Lancaster City Council Strategic Flood Risk Assessment (SFRA)
September 2007 Edition : Final Published Report
Lancaster City Council Planning Services Palatine Hall Dalton Square Lancaster LA1 1PW
Back of Front Cover
Lancaster District SFRA September 2007
The Lancaster District Strategic Flood Risk Assessment - An Introductory Note from Lancaster City Council
This Strategic Flood Risk Assessment (SFRA) for Lancaster District was commissioned and published by Lancaster City Council. The SFRA has been prepared by Jacobs, acting as professional independent engineering consultants to Lancaster City Council.
Existing Flood Map Resources The Environment Agency currently publishes maps that show an indication of the likelihood of flooding on its website. The data that informed the Environment Agency’s flood maps came from a national flood risk assessment completed in 2005, which used ground levels, predicted flood levels, information on flood defences, and local knowledge. The flood risk likelihood is described in one of three categories, low, moderate or significant. The owners of houses and commercial properties should continue to use the Environment Agency’s flood maps as the source of flood risk information that has been prepared in accordance with a nationally consistent methodology and which describes flood risk in the categories used by the insurance industry. Periodically the Environment Agency may review its flood zone maps in the context of further information, and this may include the information provided by the Lancaster District SFRA.
The Environment Agency is also intending to prepare additional flood mapping that will illustrate the beneficial effects of maintained flood defences; further information on this work should be sought from the Environment Agency.
The Purpose of the Lancaster District SFRA The SFRA is a technical document that provides an assessment and over-view of flood risk considerations by collating and appraising available information sources on flood risk; these sources are listed in Chapter 4 of the document.
The SFRA has been prepared to inform the forward planning process, by helping to guide development proposals to the areas with the lowest flood risk in the context of wider sustainability considerations. Developers, land owners and their agents are advised to consider the flood risk implications described in the SFRA, particularly when preparing or contemplating development proposals.
Additionally, to help achieve a positive reduction in the risk of flooding within the District, the SFRA also provides detailed development control recommendations that are intended to assist in the determination of planning applications by, for example, describing in which circumstances a detailed Flood Risk Assessment is required and describing appropriate flood mitigation measures.
The SFRA is an important element of the Local Development Framework (LDF) Evidence Base. The SFRA has been reported to the Cabinet Member with Responsibility for Community Safety, Emergency Planning, Planning Policy, Cycling and Travel Plans.
Note on SFRA Publication as it appears on the City Council’s Website The full text of the Lancaster District SFRA is available to download as Document IBP 9 from the Evidence Base page of the Local Development Framework area at www.lancaster.gov.uk/LDF.
The text provides, at Chapter 6, a description of the over-view of flood risk in a series of 15 Character Areas and, in Appendix B, a summary table that shows which land uses are permissible within some key sites contained within these Character Areas. These areas were chosen for consideration on the basis that consideration of flood risk at these locations would most helpfully inform preparation of the emerging Local Development Framework documents. However the Character Area plans, which are large files, are not available to download from the website. The Character Area plans provide a detailed over-view of flood risk for the selected areas only – this includes the sub- division of Flood Zone 3 into Planning Policy Statement (PPS) 25 Flood Zones 3b (Functional Floodplain) and 3a (High Probability). Whilst the Character Areas plans do not represent Flood Risk Assessments for individual sites, they may indicate that further consideration needs to be given to flood risk in the context of development proposals. This further consideration may need to be addressed by site-specific Flood Risk Assessments.
The detailed Character Area plans may be viewed, in the context of both the text of the document, and advice and interpretation on the status and significance of the flood zones indicated, only from Lancaster City Council’s planning and engineering officers at the offices of the Planning Service at Palatine Hall, Dalton Square Lancaster, LA1 1PW, or, from the Environment Agency.
For further information on the Lancaster District is SFRA please contact the City Council’s Forward Planning Team at Lancaster on 01524 582330 or by e-mail at [email protected].
Lancaster City Council Planning Services October 2007
Lancaster City Council STRATEGIC FLOOD RISK ASSESSMENT (SFRA)
Glossary
Annual Exceedance Probability e.g. 1% AEP is equivalent to 1% probability AEP of occurring in any one year (or, on average, once in every 100 years)
AOD Above Ordnance Datum
CFMP Catchment Flood Management Plan
Areas delineated for flood risk evaluation within the SFRA of similar Character Areas flooding characteristics.
The Development Plan Document within the Council’s Local Development Framework which sets the long-term vision and objectives for the area. It Core Strategy contains a set of strategic policies that are required to deliver the vision including the broad approach to development.
CLG Communities and Local Government
Defra Department of Environment, Food and Rural Affairs
The carrying out of building, engineering, mining or other operations, in, on, Development over or under land, or the making of any material change in the use of a building or other land.
A spatial planning document within the Council’s Local Development Development Plan Framework which set out policies for development and the use of land. Document (DPD) Together with the Regional Spatial Strategy they form the development plan for the area. They are subject to independent examination.
DPD Development Planning Document
EA Environment Agency
Nationally consistent delineation of ‘high’ and ‘medium’ flood risk, published Flood Zone Map on a quarterly basis by the Environment Agency
Formal Flood Defence A structure built and maintained specifically for flood defence purposes
PPS25 Flood Zone, defined as areas at risk of flooding in the 5% AEP (20 Functional Floodplain year) design event
A room used as living accommodation within a dwelling but excludes bathrooms, toilets, halls, landings or rooms that are Habitable Room only capable of being used for storage. All other rooms, such as kitchens, living rooms, bedrooms, utility rooms and studies are counted.
A structure that provides a flood defence function, however has not been Informal Flood Defence built and/or maintained for this purpose (e.g. boundary wall)
LAPM DPD Land Allocations and Proposals Map Development Plan Document
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Local Development Consists of a number of documents which together form the spatial strategy Framework (LDF) for development and the use of land
A series of notes issued by the Government, setting out policy guidance on Planning Policy Guidance different aspects of planning. They will be replaced by Planning Policy (PPG) Statements.
A series of statements issues by the Government, setting out policy Planning Policy guidance on different aspects of planning. They will replace Planning Policy Statement (PPS) Guidance Notes
Overland flows that accumulate prior to reaching a watercourse or drainage Pluvial Flooding system
Planning Policy Statement 25: Development and Flood Risk PPS25 Department of Community & Local Government, 2006 Land which is or was occupied by a building (excluding those used for Previously Developed agriculture and forestry). It also includes land within the curtilage of the (Brownfield) Land building, for example a house and its garden would be considered to be previously developed land.
PRIA Partial Regulatory Impact Assessment.
A measure of the outstanding flood risks and uncertainties that have not Residual Risk been explicitly quantified and/or accounted for as part of the review process
SUDS Sustainable Drainage System
SEA Strategic Environmental Assessment
SMP Shoreline Management Plan
Supplementary Planning Provides supplementary guidance to policies and proposals contained Document (SPD) within Development Plan Documents. They do not form part of the development plan, nor are they subject to independent examination.
Sustainability Appraisal Appraisal of plans, strategies and proposals to test them against (SA) broad sustainability objectives.
Development that meets the needs of the present without compromising the Sustainable Development ability of future generations to meet their own needs” (The World Commission on Environment and Development, 1987).
PPS25 Flood Zone, defined as areas at risk of flooding in events that Zone 1 Low Probability exceed the 0.1% AEP (1000 year) design event
PPS25 Flood Zone, defined as areas at risk of flooding in events that are Zone 2 Medium greater than the 1% AEP (100 year), and less than the 0.1% AEP (1000 Probability year) design event
PPS25 Flood Zone, defined as areas at risk of flooding in the 1% AEP (100 Zone 3a High Probability year) design event
Zone 3b Functional Defined as areas at risk of flooding in the 5% AEP (20 year) design event. Floodplain
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EXECUTIVE SUMMARY
Introduction
1. Lancaster District includes the historic city of Lancaster, the coastal towns of Morecambe and Heysham, the railway town of Carnforth and a rural area which is characterised by large villages and scattered hamlets.
2. The Lancaster District Local Plan 1996-2006 sets out the Council’s current proposals for the development and use of land in the area. Development within the City is currently focussed very much upon a strategy of urban concentration and the protection of the Green Belt.
3. The Council is currently preparing a Local Development Framework (LDF) in accordance with the Planning and Compulsory Purchase Act 2004. The emerging spatial development strategy will retain the focus of directing future development within the urban areas.
4. The River Lune and its tributaries is a dominant feature of the Lancaster District. A large proportion of the District’s communities are situated either adjacent to, or near, the River Lune and/or its tributaries, representing a potential risk of river flooding to some properties. The District of Lancaster also features a coastal boundary to the west, and during extreme tides a large number of properties within Morecambe are protected against flooding by the presence of raised coastal flood defences.
5. Whilst historically the risk of flooding from rivers and the sea within the District of Lancaster has been relatively high, investment in flood defence has markedly reduced this risk in the most critical (at risk) areas. The District is characterised by well defined river valleys, and consequently the potential risk of river flooding into low lying (undefended) areas is generally low. Finally, few problems associated with localised flooding from other sources, for example surface water runoff, sewer flooding and/or culvert blockage, are evident within the District.
6. In summary, the current risk of flooding within Lancaster is relatively low, and flood risk is not a ‘big’ local issue that is likely to overly constrain the allocation of land for future development. Notwithstanding this however, it is important to recognise that flood defences do not fully remove the risk of flooding. Future investment in maintenance, and possibly the raising of defences to combat the potential impacts of climate change, will be imperative to ensure that these mitigating structures represent a sustainable solution for the District in the long term.
Why carry out a Strategic Flood Risk Assessment (SFRA)?
7. Flooding can result not only in costly damage to property, but can also pose a risk to life and livelihood. It is essential that future development is planned carefully, steering it away from areas that are most at risk from flooding, and ensuring that it does not exacerbate existing known flooding problems.
8. Planning Policy Statement (PPS) 25: Development and Flood Risk has been developed to underpin decisions relating to future development (including urban regeneration) within areas that are subject to flood risk. In simple terms, PPS25 requires local planning authorities to review the variation in flood risk across their district, and to steer vulnerable development (e.g. housing) towards areas of lowest risk. Where this cannot be achieved and development is to be permitted in areas that may be subject to some degree of flood risk, PPS25 requires the Council to demonstrate that there are sustainable mitigation solutions available that will ensure that the risk to property and life is minimised (throughout the lifetime of the development) should flooding occur.
September2007 (Final) iv Lancaster City Council STRATEGIC FLOOD RISK ASSESSMENT (SFRA)
9. The Strategic Flood Risk Assessment (SFRA) is the first step in this process, and it provides the building blocks upon which the Council’s planning and development control decisions are made.
What is a Strategic Flood Risk Assessment (SFRA)?
10. The Lancaster District Strategic Flood Risk Assessment (SFRA) has been carried out to meet the following key objectives:
¾ To collate all known sources of flooding, including river, tidal, surface water (local drainage), sewers and groundwater, that may affect existing and/or future development within the District;
¾ To delineate areas that have a ‘low’, ‘medium’ and ‘high’ probability of flooding within the District, in accordance with Planning Policy Statement 25 (PPS25), and to map these:
- Areas of ‘high’ probability of flooding are assessed as having a 1 in 100 or greater chance of fluvial flooding (>1%) or a 1 in 200 or greater chance of tidal flooding (>0.5%) in any year, and are referred to as High Risk Zone 3;
- Areas of ‘medium’ probability of flooding are assessed as having between a 1 in 100 (1%) fluvial, 1 in 200 (0.5%) tidal and 1 in 1000 (0.1%) chance of fluvial and/or tidal flooding in any year, and are referred to as Zone 2 Medium Probability;
- Areas of ‘low’ probability of flooding are assessed as having a less than 1 in 1000 chance of flooding (<0.1%) in any year, and are referred to as Zone 1 Low Probability.
¾ Within flood affected areas, recommend appropriate land uses (in accordance with the PPS25 Sequential Test) that will not unduly place people or property at risk of flooding.
11. Where flood risk has been identified as a potential constraint to future development, recommend possible flood mitigation solutions that may be integrated into the design (by the developer) to minimise the risk to property and life should a flood occur (in accordance with the PPS25 Exception Test).
The Sequential Test
12. The primary objective of PPS25 is to steer vulnerable development towards areas of lowest flood risk. PPS25 advocates a sequential approach that will guide the planning decision making process (i.e. the allocation of sites). In simple terms, this requires planners to seek to allocate sites for future development within areas of lowest flood risk in the initial instance. Only if it can be demonstrated that there are no suitable sites within these areas should alternative sites (i.e. within areas that may potentially be at risk of flooding) be contemplated. This is referred to as the Sequential Test.
13. As an integral part of the sequential approach, PPS25 stipulates permissible development types. This considers both the degree of flood risk posed to the site, and the likely vulnerability of the proposed development to damage (and indeed the risk to the lives of the site tenants) should a flood occur.
14. The PPS25 Sequential Test is depicted in Figure 3.1 of the Practice Guide Companion to PPS25 (Draft, February 2007) and Section 6.4 of this document.
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The Exception Test
15. Many towns within England are situated adjacent to rivers, and are at risk of flooding. The future sustainability of these communities relies heavily upon their ability to grow and prosper. PPS25 recognises the importance of seeking a careful balance between the risk that flooding may pose to a community, and the many other (non flood related) sustainability issues that must be delivered through the planning process.
16. For this reason, PPS25 provides an Exception Test. Where a local planning authority has identified that there is a strong planning based argument for a development to proceed that does not meet the requirements of the Sequential Test, it will be necessary for the Council to demonstrate that the Exception Test can be satisfied.
17. For the Exception Test to be passed it must be demonstrated that:
¾ “the development provides wider sustainability benefits to the community that outweigh flood risk, informed by a SFRA where one has been prepared. If the DPD has reached the ‘submission’ stage, the benefits of the development should contribute to the Core Strategy’s Sustainability Appraisal;
¾ the development should be on developable, previously developed land or if it is not on previously developed land, that there are no reasonable alternative sites on previously developed land; and
¾ a SFRA must demonstrate that the development will be safe, without increasing flood risk elsewhere, and where possible, will reduce flood risk overall.”
Outcomes of the Lancaster SFRA
18. Lancaster District has been delineated into zones of low, medium and high probability of flooding, based upon existing available information provided by the Environment Agency. Detailed flood risk mapping has been made available for the River Wenning, Backlane and the River Keer. The Environment Agency Flood Zone Maps (January 2007) have been adopted as the basis for the SFRA for other watercourses.
19. A number of towns and villages are situated within the 1% (100 year) fluvial flood extent or 0.5% (200 year) tidal flood extent (i.e. within the ‘high’ probability zone), including the principal centres of Morecambe, Carnforth and the Luneside areas of Lancaster which form a primary focus for future development within the District. Considerable investment has been made in flood defence improvements within the area, increasing the standard of protection provided to existing property within the District. Flood defence schemes include the Morecambe Coastal Works Scheme (providing protection to Morcambe) and the River Lune flood alleviation scheme (increasing the standard of protection provided to land situated to the south of the River Lune). There is always a residual risk however that these defences may be overtopped in more extreme flood events or fail in some way, and therefore it is crucially important that future development takes careful consideration of the possible risk to life should a flood occur.
Zone 3b (Functional Floodplain)
20. Areas subject to flooding up to (and including) once in every 20 years on average have been delineated. These areas have been sub-delineated on the basis of current land use, i.e. open space or currently undeveloped areas (i.e ‘Zone 3b Functional Floodplain (Undeveloped)’) vs areas that are ‘previously developed’ (i.e. ‘Zone 3b Functional Floodplain (Developed)’). Within the context of the SFRA, ‘previously developed’ areas are solely existing buildings that are impermeable to floodwaters. The land surrounding these buildings are important flow paths and/or flood storage areas that must be retained.
September2007 (Final) vi Lancaster City Council STRATEGIC FLOOD RISK ASSESSMENT (SFRA)
21. It is important to recognise that all areas within Zone 3b are areas that are subject to relatively frequent flooding, and may be subject to fast flowing and/or deep water. Whilst it may be impractical to refuse all future regeneration within these areas, careful consideration must be given to future sustainability. A suite of spatial planning and development control policies have been developed accordingly.
Zone 3a High Probability
22. Areas subject to flooding up to (and including) once in every 100 years as a result of fluvial (river) flooding, and once in every 200 years as a result of tidal flooding (i.e. Zone 3a High Probability) have been identified. Residential development should be avoided in these areas wherever possible. It is recognised however that there may be strong planning arguments as to why housing may be required in these areas.
23. To meet the requirements of the Exception Test therefore, it will be necessary for the Council to demonstrate that the development provides wider sustainability benefits to the community that outweigh flood risk. The Council must also demonstrate that the development is on developable, previously developed land or if it is not on previously developed land, that there are no reasonable alternative sites on previously developed land.
24. The Town and Country Planning Direction (2007) defines major residential developments as greater than 10 dwellings or 0.5 hectares and major non-residential development as larger than 1 hectare site area or 1,000m2 floor area. Minor developments include extensions to non-residential buildings with a footprint of less than 250m2, all alterations that do not increase the size, and householder developments such as garages or sheds. All developments, regardless of whether they are major or minor, must comply with PPS25
25. The SFRA has outlined specific development control conditions that should be placed upon development within Zone 3a High Probability to minimise both the damage to property, and the risk to life in case of flooding. It is essential that the developer carries out a Flood Risk Assessment (FRA) to consider the site-based constraints that flooding may place upon the proposed development. The detailed investigation provided within the FRA should be commensurate with both the severity of the flood risk and the scale of the proposed development.
Zone 2 Medium Probability
26. Areas subject to flooding in events exceeding the 100 year fluvial event or 200 year tidal event, and up to (and including) once in every 1000 years on average (i.e. Zone 2 Medium Probability) have been identified. Essential community services, including emergency services, should be avoided in these areas. There are generally no other restrictions placed upon future development in these areas, however it is important to ensure that the developer takes account of possible climate change impacts to avoid a possible increase in the risk of flooding in future years (achieved through completion of a simple Flood Risk Assessment).
Zone 1 Low Probability
27. There are no restrictions placed on land use within Zone 1 Low Probability (i.e. all remaining areas of the District). It is important to remember however that development within these areas, if not carefully managed, may exacerbate existing flooding and/or drainage problems downhill. The Environment Agency consider it unreasonable to undertake a simple Flood Risk Assessment for every development. For smaller developments, a brief statement saying that surface water discharged from the site will not be increased (through the adoption of sustainable drainage techniques) is often all that would be required as a simple Flood Risk Assessment.
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The Way Forward
28. A sizeable proportion of the urban region within the Lancaster District is at risk of flooding. The risk of flooding posed to properties within the District arises from a number of sources including river flooding, tidal flooding, localised runoff, sewer and groundwater flooding.
29. Substantial investment in flood defence has been delivered within the District, providing a degree of protection to existing property., Recently a flood wall has been constructed by the Environment Agency, increasing the standard of protection to properties situated to the south of the River Lune. Along the Morecambe coastline, substantial investment has been made into securing (and increasing the standard of protection provided by) the coastal defences. A flexible design has been adopted to ensure that the flood defences can be adapted to mitigate the increased flood risk posed by the potential impacts of climate change. A residual risk of flooding remains however, associated both with an event that may exceed the design capacity of the defences, and/or a structural failure.
30. A planning solution to flood risk management should be sought wherever possible, steering vulnerable development away from areas affected by flooding in accordance with the PPS25 Sequential Test. Specific planning recommendations have been provided for all urban centres within the District.
