West Rhyl Coastal Defence Scheme

Transcription

1 West Rhyl Coastal Defence Scheme Environmental Statement Non Technical Summary 11 October 2010 CH028/ES/NTS

2 THIS PAGE IS INTENTIONALLY BLANK Cascade Consulting

3 Client: Denbighshire County Council Title: West Rhyl Coastal Defence Scheme Environmental Statement: Non-Technical Summary Project No: CC312 Date of Issue: 11 October 2010 Status: Version No: 1.0 Produced By Authorised for Release By.. Alex Hampson Environmental Scientist Liz Baker Technical Director CONTACT DETAILS CASCADE CONSULTING Enterprise House Manchester Science Park Lloyd St North Manchester M15 6SE Tel: Fax:

4 THIS PAGE IS INTENTIONALLY BLANK Cascade Consulting

5 Non-Technical Summary [Volume 1 Main Text, is provided as a separate document] [Volume 2 Technical Appendices, is provided as a separate document] Contents 1.1 Introduction Scope of Assessment and Consultation Approach to Environmental Impact Assessment Planning Policy Context The Proposed Scheme Environmental Impacts Cumulative Effects Assessment Summary Contacts and Further Information LIST OF FIGURES Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Existing Site General Arrangement of Proposed Scheme and Surrounding Areas Land Ownership and Proposed Extent of Site Works Typically High Baseline Current Speeds within Foryd Harbour on a Spring Tide at HW -1h20m and HW +1h40m Environment Agency Flood Map (Existing) at and Around the Proposed Works and Existing Flood Defence Measures Predicted Extreme Flood Map with Scheme (2115 in 200 Year Tidal Flood) Noise Monitoring Locations Visual Impact Assessment from Key Views Cumulative Effects Assessment Scheme Locations in Relation to the Coastal Defence Works LIST OF TABLES Table 1 Environmental Issues Scoped In/Out LIST OF PLATES Plate 1 Plate 2 Plate 3 Plate 4 Plate 5 Plate 6 Plate 7 General View within Outer Harbour Damage at the Foot of the Training Wall Damage to the Training Wall Existing Revetment with Buried Toe Artistic Impression of Proposed Outer Harbour (not to scale) Artistic Impression of Proposed Inner Harbour (not to scale) Artistic Impression of Proposed Phase 1 & 2 Intersection with Phase 3 shown in Background (not to scale) Cascade Consulting

6 THIS PAGE IS INTENTIONALLY BLANK Cascade Consulting

7 NON TECHNICAL SUMMARY 1.1 INTRODUCTION The Application Denbighshire County Council is seeking planning permission to undertake coastal defence works on the seafront in Rhyl, North Wales. Substantial areas of the town are below high tide level, so when waves overtop the existing seawall or the defences are breached, there is a major risk of flooding. The existing coastal defences are in need of upgrading to improve protection of the town against flooding, and Denbighshire County Council therefore proposes to provide a new harbour wall, training wall and revetment to meet this requirement. The existing site, where the works would be located, is shown in Figure 1. Figure 1 Existing Site About This Document The purpose of this Non-Technical Summary is to present an overview, in nontechnical language, of the main findings of the Environmental Impact Assessment reported in the Environmental Statement. It includes a description of the proposed 1 Google Earth, Data SIO, NOAA, US Navy, NGA, GEBCO 2010 Europa Technologies, Image 2010 Bluesky, Infoterra Ltd & COWI A/S, 2010 Tele Atlas Cascade Consulting 1

8 scheme, how the construction and operation is expected to affect people and the environment and proposes ways to eliminate, mitigate or reduce any significant adverse effects on the environment. It also includes a description of any residual impacts that are expected to remain after mitigation. The Environmental Statement has been prepared in accordance with the Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 1999 (as amended) and will be presented in support of the planning application to Denbighshire County Council and Conwy County Borough Council. The application will be subsequently reviewed and determined by Denbighshire County Council Development Control in consultation with Conwy County Borough Council. Any significant residual impacts identified in the Environmental Statement will be taken into consideration by the councils when they decide whether to grant planning consent for the proposed works. Other consents are also being sought from Welsh Assembly Government Marine Consents Unit and the Environment Agency Wales for aspects of the works but they do not form part of the Environmental Statement The Need for the Rhyl Coastal Defence Works Previous studies have indicated the spatial extent of flooding from the sea in the absence of the defences along the coastline. There are particularly high risks to the western part of Rhyl and along the line of the A548 between West Rhyl and Prestatyn. There is, therefore, substantial risk to assets in these areas, including residential and commercial properties. The existing coastal defences along the Rhyl coastline comprise a sea wall and training wall. However, if these defences are breached, or waves overtop the structures, there is the potential for significant flooding to occur. The sea wall across the whole of the Rhyl frontage is susceptible to severe overtopping and studies have shown that the length between Foryd Harbour and Drift Park to the east requires upgrading in order to improve protection of Rhyl against flooding. In addition, there is an urgent need to upgrade the training wall which trains the River Clwyd out to sea away from Rhyl Promenade frontage. Plates 1 to 4 show the general study area, including examples of the existing condition of the coastal defences. Cascade Consulting 2

