Chesterfield, and North East SFRA Strategic Flood Risk Assessment

Chesterfield Borough Council, Council and NE Derbyshire District Council March 2009

Table of Contents

Executive Summary ...... 8

1 ...... Introduction ...... 16 1.1 The need for a SFRA ...... 16 1.2 SFRA Objectives ...... 17 1.3 Planning Policy ...... 17 1.4 Methodology ...... 24 1.5 The Study Area ...... 24 2 ...... Flood Risk ...... 28 2.1 Responsibilities ...... 28 2.2 Planning Policy Statement 25 ...... 31 2.3 Flood Mapping ...... 35 3 ...... Data Collection ...... 40 3.1 Flood Zone maps ...... 40 3.2 Topography ...... 40 3.3 Hydraulic Models ...... 40 3.4 Flood Alleviation Schemes ...... 41 3.5 Historic flooding ...... 41 3.6 Defences ...... 41 3.7 Flood warning ...... 42 3.8 Other related plans and strategies...... 43 3.9 Data collection for other sources of flood risk ...... 44 3.10 Data deficiencies...... 45 4 ...... Causes of flooding ...... 52 4.1 Overflowing of watercourses (including Breach) ...... 52 4.2 Breaching of Embankments ...... 53 4.3 Mechanical, Structural or Operational Failure ...... 54 4.4 Flooding from reservoirs, canals and Other Artificial Sources ...... 55 4.5 Groundwater Flooding ...... 55 4.6 Land drainage, sewer and ordinary watercourse flooding ...... 55 4.7 Catchment characteristics ...... 57 4.8 Flood Protection of the catchment ...... 58 5 ...... Flooding in Chesterfield, Bolsover and ...... 62 5.1 Main River Flooding in Chesterfield ...... 62 5.2 Analysis of problem areas in Chesterfield ...... 63 5.3 Main River Flooding in Bolsover ...... 65 5.4 Analysis of problem areas in Bolsover ...... 66 5.5 Main River Flooding in North East Derbyshire ...... 67 5.6 Analysis of problem areas in North East Derbyshire ...... 67 5.7 Sewer Flooding ...... 68 5.8 Groundwater flooding and Surface Water Run-off ...... 74 5.9 Other sources of flooding ...... 76 6 ...... Strategic Assessment of Flood Risk ...... 80 6.1 Plans and Mapping ...... 80 6.2 Flood risk profile ...... 83 6.3 Climate change ...... 86 6.4 Land use changes for Chesterfield ...... 86 6.5 Risk from assets ...... 87 6.6 Flood risk from reservoirs ...... 88 6.7 Mitigation for Flood Zones ...... 90 6.8 Existing Defences below the Required Standard of Protection ...... 92

7 ...... Development in Chesterfield, Bolsover and North East Derbyshire ...... 96 7.1 Summary of Regional Flood Risk Assessment ...... 96 7.2 Chesterfield, Bolsover and NE Derbyshire Area ...... 98 8 ...... Assessment of Flood Risk in Study Areas ...... 104 8.1 The Sequential Test ...... 104 8.2 Application of the Sequential Test ...... 105 8.3 The Sequential Approach ...... 105 8.4 Flood risk matrix explanation ...... 107 8.5 General summary ...... 108 8.6 General requirements for planning applications ...... 109 8.7 How to use the SFRA to apply the Sequential Test ...... 115 9 ...... Flood Risk Policies ...... 120 9.1 Current Planning Policy ...... 120 9.2 LDF Draft flood risk policies ...... 122 9.3 SuDS ...... 125 9.4 Culverting of Open Watercourses ...... 125 9.5 Climate Change ...... 126 9.6 Afforestation ...... 126 9.7 Increased Impermeability ...... 126 9.8 Runoff Rates ...... 127 10 ...... Conclusions and Recommendations ...... 130 10.1 Conclusions ...... 130 10.2 Recommendations ...... 131 Glossary ...... 134

Appendix A: Historical Flooding Matrix...... 142 Appendix B: List of development sites ...... 144 Appendix C: Data Register ...... 146 Appendix D: Maps ...... 148 Appendix E: Use of SuDS and sustainable development ...... 154

Table 1: Key development planning tools in PPS25 (taken from PPS25) ...... 17 Table 2: PPS25 Flood Zones (taken from PPS25) ...... 31 Table 3: Flood Risk Vulnerability Classification from PPS25 (taken from PPS25) ...... 33 Table 4: Flood Map Types ...... 35 Table 5: Flood Warning Areas in Chesterfield, Bolsover and NE Derbyshire ...... 43 Table 6: CBC Sewerage flooding ...... 69 Table 7: BDC Sewerage flooding ...... 71 Table 8: NEDDC Sewer flooding ...... 73 Table 9: Danger to people from breaching relative to distance from defence ...... 84 Table 10: Danger to people from overtopping relative to distance from defence ...... 84 Table 11: Danger to people for different combinations of depth and velocity ...... 85 Table 12: Recommended increases in peak rainfall intensities ...... 86 Table 13: Percentage of properties that are in Flood Zone 3 ...... 96 Table 14: LPA areas benefiting from defences...... 97 Table 15: LPA areas at risk from secondary sources of flooding...... 97 Table 16: LPA Areas Residual Risk...... 97 Table 17: Flood Risk Profile ...... 98 Table 18: General responses for all proposed developments ...... 109 Table 19: Appropriate uses of land in Flood Zones ...... 124

Figure 1: SFRA Study Area Showing Main Rivers ...... 18 Figure 2: Development planning process for flood risk (taken from PPS25 Practice Guide) ..... 20 Figure 3: Process and links to the LDF from PPS25 ...... 22 Figure 4: Individual planning applications – guidance for developers from PPS25 ...... 23 Figure 5: Flood Risk Vulnerability and Flood Zone ‘Compatibility (taken from PPS251)...... 35 Figure 6: Groundwater Vulnerability Plan ...... 48 Figure 7: Application of the Sequential Test (taken from PPS25) ...... 106 Figure 8: Flood Risk Assessment Matrix ...... 112

Figure 9: Sequential Test Requirements ...... 117

List of Maps(Contained in Appendix D).……………………………………………………..….149 List of Maps - North East Derbyshire……………………………………………………………..…149 Development Sites - North East Derbyshire Area 01 Development Sites - North East Derbyshire Area 02 Development Sites - North East Derbyshire Area 03 Development Sites - North East Derbyshire Area 04 Development Sites - North East Derbyshire Area 05 Development Sites - North East Derbyshire Area 06 Development Sites - North East Derbyshire Area 07 Development Sites - North East Derbyshire Area 08 Development Sites - North East Derbyshire Area 09 Development Sites - North East Derbyshire Area 10 Development Sites - North East Derbyshire Overview Assets - North East Derbyshire Area 01 Assets - North East Derbyshire Overview Flood Zones - North East Derbyshire Area 01 Flood Zones - North East Derbyshire Area 02 Flood Zones - North East Derbyshire Area 03 Flood Zones - North East Derbyshire Overview Historic Flooding, Flood Storage and Defences - North East Derbyshire Area 01 Historic Flooding, Flood Storage and Defences - North East Derbyshire Area 02 Historic Flooding, Flood Storage and Defences - North East Derbyshire Area 03 Historic Flooding, Flood Storage and Defences - North East Derbyshire Area 04 Historic Flooding, Flood Storage and Defences - North East Derbyshire Area 05 Historic Flooding, Flood Storage and Defences - North East Derbyshire Area 06 Historic Flooding, Flood Storage and Defences - North East Derbyshire Area 07 Historic Flooding, Flood Storage and Defences - North East Derbyshire Area 08 Historic Flooding, Flood Storage and Defences - North East Derbyshire Overview

Abbreviations / Acronyms

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Abbreviations / Acronyms

AMP Asset Management Plan

AOD Above Ordnance Datum

BDC Bolsover District Council

CBC Chesterfield Borough Council

CFMP Catchment flood management plan

CIRIA Construction Industry Research Information Association

CLG (Department of) Communities and Local Government

Defra Department for Environment, Food and Rural Affairs

DPD Development Plan Documents

EA Environment Agency

FRA Site Specific Flood Risk Assessment

FZ Flood Zone

GIS Geographical Information System

IDB Internal Drainage Board

LDD Local development document

LiDAR Light Detection and Ranging

LDF Local Development Framework

LPA Local Planning Authority

NEDDC North East Derbyshire District Council

NFCDD National Flood and Coastal Defence Database

ODPM Office of the Deputy Prime Minister (now CLG)

Ofwat Water Services Regulation Authority

PPG Planning Policy Guidance Note

PPS Planning Policy Statement

PPS 25 Planning Policy Statement 25

RBMP River Basin Management Plan

RFRA Regional Flood Risk Appraisal (RFRA)

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Riparian Persons who own land on the banks of a watercourse or other body of water RPB Regional Planning Body

RSS Regional Spatial Strategy

S106 Section 106 of the Town and Country Planning Act 1990: (Agreement) allows a LPA to enter into a legally-binding agreement or planning obligation, with a land developer over a related issue.

SA Sustainability Appraisal

SEA Strategic Environmental Assessment

SFRA Strategic Flood Risk Assessment

SHLAA Strategic Housing Land Availability Assessment

SPD Supplementary Planning Document

SuDS Sustainable Drainage Systems

SOP Standard of Protection

Executive Summary

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Executive Summary

ES1. Introduction

ES1.1 This report is a Strategic Flood Risk Assessment (SFRA) for Chesterfield Borough Council, North East Derbyshire District Council and Bolsover District Council. This SFRA has been prepared in accordance with current best practice, Planning Policy Statement 25 Development and Flood Risk (PPS25) and the accompanying ‘living draft’ Practice Guide (June 2008).

ES1.2 The SFRA is a planning tool that enables the council to select and develop sustainable site allocations away from vulnerable flood risk areas. The assessment focuses on the existing site allocations within the districts but also sets out the procedure to be followed when assessing additional sites for development in the future. The SFRA will assist each council to make the spatial planning decisions required to inform the Local Development Framework (LDF).

ES1.3 The SFRA identifies existing flood risk management measures, including infrastructure and the coverage of flood warning systems. Guidance on the preparation of FRAs for future development sites and the likely applicability of different sustainable drainage systems (SuDS) for managing surface water run-off is also included.

ES2. Flood Risk in the study area

ES2.1 In order of numbers of residents, the main population centres in the Study Area are Chesterfield, Bolsover, , , South Normanton, , Creswell, Renishaw, , Staveley, and Eckington, although there are also numerous other villages.

ES2.2 In Chesterfield, Bolsover, and North East Derbyshire there are many different types of flood risk present with the exception of tidal flooding. These include rivers (fluvial), groundwater (notably springs from aquifers), land drainage (low lying areas and runoff from steeply sloped areas), overland flow (pluvial), sewerage, other artificial sources e.g. reservoirs and canals and failure from assets (structures that provide a flood defence function).

ES2.3 Rivers are the main source of flooding in the Chesterfield Borough Council, Bolsover District Council and North East Derbyshire District Council SFRA area. The reason for this flood risk to people and property is a combination of insufficient channel capacity and the fact that the affected properties are generally on low lying land in the rivers’ natural floodplain.

ES2.4 The recent flooding within the study area (June 2007) is a stark reminder of the potential impact that floodwaters can have upon homes and businesses. It is important to remember that the risk of flooding is posed not only by rivers, but also by surface water runoff and the surcharging of sewers during particularly heavy and/or prolonged rainfall. Unless it is carefully designed, future development can make problems of this kind worse, by blocking flow paths and increasing the volume and speed of runoff from the site. With changing climate patterns, it is predicted that storms of this nature will become increasingly common, potentially increasing the risk posed to properties which are close to even quite small watercourses.

ES2.5 A regional flood risk assessment (RFRA) for the East was carried out by Faber Maunsell in July 2006 which assessed potential future flood risk from housing provision and development pressure. Chapter 7 discusses in detail the output from the RFRA in relation to flooding in the study area.

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ES2.6 Based on the Regional Flood Risk Assessment (2006) the overall flood risks to each LPA are:

• Chesterfield is classed as medium

• Bolsover is classed as low

• North East Derbyshire is classed as medium to low

ES3. Main risks from Rivers

Chesterfield

ES3.1 The River Rother has been identified as the watercourse that poses the greatest flood risk in Chesterfield. St Augustines in Chesterfield is a location in which failure from assets should be considered.

ES3.2 The areas in Chesterfield where assets are at potential risk of breach are the Road (St Augustines) area of Chesterfield (River Rother), the Rother-Hipper confluence up stream of Station Bridge (Rivers Rother and Hipper) and the Holland Road () area of Chesterfield (River Rother).

Bolsover

ES3.3 The River has been identified as the watercourse that poses the greatest flood risk in Bolsover. The only known assets within the Bolsover area are along the rural reaches of the and Normanton Brook. The consequence of increased flooding due to these assets is low.

ES3.4 The area in Bolsover where there is a potential risk of breach is at adjacent to the BDC boundary which is protected by flood embankments to a 1 in 100 year standard of protection along the right bank of the .

North East Derbyshire

ES3.5 The River Rother has been identified as the watercourse that poses the greatest flood risk in North East Derbyshire. Renishaw and Eckington are areas in NEDDC that have been identified as at risk of flooding from the River Rother.

ES3.6 The known assets within the NEDDC are along the and the River Rother. Parts of the assets along River Drone are near residential developments, in Dronfield. These assets should be regularly maintained and, if needed, upgraded in order to prevent localized flooding.

ES3.7 The area where assets are at a potential risk of breach is Slitting Mill Farm (River Rother) up stream of Eckington, which is at the boundary of NEDDC and CBC. There do not appear to be any major flood defences in NE Derbyshire where breach could significantly affect existing or future development sites.

ES4. How the SFRA has been developed

ES4.1 A thorough review of existing information was used to identify the level of flood risk at present within the study area from river and other sources. The SFRA identified that the significant source of flood risk within the area was from rivers.

ES4.2 The information on locations of flood risk has been put into a database, with each entry having a reference. These locations have been digitally mapped using a Geographical Information System so that it can be seen if a potential development site could be at risk from one of the potential sources of flood risk. Information such as historic flood outlines and defended areas has also been collected and mapped.

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ES4.3 No climate change modeling or flood extent mapping was available for the catchment area as a whole. However, professional judgement has been used to asses the likely impact of climate change.

ES4.4 The study area was delineated into four zones of flood risk in line with PPS25:

Zone 1: Low Probability. This zone comprises land assessed as having a less than 1 in 1000 annual probability of flooding in any year (<0.1%).

Zone 2: Medium Probability . This zone comprises land assessed as having between a 1 in 100 and 1 in 1000 annual probability of flooding (1% - 0.1%) in any year.

Zone 3a: High Probability. This zone comprises land assessed as having a 1 in 100 or greater annual probability of flooding (>1%) in any year. 

Zone 3b: The Functional Floodplain . This zone comprises land where water has to flow or be stored in times of flood. Equivalent to the 1 in 20 annual probability of flooding in any year (5%).

ES4.5 Within the study area there is a considerable variation in the depth, duration and frequency (and hence the consequence) of flooding to properties situated within Zone 3a. As a result, a further sub-delineation of flood risk has been carried out to assist the LPAs to guide future development to areas of lowest risk within Zone 3a, when it is not possible to find reasonable alternatives in a lower risk zone.

ES4.6 Existing developed areas (or areas with existing planning permission or an allocation that has been protected through the ‘Saved Policies’ review of the LPAs Local Plans) that are subject to flooding up to (and including) the 1 in 20 year (5%) annual probability have been highlighted as Zone 3a(ii) High Probability.

ES4.7 Areas situated within the 1% (100 year) flood envelope, but outside of the 5% (20 year) flood envelope, have been delineated as Zone 3a(i) High Probability.

ES4.8 The SFRA has been completed in close communication with the Environment Agency (EA). Officers of the EA attended progress meetings where technical issues have been discussed. The EA has also been available throughout the study for guidance to ensure the SFRA is completed in line with their objectives for flood risk management and planning. The SFRA needs to be updated regularly to reflect changes in national and local conditions and policies as these arise.

ES5. Application of the SFRA

ES5.1 PPS25 states that it is the responsibility of developers to consider carefully the flood risk issues at a site as early as possible. The Environment Agency on-line Flood Maps and the SFRA should provide some indication of whether a site is at risk of flooding. However developers should make independent checks prior to purchasing sites/developing sites.

ES5.2 The SFRA has gathered flood risk information in order to complete an initial Sequential Test for future development sites being considered by the LPAs, as described in par 16 of PPS25.

ES5.3 The sequential test requires that land for future development must first be sought within Zone 1 Low Probability. Only if it can be demonstrated that, for sound planning reasons, there are no suitable sites within this area, can sites elsewhere within the District be considered. Sites must then be sought within Zone 2 Medium Probability. Once again, only if it can be conclusively shown that there are sound planning reasons

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that outweigh the risk of flooding, can sites be considered for allocations in Zone 3 High Probability.

ES5.4 Where the Sequential Test has been applied, and the Local Authority considers that there are sound reasons to allocate a site within Zone 2 or Zone 3 on planning grounds, then PPS25 requires the LPA 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. This is through the application of the Exception Test and site specific Flood Risk Assessments.

ES5.5 To meet the Exception Test the developer should demonstrate the wider sustainability benefits that outweigh the flood risk implications of developing the site.

ES5.6 This SFRA provides enough information to allow the Sequential Test to be completed for any other sites that are to be brought forward for consideration in the future. The sequential approach should be carried out for sites located in areas at risk of flooding. The developers should make the most appropriate use of land to minimise flood risk, distributing land uses so that the most vulnerable development is located in the parts at lower risk.

ES5.7 A flood risk matrix has been produced to identify the highest risk potential future development allocations and summarise recommendations. This can be found in the Addendum of the SFRA. For sites affected by multiple Flood Zones, the LPAs should direct the most vulnerable types of development towards the least vulnerable parts of the sites (taking into account flood hazard and the different flood extents).

ES5.8 It is important to remember however that development in low risk areas, if not carefully managed, may exacerbate existing flooding and/or drainage problems downstream or at a lower level than the development. It is necessary therefore to ensure that developers carry out a Flood Risk Assessment which concentrates on surface water. This should demonstrate that the proposed drainage system design will mitigate any possible increase in runoff that may occur from the site as a result of the proposed development.

ES6. Planning Policy Recommendations

ES6.1 In consultation with the Environment Agency and the LPAs, the SFRA has developed a suite of specific spatial planning recommendations that should underpin all future development.

ES6.2 POLICY RECOMMENDATION 1 - The Need for a Flood Risk Assessment

The Council may require the submission of an appropriate site specific Flood Risk Assessment from the developer in connection with any application for planning permission.

ES6.3 POLICY RECOMMENDATION 2 - Development in areas deemed to be at Low Probability of flooding, (Flood Zone 1)

The LPA’s SFRA has classified all land within one or other of the four Flood Zones described in the SFRA. This classification does not remove the need for site specific FRAs.

ES6.4 POLICY RECOMMENDATION 3 - Development in areas deemed to be at Medium to High Probability of flooding (Flood Zones 2 and 3a)

Developments within the natural floodplain of a river or stream are inherently at risk of flooding and can also increase flood risks to others, not only by increasing surface water runoff rates but by obstructing or diverting flood flows and reducing flood storage. Planning permission should only be granted where specific criteria (Ref: page 124) are met.

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ES6.5 POLICY RECOMMENDATION 4 - Development involving building in areas identified as Functional Floodplain (Flood Zone 3b)

Development involving building in areas identified as Functional Floodplain in the SFRA will only be permitted in exceptional circumstances. Specific brownfield sites can be designated as Flood Zone 3a (high risk) and not part of the functional flood plain if agreed between the EA and the LPA.

ES6.6 POLICY RECOMMENDATION 5 - Sustainable Drainage Systems (SuDS)

The LPA will require developers to demonstrate that their surface water drainage proposals, particularly for large sites, are appropriate and adequate for the development and will not increase the flood risk to land and property either upstream or downstream of the development site. The Council considers that Sustainable Drainage Systems (SuDS) are a desirable means of achieving this and encourages their use by developers.

Planning permission for sites without SuDS will not usually be granted unless the Developer can provide sufficient justification as to why SuDS are inappropriate, unfeasible or unnecessary at the proposed development site.

ES6.7 POLICY RECOMMENDATION 6 - Culverting of Open Watercourses

LPAs and the EA will generally oppose the culverting of open watercourses because of the adverse ecological effects, potentially increased flood risk and other consequences that are likely to arise. Where practical in connection with the development proposals, LPAs should seek to have existing culverted watercourses restored to open channels, using planning conditions or S106 legal agreements.