31. Where other planning considerations must guide the allocation of sites and the Sequential Test cannot be satisfied, specific recommendations have been provided to assist the Council and the developer to meet the Exception Test. These should be applied as development control conditions for all future development.
32. Council’s Core Strategy is essential to ensure that the recommended development control conditions can be imposed consistently at the planning application stage. This is essential to achieve future sustainability within the District with respect to flood risk management. The current flood risk policy is considered robust. It is recommended however that supporting Supplementary Planning Document is developed in light of the suggested development control conditions presented by the Lancaster SFRA.
33. Emergency planning is imperative to minimise the risk to life posed by flooding within the District. It is recommended that the Council review their adopted flood risk response plan in light of the findings and recommendations of the SFRA.
A Living Document
34. The SFRA has been developed building heavily upon existing knowledge with respect to flood risk within the district. A rolling programme of detailed flood risk mapping and strategic flood risk management investigations within the North West region is underway. This, in addition to observed flooding that may occur throughout a year, will improve the current knowledge of flood risk within the District and may marginally alter predicted flood extents within Lancaster. Furthermore, Communities and Local Government (CLG) are working to provide further detailed advice with respect to the application of PPS25, and future amendments to the PPS25 Practice Guide are anticipated. Given that this is the case, a periodic review of the Lancaster District SFRA is imperative.
35. It is recommended that the Lancaster District SFRA is reviewed once every 12 months, commencing in July 2008. A series of key questions to be challenged as part of the SFRA review process are set out in Section 7 of this document.
September2007 (Final) viii Lancaster City Council STRATEGIC FLOOD RISK ASSESSMENT (SFRA)
Table of Contents
1 Introduction ...... 1 1.1 Context and Purpose ...... 1 1.2 Study Area...... 1 2 SFRA Approach ...... 2 3 Policy Framework ...... 4 3.1 Introduction...... 4 3.2 National Policy...... 4 3.2.1 Introduction...... 4 3.2.2 Planning Policy Statement 25: Development and Flood Risk...... 4 3.2.3 Consultation Planning Policy Statement: Planning and Climate Change ...... 5 3.3 Regional Planning Policy ...... 5 3.3.1 Regional Planning Guidance for the North West (RPG13) 2003 ...... 5 3.3.2 The Draft North West Plan 2006 ...... 6 3.3.3 Meeting the Sequential Flood Risk Test – Guidelines for the North West Region (July 2004)...... 7 3.3.4 The Joint Lancashire Structure Plan 2001-2016...... 7 3.4 Local Planning Policy ...... 7 3.4.1 Lancaster District Local Plan 1996-2006...... 7 3.4.2 Lancaster Local Development Framework (LDF) ...... 7 4 Data Collection...... 9 4.1 Overview ...... 9 4.2 Environment Agency Flood Zone Maps...... 9 4.3 Historical Flooding...... 9 4.4 Detailed Hydraulic Modelling...... 10 4.5 Flood Defences ...... 10 4.6 Consultation ...... 11 4.7 Topography ...... 12 5 Flood Risk in Lancaster District ...... 13 5.1 Overview ...... 13 5.2 Delineation of the PPS25 Flood Risk Zones...... 14 5.2.1 Delineation of Zone 3b Functional Floodplain...... 14 5.2.2 Delineation of Zone 3a High Probability ...... 15 5.2.3 Delineation of Zone 2 Medium Probability...... 15 5.2.4 Delineation of Zone 1 Low Probability...... 15 5.3 Assessment of Risk to Life (Flood Hazard)...... 16 5.3.1 Definition of Flood Hazard...... 16 5.3.2 Flood Hazard due to Overbank (Overland) Flooding in Lancaster District ... 16 5.3.3 Flood Hazard due to Flood Defence Failure ...... 17 5.4 Coastal Flooding ...... 17 5.5 Local Drainage Issues...... 17 5.6 Groundwater Issues ...... 18 5.7 Water Supply Infrastructure Failure ...... 18 5.8 Climate Change...... 18 5.9 Residual Risk of Flooding ...... 20 6 Sustainable Management of Flood Risk...... 22 6.1 Overview ...... 22 6.2 Responsibility for Flood Risk Management...... 22 6.3 Strategic Flood Risk Management - The Environment Agency ...... 23 6.3.1 Overview...... 23 6.3.2 Catchment Flood Management Plan (CFMP) ...... 23 6.3.3 Shoreline Management Plan (SMP)...... 24 6.3.4 River Basin Management Plan...... 25 6.4 Planning & Development Control...... 26 6.4.1 Planning Solutions to Flood Risk Management ...... 26 6.4.2 Future Development within Zone 3b Functional Floodplain ...... 28 6.4.3 Future Development within Zone 3b Functional Floodplain ...... 28 6.4.4 Future Development within Zone 3a High Probability ...... 30 6.4.5 Future Development within Zone 2 Medium Probability...... 31 6.4.6 Future Development within Zone 1 Low Probability...... 32 6.5 Overview of Flood Risk ...... 33
September2007 (Final) ix Lancaster City Council STRATEGIC FLOOD RISK ASSESSMENT (SFRA)
6.5.1 General...... 33 6.5.2 Character Area B1 – Silverdale (Refer Figure B1)...... 33 6.5.3 Character Area B2 – Carnforth (Refer Figure B2)...... 33 6.5.4 Character Area B3 – Bolton-le-Sands (Refer Figure B3) ...... 34 6.5.5 Character Area B4 – Slyne-with-Hest (Refer Figure B4) ...... 35 6.5.6 Character Area B5 – Morecambe Central and West End (Refer Figure B5) 35 6.5.7 Character Area B6 – White Lund and Luneside (Refer to Figure B6)...... 36 6.5.8 Character Area B7 – North East Lancaster (Refer to Figure B7)...... 36 6.5.9 Character Area B8 – Halton (Refer to Figure B8) ...... 37 6.5.10 Character Area B9 – Caton and Brookhouse (Refer Figure B9)...... 38 6.5.11 Character Area B10 – West Lancaster (Refer Figure B10)...... 38 6.5.12 Character Area B11 – East Lancaster (Refer Figure B11)...... 39 6.5.13 Character Area B12 – Lancaster University (Refer Figure B12)...... 39 6.5.14 Character Area B13 – Hornby (Refer Figure B13) ...... 40 6.5.15 Character Area B14 –Heysham (Refer Figure B14) ...... 41 6.5.16 Character Area B15 –Middleton (Refer Figure B15) ...... 41 6.5.17 Remaining Areas of the District...... 42 6.5.18 PPS25 Constraints upon Emerging Site Allocations...... 42 6.6 Detailed Flood Risk Assessment (FRA) – The Developer...... 42 6.6.1 Scope of the Detailed Flood Risk Assessment ...... 42 6.6.2 Raised Floor Levels & Basements (Freeboard) ...... 44 6.6.3 Sustainable Drainage (SUDS)...... 44 6.7 Local Community Actions to Reduce Flood Damage ...... 46 6.7.1 Flood Proofing ...... 46 6.8 Emergency Planning ...... 47 6.9 Insurance...... 48 7 Conclusion & Recommendations...... 50 Appendix A ...... 1 Appendix B ...... 1
List of Figures
Figure A Lancaster District Figure B Map Layout Index Figure C Historical Flooding Figure D Localised Flooding Issues Figure E Proposed and Existing Critical Infrastructure Figure F Evacuation Routes
Figure B1 Character Area B1 - Silverdale Figure B2 Character Area B2 - Carnforth Figure B3 Character Area B3 - Bolton-le-Sands Figure B4 Character Area B4 – Slyne-with-Hest Figure B5 Character Area B5 – Morecambe Central and West End Figure B6 Character Area B6 – White Lund and Luneside Figure B7 Character Area B7 – North East Lancaster Figure B8 Character Area B8 - Halton Figure B9 Character Area B9 – Caton and Brookhouse Figure B10 Character Area B11 – Scotforth Figure B12 Character Area B12 – East Lancaster Figure B13 Character Area B13 – Hornby Figure B14 Character Area B14 – Heysham Figure B15 Character Area B15 – Middleton
September2007 (Final) x Lancaster City Council STRATEGIC FLOOD RISK ASSESSMENT (SFRA) A Technical Report Supporting the Submission of the LCC Core Strategy and Policies DPD
September2007 (Final) xi Lancaster City Council STRATEGIC FLOOD RISK ASSESSMENT (SFRA)
1 Introduction
1.1 Context and Purpose
36. Many of the major towns and villages within the Lancaster District are situated either adjacent to the coastline or the River Lune and its tributaries. Flooding represents a risk to both property and life. It is essential therefore that planning decisions are informed, and take due consideration of the risk posed to (and by) future development by flooding.
37. Planning Policy Statement (PPS) 25: Development and Flood Risk (December 2006) requires that local planning authorities prepare a SFRA in consultation with the Environment Agency. The primary purpose of the SFRA is to determine the variations in flood risk across the District. Robust information on flood risk is essential to inform and support the Council’s revised flooding policies in its emerging Local Development Framework (LDF). Jacobs was commissioned by Lancaster City Council in November 2006 to develop a Strategic Flood Risk Assessment (SFRA).
38. The SFRA for the District will inform, and is being developed in tandem with, the Council’s Core Strategy Development Plan Document. The SFRA forms part of the Council’s evidence base for its Submission Core Strategy. It is a technical document that will be submitted to the Secretary of State with the submission Core Strategy DPD. This SFRA will be developed and refined over time and will feed into the Council’s emerging ‘issues and options’ consultation document on its site allocations (Land Allocations and Proposals Map Development Plan Document (LAPM DPD)).
1.2 Study Area
39. The study area encompasses the District of Lancaster (refer Figure A). The area of the District is 565 square kilometres and has a population of 133,900 (2001 Census). Please note that this SFRA does not consider the Yorkshire Dales National Park.
40. The District includes the large settlements of historic Lancaster, and resort towns of Morecambe and Heysham. There are also a number of smaller settlements within the District including Silverdale, Carnforth, Bolton-le-Sands, Slyne, Hest Bank, Galgate, Halton, Caton, Brookhouse, Hornby and Wray.
41. Over 90% of the area of Lancaster District is rural, and around 34,000 people live in these rural areas. Around half of this proportion of the population lives in large suburban villages close to Lancaster such as Bolton–le–sands, Halton and Galgate. The remainder live in the sparse rural hinterland of the District.
42. The urban areas of Morecambe and Heysham, Lancaster and Carnforth contain most of the district’s population and community associated infrastructure. The planning strategy for the district directs around 90% of development to Lancaster, Morecambe, Heysham and Carnforth. .
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Lancaster City Council STRATEGIC FLOOD RISK ASSESSMENT (SFRA)
2 SFRA Approach
43. The primary objective of the Lancaster District SFRA is to inform the revision of flooding policies, including the allocation of land for future development, within the emerging Local Development Framework (LDF). The SFRA has a broader purpose however, and in providing a robust depiction of flood risk across the District, it can:
¾ Inform the development of Council policy that will underpin decision making within the District, particularly within areas that are affected by (and/or may adversely impact upon) flooding;
¾ Assist the development control process by providing a more informed response to development proposals affected by flooding, influencing the design of future development within the District;
¾ Help to identify and implement strategic solutions to flood risk, providing the basis or possible future flood attenuation works;
¾ Support and inform the Council’s emergency planning response to flooding.
44. The Government provides no specific methodology for the SFRA process. Therefore, to meet these broader objectives, the SFRA has been developed in a pragmatic manner in close consultation with both the Council and the Environment Agency.
45. A considerable amount of knowledge exists with respect to flood risk within the District, including information relating both to historical flooding, and the predicted extent of flooding under extreme weather conditions (i.e. as an outcome of detailed flood risk modelling carried out by the Environment Agency). The Lancaster SFRA has built heavily upon this existing knowledge, underpinning the delineation of the District into zones of ‘high’, ‘medium’ and ‘low’ probability of flooding, in accordance with PPS25. These zones have then been used to provide a robust and transparent evidence base for the development of flooding related policy, and the allocation of sites for future housing and employment uses.
46. A summary of the adopted SFRA process is provided in the figure on the following page, outlining the specific tasks undertaken, and the corresponding structure of the SFRA report.
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47. A number of authorities within the North West are carrying out similar strategic flood risk investigations at the current time. Whilst the delivery teams and programmes underpinning these studies vary from one district to the next, all are being developed in close liaison with the Environment Agency. Consistency in adopted approach and decision making with respect to the effective management of flood risk throughout the North West is imperative. Regular discussions with the Environment Agency have been carried out throughout the SFRA process to this end, seeking clarity and consistency where needed.
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3 Policy Framework
3.1 Introduction
48. This section provides a brief overview of the strategy and policy context relevant to flood risk in the Lancaster District.
49. The success of the SFRA is heavily dependent upon the Council’s ability to implement the recommendations put forward for future sustainable flood risk management, both with respect to planning decisions and development control conditions (refer Section 6.5). A framework of national and regional policy directive is in place, providing guidance and direction to local planning authorities. Ultimately however, it is the responsibility of the Council to establish robust policies that will ensure future sustainability with respect to flood risk.
3.2 National Policy
3.2.1 Introduction
50. This section provides a brief overview of planning policy relating to Lancaster District in terms of flood risk. The SFRA is a key point of reference to the Council in developing their flood risk policies, and this part of the document is designed to facilitate policy development. 51. The success of the SFRA is heavily dependent upon the Council’s ability to implement the recommendations put forward for future sustainable flood risk management, both with respect to planning decisions and development control conditions (refer Section 6). A framework of national and regional policy directives is in place, providing guidance and direction to local planning authorities. Ultimately, however, it is the responsibility of the Council to establish robust policies that will ensure future sustainability with respect to flood risk.
3.2.2 Planning Policy Statement 25: Development and Flood Risk1
52. Planning Policy Statement 25 (PPS25) was published in December 2006 and sets out the planning objectives for flood risk management. It states that all forms of flooding and their impacts are material planning considerations, which gives much weight to the issue of flooding. The aim of PPS25 is to ensure that flood risk is taken into account at all stages of the planning process in order to prevent inappropriate development in ‘at risk’ areas. 53. The key objectives for planning are appraising, managing and reducing flood risk. To appraise the risk it is stated that flood risk areas need to be identified, and that the level of risk needs to be identified. To facilitate this, PPS25 indicates that Regional Flood Risk Appraisals and Strategic Flood Risk Assessments should be prepared. 54. To manage the risk, Local Planning Authorities (LPAs) need to develop policies which “avoid flood risk to people and property where possible, and manage any residual risk, taking account of the impacts of climate change”. LPAs should also only permit development in flood risk areas if there are no feasible alternatives located in areas of lower flood risk.
1 Communities and Local Government (2006) Planning Policy Statement 25: Development and Flood Risk September 2007 (Final) 4
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55. To reduce the risk, PPS25 indicates that land needed for current or future flood management should be safeguarded; new development should have an appropriate location, layout and design and incorporate sustainable drainage systems (SUDS); and new development should be seen as an opportunity to reduce the causes and impacts of flooding by measures such as provision of flood storage, use of SUDS, and re-creating the functional flood plain. 56. A partnership approach is stressed in PPS25 to ensure that LPAs work with partners such as the Environment Agency. The Environment Agency can provide both information and advice relating to flood risk, and should always be consulted when preparing policy or making decisions which will have an impact on flood risk. 57. The future impacts of climate change are highlighted in PPS25, as climate change will lead to increased flood risk in many places in the years ahead. When developing planning policy, LPAs need to consider if it is necessary to encourage the relocation of existing development to locations at less of a risk from flooding in order to prevent future impacts of flooding. 58. PPS25 also gives specific advice for determining planning applications, which needs to be considered when developing policy. LPAs should ensure that flood risk assessments (FRAs) are submitted with planning applications where this is appropriate; they should apply the sequential approach (defined in the PPS) which ensures that lower risk areas are considered preferable to higher risk areas; priority should be given to the use of SUDS; and new development should be designed to be resilient to flooding as appropriate. 59. The Practice Guide Companion to PPS25 was released in draft form for consultation by Communities and Local Government in February 2007. The companion guide provides additional guidance on the principles set out in PPS25, including the definition and delineation of the flood zones (in particular Zone 3b Functional Floodplain), and the application of the Sequential and Exception Tests.
3.2.3 Consultation Planning Policy Statement: Planning and Climate Change2
60. The proposed planning policy statement for climate change was published for consultation in December 2006. When finalised, it will supplement the existing PPS1: Delivering Sustainable Development. The document highlights the issue of climate change, and sets out ways planning should prepare for its effects, which includes managing flood risk. Little detail is given about flooding in this document as PPS25 already does this.
3.3 Regional Planning Policy
3.3.1 Regional Planning Guidance for the North West (RPG13) 2003
61. Regional planning policies provide the overarching framework for the preparation of a LDF. Regional Planning Guidance for the North West (RPG13) was published in 2003 and provides guidance for a 20 year period.
62. Policy SD3 identifies Lancaster and Morecambe as key towns, situated outside of the North West Metropolitan Area, within which 2,690 units per annum (Policy UR7) are to be sought.
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63. Policy ER8 relates to development and flood risk and requires that the precautionary principle is applied in preparing development plans. In this regard, local authorities should:
¾ “ensure built development is wholly exceptional and limited to essential transport and utilities infrastructure in areas of functional floodplain; ¾ Apply the precautionary principle, using the sequential approach to developments in areas at risk of flooding. In the North West, areas of greatest risk include… the Lower Lune Valley; ¾ Discourage inappropriate development which could lead to flood risk elsewhere either by reducing the ability of flood plains to store floodwaters or by creating unacceptable increases in surface run-off; ¾ Promote the use of Sustainable Drainage Systems (SUDS) in all new development; ¾ Support the protection, management and development of flood defences; and, ¾ Take account of the longer term impacts of climate change.
3.3.2 The Draft North West Plan 2006
64. Under the Planning and Compulsory Purchase Act 2004, RPG13 is to be replaced by a new Regional Spatial Strategy, entitled the North West Plan. The North West Plan is being prepared by the North West England Regional Assembly (NWRA) and a Draft document was submitted to the Government in January 2006. It sets out the vision for the region through to 2021. The examination into the North West Plan began in January 2007 and the final plan is expected to be published late 2007.
65. The Draft Plan seeks to support development in Lancaster which will secure urban regeneration and economic growth and create a balanced network of strong and distinctive urban centres within the North West (Policy RDF1). In addition, the Draft Plan proposes that 7,200 net additional dwellings should be built in Lancaster between 2003 and 2021 (Policy L4).
66. With regard to the overall spatial policy for North Lancashire, Policy CNL4 states that plans and strategies will secure the regeneration of Morecambe; provide new sensitively located development in Lancaster; build on opportunities offered by Lancaster University and knowledge employment; support the role of the port of Heysham and develop proposals for traffic management with Lancaster and Morecambe.
67. Policy EM5 Integrated Water Management requires the implementation of the document ‘Meeting the Sequential Flood Risk Test – Guidelines for the North West Region’. In addition, the policy also requires that any development which exceptionally must take place in current or future flood risk areas is resilient to flooding; protected to appropriate standards and does not increase the risk of flooding elsewhere. Policy EM5 also requires the incorporation of SUDS and raising people’s awareness of flood risks.
