Contents Amendment Record

Transcription

1

2 Contents Amendment Record This report has been issued and amended as follows: Issue Revision Description Date Approved by Draft for CSG review Consultation Draft 30 April July 2010 M Phillips M Phillips 1 2 Final 20 Jan 2012 M Phillips Halcrow Group Limited Burderop Park Swindon Wiltshire SN4 0QD Tel +44 (0) Fax +44 (0) Halcrow Group Limited has prepared this report in accordance with the instructions of their client, Swansea and Carmarthen Bay Engineering Group, for their sole and specific use. Any other persons who use any information contained herein do so at their own risk. Halcrow Group Limited 2012

3 Shoreline Management Plan - Supporting Appendices This report is one of a series of appendices that provide supporting information to the Shoreline Management Plan (SMP2). This information has been provided to ensure that the rationale behind the decision-making process which leads to the preferred SMP2 policies is clear, transparent and auditable. The SMP2 appendices are as follows: A: SMP Development Provides an explanation of the SMP2 process, a description of the policy decision-making process and outlines the chronology of SMP2 development B: Stakeholder Engagement Presents the SMP2 stakeholder engagement process along with all relevant communication. This process is intended to build trust and understanding between all parties involved in the formation of an SMP, with the aim of being inclusive, transparent and appropriate in its methods and application C: Baseline Process Understanding D: Strategic Environmental Assessment (SEA) Scoping Report E: Policy Development and Appraisal F: Preferred Policy Scenario Testing Defines current understanding of how the coast functions, focussing on information that will inform decisions on future management of the coast over the SMP timescale to ensure that policy choices, in terms of coastal processes, are technically-sound and sustainable. This appendix includes the following: - Coastal Process and Shoreline Behaviour of Estuary Dominated Systems (prepared by Professor Ken Pye) - Assessment of SMP2 Boundaries - Defence Assessment - Marine Aggregates and Port Maintenance Annex - Marine Renewable Energy Proposals Annex - Integrated Coastal Zone Management Annex - No Active Intervention (NAI) and With Present Management (WPM) Baseline Assessments including NAI Figures (which define coastal erosion and flood risk) Provides the environmental baseline conditions of the study area against which the effects of the SMP can be assessed during the SEA. This appendix includes the following: - SEA Environmental Baseline Report (Theme Review) - Issues and Objectives Table - Legislation pertinent to the SEA process - Sites of Conservation Importance - List of Consultees Presents the consideration of generic policy options for each frontage, identifying possible acceptable policies, and their combination into scenarios for testing. Also presents the appraisal of impacts upon shoreline evolution and the appraisal of objective achievement. Presents policy assessment and appraisal of objective achievement towards definition of the Preferred Plan, as presented in the Shoreline Management Plan document.

4 G: Environmental Report (Strategic Environmental, SEA) To fulfil the requirements of the EU Council Directive 2001/42/EC (the Strategic Environmental Assessment Directive). H: Statement to inform a Habitats Regulations Assessment I: Water Framework Directive Assessment An assessment of the SMP2 in relation to the UK Habitats Regulations. This document provides Stage One of the Habitats Regulations Assessment (HRA). An assessment of the potential impacts of the SMP2 with respect to the Water Framework Directive 2000/ 60/ EC which provides a framework for the protection of inland surface, transitional, coastal and ground waters J: Economic Appraisal Presents the economic analysis undertaken in support of the Preferred Plan. K: Policy Sensitivity Analysis A review of the sensitivity of the SMP2 policies with respect to a range of issues. L: Metadata and Bibliographic Database Provides references for all supporting information used to develop the SMP for future examination and retrieval.

5 The structure of the SMP2 documents, and how they relate to each other, is summarised in the flow chart below. SMP Development (Appendix A) Stakeholder Engagement (Appendix B) Strategic Environmental Assessment (SEA) Scoping Report (Appendix D) Baseline Process Understanding (Appendix C) Policy Development and Appraisal (Appendix E) Preferred Policy Scenario Testing (Appendix F) Economic Appraisal (Appendix J) SEA report (Appendix G) Habitats Regulations Assessment (Appendix H) WFD Assessment (Appendix I) Policy Sensitivity Analysis (Appendix K) Metadata and Bibliographic Database (Appendix L) Policy Statements (Main Document)

6 Table of Contents J.1 APPROACH...1 J.2 USE OF EXISTING INFORMATION...2 J.3 DETERMINING DAMAGES AND BENEFITS...3 J.4 FUTURE COASTAL EROSION AND FLOOD RISK MANAGEMENT COSTS...6 J.5 ECONOMIC SUMMARY...7 J.6 SENSITIVITY ANALYSIS FUTURE SEA LEVEL RISE...12