ES6.8 POLICY RECOMMENDATION 7 - Climate Change

All new developments should take account of climate change in terms of both river flows and surface water run-off. River flows should be assumed to increase by up to 20% in 100 years and peak rainfall intensity by up to 30% depending on the lifetime of the development. Current guidance defines development lifetimes of 30 years for retail, 60 years for commercial/industry and 100 years for residential.

ES6.9 POLICY RECOMMENDATION 8 – Afforestation

Afforestation outside floodplains is beneficial and can reduce runoff and flood risk if undertaken in a sustainable manner. Opportunities for afforestation away from the immediate areas of watercourses should be considered, taken up and implemented wherever practical. Deforestation and other significant tree loss should be avoided, especially clear felling.

ES6.10 POLICY RECOMMENDATION 9 - Increased Impermeability

Increases in impermeable area requiring planning permission will not normally be permitted unless it can be demonstrated that the run-off from these areas will not be increased. This could be achieved by the following: • Sustainable drainage techniques such as permeable pavements and infiltration; • Underground storage and flow control.

ES6.11 POLICY RECOMMENDATION 10 - Runoff Rates

The LPAs will seek the maximum possible reduction in run off rates:- • For sites currently draining direct to sewer or watercourse and proposes to use the same outlet(s), a minimum of 30% reduction in peak discharge is required. Indirect drainage via the highway is not included in the calculation of existing flow. • For sites not currently drained or to be drained to alternative outlets, peak discharge to be restricted to a maximum of 5 litres per second per hectare

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ES6.12 Robust Council policy is essential to ensure that the planning recommendations can be imposed consistently at the planning application stage. This is essential to achieve future sustainability within each LPA area with respect to flood risk management.

Introduction

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1 Introduction

Faber Maunsell has been commissioned by Chesterfield Borough Council, Bolsover District Council and North East Derbyshire District Council to produce a Strategic Flood Risk Assessment (SFRA) to cover the three districts. The catchment area is shown in Figure 1. A joint study offers the benefit of reviewing flood risk and the potential for new development at a much wider scale. This recognises the nature of river catchments which cross administrative boundaries. Local Planning Authorities (LPAs) are encouraged to work in partnership to develop SFRAs at a sub regional level in national planning guidance. The SFRA is required to provide a sound and robust evidence base for the preparation of each LPA’s Local Development Framework (LDF). The LDF will comprise a portfolio of Local Development Documents which (together with the Regional Spatial Strategy) will provide the planning framework for the LPAs. The final SFRA will play a critical role in informing future planning decisions, policies, proposals and potential development sites with respect to all forms of flooding in the districts. This includes flooding from rivers and the sea, flooding from groundwater, land drainage, sewerage and other artificial forms of flooding. However, due to the catchment’s proximity to the sea, there is no risk from tidal flooding. The SFRA is based on the best available information at the time the study took place (September 2007). The SFRA has been undertaken and structured to meet the requirements of national planning policy in Planning Policy Statement 25: Development and Flood Risk (December 2006) and the accompanying ‘living draft’ Practice Guide (February 2007).1 Further details are provided in the methodology section of this report. 1.1 The need for a SFRA Flooding is a natural hazard that puts people’s lives at risk, causes immeasurable stress to the people affected and has an economic impact that can cost billions of pounds just from one event. Recent flooding in the UK (summer 2007) has emphasised the possible scale of flooding, in extent and impact, that can occur in the UK. However it should be remembered that flooding is a natural process which cannot be stopped altogether and therefore tackling flooding is more than just defending against floods. It means understanding the complex causes of flooding and taking co-ordinated action in partnership with others to reduce the impact of floods. Over the last century and in more recent times, pressures for development have resulted in the widespread development of floodplains. There is now increased pressure to develop in the floodplain but every effort should be made to ensure development only takes place in areas least at risk or constructed safely and not increasing risk either on the proposed site or elsewhere. Producing a SFRA will allow the LPA to make more informed judgements about potential development sites in the LDF, and decisions on planning applications. In relation to flood risk a SFRA will also allow the LPA to consider flooding on a catchment scale rather than on a case by case basis. Strategic decisions can therefore be made on where development is most appropriate in relation to flood risk, taking into account climate change. Guidance has been developed to enable the LPA to consider flood risk and drainage when considering strategic and site specific development. The government guidance in relation to flood risk is Planning Policy Statement 25: Development and Flood Risk (Communities and Local Government, Dec 2006) and Development and Flood Risk: A Practice Guide Companion to PPS25 ‘Living Draft’ (Communities and Local Government, Feb 2007).The latter has been replaced with PPS25: Development and Flood Risk – (June 2008). Section 2.2 provides more information on PPS25.

1 Updated by PPS 25 Practice Guide as this report was in its final draft stage.

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The PPS25 living draft requires that a SFRA should be carried out by the LPA to inform the preparation of its Local Development Documents (LDDs), having regard to catchment-wide flooding issues which affect the area. 1.2 SFRA Objectives The SFRA should provide sufficient data and information to enable the LPA to apply the Sequential Test to potential future development sites and, where necessary, the Exception Test. In addition, the SFRA should allow LPAs to:

 meet the requirements of Annex E, PPS25 and the living draft Companion Guide.  prepare appropriate policies for the management of flood risk within the LDDs  inform the sustainability appraisal so that flood risk is taken account within the wider context of sustainable development when considering options and in the preparation of strategic land use policies. This includes informing potential development sites through the LDF process.  identify the level of detail required for FRAs in particular locations, and  enable them to determine the acceptability of flood risk in relation to emergency planning capability. (PPS25) 1.3 Planning Policy Development Plan Documents are one part of a Local Authority’s (LA’s) Local Development Framework. LPAs are required, under the Planning and Compulsory Purchase Act 2004, to prepare a Local Development Framework (LDF). The LDF is made up of a portfolio of Local Development Documents (LDDs), which collectively delivers the spatial planning strategy for the LPA’s area. LDDs should reflect Government guidance regarding sustainable development. This includes the guidance within PPS25 Development and Flood Risk. This guidance aims to avoid placing new development, of a type which is incompatible with flooding, in areas at risk of flooding. LPAs should ensure that flood risk is taken into account at all stages of the planning process to avoid inappropriate development in areas at risk of flooding. Where new development is exceptionally necessary in such areas, the policies are to make it safe without increasing the risk elsewhere and where possible reducing overall risk. Key development planning tools that are used to implement PPS25 at different scales are summarised in Table 1. Table 1: Key development planning tools in PPS25 (taken from PPS25) Scale FRA techniques Decision-making tools Regional Spatial Strategy (RSS) Regional Flood Risk Appraisal Sequential Approach (RFRA) Local Development Documents SFRA and Area FRAs Sequential Test and Exception (LDDs) Test Individual Planning Applications FRA (including Drainage Impact Assessments)

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Figure 1: SFRA Study Area Showing Main Rivers

River Drone

River Whitting

River Hipper

River Doe Lea

River Amber River Rother

River Erewash

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Figure 2 shows the links between strategy documents (including flood and coastal defence documents) and SFRAs and also indicates who is responsible for them. Figure 2: Development planning process for flood risk (taken from PPS25 Practice Guide)

Notes 1 Including Planning Policy Statement 25 ‘ Development and Flood Risk ’ and the other flooding-related national planning policies listed in Appendix A of this Practice Guide. 2 SFRAs may cover more than one LPA, and the adoption of a catchment-based approach by a number of LPAs working in partnership could be highly beneficial. 3 This diagram has been developed from the original within Flood Risk Assessment Guidance for New Development Phase 2 R&D technical report FD2320/TR2 (Defra and EA, 2005).

1.3.1 Planning Policy Statement 25

PPS25 requires that a sequential approach to the location of new development is applied. This is done by the application of the Sequential Test (see Annex D of PPS25). The Sequential Test should aim to steer new development to Flood Zone 1(see section 2.3 of this report for Flood Zone definitions). Where there are no reasonably available sites in Flood Zone 1, taking into account the flood risk vulnerability of land uses, sites can be allocated in Flood Zone 2, applying the Exception Test if required. Only where there are no reasonably available sites in Flood Zones 1 or 2 should decision-makers consider suitability of sites in Flood Zone 3, taking into account the flood vulnerability of land uses and applying the Exception Test if required. The SFRA provides evidence to produce an initial Sequential Test for the potential future development sites provided by the LPAs. The SFRA also provides evidence which will allow the local authorities to assess any future development sites in terms of flood risk and produce their Local Development Documents. The evidence includes levels of flood vulnerability in Flood Zone 3 and the impact of climate change.

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1.3.2 Responsibility for LPA 1.3.2.1 A) Policy formulation / Local Development Framework Local Development Documents (LDDs) are mechanisms for ensuring that flood risk is factored into the detailed allocation of land use types across an area in accordance with national and regional policy, but also taking account of specific local issues and concerns. They provide an opportunity to provide clarification to prospective developers in the form of clear policies for the management of flood risk, as well as guidance on how flood risk issues should be addressed at sites allocated within flood risk areas. The Sequential Test and Exception Test should be applied in the site allocation process. The LDD should contain clear, strategic and robust policies for flood risk management. The SFRA should provide the basis for these policies. The Development Planning Document (DPD) and some Supplementary Planning Documents (SPDs) within the LDD should be informed, through the SFRA, of specific flood risk related issues that should be taken into account for certain potential future development sites. Figure 3 (see following page) from PPS25 further explains the process and links to the LDF. This SFRA includes flood risk policies and recommendations for sustainable drainage for sites (See Section 9). The SFRA also provides evidence for an initial Sequential Test for existing potential future development sites and information which should allow the LPA to perform the Sequential Test on any future potential development sites. Locations where the Exception Test is required are also identified. Advice on the necessary scope of a FRA is included in the SFRA as well as other flood risk issues to be considered. 1.3.2.2 B) Development control and planning applications The LPA is the principal decision-maker regarding applications for new development. LPAs should seek to engage in pre-application discussions with any developer expressing an interest in submitting a planning application for a site that is in an area at risk of flooding or which has potential to increase flood risk elsewhere. Specifically the LPA should:

 refer the developer to the SFRA and any planning policies of relevance to flood risk at the site, including policies or guidance on the application of sustainable drainage measures.  if the site is allocated for a particular use in the LDF, inform the developer as to whether the Sequential Test and/or Exception Test has already been applied through the site allocation process undertaken during preparation of the DPD. If the development site does not comply with the Sequential Test and/or Exception test, clarify the specific supporting information required to allow the LPA to apply the Sequential or Exception Test as part of the individual planning application process.  advise the developer on the need for a FRA and consultation with Environment Agency and/or other flood risk consultees.  set out and agree the scope for the FRA using the Environment Agency Standing Advice, or in direct consultation with the Environment Agency and any relevant flood risk consultees, as appropriate.  encourage pre-application discussions with the identified flood risk consultees (such as the Environment Agency) to ensure flood risk issues are resolved prior to submission of the planning application. This process is summarised in Figure 4 (see page 23) which is taken from PPS25’s practice guide.

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Figure 3: Process and links to the LDF from PPS25

Notes

1 Guidance on undertaking a SFRA can be found in Chapter 2 of this Practice Guide. 2 Guidance on developing the scope of SA can be found in ODPM (2005) Sustainability Appraisal of Regional Spatial Strategies and Local Development Documents. Guidance on suitable flood risk indicators can be found in FD2320, D2.1. 3 Flood Zone 1 for fluvial and tidal flooding and with a low risk of flooding from other sources. 4 Including an assessment of the potential effect of proposed development on surface water run-off. 5 Including consideration of the variability of flood risk within a Zone.

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Figure 4: Individual planning applications – guidance for developers from PPS25

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1.4 Methodology The SFRA is structured into four phases to meet the requirements of Annex E, PPS25 and the ‘living draft’ Companion Guide. Data Collection Data Collection and identifying areas at risk of flooding (theoretical and actual) from rivers, groundwater, land drainage, sewerage, and other artificial sources e.g. reservoirs and canals having regard to defences, topography and topographic features. A primary task of the SFRA was to evaluate all existing data, identifying any gaps or inadequacies in the datasets. The data collected and analysis completed has been used to inform the SFRA. Assessment of Flood Risk Assess the impact of external factors on flood risk including land management practices, climate change on flood risk for future horizons e.g. 25 year and 50 year flood risk zones, increased runoff and flood defence failure. Flood risk locations have been collected and mapped. In addition, any other information such as historic flood outlines and defended areas have been collected and mapped. Climate change flood extents have been produced where information is available. The level of risk within flood extents and the level of hazard to people will be assessed where there is existing modelling data to do so. More details on the maps produced can be seen in section 6.1. In addition, further information on the types of flood mapping available is in Section 2.3 It is necessary to identify areas of flood risk outside of Flood Zones 2 and 3. PPS25 requires that FRAs look at all sources of flood risk not just from fluvial sources. During the SFRA information on flood risk problem locations has been collected from knowledge holders in the Environment Agency, LPAs, and water companies. This information has been put into a database, each entry has a reference. These locations have been mapped in GIS so that it can be seen if a potential development site could be at risk from one of these other sources of flood risk. Assessment of mitigation measures Consultation with the Environment Agency and the LPA to ensure that policies are drafted with regard to their procedures and policies for responding to Flood Risk Assessments. The SFRA has been completed in close communication with the Environment Agency. The Environment Agency attended progress meetings where technical issues have been discussed. The Environment Agency has also been available throughout the study for guidance to ensure the SFRA is completed in line with their objectives for flood risk management and planning. This also includes the development of flood risk policies for the LPAs. Reporting and providing guidance Reporting which includes the preparation of a matrix of flood risk in each area (which icludes recommendations on mitigation measures to bring development forward), identification of ongoing or further analysis necessary to build on and reinforce the knowledge base. A flood risk matrix has been developed. This lists current housing, employment and major mixed use development sites and assesses them against all the information gathered. This includes flood extents, historic flood maps, flood defences, flood risk locations from other sources and flood hazard. The matrix will form the basis for further analysis by the LPA of future potential development sites being considered for the LPA’s LDF. This is included in the addendum of this SFRA. 1.5 The Study Area The main population centres in the Study Area are Chesterfield, Bolsover, Dronfield, Shirebrook, South Normanton, Clowne, Creswell, Renishaw, Killamarsh, Staveley, Clay Cross and Eckington, although there are also numerous other villages (See Figure 1). A number of rivers serve the area namely the Rother, Hipper, Doe Lea, Drone, Whitting, Erewash and Amber and tributaries. In addition, the Trust has been active in restoring a section of the Chesterfield Canal between Chesterfield and Staveley.

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Most rivers drain northwards into the River Rother ultimately flowing into the River Don, with the main exceptions being the which drains south into the River Derwent, and the River Erewash which drains south to the . The Rother is an extensively managed river to protect downstream communities including and Doncaster. The EA’s model of the river should reflect the operation of the river in relation to flood risk. As stated in Section 1, SFRAs are required to consider all aspects of flooding. The floods of July 2007 in , North East Derbyshire, and the Midlands have further highlighted the need to include an assessment of flooding at all levels of the planning process. The locations of historical flooding have been considered as part of this report. Flood risk issues from reservoirs were also graphically illustrated with the near failure of the Ulley Dam in the Rotherham area and flooding from surface water drainage was evidenced in many areas, for example Chesterfield and Killamarsh. The Regional Flood Risk Appraisal states that only Chesterfield (of the three councils) expects any development to take place on Flood Risk Zone 3 land. In central Chesterfield a few development sites have been identified which are partly brownfield land and partly in Flood Zone 3. It is stated in the RFRA that the intention of these regeneration schemes will not include built development on those sections of the sites identified as lying within Flood Zone 3 and will attract developer contributions to flood management schemes.

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Flood Risk

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2 Flood Risk

In the study area flood risk predominantly arises from fluvial (rivers and watercourses) sources. Fluvial flooding occurs as a result of the overflowing or breaching of river or stream banks when the flow in the watercourse exceeds the capacity of the river channel to accommodate that flow. It is also becoming increasingly important to consider flood risk from other sources. These include groundwater, (notably springs from limestone, sandstone and chalk aquifers), land drainage (low lying areas and runoff from steeply sloped areas), sewerage, and other artificial sources e.g. reservoirs and canals. In Chesterfield, Bolsover, and North East Derbyshire there are many different types of flood risk present with the exception of tidal flooding. In some areas changes to land use patterns may be appropriate. Coordination of strategies and plans is crucial, and flood warning, appreciation of vulnerability, and a whole range of mitigation measures are essential if sustainable flood risk management is to be achieved. As has been illustrated by recent events (e.g. in Summer 2007) flooding can occur virtually anywhere although much flooding was local, rather than strategic in origin and impact. Flooding locations depend very much on the profile and duration of the storms which cause them and on local factors such as blocked drains and culverts, breaches or failure of defences and local topography. Therefore, safety from flooding can never be guaranteed. Flooding may occur in locations which appear to be at relatively low risk compared to others.

In the Chesterfield, Bolsover, and North East Derbyshire areas the most serious (and predictable) flooding is still usually from river systems (Main Rivers and Ordinary Watercourses – see glossary for definition).

2.1 Responsibilities Whilst the Environment Agency is the main authority responsible for developing flood risk management strategies and policies, LPAs, Internal Drainage Boards (IDBs) and Water Companies all have a part to play in achieving the government’s aims and objectives. Developers also have a responsibility to protect their land from natural hazards which includes flooding and managing land drainage. Landowners have the primary responsibility for draining their land and managing the flood risk issues associated with their property. The owners of assets such as canals and reservoirs (e.g. British Waterways Board, Chesterfield Canal Trust, Severn Trent Water and private owners) are similarly responsible for managing the flood risk issues associated with them. 2.1.1 Department for Environment, Food and Rural Affairs (Defra) Defra has overall policy responsibility for flood and coastal erosion risk in . It funds most of the Environment Agency’s activities in this area and provides grant aid to the other flood and coastal defence operating authorities (LPAs and IDBs) to support their investment in improvement works. Improvement projects funded by Defra, including those of the Environment Agency, must meet specified economic, technical and environmental criteria and achieve an appropriate “priority score” to be eligible for funding. Defra does not build defences, nor does it direct the authorities on what specific projects to undertake. 2.1.2 The Environment Agency The Environment Agency was established by the Environment Act 1995 and is a Non- Departmental Public Body of Defra. The Environment Agency took over the flood risk management responsibilities of the now defunct National Rivers Authority (NRA) and is the principal flood risk management operating authority in England and Wales. The Environment Agency is empowered under the Water Resources Act 1991 to manage flood risk arising from designated main rivers and the sea. The Environment Agency is also responsible for flood forecasting and flood warning dissemination, and for exercising a general

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supervision over matters relating to flood defence. The review of “Making Space for Water” is currently considering a strategic overview role for the Environment Agency for all flood and coastal erosion risk management issues. The Environment Agency has statutory powers to manage flood risk to existing properties and assets. At a strategic level, it provides Regional Planning Bodies (RPBs) and LPAs with advice on the preparation of Regional Flood Risk Assessments (RFRAs) and SFRAs.

The Environment Agency is a statutory consultee for Regional Spatial Strategies (RSSs), Local Development Documents (LDDs), Sustainability Appraisals (SAs), Strategic Environmental Assessments (SEAs) and for planning applications. The Environment Agency should be consulted on all proposed developments in Flood Zones 2 or 3 and any development over 1 hectare in all Flood Zones. It should also be considered for culverting issues and other known land drainage problems (reference PPS25 and the living guide).

The Environment Agency’s role at the pre-application stage will generally involve provision of relevant flood risk information and advice, as well as comments on the scope of Flood Risk Assessments. The Pitt Review (June 2008) recommends a wider role for the Environment Agency in terms of oversight of flood risk management. 2.1.3 Local Authorities

Local Authorities are responsible for ordinary watercourses (watercourses which have not been designated as main and which are not within internal drainage board areas) and have powers to undertake flood defence works under the Land Drainage Act 1991.

Sometimes the riparian owners have the responsibility for works which would be identified by the LA. The LA has permissive powers to maintain ordinary watercourses but, as for main rivers, responsibilities to do so rest with the riparian owner. A LA may have responsibilities for coastal erosion and flood risk management if it has been assigned as a Maritime District Council under the Coastal Protection Act 1949. The LPA has a responsibility for considering and minimising flood risk in developing planning policies/proposals and in determining planning applications in line with PPS25 (further details are contained in 1.3.2). 2.1.4 Water and Sewerage Undertakers

Water Companies and sewerage undertakers are responsible for surface water drainage from development via adopted sewers (adopted under the requirements of the Water Industry Act 1991) and in some instances Sustainable Drainage Systems (SuDS).