68. The Draft Regional Spatial Strategy (RSS) was taken to an Examination in Public in January 2007, and the Inspector’s Panel Report was published in May 2007. A series of proposed changes have been recommended, and these will be incorporated during the latter half of 2007. The Panel Report emphasises the importance of Lancaster as a key area of investment for the region, highlighting the essential need for ensuring sustainable growth within the city. It is anticipated that the final RSS will be delivered in early 2008.
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3.3.3 Meeting the Sequential Flood Risk Test – Guidelines for the North West Region (July 2004)
69. Meeting the Sequential Flood Risk Test – Guidelines for the North West Region was published in July 2004 and seeks to provide a robust yet pragmatic approach to the sequential test. It provides a step by step methodology in terms of delineating areas of flood risk, identifying areas subject to development pressure, assessment of actual risk and review of planning constraints. It must be highlighted however that this document was developed prior to the release of PPS25, and therefore does not fully reflect the most recent policy guidance.
3.3.4 The Joint Lancashire Structure Plan 2001-2016
70. The Joint Lancaster Structure Plan 2001-2016 provides the strategic framework for the preparation of Local Development Frameworks and was adopted in March 2005. The Development Strategy for North Lancashire seeks to retain internal population growth, direct future growth towards regeneration priorities in coastal towns, invest in the Heysham-M6 link road and release strategic greenfield land at Bailrigg, Lancaster for economic development.
71. The main development locations within the Lancashire area include Lancaster, Morecambe and Heysham. The Structure Plan requires that the Lancaster area provides for 5,120 new dwellings and 35 hectares of business and industrial land between 2001 and 2016.
72. Policy 24 of the Structure Plan states that “in developed high flood risk areas, development will be limited to proposals for which appropriate flood alleviation measures either exist or will be provided by the developer. In undeveloped or sparsely developed high risk flood areas, development will be limited to proposals for which the particular location is essential. In functional floodplains, development will be limited to proposals which comprise essential infrastructure which cannot be located elsewhere. In all areas:
• Development that could compromise existing flood defences or increase flood risk will be avoided; • Development that reduces flood risk or aids the operation of functional flood plains will be promoted; • Sustainable Drainage will be used in new development where practicable.
3.4 Local Planning Policy
3.4.1 Lancaster District Local Plan 1996-2006
73. The Lancaster District Local Plan 1996-2006 sets out the Council’s proposals for the development and use of land in the District for that period. The Plan was formally adopted in April 2004. The Local Plan is currently under review and will be replaced by the Local Development Framework.
74. With respect to development affecting flood plains, Policy E11 states that development proposals within areas at risk of flooding will only be permitted where appropriate flood measures are already in place or will be provided without adverse environmental impacts.
3.4.2 Lancaster Local Development Framework (LDF)
75. Lancaster City Council is in the early stages of preparing its Local Development Framework (LDF). In accordance with Section 15 of The Planning and Compulsory Purchase Act 2004, the Council has prepared a Local Development Scheme (LDS) that sets out the Council’s project plan for the production of documents, plans and policies that are to be included in the LDF by 2008.
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76. The LDF will be a portfolio of Development Plan Documents (DPDs) and Supplementary Planning Documents (SPDs). The Local Development Scheme which provides a programme for the preparation of the LDF was published in March 2005.
77. The Core Strategy document was submitted to and approved by Lancaster City Council on 12 July 2006. It was submitted to the Secretary of State on the 4th May 2007. The hearing sessions are currently scheduled to commence on Tuesday 4 March 2008. Policy SC7 has been developed to deal specifically with the issue of flood risk within the District, and states:
”Flood Defence Schemes will be completed for the Luneside and Central Morecambe Regeneration Priority Areas.
The Council will prepare a Strategic Flood Risk assessment defining areas of high risk and low to medium risk of flooding.
Development proposals and allocations will be assessed in line with the search sequence set out in Planning Policy Statement 25 on Development and Flood Risk.”
78. It is appreciated that Core Strategy policy should not duplicate national policy, and the supporting text within the Core Strategy submission document does seek to emphasise the importance of the Sequential Test. To this end, the current flood risk policy is considered generally robust. It is recommended however that supporting Supplementary Planning Document is developed in light of the suggested development control recommendations presented by the Lancaster District SFRA.
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4 Data Collection
4.1 Overview
79. A considerable amount of knowledge exists with respect to flood risk within the Lancaster District, including (but not limited to):
¾ Historical river flooding information; ¾ Information relating to localised flooding issues (surface water, groundwater and/or sewer related), collated in consultation with the Council and the Environment Agency; ¾ Detailed flood risk mapping; ¾ Environment Agency Flood Zone Maps (January 2007); ¾ Topography (LiDAR).
80. All of this data has been sourced from the Council and the Environment Agency, forming the core dataset that has informed the SFRA process. The application of this data in the delineation of zones of ‘high’, ‘medium’ and ‘low’ probability of flooding, and the formulation of planning and development control recommendations, is explained in Section 5 below. An overview of the core datasets, including their source and their applicability to the SFRA process, is outlined below.
4.2 Environment Agency Flood Zone Maps
81. The Environment Agency’s Flood Map shows the natural floodplain, ignoring the presence of defences, and therefore areas potentially at risk of flooding from rivers or the sea. The Flood Map shows the area that is susceptible to a 1 in 100 (1% annual exceedance probability or AEP) chance of flooding from rivers in any one year, and/or a 1 in 200 (0.5% AEP) chance of flooding from the sea in any one year. It also indicates the area that has a 1 in 1000 (0.1% AEP) chance of flooding from rivers and/or the sea in any given year. This is known as the Extreme Flood Outline.
82. The Flood Map outlines have been produced from a combination of a national generalised computer model, more detailed local modelling (if available), and some historic flood event outlines. The availability of detailed modelling for the District of Lancaster is further discussed in Section 4.4. The Environment Agency’s Flood Map provides a consistent picture of flood risk for England and Wales.
83. The Environment Agency’s knowledge of the floodplain is continuously being improved by a variety of studies, detailed models, data from river flow and level monitoring stations, and actual flooding information. They have an ongoing programme of improvement, and updates are made on a quarterly basis.
84. The Flood Map is provided in Figure A, showing a considerable proportion of the urban area (namely Morecambe) at risk from tidal flooding.
4.3 Historical Flooding
85. The dominant mechanism of flooding in the Lancaster District has historically been the sea. Tidal events have been recorded as far back as 1851, with large events also occurring in 1898, 1907, 1927 and 1983. In November 1977, an event estimated to be equivalent to an event expected to occur on average once in every 20 years, resulted in flood damage to over 1300 properties in Morecambe. In more recent times, the coincidence of spring tides and extreme storm conditions on the 26th and 27th February 1990 resulted in overtopping of the coastal and river defences through out Morecambe Bay.
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86. Flood risk within the district is not restricted solely to coastal regions. Fluvial flooding in 2004, 1995, 1983 and 1978 was experienced in Galgate on the River Conder, and in 1991, 1990 and 1983 on the River Keer near the agricultural area of Millhead. Hornby and Wray have been affected by flooding of the River Wenning, most recently in 1995 and also in 1964, whilst the River Lune has not been reported to cause property damages from fluvial sources since 1982. Figure C provides a spatial representation of historical flooding recorded by the Environment Agency.
87. Although there is limited detail available, several properties within the district have been affected historically as result of localised runoff, groundwater flooding and/or failure of the underground sewer system. Discussions have been held with United Utilities to identify areas within the district that are known to have been exposed to surface and sewer flooding in recent years (Figure D). These are an important reminder that the risk of flooding is not restricted purely to fluvial and tidal flooding. Development control decisions must be made with due consideration to the potential impact that future development may have upon known existing flooding problems if not carefully managed.
4.4 Detailed Hydraulic Modelling
88. A number of detailed flooding investigations have been carried out by the Environment Agency throughout the district, including;
• River Keer (from the M6 to it’s outfall at Morecambe Bay) • Back Lane • Whitely Beck (Stoney Lane) • River Conder • River Wenning
89. Flood extents were only available for studies undertaken on the River Wenning, Back Lane and River Keer, and in these instances this more robust information has been used to supersede the somewhat coarse Environment Agency Flood Zone Maps.
90. It should be noted that these detailed hydraulic models assume ‘typical’ conditions within the respective river systems that are being analysed. The predicted water levels will modify if the operating regime of the rivers involved are altered (e.g. engineering works which may be implemented in the future), or the condition of the river channel is allowed to deteriorate.
4.5 Flood Defences
91. Flood defences are typically raised structures that alter natural flow patterns and prevent floodwater from entering property in times of flooding. They are generally categorised as either ‘formal’ or ‘informal’ defences. A ‘formal’ flood defence is a structure that is maintained by its respective owner, regardless of whether it is owned by the Environment Agency. An ‘informal’ flood defence is a structure that has often not been specifically built to retain floodwater, and is not maintained for this specific purpose. Boundary walls and industrial buildings situated immediately adjacent to rivers often act as informal flood defences.
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92. The first significant hard defence of the shoreline was recorded in 1849 in the area immediately north of the Stone Jetty. Investigation also indicates that during the late 1920’s and the 1930’s, large lengths of Morecambe’s sea walls were reconstructed. Following the 1977 storm, a sea wall study resulted in the wave reflection wall scheme. A further major storm in 1983 caused a rethink and a more comprehensive study recommended a major upgrade of defences that became a phased capital programme of works. The scheme incorporated breakwaters, groynes, beach renourishment, rock armour and re-profiling existing defences. It was undertaken in a phased approach with the first phase commencing in March 1989. At that time, the final two phases were proposed, and these are to be completed in autumn 2007. Phase 6 includes rock armour protection to the seawall, two rock breakwaters and improvements to the full length of the promenade between Battery to Whinnysty Lane. Phase 7 entails the placing of sand and cobble beaches between Battery and Regent Road, Northumberland Street and Green Street, Calton Terrace and Broadway and Scalestones Point.
93. To provide flood protection to property affected by flooding from the River Lune, the Environment Agency is currently constructing a walled defence to the south of the river in central Lancaster. This protection works remains under construction at the time of writing (August 2007). This defence will provide protection to areas of central Lancaster, including the Luneside East regeneration project. The project currently benefits from outline planning consent for residential, business and open space development,
94. The majority of formal defences identified are located mainly on the River Lune and along approximately 8km of the Morecambe coastline, as shown in Figure A.
95. Although these raised defences may be formally maintained, it is important to reiterate that the risk of flooding can never be fully removed. There will always be a residual risk of flooding, due to (for example) a more extreme event, changing climatic conditions, a structural failure of the constructed flood defence system or flooding behind the defences due to local runoff or groundwater. It is incumbent on both the Council and developers to ensure that the level and integrity of defence provided within developing areas can be assured for the lifetime of the development.
4.6 Consultation
96. Consultation has formed a key part of the data collation phase for the Lancaster SFRA. The following key stakeholders have been comprehensively consulted to inform the current investigation:
Lancaster City Council
Planning Consulted to identify areas under pressure from development and/or regeneration
Drainage Consulted to identify areas potentially at risk from river flooding and/or urban drainage
Emergency Planning Consulted to identify issues that may be of relevance to the planning of an emergency response to a flooding event within the District
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Environment Agency
The Environment Agency has been consulted to source specific flood risk information to inform the development of the SFRA. In addition, the Environment Agency is a statutory consultee under PPS25 and therefore must be satisfied with the findings and recommendations for sustainable flood risk management into the future. For this reason, the Environment Agency has been consulted during the development of the SFRA to discuss potential flood risk mitigation measures and planning recommendations.
United Utilities
United Utilities is responsible for the management of urban drainage (surface water) and sewerage within the Lancaster District. The underground drainage systems in many towns and cities of England are being progressively upgraded from the Victorian sewers. However, they often remain under capacity and subject to relatively frequent ‘overload’ (i.e. resulting in flooding on the surface).
United Utilities was consulted to discuss the risk of localised flooding associated with the existing drainage/sewer system. Unfortunately the feedback provided was very general in nature, providing simply a summary of the number of recorded incidents per post code (refer Figure D). It is not possible therefore to pinpoint known capacity problems and/or infrastructure at risk of structural failure.
It is highlighted however that issues associated with failures of the underground drainage/sewer systems are typically relatively localised, and should not preclude development. It is important however to ensure that future development does not exacerbate known existing problems. Planning decisions should be made with due consideration to potential sewer capacity problems (to be advised by United Utilities as part of the statutory LDF consultation process), and conditions should be placed upon future development to ensure that these capacity issues are rectified before development is permitted to proceed.
4.7 Topography
97. Within some parts of the district, detailed flood risk mapping has been carried out, providing a robust means of delineating zones of ‘high’, ‘medium’ and ‘low’ risk. In areas that have not been modelled to date, dependence must be placed upon the Environment Agency Flood Zone Map, providing a relatively coarse depiction of flood risk, as explained in Section 4.2 above. Given that this is the case, a ‘sensibility’ check has been carried out within areas in which detailed modelling is currently not available. The primary purpose of this check is to ensure that the adopted Environment Agency Flood Zone Map is generally representative of anticipated flooding conditions.
98. In simple terms, topography provides the basis for a common sense assessment of predicted flood zone extents. Indeed it is important to ensure that the Environment Agency Flood Zone Maps reflect the fact that water flows downhill, and that water levels across the river (i.e. on either bank of the river at the same location) are equal. The Environment Agency LiDAR data has been used to reflect the topography of the district in this instance.
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5 Flood Risk in Lancaster District
5.1 Overview
99. The major urban areas within the Lancaster District are concentrated largely along the coastal corridor. These include Heysham, Morecambe, Hest Bank, Slyne, Bolton-le- Sands, Carnforth, Silverdale and Lancaster. Inland, the district is more rural in character with smaller market towns including Galgate, Hornby, Caton, Brookhouse and Wray.
100. Tidal flooding has affected the District numerous times within the past 100 years. Whilst fluvial flooding is less extensive, five flood events have been recorded over the past 20 years. Substantial investment has been made in recent years in an endeavour to alleviate the risk of flooding, including (but not limited to) the Morecambe Coastal Works Scheme and the River Lune flood protection works, improving the standard of protection provided to properties within the District.
101. It is essential to recognise however that the fluvial and coastal flood defences in the district do not fully remove the risk of flooding to properties. In many areas, there is a risk to properties situated behind the defences as a result of groundwater flooding, exacerbated by high river and/or tide levels. Localised flooding as a result of local catchment runoff and/or sewer system failure following heavy rainfall is also a known risk to properties in defended areas.
102. In addition to the River Lune, a risk of flooding has also been identified in association with its tributaries, including the River Wenning, River Conder, River Hindburn, Burrow Beck and Overton Dyke (refer Figure A). The River Keer, outwith the Lune catchment, also pose a potential risk of flooding to the area of Carnforth.
103. These rivers and drains are far more susceptible to ‘flashier’ flooding as a result of localised intense rainfall. With changing climate patterns it is expected that intense storms will become increasingly common. It is vitally important that planning decisions recognise the potential risk that these watercourses pose to property, and that development is planned accordingly so that future sustainability can be assured.
104. The Lancaster Canal runs along the western edge of the River Lune catchment, with the River Conder feeding the canal through a side weir. There is a potential risk posed by a breach in the canal substructure, particular at raised locations. No reports of flooding to or from the canal have been identified.
105. Finally, the overloading of the sewer system due to inflows exceeding the underground system capacity (i.e. resulting in surcharging) is a known problem in some areas.
106. In summary, there are a number of potential sources of flood risk affecting properties within the Lancaster District. Flooding can affect lives and livelihoods, and it is absolutely essential that future development (particularly residential development) is not placed within areas of the District within which the safety of residents cannot be assured in times of flood.
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5.2 Delineation of the PPS25 Flood Risk Zones
107. A key outcome of the SFRA process is the establishment of the Sequential Test in accordance with Appendix D (Table D1) of PPS25. To inform the planning process, it is necessary to review flood risk across the area, categorising the area in terms of the likelihood (or probability) that flooding will occur.
108. The Lancaster District has been delineated into the flood zones summarised below.
Zone 3b The Functional Floodplain Areas of the region susceptible to fluvial flooding within which “water has to flow or be stored in times of flood” (PPS25).
Zone 3a High Probability Land assessed as having a 1 in 100 or greater annual probability (i.e. 1% AEP) of river flooding, or a 1 in 200 or greater annual probability (i.e. 0.5% AEP) of tidal flooding, in any year.
Zone 2 Medium Probability Land assessed as having between a 1 in 100 (i.e. 1% AEP) fluvial or 1 in 200 (i.e. 0.5 % AEP) tidal, and 1 in 1000 (i.e. 0.1% AEP) annual probability of flooding (from fluvial and/or tidal flooding) in any year.
Zone 1 Low Probability Land assessed as having a less than 1 in 1000 annual probability of flooding in any year (i.e. 0.1% AEP).
109. The delineation of the PPS25 flood zones is discussed in Section 5, and presented in the adjoining Flood Risk Maps.
5.2.1 Delineation of Zone 3b Functional Floodplain
110. Zone 3b Functional Floodplain is defined as those areas in which “water has to flow or be stored in times of flood”. The definition of functional floodplain remains somewhat open to subjective interpretation, however for the purposes of the Lancaster SFRA, Zone 3b has been defined in the following manner:
¾ land where the flow of flood water is not prevented by flood defences or by permanent buildings or other solid barriers from inundation during times of flood; ¾ land which provides a function of flood conveyance (i.e. free flow) or flood storage, either through natural processes, or by design (e.g. washlands and flood storage areas); ¾ land subject to flooding in the 4% AEP (25 year) flood event (i.e. relatively frequent inundation expected, on average once every 25 years).
111. Detailed modelling results, and a detailed review of valley topography (in conjunction with a site walkover) in other areas, were used to determine areas that would satisfy the above criteria. Within the District of Lancaster, this encompasses primarily those low lying areas immediately adjoining the River Lune and its tributaries. Any development within these areas is likely to measurably impact upon the existing flooding regime, increasing the severity and frequency of flooding elsewhere. 112. In some areas along the River Lune corridor, it is evident that existing urban areas are affected by flooding in the 5% AEP (20 year) flooding event. The recent release of the PPS25 Practice Companion Guide highlights the importance of considering existing land use when delineating areas that are to be treated as ‘functional floodplain’ for planning purposes.
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113. Discussions with the Environment Agency have confirmed that, due to the obstructions to overland flow paths posed by existing development within flood affected areas, existing buildings (that are impermeable to floodwater) should not be considered as falling within the functional floodplain. The land surrounding existing buildings form important flow paths and flood storage areas however. These must be protected, and planning decisions should be taken accordingly. For this reason, a sub-delineation within Zone 3b has been provided, making reference to ‘developed’ and ‘undeveloped’ areas as described in Section 6.4 below.
114. It is important to recognise that all areas within Zone 3b are subject to relatively frequent flooding – on average, flooding once in every 20 years. There are clear safety, sustainability and insurance implications associated with future development within these areas, and informed planning decisions must be taken with care. This is reflected in the recommended development control conditions outlined below.
5.2.2 Delineation of Zone 3a High Probability
115. Zone 3a High Probability is defined as those areas of the District that are situated below (or within) the 1% AEP (100 year) fluvial flood extent, or the 0.5% (200 year) tidal flood extent.
116. For planning purposes, the Environment Agency has issued a series of Flood Zone Maps as depicted on the Environment Agency’s website (www.environment-agency.gov.uk). As outlined in Section 4, for the reaches of the River Keer, Back Lane, and the River Wenning, these maps have been updated based on detailed modelling that has been carried out on behalf of the Environment Agency.