9 Plate 1 General View within Outer Harbour Plate 3 Damage to the Training Wall Plate 2 Damage at the Foot of the Training Wall Plate 4 Existing Revetment with Buried Toe Cascade Consulting 3

10 The West Rhyl Coastal Defence Scheme aims to provide relief from both erosion and overtopping of the existing sea defences in order to provide greater protection to properties inland of the promenade wall at Foryd Harbour and east of the Ocean Plaza site. The scheme design has been undertaken using both the Department for Environment Food and Rural Affairs/Welsh Assembly Government guidance 2 which accounts for an extreme storm event (one estimated to occur on average once in 200 years) and allowing for 100 years of sea level rise 3. The proposed scheme lies within the regeneration area of Foryd Harbour where developments are being planned, potentially including a new hotel and supermarket on the Ocean Plaza site. The scheme also fits well within the strategy for the Rhyl frontage, where improvements have already been undertaken at Drift Park Alternatives Options The Environmental Impact Assessment Regulations require the main alternatives to the proposed scheme that have been studied, and the principal reasons for their rejection, to be outlined in the Environmental Statement. Alternative locations were not considered because the proposed scheme involves the improvement of existing infrastructure. However, a number of alternative options and designs were evaluated to address the objective of the scheme, which is to reduce flood risk at Rhyl taking into account climate change impacts of predicted sea level rise and the consequent increased risk of wave overtopping at Rhyl frontage. These alternative options have been described and discussed in the Environmental Statement and are summarised below. Do Nothing (Option 1) - no works, including maintenance would be undertaken, which would result in an ever-increasing risk of both flooding to Rhyl and deterioration of the coastal defences. Do Minimum (Option 2) - this is the approach currently being taken by Denbighshire County Council in attempting to maintain the existing defences against flood and erosion events. However, this option does not address the risk of overtopping along various sections of the harbour wall. Improve (Options 3 7) a previous report originally considered five improvement options with a view to achieving up to an average 100 year life of the coastal defences. All of the options included upgrading of the training wall, works to 2 Flood and Coastal Defence Project Appraisal Guidance (FCDPAG3) Economic Appraisal 3 The overall coastal defence scheme has been designed for a 1 in 200 year return period, with an allowance for 100 years increase in sea level, with the exception of the training wall. The training wall has been designed in line with current sea-level rise, although provision has been made within the design to allow for future improvements based on future sea level rise prediction to 2115 Cascade Consulting 4

11 the sea wall to the east of the training wall up to Drift Park, and various proposals for improvement to the harbour wall from Foryd Harbour to the intersection with the training wall. Improve (Option 8) - another improvement option was later suggested by the Rhyl Foryd Harbour Forum comprising the provision of rock tipping out from the harbour wall and current inshore groyne on Horton s Nose Option Selection and Preferred Option The advantages and disadvantages of each option were reviewed, taking into account the ability of the works to fulfil the objectives of the West Rhyl Coastal Defence Scheme; construction and operational costs; engineering practicability; and potential environmental impacts on transport, access, recreation, landscape and visual amenity during construction. On balance, Option 5 was identified as the preferred solution for providing the required level of flood protection while minimising the impacts of the works. In comparison to the other options, it had a moderate capital cost and low maintenance cost. 1.2 SCOPE OF ASSESSMENT AND CONSULTATION Consultation The scope of the Environmental Impact Assessment was established through consultation with statutory bodies and interested parties, which is a key element of assessing the environmental impacts of a scheme. Consultation allows a full understanding of the baseline environment and potential nature of impacts. The consultation programme included the preparation and submission of a Scoping Report and Scoping Opinion request to Denbighshire County Council in December 2009 together with a number of meetings with stakeholder groups to discuss the proposals. The Scoping Report was copied to the following consultees: Cadw Centre for Environment Fisheries and Agriculture Science Clwyd and Conwy Rivers Trust Clwyd-Powys Archaeological Trust Conwy County Borough Council Countryside Council for Wales Crown Estates Denbighshire County Council Dwr Cymru Welsh Water Environment Agency Wales Cascade Consulting 5