The Water Companies covering the three Districts are Severn Trent and Yorkshire Water. They prepare Asset Management Plans (AMPs) approved by the water regulator, Ofwat, which include investment programmes to manage the flood risk from sewers. Water companies are not responsible for the maintenance of highway drainage systems. Responsibility for the maintenance of private drainage systems lies with the highway authority wherever these are not privately owned. Water Companies should ensure that their plans for urban drainage reflect the appropriate Regional Spatial Strategies (RSSs) and Local Development Documents (LDDs) in line with their obligations in the current legislation and their AMPs. LPAs should consult sewerage undertakers in developing their spatial plans, as soon as possible in the LDF process so that their SFRA takes account of any specific capacity problems and of the undertaker’s Urban Drainage Plans. Developers should consult their local sewerage undertaker on surface water disposal issues.

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2.1.5 Internal Drainage Boards Internal Drainage Boards (IDBs) are independent bodies, created under statute to manage land drainage in areas of special drainage need and are empowered under the Land Drainage Act 1991. There are some 170 boards in England, concentrated in the lowland areas of East Anglia, Somerset, Yorkshire and . Each board operates within a defined area in which they undertake flood defence works on watercourses that have not been designated as "main". IDB membership includes elected members representing the occupiers of the land in the district and members nominated by LPAs to represent other interests.

There are no areas in Chesterfield, Bolsover or North East Derbyshire that are covered by an IDB.

2.1.6 Highways Authorities Local highways authorities have responsibility for managing road drainage from roads on the local road network, in so far as ensuring that drains which are their responsibility are maintained. The Highways Agency is responsible for managing road drainage from the trunk road network in England, including the slip roads to and from trunk roads.

Section 41 of the Highways Act 1980 imposes a duty upon the Highway Authority to maintain those roads which are maintainable at public expense. Section 100 of the Highways Act 1980 empowers the Highway Authority to construct, maintain or cleanse drainage systems in the highway or on adjoining/nearby land, for the purpose of drainage or prevention of surface water on the highway.

2.1.7 Reservoir Undertakers Under the Reservoirs Act 1975, reservoirs impounding over 25,000m 3 of water above natural ground level are categorised on a risk basis according to the consequences (in terms of potential for loss of life and/or damage to property) of a structural failure occurring. LPAs should discuss their potential future development sites with reservoir undertakers to:

 avoid an intensification of development within areas at risk from reservoir failure  ensure that reservoir undertakers can assess the cost implications of any reservoir safety improvements required due to changes in land use downstream of their assets. Certain reservoir undertakers will be required to produce emergency contingency plans (Flood Plans), following direction by the Secretary of State under the Reservoirs Act 1975, as amended. This requirement will be introduced following consultation by Defra. The presence of reservoirs and implications for flood risk should be recognised in Regional Flood Risk Assessments (RFRAs), SFRAs and Flood Risk Assessments (FRAs). FRAs should take into account information received from the reservoir undertakers and flood plans when they are available and relevant. Where the consequences of dam failure could endanger life, a reservoir has to be designed to cope with floods of greater severity than those where the consequences of failure would have negligible risk to life. It follows that proposed development downstream could have cost implications if it required upgrading works for the reservoir. There are a number of reservoirs in the CBC, BDC, and NEDDC area. A few of them are upstream of potential development sites and therefore there is a flood risk to future properties should development take place. 2.1.8 British Waterways British Waterways should be consulted by the LPA and developers in relation to sites adjacent to canals, especially where these are impounded above natural ground level. This is stated in Section 1.62 of PPS25 Practice Guide (PPS25) 2.1.9 Emergency Services and Multi-agency Emergency Planning The Civil Contingencies Act 2004 and associated Regulations sets out an emergency preparedness framework, including planning for and response to emergencies. Local Resilience Forums, which include representatives from the Emergency Services, LPAs and the

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Environment Agency, should ensure that risks from flooding are fully considered, including the resilience of emergency infrastructure that will have to operate during floods. Emergency Services should be consulted during the preparation of LDDs. In some cases, it may be appropriate for the LPA to consult the emergency services themselves on specific emergency planning issues related to new developments. 2.1.10 The Developer PPS25 states that it is the responsibility of developers to consider carefully the flood risk issues at a site as early as possible. The Environment Agency on-line Flood Maps and the SFRA should provide some indication of whether a site is at risk of flooding. However developers should make independent checks prior to purchasing sites. A developer is not required to apply the Sequential Test if a proposed development is located on a site which has been allocated for that type of development in a LDD that has been sequentially tested and supported by a SFRA. However, the developer should still apply the sequential approach to any flood risk within the site itself when determining the location of appropriate land uses. In any areas where flood risk has been identified as an issue, developers should liaise with the LPA to agree on who should be consulted. The scope of any FRA should be agreed with the LPA, and if necessary, in consultation with the Environment Agency. This SFRA provides guidance on who needs to be consulted for a specific set of circumstances (see Section 8.6 and Appendix C). 2.2 Planning Policy Statement 25 Planning Policy Statement 25 (PPS25) defines four zones of flood risk. These zones are based on the quantified degree of flood risk to which an area of land and buildings is subject at the time at which a land allocation decision is made or a planning application submitted. The PPS25 flood risk zones and their associated fluvial flood risk characterisations are summarised in Table 2 below: Table 2: PPS25 Flood Zones (taken from PPS25) Zone 1 Low Probability This zone comprises land assessed as having a less than 1 in 1000 annual probability of river or sea flooding in any year (<0.1%).

Zone 2 Medium Probability This zone comprises land assessed as having between a 1 in 100 and 1 in 1000 annual probability of river flooding (1% – 0.1%) or between a 1 in 200 and 1 in 1000 annual probability of sea flooding (0.5% – 0.1%) in any year.

Zone 3a High Probability This zone comprises land assessed as having a 1 in 100 or greater annual probability of river flooding (>1%) or a 1 in 200 or greater annual probability of flooding from the sea (>0.5%) in any year.

Zone 3b The Functional Floodplain This zone comprises land where water has to flow or be stored in times of flood. SFRAs should identify this Flood Zone (land which would flood with an annual probability of 1 in 20 (5%) or greater in any year or is designed to flood in an extreme (0.1%) flood, or at another probability to be agreed between the LPA and the Environment Agency, including water conveyance routes).

The PPS25 flood risk zones give a broad indication of flood risk. However, most areas which fall within the high risk zone (Zone 3) are on flood plains and many such areas already enjoy some degree of protection from established flood defences. The actual degree of flood risk to which these areas are subject may well be significantly less than that implied by their PPS25 classification, provided of course that those defences are maintained.

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PPS25 requires LPAs to adopt a risk-based approach to development in areas at risk of flooding, and to apply a "Sequential Test" to such areas (see Figure 4). This means that, other factors being equal, the LPA would favour development in areas with a lower flood risk. It is clear that study areas within the PPS25 "high risk" zone may be at very different risks of flooding. For example, whereas the probability of flooding in one area may be as high as 10% (1 in10 years) the probability in a neighbouring area may be as little as 2% (1 in 50 years), yet both are within PPS25 Zone 3. The LPA must therefore be able to rank study areas according to actual flood risk (based on a knowledge of Standards of Protection (SoP – see glossary ) and condition of the defences). As shown in Table 2, PPS25 Zone 3 is subdivided into two areas, 3a and 3b. Zone 3b is classed as functional floodplain and is defined as being at risk from the 1 in 20 year flood or greater. PPS25 also states that the following types of development may be allowed.

 3a: Water-compatible and less vulnerable uses of land in Table D.2 of PPS25 are appropriate in this zone. More vulnerable development is allowed subject to the Exception Test. Table 3 describes the types of development.  3b: Only the water-compatible uses and the essential infrastructure listed in Table 3 that has to be there should be permitted in this zone. Essential infrastructure in this zone should pass the Exception Test. The Practice Guide Companion to PPS25 gives further guidance on the definition of Flood Zone 3b and allows flexibility to subjective interpretation. More specifically it states that areas, which would be subject to flooding in the 5% (1 in 20 year) annual exceedence probability flood event but where the flow of flood water is prevented by existing infrastructure or by solid buildings or other solid barriers, will not normally defined as Flood Zone 3b. Based on the above guidance, specific brownfield sites can be designated as Flood Zone 3a (high risk) and not part of the functional floodplain (Flood Zone 3b) if agreed between the EA and LPA. All types of development may be acceptable in Flood Zones 1 and 2 apart from highly vulnerable development in Flood Zone 2 for which the Exception Test is required. 2.2.1 The Sequential and Exception Tests Annex D of PPS25 provides clear guidance on application of the sequential approach in relation to flood risk. This approach is a simple decision-making tool designed to ensure that sites at little or no risk of flooding are developed in preference to areas at higher risk. It can be applied at all levels and scales of the planning process, both between and within Flood Zones.

All opportunities to locate new water-incompatible developments in reasonably available areas of little or no flood risk should be explored, prior to any decision to locate them in areas of higher risk. Potential sites for new housing can be considered ‘reasonably available’ if the ‘available’ part of the criteria set out in Housing Land Availability Assessments: Identifying land for residential development (ODPM; 2005) is, or is reasonably expected to be met within five years of the LDD or planning application submission.

2.2.2 The Sequential Test The sequential test is applied by the LPA to ensure that any potential development sites are compatible with the level of flood risk in that location and the vulnerability of the proposed development. It aims to ensure that more and highly vulnerable development types (such as residential housing) will not be allocated at areas of high risk of flooding. Through the LDF development site process, development should be directed to Flood Zone 1 wherever possible, and then sequentially to Flood Zones 2 and 3, and to the areas of least flood risk within Flood Zones 2 and 3, as identified by the SFRA. It is recognised that some applications for development will still be made on sites that have not been allocated (i.e. windfall sites). Such windfall sites will also be subject to the sequential test and/or exceptions test to steer the proposed development away from areas most at risk of flooding.

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Table 3: Flood Risk Vulnerability Classification from PPS25 (taken from PPS25)

 Essential transport infrastructure (including mass evacuation routes) which Essential has to cross the area at risk, and strategic utility infrastructure, including Infrastructure electricity generating power stations and grid and primary substations.

 Police stations, Ambulance stations and Fire stations and Command Centres and telecommunications installations required to be operational during flooding. Highly  Emergency dispersal points. Vulnerable  Basement dwellings.

 Caravans, mobile homes and park homes intended for permanent residential use.  Installations requiring hazardous substances consent.

 Hospitals.  Residential institutions such as residential care homes, children’s homes, social services homes, prisons and hostels.  Buildings used for: dwelling houses; student halls of residence; drinking establishments; nightclubs; and hotels. More  Non–residential uses for health services, nurseries and educational Vulnerable establishments.  Landfill and sites used for waste management facilities for hazardous waste.  Sites used for holiday or short-let caravans and camping, subject to a specific warning and evacuation plan .

 Buildings used for: shops; financial, professional and other services; restaurants and cafes; hot food takeaways; offices; general industry; storage and distribution; non–residential institutions not included in ‘more vulnerable’; and assembly and leisure. Less  Land and buildings used for agriculture and forestry. Vulnerable  Waste treatment (except landfill and hazardous waste facilities).  Minerals working and processing (except for sand and gravel working).  Water treatment plants.  Sewage treatment plants (if adequate pollution control measures are in place) 

 Flood control infrastructure.  Water transmission infrastructure and pumping stations.  Sewage transmission infrastructure and pumping stations.  Sand and gravel workings.  Docks, marinas and wharves.  Navigation facilities. Water-  MOD defence installations. compatible  Ship building, repairing and dismantling, dockside fish processing and Development refrigeration and compatible activities requiring a waterside location.  Water-based recreation (excluding sleeping accommodation).  Lifeguard and coastguard stations.  Amenity open space, nature conservation and biodiversity, outdoor sports and recreation and essential facilities such as changing rooms.  Essential ancillary sleeping or residential accommodation for staff required by uses in this category, subject to a specific warning and evacuation plan .

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Some adopted CBC, BDC, and NEDDC Local Plan policies/allocations may not have been subject to the sequential test under PPS25, as these policies pre-date the publication of PPS25. In such instances, the sequential test should also be considered in the determination of planning applications. This applies both in the site location and the sequential approach to development within the site itself. In these instances, it is the responsibility of the developer to provide the relevant evidence to be considered by the LPA in the determination of the planning application .

2.2.3 The Exception Test Following the application of the sequential test, in exceptional circumstances, there may be valid reasons for a development type which is not entirely compatible with the level of flood risk at a particular site to nevertheless be considered as it would deliver wider sustainability benefits. To meet the Exception Test the developer should demonstrate the wider sustainability benefits that outweigh the flood risk implications of developing the site (see below). It is recommended that the LPA develop a sustainability checklist to assess such sustainability benefits. This should be based on the aims and objectives of their SA Framework used in assessing the LDD.

The Exception Test should only be applied following application of the Sequential Test. There are three stringent conditions, all of which must be fulfilled before the Exception Test can be passed. These conditions are as follows: a) 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 Development Plan Document (DPD) has reached the ‘submission’ stage (see Figure 4.1 of PPS12: Local Development Frameworks) the benefits of the development should contribute to the Core Strategy’s Sustainability Appraisal (SA); b) 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 developable previously-developed land; and c) a site-specific Flood Risk Assessment must demonstrate that the development will be safe, without increasing flood risk elsewhere, and, where possible, will reduce flood risk overall.

Figure 5 shows whether the Sequential or Exception Test will be required for a development type in a Flood Zone.

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Figure 5: Flood Risk Vulnerability and Flood Zone ‘Compatibility (taken from PPS25 1) Flood Risk Vulnerability Essential Water Highly More classification Less Vulnerable Infrastructure Compatible Vulnerable Vulnerable (see Table D2 PPS25 Annex D) Zone 1      Exception Zone 2   Test   required Exception Exception Test Zone 3a   Test  required required

Zone 3b Exception Test ‘Functional     required Floodplain’ Flood Zone (see Table D.1 PPS25 D.1PPS25 Table (see Zone Flood D Annex

 Development is appropriate

 Development should not be permitted Chapter 3 of PPS25’s practical guide (PPS25 2) provides more details of the Sequential and Exception Tests. 2.3 Flood Mapping Only two forms of flood maps are currently available: Flood Zone maps and flood maps. The differences between these is highlighted in the following table and described more fully in the following sections. Table 4: Flood Map Types Prospective Use Map Type Description

Flood Zone These were prepared using nationally Flood Zone maps are not readily (‘FZ’)Maps consistent methodologies for the accessible to the general public or those determination of flood risk zones for wishing to undertake detailed flood risk fluvial flooding. The FZ maps show both assessments. PPG25 Flood Risk Zones 2 and 3. The FZ maps also exclude the effect of Access to the FZ maps for a specific existing flood defences. area must be sought by way of the relevant LPA. The FZ maps are not limited to Main River floodplains but include the floodplains of all watercourses with a catchmen t area of more than 3 sq.km. Flood Maps Available on the internet and issued at They are not intended, at this stage, to 1/50,000 scale these maps are intended supersede the larger scale and more for use by the general public. detailed Flood Zone maps issued to LPAs but to be used in conjunction with them. Note: See discussion in 2.3.2 paragraph

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2.3.1 Flood Zone Maps Following a comprehensive fluvial flood risk mapping exercise carried out across the country, the Environment Agency issued a set of Flood Zone Maps to each LPA in England and Wales during Summer 2004 covering the whole of that authority’s area in electronic format. The CBC, BDC, and NEDDC Flood Zone Maps were made available to Faber Maunsell by the LPAs. The Flood Zone (FZ) maps were prepared using nationally consistent methodologies for the determination of flood risk zones for fluvial flooding. The FZ maps show both PPG25 Flood Risk Zones 2 and 3. The FZ maps also exclude the effect of existing flood defences. The Flood Zone maps, are based on OS 1/10,000 scale maps and include the floodplains of all watercourses with a catchment area of more than 3 sq.km. Flood Zone maps are not readily accessible to the general public or those wishing to undertake detailed flood risk assessments. Those wishing to consult the FZ map for a specific area must do so through the relevant LPA or the EA. FZ maps are not made available by the Environment Agency other than through LPAs if they are asked by a developer for specific information on a site. 2.3.2 Flood Maps In October 2004 the Environment Agency issued a further set of flood risk maps covering all of England and Wales. These maps, issued only at 1/50,000 scale, were intended for use by the general public and are available on the internet. They are not intended, at this stage, to supersede the larger scale and more detailed Flood Zone maps issued to LPAs but to be used in conjunction with them. These Flood Maps show two flood risk zones; a dark blue zone in which annual flood risk probabilities are defined as greater than 1% for fluvial flooding, and a light blue zone in which the annual flood risk probability is greater than 0.1%. Like the FZ maps, the dark and light blue areas show the potential extent of flooding without defences. Flood defences (and defended areas) are shown where those defences are less than five years old and give a 1% fluvial standard of protection. If the user clicks on a dark blue or light blue area an assessment of flood risks is provided, as follows: “Significant” annual probability >1.3% (once in less than 75 years) “Moderate” annual probability between 1.3% and 0.5% (1 in 75 to 200 years) “Low” annual probability (1 in >200 years) or less. This provides an indication of the likelihood of flooding in the user’s area. This came from a national flood risk assessment completed in 2005, which used ground levels, predicted flood levels, information on flood defences, and the EA’s local knowledge. The likelihood is described in one of three categories, low, moderate or significant, as used by the insurance industry. This assessment should not be used for preparing a flood risk assessment. It should be noted that the 1.3% (1 in 75 years) and 0.5% (1 in 200 years) annual probability levels for this classification correspond to levels currently adopted by the British Insurance Association and not that used in PPS25. The Environment Agency proposes to update the Flood Maps on a three-monthly basis in order to ensure that the maps reflect the latest assessments of flood risk and to remove anomalies. At some locations, for example, it is possible to “click on” to a dark blue area on the map where no flood defences exist and where flooding is known to occur and obtain a “Low” flood risk classification.

