Christchurch Bay and Harbour Forum Study
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Christchurch Bay and Harbour Flood and Coastal Erosion Risk Management Study Technical Annex 9: Strategic Environmental Assessment Prepared by Halcrow Group Ltd Christchurch Bay and Harbour Flood and Coastal Erosion Risk Management Study Technical Annex 9: Strategic Environmental Assessment Prepared by Halcrow Group Ltd Halcrow Maritime Burderop Park Swindon Wiltshire SN4 0QD Tel +44 (0)1793 812479 Fax +44 (0)1793 812089 www.halcrow.com Halcrow Maritime has prepared this report in accordance with the instructions of their client, Christchurch Coastal 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 2004 Christchurch Bay and Harbour Flood and Coastal Erosion Risk Management Study Technical Annex 9: Strategic Environmental Assessment Contents Amendment Record This report has been issued and amended as follows: Issue Revision Description Date Signed 1 0 Draft Contents Non-Technical Summary Introduction 1 Existing Environment 1 Planning and Legislation 5 Consultation 6 Environmental Objectives 6 1 Introduction 1 1.1 General 1 1.2 Approach 1 1.3 Objectives 2 1.4 Format 2 2 Existing Environment 3 2.1 Sources of Information 3 2.2 Location and Character 3 2.3 Geology and Geomorphology 3 2.4 Ecology and Nature Conservation 5 2.5 Landscape 21 2.6 Land Use and Population 22 2.7 Transport Network and Traffic 25 2.8 Water and Aquatic Environment 25 2.9 Contaminated Land 30 2.10 Tourism and Recreation 31 2.11 Fisheries 35 2.12 Archaeology and Cultural Heritage 36 2.13 Mineral Production 41 3 Planning and Legislation 47 3.1 Introduction 47 3.2 Review of Planning Policy 47 3.3 International Level 50 3.4 European Level 50 3.5 National Level 50 3.6 Regional Statutory Level 54 3.7 Regional Non-Statutory Level 58 3.8 Statutory Local Government Level 65 3.9 Local Non-Statutory Level 67 4 Consultation 71 5 Environmental Objectives 101 4 5.1 General Issues 101 5.2 Practicability, Sustainability and Economic Considerations 101 5.3 Nature Conservation Objectives 102 5.4 Cultural Heritage and Archaeological Objectives 103 6 Evaluation of Strategy Options 113 6.1 Introduction 113 6.2 Environmental Impacts and Opportunities Assessment 113 6.3 Options Considered 113 6.4 CHB1 Harbour Side of Mudeford Spit 114 6.5 CHB2 South Side of Christchurch Harbour 115 6.6 CHB3 Stanpit and Grimbury Marshes 117 6.7 CHB4 Mudeford Town Frontage 119 6.8 CHB5 Mudeford Quay 120 6.9 CBY1A & CBY1B Hengistbury Long Groyne to tip of Mudeford Sandbank 121 6.10 CBY2 Mudeford Sandbank to Chewton Bunny 124 6.11 CBY3 Chewton Bunny to start of defence at Barton on Sea 126 6.12 CBY4 Start of Defence at Barton on Sea to Barton Golf Course 128 6.13 CBY5 Barton Golf Course to Hordle Cliff 133 6.14 CBY6 Hordle Cliff to Hurst Spit 133 6.15 CBY7 Hurst Spit 135 7 Monitoring, Mitigation and Compensation 137 7.1 Environmental Monitoring 137 8 Conclusions and Recommendations 138 5 Non-Technical Summary Introduction Man-made changes, notably coastal defences, have had a significant impact on the present morphology of Christchurch Bay and Christchurch Harbour. This has resulted in erosion in other areas along the coast. In combination with the effects of rising sea levels, this has led to the possibility of existing flood defence failure. The aim of this Strategy is therefore to determine a more sustainable way to develop coastal and flood management options, which takes into account the natural environment of this coast as well as the need to sustain the human and built environment. The Strategic Environmental Assessment (SEA) Report is an integral part of the Strategy. The preliminary stage of the SEA is to prepare a baseline and objectives, of which this is a non-technical summary. The baseline: details the existing environmental conditions present within the Strategy study area (Figure 1); lists the key concerns of stakeholders; and defines environmental objectives for each component of the environment. The next stage in the Christchurch Bay and Harbour Strategy is to develop a long list of strategic options. These will be assessed by the Project Team and Steering Group in terms of their technical feasibility, environmental acceptability, economic viability and consequences in order to develop a short list of site strategic options. The short list of options will be issued to all consultees for comment and appraised against the objectives identified in the SEA, as well as for their technical and economic viability. Existing Environment The strategy study area is situated on the south coast of England, encompassing approx 16km of frontage within the counties of Dorset and Hampshire. The boundaries of the Christchurch Bay study area is delineated by Hengistbury Head long groyne to the west and Hurst Spit to the east. Hengistbury Head provides protection to Christchurch Harbour and the town of Christchurch that lies along its northern boundary. The coastline of the bay consists of eroding clay cliffs backed by a combination of settlements and agricultural