7 J.1 Approach A review of economic viability has been carried out for the Preferred Plan and its associated policies. It should be noted that this review is not to establish the economic justification for a scheme as defined by Defra s Flood and Coastal Defence Project Appraisal Guidance Note 3: Economic Appraisal (FCDPAG3). The review instead makes a high level assessment of the economic robustness of the preferred policies, comparing the expected costs of defence with the value of assets at risk. The economic review therefore determines whether or not each policy is: Clearly economically viable; Clearly not economically viable; or, Potentially economically viable (and therefore may be in need of more detailed assessment at a later date, e.g. as part of a strategic plan, although some commentary on this is provided within this report). It must be recognised that the justification for a particular policy is not necessarily dependent on economic viability based on the benefit-cost ratio alone, as impacts on other benefits may be considered more important (e.g. holding existing defences to sustain a designated habitat) and at the high level of analysis undertaken at the SMP stage not all benefits are able to be evaluated in monetary terms. Although these other benefits have not been valued in monetary terms, they are taken into account during decision-making by considering whether they are likely to be sufficient to increase the benefits such that the benefit-cost ratio would be greater than unity. In 2007 a project led by WAG made three recommendations with respect to future priorities for flood risk management investment: the basis for assessing priority to be given to schemes should be primarily the numbers of people affected and the degree of that impact; the present rule that schemes must meet a cost benefit ratio of one to one or better should be relaxed to allow for other qualitative factors to be taken into consideration where appropriate; and future schemes should be prioritised using a new multi-criteria analysis that reflects both monetarised and non-monetarised impacts. The WAG Minister for Environment, Planning and Countryside accepted the recommendations and asked Flood Risk Management Wales and Environment Agency Wales to implement the first two recommendations with immediate effect. WAG propose to commission work to develop an appropriate multi-criteria approach to flood and coastal risk management investment decision making in Wales, informed by the emerging flood and coastal risk policy framework being developed by Defra in England. There is currently no recommended WAG guidance with respect to multi-criteria analysis of schemes. The following sections detail how the high level economic appraisal has been undertaken for the SMP2. This is followed by a table which provides for each policy unit a summary of the numerical analysis performed and a statement on the justification for the SMP2 policy. J-1

8 J.2 Use of Existing Information The following datasets were consulted to obtain information for the economic review: OS Addresspoint for property locations; for average property prices; The John Nix Farm Management Pocket Book, 40 th Edition (2010), September 2009, for agricultural land values; Flood Risk Estimating Guide for defence costs; Appendix C: Baseline Process Understanding to define area at risk from coastal erosion; and, Environment Agency Wales Flood Map to define area at risk from coastal flooding. Environment Agency Wales national data team were unable to provide National Property Database to Carmarthenshire County Council for use in SMP2 due to third party rights associated with Ordnance Survey and Valuation Office Agency data. This has limited the level of detail which can be provided in this appendix. J-2

9 J.3 Determining Damages and Benefits The benefits are the damages averted or delayed by the Preferred Plan, i.e. the difference in losses between implementing the Preferred Plan and the No Active Intervention (NAI) scenario. Since flood modelling data (to a suitable level of detail, including flood depth grid data) or the National Property Database were not made available for the SMP2 study area it was not possible to use MDSF to undertake the economic appraisal. The value of properties at risk, losses and benefits has been calculated on the basis of residential property values. For each policy unit the number and value of all residential properties and the number of residents at risk from flooding or erosion in the long term (100 years) has been defined using GIS and provided in Table J.2, based upon the following: Estimated average residential property value (Vale of Glamorgan, Bridgend, Neath Port Talbot, Swansea, Carmarthenshire and Pembrokeshire): 124,000 (accessed 23 November 2009); The average number of people living in a household in England and Wales: 2.36 (Office of National Statistics accessed 11 August 2009). Since the National Property Database was unavailable to the project team due to copyright issues and due to the wide variation in non-residential property value, which could comprise a corner-shop or a power station, it has not been possible to provide a value of nonresidential property which is at risk. However the number of non-residential properties at risk within each policy unit has been identified in Table J.2 and any significant properties have been referred to in the column entitled key infrastructure. The values of property losses do not take account of: residual life of existing defences; gradually increasing risk of coastal erosion or flooding to properties over time, or flood damages when the property is not written off and when the present value damages are lower than the market value of the property. Policy appraisal has determined a zone of likely future coastal erosion; for the purposes of estimating possible benefits the most landward extent of erosion, after 100 years, has been used in the analysis. In areas where there is a flooding risk, no attempt has been made to undertake detailed flood risk modelling; rather areas identified as at flooding risk by the Environment Agency Wales Flood Map (which shows the area which is at risk during a 0.1% annual probability of occurrence, 1 in 1000 year return period event, taking no account of existing defences) have been used to identify assets potentially at risk. The potential damages in these flood cells are simply taken as the summed value of all the at risk assets. This is based on the assumption that under a NAI scenario flood defences would fail and all at risk assets would be J-3