Data Collection

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3 Data Collection

A primary task of the SFRA is to evaluate all existing data, identifying any gaps or inadequacies in the datasets. The data collected and analysed has been used to inform the SFRA. A summary of the key data sets is presented below 3.1 Flood Zone maps The Flood Zone maps are described in Chapter 2. These maps were obtained from each LPA in GIS format. The Flood Zone maps are supplied to the LPAs by the Environment Agency and they describe areas considered to be at a potential risk from fluvial flooding. 3.2 Topography Light Detection and Ranging (LiDAR) data was available for all of the Chesterfield area but only small parts of the Bolsover and North East Derbyshire districts. The Environment Agency procures LiDAR data and has provided it to Faber Maunsell for use in this study. The LiDAR extent available covered the majority of the main rivers and the main urban areas. The LiDAR data has a vertical accuracy of +/- 0.25m and the intention was to use the data to map fluvial flood extents for the climate change scenario (based on flood data provided by the Environment Agency models). 3.3 Hydraulic Models Hydraulic models are constructed to accurately estimate flood levels within a river catchment. Existing hydraulic models available within the study area were requested in order to determine the following:

 The extent of the functional floodplain  The extent of Flood Zone 3 (areas at risk from up to the 1 in 100 year fluvial flood)  The extent of Flood Zone 2 (areas at risk from between the 1 in 100 and 1 in 1000 year fluvial flood)  The likely effect of climate change. Two separate hydraulic ISIS models are available within the study area and have been provided by Halcrow (on behalf of the EA). One model covers the River Rother upstream of Whittington gauging station, , Holme Brook and the unnamed watercourse at Storforth Lane. The second model covers the River Doe Lea and its tributaries the Pools Brook and Hawke Brook. The hydraulic models have been used to define the extent of the functional floodplain, where this data was available. Functional floodplain is defined as areas being at risk from the 1 in 20 year return period storm. The hydraulic models contained the 1 in 25 year return period storm, which was considered suitable for this exercise. It was intended to use the hydraulic models to define the extent of Flood Zone 3 and predict the likely affect of climate change; by increasing the flow by 20%. The results from the hydraulic models were analysed and compared against the 100 year flood levels supplied by the EA. It was determined that the flood levels taken from the model did not correlate with the flood levels provided by the EA (in general the EA figures were significantly higher). The flood levels predicted by the Halcrow model are less conservative than those from the EA due to the incorporation of flood alleviation schemes and flood defences which change the hydraulics of the system. The EA confirmed that, as the information provided by the EA represents a more conservative estimate, this data should be used to define Flood Zone 3 and not the hydraulic models. Also, as no matching base data has been made available for comparison it has been deemed inappropriate to use the models to predict the likely affect of climate change (as the results would indicate a reduction in flood risk rather than an increase). There was no modelling available for the 1 in 1000 year storm and, as such, the Environment Agency’s Flood Zone 2 map has been used. Flood extents from the June 2007 flood were provided by Chesterfield Borough Council and it has been confirmed by the EA that these

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extents will now define the Flood Zone 2 outline. However, it should be noted that the flood extents have been obtained by aerial photography only and may not take account for secondary factors such as blocked culverts etc. As such, these flood extents should be used with caution. 3.4 Flood Alleviation Schemes The following proposed flood alleviation schemes are currently at a feasibility stage:

 Tin Wood on the River Hipper  The Avenue Project on the River Rother Future flood alleviation schemes should not be considered when assessing current flood risk policy as there is no guarantee they will go forward to completion or what standard of protection will be ultimately provided. It will be the responsibility of the developer to review the status of ongoing flood alleviation schemes. In respect of the Avenue site it is proposed that there will be remediation works within the functional floodplain and eventually the construction of an earth embankment dam that will create a flood storage area. For both the Tin Wood and Avenue site the functional flood plain could be subject to change as a result of future work. 3.5 Historic flooding Historic flooding information has been collected from a variety of sources as follows:

 Interviews with LPA drainage engineers for Chesterfield, Bolsover and North East Derbyshire  Environment Agency records  June 2007 flood extents (provided by the EA)  High level DG5 data from Severn Trent Water and Yorkshire Water (see section 3.9.3) Details of historical flooding and flood risk locations are reviewed in Chapter 5 and Appendix A. 3.6 Defences The Environment Agency’s National Flood and Coastal Defence Database (NFCDD) is considered to be the primary source of flood defence and asset survey information. NFCDD is able to provide details of the type and location of flood defences within the catchment, together with their associated design standards of protection, age, physical condition and the parties responsible for ownership and operation. As well as raised defences (e.g. earth embankments) the NFCDD information received also holds spatial and descriptive data on culverts, flood defence structures (e.g. weirs), maintained channels and non flood defence structures (e.g. pipe crossings). The natural river banks for the main rivers are also given a return period standard of protection (see glossary) and in some cases a bank height. The location and extent of raised man-made flood defences across the catchment are illustrated on the following drawings: Drawing Name Drawing Number Historic Flooding, Flood Storage and Defences - Chesterfield Overview 55328/C/HF/O Historic Flooding, Flood Storage and Defences - Chesterfield Area 01 55328/C/HF/01 Historic Flooding, Flood Storage and Defences - Chesterfield Area 02 55328/C/HF/02 Historic Flooding, Flood Storage and Defences - Chesterfield Area 03 55328/C/HF/03 Historic Flooding, Flood Storage and Defences - Bolsover Overview 55328/B/HF/O Historic Flooding, Flood Storage and Defences - Bolsover Area 01 55328/B/HF/01 Historic Flooding, Flood Storage and Defences - Bolsover Area 02 55328/B/HF/02 Historic Flooding, Flood Storage and Defences - Bolsover Area 03 55328/B/HF/03 Historic Flooding, Flood Storage and Defences - Bolsover Area 04 55328/B/HF/04 Historic Flooding, Flood Storage and Defences - Bolsover Area 05 55328/B/HF/05 Historic Flooding, Flood Storage and Defences - Bolsover Area 06 55328/B/HF/06 Historic Flooding, Flood Storage and Defences - Bolsover Area 07 55328/B/HF/07 Historic Flooding, Flood Storage and Defences - Bolsover Area 08 55328/B/HF/08 Historic Flooding, Flood Storage and Defences - Bolsover Area 09 55328/B/HF/09 Historic Flooding, Flood Storage and Defences - Bolsover Area 10 55328/B/HF/10 Historic Flooding, Flood Storage and Defences – North East Derbyshire Overview 55328/B/NE/O Historic Flooding, Flood Storage and Defences – 55328/NE/HF/01 North East Derbyshire Area 01

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Historic Flooding, Flood Storage and Defences – 55328/NE/HF/02 North East Derbyshire Area 02 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/03 North East Derbyshire Area 03 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/04 North East Derbyshire Area 04 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/05 North East Derbyshire Area 05 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/06 North East Derbyshire Area 06 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/07 North East Derbys hire Area 07 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/08 North East Derbyshire Area 08

The remaining assets and structures are shown on the following drawings: Drawing Name Drawing Number Assets - Chesterfield 55328/C/AS/O Assets - Bolsover Overview 55328/B/AS/O Assets - Bolsover Area 01 55328/B/AS/01 Assets - Bolsover Area 02 55328/B/AS/02 Assets - North East Derbyshire Overview 55328/NE/AS/O Assets - North East Derbyshire Area 01 55328/NE/AS/01

The majority of the defences are along the River Whitting, River Hipper, River Rother and River Doe Lea, and are located at the main flood risk areas such as Chesterfield. The types of defences include steel piled walls, concrete walls, retaining walls, flood walls, and concrete or earth embankments. The majority of the defences within the study area have an indicative standard of protection (SoP) of either 30 or 50 years, which means that none of these defences meet the 1 in 100 year standard of protection from fluvial flooding. As such, in planning terms, developments behind these defences, which are located in Flood Zone 3, cannot be treated any differently due to the presence of the flood defence (as they are still at risk from the 1 in 100 year flood). However, the defences will reduce the frequency of flooding at these development sites. The NFCDD data provided by the Environment Agency needs to be treated with extreme caution. This system has a vast amount of data that has been uploaded but will require verification. The Standard of Protection (SoP) is a target standard for maintenance and inspection of man-made structures or raised ground. In some cases the input data for the SoP is displayed as a 1 in 100 year standard, which is a system default unless altered. Examples of this error are on Aftreton Brook and the River Drone in NEDDC area. For site-specific FRAs verification must be sought from the Environment Agency for any SoP value displayed in this SFRA. 3.7 Flood warning The Environment Agency operates a fluvial flood warning service for the River Rother covering Chesterfield, the western part of Bolsover and the northern part of North East Derbyshire. A study reviewed the flood warning arrangements for the River Rother catchment and proposed new Flood Warnings was prepared by the EA in November 2003 and was updated in light of June 2007 flooding. During the course of the study, telemetry stations were installed. The Upper Rother study mapped outlines for return periods as short as 5 years. Trigger levels for Flood Watch, Flood Warning and Severe Flood Warning have been set using hydrographs from the Don Catchment Flood Model. The flood warning service includes the following watercourses: River Rother upstream of Whittington, River Hipper, Holme Brook and River Doe Lea and tributaries upstream of Staveley, River Erewash and Pinxton. The flood warning area extends between and Killamarsh and consists of properties, industrial units, and agricultural land. This fluvial flood warning area ends before Meadowgate Lake at Killamarsh. Table 5 summarises the Flood Warning service provided by the Environment Agency in the CBC, BDC and NEDDC areas, with the locations shown on the EA Figures in Appendix D.

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Table 5: Flood Warning Areas in Chesterfield, Bolsover and NE Derbyshire Flood Warning Return Flood Warning Area River/Brook Area Code Period RW477U Holme Brook at Ashgate Holme Brook 100 RW476U River Hipper at Central Chesterfield River Hipper 100 RW463U River Rother at Tapton River Rother 100 RS462 River Rother at Central Chesterfield River Rother 50 RS469 River Rother at Killamarsh River Rother 100 RS475 River Hipper at Brampton River Hipper 75 RW460 River Rother at Birdholme River Rother 100 RW461 River Rother at Central Chesterfield River Rother 10 RW463 River Rother at Tapton River Rother 10 RW464 River Rother at Brimington River Rother 100 River Rother at Staveley Business RW465 River Rother 100 Centre RW466 River Rother at Renishaw River Rother 100 RW467 River Rother at Killamarsh River Rother 100 RW476 River Hipper at Central Chesterfield River Hipper 25 RW477 Holme Brook at Ashgate Holme Brook 25 RW478 River Whitting at Old Whittington River Whitting 100 RW479 River Drone at Dronfield and River Drone 100 River Doe Lea at Bolsover Coking RW480 River Doe Lea 5 Works 034 FVF ER1 River Erewash at Pinxton River Erewash 5 Telemetered river gauging sites are linked to the fluvial flood warning service. Information gathered from these gauges informs the flood warnings issued via Floodline Warnings Direct (FWD) to emergency services, Parish Councils, businesses and households in flood-prone locations.

The areas at risk are identified by the Environment Agency’s Flood Zone maps, current flood warning areas can be seen on the EA Figures in Appendix D.

3.8 Other related plans and strategies The LPA’s policies, proposals and development sites within the DPD should aim to be consistent with a range of other related plans and strategies. Further details will be contained on the LPA’s Sustainability Appraisal Scoping Report. In terms of flood risk, the key additional plans that should be considered are: 3.8.1 Catchment Flood Management Plans Catchment Flood Management Plans (CFMPs) are high-level strategic planning tools through which the Environment Agency works with other key decision-makers within a river catchment to identify and agree policies for sustainable flood risk management. Ultimately all areas within England and Wales will have a long-term flood risk management policy. The Environment Agency is preparing CFMPs for all river catchments within England. These set out the broad level of flood risk posed to development, communities and assets and also apply a broad scale policy for managing this risk in each catchment in the short, medium and long term. CFMP for Don Valley (neighbouring council) has been published.

The EA stated there is no CFMP covering the CBC, BDC and NEDDC currently available.

3.8.2 River Basin Management Plans The Water Framework Directive requires the production of River Basin Management Plans (RBMPs) across the UK. These plans require assessment under the Strategic Environmental Assessment Directive (2001/42/EC) to identify wider effects on the environment.

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The Environment Agency is also responsible for preparation of RBMPs in accordance with the Water Framework Directive. These documents are a critical source of information for spatial planners considering the flood risk implications of new development.

The EA stated there is no RBMP covering the CBC, BDC and NEDDC currently available.

3.8.3 Strategic Flood Risk Assessments (SFRAs) A SFRA for the neighbouring council of is currently being undertaken and could become a planning consideration for future developments. The Peak District National Park Authority is also commissioning a SFRA jointly with District Council and High Peak Borough Council . 3.9 Data collection for other sources of flood risk Different bodies were contacted for information on other sources of flood risk: 3.9.1 Groundwater Flooding The Environment Agency does not have any records of historical flooding from ground water. However, they were able to provide a plan showing an outcrop of magnesium limestone in the area, which can be susceptible to groundwater flooding. This plan can be found in Figure 6. 3.9.2 Land Drainage This information was obtained from engineers from within Chesterfield Borough Council, Bolsover District Council and North East Derbyshire District Council. 3.9.3 Sewerage Severn Trent Water and Yorkshire Water were contacted for information on historical flooding from sewers. Both water companies maintain a register of locations that have experienced sewer flooding, called a DG5 register. Severn Trent Water is responsible for sewerage of parts of North East Derbyshire and Bolsover within the study area with Yorkshire Water responsible for Chesterfield, and parts of North East Derbyshire and Bolsover. Severn Trent is responsible for water supply only. It should be noted that water companies carry out a programme of upgrades based on their DG5 register and, as such, properties currently on the register may already be subject to mitigation works, which would alleviate the flooding problems. Severn Trent Water and Yorkshire Water have provided relevant extracts from their DG5 register for the Chesterfield, Bolsover and North East Derbyshire. 3.9.4 Canals British Waterways (BW) were contacted for information on flood risk from canals. BW stated that they do not own or maintain any of the canals in Derbyshire and they have no records relating to Chesterfield Canal. The Derbyshire County Council were contacted for information on Chesterfield Canal and other water bodies. The Canal is owned by the Derbyshire County Council and is maintained and protected by the Chesterfield Canal Partnership. The Chesterfield Canal Trust is a founder member of the Chesterfield Canal Partnership. This is made up of:

 Derbyshire County Council,  Chesterfield Borough Council,  North East Derbyshire District Council,  Rotherham Metropolitan Borough Council,  Council,  Nottinghamshire County Council,  British Waterways,  statutory and non-statutory bodies,  the voluntary sector and private enterprise. There is a short and unconnected stretch of the former Canal at Pinxton within Bolsover District. There is a mix of Derbyshire County Council (DCC), British Waterways, private landowners, wildlife trusts and British Coal who are the landowners throughout the length of the canal from Cromford to , and up the arm to Pinxton. DCC have

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managed the canal since the mid 1970's. Since then, there has been only one overtopping incident which was in 1989 at a point approximately two miles south of Cromford. Fortunately this did not result in a breach of the canal, but a breach did occur here in the 1920s. Derbyshire County Council gave a general description for the flooding history of the Chesterfield Canal. The Chesterfield Canal Trust has restored a section between Chesterfield and Staveley. The restored Chesterfield Canal commences at St Helena’s Weir in Chesterfield (immediately north of the Arnold Laver site). A weir and secondary overflow weirs regulate the water depth here. A single flood gate adjacent to St Helena’s Bridge controls entry to the canal. This flood gate is normally kept closed and water is admitted to the canal via a penstock and culvert with a controlling water regulator. The gate opens into the water flow so it is forced shut by floodwater and thus cannot be opened under flood conditions. The Canal then follows the eastern edge of the River Rother flood plain for the rest of its journey to Staveley. It accommodates the fall of the river valley floor by means of five locks. These are located at Tapton, Wheeldon Mill (Brimington), Bluebank, Dixons and . At no point is the canal more than 2 to 3 m above the river level and there is no settlement between the canal and the river. The River Rother water abstracted at Chesterfield is returned to the River Rother via a side weir at Staveley. An additional storm flow weir can be found at Tapton (discharging to the Tinker Sick and thence to the Rother). The canal has no history of flooding. During the major flood events of 2007 the canal did take exceptional volumes of water. Some did come via the flood gate at St Helena’s which was overtopped for a very brief period, however, the vast majority came directly from rainfall and from surface water (overland) flow into the canal channel. During the period the by weirs of the canal performed well taking excess water around the looks as they are designed to. No damage was recorded to the lock structures although some of the by weir channels suffered scour and bank undercutting and required remedial work. At no point did the canal overtop and create flooding in the surrounding areas. Since restoration commenced in the 1990 there was only one breach on the canal – at Tinker Sick in November 2007. This was caused by partial failure of a culvert which was already on the “to be replaced list”. The water discharged into the Tinker Sick brook and no damage was done to landscape or property. The majority of the canal between Chesterfield and Staveley has been rebuilt since 1998 and is well maintained. The LPAs were contacted for information on other sources of flood risk. This information is summarised in Chapter 5. 3.10 Data deficiencies A register of all the data collected can be found in Appendix C. The database provides information of where the data has come from, type of data, date and the owner of the data. Some information is also provided on the quality and relevance of the data. The SFRA aims to use the best available data to undertake a strategic assessment of levels and extents of flood risk. Some locations in the UK have more detailed and extensive data than has been produced in the past. Below is a summary of the major pieces of information on flooding which are missing from the study area and recommendations of future work that could be undertaken to address some data deficiencies. 3.10.1 Catchment Flood Management Plan (CFMP) A CFMP was requested from the EA but it was confirmed that there are non currently available for the study area. The EA are producing CFMPs for the whole country and this information should be reviewed when it becomes available. 3.10.2 River Basin Management Plan Again, this was requested from the EA but not provided as part of the study. Once this information becomes available it should be assessed to see if there are any likely impacts on development along the river corridors.

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3.10.3 Hydraulic Models The existing models provided by the EA cover the majority of the main rivers in the catchment; River Rother, River Hipper, River Whitting, River Doe Lea. In addition, they also provide flood levels for some minor watercourses such as sections of the River Drone, Pools Brook, Riddings Brook, Holme Brook and Barlow Brook. All the major watercourses in Chesterfield are covered by hydraulic models with the exception of the reach of the River Rother downstream of Works Road and the reach of the River Drone upstream of The Brushes. Also, there are several minor watercourse and land drains such as Trough Brook and sections of Barlow Brook and Riddings Brook where no flood level data exists. In Bolsover, the only available model data covers the River Doe Lea and an un-named tributary north of Shuttlewood. The only available model data for North East Derbyshire includes the section of the River Hipper through . The following areas have proposed developments but little or no hydraulic modelling information:

 Chesterfield – Most areas covered  Bolsover – Clowne  North East Derbyshire – Dronfield and Unstone, Eckington, Renishaw and Killamarsh Hydraulic modelling will be required for these areas to confirm flood levels and required finished floor levels. 3.10.4 Reservoirs and Canals PPS25 requires an assessment of flood risk from all sources. Many potential developments will have to assess flood risk for un-modelled artificial sources such as reservoirs and canals. Detailed reservoir Flood Risk Assessments may be a requirement in the near future. These assessments will help assess flood risk to potential developments downstream of reservoirs. A detailed reservoir assessment may be required if any of the following statements are true: 3  Reservoir is just below 25,000m threshold and, as such, is not covered by the Reservoir Act (1975)  Proposed development downstream of the reservoir is sufficient to increase the class of reservoir (i.e. would put more people at risk than the current design allows);  Unknown or riparian owner unlikely to maintain to required standards;  Evidence of potential structural failure or instability. 3.10.5 Additional Information Where other agencies have not provided data, they will continue to be consulted as a statutory consultee in the LDF process. These agencies will have the opportunity to bring forward additional data in due course. This information could be used to inform future updates of this SFRA.

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Figure 6: Groundwater Vulnerability Plan

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Causes of flooding

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4 Causes of flooding

High river levels are generally the result of prolonged rainfall. In the summer months the ground may be baked hard by the sun resulting in very high runoff and flash flooding during thunderstorms. In winter the soil conditions are wetter and temperatures lower and a greater proportion of the rainfall will find its way to the river. Recent wetter summers have similarly resulted in wetter ground and greater runoff.

The main source of flooding in the CBC, BDC, and NEDDC SFRA area is fluvial. The reason for this flood risk to people and property is a combination of insufficient channel capacity and the fact that the affected properties are generally on low lying land in the rivers natural floodplain.

Groundwater flooding can be caused by three main contributing factors; prolonged rainfall, higher than average groundwater levels and outcrops of aquifers (in the form of springs). Flooding can also occur due to failure of infrastructure such as flood defence assets, culverts, sewers, reservoirs and canals. Flood risk locations for areas outside of the Flood Zone maps have been put into a GIS database. The flood risk locations can be seen in the drawings in Appendix D. Each location has been given a reference number. The table in Appendix A provides more details on the type of flood risk at this location. The other flood risk locations include flooding from sewers, reservoirs, canals, land drainage and ordinary watercourses. 4.1 Overflowing of watercourses (including Breach) When the flow in a river or stream exceeds the capacity of the channel to convey that flow, either because of limited cross-sectional area, limited fall, or a restricted outfall, then the water level in that channel will rise until the point is reached where the banks of the channel are overtopped. Water will then spill over the channel banks and onto the adjoining land. With an upland river the adjoining land is its natural flood plain. This will be fairly well defined and generally be of limited extent. Floodplains are characterised by flat, riparian land along the valley floor. In pre-industrial England, such land was regarded as liable to flooding and was traditionally reserved for grazing and stock rearing and human settlements were almost always established beyond the edge of the floodplain. In the industrial age and more recent times with different priorities, pressures for development have resulted in the widespread colonisation of floodplains, often with steps taken to mitigate the associated risks of flooding. When overtopping of an embanked watercourse occurs, the depth of water flowing over the floodwall or embankment will probably be small, a few centimetres at most. The bank will act like a weir and the rate of flow per unit length will be relatively modest and this, combined with the limited duration of the overtopping, will limit the volume of water cascading over the defences to cause flooding. If overtopping does occur and the protected area is of considerable extent, any resulting flooding will often be disruptive rather than be disastrous. The situation becomes far more critical if overtopping of an earth embankment erodes its crest, leading to a breach in the embankment.

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4.1.1 Development in undefended areas

Where development is proposed in undefended areas of floodplain, which lie outside of the functional floodplain, the implications of ground raising operations for flood risk elsewhere need to be carefully considered and appropriate guidance provided to developers within the SFRA. There are few circumstances where provision of compensatory flood storage or conveyance will not be required for undefended fluvial floodplain areas. This is because, whilst single developments may have a minimal impact, the cumulative impact of many such developments can be significant. More information for individual potential development sites can be found in the flood risk matrix.