117. In those areas for which detailed flood mapping is not available (i.e. River Lune), the Environment Agency’s Flood Zone Maps have been adopted to underpin the SFRA process.
5.2.3 Delineation of Zone 2 Medium Probability
118. Zone 2 Medium Probability is defined as those areas of the District that are situated between the 0.1% AEP (1 in 1000 year) and the 1% AEP (1 in 100 year) fluvial flood extents and 0.5% AEP (1 in 200 year) tidal flood extents. In this instance, Zone 2 Medium Probability is defined in accordance with the Environment Agency Flood Zone Map.
119. It is noted that, given the relatively rapid rise in topography at the periphery of the floodplain, the increase in the predicted flood extents between Zone 3a High Probability and Zone 2 Medium Probability is marginal. Consequently, throughout much of the area, the difference in the FZM3 and FZM2 flood extents is limited.
120. An important consideration within Zone 2 Medium Probability is that of critical infrastructure. Figure E presents the location of major hospitals, fire stations and police stations within the Lancaster District. It demonstrates that the majority of Lancaster District’s critical infrastructure is located outside Zone 2 Medium Probability. A fire brigade and a hospital located in Morecambe are at risk of flooding in a 1 in 200 year tidal flood event.
5.2.4 Delineation of Zone 1 Low Probability
121. Zone 1 Low Probability is defined as those areas of the District that are situated above (or outside of) the 0.1% AEP (1000 year) flood extent. For SFRA purposes, this incorporates all land that is outside of the shaded Zone 2 and Zone 3 flood risk areas (as defined above).
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5.3 Assessment of Risk to Life (Flood Hazard)
5.3.1 Definition of Flood Hazard
122. The assessment of flood risk has thus far considered the maximum extent to which flooding will occur during a particular flood event. This provides the basis for assessing broadly the areas potentially impacted by flooding. Of equal importance however is the speed with which flooding occurs as river levels rise. The inundation of floodwaters into low lying areas can pose a considerable risk to life. 123. Substantial research has been carried out internationally into the risk posed to pedestrians during flash flooding. This research has concluded that the likelihood of a person being knocked over by floodwaters is related directly to the depth of flow, and the speed with which the water is flowing. This is referred to as ‘Flood Hazard’. 124. For example, if a flood flow is relatively deep but is low energy (i.e. slow moving), then an average adult will be able to remain standing. Similarly, if the flow of water is moving rapidly but is very shallow, then once again an average adult should not be put off balance. If however the flow is both relatively deep and fast flowing, then a person will be washed off their feet, placing them at considerable risk. The risk to health and safety as a result of submerged hazards during flooding conditions (given the often murky nature of floodwaters) is also a consideration.
125. Defra and the Environment Agency have recently collaborated to develop a document entitled ‘Flood Risk to People’ (FD2320 and FD2321). This provides guidance to aid in the review of flood hazard within the UK. Future detailed site based Flood Risk Assessments should make reference to this document when assessing the potential risk to life posed by flooding (and flood defence failure) as outlined below.
5.3.2 Flood Hazard due to Overbank (Overland) Flooding in Lancaster District
126. The speed and depth with which the both fluvial and tidal floods inundate the Lancaster District is an important consideration. Deep, fast flowing water may potentially pose risk to life. This must be considered when planning future development.
127. It has been assumed that the ‘high flood hazard zone’ is assessed in accordance with Defra “Flood Risk to People” (FD2321), defined as a product of the flow depth and the velocity of the floodwater. Typically, the ‘high flood hazard zone’ areas are particularly evident where floodwaters bypass natural meanders in the river channel, resulting in either deep water and/or high velocities.
128. The lower reaches of the River Lune are contained in a well defined floodplain, and hence development in areas subject to flooding is generally minimal. A review of fluvial flood extents within the Lancaster District corroborates that only small pockets of residential properties are at risk of flooding in a 100 year event. A qualitative review of the River Lune and it’s tributaries within this area highlights the absence of tight bends in the river across which deep, fast flowing water would be expected to break out and flow overland in times of flood. It is reasonable therefore to assume that the potential hazard to life as a result of river ‘break outs’ is minimal.
129. Furthermore, the likelihood of a rapid river level rise within the River Lune and it’s tributaries (resulting in the possible rapid inundation of urban areas) is considered to be small. This is primarily due to the large size of the River Lune and its substantial upper contributing catchment area which allows the Environment Agency, with its current flood warning system, to provide substantial forewarning of a pending flood event to the urban area of Lancaster. It should be noted that the Environment Agency endeavours to meet its flood warning targets but this cannot be guaranteed.
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130. Finally, the velocity of tidal water in Morecambe Bay has been described as ‘faster than a man can run’. Whilst the District is heavily defended against tidal flooding, should these defences over time deteriorate, flood depths of up to 1m within lower lying areas could be expected. This may pose a risk to life, however this has been mitigated to some degree by the construction of raised defences. It is important that the integrity of the defence system is assured over the longer term.
5.3.3 Flood Hazard due to Flood Defence Failure
131. A number of raised defences have been identified within the District of Lancaster, providing protection against tidal flooding within Morecambe, and reducing the risk of river flooding from the River Lune within the Luneside area of Lancaster. Flood defences are typically raised structures that alter natural flow patterns and prevent floodwater from entering property in times of flooding.
132. There is always a residual risk that these defences may fail, as a result of either overtopping and/or breach failure. The latter could result in rapid inundation into overbank areas behind the defence, posing a potential risk to residents, pedestrians and property that may be in the path of the floodwaters.
133. The existing flood defences are generally not situated immediately adjacent to existing and/or proposed urban development and are a level considered unlikely to cause a catastrophic flood wave if a breach were to occur. As a result, the likelihood of a pedestrian standing immediately behind the raised flood defence during flooding conditions is considered small. For this reason, the issue of potential flood hazard due to flood defence failure will not affect the planning considerations informed by this SFRA.
134. Notwithstanding this, the structural integrity of the existing flood defences is absolutely integral to the sustainability of both existing and future development in Luneside and Morecambe. Without the raised defences, the severity and frequency of flooding in these areas will increase. It is essential that the detailed site based Flood Risk Assessment for all potential future development in defended areas of the District considers both the likelihood and consequence of defence failure in the vicinity of the site.
5.4 Coastal Flooding
135. Quite a considerable proportion of the existing urban area within the District of Lancaster is situated within close proximity of the sea. Historically, a large number of homes within the District were at risk of flooding from the sea, with tidal flooding observed as recently as 1990. Based upon current sea level predictions within Morecambe Bay, it is estimated that a substantial area of Morecambe is potentially at risk from tidal flooding on average once in every 5 years.
136. Substantial investment has been made in flood defence to reduce the direct risk posed to homes and business within Morecombe in recent years, and currently a 0.5%(200 year) standard of protection is provided. It is inevitable however that, with the predicted rate of sea level rise associated with global warming, the level of protection provided will reduce over time. It is essential that investment is committed in the long term, not only to ensure that the raised defences are structurally sound (thereby reducing the potential risk of catastrophic failure), but that ultimately the defences are raised to meet rising sea levels.
5.5 Local Drainage Issues
137. As discussed in Section 4.6, consultation has been carried out with the Environment Agency and the Council to identify known and/or perceived problem areas. These drainage problems may be attributed to inundation from floodwaters from open drains and watercourses and increased overland flow due to development and/or exceptionally wet weather. In some instances these problems may be due to poor maintenance, associated with (for example) culvert blockages. These issues are typically both minor and localised in nature.
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138. Within the urban centres of the District, it is inevitable that localised flooding problems arising from under capacity drainage and/or sewer systems will occur. Input has been sought from United Utilities to pinpoint known and/or perceived problem areas, however the information provided is very general. Issues of this nature however, in addition to those outlined above, are generally localised problems that can be addressed as part of the design process. They should therefore not influence the allocation of land for future development.
139. It is essential to ensure that future development does not exacerbate existing flooding problems. Strict planning conditions should be placed upon developers to ensure that best practice measures are implemented to mitigate any potential increase in loading upon existing drainage system(s).
140. The Environment Agency strongly advocates the use of Sustainable Drainage. A wide variety of SUDS techniques are available (refer Section 6.6.3), potentially providing both water quality and water quantity improvement benefits on a site by site basis throughout the District. Wherever possible within brownfield areas, the developer should seek to reduce the rate of runoff from the site to greenfield runoff rates (i.e. the rate of runoff generated from the site assuming an open grassed area). Collectively, the effective application of SUDS as part of all future development will assist in reducing the risk of flooding to the District.
5.6 Groundwater Issues
141. The risk of groundwater flooding is highly variable and heavily dependent upon local conditions at any particular time. Groundwater flooding within the District should therefore not normally preclude development. Notwithstanding this however, it is recognised that the risks associated with groundwater flooding are not well understood, and it is important to ensure that future development is not placed at unnecessary risk.
142. The majority of the District of Lancaster is located within the River Lune catchment. The River Lune CFMP Inception Report details that no instances of groundwater flooding have been identified within the catchment area. Notwithstanding this however, in accordance with PPS25, all future development will require an appropriate Flood Risk Assessment (FRA) at the planning application stage, commensurate with the level of flood risk posed to the site. The detailed FRA should incorporate a detailed site based assessment of the potential risk of groundwater flooding to the site. The adopted design should be established accordingly, mitigating both the risk of groundwater flooding to the development itself, and the potential increase in flood risk posed to adjoining properties as a result of the proposed development.
5.7 Water Supply Infrastructure Failure
143. United Utilities is responsible for water supply infrastructure located within (and adjacent to) the District of Lancaster. Discussions have not identified any infrastructure that may pose a potential risk of flooding should a catastrophic structural failure occur (e.g. a raised reservoir).
5.8 Climate Change 144. A considerable amount of research is being carried out worldwide in an endeavour to quantify the impacts that climate change is likely to have on flooding in future years. Climate change is perceived to represent an increasing risk to low lying areas of England, and it is anticipated that the frequency and severity of flooding will change measurably within our lifetime.
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145. Climate change will influence the District of Lancaster in a number of ways: ¾ increasing sea levels, and thereby increasing the risk of tidal flooding; ¾ increasing rainfall intensity and hence the volume and magnitude of river flows (leading to an increase in the risk of fluvial flooding); and ¾ increasing the frequency and intensity of local storm events (exacerbating localised flooding incidents). 146. Existing and proposed development throughout the District will be affected by at least one of these potential impacts of climate change, and it is imperative that the planning process considers how this may influence future sustainability in the long term. The Impact of Climate Change upon Fluvial Flooding 147. PPS25 (Appendix B) states that a 10% increase in the 1% AEP (100 year) river flow can be expected within the next 20 years, increasing to 20% within the next 100 years. In the absence of detailed modelling to predict the increase in extent that this increase in flow may have upon the river systems within Lancaster, in simple terms the anticipated extent of the 1% AEP (100 year) flood affected area in 2106 can be approximated by the current 0.1% AEP (1000 year) flood outline, i.e. Zone 2 Medium Probability. The Impact of Climate Change upon Tidal Flooding
148. In tidally affected areas within the north west of England, an increasing rate of change in predicted sea levels is to be assumed with time, as summarised in the table below.
Recommended Contingency Allowances for Net Sea Level Rise North West of England (applied to 1990 base sea level) PPS25 (Appendix B) Table B1
1990 to 2025 2025 to 2055 2055 to 2085 2085 to 2115
2.5mm/yr 7.0mm/yr 10.0mm/yr 13.0mm/yr
149. A simple quantitative analysis of climate change to tidal flooding was undertaken at Heysham to assess the relative impact on the Lancaster District coastline. Adopting an average allowance of 4mm per year for sea level rise, after a 50 year time period an extreme water level rise of 200mm is predicted.
150. In terms of the change in flood extent, this increase in sea level can be assumed to be almost exactly equivalent to the difference between the current Zone 3a and Zone 2 outlines as provided in the adjoining flood maps. Once again, it is clear that the change in flood extent (and therefore the increase in the number of properties falling within Zone 3a High Probability) is marginal. The Impact of Climate Change upon Localised Flooding 151. It is emphasised that the potential impacts of climate change will affect not only the risk of flooding posed to property as a result of river flooding, but it will also potentially increase the frequency and intensity of localised storms over the District. This may exacerbate localised drainage problems. It is important therefore that both the site based detailed Flood Risk Assessment and the Surface Water Flood Risk Assessment (i.e. prepared by the developer at the planning application stage as outlined in Section 6) take due consideration of climate change.
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Lancaster District Council Planning Response 152. In planning terms, it is essential that Lancaster City Council consider their response to the potential impacts of climate change within the District. It is clear that climate change will not markedly increase the extent of flooding, and therefore few areas that are currently situated outside of Zone 3 High Probability will be at risk of flooding in future years. This is an important conclusion from a spatial planning perspective. Notwithstanding this however, those properties (and areas) that are currently at risk of flooding may be susceptible to more frequent, more severe flooding in future years. It is essential therefore that the development control process (influencing the design of future development within the District) carefully mitigates against the potential impact that climate change may have upon the risk of flooding to the property. 153. For this reason, all of the development control recommendations set out in Section 6.4 below require all floor levels, access routes, drainage systems and flood mitigation measures to be designed with an allowance for climate change. This provides a robust and sustainable approach to the potential impacts that climate change may have upon the District over the next 100 years, ensuring that future development is considered in light of the possible increases in flood risk over time. 154. It is essential that developers consider the possible change in flood risk over the lifetime of the development as a result of climate change. The likely increase in flow and/or tide level over the lifetime of the development should be assessed proportionally to the guidance provided by the EA as outlined above.
5.9 Residual Risk of Flooding
155. It is essential that the risk of flooding is minimised over the lifetime of the development in all instances. It is important to recognise however that flood risk can never be fully mitigated, and there will always be a residual risk of flooding.
156. This residual risk is associated with a number of potential risk factors including (but not limited to): ¾ a flooding event that exceeds that for which the flood risk management measures have been designed; ¾ the structural deterioration of flood defence structures (including informal structures acting as a flood defence) over time; and/or ¾ general uncertainties inherent in the prediction of flooding.
157. The SFRA process has carried out a review of flood risk within the District of Lancaster in accordance with the PPS25 Sequential Test, identifying a number of areas that fall within Zone 3a High Probability. The modelling of flood flows and flood levels is not an exact science. There are limitations in the methodologies used for prediction, and the models developed are reliant upon observed flow data for calibration, much of which is often of questionable quality. For this reason, there are inherent uncertainties in the prediction of flood levels used in the assessment and management of flood risk.
158. It is difficult to quantify uncertainty. The adopted flood zones underpinning the Lancaster SFRA are based upon the detailed flood mapping within the area adjoining the River Keer, Back Lane and River Wenning, and the Environment Agency flood zone maps in other areas. Whilst these provide a robust depiction of flood risk for specific modelled conditions, all detailed modelling requires the making of core assumptions and the use of empirical estimations relating to (for example) rainfall distribution and catchment response.
159. Taking a conservative approach for planning purposes, it is understood that the Environment Agency (North West Region) generally adopt a 300mm allowance for uncertainty within areas that have been modelled in some detail. The degree of uncertainty in areas reliant upon the Environment Agency’s national generalised computer model will clearly be somewhat higher.
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160. It is incumbent on developers to carry out a detailed Flood Risk Assessment as part of the design process. A review of uncertainty should be undertaken as an integral outcome of this more detailed investigation.
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6 Sustainable Management of Flood Risk
6.1 Overview
161. An ability to demonstrate ‘sustainability’ is a primary government objective for future development within the UK. The definition of ‘sustainability’ encompasses a number of important issues ranging broadly from the environment (i.e. minimising the impact upon the natural environment) to energy consumption (i.e. seeking alternative sources of energy to avoid the depletion of natural resources). Of particular importance however is sustainable development within flood affected areas.
162. Recent history has shown the devastating impacts that flooding can have on lives, homes and businesses. A considerable number of people live and work within areas that are susceptible to flooding, and ideally development should be moved away from these areas over time. It is recognised however that this is often not a practicable solution. For this reason, careful consideration must be taken of the measures that can be put into place to minimise the risk to property and life posed by flooding. These should address the flood risk not only in the short term, but throughout the lifetime of the proposed development. This is a requirement of PPS25.
163. The primary purpose of the SFRA is to inform decision making as part of the planning and development control process, taking due consideration of the scale and nature of flood risk affecting the District. Responsibility for flood risk management resides with all tiers of government, and indeed individual landowners, as outlined below.
6.2 Responsibility for Flood Risk Management
164. There is no statutory requirement for the Government to protect property against the risk of flooding. Notwithstanding this however, the Government recognise the importance of safeguarding the wider community, and in doing so the economic and social well being of the nation. An overview of key responsibilities with respect to flood risk management is provided below.
165. The Regional Assembly should consider flood risk when reviewing strategic planning decisions including (for example) the provision of future housing and transport infrastructure.
166. The Environment Agency has a statutory responsibility for strategic flood management and defence in England. It assists the planning and development control process through the provision of information and advice regarding flood risk and flooding related issues.
167. The Local Planning Authority is responsible for carrying out a Strategic Flood Risk Assessment. The SFRA should consider the risk of flooding throughout the district and should inform the allocation of land for future development, development control policies and sustainability appraisals. Local Planning Authorities have a responsibility to consult with the Environment Agency when making planning decisions.
168. Landowners & Developers3 have the primary responsibility for protecting their land against the risk of flooding. They are also responsible for managing the drainage of their land such that they do not adversely impact upon adjoining properties.
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6.3 Strategic Flood Risk Management - The Environment Agency
6.3.1 Overview
169. With the progressive development of urban areas along river corridors and coastal areas, particularly during the industrial era, a reactive approach to flood risk management evolved. As flooding occurred, walls or embankments were built to prevent inundation to developing areas. Needless to say, construction of such walls should be carefully assessed so that it does not result in the redistribution of floodwater, inadvertently increasing the risk of flooding elsewhere.
170. The Environment Agency (EA) in more recent years has taken a strategic approach to flood risk management. The assessment and management of flood risk is carried out on a ‘whole of catchment’ basis. This enables the Environment Agency to review the impact that proposed defence works at a particular location may have upon flooding at other locations throughout the catchment.
171. A number of flood risk management strategies are underway within the region, encompassing many of the large river systems that influence flood risk within the District of Lancaster. A brief overview of these investigations is provided below.
6.3.2 Catchment Flood Management Plan (CFMP)
172. “One of the Environment Agency’s main goals is to reduce flood risk from rivers and the sea to people, property and the natural environment by supporting and implementing government policies.
173. Flooding is a natural process – we can never stop it happening altogether. So tackling flooding is more than just defending against floods. It means understanding the complex causes of flooding and taking co-ordinated action on every front in partnership with others to reduce flood risk by:
¾ Understanding current and future flood risk; ¾ Planning for the likely impacts of climate change; ¾ Preventing inappropriate development in flood risk areas; ¾ Delivering more sustainable measures to reduce flood risk; ¾ Exploring the wider opportunities to reduce the sources of flood risk, including changes in land use and land management practices and the use of sustainable drainage systems.
174. Catchment Flood Management Plans (CFMPs) are a planning tool through which the Agency aims to work in partnership with other key decision-makers within a river catchment to explore and define long term sustainable policies for flood risk management. CFMPs are a learning process to support an integrated approach to land use planning and management, and also River Basin Management Plans under the Water Framework Directive.”4
175. The fluvial flood risk regime within the District of Lancaster is heavily influenced by the River Lune. CFMPs are developed in a four stage process; inception, scoping, draft CFMP, final CFMP. At the time of writing, only the inception stage report was available for review.