12 Maritime and Coastguard Agency Marine and Fisheries Agency North Wales Wildlife Trust Rhyl and St Aphans Angling Association Rhyl Charter Skippers Association Rhyl Environmental Association Rhyl Fisherman s Association Rhyl Foryd Harbour Forum Rhyl Town Council Rhyl Water Ski Club Rhyl Yacht Club RNLI (Rhyl Station) Welsh Assembly Government Marine Consents Unit Welsh Yachting Association Scope of Assessment As a result of the scoping and consultation process, key issues for the Environmental Impact Assessment were identified as shown in Table 1. This table identifies construction and operational phase issues that have been scoped into the Environmental Impact Assessment and those which have been scoped out. Table 1 Environmental Issues Scoped In/Out Topic Hydrodynamics Sediment Transport Flood Risk Water and Sediment Quality Flora and Fauna Key Environmental Issues During Construction Impact of sheet piling and rock armour placement works Mobilisation of sediments caused by works Potential for increased temporary risk during works to existing flood defences Potential for increased turbidity, reduction in dissolved oxygen and release of contaminants Potential to affect designated sites from impacts on water quality, noise and disturbance Potential impact of disturbance to terrestrial ecology, birds and otters Potential impact of sediment re-suspension and mobilisation of contaminants to aquatic ecology Potential impact of piling upon aquatic ecology Potential delays or disruption to fish migration Potential for adverse effects on aquatic ecology as a result of accidental pollution During Operation Potential for increased flow velocities, altered flow directions and changes to water level caused by scheme modifying channel Potential for increased size of training wall to interrupt east west long-shore sediment drift Benefit by reducing coastal flood risk Potential impact to dilution/dispersion of point and diffuse sources of faecal pollution Potential for modification to sediment transport systems to impact upon local protected sites Potential for modification of the channel to cause erosion of Horton s Nose Potential for modification of the flow regime to impact upon migratory fish species Potential impact on bivalve populations from modification of sediment transport within the Clwyd Estuary Air Quality Potential for dust to impact air quality Scoped out as completed Cascade Consulting 6

13 Topic Noise and Vibration Transport Navigation Landscape and Visual Amenity Heritage Human Waste Management Sustainability Key Environmental Issues During Construction Potential for construction plant and HGV emissions to impact air quality Potential for noise and vibration from construction works and traffic to cause nuisance to local noise sensitive receptors Potential for noise impact from construction compound Increased pressure on local road network due to HGV movements required to deliver materials and plant Increased pressure on local road network due to construction workforce traffic Disruption to cycle routes Impact of in channel construction works on marine users Increase in traffic due to HGV deliveries affecting views from properties Large construction plant such as cranes impacting upon sea views during construction of training wall and stepped revetment Piling works and rock armour placement affecting in harbour visual amenity Storage of materials on the foreshore affecting sea views Erection of construction compound and site office affecting landscape Lighting required for night time working Potential impact on local submerged archaeology and the City of Ottawa wreck Potential impact on local archaeology and the built environment in general Impact of the demolition of the existing landing platform for chartered angling industry Scoped out as waste issues during construction will be resolved through Site Waste Management Plan to be produced postapplication Scoped out as locally sourced materials will be used where possible in construction During Operation infrastructure will not affect air quality Scoped out as completed infrastructure will not generate noise or vibration Scoped out as completed infrastructure will not generate traffic or affect transport routes Impacts of the change in profile of the training wall on marine users Impacts of the change in profile and alignment of the harbour wall on marine users Changes to flow conditions within the channel and the sediment transport regime Potential for the scheme to affect the character of the townscape, seascape and landscape Potential impacts on the setting or remains of built heritage or archaeological features Scoped out as landing platform will be replaced after construction Impacts on the wider social or economic environment have been scoped out Scoped out as once built, the proposed scheme will not generate additional waste Scoped out Cascade Consulting 7

14 1.3 APPROACH TO ENVIRONMENTAL IMPACT ASSESSMENT General Assessment Approach Scoping and consultation with Denbighshire County Council, Conwy County Borough Council and a number of other consultees comprising statutory organisations and key stakeholders identified the key issues to be covered by the Environmental Impact Assessment. The existing environment at the site of the proposed scheme has been fully assessed as part of the Environmental Impact Assessment. Baseline analysis included both desk-studies and baseline surveys. The likely significant environmental effects have been predicted for each relevant topic (e.g. flora and fauna, water and sediment quality, heritage) through the comparison of baseline conditions (i.e. without development) with conditions that would result through the construction and operation of the proposed scheme. Potentially sensitive receptors, including local residents and businesses; the Clwyd Estuary; areas with special conservation status; and the wider community were also identified during the scoping process. Significant effects have been reported in the Environmental Statement. Mitigation measures to avoid, reduce or remedy any adverse impacts have been identified and incorporated into the scheme design and construction methods where appropriate. The significance of residual environmental impacts, i.e. those impacts that remain following the implementation of any mitigation measures, has been determined by reference to impact criteria for each assessment topic. These criteria classify impacts according to whether they are major, moderate, minor or negligible in magnitude, and whether they are considered to be adverse, neutral or beneficial in terms of their effect. Impacts identified as major or moderate adverse or beneficial are regarded as significant in terms of planning considerations. 1.4 PLANNING POLICY CONTEXT National Guidance Planning Policy Wales and Technical Advice Notes set out the Welsh Assembly Government s national policies on different aspects of land use planning. The most recent issue which has been taken into consideration during the Environmental Impact Assessment of the proposed coastal defence scheme is Planning Policy Wales Cascade Consulting 8