4.1.2 Development behind defences

When proposing new development behind flood defences, the impact on residual flood risk (see glossary) to other properties should be considered.

New development behind flood defences can increase the residual flood risk, should these defences breach or overtop, by disrupting conveyance routes (flow paths) and/or by displacing flood water. If conveyance routes that allow flood water to pass back into a river following failure of a flood defence are blocked, this will potentially increase flood risk to existing properties. If there is a finite volume of water able to pass into a defended area following a failure of the defences, then a new development, by displacing some of the flood water, will increase the risk to existing properties. Policy and practice for managing these risks as part of the spatial planning process has been included in the SFRA.

It is recommended that, should any potential development sites be proposed in a defended flood area, the potential cumulative impact of loss of storage at the potential development sites on flood risk elsewhere within the flood cell (area constrained by boundaries that would fill before overtopping into another flood cell) should be considered.

Such assessment should be appropriate to the scale and nature of the proposed development and flood risk. If the potential impact is unacceptable, mitigation should be provided. 4.2 Breaching of Embankments An earth embankment may be breached as a direct result of overflowing. Overtopping of a bank, especially when concentrated over a short length of bank, results in a rapid flow of water down the rear slope of the bank. This can cause erosion, which starts at the rear of the bank and works its way forward towards the channel. As the crest of the bank is washed away the flow through the small initial gap increases and a small breach is created. This becomes steadily bigger as water flows through it, eroding the sides and base of the breach, and a rapid and progressive failure of the embankment follows. Complete collapse of the bank may take only minutes. The contents of the embanked channel then pour through the breach and across the surrounding land. A tarmac road or dwarf floodwall along the crest of a floodbank may inhibit the rate of initial erosion and postpone or even prevent the creation of a breach, depending upon the duration of overtopping. Experience, fortunately limited, shows that when a fluvial floodbank breaches, even if not by overtopping, it does so near the peak of the flood when the flow in the river and hence flood levels are at or near their maxima. Experience also suggests that breaches in river embankments usually extend from 20 to 30 metres in length and rarely grow to more than forty metres. The design of a floodbank (or floodwall) incorporates a certain level of freeboard to allow for uncertainties, bank settlement, wave action, etc. but the height of any floodbank is determined primarily by the peak height of the design flood. Because of freeboard, the return period of the flood which gives rise to overtopping must be greater than that of the design flood. The return period of flooding from a breach caused by overtopping will be essentially the same as for the far less severe flooding resulting from that overtopping alone, but it must be borne in mind that

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breaches in earth embankments can occur from causes other than overtopping and may thus have return periods significantly less than that for which the embanked channel was designed. Apart from overtopping, breaches in floodbanks can occur where weak spots in the bank have been created over a long period by gradual leakage through the bank at old, forgotten structures buried in the bank such as culverts or sluices (“slackers”), or where the activities of burrowing animals such as rabbits or rodents have impaired the integrity of a floodbank. These inherent weaknesses may not be readily apparent under normal conditions but when an exceptional level of pressure through the bank arises during flood conditions, a failure may occur, quickly giving rise to a breach. This may well happen in a flood of considerably lesser magnitude and return period than the design flood. Furthermore, since the inherent weakness tends to increase slowly with age, the fact that a bank did not fail in an earlier flood does not guarantee that it will not fail in a comparable (or even a lesser) flood at some time in the future. If, however, a floodbank is of recent construction it may be assumed that it has been properly engineered and, provided that there is an adequate inspection and maintenance regime, the risk of breaching as a result of the factors outlined above is negligible. 4.3 Mechanical, Structural or Operational Failure

Although less common than overtopping or breaching of defences, flooding can also be caused by the mechanical or structural failure of engineering installations such as land drainage pumps (or their power supplies), sluice gates (or the mechanism for raising or lowering them), lock gates, outfall flap valves etc.

Such failures are, by their nature, more random and thus unpredictable than the failures described in the previous sub-sections, and may occur as a result of any number of reasons. These include poor design, faulty manufacture, inadequate maintenance, improper operation, unforeseen accident, vandalism or sabotage.

Structural failure, in this context, is also taken to include the failure of "hard" defences in urban areas such as concrete floodwalls.

"Hard" defences are the most unlikely to fail by the overtopping / erosion / breaching sequence experienced by earth embankments. Their failure tends to be associated with the slow deterioration of structural components, such as rusting of steel sheet piling and concrete reinforcement, or the failure of ground anchors. Such deterioration is often difficult to detect and failure, when it occurs, may well be sudden and unforeseen. Structural failure of "hard" defences is most likely to happen at times of maximum stress, when water levels are at their highest during a flood. Failure of hydraulic structures and "hard" defences can, under certain circumstances, be precipitated by the scouring of material from beneath their foundations by local high velocity flows or turbulence, especially under flood conditions.

Flooding can also be caused or exacerbated by the untimely or inappropriate manual operation of sluices, or by the failure of the person or organisation responsible to open or close a sluice at a critical time.

Responsibility for the operation of sluices rests with various public bodies as well as riparian landowners. Operational failures of this nature generally occur during a flood event and their results are to exacerbate rather than to cause flooding, and their impact is normally limited in extent.

Flooding especially that caused by overflowing of watercourses, can be exacerbated by other operational failures. These failures can also include neglected or inadequate maintenance of watercourses resulting in a reduction of their hydraulic capacity. Flooding can also be caused or exacerbated by bridge or culvert blockages, although these are not necessarily due to maintenance failures and may be caused by debris, natural or manmade, swept along by flood flows.

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The risks associated with this category of failures are almost impossible to quantify, especially as experience has shown that there is a joint probability relationship between this class of failure and flooding resulting directly from extreme meteorological events. It can of course be argued that if a risk of this type was quantifiable and found to be finite then action should already have been taken to alleviate the risk. Even an assessment of relative risk for failures of this type must depend on a current and detailed knowledge of the age and condition of plant, its state of maintenance, operating regime etc at a significant number of disparate installations.

More information on the potential flood risk from mechanical, structural or operational failure of assets within the study area can be seen in Section 6.5.

4.4 Flooding from reservoirs, canals and Other Artificial Sources

Flooding from artificial sources occurs from a facility being overwhelmed and/or as a result of dam or bank failure.

Non-natural or artificial sources of flooding can include reservoirs, canals and lakes where water is retained above natural ground level, operational and redundant industrial processes including mining, quarrying and sand and gravel extraction, as they may increase floodwater depths and velocities in adjacent areas. The potential effects of flood risk management infrastructure and other structures also need to be considered. Reservoir or canal flooding may occur as a result of the facility being overwhelmed and/or as a result of dam or bank failure. The latter can happen suddenly resulting in rapidly flowing, deep water that can cause significant threat to life and major property damage. Industrial flooding can also occur when pumping ceases and groundwater returns to its natural level, for example in former mineral workings and urban areas where industrial water abstraction is reduced from its former rate. Some of this flooding may be contaminated. 4.5 Groundwater Flooding

Groundwater flooding occurs as a result of water rising up from the underlying rocks or from water flowing from springs. Flooding can be both at higher levels (from springs up a scarp slope) or at lower levels e.g. locations of former village ponds etc.

Groundwater flooding tends to occur after much longer periods of sustained high rainfall. Higher rainfall means more water will infiltrate into the ground and cause the water table to rise above normal levels. Groundwater tends to flow from areas where the ground level is high, to areas where the ground level is low. In low-lying areas the water table is usually at shallower depths anyway, but during very wet periods, with all the additional groundwater flowing towards these areas, the water table can rise up to the surface causing groundwater flooding. Groundwater flooding is most likely to occur in low-lying areas underlain by permeable rocks (aquifers). These may be extensive, regional aquifers, such as Chalk or sandstone, or may be localised sands or river gravels in valley bottoms underlain by less permeable rocks. Groundwater flooding takes longer to dissipate because groundwater moves much more slowly than surface water and will take time to flow away underground. 4.6 Land drainage, sewer and ordinary watercourse flooding

Almost all localised flooding of a serious nature occurs as a result of an exceptionally severe rainfall event, localised in extent and duration and generally during the summer.

This flooding can, however, be exacerbated by two factors, blockages in the local surface water drainage system or by "floodlocking". Each of these factors is considered separately below. In some instances, in what would otherwise have been a relatively moderate rainstorm, these factors can themselves be the cause of flooding.

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Intense storm rainfall, particularly in urban areas, can create runoff conditions which temporarily overwhelm the capacity of the local sewer and drainage system to cope with the sudden deluge. Localised “flash” flooding then occurs.

In upland areas with small, relatively steep, impermeable catchments, this may result in quite severe flooding over a limited area, often with a considerable depth and velocity of flood water. The duration of such flooding is usually relatively short but this does not mitigate its impact for those affected, especially when the flooding may have developed suddenly and unexpectedly. In addition localised urban flooding can occur where the surface water drainage system is overwhelmed and pumps are not sufficient for an extended period of localised heavy rain. In its natural state, if the channel capacity of a stream is exceeded the channel will overflow along a considerable length and the resultant flooding is distributed over a wide area. If, however, the stream runs through a long culvert and the hydraulic capacity of that culvert is exceeded under flood conditions the culvert becomes surcharged at its upstream end. Water levels will then rise rapidly and localised flooding upstream of the culvert, often quite serious, can occur. The flood water, in attempting to follow the natural line of the culverted watercourse, may also flow through the built-up area above the line of the culvert. This applies equally to many larger surface water sewerage systems in urban areas which are, in effect, culverted watercourses. 4.6.1 Blockages in local surface water drainage

Local flooding is often exacerbated by deficiencies in the local surface water drainage system, but these can usually be remedied by relatively minor works once they have been exposed by a flooding event. Local flooding can also be caused by temporary blockages or obstructions in a drainage system, especially one that has been extensively culverted.

Such flooding can therefore be virtually random in its occurrence, although the prevalence of blockages at a particular location would suggest a systematic problem, justifying action to modify the drainage system at that location in order to resolve it. 4.6.2 Flood-locking

In inland areas, all local surface water drainage systems discharge to a major stream or river. This discharge is by gravity, except where pumps have been installed. If the receiving stream or river is in flood, especially where that watercourse is contained within raised floodwalls or banks, the flow in the local drainage system can no longer drain to the river and is impounded behind the defence line for the duration of the flood. This is known as "floodlocking". This can result in secondary flooding within the defended area, even though the defences may not have been breached or overtopped. Fortunately, this secondary flooding is almost always much less severe or widespread than primary flooding from the main river would have been.

The occurrence of secondary flooding depends on the coincidence of heavy rain over the local drainage catchment with "flood-locking" of its outfall. In most instances, the rainfall event that caused the flood conditions in the river may also have caused high flows in the local drainage system but because of the much slower hydrological response of the river, the rapid runoff from the local catchment may have discharged to the river before the flood peak in the river arrives at the local drainage outfall. Because secondary flooding depends upon what are either random events or a complex coincidence of events, its probability of occurrence is difficult to quantify and it falls within the category of "residual risk".

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4.6.3 Land drainage and sewer flooding

The Environment Agency promotes the use of sustainable drainage systems (SuDS) within urban areas.

Drainage systems can be developed in line with the ideals of sustainable development, by balancing the different issues that should be influencing the design. Surface water drainage methods that take account of quantity, quality and amenity issues are collectively referred to as Sustainable Drainage Systems (SuDS). These systems are more sustainable than conventional drainage methods because they:

 Manage runoff flow rates, reducing the impact of urbanisation on flooding.  Protect or enhance water quality.  Are sympathetic to the environmental setting and the needs of the local community.  Encourage natural groundwater recharge (where appropriate). This is achieved by:

 Dealing with runoff close to where the rain falls.  Managing potential pollution at its source now and in the future.  Protecting water resources from point pollution (such as accidental spills) and diffuse sources. Surface water drainage in the catchment is covered by a variety of different bodies. Severn Trent Water and Yorkshire Water have responsibility for adopted surface water sewers. Drains that exist in association with highways and private surface watercourses could be the responsibility of the LPAs, Highways Agency or private landowners. The adoption of SuDS for maintenance purposes is still under debate and can be a barrier in seeing them implemented for new developments. More details on the use of SuDS and adoption of SuDS can be found in section 9.3. Sewers serving a development will either be a combined system or made up of separate foul and surface water sewers. Sewer flooding occurs more commonly in locations that have a combined system. Adopted sewers are designed for a 2 year no surcharge and 30 years no flooding. Areas with separate sewers are less likely to exceed their capacity. However both sewer systems are at a similar risk of flooding as a result of blockages and failed pumping stations. 4.7 Catchment characteristics The main rivers that drain the catchment areas are the River Rother, River Hipper, River Whitting, River Drone, River Doe Lea, River Moss and . The Rivers Amber and Erewash drain to the south. A small part of Bolsover District is drained by the . In addition, there are numerous other watercourses such as Holme Brook, Pools Brook, Barlow Brook, Riddings Brook, Lough Brook, Sud Brook, Linacre Brook, Tricket Brook, and Smithy Brook. 4.7.1 River Rother The River Rother rises near Pilsley, 7 miles south-east of Chesterfield. The river flows north through a mixed catchment containing rural areas, villages, the town of Clay Cross and industrial areas. The river flows under a railway adjacent to a large disused chemical works (Avenue Coking Plant). Downstream of this point, the Rother passes through a flat-bottomed valley, where the river is surrounded by a marshy floodplain area with reeds, before entering the town of Chesterfield. The river passes mainly through the industrial areas on the eastern side of Chesterfield, and is open all the way through the town, apart from road and railway crossings. In the south of the town, an unnamed watercourse at Storforth Lane discharges to the River Rother. Nearer to central Chesterfield, Spital Brook connects to the Rother adjacent to the A61 bypass at . The Rother is joined by the River Hipper on the left bank, and north of the town the river is joined by the River Whitting, also from the left bank. Downstream of Chesterfield, the River Rother follows the railway to the north-east. There is a gauging station at Whittington, not far below the confluence with the River Whitting, beside a

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large sewage works. For the next three miles the river is surrounded by large-scale industrial works, with the urban areas of Brimington and Staveley to the south and east, and a rural hilly catchment to the north. At Renishaw, the Rother is joined from the right bank by the River Doe Lea. At Eckington, enters the Rother from the west. 4.7.2 River Hipper and Holme Brook The River Hipper flows from uplands in the west in an easterly direction into the centre of Chesterfield, passing to the south of Holymoorside and splitting Brookside and Brampton in the north and Walton and to the south. In the centre of the town it meets the River Rother which is in turn a tributary of the River Don. The main tributary of the Hipper is Holme Brook. Holme Brook is a continuation of Linacre Brook, which is supplied by three large reservoirs; Upper, Middle and Lower Linacre Reservoir, supplying water to Severn Trent Water. Downstream, Holme Brook flows to the north of Ashgate before joining the Hipper at Queens Park, to the south west of the town centre. Both the Hipper and Holme Brook flow down steep-sided mainly rural valleys before joining in the Brampton district of Chesterfield. The catchment is predominantly underlain with impermeable rocks of lower and middle coal measures with small area of Millstone Grit in the upper catchment. Soils in these areas are well drained. Considerable parts of the lower catchment are formally drained by a network of sewers. There have been frequent floods at the confluence of the Rother and the Hipper The standard average annual rainfall (1961-1990) for the catchment is estimated as 874mm, which is typical for the eastern slopes of the Pennines. 4.7.3 Rivers Whitting, Drone, Barlow Brook and Riddings Brook The River Whitting is the name given to a short stretch of river linking the confluence of the River Drone and the Barlow Brook to the River Rother. It originates in the high ground to the northwest of Chesterfield. The River Whitting joins the River Rother at a location immediately north of Brimington Road North in Chesterfield. The River Drone rises in the Batemoor district on the southern extremity of . It flows through Dronfield in a steep channel and joins the River Whitting to the east of Sheepbridge Lane in Sheepbridge. The upper part of the catchment is largely urban, and below Dronfield the catchment is largely rural. The Drone catchment is predominantly permeable and, as such, the effects of urbanisation would be more significant. This is also the case for Barlow Brook. Riddings Brook is a small watercourse. It originates to the west of Dunston Housing Estate in Chesterfield and follows a steep and largely culverted route along the northern boundary of Chesterfield and discharges into the River Whitting near Armytage Industrial Estate. 4.7.4 River Doe Lea, Hawke Brook and Pools Brook The River Doe Lea rises to the northeast of and flows north, parallel to the upper Rother, through a gently-sloping valley to the east of Chesterfield. On the either side of the river, the land rises up to an altitude of 180 mAOD. Near Staveley, the Doe Lea is joined by the Hawke Brook from the east and the Pools Brook from the west. 4.7.5 River Poulter A minor watercourse, known as the River Poulter rises near Upper Langwith, and flows eastwards through Langwith into the main River Poulter that runs outside of the district boundary. 4.8 Flood Protection of the catchment 4.8.1 River Rother The main flood alleviation measures on the River Rother are controlled washlands downstream of the study area designed to reduce flood risk in Rotherham and Doncaster. There is also a controlled washland on the Rother by Slitting Mill Farm, just upstream of the River Doe Lea confluence. Elsewhere there are areas of uncontrolled washlands, i.e. natural floodplains, for example a marshy area just south of Chesterfield, and an area of grassland in the St Augustines area of Chesterfield. Houses adjacent to this area on Sherwood Street and Hawthorne Street have suffered flooding, but are protected to some extent, by flood defences for an estimated 1 in 50 year flood event.

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4.8.2 River Whitting The flood risk along the River Whitting has been reduced as a result of a flood alleviation scheme carried out in the mid 1980. This scheme was designed for an estimated 1 in 50 year flood event, although the Station Road Bridge is recognised to fall short of this standard. 4.8.3 River Drone A flood storage reservoir has been constructed upstream of Dronfield on the River Drone. This, together with some low walls and embankments in the town, is designed to provide a 75-year standard of flood protection along the River Drone. The previous standard of protection in central Dronfield was only 5 years. 4.8.4 River Doe Lea On the River Doe Lea there are significant areas of natural floodplain that allow flood peaks to attenuate. There are a number of designated washlands between and Markham Vale development.

Flooding in Chesterfield, Bolsover and North East Derbyshire

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5 Flooding in Chesterfield, Bolsover and North East Derbyshire

Locations at risk of flooding have been identified through the Environment Agency’s Flood Zone maps and historical flooding records, information from each of the LPAs, Derbyshire County Council, and Severn Trent Water. A register of flood risk locations has been created from the data collection stage. Details of each location can be found in Appendix A. A reference number on the register relates to the following drawing in Appendix D: Drawing Name Drawing Number Historic Flooding, Flood Storage and Defences –Chesterfield Overview 55328/C/HF/O Historic Flooding, Flood Storage and Defences – Chesterfield Area 01 55328/C/HF/01 Historic Flooding, Flood Storage and Defences – Chesterfield Area 02 55328/C/HF/02 Historic Flooding, Flood Storage and Defences – Chesterfield Area 03 55328/C/HF/03 Historic Flooding, Flood Storage and Defences – Bolsover Overview 55328/B/HF/O Historic Flooding, Flood Storage and Defences – Bolsover Area 01 55328/B/HF/01 Historic Flooding, Flood Storage and Defences – Bolsover Area 02 55328/B/HF/02 Historic Flooding, Flood Storage and Defences –Bolsover Area 03 55328/B/HF/03 Historic Flooding, Flood Storage and Defences – Bolsover Area 04 55328/B/HF/04 Historic Flooding, Flood Storage and Defences – Bolsover Area 05 55328/B/HF/05 Historic Flooding, Flood Storage and Defences – Bolsover Area 06 55328/B/HF/06 Historic Flooding, Flood Storage and Defences - Bolsover Area 07 55328/B/HF/07 Historic Flooding, Flood Storage and Defences – Bolsover Area 08 55328/B/HF/08 Historic Flooding, Flood Storage and Defences – Bolsover Area 09 55328/B/HF/09 Historic Flooding, Flood Storage and Defences - Bolsover Area 10 55328/B/HF/10 Historic Flooding, Flood Storage and Defences – North East Derbyshire Overview 55328/B/NE/O Historic Flooding, Flood Storage and Defences – 55328/NE/HF/01 North East Derbyshire Area 01 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/02 North East Derbyshire Area 02 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/03 North East Derbyshire Area 03 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/04 North East Derbyshire Area 04 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/05 North East Derbyshire Area 05 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/06 North East Derbyshire Area 06 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/07 North East Derbyshire Area 07 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/08 North East Derbyshire Area 08

These locations have been used to add evidence to the initial Sequential Test undertaken for the potential future development sites (Appendix B). 5.1 Main River Flooding in Chesterfield There are a number of watercourses in the Chesterfield area as follows:

 River Rother  River Hipper  River Drone  River Whitting  River Doe Lea  Pools Brook  Barlow Brook  Sud Brook  Riddings Brook  Trough Brook

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 Linacre Brook  Holme Brook  Bridholme Brook  Spital Brook  Tinker Sick  A number of un-named watercourses

Flood Zones have been produced for parts or all of these watercourses, however only detailed modelling exists for the River Hipper, River Whitting, Holme Brook, part of River Rother, the unnamed watercourse around Storforth Lane, Pools Brook, part of River Doe Lea, and Hawke Brook. See Drawing No. 55328/C/F/01 in Appendix D for details of the Flood Zones. In addition to the Flood Zones and data from the hydraulic models, local knowledge holders have been consulted and the EA’s archived flood records sourced to supplement the risk shown on the Flood Zone maps and to identify other areas at risk from various sources of flooding.