176. The inception report summarises the physical factors of the catchment, such as geology, hydrology, geomorphology and topography. It also listed previous studies within the catchment, and summarises the availability of hydrometric (gauging) data. The inception report summaries information available, providing direction for the scoping study to further investigate the catchment characteristics. The inception report does not provide specific messages for the catchment. This is developed in the draft CFMP stage.
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177. It is noted that the CFMPs are subject to review every 5 years. At this time, any changes made to the CFMP findings and/or recommendations should be incorporated into the SFRA (where relevant).
6.3.3 Shoreline Management Plan (SMP)
178. SMPs provide a large-scale assessment of the risks associated with coastal processes and present a long term policy framework to reduce these risks to people and the developed, historic and natural environment in a sustainable manner. An SMP is a high level document that forms an important element of the strategy for flood and coastal erosion risk management.
179. The specific objectives of the Plan are: ¾ to develop an understanding of the coastal processes operating within the sediment cell or sub-cell and the influence on the shoreline; ¾ to predict the likely future evolution of the coast; ¾ to identify all the assets within the area covered by the Plan which are likely to be affected by coastal change including the developed and natural environment, amenity, leisure facilities and other infrastructure; ¾ to identify means of maintaining and enhancing the natural coastal environment; ¾ to facilitate consultation between those bodies with an interest in the shoreline; ¾ to set objectives for the future management of the shoreline; ¾ to inform the statutory planning process; ¾ to assess a range of coastal defence policy options; ¾ to identify the need for regional or site specify research and investigations; and ¾ to define future monitoring requirements5
180. The Morecambe Bay Shoreline Management Plan (SMP) breaks the coastline into reaches, known as management units. These are defined as ‘a length of shoreline with coherent characteristics in terms of coastal processes and land use’. The Lancaster District encompasses six of these management units between Silverdale to the north and Cockerham Sands to the south.
181. For each management unit, the SMP guidelines require the appraisal of four strategic coastal defence options, from which a preferred option is identified. These strategic options are outlined below:
¾ Do Nothing: A ‘without project’ case where there is no flood or coastal defence activity (i.e. no future maintenance of existing defences) ¾ Hold the existing defence line: To maintain the line of defence in its present position ¾ Advance the existing defence line: To relocate the line of defence seaward of its present position ¾ Retreat the existing defence line: To allow the line of defence to relocate landward of its present position
182. The future management option proposed for the majority of the coastline within Lancaster District is to ‘hold the existing defence line’. To the north of Silverdale (to Hest Bank) several sections recommend a Do Nothing approach in the medium to long term, with some even proposing managed retreat.
183. The above information was provided in the Morecambe Bay SMP, dated March 1999. A revision of the plan is scheduled for 2009. Once the SMP is revised the SFRA should be adjusted to reflect any changes that have been made to the SMP.
5 Morecambe Bay Shoreline Management Plan, Sub-cell 11c: River Wyre to Walney Island, Shoreline Management Partnership, March 1999. September 2007 (Final) 24
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6.3.4 River Basin Management Plan
184. Article 13 of the Water Framework Directive places a duty on member states to ensure that a comprehensive river basin management plan is established. The purpose of the river basin management plan is to set out the pressures, impacts, protected areas and economic information for each basin district. From this, environment objectives, with associated timescales for their achievement, will be established. Within England and Wales the Environment Agency will be given a duty to prepare the draft plan for each district. Plans are to be published by December 2009, with six monthly updates.
185. A River Basin Management Plan (RBMP) is being developed for the River Ribble catchment within the North West of England, and this study will ultimately be adopted as a pilot investigation for other catchments within the region (including the River Lune). The programme of delivery for the River Lune RBMP is currently unknown.
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6.4 Planning & Development Control
6.4.1 Planning Solutions to Flood Risk Management
The Sequential Test
186. Historically urbanisation has evolved along river corridors, the rivers providing a critical source of water, food and energy. This leaves many areas of England with a legacy of key urban centres that, due largely to their close proximity to rivers, are at risk of flooding.
187. The ideal solution to effective and sustainable flood risk management is a planning led one, i.e. steer urban development away from areas that are susceptible to flooding. PPS25 advocates a sequential approach that will guide the planning decision making process (i.e. the allocation of sites). In simple terms, this requires planners to seek to allocate sites for future development within areas of lowest flood risk in the initial instance. Only if it can be demonstrated that there are no suitable sites within these areas should alternative sites (i.e. within areas that may potentially be at risk of flooding) be contemplated.
188. This sequential approach is referred to as The Sequential Test. This is summarised in the flow chart below6.
6 Figure 3.1 (Application of the Sequential Test), A Practice Guide Companion to PPS25, Consultation Paper, February 2007 September 2007 (Final) 26
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It is absolutely imperative to highlight that the SFRA does not attempt, and indeed
cannot, fully address the requirements of the PPS25 Sequential Test. As highlighted in
Section 6.4.1 and the flow chart above, it is necessary for the Council to demonstrate that
sites for future development have been sought within the lowest flood risk zone (i.e. Zone 1
Low Probability). Only if it can be shown that suitable sites are not available within this zone
can alternative sites be considered within the areas that are at greater risk of possible
flooding (i.e. Zone 2, and finally Zone 3).
189. As indicated by the bottom right hand corner of the flow chart above, PPS25 stipulates permissible development types. This considers both the degree of flood risk posed to the site, and the likely vulnerability of the proposed development to damage (and indeed the risk to the lives of the site tenants) should a flood occur.
190. Wherever possible, the Council should restrict development to the permissible land uses summarised in PPS25 Appendix D (Table D2). This may involve seeking opportunities to ‘swap’ more vulnerable allocations at risk of flooding with areas of lesser vulnerability that are situated on higher ground. This is discussed further in Sections 6.4.2 to 6.4.6 below.
The Exception Test
191. It is understood that Lancaster District has a relatively large volume of available land to meet future housing and employment targets, and therefore prohibiting future residential development in these areas is unlikely to have a detrimental impact upon the economic and social welfare of the existing community, however there may be pressing planning ‘needs’ that may warrant further consideration of these areas. Should this be the case, the Council and potential future developers are required to work through the Exception Test (PPS25 Appendix D) where applicable. For the Exception Test to be passed: ¾ “It must be demonstrated that the development provides wider sustainability benefits to the community that outweigh flood risk, informed by a SFRA where one has been prepared. If the DPD has reached the ‘submission’ stage, the benefits of the development should contribute to the Core Strategy’s Sustainability Appraisal; ¾ the development should be on developable, previously developed land or if it is not on previously developed land, that there are no reasonable alternative sites on previously developed land; and ¾ a FRA must demonstrate that the development will be safe, without increasing flood risk elsewhere, and where possible, will reduce flood risk overall.” 192. The first two points set out in the Exception Test are planning considerations that must be adequately addressed. A planning solution to removing flood risk must be sought at each specific location in the initial instance, seeking to relocate the proposed allocation to an area of lower flood risk (i.e. Zone 1 Low Probability or Zone 2 Medium Probability) wherever feasible. 193. The SFRA has been developed in liaison with the Council and the Environment Agency to work through the requirements of the Sequential Test (and, where necessary, the Exception Test) within the District. It will be the responsibility of the developer (in all instances within Zone 3a High Probability) to develop a detailed Flood Risk Assessment that can demonstrate that the Sequential Test has been applied, and (where appropriate) that the risk of flooding has been adequately addressed in accordance with PPS25. It is highlighted that, where the site has been allocated through the LDF process (and therefore sequentially tested) then nothing further is required. In the case of windfall sites however, the developer must work with the Local Authority to ensure that the proposed development site is sequentially tested in accordance with PPS25.
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194. The management of flood risk throughout the District must be assured should development be permitted to proceed, and the SFRA has provided specific recommendations that ultimately should be adopted as planning conditions for all future development. It is the responsibility of the prospective developer to build upon these recommendations as part of a detailed Flood Risk Assessment to ensure that the specific requirements of PPS25 can be met. 195. Specific planning and development control recommendations for future development within the District are presented below. A ‘user guide’ to assist in the application of the SFRA recommendations is provided in Appendix A.
196. An overview of flood risk throughout the District has been provided in Section 6.5 and the adjoining flood risk maps. Future planning decisions should consider the spatial variation in flood risk across the District, as defined by the delineated flood zone that applies at the specified site location, and apply the recommendations provided below accordingly. It is highlighted that PPS25 applies equally to both allocated sites identified within the emerging LDF and future windfall sites.
6.4.2 Future Development within Zone 3b Functional Floodplain (Undeveloped Areas)
Planning Recommendations – Allocation of Land for Future Development Areas of Functional Floodplain that are currently undeveloped should be protected for flood storage purposes. Future development should be restricted to water-compatible uses and essential infrastructure that has to be there (in accordance with PPS25). Careful consideration should be given to the Council’s emergency response in times of flood to ensure that public safety is not compromised.
Development Control Recommendations – Minimum Requirements Future development, with the exception of water compatible uses and essential infrastructure, should not be permitted. The frequency and severity of flooding within these areas are such that no engineered mitigation measures could be implemented to safely and effectively minimise the risk to life and property over the lifetime of the development. It is important to recognise that, in accordance with PPS25, the Exception Test must be satisfied if essential infrastructure is proposed within Zone 3b Functional Floodplain. This will require the submission of a detailed Flood Risk Assessment in accordance with Section 6.6 below.
6.4.3 Future Development within Zone 3b Functional Floodplain (Developed Areas)
It is important to recognise that, within Zone 3b Functional Floodplain, ‘previously developed land’ relates solely to existing buildings that are impermeable to flood water. The land surrounding these buildings are important flow paths and/or flood storage areas that must be retained.
Planning Recommendations – Allocation of Land for Future Development 1. Zone 3b is subject to relatively frequent inundation. There is an aspiration within this zone to reduce the risk posed to life and property, and it is essential therefore that future land uses contribute to achieving this reduction in risk. The intensification of development must be avoided, and permitted land uses should reduce the vulnerability to flooding (in accordance with PPS25 vulnerability categorisations), for example replacing existing residential development (‘more’ vulnerable) with commercial development (‘less’ vulnerable).
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2. In all instances, it will be necessary to ensure that the requirements of the Exception Test are satisfied. In planning terms, it must be demonstrated that “the development provides wider sustainability benefits to the community that outweigh flood risk”. It should be recognised that property situated within Zone 3b Functional Floodplain will be subject to frequent flooding, on average, no less than once in every 20 years. There are clear sustainability implications to be considered in this regard, and it is highly questionable whether insurance against flooding related damages will be available in the longer term. 3. There should be a presumption against all building extensions (including out- buildings) within Zone 3b Functional Floodplain. 4. To satisfy the remaining criteria of the Exception Test, all development within Zone 3b Functional Floodplain (existing developed areas only) should be conditioned in accordance with the development control recommendations below.
Development Control Recommendations – Minimum Requirements 1. A positive reduction in the risk of flooding within the District should be demonstrated as an outcome of the proposed development. This may be achieved through, for example, a reduction in the building footprint area, and/or the realignment of buildings within the site to reduce constrictions to overland flow paths; 2. All proposed future development within Zone 3b Functional Floodplain will require a detailed Flood Risk Assessment (FRA), in accordance with the risk-based approach outlined in Section 6.6 below; 3. Floor levels must be situated above the 1% (100 year) predicted maximum flood level plus climate change, incorporating an allowance for freeboard; 4. Basements are not permitted within Zone 3b Functional Floodplain; 5. Implement SUDS to ensure that runoff from the site (post redevelopment) does not exceed greenfield runoff rates. Any SUDS design must take due account of groundwater and geological conditions; 6. Dry access is to be provided (above flood level) to enable the safe evacuation of residents and/or employees in case of flooding. In exceptional circumstances where this is not achievable, and for non-residential uses, safe access must be provided at all locations, defined in accordance with the emerging Defra research as outlined in “Flood Risk to People” (FD23217). It is essential to ensure that the nominated evacuation route does not divert evacuees onto a ‘dry island’ upon which essential supplies (i.e. food, shelter and medical treatment) will not be available for the duration of the flood event; 7. Ensure that the proposed development does not result in an increase in maximum flood levels within adjoining properties. This may be achieved by ensuring (for example) that the existing building footprint is not increased and/or compensatory flood storage is provided within the site (or upstream)8; 8. A minimum 8m buffer zone must be provided to ‘top of bank’ within sites immediately adjoining the river corridor and/or tidal defences (measured from the landward toe of the defence). Any proposed development within this buffer zone will require Land Drainage consent from the Environment Agency. This requirement may be negotiated with the EA in heavily constrained locations. It is important to recognise that the Environment Agency has permissive powers to carry out maintenance and improvement works along all watercourses that are designated as ‘main rivers. The Council retains this same permissive power for all other watercourses.
7 FD2321 Flood Risk to People, Defra, 2005 8 Compensatory flood storage must be provided on a ‘level for level’ basis (i.e. the loss of available storage volume at each incremental height above river level must be replaced at an equivalent elevation), and must be hydraulically linked to the floodplain so that floodwaters can recede naturally. The Environment Agency can provide further advice in this regard. September 2007 (Final) 29
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6.4.4 Future Development within Zone 3a High Probability
Defended Areas within Zone 3a High Probability A number of properties within the District of Lancaster are situated within Zone 3a High Probability, indicating a potential risk of fluvial and tidal flooding. It is important to recognise however that a considerable proportion of those properties at risk are in fact offered a degree of protection against flooding through the provision of raised defences. Whilst it is recognised that there is a government led commitment to the retention of this system of defences, the statutory responsibility for flood defence remains with the individual landowner. For this reason, all future development must assess (and mitigate) the residual risk of flooding should the defences fail and/or fall into disrepair in future years. A suite of specific development control recommendations have been provided for defended areas, as detailed below. Planning Recommendations – Allocation of Land for Future Development 1. Future development within Zone 3a High Probability should be restricted to ‘less vulnerable’ land uses, in accordance with PPS25 (Appendix D) Table D2. ‘More vulnerable’ land uses, including residential development, should be steered towards zones of lower flood risk (i.e. Zone 2 Medium Probability or Zone 1 Low Probability) within which suitable land may be available in adjoining character areas. 2. Where non-flood risk related planning matters dictate that ‘more vulnerable’ (residential) development should be considered further, it will be necessary to ensure that the requirements of the Exception Test are satisfied. In planning terms, it must be demonstrated that “the development provides wider sustainability benefits to the community that outweigh flood risk”, and that “the development is on developable previously developed land, or that there are no reasonable alternative sites on previously developed land”. 3. To satisfy the remaining criteria of the Exception Test, all development within Zone 3a High Probability should be conditioned in accordance with the development control recommendations below Development Control Recommendations – Minimum Requirements (Undefended Areas) 197. All proposed future development within Zone 3a High Probability will require a detailed Flood Risk Assessment (FRA); 198. Floor levels must be situated above the 1% (100 year) predicted maximum flood level plus climate change, incorporating an allowance for freeboard; 199. Dry access is to be provided (above flood level) to enable the safe evacuation of residents and/or employees in case of flooding. In exceptional circumstances where this is not achievable, and for non-residential uses, safe access must be provided at all locations, defined in accordance with the emerging Defra research as outlined in “Flood Risk to People” (FD23219). It is essential to ensure that the nominated evacuation route does not divert evacuees onto a ‘dry island’ upon which essential supplies (i.e. food, shelter and medical treatment) will not be available for the duration of the flood event; 200. Basements are not to be utilised for habitable purposes. All basements must provide a safe evacuation route in time of flood, providing an access point that is situated above the 1% (100year) peak design plus climate change flood level; 201. Implement SUDS to ensure that runoff from the site (post redevelopment) does not exceed greenfield runoff rates. Any SUDS design must take due account of groundwater and geological conditions;
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202. Ensure that the proposed development does not result in an increase in maximum flood levels within adjoining properties. This may be achieved by ensuring (for example) that the existing building footprint is not increased and/or compensatory flood storage is provided within the site (or upstream)10; 203. A minimum 8m buffer zone must be provided to ‘top of bank’ within sites immediately adjoining the river corridor and/or tidal defences (measured from the landward toe of the defence). Any proposed development within this buffer zone will require Land Drainage consent from the Environment Agency. This requirement may be negotiated with the EA in heavily constrained locations. It is important to recognise that the Environment Agency has permissive powers to carry out maintenance and improvement works along all watercourses that are designated as ‘main rivers. The Council retains this same permissive power for all other watercourses. Development Control Recommendations – Minimum Requirements (Defended Areas) 1. All proposed future development within Zone 3a High Probability will require a detailed Flood Risk Assessment (FRA); 2. Floor levels must be situated above the 1% (100 year) fluvial, or 0.5% (200 year) tidal (whichever is greater), maximum flood level plus climate change, incorporating an allowance for freeboard. The peak design flood levels in this instance should be calculated assuming a breach failure of the River Lune and/or Morecambe tidal flood defences; 3. Implement SUDS to ensure that runoff from the site (post redevelopment) does not exceed greenfield runoff rates. Any SUDS design must take due account of groundwater and geological conditions; 4. Ensure that the proposed development does not result in an increase in maximum flood levels within adjoining properties. This may be achieved by ensuring (for example) that the existing building footprint is not increased and/or compensatory flood storage is provided within the site (or upstream); 5. A minimum 8m buffer zone must be provided to ‘top of bank’ within sites immediately adjoining the river corridor and/or tidal defences (measured from the landward toe of the defence). 6.4.5 Future Development within Zone 2 Medium Probability Planning Recommendations – Allocation of Land for Future Development 1. In accordance with PPS25, land use within Zone 2 Medium Probability should be restricted to the ‘water-compatible’, ‘less vulnerable’ and ‘more vulnerable’ category (including residential development), or essential infrastructure, to satisfy the requirements of the Sequential Test; 2. Where non-flood risk related planning matters dictate that ‘highly vulnerable’ development should be considered further, it will be necessary to ensure that the requirements of the Exception Test are satisfied. In planning terms, it must be demonstrated that “the development provides wider sustainability benefits to the community that outweigh flood risk”, and that “the development is on developable previously developed land, or that there are no reasonable alternative sites on previously developed land”. 3. To satisfy the remaining criteria of the Exception Test, all development within Zone 2 Medium Probability should be conditioned in accordance with the development control recommendations below. Development Control Recommendations – Minimum Requirements 1. All proposed future development within Zone 2 Medium Probability will require a Flood Risk Assessment (FRA) that is commensurate with the risk posed to the proposed development;
10 Compensatory flood storage should be located as close as practically possible to the proposed development. The Environment Agency can provide further advice in this regard September 2007 (Final) 31
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2. Floor levels must be situated above the 1% (100 year) predicted maximum flood level plus climate change, incorporating an allowance for freeboard; 3. Dry access is to be provided (above flood level) to enable the safe evacuation of residents and/or employees in case of flooding. In exceptional circumstances where this is not achievable, and for non-residential uses, safe access must be provided at all locations, defined in accordance with the emerging Defra research as outlined in “Flood Risks to People” (FD2321). It is essential to ensure that the nominated evacuation route does not divert evacuees onto a ‘dry island’ upon which essential supplies (i.e. food, shelter and medical treatment) will not be available for the duration of the flood event; 4. Implement SUDS to ensure that runoff from the site (post redevelopment) does not exceed greenfield runoff rates. Any SUDS design must take due account of groundwater and geological conditions (refer Section 6.6.3)
6.4.6 Future Development within Zone 1 Low Probability
Planning Recommendations – Allocation of Land for Future Development There are generally no flood risk related constraints placed upon land use within Zone 1 Low Probability (in accordance with PPS25), however it is important to recognise that future development within this zone may adversely impact upon the existing flooding regime if not carefully managed. Flooding related issues of a localised nature may also occur within Zone 1 Low Probability. For this reason, all development should be carried out in accordance with the development control recommendation below. Within ‘dry island’ areas that are surrounded by a degree of flood risk, effective emergency planning measures should be in place to ensure that the risk to life is minimised in case of flooding. Development Control Recommendations – Minimum Requirements A simple Flood Risk Assessment will be required in compliance with PPS25 and current guidance and policy. This will involve the introduction of sustainable drainage (SUDS) techniques to ensure that runoff from the site (post redevelopment) are not increased. Any SUDS design must take due account of groundwater and geological conditions.