15 Edition 3 July The extent to which the proposed scheme complies with these policies, and those discussed below, can be found in a separate Planning Statement that has been submitted with the planning application Regional Guidance Shoreline Management Plans set out objectives for the management of coastlines. The Rhyl coastline falls under the Liverpool Bay Shoreline Management Plan sub-cell 11a Management Unit 4 5. The objective set out for the Rhyl coastline is hold the line or maintain the current position in terms of defending the coastal area from flooding. This requires improvements to the coastal defences at Rhyl, as proposed by this scheme Local Guidance The Denbighshire Unitary Development Plan , Colwyn Borough Local Plan 7 and Clwyd Structure Plan: Second Alteration 8 provide the most relevant local planning policy guidance and the proposed coastal defence scheme broadly complies with the policies in these plans. 1.5 THE PROPOSED SCHEME Scheme Description The proposed scheme will include the following three main elements: Phase 1 Upgrading of the River Clwyd training wall, which trains the river flows out to sea away from the Rhyl Promenade frontage. The existing training wall would be encased with a rock armour profiled structure. On the western side of the training wall, five navigation markers will be installed to aide navigation and at the training wall/harbour wall intersection, two new linked static access platforms will be incorporated to replace the existing informal landing platform, currently used by harbour users. Phase 2 Improvement to the existing sea wall, from Foryd Harbour Bridge to the intersection with the training wall, subdivided by the proposed Foryd Harbour Sustainable Transport Bridge 9 as the inner and outer harbour. This will comprise the installation of sheet piles and placement of rock armour at varying slopes to address overtopping. The existing concrete sea wall will be removed and replaced with a wave return wall. At the request of the Rhyl Foryd Harbour Forum, a pontoon is 4 Planning Policy Wales Edition 3 (July 2010) 5 Shoreline Management Plan SMP 1 (Liverpool Bay Shoreline Management Partnership, 1999) 6 Denbighshire Unitary Development Plan Colwyn Borough Local Plan, Adopted 31 March Clwyd Structure Plan: Second Alteration (Conwy version), Adopted 31 March The Foryd Harbour Sustainable Transport Bridge Scheme will be subject to a separate planning application Cascade Consulting 9

16 proposed to be installed immediately upstream of the inner/outer harbour wall intersection. Phase 3 Precast stepped concrete revetment and wave wall to the east of the training wall at the intersection with the existing seawall between Sydenham Avenue and John Street. This will create a promenade facility with soft landscaping and car parking facilities behind the flood wall, although this element of the scheme will be subject to further detailed design and agreement with Denbighshire County Council. In addition to the main three elements of the scheme outlined above, a series of additional works are proposed including: improvements to the footpath and cycle path behind the sea wall themed decorations on the landward face of the wave return wall highways drainage improvements provision of hand rails along the promenade, where necessary temporary removal and re-installation of the promenade lighting along the harbour wall following completion of the works temporary relocation of the bus stop located between Sydenham Avenue and Quay Street during Phase 1 and 2 of the works and provision of new facility at a suitable location to be agreed with the Local Highways Authority. A layout plan of the proposed coastal defence works is shown in Figure 2. Artistic impressions of the proposed scheme are set out in Plates 5 to 7. The extent of land required for the proposed permanent works plus any temporary working areas is illustrated by the red line boundary in Figure 3. This shows that the permanent works fall within Denbighshire County Council s land ownership, with the exception of the northern end of the training wall which falls within land owned by the Crown Estates and a small section of the training wall which lies within Conwy County Borough Council s land ownership. The temporary construction compound will be located within a site owned by Scarborough Development Group. Cascade Consulting 10

17 Figure 2

18 THIS PAGE IS INTENTIONALLY BLANK

19

20 THIS PAGE IS INTENTIONALLY BLANK

21 Plate 5 Artistic Impression of Proposed Outer Harbour (not to scale) Plate 6 Artistic Impression of Proposed Inner Harbour (not to scale) Plate 7 Artistic Impression of Proposed Phase 1 & 2 Intersection with Phase 3 shown in Background (not to scale) Cascade Consulting 15

22 1.5.2 Construction The overall contract duration is likely to be 30 months, which includes some preliminary demolition works and construction of all three phases. Although split into phases, the construction of the training wall and harbour wall (Phases 1 and 2) is expected to be undertaken on several sections at the same time, as the work has to be undertaken when most of the estuary is dry, at low tide. This will maximise the working window within the tidal sequence, i.e. during the lowest tides (springs), a team will construct the training wall extremity working landwards, whilst another team will progress the works from the landward end during the neap tides, when water levels at low tide are slightly higher. Due to the need to work during low tide, some night-time working will be required. The duration of Phases 1 and 2, including site establishment, is likely to be 18 months from January 2011 to July Casting of the concrete stepped revetment units will be undertaken at a suitable location off site, while the Phase 1 and 2 works are ongoing. Phase 3 will then commence on site following completion of Phases 1 and 2 in July 2012, with an estimated completion date of mid The construction of each structure would be largely shore-based; no work will be undertaken from boats or barges. Tracked excavators will work on the foreshore at low tide to facilitate construction at the toe of the training wall. When access to the foreshore is required during the construction programme, public access to sections of the promenade would be restricted. Best practice guidelines for working in coastal waters would be adhered to with no fuelling or vehicle maintenance to be carried out on the foreshore or in the Clwyd Estuary channel. It has been agreed in principle with Scarborough Development Group, who own the former fairground site at Ocean Plaza, that an area of land within their ownership will be made available for a contractor s compound/laydown area for materials and plant. This area provides a direct route off the main B5118 West Parade and directly onto the foreshore east of Sydenham Avenue. The compound may also be used to site a concrete batching plant if this is used by the contractor in preference to importing readymix concrete. Details of the construction methods and programme are provided in the Environmental Statement, including the following: demolition and construction plan and programme description of works materials and resource use hours of work Cascade Consulting 16

