Site Allocations DPD Strategic Flood Risk Report
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Cornwall Local Plan: Site Allocations DPD Strategic Flood Risk Report Appendix 6 ARCHIVED EVIDENCE DOCUMENT Contents Appendix 6 – Exception Tests: Harbourside Car Park and Wherrytown, Penzance ........................................................................................... 3 SFRA2: Harbourside Car Park (Mixed Use) (PZ-M1) ............................... 6 SFRA2: Wherrytown (Mixed Use) (PZ-M3) .......................................... 14 ARCHIVED EVIDENCE DOCUMENT Appendix 6 – Exception Tests: Harbourside Car Park and Wherrytown, Penzance ARCHIVED EVIDENCE DOCUMENT 3 1. Introduction This appendix sets out the Exception Test to two sites as part of the Site Allocations DPD Strategic Flood Risk Assessment: Harbourside Car Park, Penzance; Wherrytown, Penzance. In addition, Appendix 7 sets out the Par Docks Sequential and Exception Test document. The Exception Test provides a method of managing flood risk while still allowing development to occur to meet wider sustainability objectives. The test is only applied for areas with substantial flood zone 2, 3a and 3b, where the sequential test was unable to identify appropriate alternative sites. The exception test for each site has been conducted at a strategic level for the Site Allocations document and is split into two parts as follows: Part (a) wider sustainability benefits Part (b) safe development The site profiles SFRA2 information, sequential test and Exception Test information should be made available to developers for masterplanning, applications and site specific flood risk assessments (FRA’s) to help ensure that they are able to satisfy the requirements for the Exception Test at the detailed design stages. 2. Sites Two of the sitesARCHIVED requiring the Exception Test are located in Penzance and one is located in Par. The Exception Test is set out for the two Penzance sites here; the Exception Test for Par Docks is set out in Appendix 7. 2.1 Harbourside Car Park, Penzance Part A: Wider Sustainability Benefits The 2 ha harbour side car park is located within the town centre area. It is proposed as a mixed use siteEVIDENCE for retail, leisure and employment with some residential on upper storeys. At the time of applying the exception test The Mounts Bay Shoreline Management study presents emerging options for strategic sea and flood defence solutions along Penzance waterfront which would apply to the Harbour Car Park. It is therefore assumed that the preferred solution will be incorporated and or influence any proposal. DOCUMENT The Sustainability Appraisal concluded the following: The site has good links to the strategic transport network, and is adjacent to the main line railway station and bus station in comparison to other sites around the urban area. Development of this mixed use allocation is to include retail and employment provision, so would improve access to and provision of additional services and facilities and therefore provide employment opportunities The established Vision and Objectives for Penzance which is set out within the strategy for the town include the following: To re-establish the status of Penzance’s Town Centre - strengthen, improve and extend the quality of the offer. To develop cohesive harbour and waterfront strategies for Penzance and Newlyn that enhance the harbour offer To become West Cornwall’s premiere tourist destination 4 Provide services and economic opportunities to support a wide hinterland Offer a range of equitable housing opportunities Support a thriving economy, based primarily on the marine, creative, leisure, retail and tourism industries; Address the predicted changes in sea conditions due to climate change. Penzance Town Centre like many faces a challenge in retaining its role as a vibrant retail, commercial centre for the community and town. Modern retailers struggle to find larger footprint stores within Cornwall’s historic town centres and often look at easier to develop out of town retail options which further threaten the health and vitality of centres. The location of the harbour car park, sitting within the town centre, on the waterfront therefore provides a unique regeneration opportunity for Penzance to provide space for retail and commercial uses, restaurants and cafes in an attractive waterside location with the potential to increase footfall and expenditure to the existing centre, by providing a focal point and destination for residents and visitors to the town. It is considered that due to a lack of suitable and available alternative locations, if the harbour car park was unable to be redeveloped for these regeneration uses then the risk would be further decline through reduced footfall and expenditure within the town from both residents and visitors. This context is recognised and supported by Penzance Town Council who are preparing a Neighbourhood Plan which focuses on improving the town centre and waterfront regeneration opportunities including a particular emphasis around regenerating the harbour side car park. There is also an aspiration