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6.5 Overview of Flood Risk
6.5.1 General
204. An overview of the flood risk issues that are faced within the Lancaster District is provided within the paragraphs below. This summary is intended to provide an indication of the nature and scale of the flooding risk posed to existing development within the nominated character area. It is also intended to inform decision making with respect to future development, using the information provided below (and in adjoining Figures B1 to B15) and cross referencing this to the recommendations provided in Section 6.4 above. The user guide provided in Appendix A maps out the decision making process required in this regard.
6.5.2 Character Area B1 – Silverdale (Refer Figure B1)
Assessment of Flood Risk
Character Area B1 is subject to both tidal and fluvial flooding. Tidal ZONE 3a HIGH PROBABILITY affects the Morecambe Bay Nature Reserve, with the exception of Shore Cottages. This flood zone is restricted to the undeveloped coastal marshland. Defences do not exist along this coastal stretch.
Isolated patches of ZONE 3a HIGH PROBABILITY (with ZONE 2 MEDIUM PROBABILITY at the periphery) exist along the Myer’s Dike watercourse.
At Waterslack a number of dwellings and a caravan site are located within ZONE 3a HIGH PROBABILITY.
Leighton Moss Nature Reserve is situated within ZONE 3a HIGH PROBABILITY. The remainder of the character area is considered ZONE 1 LOW PROBABILITY and there one recorded localised drainage event.
Overview of Development Pressures
The Core Strategy seeks to concentrate the majority of development within the urban areas of Lancaster, Morecambe, Heysham and Carnforth. However, Silverdale is identified as one of a number of villages within Lancaster District where a small amount of future development (10% of new homes and 5% of employment land) will be made available to serve local needs (Policy SC2). There are no specific areas of development pressure identified within Silverdale
6.5.3 Character Area B2 – Carnforth (Refer Figure B2)
Assessment of Flood Risk
Character Area B2 is subject to fluvial, tidal and sewer flooding.
Carnforth is located where the River Keer enters the tidal marshland at the Kent estuary. The River Keer is therefore subject to the tidal influence of Morecambe Bay in this reach. The River Keer catchment is approximately 50 km2, and it is a relatively flat and largely rural catchment with forest plantations. The geology of the catchment is characterised by limestone, and as a result rainfall can result in significant and often ‘flashy’ runoff into the River Keer. Much of the land within Character Area B2 is subject to flooding from the River Keer.
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Back Lane flows in a northerly direction along the eastern boundary of Carnforth, draining into the River Keer just upstream of Keer Bridge. Back Lane is heavily culverted and requires much maintenance. There are no defences along its length. There are areas of ZONE 3b FUNCTIONAL FLOODPLAIN, ZONE 3a HIGH PROBABILITY and ZONE 2 MEDIUM PROBABILITY associated with Back Lane.
The Lancaster Canal runs through Character Area B2. A thin section of ZONE 2 MEDIUM PROBABILITY runs along the channel of the canal, however no reports of flooding from the canal have been identified. The residual risk of possible structural failure of the canal may exist, however this risk is considered very low. Additionally there are areas of ZONE 2 MEDIUM PROBABILITY associated with Pine Lake reservoir in the north east section of the character area.
Carnforth is an area which has suffered from sewer flooding problems in the past. The localised flooding issues (United Utilities) records identify seven recorded incidents.
The remainder of character area B2 is considered ZONE 1 LOW PROBABILITY.
Overview of Development Pressures
The Core Strategy seeks to develop Carnforth as a successful market town and service centre, encouraging new housing on brownfield sites. Policy ER2 of the Core Strategy identifies Carnforth as a Regeneration Priority Area and will be developed as a rural service centre with the development of large derelict sites, relocation of poorly located uses and new pedestrian links. In this regard, it is identified as one of the main settlements which will provide the majority of development land (Policy SC2 of the Core Strategy).
6.5.4 Character Area B3 – Bolton-le-Sands (Refer Figure B3)
Assessment of Flood Risk
Character Area B3 is predominantly ZONE 1 LOW PROBABILITY.
A strip of ZONE 3a HIGH PROBABILITY exists along the coastal marshland and extends in as far as the railway line in places. Raised coastal defences exist along ‘The Shore’ houses and the caravan site and camping park at Pasture Lane. Additionally there are areas of ZONE 3a HIGH PROBABILITY associated with a tidally influenced Environment Agency maintained minor watercourse in the south west of this character area. In the northern part of Character Area B3, there is an area of ZONE 2 MEDIUM PROBABILITY associated with another minor watercourse that is also maintained by the Environment Agency.
The Lancaster Canal runs through Character Area B3. A thin section of ZONE 2 MEDIUM PROBABILITY runs along the channel of the canal. No reports of flooding to or from the canal have been identified. The residual risk of possible structural failure of the canal may exist, however this risk is considered very low.
There are only minor known localise drainage issues in this area, with 3 reported incidents of sewer flooding received from United Utilities.
Overview of Development Pressures
The Core Strategy seeks to concentrate the majority of development within the urban areas of Lancaster, Morecambe, Heysham and Carnforth. However, Bolton-le-Sands is identified as one of a number of villages within Lancaster District where a small amount of future development (10% of new homes and 5% of employment land) will be made available to serve local needs (Policy SC2). It is anticipated that any development within the village will be located within the urban area. There are no specific areas of development pressure identified within Bolton-le-Sands.
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6.5.5 Character Area B4 – Slyne-with-Hest (Refer Figure B4)
Assessment of Flood Risk
Character Area B4 is located along Morecambe Bay. Tidal ZONE 3a HIGH PROBABILITY exists along the shoreline and stretches further inland in isolated areas, particularly around watercourses.
Hatlex Beck is an Environment Agency maintained channel and the land within close proximity to it is considered predominantly ZONE 3a HIGH PROBABILITY with areas of ZONE 2 MEDIUM PROBABILITY at the periphery of the zone. There is also a series of minor watercourses located in the south of the character area, their associated low lying land enables tidal egress resulting in areas of land falling within ZONE 3a HIGH PROBABILITY in and around Morecambe Golf Course.
The remainder of the character area is considered ZONE 1 LOW PROBABILITY. The records provided by Untied Utilities identify four localised drainage events occurring in the region.
Overview of Development Pressures
The Core Strategy seeks to concentrate the majority of development within the urban areas of Lancaster, Morecambe, Heysham and Carnforth. However, Slyne-with-Hest is identified as one of a number of villages within Lancaster District where a small amount of future development (10% of new homes and 5% of employment land) will be made available to serve local needs (Policy SC2). It is anticipated that any development within the village will be located within the urban area.
6.5.6 Character Area B5 – Morecambe Central and West End (Refer Figure B5)
Assessment of Flood Risk
Character Area B5 for the larger part is considered ZONE 3a HIGH PROBABILITY. Lesser areas of ZONE 2 MEDIUM PROBABILITY and ZONE 1 LOW PROBABILITY exist in isolated patches at higher elevations. Flooding in this area is the result of tidal mechanisms.
Character Area B5 is situated on the Morecambe Bay coastline, and formal raised flood defences extend almost the entire coastline within this character area. Historical records show that in 1977, an event estimated to be equivalent to approximately a 1 in 20 year (5% AEP) flood, inundated more than 1300 properties in Morecambe.
The CFMP inception report has identified flooding from sewers as an issue in this densely urbanised area, whilst the United Utilities identifies only one record in this area.
Overview of Development Pressures
Morecambe is identified as a Regeneration Priority Area of regional importance according to Policy ER2 of the Core Strategy. As a result, the Core Strategy seeks to ensure that Morecambe becomes a confident community with a regenerated living, working and leisure environment and seeks to concentrate the majority of development within the urban areas of Lancaster, Morecambe, Heysham and Carnforth.
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6.5.7 Character Area B6 – White Lund and Luneside (Refer to Figure B6)
Assessment of Flood Risk
Character Area B6 is largely situated within ZONE 3a HIGH PROBABILITY to the north of the River Lune, and to the south is predominantly ZONE 3b FUNCTIONAL FLOODPLAIN. The area is susceptible to flooding from the Lower Lune which is significantly tidally influenced in this reach.
The Lower Lune is known to have resulted in significant tidal storm events in 1907, 1927 and 1977 causing widespread flooding to residential property, industrial units and agricultural land. More recently, lesser events in 1983, 1990 and 1995 have also caused flooding. According to the CFMP inception report, severe bank erosion is evident throughout the Lune catchment. This leads to an increase in sediment and a reduction in channel capacity. Where significant build up of sediment occurs, reductions in the standard of protection at flood risk areas may result.
In 2002 the area in and around the Lune Industrial Estate flooded as a result of defence overtopping, and the Aldcliffe Embankment overtopped. As a result of force 8 winds, combined with tidal and fluvial events, water levels during this event reached 7mAOD (i.e. 7m above ordnance datum) at the Aldcliffe Embankment.
Since the flooding in 2002, flood protection works along the left bank of the River Lune, adjacent to the Lune Industrial Estate, has elevated the area from Zone 3b FUNCTIONAL FLOODPLAIN to Zone 3a HIGH PROBABILITY. This change in zone also enabled the Luneside East development.
There are no known localised drainage issues in this character area, however it is anticipated that flooding from sewers is likely. The area is densely urbanised and the United Utilities records identify several incidents of localised flooding.
Overview of Development Pressures
Character Area B6 is dominated by an area of employment land uses in terms of the White Lund industrial estate (Site 21).
The Core Strategy seeks to concentrate the majority of development within the urban areas of Lancaster, Morecambe, Heysham and Carnforth (Policy SC2). Policy ER2 of the Core Strategy identifies the White Lund as a Regeneration Priority Area and will therefore continue to be the District’s main location for employment uses.
Policy ER2 also identifies the Luneside as a Regeneration Priority Area in terms of mixed use waterfront regeneration which will receive flood defences and remediation.
6.5.8 Character Area B7 – North East Lancaster (Refer to Figure B7)
Assessment of Flood Risk
Character Area B7 is situated on the River Lune. Areas of ZONE 3b FUNCTIONAL FLOODPLAIN, ZONE 3a HIGH PROBABILITY and ZONE 2 MEDIUM PROBABILITY sit within relatively close proximity to the river channel and stretch along the entire length of this character area. Lansil Industrial Estate on the south side of the river is known to have experienced major flooding in 1995, consequently a sub-station was at risk on the south side of the river and army warehouses/camp was at risk on the right bank.
According to the CFMP inception report, severe bank erosion is evident throughout the Lune catchment. This leads to an increase in sediment and a reduction in channel capacity. Where significant build up of sediment occurs, reductions in the standard of protection at flood risk areas may result. It is noted that downstream of Skerton Weir a
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build up of sediments occurs and this may lead to a reduction in the standard of protection.
In the western portion of the character area land drains give rise to small isolated patches of ZONE 3a HIGH PROBABILITY and ZONE 2 MEDIUM PROBABILITY.
The Lancaster Canal runs through Character Area B7 and passes over the River Lune in a 19m high aqueduct constructed in 1797. A thin section of ZONE 2 MEDIUM PROBABILITY runs along the channel of the canal. No reports of flooding to or from the canal have been identified. Although there are no known flooding issues associated with the Lune Aqueduct, it should be noted that a residual risk is posed by any such structure should it fail, and therefore the structural integrity should be maintained to reduce any risk.
The CFMP inception report identifies Skerton as a densely urbanised area that has experienced a large number of sewer flooding events.
The remainder of the character area is considered ZONE 1 LOW PROBABILITY.
Overview of Development Pressures
The Core Strategy seeks to concentrate the majority of development within the urban areas of Lancaster, Morecambe, Heysham and Carnforth (Policy SC2).
Development pressure within Character Area B7 relates mainly to employment land uses along Caton Road and Lancaster Business Park (Site 11) as designated within the adopted Local Plan. Policy ER2 identifies Caton Road as a regeneration priority area. In this regard, a business development zone will be identified and areas close to the M6 will accommodate industries with a demonstrated need for direct motorway access.
6.5.9 Character Area B8 – Halton (Refer to Figure B8)
Assessment of Flood Risk
Character Area B8 is situated on the River Lune. The River Lune gives rise to ZONE 3b FUNCTIONAL FLOODPLAIN, ZONE 3a HIGH PROBABILITY and ZONE 2 MEDIUM PROBABILITY areas within relatively close proximity of the river channel.
The Lune catchment is primarily rural with characteristic limestone geology. Runoff is affected by reservoir storage and public water supply abstraction. The catchment area upstream of Halton is approximately 1000 km2. According to the CFMP inception report, severe bank erosion is evident throughout the Lune catchment. This leads to an increase in sediment load and a reduction in channel capacity. Where significant build up of sediment occurs, reductions in the standard of protection at flood risk areas may result. Discontinuous defences exist along reaches of the Lune within this character area.
The CFMP inception report identifies a pub downstream of Halton Bridge on the northern bank that is subject to flooding as a result of insufficient culvert capacity on Cote Beck. Cote Beck is a minor watercourse that flows in a southerly direction into the Lune and there are small areas of ZONE 3a HIGH PROBABILITY that exist along its length.
The remainder of the character area is considered ZONE 1 LOW PROBABILITY.
Overview of Development Pressures
The Core Strategy seeks to concentrate the majority of development within the urban areas of Lancaster, Morecambe, Heysham and Carnforth. However, Halton is identified as one of a number of villages within Lancaster District where a small amount of future development (10% of new homes and 5% of employment land) will be made available to serve local needs (Policy SC2).
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6.5.10 Character Area B9 – Caton and Brookhouse (Refer Figure B9)
Assessment of Flood Risk
Character Area B9 is located on the River Lune. High flows on the River Lune occupy the wide band of floodplain at Caton. Areas of ZONE 3b FUNCTIONAL FLOODPLAIN, ZONE 3a HIGH PROBABILITY and ZONE 2 MEDIUM PROBABILITY affect areas within relatively close proximity of the river channel.
As described above, the Lune catchment is primarily rural with characteristic limestone geology. Runoff is affected by reservoir storage and public water supply abstraction. The catchment area upstream of Halton is 994.6 km2. According to the CFMP inception report, severe bank erosion is evident throughout the Lune catchment. This leads to an increase in sediment load and a reduction in channel capacity. Where significant build up of sediment occurs, reductions in the standard of protection at flood risk areas may result. Defences exist along reaches of the Lune within this character area.
Artle Beck meanders in a northerly direction through Caton to join the River Lune upstream of the water testing station. There are areas of ZONE 3a HIGH PROBABILITY located in and around the Artle Beck channel. At Forge Bridge the watercourse passes in an aqueduct. The aqueduct is known to have flooded in 1891, 1892, 1903 and there was severe flooding in 1995. Flooding from an aqueduct is considered a flood hazard as it has the potential to pose risk to life.
Tarn Brook flows through Brookhouse into the River Lune upstream of the Artle Beck confluence. An area of ZONE 3a HIGH PROBABILITY exists at the downstream end of the watercourse.
It should be noted that there are a number of minor watercourses in this character area (e.g. Kirk Beck and Escow Beck) that are mapped as ZONE 1 LOW PROBABILITY but should be given consideration when contemplating planning applications.
There are an insignificant number of records of localised drainage issues in this character area. It is however noted that many of the minor watercourses travel in culvert and there may be unknown capacity/blockage issues associated with such structures.
Overview of Development Pressures
The Core Strategy seeks to concentrate the majority of development within the urban areas of Lancaster, Morecambe, Heysham and Carnforth. However, Caton and Brookhouse are identified as one of a number of villages within Lancaster District where a small amount of future development (10% of new homes and 5% of employment land) will be made available to serve local needs (Policy SC2). There are no specific areas of development pressure identified within the settlements.
6.5.11 Character Area B10 – West Lancaster (Refer Figure B10)
Assessment of Flood Risk
Character Area B10 located to the west of Lancaster to the south of the River Lune and is predominantly ZONE 1 LOW PROBABILITY. There are isolated patches of ZONE 3b FUNCTIONAL FLOODPLAIN, ZONE 3a HIGH PROBABILITY and ZONE 2 MEDIUM PROBABILITY surrounding the River Lune to the north west of the character area, and to the south a thin band represents risk from Burrow Beck.
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The Lancaster Canal runs through character area B10. A thin section of ZONE 2 MEDIUM PROBABILITY runs along the channel of the canal. No reports of flooding to or from the canal have been identified. The residual risk of possible structural failure of the canal may exist, however this risk is considered very low.
The CFMP inception report identifies the area in and around the densely urbanised Moorlands as areas of historical sewer flooding, and the United Utilities records identify three events.
The remainder of the character area is considered ZONE 1 LOW PROBABILITY.
Overview of Development Pressures
The Core Strategy seeks to concentrate the majority of development within the urban areas of Lancaster, Morecambe, Heysham and Carnforth (Policy SC2).
6.5.12 Character Area B11 – East Lancaster (Refer Figure B11)
Assessment of Flood Risk
Character Area B11 is situated on Burrow Beck to the south of Lancaster. Burrow Beck flows south easterly through the settlement of Scotforth. A thin band of ZONE 3b FUNCTIONAL FLOODPLAIN, ZONE 3a HIGH PROBABILITY and ZONE 2 MEDIUM PROBABILITY exists along the Burrow Beck channel. There are no formal raised defences present within this character area.
The Lancaster Canal runs through character area B11. A thin section of ZONE 2 MEDIUM PROBABILITY runs along the channel of the canal. No reports of flooding to or from the canal have been identified. The residual risk of possible structural failure of the canal may exist, however this risk is considered very low.
The remainder of the character area is considered ZONE 1 LOW PROBABILITY.
Overview of Development Pressures
The Core Strategy seeks to concentrate the majority of development within the urban areas of Lancaster, Morecambe, Heysham and Carnforth. Scotforth is located within the southern part of Lancaster.
The Character Area is located to the south of Lancaster with a number of sites being the subject of previous consideration for residential development within an early consultation draft of the Lancaster District Local Plan (Sites 7-9). These sites are not allocated for development in the adopted local plan.
6.5.13 Character Area B12 – Lancaster University (Refer Figure B12)
Assessment of Flood Risk
Character Area B12 is situated on the River Conder to the south east of the River Lune.
Areas of ZONE 3b FUNCTIONAL FLOODPLAIN, ZONE 3a HIGH PROBABILITY and ZONE 2 MEDIUM PROBABILITY exist along the River Condor corridor. There are defences but they provide a low standard of defence and are of poor condition hence have not been represented.
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The River Condor catchment is generally underlain by characteristically clay geology. Flooding occurred on the River Conder in 1995 and 1998. Several houses were inundated and walls had to be demolished to allow water to make its way back into the channel in August 2004. It is perceived that this flooding resulted from the construction of the University and the failure of ‘holding ponds’ on the south campus. At Galgate the River Conder is crossed by small bridges and pipe crossings, this is considered an obstruction risk.