23 traffic generation and routing Environmental Management Plan A Framework Environmental Management Plan has been prepared which presents an overview of the mitigation and environmental protection measures set out within the Environmental Statement. The mitigation measures are required to minimise environmental impacts within the development site and the surrounding area during the demolition and construction phase of the proposed development. The Framework Environmental Management Plan provides an outline of how construction activities will be managed, including designation of responsibilities for implementing the mitigation measures, monitoring their effectiveness, and taking remedial action in the event that an unacceptable impact is identified. It provides a basis for the detailed Environmental Management Plan which is normally provided post-consent as a requirement of planning conditions. The Environmental Management Plan will be a live document which will be updated as required throughout the course of the development programme. Prior to commencement of demolition and construction activities, the Environmental Management Plan will be reviewed and updated by Denbigshire County Council s appointed principle contractor subject to discussions with development control officers from Denbighshire County Council and Conwy County Borough Council, as required. 1.6 ENVIRONMENTAL IMPACTS Overview This section provides a summary of the significant residual impacts on receptors that are likely to arise from the proposed scheme. Hydrodynamic and Sediment Regimes The hydrodynamic regime near to the proposed scheme was investigated to assess what effects the scheme would have on flow speeds, flow directions and water levels within the estuary and the wider coastal environment. The Clwyd Estuary typically has high flow speeds during the incoming flood and retreating ebb tide in the area around the inner and outer harbour wall, as shown in Figure 4. The local sediment regime, including processes such as deposition, erosion and movement of sand along the coast, was also investigated. These investigations are critical since the hydrodynamic and sediment regimes affect other key receptors such as ecology and navigation. Cascade Consulting 17

24 Temporary Impacts Following mitigation, the hydrodynamic and sediment regimes investigations found that there were no significant impacts during construction as a result of the proposed scheme. Minor adverse residual impacts during construction would be limited to sediment release from disruption of the channel bed or beach as a result of activities such as excavation, piling and vehicle movements. Long-term Impacts The hydrodynamic and sediment regime investigations found that there were no significant operational impacts as a result of the proposed scheme. Residual impacts during operation include a minor adverse impact on the sediment regime, 100m east of the training wall and fronting the stepped revetment; a temporary minor neutral impact to sediment regime in the channel fronting West Parade; a potential, limited increase in the erosion of Horton s Nose (seen as partly beneficial as the accretion of this feature has been a hindrance to harbour users), a minor neutral increase in flows at Horton s Nose and in the channel fronting West Parade and a minor adverse reduction in wind blown sand reaching the area approximately 250m east of the training wall. Flood Risk/Flood Consequence Assessment West Rhyl is in a low lying area that is at risk from flooding from both the sea and the adjacent estuary. Up to 2,500 existing residential/commercial properties are considered to be at risk of flooding from an extreme 1 in 200 year tidal flooding event (i.e. that would occur on average once in 200 years) overtopping the existing coastal defences. The extent of existing flood risk in the area around the works is illustrated in Figure 5. This shows that with existing defences during the extreme 1 in 200 year tidal flood, flooding to a depth of up to 3m could occur in Rhyl, which would be potentially catastrophic. The proposed coastal defence scheme has been designed so that the risk to people and properties from tidal flooding is substantially reduced. Temporary Impacts Negligible residual flood risk impacts are predicted during the construction phase of the proposed coastal defence scheme. Cascade Consulting 18

25 FIGURE 4

26 THIS PAGE IS INTENTIONALLY BLANK

27 Flooding from rivers or sea without defences (EA data) Extent of extreme flooding (EA data) Existing flood defences Area benefiting from flood defences (EA data) Main River (EA data) Approximate footprint of scheme Environment Agency flood map (existing) at and around the proposed works and existing flood defence measures Figure 5

