11C08 Heald Brow to Humphrey Head
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Cumbria Coastal Strategy Technical Appraisal Report for Policy Area 11c8 Heald Brow to Humphrey Head (Technical report by Jacobs) © Copyright 2020 Halcrow Group Limited, a CH2M Company. The concepts and information contained in this document are the property of Jacobs. Use or copying of this document in whole or in part without the written permission of Jacobs constitutes an infringement of copyright. Limitation: This document has been prepared on behalf of, and for the exclusive use of Jacobs’ client, and is subject to, and issued in accordance with, the provisions of the contract between Jacobs and the client. Jacobs accepts no liability or responsibility whatsoever for, or in respect of, any use of, or reliance upon, this document by any third party. CUMBRIA COASTAL STRATEGY - POLICY AREA 11C8 HEALD BROW TO HUMPHREY HEAD Policy area: 11c8 Heald Brow to Humphrey Head Figure 1 Sub Cell 11c Arnside to Hodbarrow Point Location Plan of policy units. Baseline mapping © Crown copyright and database rights, 2019. Ordnance Survey licence number: 1000019596. 1 CUMBRIA COASTAL STRATEGY - POLICY AREA 11C8 HEALD BROW TO HUMPHREY HEAD Figure 2 Location of policy area 11c8: Heald Brow to Humphrey Head. Baseline mapping © Crown copyright and database rights, 2019. Ordnance Survey licence number: 1000019596. 2 CUMBRIA COASTAL STRATEGY - POLICY AREA 11C8 HEALD BROW TO HUMPHREY HEAD 1 Introduction 1.1 Location and site description Policy units: 11c8.1 Heald Brow to Frith Wood 11c8.2 New Barns 11c8.3 Grubbins Wood (New Barns to Ash Meadow) 11c8.4 Ash Meadow to the Kent Viaduct (Arnside) 11c8.5 Kent Viaduct to Holme Island 11c8.6 Holme Island to Humphrey Head (Grange-over-Sands) Responsibilities: South Lakeland District Council Cumbria County Council Location: This policy area covers the banks of the outer Kent Estuary running along the east bank from Arnside to the viaduct, and the viaduct to Humphrey Head on the west bank. Site overview: The estuary is constrained at Arnside by the Kent Railway Viaduct and at Sandside by high ground. The east bank of the outer estuary, between Arnside and Blackstone Point, is backed by limestone cliffs and pocket shingle beaches, fronted by intertidal sandflats. Rock platforms extend seaward formed from the erosion of the limestone cliffs. Along the west bank, between the railway viaduct and the promontory of Humphrey Head a series of limestone outcrops of varying height fringe the shoreline. In other locations, the sloping hinterland is slightly set back from the present shoreline position. The main river channel runs close to the shore between Blackstone Point and the Railway Viaduct. The estuary falls within Morecambe Bay Ramsar, Site of Special Scientific Interest, Special Area of Conservation and Special Protection Area designations. The area forms one of the two largest areas of intertidal estuarine flats in Britain; internationally significant for wintering wading birds and nationally important for wintering wildfowl. This area has significant landscape value: parts of the estuary lie within the Lake District National Park and World Heritage Site and Arnside to Silverdale Area of Outstanding Natural Beauty. There are two main settlements within the policy area, which is typically sparsely populated: the small town of Grange-over-Sands and the village of Arnside. The key infrastructure within the area is the Cumbrian Coastal Railway Line which crosses the Kent Estuary at Arnside and runs along the coastline on the west bank of the Kent. The A590 is the key transport link in this area, albeit set back from the coast, but there are also minor roads linking communities. 3 CUMBRIA COASTAL STRATEGY - POLICY AREA 11C8 HEALD BROW TO HUMPHREY HEAD 1.2 Current SMP policy The policy details for this policy area are shown here, taken directly from the SMP2 (Halcrow, 2011). All policy units within this frontage have been identified as non priority areas and have been greyed out. Overview: The long term plan is to continue to manage flood and erosion risks to property and infrastructure, although some local opportunities for habitat creation to mitigate future coastal squeeze exist through realignment east of Grange- over-Sands. The proposed policies manage risk to people, property and infrastructure in a sustainable manner whilst maintaining the natural character of the section. In the long term, opportunities for additional habitat creation exist if required for compensatory habitat for areas experiencing coastal squeeze elsewhere in the Shoreline Management Plan region. Location Policy and Approach (from 2010) 0-20 years 20-50 years 50-100 years 11c8.1 Heald Brow to No active intervention – No active intervention – No active intervention – Frith Wood Allow shoreline to continue to Allow shoreline to continue to Allow shoreline to continue to evolve under natural evolve under natural evolve under natural processes. processes. processes. 