Whitley Beck is a minor watercourse that flows relatively parallel to the River Conder and merges with it at Galgate. At Stoney Lane, Whitley Beck enters a culvert. In October 1998, flooding of 21 properties resulted from this culvert being almost fully blocked with debris that had become lodged on a pipe crossing.
Ou Beck is a small watercourse that flows in a southerly direction across farmland and under the Lancaster Canal before joining the River Conder. The CFMP inception report identifies the small watercourse of Ou Beck as posing a severe threat as it is heavily culverted. Maintenance is necessary to clear Ou Beck culverts and therefore reduce the risk of flooding. A siphon under the Lancaster Canal is known to present a blockage risk for the Ou Beck watercourse.
The Lancaster Canal runs through character area B12. A thin section of ZONE 2 MEDIUM PROBABILITY runs along the channel of the canal. No reports of flooding to or from the canal have been identified. The residual risk of possible structural failure of the canal may exist, however this risk is considered very low.
The remainder of the character area is considered ZONE 1 LOW PROBABILITY.
Overview of Development Pressures
The Character Area is dominated by Lancaster University (Site 10). Policy ER1 states that the Council will support the continued expansion of the University within the existing built-up area.
6.5.14 Character Area B13 – Hornby (Refer Figure B13)
Assessment of Flood Risk
Character Area B13 is situated at the confluence of the River Wenning and the River Hindburn just upstream of where they join the River Lune. Areas of ZONE 3b FUNCTIONAL FLOODPLAIN, ZONE 3a HIGH PROBABILITY and ZONE 2 MEDIUM PROBABILITY exist around the River Lune, Wenning, Hindburn and a smaller watercourse that passes through Wray. Defences exist on the River Wenning adjacent to Hornby.
The 230km2 catchment of the River Wenning is generally underlain by limestone. In 1964 severe flooding of the River Wenning is known to have occurred. Upstream of this character area at High Bentham the flood of 1964 washed away a weir below the Wenning Bridge, which formed a swimming pool and a huge gravel beach. On the 31 January 1995 the River Wenning overtopped, exceeding channel capacity on both the left and right bank at Hornby (maximum recorded level was 25.1m AOD). The result in Hornby was that Old Smithy, Main Street, Car Park and Sewage Works were flooded. Approximately 20-30 properties were damaged in the 1995 event and a new flood alleviation scheme was introduced as a result.
Wray is known to have flooded in 1967. Debris blocked a bridge and the bridge and houses were washed away. This severe event was caused by a very intensive storm in which over 110mm of rain fell in a 90 minute period (Orr and Carling, 2006), equating to approximately a 1 in 2000 year event (CFMP inception report).
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Overview of Development Pressures
The village of Hornby is located within Character Area B13. Policy SC3 of the Core Strategy relates to rural communities and seeks to protect, conserve and enhance the character of remote villages whilst provide for local housing and employment uses. There are no specific areas within Character Area B13 which are under development pressure.
6.5.15 Character Area B14 –Heysham (Refer Figure B14)
Assessment of Flood Risk
Character Area B14 is located on Morecambe Bay coast by Heysham Harbour. The area is predominantly ZONE 1 LOW PROBABILITY.
In the eastern portion the character area is considered ZONE 3a HIGH PROBABILITY due to the Lower Lune which is tidally influenced in this reach, and various land drains/minor watercourses.
Adjacent to the Lower Lune at Lancaster, it is known that significant tidal storm events in 1907, 1927 and 1977 caused widespread flooding to residential property, industrial units and agricultural land. More recently, lesser events in 1983, 1990, 1995 and 1977 have also caused flooding.
The western portion of the character area there are areas of tidal ZONE 3a HIGH PROBABILITY and ZONE 2 MEDIUM PROBABILITY. These areas are confined to Heysham Sands and small areas of Heysham Harbour. No coastal defences exist in this character area.
The CFMP inception report describes the densely urbanised areas of Heysham as an area of historical sewer flooding. The United Utilities record identifies a significant number of records in this area.
The remainder of the character area to is predominantly ZONE 1 LOW PROBABILITY.
Overview of Development Pressures
The Character Area is dominated by Heysham Power Station (Site 27) and the port and Industrial Estate (Site 26) which are located to the south west of the town. These sites are the subject of continual redevelopment.
6.5.16 Character Area B15 –Middleton (Refer Figure B15)
Assessment of Flood Risk
Character Area B15 lies on the coast at Middleton. Areas of coastal ZONE 3a HIGH PROBABILITY are generally restricted to Middleton Sands.
Lades Pool and a series of other overland drains and minor watercourses exist which give rise to ZONE 3a HIGH PROBABILITY and smaller areas of ZONE 2 MEDIUM PROBABILITY.
The remainder of the character area is considered ZONE 1 LOW PROBABILITY.
Few records from the United Utilities indicate that limited localised drainage issues are evident within this character area.
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Overview of Development Pressures
Within the Character Area there are industrial estates and business parks which are the subject of redevelopment proposals (Sites 28-31).
In addition, a former holiday camp (Site 32) is being redeveloped as a retirement village for approximately 600 dwellings.
6.5.17 Remaining Areas of the District
205. All remaining areas are situated on higher ground within Zone 1 Low Probability, and/or are not subject to any future development pressures. Some localised drainage and/or groundwater issues may exist, however these should not preclude future development.
206. There are no flood risk related constraints placed upon land use within Zone 1 Low Probability (in accordance with PPS25). Notwithstanding this, a simple Flood Risk Assessment will be required in compliance with PPS25 and current guidance and policy. This will involve the introduction of SUDS techniques. Any SUDS design must take due account of groundwater and geological conditions.
6.5.18 PPS25 Constraints upon Emerging Site Allocations
207. A review of the emerging housing and employment allocations has been carried out. The risk of flooding posed to each site has been assessed (i.e. based upon the delineated flood zone within which the site falls), and the Sequential Test applied to identify the planning constraints posed by PPS25 accordingly. A ‘traffic light’ system has been adopted to summarise the preferred land use for each site (i.e. in strict accordance with the Sequential Test), restricted land uses (i.e. those not permitted under PPS25), and permissible land uses that may be considered if the Exception Test can be satisfied. This analysis is presented as Appendix B.
6.6 Detailed Flood Risk Assessment (FRA) – The Developer
6.6.1 Scope of the Detailed Flood Risk Assessment
208. As highlighted in Section 2, the SFRA is a strategic document that provides an overview of flood risk throughout the area. It is imperative that a site-based Flood Risk Assessment (FRA) is carried out by the developer for all proposed developments, and this should be submitted as an integral part of the planning application.
209. The FRA should be commensurate with the risk of flooding to the proposed development. For example, where the risk of flooding to the site is negligible (e.g. Zone 1 Low Probability), there is little benefit to be gained in assessing the potential risk to life and/or property as a result of flooding. Rather, emphasis should be placed on ensuring that runoff from the site does not exacerbate flooding lower in the catchment. The particular requirements for FRAs within each delineated flood zone are outlined below.
It is highlighted that the description of flood risk provided in the Character Area discussions above places emphasis upon the two predominant sources of flood risk (i.e. the River Lune and Morecambe Bay). In all areas, a localised risk of flooding may also occur, typically associated with local catchment runoff following intense rainfall passing directly over the District. This localised risk of flooding must also be considered as an integral part of the detailed Flood Risk Assessment.
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210. Proposed Development within Zone 3a High Probability & Zone 3b Functional Floodplain
All FRAs supporting proposed development within Zone 3b Functional Floodplain and Zone 3a High Probability should include an assessment of the following:
¾ The vulnerability of the development to flooding from other sources (e.g. surface water drainage, groundwater) as well as from river flooding. This will involve discussion with the Council and the Environment Agency to confirm whether a localised risk of flooding exists at the proposed site.
¾ The vulnerability of the development to flooding over the lifetime of the development (including the potential impacts of climate change), i.e. maximum water levels, flow paths and flood extents within the property and surrounding area. The Environment Agency may have carried out detailed flood risk mapping within localised areas that could be used to underpin this assessment. Where available, this will be provided at a cost to the developer. Where detailed modelling is not available, hydraulic modelling by suitably qualified engineers will be required to determine the risk of flooding to the site.
¾ The potential of the development to increase flood risk elsewhere through the addition of hard surfaces, the effect of the new development on surface water runoff, and the effect of the new development on depth and speed of flooding to adjacent and surrounding property. This will require a detailed assessment, to be carried out by a suitably qualified engineer.
¾ A demonstration that residual risks of flooding (after existing and proposed flood management and mitigation measures are taken into account) are acceptable. Measures may include flood defences, flood resistant and resilient design, escape/evacuation, effective flood warning and emergency planning.
¾ Details of existing site levels, proposed site levels and proposed ground floor levels. All levels should be stated relevant to Ordnance Datum.
211. It is noted that a proportion of the District of Lancaster is delineated as Zone 3a High Probability, however the presence of localised raised defences provides a degree of protection against flooding. It is broadly accepted that these defences reduce the actual risk to properties. However recent history has demonstrated that the residual risk remains with potentially catastrophic consequence of a breach failure, often resulting in widespread flooding.
212. It is essential that developers thoroughly review the existing and future structural integrity of the defences (i.e. over the lifetime of the development), and ensure that emergency planning measures are in place to minimise risk to life in the unlikely event of a defence failure.
213. Proposed Development within Zone 2 Medium Probability (1% (100 year) including climate change)
For all sites within Zone 2 Medium Probability, a high level FRA should be prepared based upon readily available existing flooding information, sourced from the EA. It will be necessary to demonstrate that the residual risk of flooding to the property is effectively managed through, for example, the provision of raised floor levels (refer Section 6.6.2) and the provision of a planned evacuation route and/or safe haven.
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214. Proposed Development within Zone 2 Medium Probability and Zone 1 Low Probability
Within all areas of the District, the risk of alternative sources of flooding (e.g. urban drainage and/or groundwater) must be considered, and Sustainable Drainage techniques must be employed to ensure no worsening to existing flooding problems elsewhere within the area.
215. The SFRA provides specific recommendations with respect to the provision of sustainable flood risk mitigation opportunities that will address both the risk to life and the residual risk of flooding to development within particular ‘zones’ of the area. These recommendations should form the basis for the site-based FRA.
6.6.2 Raised Floor Levels & Basements (Freeboard)
216. The raising of floor levels above the 1% AEP (100 year) fluvial flood level, or the 0.5% (200 year) tidal flood level (whichever is greater), will ensure that the damage to property is minimised. Given the anticipated increase in flood levels due to climate change, the adopted floor level should be raised above the greater of the 1% AEP (100 year) fluvial or 0.5% (200 year) tidal predicted flood level assuming a 20% increase in flow over the next 50 years.
217. Wherever possible, floor levels should be situated a minimum of 300mm above the 1% AEP (100 year) plus climate change flood level, determined as an outcome of the site based FRA, or 600mm above the 1% AEP (100 year) fluvial, or 0.5% (200 year) tidal (whichever is greater), flood level if no climate change data is available. The height that the floor level is raised above flood level is referred to as the ‘freeboard’, and is determined as a measure of the residual risks.
218. The Environment Agency opposes the habitable use of basements within flood affected areas. Where basement uses are permitted however, it is necessary to ensure that the basement access points are situated 300mm above the greater of the 1% AEP (100 year) fluvial or 0.5% (200 year) tidal flood level plus climate change. The basement must be of a waterproof construction to avoid seepage during flooding conditions. Habitable uses of basements within flood affected areas should not be permitted.
6.6.3 Sustainable Drainage (SUDS)
219. SUDS is a term used to describe the various approaches that can be used to manage surface water drainage in a way that mimics the natural environment. The management of rainfall (surface water) is considered an essential element of reducing future flood risk to both the site and its surroundings. Indeed reducing the rate of discharge from urban sites to greenfield runoff rates (as described in Section 5.4) is one of the most effective ways of reducing and managing flood risk within the District.
220. SUDS may improve the sustainable management of water for a site by11: ¾ reducing peak flows to watercourses or sewers and potentially reducing the risk of flooding downstream; ¾ reducing volumes and the frequency of water flowing directly to watercourses or sewers from developed sites; ¾ improving water quality over conventional surface water sewers by removing pollutants from diffuse pollutant sources; ¾ reducing potable water demand through rainwater harvesting; ¾ improving amenity through the provision of public open space and wildlife habitat; ¾ replicating natural drainage patterns, including the recharge of groundwater so that base flows are maintained.
221. In catchment terms, any reduction in the amount of water that originates from any given site is likely to be small. But if applied across the catchment in a consistent way, the cumulative affect of a number sites could be significant.
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222. There are numerous different ways that SUDS can be incorporated into a development and the most commonly found components of a SUDS system are described in the following table12. The appropriate application of a SUDS scheme to a specific development is heavily dependent upon the topography and geology of the site (and its surrounds). Careful consideration of the site characteristics must be assured to ensure the future sustainability of the adopted drainage system.
Pervious surfaces Surfaces that allow inflow of rainwater into the underlying construction or soil.
Green roofs Vegetated roofs that reduce the volume and rate of runoff and remove pollution.
Linear drains consisting of trenches filled with a permeable material, often with a Filter drain perforated pipe in the base of the trench to assist drainage, to store and conduct water; they may also permit infiltration.
Vegetated areas of gently sloping ground designed to drain water evenly off Filter strips impermeable areas and to filter out silt and other particulates.
Shallow vegetated channels that conduct and retain water, and may also permit Swales infiltration; the vegetation filters particulate matter.
Basins, Ponds and Areas that may be utilised for surface runoff storage. Wetlands
Sub-surface structures to promote the infiltration of surface water to ground. They can Infiltration Devices be trenches, basins or soakaways.
Vegetated areas designed to collect and treat water before discharge via a piped Bioretention areas system or infiltration to the ground
A series of conduits and their accessories normally laid underground that convey surface water to a suitable location for treatment and/or disposal. (Although sustainable, Pipes and accessories these techniques should be considered where other SUDS techniques are not practicable).
223. For more guidance on SUDS, the following documents and websites are recommended as a starting point:
¾ Interim Code of Practice for Sustainable Drainage Systems, National SUDS Working Group, 2004 ¾ Planning Policy Statement 25, Annex F, Office of the Deputy Prime Minister, 2005 ¾ The SUDS manual (www.ciria.org.uk/suds/) ¾ Site handbook for the construction of SUDS (www.ciria.org.uk/suds/) ¾ Sustainable water management in schools (www.ciria.org.uk/suds/) ¾ Designing for exceedance in urban drainage: Good Practice (www.ciria.org.uk/suds/) ¾ Interim Code of Practice for SUDS (www.ciria.org.uk/suds/) ¾ Model agreements for sustainable drainage systems (www.ciria.org.uk/suds/) ¾ Sustainable drainage systems. Hydraulic, structural and water quality (www.ciria.org.uk/suds/) ¾ Sustainable Drainage Systems – design manual for England and Wales (www.ciria.org.uk/suds/) ¾ Sustainable Drainage Systems – design manual for Scotland and Ireland (www.ciria.org.uk/suds/) ¾ Sustainable Drainage Systems – best practice manual (www.ciria.org.uk/suds/) ¾ Source control using constructed pervious surfaces. Hydraulic. Structural and water quality performance issues (www.ciria.org.uk/suds/) ¾ Infiltration drainage – manual of good practice (www.ciria.org.uk/suds/)
12 Interim Code of Practice for Sustainable Drainage Systems National SUDS Working Group, 2004
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¾ Review of the design and management of constructed wetlands (www.ciria.org.uk/suds/) ¾ Control of pollution from highway drainage discharge (www.ciria.org.uk/suds/) ¾ Design of flood storage reservoirs (www.ciria.org.uk/suds/)
6.7 Local Community Actions to Reduce Flood Damage
224. Given the number of homes within the District that are at risk of flooding, it is essential to raise awareness, providing the community with the knowledge (and tools) that will enable them to help themselves should a flood event occur.
225. The following ‘community based measures’ are cost effective solutions that local communities may introduce to minimise the damage sustained to their own homes in the case of flooding.
6.7.1 Flood Proofing
226. The risk of flooding can never be fully removed. There will always be a residual risk of either the structural failure of a flood defence, and/or an event that exceeds the adopted design flood. For this reason, it is recommended that residents and business owners take action to minimise the impact that flooding may have upon their property. This may be achieved through a degree of ‘flood proofing’. The ‘flood proofing’ of a property may take a variety of forms:
For new homes and/or during redevelopment ¾ Raising of floor levels The raising of floor levels above the anticipated maximum flood level ensures that the interior of the property is not directly affected by flooding, avoiding damage to furnishings, wiring and interior walls. It is highlighted that plumbing may still be impacted as a result of mains sewer failure.
¾ Raising of electrical wiring The raising of electrical wiring and sockets within flood affected buildings reduces the risks to health and safety, and reduces the time required after a flood to rectify the damages sustained.
For existing homes ¾ Flood boards The placement of a temporary watertight seal across doors, windows and air bricks to avoid inundation of the building interior. This may be suitable for relatively short periods of flooding, however the porosity of brickwork may result in damage being sustained should water levels remain elevated for an extended period of time. This may lessen the effectiveness of flood proofing to existing properties affected by flooding from larger river systems such as the Lune
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6.8 Emergency Planning
227. The Council is designated as a Category 1 Responder under the Civil Contingencies Act 2004. As such, the Council has defined responsibilities to assess risk, and respond appropriately in case of an emergency, including (for example) a major flooding event. The Council’s primary responsibilities are13: a. from time to time assess the risk of an emergency occurring; b. from time to time assess the risk of an emergency making it necessary or expedient for the person or body to perform any of his or its functions; c. maintain plans for the purpose of ensuring, so far as is reasonably practicable, that if an emergency occurs the person or body is able to continue to perform his or its functions; d. maintain plans for the purpose of ensuring that if an emergency occurs or is likely to occur the person or body is able to perform his or its functions so far as necessary or desirable for the purpose of: i. preventing the emergency, ii. reducing, controlling or mitigating its effects, or iii. taking other action in connection with it
228. The SFRA provides a concise summary of the possible sources of flooding within the District, and may be used to inform the assessment of flood risk in response to the requirements of the Act. 229. The Environment Agency monitors river levels within a number of the main rivers affecting the District. Based upon weather predictions provided by The Met Office, the Agency makes an assessment of the anticipated maximum water level that is likely to be reached within the proceeding hours (and/or days). Where these predicted water levels are expected to result in the inundation of populated areas14, the Environment Agency will issue a series of flood warnings, or severe flood warnings, within defined flood warning areas, encouraging residents to take action to avoid damage to property in the first instance. Such flood warnings are also a prompt for the emergency services and other responder agencies to meet and agree the appropriate response to the situation. 230. As water levels rise and begin to pose a risk to life and/or livelihood, it is the responsibility of the police to coordinate the response of the emergency services. Any evacuation will be supported by the Council. It is essential that a robust plan is in place that clearly sets out (as a minimum): ¾ roles and responsibilities; ¾ paths of communication; ¾ evacuation routes; ¾ designated Rest Centres to house evacuated persons; ¾ contingency plans in case of loss of power and/or communication. 231. Coordination with the emergency services and the Environment Agency is imperative to ensure the safety of residents in time of flood. Areas within the District that are adjoining watercourses and/or the coast, and are at risk of river flooding (as indicated by the shaded PPS25 flood risk zones in the adjoining maps), are often susceptible to relatively long duration rainfall events, and considerable forewarning will generally be provided to encourage preparation in an effort to minimise property damage and risk to life.