Site specific FRAs may be required to provide more detail where the proposed development is within a broad-scale flood outline.

River Rother has been identified as the watercourse that poses the greatest flood risk in Chesterfield.

5.2 Analysis of problem areas in Chesterfield 5.2.1 South Chesterfield - Unnamed watercourse south of Storforth Lane Several houses off Storforth Lane, Hartfield Close and Ingleton Road are shown to be at risk from the 1 in 100 year fluvial storm based on the hydraulic model, although are not designated as Flood Zone 3 on the EA’s Flood Zone maps and there is no history of flooding at this location. Flooding is most likely to occur due to a blockage of the culvert which carries the watercourse under the railway and into the River Rother. Water would tend to pond upstream of Ingleton Road. Although there is no history of flooding at this location, the possibility should still be considered when proposing any development in this area. Flood levels, taken from the hydraulic model, should be obtained by the developer. 5.2.2 South Chesterfield - River Rother and River Hipper There is a large area of washland (or designated flood storage area) stretching from the east of Birdholme Farm to the east of St Augustine’s School, by Turnoaks Industrial Estate (see ID CHE225). This area floods frequently and it is important that this process is allowed to continue as not to increase flooding problems downstream. In extreme floods the water could rise high enough to inundate the bowling complex off Storforth Lane, the church hall at the junction of Derby Road and Jawbones Hill and several houses on Heulagh Way, Herriot Drive and St Giles Close. On the left bank, there are many properties at risk on Bridge Street, Hawthorne Street, Sherwood Street and Rother Vale Road (see CHE225, CHE116 and CHE117). These are protected by an embankment and sheet piling of 30 year design standard, but these would be overtopped in severe events. Downstream of here there is a significant area at risk from fluvial flooding at the confluence of Spital Brook and the River Rother (see CHE224, CHE209). The area at risk spans from the works on Baden Powell Road in the west to Saint Leonards Drive in the east and from Redvers Buller Road in the south to Hady Hill in the north, in addition to further areas on either side of the watercourses. This area could flood from the Rother or, if banks collapsed, from the Hipper. Floodwater from the Rother may enter this area from the west; by flowing along Road under the railway bridge. It should be noted that parts of this area are within the 5-year flood outline as predicted by the hydraulic models, based on a feasibility study carried out in 1988. Shops on the Ravenside Retail Park are at risk of flooding from the River Hipper (see CHE211). There is an electricity substation at risk beside the river. Several other properties on Hipper

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Street South are in the modelled flood outline. Queens Park and the area around the confluence of the Hipper and Holme Brook are also at risk of flooding. 5.2.3 West Chesterfield - River Hipper. Where the Hipper enters the Chesterfield Borough there are several properties along Yew Tree Drive shown to be at risk from the 100 year fluvial flood according the the EA’s Flood Zone maps. There is a further area along Somersall Lane which, although not located in Flood Zone 3 on the EA’s Flood Zone maps, is predicted to be at risk from the 1 in 100 year fluvial flood based on the hydraulic models, and has also flooded historically (see CHE223). Flooding in this location may be due to insufficient capacity of Somersall Lane culvert. Downstream of Somersall Lane, properties on Oakfield Avenue and Haddon Close are shown to be at risk from the 100 year flood based on the EA’s maps but are not within the 100 year modelled flood extents. Historical flooding has occurred at this location (CHE10, CHE15, CHE16 and CHE17). However, it does not appear to have affected any residential areas. In Walton, there is a small reservoir, Walton Dam, which appears to be located above the properties directly north. As such, this should be a major consideration for developers working within this area. Further downstream is the confluence with Holme Brook. Directly upstream of Holme Brook is another significant area of flood risk spanning from Factory Street in the west to Boythorpe Road in the east and from Wheatbridge Road (A619) in the north to Dock Walk in the south. This area is located in Flood Zone 3 on the EA’s Flood Zone maps, is within the 100 year modelled flood extents and has suffered from flooding historically in both August 2000 and June 2007 (CHE170). This area contains a mixture of residential, commercial and industrial properties. There are no flood defence structures located along this section of the Hipper. 5.2.4 Ashgate - Holme Brook. The only notable area of flood risk is located directly upstream of Ashgate Road culvert. Several houses on Ashgate Road and Ashgate Valley Road are at risk, potentially at risk due to the restriction of the culvert under the road and petrol station. In addition, residential properties on Chester Street. 5.2.5 East Chesterfield: area around station - River Rother. This area includes stables and fields by Rose Cottage and offices on the left bank upstream of Brimington Road bridge. Both are likely to be flooded frequently (CHE210). Upstream of the station, properties along Wain Avenue are also at risk. At lower risk, but still vulnerable to the 100-year flood, are the houses on Tapton Terrace and the road under the railway bridge (see ID CHE207, CHE206 and CHE166). Further downstream, the industrial area by the river, particularly on the right bank, is low-lying and at risk. It is understood that this area is designated for regeneration by Chesterfield Waterside. It is essential that the sequential approach is used to ensure this development is safe and does not increase flood risk elsewhere. All residential development at this location must be above the flood level with safe access to dry land. 5.2.6 Northwest Chesterfield – Barlow Brook, River Drone, River Whitting and Riddings Brook Several industrial and commercial properties upstream of the confluence with the River Drone on both sides of Barlow Brook are located in Flood Zone 3, however, there is no history of flooding at this location. Residential properties are at risk on Station Road from the Riddings Brook due to culvert restrictions. Also although not recently, Racecourse Road has flooded due to a blocked culvert in the past At the confluence with the River Drone (where Barlow Brook and the River Drone join to form the River Whitting) there is a large area which has flooded in the past (CHE220) possibly due to the restriction of the culverts under the A61 and railway embankment. This mainly affects a large industrial site east of Sheepbridge Lane. Downstream of the railway embankment, there is a large area which has suffered historical flooding (CHE217) stretching from the railway embankment to the confluence with the River Rother. There are raised man made defences located mainly along the right bank of the Whitting which seems to have offered some flood protection from the recent June 2007 floods, as only parts of this area were subject to flooding (including all of the Armytage Industrial

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Estate). However, the defences are only to a 50 year design standard and, as such, all this area remains potentially at risk from severe flooding. 5.2.7 North Chesterfield – River Rother and Tributaries At the confluence with the River Whitting there is a large area of washland located between the railway embankment and Chesterfield Canal. This area is subject to regular flooding, which mainly affects commercial and industrial properties. To the west of the railway and north of the sewerage works, the area around Ashcroft Drive and Burnbridge Road has been subjected to historical flooding from a tributary to the Rother (CHE1, CHE201, CHE205 and CHE208). This area is designated as Flood Zone 1 on the EA’s Flood Zone maps but would require a detailed flood risk assessment to be carried out to determine the risk and potential flood levels. Between the River Whitting and Hawthorn Hill there are large areas of washlands on both banks of the river. Areas affected are predominantly rural with a few industrial properties in Staveley, including Staveley Clock Tower Industrial estate on Works Road and the residential property of SlittingMill Farm. Flood defences offer protection to the farm from the 30 year flood. 5.2.8 Doe Lea catchment In the village of , there are a few houses by the playing field that may be at risk from the River Doe Lea in a 100-year event (see CHE186) although Erin Road forms an embankment between the river and the low-lying ground within the village. The grassy area south of Poolsbrook acts as a washland. The washland area continues downstream on the right bank along the playing fields. These areas are protected by an embankment of 30 year design standard, but this will be overtopped in severe events . Downstream of Poolsbrook the Doe Lea flows to the east of Staveley to the confluence with the River Rother and mainly affects rural areas. The only urban areas at risk include part of a school site at Netherthorpe and some residential properties, a sports ground and Riverdale Park on Bent Lane. 5.2.9 Areas of main concern The following areas are assessed as being at significant and/or frequent risk of flooding in Chesterfield:  The Derby Road (St Augustines) area of Chesterfield (River Rother)  The Rother-Hipper confluence (Rivers Rother and Hipper)  Tapton Terrace and the area near Chesterfield station (River Rother)  The industrial area including the Arnold Laver timber yard (River Rother)  The Station Road area of Whittington (River Whitting).  Staveley Works, Staveley (River Rother)  Chatsworth Road, area near Chesterfield (River Hipper)  Ravenside Retail Park, Chesterfield (River Hipper)  Horns Bridge Roundabout (A617), Chesterfield (River Rother) 5.3 Main River Flooding in Bolsover There are a number of watercourses in the Bolsover area as follows:

 River Doe Lea  River Meden  River Poulter  Stockley Brook  Milwood Brook  Westwood Brook  Morton Brook  Normanton Brook  River Erewash  Hawke Brook  A number of minor or un-named watercourses and land drains. Flood Zones have been produced for most of the watercourses running through the Bolsover area although the only detailed modelling available covers part of the River Doe Lea and Hawke Brook.

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River Doe Lea has been identified as the watercourse that poses the greatest flood risk in Bolsover.

5.4 Analysis of problem areas in Bolsover 5.4.1 River Doe Lea The only notable area of flood risk from the River Doe Lea is at the existing industrial works either side of Buttermilk Lane (see BDC76) at the confluence with two un-named land drains. Flooding may be due to inadequate capacity in the culvert under Buttermilk Lane. The area currently affected is low vulnerability industrial uses. However, this site is designated for redevelopment. Ideally, low vulnerability commercial, industrial, retail etc. development should be located here or the site should be sequentially tested to ensure any high vulnerability uses (such as residential) are located outside the flood extents. 5.4.2 South Bolsover – Normanton Brook Minor flooding occurs along the length of Normanton Brook (see BDC87, BDC89, BDC81 and BDC85) but this only affects rural areas and is not currently designated for development. 5.4.3 Southeast Bolsover – River Erewash Flooding affects properties on Beech Avenue, Alexandra Terrace or York Terrace, Pinxton and the southern parts of the Brookhill Industrial Estate. The references are (BDC 97 - 101). The area is identified as a Flood zone 2 and 3 on the Environment Agency Maps. There is no development currently proposed in the area 5.4.4 Southwest Bolsover – Westwood Brook and Morton Brook There is a small residential area to the north of Station Road which is located in Flood Zone 3 on the EA’s Flood Zone maps, although there are no records of historical flooding at this location. There is no development currently proposed in the area. 5.4.5 – River Meden The area between Chesterfield Road and the A617 is located in Flood Zone 3 on the EA’s Flood Zone maps and has also suffered historical flooding (see BDC28, BDC88 and BDC94). There is no development currently proposed in the area. 5.4.6 Shirebrook – Un-named Watercourse There is a small area at The Meadows north of Sookholme Road which is located in Flood Zone 3 on the EA’s Flood Zone maps, although there are no records of historical flooding at this location. This site is currently designated for redevelopment and the developer may be expected to carry out hydraulic modelling to determine flood levels and accurately assess the flood risk at this site. 5.4.7 Clowne – Un-named Watercourse An un-named watercourse flows southeast from Harlesthorpe Reservoir through the centre of Clowne and there are some minor areas on both banks designated as Flood Zone 2 or 3 with historical flooding problems (see BDC20, BDC21 and BDC22). There are multiple sites designated for redevelopment in this area and a detailed study may be required to accurately determine the flood risk. In addition to the watercourse, flood risk from the reservoir must also be taken into consideration. 5.4.8 Barlborough – Un-named Watercourse All of Barlborough is designated as Flood Zone 1 but an area around Shunters Drift has flooded due to a blockage of a culvert debris screen. There is no development currently proposed at this location. 5.4.9 Areas of main concern The following areas are assessed as being at significant and/or frequent risk of flooding in Bolsover:

 Alexander Terrace and York Terrace and the southern parts of the Brookhill Industrial Estate, Pinxton (River Erewash)  Creswell Road and Station Road at Clowne, (unnamed watercourse from Harlesthorpe Dam)  Pleasley Bridge, and factories and warehouses, Chesterfield Road, Pleasley.(River Meden)  Pleasley Vale Mills (River Meden)

Faber Maunsell Chesterfield, Bolsover and North East Derbyshire SFRA 67

5.5 Main River Flooding in North East Derbyshire There are a large number of watercourses in the North East Derbyshire area as follows:

 River Amber  River Rother  River Hipper  River Drone  Press Brook  Smithy Brook  Brook  Hodgelane Brook  Smalley Brook  Marsh Brook  Tricket Brook  Redleadmill Brook  Locko Brook  Muster Brook  Brook  Pools Brook  Birdholme Brook  Birley Brook  Linacre Brook  Crowhole Brook  Barlow Brook  Dunston Brook  Totley Brook  The Moss  A number of un-named watercourses Flood Zones have been produced for most of the watercourses running through the North East Derbyshire area although the only detailed modelling available covers part of the River Hipper and River Rother.

River Rother has been identified as the watercourse that poses the greatest flood risk in North East Derbyshire. Renishaw and Eckington are areas in NEDDC that have been identified as at risk of flooding from the River Rother.

5.6 Analysis of problem areas in North East Derbyshire 5.6.1 South of NE Derbyshire – River Amber, Smithy Brook and Alfreton Brook There are areas of Flood Zone 3 and historical flooding downstream of Ogston Reservoir (See NEDDC52) but these affect rural areas only and there are currently no development proposals at this location. Upstream of the confluence of River Amber and Alfreton Brook there are large areas, including part of the Amber Mill and Brook Farm (see NEDDC52 and NEDDC54) within 1 in 100 years flood outline. Part of the fields adjacent to Halls Plantation at Alfreton is protected by embankment in the right river bank of 1 in 100year standard of protection (see NEDDC54). 5.6.2 South of NE Derbyshire – Morton Brook There is an area of Flood Zone 2 and 3 at the confluence of Morton Brook and Westwood Brook, directly adjacent to a proposed development site. The developer may have to carry out hydraulic modelling to determine flood levels and accurately assess the flood risk. 5.6.3 Clay Cross – River Rother There is a small area of Flood Zone 2 and 3 to the east of Clay Cross, adjacent to some proposed development sites. There are no modelled or historical flood levels at this location and may have to be determined by the developers. 5.6.4 Holymoorside – River Hipper and Tributaries The River Hipper flows to the southeast of Holymoorside with a tributary joining from the northwest. Residential areas around the junction of New Road and Loads Road are located in

Faber Maunsell Chesterfield, Bolsover and North East Derbyshire SFRA 68

Flood Zone 2 and 3 according to the EA’s Flood Zone maps. There are currently no development sites at this location but any sites should consider the risk from the River Hipper and its tributary. In addition, Old Mill pond appears to be elevated and could also pose a threat. 5.6.5 Dronfield and Unstone - River Drone The River Drone passes through the centre of Dronfield. The main area at risk is along Mill Lane, which is located in Flood Zone 2 and 3. There are some defences which offer protection to a 50 year standard but these are likely to be overtopped during a severe flood. This area is not covered by a hydraulic model and, as such, levels would have to be confirmed by the developers as part of a detailed flood risk assessment. Downstream of Mill Lane is Dronfield Sewage Treatment works and an adjacent disused tip. This area is located in Flood Zone 3 and was subjected to flooding in June 2007. This area is also designated for development. As this area is subject to flooding it is providing valuable flood storage area and any development proposals must not remove this without providing compensation storage, as this would increase downstream flood risk. Further downstream is the village of Unstone. There are a few properties on the right bank of the Drone located in Flood Zone 3. Developers in this area may have to confirm flood levels by carrying out hydraulic modelling. 5.6.6 Renishaw, Eckington and Killamarsh – River Rother The largest part of the area consists of fields, many designated as washlands (see NEDDC48, NEDDC43 and NEDDC51). Around Renishaw, downstream of the confluence of the River Rother and Doe Lea, there is a large area at risk including parts of Renishaw Park (see NEDDC34) and a few properties in Eckington (see ID NEDDC48). Further downstream, on the right bank of the Rother, a number of properties along Sheffield Road are at risk. There are no modelled flood levels for this area but the situation should be confirmed by detailed flood risk assessments for sites at potential risk. 5.6.7 Areas of main concern The following areas are assessed as being at significant and/or frequent risk of flooding in NE Derbyshire

 Rotherside Road Industrial Estate, Eckington  Emmett Carr Lane, Reninshaw and downstream industrial land  Mansfield Road, Corbriggs (unnamed watercourse),  Bridge Street, Pilsley (culvert). 5.7 Sewer Flooding Incidents of sewer flooding have been identified by the Severn Trent Water (STW) and Yorkshire Water (YW). These incidents tend to be isolated in nature and do not generally affect a large number of properties. Measures to deal with flooding problems in the study area associated with sewers are the responsibility of STW. The water companies have a register of properties flooded by sewers (DG5 register) and are charged with reducing the flood risk from sewers. It is believed that flooding of sewers within the study area is not related to water backing up in the system due to high water levels in the rivers in the catchment but more due to inadequate capacity or maintenance problems (e.g. blockages).

Severn Trent Water and Yorkshire Water have provided relevant extracts from their DG5 register for the Chesterfield, Bolsover and NE Derbyshire areas.

5.7.1 Sewer Flooding in Chesterfield Isolated locations within the council area have been identified by YW that have been at risk of sewer flooding in the past and include their risk status; however the mechanism for most of the locations is unknown. These locations are listed in Table 6 and shown on Drawing Nos. 55328/C/HF/O, and 55328/C/HF/01 to /03 in Appendix D.