28 THIS PAGE IS INTENTIONALLY BLANK

29 Long-term Impacts The proposed scheme would lead to a significant reduction in overtopping of the coastal defences, which would lead to a significant reduction in flood risk, in terms of extent and depths of flooding. Flooding that could occur with the proposed defences in 2115, were the 1 in 200 year extreme tidal flood to occur, is illustrated in Figure 6. The area and extent of flooding is substantially less than that which would occur with existing defences. Flooding depths would be no greater than 0.6m (compared to 3m with the existing scheme) and the number of properties affected by the flooding would also be reduced. As such, the scheme is considered to have a permanent major beneficial operational impact with regard to flood risk. Water and Sediment Quality Temporary Impacts Following the implementation of mitigation measures, including adoption of good working practices, no significant residual water and sediment quality impacts are predicted during the construction phase of the proposed coastal defence scheme. Long-term Impacts No significant residual water and sediment quality impacts are predicted during the operational phase of the proposed coastal defence scheme. Minor beneficial residual impacts from enhanced dilution of Clwyd Estuary waters as a result of the training wall improvements may slightly improve the quality of the local bathing waters. Flora and Fauna Temporary Impacts Construction activities may result in temporary disturbance to birds using the Clwyd Estuary and surrounding habitats, although when not directly threatened birds are known to habituate to disturbance. The impacts on bird populations have been assessed as minor adverse and temporary. Use of good construction practice will minimise sediment resuspension and noise related disturbance of resident and migratory fish populations. In-channel works will be undertaken during low tide. Where in-channel works cannot reasonably be avoided during peak migratory periods, appropriate breaks in piling activities will provide sufficient time for migratory fish to pass the areas of works. Residual impacts are considered to be minor adverse and temporary. Cascade Consulting 23

30 Other impacts on ecological receptors, including European designated sites 10, from construction activities are considered negligible. Long-term Impacts The proposed scheme will result in limited land take, with the majority of works replacing or improving existing man-made features and therefore the potential impact magnitude of the scheme is considered to be low. Where habitat will be lost to the scheme due to construction of the stepped revetment, the land is considered to be of low ecological value. Localised hydrodynamic changes as a result of the scheme may cause low level of disturbance to non-statutory designated sites, namely the Clwyd Estuary and Floodplain, and Horton s Nose Wildlife Sites. These impacts are considered to be minor adverse. There are no significant residual ecological impacts predicted to result from operation of the scheme. Air Quality Temporary Impacts The proposed works will include a number of specific dust-generating activities as part of the demolition and construction activity. In the absence of mitigation, temporary and localised dust impacts could affect sensitive receptors, including residential properties, up to 500m from the site. Where appropriate, dust generating activities will be undertaken off-site, however, where this is not possible these activities will be located away from the site boundary and sensitive receptors. Good construction practice will be adopted to further reduce dust emissions. With implementation of these mitigation measures, the impacts on air quality will be reduced. The receptors that may still be affected include the residential properties on Sydenham Avenue, which lie within 25m of the contactor s compound. These residual impacts are considered to be temporary and of minor adverse significance. The predicted impacts due to vehicle emissions from road vehicles associated with the scheme are not considered significant. 10 A separate report to support a Habitats Regulations Assessment has been prepared and submitted to the Countryside Council for Wales Cascade Consulting 24

31 Predicted floodpath Extreme flood map (with proposed scheme) Stepped Revetment Predicted extreme flood map with scheme ( in 200 year tidal flood) Figure 6

32 THIS PAGE IS INTENTIONALLY BLANK

33 Long Term Impacts No local air quality or dust impacts are anticipated during the operational phase of the proposed coastal defence scheme. Noise and Vibration Temporary Impacts Noise sensitive receptors include residential properties and hotels along Ford Road (adjacent to Sunnyvale Holiday Campsite), West Parade, Sydenham Avenue and surrounding roads, and Sunnyvale Holiday Campsite (Figure 7). Construction noise impacts were assessed as worst case scenarios and took into consideration the combined impact of various construction activities taking place concurrently. Mitigation measures, including use of best practice guidance; restricting piling activities to daytime only; use of hydraulic or vibration rather than percussive piling techniques; working in areas away from sensitive receptors during night-time working; and the erection of hoardings around the construction compound will reduce noise and vibration impacts. The impact on the individual receptors will not be for the full duration of the construction period, as the works would be carried out in different parts of the site at different times. The residual noise impacts have been assessed as temporary minor/moderate adverse. There will be no significant residual vibration impacts from proposed piling activity. Long Term Impacts No noise or vibration impacts are anticipated during the operational phase of the proposed coastal defence scheme. Transport Temporary Impacts Transport of construction materials to the site will necessitate a large number of vehicle movements to and from the site. Deliveries of materials will be carefully managed to minimise disruption to the local road network. A number of measures will be implemented, including: restricting access to the site by HGVs to with approximately 39 HGV deliveries per day within this restricted window using a dedicated access route for major deliveries, including the rock armour and sheet piles on 20 tonne vehicles. The preferred route, which has been agreed with Denbighshire County Council, brings traffic from the A55 across the Foryd Harbour Bridge via the A525, A547 and A548, thereby limiting the number of Cascade Consulting 27