land. Geology, Palaeontology and Geomorphology The geology of the area predominantly comprises sands, clays and marls of the Headon and Barton beds. The cliffs between Highcliffe and Milford on Sea are of international significance for geological conservation. Important sites include the cliffs between Highcliffe and Barton on Sea, the coastal section from Friars Cliff to Milford on Sea and the Hordle Cliff. There are a number of fossil rich cliffs within the study area. There are conflicts between the need to maintain geological exposures for conservation and study and the wish to prevent cliff recession to protect property by constructing and maintaining defences. The coastline of Christchurch Bay has undergone significant erosion. Hengistbury Head, Mudeford Spit and Hurst Spit all play a key role in the overall morphology of the Bay. In their absence it is likely that the coast from Durlston Head to Hurst Spit would evolve into a single bay and erosion of the cliffs would increase from wave attack. Ecology and Nature Conservation Significant features of nature conservation importance in the Bay include coastal sand dunes, saltmarsh, vegetated shingle, earth heritage, sublittoral rock, maritime cliff and slopes, reedbeds and saline lagoons. The coastline of the Bay is composed of a suite of habitats, including terrestrial, semi-aquatic, freshwater/mildly brackish and marine all combining to form a stretch of open coast of great variety. There are four Sites of Special Scientific Interest (SSSIs), eleven Sites of Nature Conservation Interest (SNCIs), and two Local Nature Reserves (LNRs) in the study area. Hengistbury Head and Hurst Spit form part of candidate Special Areas of Conservation (cSACs) and Special Protection Areas (SPAs), designated under European Directives for their nature conservation importance. Coastal squeeze is likely to change the character of many sites within the study area, particularly low-lying saltmarsh and reedbeds within Christchurch Harbour. Erosion of Hengistbury Head is also reducing areas of maritime heathland and grassland. Christchurch Borough Council has recently completed a coastal defence scheme at Mudeford Sandbanks due to its strategic importance in defending the town. The existence of the Hurst Spit is vital to the continued protection of the existing saltmarshes and mudflats in the western Solent, which are exhibiting extensive dieback, and are also receding through wave attack. The spit has become short of material as a result of defence construction within Christchurch Bay and in recent years has been reinforced with groynes and shingle recharge. Landscape There is one landscape designation in the study area, the South Hampshire coast Area of Natural Beauty (AONB). Hurst Spit is also considered to be of high landscape importance and is also included within this designation. Within the Countryside Agency‟s Character Initiatives there are two Character Areas of relevance to this study, Dorset Heaths and New Forest. The landscape setting of the study area can mainly be divided into open coast of Christchurch Bay and the naturally sheltered harbour of Christchurch Harbour. Land use and Population The main land uses within the study area include settlements, agriculture, tourism, leisure and recreation. Agriculture within the study area is of varying quality, ranging from Grade 2 in the area of Keyhaven and Milford-on-Sea, to Grade 4 around Milford and Barton. Hampshire County Council characterise the area as open coastal plain. There is little opportunity for agriculture around Christchurch, as the harbour waterfront is highly developed. Christchurch is the main town within the study area and borders the northern edge of Christchurch Harbour. It has a population of 45,000, of which more than 34% are of a pensionable age. Most of the commercial activity is situated here with the major employment sectors being „high technology‟, aviation with industrial sites providing the remaining business. Towns and villages lying to the east of Christchurch include Milford on Sea, New Milton, Barton on Sea and Highcliffe, which are all mainly residential, with tourism and service providing the main employment. Transport Network and Traffic The principal road network is the A35 from Bournemouth to Christchurch. The main railway link is the South Coast route, which is part of the Trans-European rail network. Car and passenger ferries operate between Yarmouth (Isle of Wight) and Lymington, just east of the study area. Passenger ferries operate between Keyhaven and Yarmouth and from Keyhaven to Hurst Castle. Water and Aquatic Environment There are five main rivers within the study area with varying degrees of quality. The River Stour and Avon, feeding into Christchurch Harbour, the Walkford Brook, the Becton Bunny and the Danes Stream, which discharges just beyond the study area, are all are monitored by the Environment Agency for their chemical and biological content (General Quality Assessments), and are set River Quality Objectives (RE classifications), for which they have to meet.