10 inundated and become uninhabitable. This is taken as an indicative figure for the value of assets potentially protected by defence structures. Due to the high level view adopted by the SMP review no account has been taken of standards of protection as it is only high level coastal erosion and flood risk management policy that is being determined. Standards of protection relate to implementation of these policies, which is usually undertaken within more detailed strategy level studies. Since the National Property Database was unavailable to the project team due to copyright issues it has not been possible to provide a value for key infrastructure which is at risk from coastal erosion and flooding within each policy unit such as utilities, highways and railway lines. However the key infrastructure within each policy unit has been identified in Table J.2. Intangibles, such as community/ social impacts upon the local economy or environment, have not been valued. However in some areas the justification for continuing to maintain or improve existing defences has been based on the tourist value of the area, asset or beach. For information a summary of the value of coastal tourism to the Welsh economy and within each local authority has been provided below. Agricultural Land Agricultural land values are highly variable depending on grade, location and size of lot and were extremely volatile in 2008 and A weighted average of 15,114 per ha has been assumed for grade 1 and 2 farmland. The growth in leisure and lifestyle purchases of farmland has seen prices significantly higher in recent years. This type of sale is more commonly grade 3 land which accounts for the difference in valuation between grades 1 and 3. Based on previous SMP valuations, a grade 3 valuation 6% higher than grade 1 was chosen and for grade 4/5 a valuation 4% lower than grade 1 was used. In accordance with the guidance in the Defra (2008), in following Scenario 1 (land is abandoned or no longer fit for agricultural use for the foreseeable future), land values were reduced by 600/ha to take account of subsidies, see Table J.1 below. Grade 1 and 2 Land Value ( /ha) 15, = 14,514 Grade 3 Land Value ( /ha) 16, = 15,421 Grade 4 and 5 Land Value ( /ha) 14, = 13,909 Table J.1: Average value of bare agricultural land, reduced to take account of subsidies Tourism Coastal tourism contributed 648 million to the Welsh economy in 2006 (Wales Coastal Tourism Strategy, WAG, July 2008). Approximately 33% of tourism revenue to Wales is generated in the South East Wales region; 50% of the overseas tourism revenue emanates from South East Wales and 64% of business tourism spend occurs in South East Wales (Bridgend County Borough Economic Partnership, February 2006). Tourism expenditure in the Vale of Glamorgan was million in 1994 (Vale of Glamorgan STEAM report, More than 1.3m tourists visited Neath Port Talbot J-4

11 County Borough in 2008 (29 Oct 2009, Tourism contributed over 300 million to the local economy of the Swansea Bay area in 2008 (News, April 2009, Carmarthenshire s tourism industry was worth 274 million in 2007 with 2.9 million people visiting the county (1 Sept 2008, Pembrokeshire tourism revenue was 521 million in 2008 (PCC, STEAM Report 2008). All Wales Coast Path No defences are proposed to reduce the risk of coastal erosion to the all Wales Coast Path. It is accepted that there will be instances of coastal erosion that will require the route of the path to be re-aligned. Any work undertaken to develop the all Wales Coast Path will have a design life of 25 years (Sue Rice, Access Programmes Manager, 23 Oct 2009). Railway Network Rail currently has no plans to realign any lines in South Wales in the short (20 years), medium (50 years) or long term (100 years) (Network Rail, 18 Nov 2009). Ministry of Defence In the short term (0 20 years) strategic facilities at both Pendine and Pembrey have important roles to fulfil. All Ministry of Defence sites are effectively under constant review, however the type of conflict that our armed forces are engaged in and the nature of the work carried out at these sites is unlikely to change significantly for the foreseeable future. J-5