Faber Maunsell Chesterfield, Bolsover and North East Derbyshire SFRA 69

Table 6: CBC Sewerage flooding Description of ID Problem Location Sub-catchment problems\comments External flooding recorded for 1 CHE230 Boythorpe Road Chesterfield property, probability 1 in 10 years External flooding recorded for 1 CHE231 Brimington Road Chesterfield property, probability 1 in 10 years External flooding recorded for 1 CHE232 Calow Lane Hasland property, probability 1 in 10 years External flooding recorded for 1 CHE233 Clayton Street Chesterfield property, probability 1 in 10 years External flooding recorded for 2 CHE234 Dale Close Staveley properties, probability 1 in 10 years External flooding recorded for 1 CHE235 Harvey Road Chesterfield property, probability 1 in 10 years External flooding recorded for 1 CHE236 Hasland Road Hasland property, probability 1 in 10 years External flooding recorded for 1 CHE237 Hazelhurst Lane Stonegravels property, probability 1 in 10 years External flooding recorded for 1 CHE238 Lincoln Street Birdholme property, probability 1 in 10 years External flooding recorded for 1 CHE239 Linden Avenue Hasland property, probability 1 in 10 years External flooding recorded for 1 CHE240 Litton Close Staveley property, probability 1 in 10 years External flooding recorded for 2 CHE241 Manor Road Brimington properties, probability 1 in 10 years External flooding recorded for 1 CHE242 May Avenue Old Whittington property, probability 1 in 10 years External flooding recorded for 1 CHE243 Morley Avenue Ashgate property, probability 1 in 10 years External flooding recorded for 1 CHE244 Off Meltham Lane Brimington property, probability 1 in 10 years External flooding recorded for 1 CHE245 Park Lane Newbold property, probability 1 in 10 years External flooding recorded for 2 CHE246 Pottery Lane East Whittington properties, probability 1 in 10 years External flooding recorded for 1 CHE247 Queens Park Chesterfield property, probability 1 in 10 years External flooding recorded for 1 CHE248 Close Inkersall property, probability 1 in 10 years Whittington External flooding recorded for 4 CHE249 Sheffield Road Moor properties, probability 1 in 10 years External flooding recorded for 6 CHE250 St Augustines Road St Augustines properties, probability 1 in 10 years External flooding recorded for 1 CHE251 Station Lane Old Whittington property, probability 1 in 10 years External flooding recorded for 1 CHE252 Station Road Old Whittington property, probability 1 in 10 years External flooding recorded for 3 CHE253 Station Road Hollingwood properties, probability 1 in 10 years External flooding recorded for 1 CHE255 The Green Hasland property, probability 1 in 10 years External flooding recorded for 1 CHE256 Walton Crescent Chesterfield property, probability 1 in 10 years External flooding recorded for 1 CHE257 Wellington Street New Whittington property, probability 1 in 10 years External flooding recorded for 1 CHE258 Bacons Lane Birdholme property, probability 1 in 20 years External flooding recorded for 1 CHE259 Barrow Hill Staveley property, probability 1 in 20 years

Faber Maunsell Chesterfield, Bolsover and North East Derbyshire SFRA 70

Description of ID Problem Location Sub-catchment problems\comments External flooding recorded for 4 CHE260 Derby Road St Augustines properties, probability 1 in 20 years External flooding recorded for 1 CHE261 Hasland By-Pass/Derby Rd Jn Hasland property, probability 1 in 20 years External flooding recorded for 1 CHE262 Milldale Close Ashgate property, probability 1 in 20 years External flooding recorded for 1 CHE263 Moorland View Road Tapton property, probability 1 in 20 years External flooding recorded for 1 CHE264 Pottery Lane West Whittington property, probability 1 in 20 years Whittington External flooding recorded for 4 CHE265 Sheffield Road Moor properties, probability 1 in 20 years External flooding recorded for 2 CHE266 Station Road Brimington properties, probability 1 in 20 years External flooding recorded for 2 CHE267 Hawthorne Street Birdholme properties, probability 1 in 30 years External flooding recorded for 1 CHE268 Hazel Drive Walton property, probability 1 in 30 years External flooding recorded for 1 CHE269 Ingleton Road Hasland property, probability 1 in 30 years External flooding recorded for 1 CHE270 Kingsmede Avenue Walton property, probability 1 in 30 years External flooding recorded for 1 CHE271 Moorland View Road Tapton property, probability 1 in 30 years External flooding recorded for 1 CHE272 Sycamore Road Hollingwood property, probability 1 in 30 years External flooding recorded for 1 CHE273 Derby Road St Augustines property, probability 2 in 10 years External flooding recorded for 1 CHE274 Middlecroft Road Staveley property, probability 2 in 10 years External flooding recorded for 5 CHE275 Newbridge Drive Brimington properties, probability 2 in 10 years External flooding recorded for 2 CHE276 North Crescent properties, probability 2 in 10 years External flooding recorded for 4 CHE277 St Augustines Road St Augustines properties, probability 2 in 10 years External flooding recorded for 1 CHE278 Station Lane Old Whittington property, probability 2 in 10 years External flooding recorded for 1 CHE279 Storforth Lane Hasland property, probability 2 in 10 years External flooding recorded for 1 CHE280 The Grove Poolsbrook property, probability 2 in 10 years Internal flooding recorded for 1 CHE281 Chatsworth Road Brampton property, probability <1 in 30 years Internal flooding recorded for 1 CHE282 Hartington Road Dronfield property, probability <1 in 30 years Internal flooding recorded for 1 CHE283 Market Street Eckington property, probability <1 in 30 years Internal flooding recorded for 1 CHE284 New Street Chesterfield property, probability <1 in 30 years Internal flooding recorded for 3 CHE285 Park Road Chesterfield properties, probability <1 in 30 years Internal flooding recorded for 1 CHE286 Pottery Lane East Whittington property, probability 1 in 10 years Internal flooding recorded for 1 CHE287 Wharf Lane Chesterfield property, probability 1 in 10 years Internal flooding recorded for 3 CHE288 Chatsworth Road Brampton properties, probability 1 in 10 years Internal flooding recorded for 1 CHE289 Chester Street Brampton property, probability 1 in 20 years

Faber Maunsell Chesterfield, Bolsover and North East Derbyshire SFRA 71

Description of ID Problem Location Sub-catchment problems\comments Internal flooding recorded for 1 CHE290 Dale Close Staveley property, probability 1 in 20 years Internal flooding recorded for 1 CHE291 Fieldhead Way Newbold property, probability 1 in 20 years Internal flooding recorded for 1 CHE292 Harvest Way Ashgate property, probability 1 in 20 years Internal flooding recorded for 1 CHE293 Kirkstone Road Newbold property, probability 1 in 20 years Internal flooding recorded for 1 CHE294 Manor Road Ashgate property, probability 1 in 20 years Internal flooding recorded for 1 CHE295 Stand Road Newbold property, probability 1 in 20 years Internal flooding recorded for 1 CHE296 Wharf Lane Chesterfield property, probability 1 in 20 years Internal flooding recorded for 2 CHE297 Barn Close Newbold properties, probability 1 in 20 years Internal flooding recorded for 4 CHE298 Cranborne Road Newbold properties, probability 1 in 20 years Internal flooding recorded for 1 CHE299 Old Road Brampton property, probability 1 in 30 years Internal flooding recorded for 2 CHE300 Road Mastin Moor properties, probability 1 in 30 years Internal flooding recorded for 3 CHE301 Calow Lane Hasland properties, probability 1 in 30 years Internal flooding recorded for 3 CHE302 Kingsmede Avenue Walton properties, probability 1 in 30 years Internal flooding recorded for 1 CHE303 North Crescent Duckmanton property, probability 2 in 10 years External flooding recorded for 1 CHE304 Brook Drive Brimington property, probability 1 in 10 years External flooding recorded for 1 CHE305 Cromford Drive Staveley property, probability 1 in 10 years External flooding recorded for 1 CHE306 Derby Road St Augustines property, probability 1 in 10 years External flooding recorded for 1 CHE307 Dunston Road Newbold Moor property, probability 1 in 10 years External flooding recorded for 2 CHE308 Tapton Way Calow properties, probability 1 in 10 years External flooding recorded for 1 CHE309 Whitehouses Hasland property, probability 1 in 10 years External flooding recorded for 1 CHE310 White House Hasland property, probability 1 in 20 years External flooding recorded for 1 CHE312 Whitehouses Hasland property, probability 2 in 10 years External flooding recorded for 1 CHE311 Brearley Road New Whittington property, probability 2 in 10 years

5.7.2 Sewer Flooding in Bolsover Isolated locations have been identified by STW and YW that have been prone to sewer flooding in the past; however the mechanism for most of the locations is unknown. For most of these locations, external gardens and roads were affected. These locations are listed in Table 7 and shown on Drawing Nos. 55328/B/HF/O, and 55328/B/HF/01 to /10 in Appendix D. Table 7: BDC Sewerage flooding Description of ID Problem Location Sub-catchment problems\comments BDC37 East View Langwith Junction Highway BDC38 The Bassett Langwith Junction External Garden

Faber Maunsell Chesterfield, Bolsover and North East Derbyshire SFRA 72

Description of ID Problem Location Sub-catchment problems\comments BDC39 Vaughan Place Langwith Junction External Garden BDC41 Central Road Shirebrook Highway BDC42 Chatsworth Avenue Shirebrook External Garden BDC43 Church Drive Shirebrook External Garden BDC44 Elm Tree Avenue Shirebrook External Garden BDC45 Market Close Shirebrook Highway & External Garden BDC46 Portland Road/Market Street Shirebrook Highway BDC48 Recreation Road Shirebrook Internal Domestic BDC49 Gloves Lane Blackwell External Public Open Space BDC50 Victoria Drive Blackwell External Garden BDC51 Barlborough Road Clowne Highway BDC52 Church Lane Clowne Public Open Space BDC53 Hollin Hill Road Clowne Highway External Non Domestic BDC54 Neale Street Clowne Highway BDC55 Southfields Clowne Highway & External Garden BDC56 Elmton Road Cresswell External Garden BDC57 Skinner Street Cresswell Highway BDC58 Devonshire Drive Langwith Highway BDC60 Pool Close Pinxton External Garden BDC61 Church Lane Pleasley External Garden BDC62 Rotherham Road Highway BDC63 Station Road Scarcliffe External Public Open Space BDC64 Alfreton Road South Normanton Highway BDC65 Birchwood Lane South Normanton Highway & External garden BDC66 Downing Street South Normanton External Garden & Internal BDC67 George Street South Normanton External Garden BDC69 North Close South Normanton External Garden & Internal BDC70 North Street South Normanton Highway BDC71 Brook Street Tibshelf Highway & External garden BDC72 High Street Tibshelf External Garden BDC73 Tibshelf Road Westhouses Highway & External Garden BDC74 Station Road Whitwell External Public Open Space External flooding recorded for 1 BDC109 Carr Vale Road Bolsover property, probability 1 in 10 years External flooding recorded for 1 BDC105 Main Street Palterton property, probability 1 in 10 years External flooding recorded for 3 BDC104 Manor Court Road Bolsover properties, probability 1 in 10 years External flooding recorded for 1 BDC106 Rylah Hill Palterton property, probability 1 in 10 years External flooding recorded for 4 BDC108 Sutton Hall Road Bolsover properties, probability 1 in 10 years External flooding recorded for 2 BDC107 The Hill Glapwell properties, probability 1 in 10 years Internal flooding recorded for 1 BDC103 Manor Court Road Bolsover property, probability 1 in 10 years

5.7.3 Sewer Flooding in North East Derbyshire Isolated locations have been identified by STW and YW that have been prone to sewer flooding in the past; however the mechanism for most of the locations is unknown. For most of these locations, external gardens and roads were affected. These locations are listed in Table 8 and shown on Drawing Nos. 55328/NE/HF/O, and 55328/NE/HF/01 to /08 in Appendix D.

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Table 8: NEDDC Sewer flooding Description of ID Problem Location Sub-Catchment problems\comments NEDDC12 Moor Road Internal Domestic NEDDC13 Strettea Lane Higham Internal Domestic NEDDC14 Harewood Crescent Old External Garden NEDDC15 Padley Wood Lane Pilsley Internal Domestic NEDDC16 A61 External Public Open Space NEDDC17 Hallfieldgate Lane Shirland External Public Open Space NEDDC18 Pit Lane Shirland External Garden NEDDC20 Temperance Hill External Garden External flooding recorded for 1 NEDDC58 North Crescent Killamarsh property, probability 1 in 10 years External flooding recorded for 6 NEDDC59 Netherthorpe Lane Killamarsh properties, probability 1 in 20 years External flooding recorded for 1 NEDDC60 Netherthorpe Lane Killamarsh property, probability 1 in 20 years External flooding recorded for 1 NEDDC61 Spooner Drive Killamarsh property, probability 1 in 10 years External flooding recorded for 2 NEDDC62 Royale Close Eckington properties, probability 1 in 10 years External flooding recorded for 1 NEDDC63 Campion Drive Killamarsh property, probability 1 in 20 years External flooding recorded for 1 NEDDC64 Southgate Eckington property, probability 1 in 20 years External flooding recorded for 1 NEDDC65 Royale Close Eckington property, probability 2 in 10 years External flooding recorded for 1 NEDDC66 Carr Lane Dronfield property, probability 1 in 10 years External flooding recorded for 1 NEDDC67 Eastfield Road Dronfield property, probability 1 in 10 years External flooding recorded for 1 NEDDC68 Holmley Lane Dronfield property, probability 1 in 10 years External flooding recorded for 1 NEDDC69 Mill Lane Dronfield property, probability 1 in 10 years External flooding recorded for 2 NEDDC70 Mill Lane Dronfield properties, probability 2 in 10 years Internal flooding recorded for 2 NEDDC71 Green Lane Dronfield properties, probability 1 in 20 years Internal flooding recorded for 1 NEDDC72 Stubley Lane Dronfield property, probability 1 in 30 years External flooding recorded for 1 NEDDC73 Carlton Close Danesmoor property, probability 1 in 10 years External flooding recorded for 1 NEDDC74 Cemetery Road Danesmoor property, probability 1 in 10 years External flooding recorded for 1 NEDDC75 Guildford Close Danesmoor property, probability 1 in 10 years External flooding recorded for 1 NEDDC76 Hazel Drive property, probability 1 in 10 years External flooding recorded for 1 NEDDC77 High Street Claycross property, probability 1 in 10 years External flooding recorded for 1 NEDDC78 Market Street Clay Cross property, probability 1 in 10 years External flooding recorded for 1 NEDDC79 Mill Lane Wingerworth property, probability 1 in 10 years External flooding recorded for 1 NEDDC80 Northside New Tupton property, probability 1 in 10 years External flooding recorded for 1 NEDDC81 Shakespeare Street property, probability 1 in 10 years External flooding recorded for 2 NEDDC82 Staveley Road Duckmanton properties, probability 1 in 10 years External flooding recorded for 3 NEDDC84 Top Road Calow properties, probability 1 in 10 years External flooding recorded for 1 NEDDC85 Williamthorpe Close property, probability 1 in 10 years

Faber Maunsell Chesterfield, Bolsover and North East Derbyshire SFRA 74

Description of ID Problem Location Sub-Catchment problems\comments External flooding recorded for 1 NEDDC86 Williamthorpe Road North Wingfield property, probability 1 in 10 years External flooding recorded for 1 NEDDC87 Birkin Lane West property, probability 1 in 20 years External flooding recorded for 1 NEDDC88 Bridge Street Clay Cross property, probability 1 in 20 years External flooding recorded for 8 NEDDC89 Joseph Fletcher Drive Wingerworth properties, probability 1 in 20 years External flooding recorded for 1 NEDDC90 Linden Avenue Clay Cross property, probability 1 in 20 years External flooding recorded for 2 NEDDC91 Cemetery Road Danesmoor properties, probability 2 in 10 years External flooding recorded for 1 NEDDC92 Linden Avenue Clay Cross property, probability 2 in 10 years External flooding recorded for 1 NEDDC93 Nethermoor Road New Tupton property, probability 2 in 10 years External flooding recorded for 2 NEDDC94 Northside New Tupton properties, probability 2 in 10 years External flooding recorded for 1 NEDDC95 Pilsley Road Danesmoor property, probability 2 in 10 years External flooding recorded for 2 NEDDC96 Williamthorpe Road North Wingfield properties, probability 2 in 10 years Internal flooding recorded for 1 NEDDC97 Park Row Clay Cross property, probability 1 in 10 years Internal flooding recorded for 1 NEDDC98 Williamthorpe Road North Wingfield property, probability 1 in 10 years Internal flooding recorded for 1 NEDDC99 Main Road Cutthorpe property, probability 1 in 20 years Internal flooding recorded for 1 NEDDC100 Mansfield Road Hasland property, probability 1 in 30 years Internal flooding recorded for 1 NEDDC101 Williamthorpe Close North Wingfield property, probability 2 in 10 years External flooding recorded for 1 NEDDC102 Top Road Calow property, probability 2 in 10 years

5.8 Groundwater flooding and Surface Water Run-off The EA do not have any details of historical flooding relating to groundwater. However, they were able to provide a plan showing the location of an outcrop of magnesium limestone (Figure 6, page 48) which is susceptible to groundwater flooding.

The Environment Agency Midlands Region’s East Area does not have any information relating to groundwater flooding issues within the area.

Surface water runoff from natural springs causing flooding to public open space, gardens and paths have been identified in Barlborough and Bolsover (see BDC11, BDC15 and BDC17). Bainbridge Road in New Bolsover has suffered historical groundwater flooding to grass public open space, footpath & bus shelter areas (see BDC17). 5.8.1 River Hipper Catchment The catchment is predominantly underlain with impermeable rocks of lower and middle coal measures with small area of Millstone Grit in the upper catchment. The catchment standard percentage runoff (SPRHOST) is given as 26.0. The Base Flow Index derived from the hydrology of Soil Types (BFIHOST) is 0.554 (Environment Agency, River Hipper Pre Feasibility Study, March 2005) and is a measure of the proportion of the flow in the river that is attributed to the base flow (i.e. flow in dry weather). A groundwater driven catchment would have a high index and a runoff driven catchment would have a low index. The soil that dominates the Hipper catchment is slowly permeable and seasonally water logged, it suggests the potential for relatively high percentage runoffs. The remaining soils are a mixture of well drained and less well drained soils. The relatively low SPRHOST value given is therefore slightly incongruous.

Faber Maunsell Chesterfield, Bolsover and North East Derbyshire SFRA 75

5.8.2 River Whitting Catchment The catchment standard percentage runoff (SPRHOST) is given as 25.1. The Base Flow Index is 0.536 (Jacobs Babtie flood study audit trail FEH pooling group analysis, River Whitting at Sheepbridge). The geology is Lower Coal Measure sandstones and shales. The FEH catchment descriptors indicate a fairly permeable catchment. The UK Soils map shows the catchment is mainly characterised by slowly permeable seasonally waterlogged soils and disturbed soils, with only some pockets of well-drained soils. 5.8.3 Barlow Brook Catchment The catchment standard percentage runoff (SPRHOST) is given as 29.0. The Base Flow Index is 0.498 (Jacobs Babtie flood study audit trail FEH pooling group analysis, Barlow Brook at Cobnar Wood). The majority of the soils are classed as ‘Bardsey Stagnogley Soils’ originating from carboniferous mudstone with interbedded sandstone. The soil is described as slowly permeable and seasonally waterlogged in the Soil Survey of England and Wales, suggesting the potential for high percentage runoffs. This would suggest that the risk of groundwater flooding is low/medium . 5.8.4 Riddings Brook Catchment The catchment standard percentage runoff (SPRHOST) is given as 29.7. The Base Flow Index is 0.454 (Jacobs Babtie flood study audit trail FEH pooling group analysis, Riddings Brook at Newbold moor). The majority of the soils are classed as ‘Bardsey Stagnogley Soils’ originating from carboniferous mudstone with interbedded sandstone. The soil is described as slowly permeable and seasonally waterlogged in the Soil Survey of England and Wales. The geology of the region is Lower Coal Measure sandstones and shales. This would suggest that the risk of groundwater flooding is low/medium . 5.8.5 River Drone Catchment The catchment standard percentage runoff (SPRHOST) is given as 18.7. The Base Flow Index is 0.615 (Jacobs Babtie flood study audit trail FEH pooling group analysis, River Drone at Footbridge). The geology is Lower Coal Measure sandstones and shales. The FEH catchment descriptors indicate a faily permeable catchment. The UK Soils map shows the catchment mainly characterised by slowly permeable seasonally waterlogged soils and disturbed soils, with only some pockets of well-drained soils. This would suggest that the risk of groundwater flooding is low/medium . 5.8.6 River Doe Lea Catchment The soils in the catchment are mainly slowly permeable of mudstone and sandstone origin, with substantial areas of disturbed soil where there are restored opencast coal workings and slagheaps. The density of the drainage network is relatively sparse, perhaps a reflection of the shallow relief, geology and soil type. The flow regime is affected by mine drainage, with a net import of water. This would suggest that the risk of groundwater flooding is low/medium . 5.8.7 East of Bolsover The principal groundwater bearing geology in the section of the survey area within the Environment Agency East Area Groundwater Team’s geographical area are the Cadeby Formation, the Carboniferous Coal Measures and the fluvioglacial deposits, associated with the areas river network. The Cadeby Formation, formerly known as the Lower Magnesian Limestone, is exposed in outcrop in the east of the search area and covers most of the specified survey area in the Environment Agency Midlands Region’s East Area geographical area. The Carboniferous Coal Measures are exposed in outcrop to the west of the Cadeby Formation. The geological beds dip from west to east at an angle somewhere between 1 – 3 degrees such that the Cadeby Formation is underlain by the Coal Measures. This would suggest that the risk of groundwater flooding is medium/high . The Environment Agency does not monitor groundwater levels within the Carboniferous Coal measures and therefore has no groundwater level data for them. The Environment Agency does record groundwater level data for the Cadeby Formation and groundwater contours for this are presented on the map in Figure 6.