to deliver a waterfront cycle route from Marazion to Newlyn, the delivery of whichARCHIVED can also support the delivery of improved flood resilience measures for the conurbation. In addition, the aspiration is to ensure this route has various ‘nodes’ which act as points from which people can access / depart the cycle network. The Harbour Car park is recognised as one of the most important sites as it will deliver part of the cycle route, plus act as the most important node, as it is adjacent to the transport interchange and the node can help attract people using the route into the town centre. Summary EVIDENCE The Harbourside car park is considered to be a key waterside regeneration opportunity site within the town, within the existing town centre area. It is considered that attractive waterfront uses will provide significant social and economic benefits to the town in line with the vision, objectives of the long term strategy for the Town, as identified in the Sustainability Appraisal. DOCUMENT Conclusions The above demonstrates that the wider sustainability benefits of developing the site significantly outweigh flood risk and the first part of the Exception test is passed. Part B Safe Development The second part of the Exception Test requires that development will be safe for its lifetime taking account of the vulnerability of its users, without increasing flood risk elsewhere and where possible reducing flood risk elsewhere. The Council considers that the information set out in the Harbour car park SFRA2 site profile demonstrates both strategic and specific considerations and solutions in relation to the site, including the emerging conclusions of the ‘Mounts Bay Shoreline Management Strategy’, to enable the site allocation to meet the requirements of part b of the exception test. However a site specific flood risk assessment will be required by applicants demonstrating that safe access routes to and from the site avoiding higher risk areas, and that development will be safe without increasing flood risk elsewhere and, where possible, will reduce flood risk 5 overall. The Council in consultation with the Environment Agency will assess any submissions against the above criteria. SFRA2: Harbourside Car Park (Mixed Use) (PZ-M1) ARCHIVED Flood ZoneEVIDENCE 2 The site is within Flood Zone 2 Flood Zone 3a The site is within Flood Zone 3a Flood Zone 3b Not within site Critical Drainage Areas Whole site falls within the Penzance Critical Drainage Area Shoreline Management Final flood outline @ 2055 with flood zone 3 affects Plan designation most of the site. DOCUMENTProjected coastline erosion @ 2055 (with prevention) seems not to affect the site. Projected coastline erosion @ 2055 (without prevention) does affect the northern part of the site and southern boundary. Epoch 1: Hold the Line Epoch 2: southern part of site: Hold the Line; northern part of site: Managed Realignment Epoch 3: southern part of site: Hold the Line; northern part of site: Managed Realignment Surface water flooding The site is entirely within a Critical Drainage Area. map Part of the northern portion of the site is likely to experience surface water flooding Hazard Maps Show significant risk across the site in relation to tidal flooding from wave overtopping, due to a combination of extreme high tides and extreme 6 weather events during a 1 in 200 years event, if the site remains undefended. During such events waves would overtop the harbour wall and move around the flat site area at a velocity and depth that would be an extreme hazard on around 60% of the site with a significant hazard on the remaining area, with water then receding back to the sea. Factoring in climate change the hazard map indicates that there would be extreme hazard on around 95% of the site. Hydrology assessment This site is currently a seafront car park for of site’s surface water Penzance. Any development of the site would have issues to provide future-proofed sea defences and flood storage. How to address flood risk issues as integral part of developing the site Issues to be addressed Site specific – Tidal flooding, surface water flooding, flood storage and coastal erosion. The shoreline management plan sets out that this flood risk 3 site will suffer from coastal erosion at its northern part and southern boundary of the site (without prevention) by 2055. It also recognises that hold the line at the southern boundary is appropriate due to its use. ARCHIVED The Hazard maps for the sites show that the specific hazard is from wave overtopping with subsequent water moving around and then receding back to the sea. The southern and eastern half of the site, undefended, shows an extreme hazard which would be dangerous for all in a 1 in 200 year event; this increases to cover almost all of the site area factoring in the climate change scenario.EVIDENCE Due to the nature of the hazard however there would be several hours warning in place before such significant events occurring. This hazard will need to be taken into account as integral to any detailed development of the site. PresentDOCUMENT ground level is around 3.5-3.8 m.OD.