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232. In contrast, areas suffering from localised flooding issues (and areas at risk of flooding from the smaller tributaries) will tend to be susceptible to ‘flash’ flooding, associated with storm cells that pass over the district. Storms of this nature result in high intensity, often relatively localised, rainfall. It is anticipated that events of this nature will occur more often as a result of possible climate change over the coming decades. Events of this nature are difficult to predict accurately, and the rapid runoff that follows will often result in flooding that cannot be forewarned. Whilst preparations can be made in response to flood warnings in known flood risk areas, the same response cannot be made for localised flash floods. 233. All urbanised areas are potentially at some degree risk of localised flooding due to heavy rainfall. The blockage of gullies and culverts as a result of litter and/or leaves is commonplace, and this will inevitably lead to localised problems that can only realistically be addressed by reactive maintenance.
234. The Council’s Flooding and Severe Weather Plan has recently been produced, and will be regularly reviewed in light of the findings and recommendations of the SFRA to ensure that safe access can be provided during a major flooding event.
6.9 Insurance
235. Many residents and business owners perceive insurance to be a final safeguard should damages be sustained as a result of a natural disaster such as flooding. Considerable media interest followed the widespread flooding of 2000 when it became clear that the insurance industry were rigorously reviewing their approach to providing insurance protection to homes and businesses situated within flood affected areas. Not surprisingly, the recent widespread flooding of July 2007 has further exacerbated the discussion surrounding the future of insurance for householders and business owners situated within flood affected areas.
236. The following quotations are an extract from the Association of British Insurers (ABI) website, dated August 2007:
“The UK is unique in offering flood cover as a standard feature of household and most business policies. Unlike much of Europe and worldwide, cover is widely available to the UK’s 23.5 million householders.
In the long term, this situation could worsen, unless we take action to reduce flood risk to people and property. Climate change will increase winter rainfall, the frequency of heavy rainfall, and sea levels and storm surge heights. With no change in Government policies or spending, climate change could increase the number of properties at risk of flooding to 3.5 million. Furthermore, continued pressure on land could mean even more new developments being situated in floodplains.
In 2003 ABI members agreed to extend their commitment to provide flood insurance to the vast majority of UK customers. The result of discussions between Government and insurers was a Statement of Principles, which aims to provide reassurance to the overwhelming majority of insurance customers living in the floodplain about the continued availability of insurance in future.
Individual property owners can do much to increase the resistance and resilience of their properties to flood damage - further information is available. ABI has issued a factsheet for property owners on a range of measures that could be taken by a homeowner to improve the resilience of their property to flood damage.”
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237. In summary, for the time being, residents and business owners can be assured that insurance will be available to assist in recovery following a flood event. It would appear fair to say however that the future availability of flood insurance within the UK will be heavily dependant upon commitment from the government to reduce the risk of flooding over time, particularly given the anticipated impacts of climate change. Investment is required in flood defence and improving the capacity of sewage and drainage infrastructure, however it is also essential to ensure that spatial planning decisions do not place property within areas at risk of flooding.
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7 Conclusion & Recommendations
238. A relatively small proportion of the District of Lancaster is at risk of flooding. The risk of flooding posed to properties within the District arises from a number of sources including river and tidal flooding, localised runoff, sewer and groundwater flooding.
239. A collation of potential sources of flood risk has been carried out in accordance with PPS25, developed in close consultation with both the Council and the Environment Agency. The District has been broken down into zones of ‘high’, ‘medium’ and ‘low’ probability of flooding in accordance with PPS25, providing the basis for the application of the PPS25 Sequential Test.
240. Substantial investment in flood defence has been delivered within the District, providing a degree of protection to existing property in the form of Morecambe Coastal Works Scheme, as well as the River Lune flood defences at Luneside (currently under construction). A residual risk of flooding remains however, associated both with an event that may exceed the design capacity of the defences, and/or a structural failure.
241. A planning solution to flood risk management should be sought wherever possible, steering vulnerable development away from areas affected by flooding in accordance with the PPS25 Sequential Test. Specific planning recommendations have been provided for all urban centres within the District.
242. Where other planning considerations must guide the allocation of sites and the Sequential Test cannot be satisfied, specific recommendations have been provided to assist the Council and the developer to meet the Exception Test. These should be applied as development control conditions for all future development.
243. Council policy is essential to ensure that the recommended development control conditions can be imposed consistently at the planning application stage. This is essential to achieve future sustainability within the District with respect to flood risk management. Current flood risk policy is considered generally robust and in line with PPS25 ‘intent’. It is recommended however that supporting Supplementary Planning Document is developed in light of the suggested development control conditions presented by Lancaster SFRA.
244. Emergency planning is imperative to minimise the risk to life posed by flooding within the District. It is recommended that the Council review their adopted flood risk response plan in light of the findings and recommendations of the SFRA. A Living Document
245. The SFRA has been developed building heavily upon existing knowledge with respect to flood risk within the district. A rolling programme of detailed flood risk mapping and strategic flood risk management investigations within the North West region is underway. This, in addition to observed flooding that may occur throughout a year, will improve the current knowledge of flood risk within the district and may marginally alter predicted flood extents within Lancaster. Furthermore, Communities and Local Government (CLG) are working to provide further detailed advice with respect to the application of PPS25, and future amendments to the PPS25 Practice Guide are anticipated. Given that this is the case, a periodic review of the Lancaster District SFRA is imperative.
246. It is recommended that the Lancaster District SFRA is reviewed once every 12 months, commencing in July 2008. The following key questions should be addressed as part of the SFRA review process:
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Question 1 Has any flooding been observed within the District since the previous review? If so, the following information should be captured as an addendum to the SFRA:
¾ What was the mapped extent of the flooding? ¾ On what date did the flooding occur? ¾ What was the perceived cause of the flooding? ¾ If possible, what was the indicative statistical probability of the observed flooding event? (i.e. how often, on average, would an event of that magnitude be observed within the District?) ¾ If the flooding was caused by overtopping of the riverbanks, are the observed flood extents situated outside of the current Zone 3a? If it is estimated that the frequency of flooding does not exceed, on average, once in every 100 years then the flooded areas (from the river) should be incorporated into Zone 3a to inform future planning decision making.
Question 2 Have any amendments to PPS25 or the Practice Companion Guide been released since the previous review? If so, the following key questions should be tested:
¾ Does the revision to the policy guidance alter the definition of the PPS25 Flood Zones presented within the SFRA? (refer Section 5.2) ¾ Does the revision to the policy guidance alter the decision making process required to satisfy the Sequential Test? (refer Section 6.4.1) ¾ Does the revision to the policy guidance alter the application of the Exception Test? (refer Section 6.4.1) ¾ Does the revision to the policy guidance alter the categorisation of land use vulnerability, presented within Table D2 of PPS25 (December 2006)? If the answer to any of these core questions is ‘yes’ then a review of the SFRA recommendations in light of the identified policy change should be carried out.
Question 3 Has the Environment Agency issued any amendments to their flood risk mapping and/or standing guidance since the previous policy review? If so:
¾ Has any further detailed flood risk mapping been completed within the District, resulting in a change to the 20 year, 100 year or 1000 year flood outline? If yes, then the Zone 3b and Zone 3a flood outlines should be updated accordingly. ¾ Has the assessment of the impacts that climate change may have upon rainfall and/or river flows over time altered? (refer Section 5.6) If yes, then a review of the impacts that climate change may have upon the District is required. ¾ Do the development control recommendations provided in Section 6.4 of the SFRA in any way contradict emerging EA advice with respect to (for example) the provision of emergency access, the setting of floor levels and the integration of sustainable drainage techniques? If yes, then a discussion with the EA is required to ensure an agreed suite of development control requirements are in place.
Question 4 Have any updates been made to the studies that underpin strategic flood risk management within the District, including the Catchment Flood Management Plan, the Shoreline Management Plan, and/or the River Basin Management Plan? If so:
¾ Have the policies recommended within the strategy altered, changing the way in which flood risk management may be delivered within the District in future years? For example, has a decision been taken to cease the maintenance of flood defences within a particular reach of the coastline and/or River Lune, resulting in an increase in flooding in future years? If so, then the findings and recommendations of the SFRA should be reviewed and revised accordingly to ensure that future development within the affected areas will be sustainable in the long term.
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It is highlighted that the Environment Agency review the Flood Zone Map on a quarterly basis. If this has been revised within the District, the updated Flood Zones will be automatically forwarded to the Council for their reference. It is recommended that only those areas that have been amended by the Environment Agency since the previous SFRA review are reflected in Zone 3 and Zone 2 of the SFRA flood maps. This ensures that the more rigorous analyses carried out as part of the SFRA process are not inadvertently lost by a simple global replacement of the SFRA flood maps with the Flood Zone Maps.
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Bibliography
September 2007 (Final) 1
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Environment Agency Coastal Flood Risk Mapping - Summary Report; July 2001
Lune Catchment Absraction Management Strategy Technical Document; February 2004
Managing Flood Risk: River Lune Catchment Flood Management Plan, Inception Reportl; September 2006
Lancaster City Council, Planning Services Morecambe Coastal Works Scheme History; February 1991
Halcrow Group Ltd Lune Estuary Habitat Management Study Modelling Report, Stage 2b: Processes/Habitat Assessment; January 2004
National Property Dataset, National Property Dataset Updated 2005; December 2005
Lancaster City Council Core Strategy; July 2006
Lancaster District Local Plan 1996-2000; April 2004
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Appendix A SFRA User Guide
September 2007 (Final) 1
Council Planners must work through The Sequential Test (refer SFRA Section 6.4.1) before considering the nature of the development as outlined below Development must be restricted to ‘water No Is proposed allocation situated compatible uses’ (PPS25 Table D2) Is proposed allocation an within Zone 3b Functional existing developed site? Floodplain? Yes Development must be restricted in Yes accordance with Section 6.4.3 of the No SFRA
Is proposed allocation situated No Is proposed allocation situated Is proposed land use categorised as within Zone 3a High within Zone 2 Medium Yes ‘highly vulnerable’ (PPS25 Table Probability? Probability? D2)? Yes No
Is proposed land use categorised as No PPS25 related constraints ‘less’ vulnerable (PPS25 Table D2)? Yes upon development No Yes
No
It is necessary for the development to pass The Exception Test
It must be demonstrated that the development provides wider sustainability benefits to the community that outweigh flood risk.
The development should be on developable previously developed land. If it is not on previously developed land, then there must be no reasonable alternative sites on developable previously developed land.
Planning conditions must be in place to ensure that the development will be safe, without increasing the flood risk elsewhere and, where possible, will reduce flood risk overall. FIGURE B1 Lancaster District Council Strategic Flood Risk Assessment User Guide (Planning) Development must be restricted to ‘water Developers must work through The No Sequential Test Is development situated within compatible uses’ (PPS25 Table D2) (refer SFRA Section 6.4.1) before Zone 3b Functional considering the nature of the development Floodplain? Development must be restricted in as outlined below Yes accordance with Section 6.4.3 of the No SFRA
Is development situated within Is development situated within Is proposed land use categorised as Zone 3a High Probability? Zone 2 Medium Probability? ‘highly vulnerable’ (PPS25 Table No Yes D2)? Yes No No No Is proposed land use categorised as PPS25 is satisfied. A drainage impact assessment is ‘less’ vulnerable (PPS25 Table D2)? required to ensure development does not exacerbate localised flooding problems elsewhere. Within Zone 2 Yes Medium Probability it will be necessary to demonstrate that the residual risk of flooding to the property is Yes PPS25 is satisfied. A detailed FRA must effectively managed through, for example, the raising demonstrate the risk to property and life within of floor levels and the provision of a planned the site (due to flooding) can be mitigated over evacuation route and/or safe haven. the lifetime of the development, resulting in no Refer SFRA Section 6.3. worsening to adjoining properties. Refer SFRA Section 6.3.
It is necessary for the development to pass The Exception Test
The developer must demonstrate that the development provides wider sustainability benefits to the community that outweigh flood risk.
If not on previously developed land, the developer must demonstrate that there are no reasonable alternative sites on developable previously developed land.
A detailed FRA must demonstrate that the risk to property and life within the site (due to flooding) can be mitigated over the lifetime of the development, resulting in no worsening to adjoining properties. Where FIGURE B2 possible, a reduction in flood risk should be sought. Lancaster District Council Refer SFRA Section 6.3. Strategic Flood Risk Assessment User Guide (Development Control) Lancaster City Council STRATEGIC FLOOD RISK ASSESSMENT (SFRA)
Appendix B PPS25 Constraints upon Emerging Sites
September 2007 (Final) 1
Lancaster City Council STRATEGIC FLOOD RISK ASSESSMENT (SFRA) PPS25 Constraints upon Emerging Areas of Change
Overview
In accordance with PPS25, it is necessary for a local authority to adopt a sequential approach when allocating sites for future development. This is outlined in Section 6.4.1 of the SFRA, however in simple terms it must be demonstrated that sites for future development have been sought within the lowest flood risk zone (i.e. Zone 1 Low Probability). Only if it can be shown that suitable sites are not available within this zone can alternative sites be considered within the areas that are at greater risk of possible flooding.
The SFRA does not endeavour to address this aspect of the Sequential Test. It can however review emerging allocations, and in light of the delineated PPS25 flood zones, provide clear recommendations for permissible land uses (as defined by PPS25).
The Adopted Approach
A review of emerging housing and employment allocations has been undertaken as part of the SFRA process. Emerging areas of change as identified by the Council were overlaid onto the adopted PPS25 flood zones. The attached table summarises:
¾ the locality of each nominated site; ¾ the flood zone within which that site falls; and ¾ the restrictions that flood risk places upon the future development of the site.
It is highlighted that the SFRA has been developed in parallel to the ‘live’ planning process. Therefore, at the time of writing, the Council were able to provide emerging decisions taken with respect to specific sites that will influence the status of the allocation (e.g. exclusion and/or land use change on flood risk grounds).
Interpretation of Housing & Employment Sites Review (attached table)
The attached table has adopted a ‘traffic light’ system to mirror the decision matrix provided within PPS25 (Appendix D). The table should be interpreted in accordance with the following legend.
It is highlighted that, in some instances, sites are only partially affected by flooding. In these instances, the ‘traffic lights’ within the attached matrix reflect the most significant risk of flooding within the site. At these locations, future development may be permitted to proceed, however this should be restricted to the lowest risk areas of the site if at all possible.
September 2007 (Final)
Source: PPS25 Appendix D, Table D2 (December 2006)
Lancaster SFRA APPENDIX B September 2007 Land Use Vulnerability Permissible Land Use (PPS25 Sequential Test) Address Town Reference Map PPS25 Zone Comment Essential Highly Vulnerable More Vulnerable Less Vulnerable Water Compatible Infrastructure
Lancaster Moor North, Wyresdale Road Lancaster 1 B10 1 Housing and Mixed Use Opportunity site
Abbatoir, Wyresdale Road, Lancaster 2 B10 1 Residential developer interest
Lancaster Leisure Park Lancaster 3 B10 3a Residential developer interest. Partially affected.
Employment site. Currently subject of residential Luneside West Lancaster 4 B6 3a appeal. Defended site.
Residential site. Defended site, partially affected Luneside East Lancaster 5 B6 3a by flood risk. Rest of site in Zone 2 and 1
Bailrigg Business Park Lancaster 6 B11 1 Employment site.
Bailrigg, Lancaster Lancaster 7 B11 1 Potential residential developer interest.
Potential residential developer interest. Partially Whinney Car Farm, Lancaster Lancaster 8 B11 3a affected
Potential residential developer interest. Partially Lawson's Bridge Lancaster 9 B11 3a affected
Royal Albert West Lancaster 9a B11 1 Potential residential developer interest.
Lancaster University Lancaster 10 B12 1
Caton Road and Lancaster Business Parks Lancaster 11 B7 3b Employment uses.
Centros Miller proposal Lancaster 12 B10 1 Retail, residential and office proposals.
Nightingale Hall Farm Lancaster 13 B10 1
Salt Ayre Lancaster 14 B6 1 Landfill site.
Rsidential developer interest. Partially affected. Powder House Lane Lancaster 15 B7 3a Rest of site in Zone 1.
Hammerton Hall Bridge Lancaster 16 B7 1 Potential residential developer interest.
Powder House Land Rugby and Cricket Lancaster 17 B7 1 Potential residential developer interest. Grounds
Partially affected at junction with M6. The majority M6 Link Road Lancaster 18 B7/B8 3a of site is within Zone 1
Approximately half of the site affected. Rest of site Halton Training Camp Lancaster 19a B7 2 is in Zone 1
Mellishaw Lane Lancaster 20 B6 3a Employment site.
White Lund Lancaster 21 B6 3a Employment site.
Regent Road and Westgate Morecambe 22 B5 3a Housing site.
Bubbles development area Morecambe 23 B5 3a Residential and commercial proposals.
Frontierland Morecambe 24 B5 1 Retail and residential proposals
Mossgate Heysham 25 B14 1 Housing under construction
Heysham Port and Port of Heysham Heysham 26 B14 3a Partially affected. Rest of site in Zone 1 Industrial Estate
Heysham Power Station Heysham 27 B14 3a Partially affected. Rest of site in Zone 1
Major Industrial Estate, Middleton Heysham 28 B14 1
Lancaster West Business Park, Middleton Heysham 29 B15 1
Heysham Industrial Estate, Middleton Heysham 30 B15 1
Middleton Wood Heysham 31 B15 1
Former Pontins Holiday Camp Heysham 32 B15 3a Partially affected. Rest of site in Zone 1
Carnforth Business Park Carnforth 33 B2 3a Partially affected. Rest of site in Zone 1
Warton Road employment site Carnforth 34 B2 1
Carnforth levels Carnforth 35 B2 2 Partially affected. Rest of site in Zone 1
Millhead Carnforth 36 B2 2 Employment site.
Scotland Road Carnforth 37 B2 2 Partially affected only. Rest of site in Zone 1
Lundsfield Quarry Carnforth 38 B2 1
Carnforth Levels and Scotland Road Carnforth 39 B2 3b Greenfield
Lune Mills Halton 40 B8 2 Residential and employment site.
Coastal Road Bolton-Le-Sands 41 B4 1 Residential site.
Lancaster District SFRA APPENDIX B October 2007 Review of PPS25 Constraints
Lancaster District SFRA
List of Figures
Figure A - Lancaster District Figure B - Map Layout Index Figure C - Historical Flooding Figure D - Localised Flooding Issues Figure E - Proposed and Existing Critical Infrastructure Figure F - Evacuation Routes
Figure B1 - Character Area B1 - Silverdale Figure B2 - Character Area B2 - Carnforth Figure B3 - Character Area B3 - Bolton-le-Sands Figure B4 - Character Area B4 – Slyne-with-Hest Figure B5 - Character Area B5 – Morecambe Central and West End Figure B6 - Character Area B6 – White Lund and Luneside Figure B7 - Character Area B7 – North East Lancaster Figure B8 - Character Area B8 - Halton Figure B9 - Character Area B9 – Caton and Brookhouse Figure B10 - Character Area B11 – Scotforth Figure B12 - Character Area B12 – East Lancaster Figure B13 - Character Area B13 – Hornby Figure B14 - Character Area B14 – Heysham Figure B15 - Character Area B15 – Middleton
September 2007