRMS The baseline environmental data (including existing environmental and sustainability information) relevant to a range of environmental receptors is described in Appendix A ‘Baseline Environment’. A summary of the baseline environmental features and key issues in the study area that have been scoped into the SEA are presented in Table 4.1. 4.1: Summary of Baseline Environmental Features and Issues Scoped into Assessment Baseline Environmental Issues Likely Evolution of the Baseline Environment without the Population and Human Health Of the 219,400 resident population (Census 2011), 45,000 residents live within a high risk flood area Westminster is the most visited London Borough Westminster contains some of the most deprived areas in London e.g. Queens Park and Church Street Large area of recreation and open space (including Royal Parks, Blue Ribbon network of canals, rivers and lake, iconic public spaces and Green Infrastructure) in Central Westminster Direct effects on the population and properties within flood risk areas, including businesses and visitors in Westminster Quality of life is affected by flooding Overall shortage of open space in Westminster and access to these areas could be compromised by flooding Flood risk to important tourist, recreational and amenity resources Flood risk contributes to level of deprivation Population projected to rise by approximately 240,000 by 2031 (Westminster City Council 2012). Direct and indirect risks to human health from all flood sources likely to increase, and exacerbated by climate change; Tourism and associated recreational areas will continue to be affected by flooding. Increasing development will exert pressure on the floodplain. Material Assets 4 main rail termini and 32 underground stations 4 river bus piers and 157 bus routes passing through the city New development (e.g. crossrail) will be supported by upgrades to existing infrastructure Risk to existing, critical and proposed key transport infrastructure New development will need to be appropriately located in terms of flood risk from River Thames Climate change will increase to material assets and critical transport infrastructure (with associated capacity increases) affected by flooding. Proposed developments will require greater flood defences Biodiversity, and Fauna 1 Local Nature Reserve (St Johns Wood Church Ground) and over 40 Sites of Importance for Nature Conservation (SINCs) Potential for negative or positive effects on the LNR, SINCs and terrestrial, aquatic or riparian habitats. Need to ensure that flood risk measures do not adversely Climate change and land management activities will increasingly affect habitats Water dependent habitats will come under increasing pressure as demand for water increases.
Habitats and species of principal importance affect flow, frequency or duration of flooding to habitats. Soil, Geology and Geomorphology Floodplain gravels and alluvial deposits in the Taplow gravel in the central area around Paddington Basin and London Clay to the north One historic landfill site at Portugal Street near Holborn and potential for other areas of contaminated land Flood risk on soil quality, which could affect other SEA topics Geology can influence the extent and likelihood of an area to groundwater flooding and/or the suitability of some of SUD options. Soil erosion will continue due to surface water flash flooding and other causes Continued compaction and sealing through an increase in developed surfaces Potential flood risk to contaminated land or historic landfill Water Highly urbanised River Thames catchment with poor water quality Three Groundwater Source Protection Zones (SPZ) Two water bodies in strategy area – Thames Middle (estuarine, heavily modified) - Part of the Grand Union Canal (artificial) Direct and indirect effects on water resources, both surface and ground water, which could affect their ‘good’ chemical and ecological status as required by the WFD. Requirement for a preliminary WFD Assessment (see Appendix D). Water quality and water resources may increasingly be affected by urban flooding, which provides a potential pathway for pollution. Historic Environment Palace of Westminster and Westminster World Heritage Site Over 11,000 listed buildings, 56 Conservation 21 listed historic parks and gardens, five Royal Parks, 85 London Squares, 2 Scheduled Monuments, 5 archaeological priority areas and strategic or protected views. Non-designated sites and HER sites of national importance Historic landscape Unrecorded archaeological potential around the Thames foreshore and river walls Potential to reduce flood risk to archaeological assets Potential for impacts on the character of the historic landscape and archaeological assets and setting Historic environment will continue to shape the character of the borough Archaeological assets will continue to be threatened by development pressures, inadequate management of landscapes and inappropriate development. Potential loss or damage to historically significant features, particularly non-statutory historic buildings from increasing flood risk and indirect impacts e.g. from changes in water table levels. Townscape and Public Realm Settled, low scape townscape with relatively few buildings taller than six to eight storeys. Measures to reduce flood risk need to be sympathetic to the character of the townscape Increasing urbanisation increasing pressure on the skyline
Number of LFRMS measures that require habitat offsetting or mitigation [safeguard monitoring measure only - it is assumed that this monitoring will not be required as any action will be appropriately designed and implemented]. 5. To protect soil resources Potential for changes in soil quality, risk of soil contamination and change in organic debris of soil. [HIGH 3, RISK 2,3, HIGH 3,DEV4,5] Environmental assessment of detailed policy actions (including proposed location and nature of SuDS) to inform design choices. Number of LFRMS measures constructed on previously undeveloped land WCC 6. To protect surface and groundwater quality and support the objectives of the WFD Potential changes in flow regime and water quality. Uncertain whether actions and physical interventions will support WFD objectives or contribute to measures to improve the relevant water bodies. [HIGH 3; RISK 2,3; DEV4,5, PART 2] WFD compliance screening assessment of detailed policy options (including proposed location and nature of SuDS) will be undertaken at project and will inform design choices. Identify positive contributions to WFD objectives in relation to HIGH4; DEV1 DEV4 DEV6; PART6; RISK4; VUL1 VUL2 and VUL3. Number of LFRMS measures that improve or reduce the status of the water bodies. Ecological and chemical status of body Number of LFRMS measures that help restore riparian corridors, including floodplain connectivity and natural processes. WCC and Environment Agency 7. To conserve and enhance the historic environment, and Potential for positive or negative impacts on historic, archaeological, architectural or artistic Appropriate archaeological assessments during project level of detailed policy actions (including proposed location Number of heritage sites and Conservation Areas classified as ‘heritage at risk’. WCC
architectural, archaeological and cultural heritage interests, and their settings. [DEV1,5; RISK 2,3] and nature of SuDS and measures to reduce flood risk) to inform design choices. Consultation with English Heritage and City Archaeologist/ Conservation Officer. Number and condition of heritage assets and historic landscapes that are affected by the LFRMS, and that are at risk of flooding. Monitor development of English Heritage national guidance on development of SuDS and the historic environment, and its implications for relevant strategy actions. Number of enhancements to the historic environment as a result of LFRMS implementation English Heritage 8. To protect and enhance the unique setting and townscape character of Westminster Changes in character of townscape [DEV1,4,5 RISK1,2,3] Landscape and visual impact assessments (LVIA) undertaken, as appropriate, during project level of detailed policy actions (including proposed location and nature of SuDS and measures to reduce flood risk) to inform design choices, where actions involve new structures. Number of LVIAs undertaken as part of implementation of LFRMS measures Number of measures that enhance the existing character of the townscape WCC