34 roads in the local network likely to be affected by the construction works a contractor s compound located between Quay Street and Sydenham Avenue will be designated for the storage of material rock will be offloaded by road delivery vehicles in the contractor s compound and transferred to suitable 4x4 or 6x6 wheel drive dump trucks for delivery to the foreshore. The implementation of the proposed mitigation measures will reduce the impact of the HGV traffic to a temporary moderate adverse significance. The impact of traffic generated by the construction workforce is considered to be of temporary minor adverse significance. The section of the B5118 West Parade between the roundabout adjacent to the Foryd Harbour Bridge and Quay Street will require temporary road closure limited to short periods during plant delivery and when piling is being undertaken from the promenade. Once appropriate diversions have been put in place, the impact has been assessed as being of temporary moderate adverse significance. Restricted pedestrian access to the promenade will be for short periods during construction of all phases. As such, the impact is considered to be of minor adverse significance. Long Term Impacts No transport impacts will arise during the operational phase of the proposed coastal defence scheme. Cascade Consulting 28

35 Figure 7

36 THIS PAGE IS INTENTIONALLY BLANK

37 Landscape and Visual Amenity Temporary Impacts Construction activities will result in short term landscape impacts on Rhyl Promenade and the intertidal zone and beach. The phased approach to the construction may assist in limiting impact to certain areas during certain phases, however, the potential landscape impacts cannot be completely avoided. Therefore, the residual impact on landscape during construction will be of moderate adverse significance. The construction phase will result in temporary, significant adverse impacts on visual receptors in the immediate vicinity of the construction works and traffic routes (identified as key view numbers 2, 3, 4, 5, 6, 7, 9, 10, 11 and 12 on Figure 8). Hoardings around the construction site and the phasing of works will minimise impacts to some receptors, however, mitigation measures will have a limited effect on the level of impacts identified due to the scale of the proposals and the duration of the construction period, albeit phased. Therefore, the residual impacts on visual amenity will be of major/moderate adverse significance. Long Term Impacts Following construction, the overall scheme is considered to have moderate beneficial impact on landscape features owing to the terrestrial and seaward enhancements to Rhyl seafront. No significant residual visual impacts have been identified at the operational stage. Heritage Temporary Impacts The potential impacts of the scheme on archaeological sites and built heritage include physical impacts, and visual impacts upon the setting, of heritage assets during construction. The excavation operations associated with the coastal defences will not impact upon any known archaeological deposits and are therefore of negligible significance. By implementing mitigation measures to minimise the effects of vibration from piling, residual impacts on the City of Ottawa will also be negligible. However, any potential physical impacts to undiscovered palaeoenvironmental remains are unknown. An appropriately qualified archaeologist will monitor the removal of material from the areas where excavation is taking place to record any palaeoenvironmental deposits or archaeological remains should they be identified. The impacts upon the setting of the the wreck of the City of Ottawa and the listed Foryd Harbour Bridge will be temporary and are considered to be of minor adverse Cascade Consulting 31

38 significance. Long Term Impacts The potential impacts of the operational phase of the scheme on archaeological sites and built heritage include visual impacts upon the setting of features. There will be impacts of minor adverse significance on the setting of the City of Ottawa wreck and Foryd Harbour Bridge as a result of the scheme. Navigation Temporary Impacts During construction, vessel navigation may be affected by construction works within the estuary, changes in flow, and a potential increased risk of collision. Mitigation measures which will be implemented to reduce or avoid any impacts include: working in the channel only to be carried out at low tide when the channel is not navigable provision of temporary navigation markers during the works to guide mariners away from the working area the working methods of placing rather than dropping rock armour will reduce the likelihood of material being misplaced, and any material on the channel bed outside the works footprint will be removed before the next tide to avoid hazards to vessels any lighting required will be specified and positioned appropriately to avoid imitating navigation aids and to reduce visual impact during night time working regular liaison with the harbour and river users will be carried out so that they are fully aware of the upcoming activities to ensure that they can make suitable alternative arrangements. After the implementation of mitigation, the potential risk of collision or obstruction during construction of the training wall and harbour wall has been assessed as a temporary minor adverse residual impact. The impact of losing the informal landing platform on the training wall has been assessed as a temporary moderate adverse impact. The existing floating pontoon on the west quay of the harbour will remain accessible to all harbour users, however, this facility is accessible for a shorter time than the informal landing platform due to tidal restrictions. Cascade Consulting 32