11c8.2 New Barns No active intervention – Due No active intervention – Due No active intervention – Due to lack of economic to lack of economic to lack of economic justification. However private justification. However private justification. However private defences may be permitted defences may be permitted defences may be permitted subject to consent. subject to consent. subject to consent. 11c8.3 Grubbins Wood No active intervention – No active intervention – No active intervention – (New Barns to Allow shoreline to continue to Allow shoreline to continue to Allow shoreline to continue to Ash Meadow) evolve under natural evolve under natural evolve under natural processes. processes. processes. 11c8.4 Ash Meadow to Hold the line – Hold the line – Manage flood Hold the line – Manage flood the Kent Manage flood and erosion risk and erosion risk by and erosion risk by Viaduct by maintaining existing maintaining existing defences. maintaining existing defences. (Arnside) defences. 11c8.5 Kent Viaduct to Hold the line – Manage flood Hold the line – Manage flood Hold the line –Manage flood Holme Island risk to railway line by risk to railway line by risk to railway line by maintaining existing defences maintaining existing defences maintaining existing defences to an adequate standard. to an adequate standard. to an adequate standard. Undertake studies to consider Possible habitat creation potential habitat creation through regulated tidal Managed realignment to exchange scheme. manage coastal squeeze in longer term. 11c8.6 Holme Island to Hold the line – Manage flood Hold the line – Manage flood Hold the line – Manage flood Humphrey and erosion risk by and erosion risk by and erosion risk by Head (Grange- maintaining existing defences maintaining existing defences maintaining existing defences over-Sands) to an adequate standard. to an adequate standard. to an adequate standard. 4 CUMBRIA COASTAL STRATEGY - POLICY AREA 11C8 HEALD BROW TO HUMPHREY HEAD 2 Appraisal of non priority units There are six policy units within this policy area, all of which have been defined as non priority units, with no priority units identified: • 11c8.1 Heald Brow to Frith Wood • 11c8.2 New Barns • 11c8.3 Grubbins Wood (New Barns to Ash Meadow) • 11c8.4 Ash Meadow to the Kent Viaduct (Arnside) • 11c8.5 Kent Viaduct to Holme Island • 11c8.6 Holme Island to Humphrey Head (Grange-over-Sands) A light touch review has been undertaken of current SMP recommendations, taking into account conclusions from option appraisals for the adjacent frontages, where appropriate. 2.1 11c8.1 Heald Brow to Frith Wood 2.1.1 11c8.1 - Existing approach to flood and coastal erosion risk management The existing SMP2 policy along this frontage (shown in Figure 3) is No active intervention from the short term, to “allow the shoreline to continue to evolve under natural processes.”. The primary justification for the SMP2 policy was that the unit was largely natural high ground frontage with insufficient assets at risk to justify defences. Figure 3 Looking over Jenny Brown’s Point (Heald Brow). 2015 Aerial photograph © North West Regional Monitoring Programme. This undefended section of coast is expected to experience low levels of erosion in the next 100 years. Erosion is anticipated to be in the region of 2 to 5 m in the medium and long term, whilst only up to 2 m has been predicted for the short term. There is no flooding risk, as indicated by Environment Agency Flood Zones 2 & 3. There are no conflicts between the policy for this unit and adjacent units as the policy is the same. 5 CUMBRIA COASTAL STRATEGY - POLICY AREA 11C8 HEALD BROW TO HUMPHREY HEAD 2.1.2 11c8.1 - Strategy considerations Policy Unit 11c8.1 is remote and sparsely populated. There are two seasonal caravan parks backing onto the beach, and a short section of coastal road. There is limited access to the frontage which may become increasingly difficult over time. At the timing of writing, the route of the England Coast Path is still to be confirmed. Policy Unit 11c8.1 falls within the Arnside and Silverdale Area of Outstanding Natural Beauty (AONB) and overlooks the Lake District National Park, which also has recently been designated as a World Heritage Site. Therefore, the site has nationally and internationally significant landscape value. There are two listed buildings within the area, located at the frontage in Heald Brow: Brown’s House and a tower on shore at Jenny Brown’s Point, 120 metres north east of Brown’s House. In addition, there is potential for buried archaeology. National and international nature conservation designations cover the foreshore area of this unit as a part of the Morecambe Bay array of designations (SAC, SPA, Ramsar, SSSI). The status of most of the SSSI units of the foreshore of this policy unit site are currently favourable (last assessed in 2010), with the last inspection noting that coastal processes are unhindered. The condition of both Unit 3 Warton Marsh of Morecambe Bay SSSI and Far Arnside SSSI is currently unfavourable recovering (last assessed in 2009 and 2014, respectively).