12 J.4 Future coastal erosion and flood risk management costs Future coastal erosion and flood risk defence management approaches for each Policy Unit have been developed as part of the Preferred Plan. From this the high level replacement and maintenance requirements for each epoch have been determined. Future defence costs for an area have been generated using nationally available information. Cost Rates Replacement costs for general defence types have been taken from Environment Agency s Unit Cost Database (Environment Agency, 2007). This suggests average replacement costs for linear structures (e.g. seawalls, revetments, groynes and beach recharge) are based on costs incurred on recent Environment Agency projects. Maintenance costs have been taken from the Defra National Appraisal of Defence Needs and Costs (NADNAC) study (Defra 2004). Updated to current values using the Public Works Non Road (PWNR) index, this suggested annual maintenance costs for linear structures at 12,000/km. Cost Calculations It has been assumed that the timing of full scheme reconstruction required (i.e. design life) is at least once every 50 years for linear defences, such as seawalls, revetments and embankments. However, these periods may become more frequent for areas where erosion potential is high. Maintenance has been assumed to occur to the same level in every year throughout the life of the scheme. In reality, this will be less in the early years and will increase in later years of the scheme s life. However, for the high level appraisal undertaken for the SMP this will make negligible differences to decisions as the highest costs are associated with capital works. Allowance has also been made for the increase in costs due to climate change and sea level rise, based upon factors developed for the NADNAC study. This takes account of the need to make structures higher, deeper, and more resilient to increased exposure. The assumptions were: no cost increase for the 0-20 year epoch; costs factored up by 1.5 times present day rates for the year epoch; and costs factored up by 2.0 times the present day rates for the year epoch. In accordance with the latest Defra and HM Treasury guidance, Optimism Bias (OB) was applied to all costs (at 60%) to reflect uncertainty in the high level analysis at the SMP scale. No costs have been attributed to dune management (managed realignment) since the selection of this policy option is typically linked to environmental management of the site and is not sensitive to the benefit cost ratio. Otherwise where the preferred option is managed realignment, costs have been based on the capital value and maintenance costs of assumed alignments of potential set back embankments/ seawalls. These alignments and costs are subject to uncertainty since further detailed studies would be required to confirm the requirements of a particular managed realignment scheme. J-6

13 J.5 Economic Summary A summary of the economic review of the preferred SMP2 policies for each Policy Unit is provided in Table J.2 overleaf. It defines the number of residential properties, residents, nonresidential properties (see Figure J.1), agricultural land and key/ strategic infrastructure which are at risk from coastal erosion and flooding in the long term (100 years). The number of residential and non-residential properties which are at risk during a 1 in 1,000 year return period extreme tide event, excluding sea level rise, taking no account of existing defences, is 12,927 and 2,592 respectively. The estimated number of residential and non-residential properties which are at risk from coastal erosion alone over the SMP2 period (100 years) under the preferred SMP2 policies are 195 and 99 respectively. The economic review also includes an initial appraisal of undiscounted benefits and costs associated with the preferred SMP2 policies. Figure J.1: Number of residential and non-residential properties which are at risk from flooding during a 1 in 1,000 year return period extreme tide event, excluding sea level rise, taking no account of existing defences J-7

14 J-8

15 J-9

16 J-10

17 J-11

18 J.6 Sensitivity Analysis Future Sea Level Rise In response to queries raised by the CSG, a high level sensitivity analysis was undertaken to define the additional number of residential and non-residential properties which are at risk from 1m future sea level rise (Defra 2006 guidance) and 2m future sea level rise (the UKCIP09 estimate for average sea level rise around the UK from the melting large ice sheets, which cannot be ruled out, but recent observations and model projections do not provide evidence that it will occur). LiDAR topographic data (obtained from the Environment Agency Wales - it should also be noted that there are gaps in the LiDAR data provided) was used to define the area which is at risk from tidal flooding, following the failure of existing defences, during a 1 in 1000 year return period event, including 1m and 2m sea level rise. The extent of flooding is a high level approximation, based upon extreme still water levels alone and takes no account of wave action, flooding due to wave overtopping, fluvial flooding, combinations of tidal and fluvial flooding, surface water or ground water flood risk. The analysis appears to over-estimate the risk of tidal flooding at Carmarthen, due to a lack of tide level and extreme tide level data at this location. Along the SMP2 coastline the additional number of properties at risk is typically small (less than 4% for 1m future sea level rise), compared to the number of properties which are currently at risk, since the topography rises steeply from the existing flood plain, see Table J.3 and Figures J.2 and J.3. Table J.3: Number of residential and non-residential properties at risk from future sea level rise (1 in 1,000 year return period extreme tide event, excluding existing defences) Residential properties Excluding sea level 1m future sea level 2m future sea level rise rise rise 12,927 13,416 14,024 (489 or 3.8%) (1,097 or 8.5%) Non-residential properties Excluding sea level 1m future sea level 2m future sea level rise rise rise 2,592 2,686 2,767 (94 or 3.6%) (175 or 6.8%) (Figures in brackets indicate the increased number of properties which are at risk from flooding as a result of future sea level rise) J-12

19 Figure J.2: Number of residential properties which are at risk from flooding, including future sea level rise 1m and 2m (1 in 1,000 year return period extreme tide event, following failure of existing defences) Figure J.3: Number of non-residential properties which are at risk from flooding, including future sea level rise 1m and 2m (1 in 1,000 year return period extreme tide event, following failure of existing defences) J-13