39 Figure 8

40 THIS PAGE IS INTENTIONALLY BLANK

41 Long Term Impacts Following implementation of mitigation measures, including provision of a Notice to Mariners or similar at the end of the works, to provide an overview of all the changes made, no significant adverse impacts to navigation are anticipated. The proposed scheme, once in operation, will improve safety for vessel users through the increased visibility of the training wall. In addition, the provision of the new static landing jetties on the training wall and additional pontoon on the inner harbour wall will greatly improve access to the Foryd Harbour in the long term and is considered to be of minor beneficial significance. Human Temporary Impacts The scheme has been designed to compensate for the loss of the informal landing platform on the training wall (which is used by charter vessels to board paying passengers over a wider tidal range and thus increases their potential trip duration and revenue) by including two new linked static landing jetties on the harbour wall. However, these will not be accessible until after construction is complete. During construction, vessels can use the existing floating pontoon on the western harbour wall, although this has a slightly restricted tidal range compared to the training wall. The residual impact is, therefore, considered to be of temporary moderate adverse significance. Long Term Impacts No long term impacts to chartered angling vessels activities are anticipated during the operational phase of the proposed coastal defence scheme. 1.7 CUMULATIVE EFFECTS ASSESSMENT In accordance with Schedule 4 of the Environmental Impact Assessment Regulations 11, the Environmental Statement includes consideration of cumulative effects. These are impacts that result from incremental changes caused by other past, present or reasonably foreseeable actions together with the proposed scheme. The combined effects of several development schemes may, on an individual basis, be insignificant but cumulatively may have a significant effect. The Environmental Statement has thus considered the impacts of the proposed scheme in combination with the potential environmental effects of other identified proposed developments taking place in the vicinity of the coastal defence works. The schemes which may run concurrently with the proposed coastal defence scheme 11 Town and Country Planning (Environmental Impact Assessment) (England and Wales) Regulations 1999 (as amended) Cascade Consulting 35

42 include: Reconfiguration of Moorings within Foryd Harbour Removal of the City of Ottawa wreck. Foryd Harbour Sustainable Transport Bridge The locations of these schemes in relation to the coastal defence works is shown in Figure 9. The cumulative effects assessment concluded that in general, residual cumulative effects will be similar to those residual impacts arising from the coastal defence scheme alone, resulting in no net change. However, some potential cumulative effects have been identified, arising mainly during the construction phase of the West Rhyl Coastal Defence Scheme when other schemes are being progressed within the harbour at the same time. These include adverse impacts of noise, changes to water levels and flows, and increased sediment disturbance and turbidity in the estuary. Combinations of these impacts could affect local residents, harbour users and the ecological value of the study area. The majority of cumulative impacts for the construction phase are associated with construction of the Foryd Harbour Sustainable Transport Bridge. Depending on when construction contracts are let for each of the proposed schemes and hence when the resulting construction programmes are known, it will be necessary to review the need for coordinated mitigation measures and to update the Environmental Management Plan for the coastal defence works accordingly. As all agreed cumulative schemes are being promoted by Denbighshire County Council, effective co-ordination of construction programmes should be possible to mitigate cumulative impacts arising from the various construction activities. After construction, when the schemes are operational, the most significant cumulative impacts arise from the reduced navigable access to the channel as a result of the new inner harbour pontoon associated with the coastal defence scheme and the moorings reconfiguration scheme; and potential increased vessel collision risk due to the position of the proposed cycle bridge caisson and cantilever landing. Cascade Consulting 36

43 Figure 9

44 THIS PAGE IS INTENTIONALLY BLANK

45 1.8 SUMMARY Throughout the construction programme, temporary adverse impacts are anticipated especially in relation to traffic movements, construction noise, landscape and visual amenity, and impacts associated with the loss of amenity and navigational access in the harbour area. A Framework Environmental Management Plan has been prepared to ensure that the mitigation measures and monitoring described in the Environmental Statement are implemented and are effective in reducing impacts on sensitive receptors. Ongoing consultation with Denbighshire County Council and other consultees throughout the design process has benefited the overall design of the proposed scheme and minimised impacts on sensitive receptors wherever possible. The improvements brought by the West Rhyl Coastal Defence scheme will result in long term major beneficial impacts through reduced risk of flooding and hence a reduced risk to life, disruption to those living and working in Rhyl and the potential for damage to property. No significant long term adverse impacts have been identified. There will also be a long term beneficial impact on landscape and visual amenity, and improved navigational access and landing facilities within Foryd Harbour, which will be of benefit to the harbour users. The proposed scheme will have a positive impact on Rhyl and the beneficial impacts of the scheme are considered to outweigh the potential for negative impacts. 1.9 CONTACTS AND FURTHER INFORMATION This Environmental Statement is available for viewing by the public during normal office/opening hours at the Planning Departments of Denbighshire County Council and Conwy County Borough Council. The Environmental Statement is also available for viewing at Rhyl Library, Church Street, Rhyl, LL18 3AA. Comments on the planning application can be sent via to planning@denbighshire.gov.uk or alternatively by post to: Denbighshire County Council Development Control Caledfryn Smithfield Road Denbigh Denbighshire LL16 3RJ Cascade Consulting 39

46 Comments on the planning application can also be sent to Conwy County Borough Council by post to: Planning Office, Conwy County Borough Council Civic Offices, Colwyn Bay, LL29 8AR Additional electronic copies (CD or DVD) of the full Environmental Statement can be purchased from Denbighshire County Council, priced at 15 and a hard copy of the Environmental Statement can be purchased for 85. Free copies of the Non Technical Summary can be obtained by writing to Denbighshire County Council Development Control at the address above. Cascade Consulting 40