Faber Maunsell Chesterfield, Bolsover and North East Derbyshire SFRA 76

5.9 Other sources of flooding Locations at risk of other sources of flooding including artificial sources, surface water run-off, land drainage, flooding form structure failures, flooding form highways and a combination of any of the above sources has been identified within Chesterfield, Bolsover and North East Derbyshire. Details of each location can be found in Appendix A. A reference number on the register relates to the historical flooding drawings in Appendix D. 5.9.1 Other Sources of Flooding in Chesterfield Throughout Chesterfield there are many locations at risk of land drainage (see CHE162, CHE163, CHE159). Staveley Road in Poolsbrook (see CHE165) can be flooded due to land drainage runoff. The mechanism is unknown There are lots of locations flooded due to inadequate capacity of culverts causing flooding to road and properties (see CHE1, CHE4, CHE5). 5.9.2 Other Sources of Flooding in Bolsover Shirebrook at the east of Bolsover is an area that has historically been at risk of flooding from surface water run-off (see BDC40). East of Shirebrook excessive surface water run-off from the former coal tip often forces the closure of Sookholme Road and presents problems for the farming community at Sookholm (see BDC08). Runoff from fields and highways caused flooding problems to properties on Elm Tree Avenue in November 2000 and June 2007 (see BDC30). In South Normanton (south Bolsover) there were incidents of surface water runoff from playing fields and public open spaces causing flooding to several properties (see BDC31). Inadequate capacity and blockages of culverts also presented problems to open spaces and car parks in the area (see BDC32, IBDC33 and BDC27). In Clowne, the flooding problems appear to be related to inadequacies with the culverts and are, therefore, fluvial in nature. There are a number of sewer related flooding incidents as discussed above. In addition, there is a potentially significant risk from Harlesthorpe Dam. 5.9.3 Other Sources of Flooding in North East Derbyshire In NEDDC there were not many incidents of flooding from other sources. The majority of them were due to surface water runoff (see NEDDC19, NEDDC10, NEDDC08).

Strategic Assessment of Flood Risk

Faber Maunsell Chesterfield, Bolsover and North East Derbyshire SFRA 80

6 Strategic Assessment of Flood Risk

6.1 Plans and Mapping 6.1.1 Flood Zone Maps The Environment Agency has produced Flood Zone maps for the whole country to identify areas that are at risk of flooding from rivers. The Flood Zones are defined as follows:

 Flood Zone 1 comprises land with less than a 1 in 1000 year chance of annual probability of flooding from rivers.  Flood Zone 2 comprises land assessed as having between a 1 in 100 and 1 in 1000 annual probability of river flooding in any year.  Flood Zone 3 is sub divided in two categories as follows: - Flood Zone 3a comprises land assessed as having a 1 in 100 or greater annual probability of river flooding in any year. - Flood Zone 3b is classed as functional floodplain and therefore at a higher risk of flooding than Flood Zone 3a. PPS25 defines a functional floodplain as land where water has to flow or be stored in times of flood. PPS25 states that this land would flood with an annual probability of 1 in 20 or is designed to flood in an extreme (1 in 100 year) flood (or at another agreed probability).

The EA’s Flood Zone maps assume no flood defences are in place. The reason for this is because, although flood defences may reduce the risk of flooding, there will always be a residual risk due to a breach or overtopping.

The Flood Zone maps included in this SFRA report have used the EA’s maps and supplemented them with additional information as follows. The extents of June 2007 flood provided by the EA have been incorporated as part of Flood Zone 2. These flood extents are to become the new Flood Zone 2 outline on the next issue of the EA’s maps. Flood Zone 3 has been defined by showing the worst-case outline of the original Flood Zone 3 outline taken from the EA’s maps, combined with the 100 year outline taken from the hydraulic models. Flood Zone 3b (functional floodplain) has been produced by combining the 1 in 25 year outline taken from the hydraulic model combined with designated flood storage areas and washlands. It should be noted that, at this stage, the actual extents of Flood Zone 3b is being agreed between the Environment Agency and the prospective councils. The outlines shown on the Flood Zone maps are for indicative purposes only. Areas that would be Flood Zone 3b but are already developed have been downgraded to Flood Zone 3a. As discussed in section 3.3 there is no climate change modelling/flood extents available for the catchment area. However, professional judgement has been used to assess the likely impact of climate change for key locations taking into account the flood outlines. Refer to Section 6.3 for more information.

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Refer to the following drawings in Appendix D for the Flood Zone maps: Drawing Name Drawing Number Flood Zones - Chesterfield 55328/C/F/01 Flood Zones – Bolsover Overview 55328/B/F/O Flood Zones – Bolsover Area 01 55328/B/F/01 Flood Zones – Bolsover Area 02 55328/B/F/02 Flood Zones - North East Derbyshire Overview 55328/NE/F/ O Flood Zones - North East Derbyshire Area 01 55328/NE/F/01 Flood Zones - North East Derbyshire Area 02 55328/NE/F/02 Flood Zones - North East Derbyshire Area 03 55328/NE/F/03

6.1.2 Historical Flooding Locations at risk of flooding have been identified through the Environment Agency’s Flood Zone maps and historical flooding records, information from each of the LPAs, Derbyshire County Council, Yorkshire Water and Severn Trent Water. A register of flood risk locations has been created from the data collection stage. Details of each location can be found in Appendix A. A reference number on the register relates to the following drawing in Appendix D: Drawing Name Drawing Number Historic Flooding, Flood Storage and Defences - Chesterfield Overview 55328/C/HF/O Historic Flooding, Flood Storage and Defences - Chesterfield Area 01 55328/C/HF/01 Historic Flooding, Flood Storage and Defences - Chesterfield Area 02 55328/C/HF/02 Historic Flooding, Flood Storage and Defences - Chesterfield Area 03 55328/C/HF/03 Historic Flooding, Flood Storage and Defences - Bolsover Overview 55328/B/HF/O Historic Flooding, Flood Storage and Defences - Bolsover Area 01 55328/B/HF/01 Historic Flooding, Flood Storage and Defences - Bolsover Area 02 55328/B/HF/02 Historic Flooding, Flood Storage and Defences - Bolsover Area 03 55328/B/HF/03 Historic Flooding, Flood Storage and Defences - Bolsover Area 04 55328/B/HF/04 Historic Flooding, Flood Storage and Defences - Bolsover Area 05 55328/B/HF/05 Historic Flooding, Flood Storage and Defences - Bolsover Area 06 55328/B/HF/06 Historic Flooding, Flood Storage and Defences - Bolsover Area 07 55328/B/HF/07 Historic Flooding, Flood Storage and Defences - Bolsover Area 08 55328/B/HF/08 Historic Flooding, Flood Storage and Defences - Bolsover Area 09 55328/B/HF/09 Historic Flooding, Flood Storage and Defences - Bolsover Area 10 55328/B/HF/10 Historic Flooding, Flood Storage and Defences – North East Derbyshire Overview 55328/B/NE/O Historic Flooding, Flood Storage and Defences – 55328/NE/HF/01 North East Derbyshire Area 01 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/02 North East Derbyshire Area 02 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/03 North East Derbyshire Area 03 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/04 North East Derbyshire Area 04 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/05 North East Derbyshire Area 05 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/06 North East Derbyshire Area 06 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/07 North East Derbyshire Area 07 Historic Flooding, Flood Storage and Defences – 55328/NE/HF/08 North East Derbyshire Area 08

6.1.3 Development sites Potential development sites and development commitments have been provided by Chesterfield Borough Council, Bolsover District Council and North East Derbyshire District Council based on Local Plan Development sites and known land availability. Development sites comprise a mixture of the following:

 Commitments – Sites which currently have either outline or detailed planning permission. These sites can not be influenced by the SFRA unless the planning application lapses or a

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major change to the planning application is received. There are development site commitments for Chesterfield, Bolsover and North East Derbyshire;  Local Plan Development sites – Areas which have been identified in the Local Development Plan for future redevelopment. These development sites generally cover a large area but do not relate directly to a specific development site. Development of these areas would come forward as and when land becomes available. Local Plan Development sites cover Chesterfield, Bolsover and North East Derbyshire;  Site Testing – Known land availability with preliminary aspirations for the type of development to be located there. These development sites can be directly influenced by the SFRA. Site testing development sites are located in Bolsover only. A list of development sites has been compiled and this can be found in Appendix B. Flood risk reviews at each development site are contained in an development site matrix in the addendum of this report. A reference number on the list of development sites and on the development site matrix relates to the following drawing in Appendix D: Drawing Name Drawing Number Development Sites - Chesterfield Overview 55328/C/A/O Development Sites - Chesterfield Area 01 55328/C/A/01 Development Sites - Chesterfield Area 02 55328/C/A/02 Development Sites - Chesterfield Area 03 55328/C/A/03 Development Sites - Chesterfield Area 04 55328/C/A/04 Development Sites - Chesterfield Area 05 55328/C/A/05 Development Sites - Chesterfield Area 06 55328/C/A/06 Development Sites - Chesterfield Area 07 55328/C/A/07 Development Sites - Chesterfield Area 08 55328/C/A/08 Development Sites - Chesterfield Area 09 55328/C/A/09 Development Sites - Chesterfield Area 10 55328/C/A/10 Development Sites - Chesterfield Area 11 55328/C/A/11 Development Sites - Chesterfield Area 12 55328/C/A/12 Development Sites - Bolsover Overview 55328/B/A/O Development Sites - Bolsover Area 01A 55328/B/A/01- A Development Sites - Bolsover Area 01B 55328/B/A/01- B Development Sites - Bolsover Area 01C 55328/B/A/01- C Development Sites - Bolsover Area 01D 55328/B/A/01 - D Development Sites - Bolsover Area 01E 55328/B/A/01 - E Development Sites - Bolsover Area 01F 55328/B/A/01 - F Development Sites - Bolsover Area 02A 55328/B/A/02 - A Development Sites - Bolsover Area 02B 55328/B/A/02 - B Development Sites - Bolsover Area 02C 55328/B/A/02 - C Development Sites - Bolsover Area 03 55328/B/A/03 Development Sites - Bolsover Area 04 55328/B/A/04 Development Sites - Bolsover Area 05 55328/B/A/05 Development Sites - Bolsover Area 06 55328/B/A/06 Development Sites - Bolsover Area 07 55328/B/A/07 Development Sites - Bolsover Area 08 55328/B/A/08 Development Sites - Bolsover Area 09A 55328/B/A/09 - A Development Sites - Bolsover Area 09B 55328/B/A/09 - B Development Sites - Bolsover Area 10A 55328/B/A/10 - A Development Sites - Bolsover Area 10B 55328/B/A/10 - B Development Sites - Bolsover Area 11 55328/B/A/11 Development Sites - Bolsover Area 12 55328/B/A/12 Development Sites - Bolsover Area 13 55328/B/A/13 Development Sites - Bolsover Area 14 55328/B/A/14 Development Sites - Bolsover Area 15 55328/B/A/15 Development Sites - Bolsover Area 16 55328/B/A/16 Development Sites - Bolsover Area 17 55328/B/A/17 Development Sites - North East Derbyshire Overview 55328/NE/A/O Development Sites - North East Derbyshire Area 01 55328/NE/A/01 Development Sites - North East Derbyshire Area 02 55328/NE/A/02 Development Sites - North East Derbyshire Area 03 55328/NE/A/03 Development Sites - North East Derbyshire Area 04 55328/NE/A/04 Development Sites - North East Derbyshire Area 05 55328/NE/A/05 Development Sites - North East Derbyshire Area 06 55328/NE/A/06 Development Sites - North East Derbyshire Area 07 55328/NE/A/07

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Development Sites - North East Derbyshire Area 08 55328/NE/A/08 Development Sites - North East Derbyshire Area 09 55328/NE/A/09 Development Sites - North East Derbyshire Area 10 55328/NE/A/10

6.1.4 Assets Information on the location and condition of assets was obtained from the Environment Agency and supplemented with further information provided by each council. An asset has been defined as ‘something which could cause flooding if it failed’ and includes culverts, weirs, flap valves, outfalls etc. Assets for each area are shown on the following drawings in Appendix D: Drawing Name Drawing Number Assets - Chesterfield 55328/C/AS/01 Assets - Bolsover Overview 55328/B/AS/O Assets - Bolsover Area 01 55328/B/AS/01 Assets - Bolsover Area 02 55328/B/AS/02 Assets - North East Derbyshire Overview 55328/NE/AS/O Assets - North East Derbyshire Area 01 55328/NE/AS/01

6.2 Flood risk profile A flood defence breach analysis has not been carried out as part of this study. An assessment has been made of the flood risk to people in the study area, based on professional judgement and national guidance. The assessment has been carried out at defended areas or areas at risk of fluvial flooding where hydraulic modelling data exists. The results of this analysis have been used to judge which potential future development sites, or parts of potential development sites, are at a greater flood risk. Certain types of development (i.e. residential) can be directed away from these high risk zones. 6.2.1 Flood defence breach and overtopping In a major flood event where a river is confined within flood defences, there may be a difference between the water level on one side of the flood defence and the ground level in the defended area behind that defence. If that defence were then to fail, whether through the collapse of a floodwall or the breaching of an embankment, there would be a sudden inrush of flood water into the defended area. The velocity and depth of water cascading through a breach could be significant enough to be a hazard to people. The premature failure of a flood defence structure is by its nature a residual risk, but its potentially fatal consequences dictate that it be given serious consideration in a flood risk assessment (especially in relation to new development). As flood water pours through a breach it will disperse, and its velocity and depth will decrease with distance from the breach. At some distance from the breach the velocity and depth of water will have diminished to a point where an adult is capable of standing upright in the flow. This is deemed to be the outer edge of the rapid inundation hazard zone. The distance of this point from the defence line and the width of the hazard zone, will be determined by the flood level / ground level difference (head of water) and the width of the breach. Defences with an indicative SoP less than 100 years are likely to be overtopped during a severe flooding event . Tables 9 and 10 provide a guide to the danger to people at various distances behind flood defences for overtopping and breaching respectively (assuming that either will occur during the lifetime of the development). Table 9 shows the flood hazard with distance from a flood defence for breaches with different water levels above floodplain level, assuming a flat and clear flood plain (as extracted from the EA/DEFRA document FD2321/TR2 – Flood Risks to People Phase 2, March 2006).

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Table 9: Danger to people from breaching relative to distance from defence

The following table shows the flood hazard for overtopping with distance from a flood defence for different water levels above the defence crest, assuming a flat and clear floodplain (as extracted from the EA/DEFRA document FD2321/TR2 – Flood Risks to People Phase 2, March 2006).

Table 10: Danger to people from overtopping relative to distance from defence

Danger to people is estimated using a formula for calculating the flood hazard rating, which can be expressed as a combination of flood depth, velocity and debris. Hydraulic modelling or the use of results from an existing assessment is needed to accurately predict flood depth and velocity. The Flood Risks to People project has developed the following equation to relate the flood hazard to flood depth, velocity and debris factor: Flood Hazard Rating = (( v + 0.5) * D) + DF Where: v = velocity (m/s) D = depth (m)

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DF = debris factor Table 11 can be used to estimate the danger to people if velocities and depths are known (as extracted from the EA/DEFRA document FD2320/TR2 – Framework and guidance for assessing and Managing Flood Risk for New Development – Full documentation and tools, March 2005). Table 11: Danger to people for different combinations of depth and velocity

For locations within Chesterfield, Bolsover and North East Derbyshire located within Flood Zone 1 that are a significant distance away from flood defences; the flood hazard is low. For the majority of the defences in the study area, the head above the floodplain was unknown. An assessment was made based on the type of the defences (i.e for new developments located close to soft defences such as earth embankments, a breach scenario is more likely to occur). The flood risk matrix includes results from sites that are at risk from a breach (See Addendum).

The majority of the flood defences in the study area have a SoP below 100 years and, as such, are likely to be overtopped during a severe flooding event. For most of the defences, the head above crest level was unknown. The flood risk matrix includes results from sites that are at risk from overtopping (See Addendum).

6.2.2 Areas of main concern in Chesterfield The areas in Chesterfield at potential risk of breach are:

 The Derby Road (St Augustines) area of Chesterfield (River Rother)  The Rother-Hipper confluence u/s of Station Bridge (Rivers Rother and Hipper)  The Holland Road (Old Whittington) area of Chesterfield (River Rother)  Slitting Mill Farm, (River Rother)  Chatsworth Road, area near Chesterfield (River Hipper)  Ravenside Retail Park, Chesterfield (River Hipper)  Horns Bridge Roundabout (A617), Chesterfield (River Rother) 6.2.3 Areas of main concern in Bolsover River Erewash is adjacent to the boundaries of Bolsover District Council. Properties adjacent to the BDC boundary are protected by flood embankments along the right river bank to a 1 in 100 year standard of protection. A breach analysis for developments behind these defences may be required.

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6.2.4 Areas of main concern in North East Derbyshire There do not appear to be any major flood defences in NE Derbyshire where breach could significantly affect existing or future development sites. 6.3 Climate change Current consensus is that climate change will result in changes to flooding in the UK in the 21 st century. The main changes will be in rainfall patterns and sea levels. Changes in rainfall patterns could result in increases in the intensity and frequency of storms and the depths and duration of seasonal rainfall. Such changes will affect the way in which a river catchment responds. Rivers: - The current guidance recommends increasing peak river flow by 10% up to 2025 and 20% thereafter. Rainfall Intensity (Run-off):- When designing surface water drainage for a new development, the impact of climate change should also be taken into account. It is predicted that climate change will increase the intensity of storms and the volume of rainwater. The existing guidance for assessing the impact of climate change on peak rainfall is summarised in Table 12 below. Table 12: Recommended increases in peak rainfall intensities 1990 to 2025 to 2055 to 2085 to 2025 2055 2085 2115

Peak rainfall intensity + 5% + 10% + 20% + 30%

Current EA guidance (Planning policy statement 25: development and flood risk - practice guide, January 2008) in relation to climate change for the design lives for different types of development are as follows:

 30 years for retail development  60 years for commercial development  100 years for residential development and critical infrastructure 6.3.1 Climate change impacts Current extents of fluvial flooding in the study area are unlikely to increase significantly due to climate change. Although flood levels in the rivers are likely to increase, the change in horizontal extent is unlikely to be excessive. The exception to this rule would be for an area which is currently protected against flooding from either raised man-made defences or natural raised ground, which could be overtopped due to increased river levels. The only flood defence identified as being to an indicative SoP of 100 years is located along the River Erewash, adjacent to Bolsover DC boundary. As such, climate change is unlikely to have a significant effect on flood risk planning within the catchment. Climate change could, however, increase the frequency of flooding at undefended sites or cause existing flood defences to be overtopped more often. This could cause the following:

 Areas of Flood Zone 1 could become Flood Zone 2;  Areas of Flood Zone 2 could become Flood Zone 3;  Areas of Flood Zone 3a could become functional floodplain (Flood Zone 3b);  Current SoP of defences could decrease. 6.4 Land use changes for Chesterfield The Regional Spatial Strategy (RSS8) sets out proposals for the sustainable development of the region’s economy, infrastructure, housing and other land uses. The guiding principle is a sequential approach to finding land for most kinds of development which means that major urban areas and previously developed land should be looked at first. An increase in arable farming can lead to a loss of ponds, bogs and mosses, which has improved agricultural drainage. This trend of improving field drainage is likely to continue; therefore the time between storms and flood peaks may reduce in the future across the study area, increasing flood risk.

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Many tributaries of the main rivers within the study area are forested. It is believed that afforestation can reduce runoff and flood risk if undertaken in a sustainable manner. Although afforestation outside floodplains is beneficial and it can be considered as a catchment wide alleviation measure, afforestation within floodplains is more complex and can cause both positive and negative effects and would need to be subject to a detailed catchment wide hydrological survey. A draft policy on this topic is included in Section 9. Deforestation would have an opposite effect and should be managed appropriately. Washlands have the potential to reduce flood peaks by elevating storage and attenuating runoff volumes. Flood risk can also be reduced by further using the upstream reservoirs for flood storage. A major impact to surface water flooding in built-up areas has been caused by urban-creep (e.g. paving of drives and gardens). New legislation is due to be issued in October which may require planning applications for similar future developments. A draft policy on this topic is also included in Section 9.

Urbanisation, deforestation, afforestation, agricultural intensification or other land use changes can potentially affect runoff and river flows.

6.5 Risk from assets The flood risk associated with assets has been investigated throughout the study area. In assessing these assets, culverts, outfalls, weirs, flap valves, penstocks, sluices, and gabions have been included. Weirs are constructed to raise upstream water levels. Flood levels will generally be higher upstream of the weir and lower immediately after the weir. If a weir falls into disrepair or is removed, flood levels become more consistent on the stretch of watercourse, which could lead to increased flood risk immediately downstream of the weir. If a weir were to become blocked or raised due to an accumulation of debris this could lead to higher water levels upstream and an increased flood risk. Flap valves are designed for use on the discharge end of pipes to prevent backflow or intrusion into the pipe. Typical applications include discharges to rivers, reservoirs, ponding basins and standpipes. Failure of a flap valves only tends to be an issue if they are located at sites protected by natural high ground or raised man made defences. Surcharged flow in the river could cause backflow through the pipe and flooding from manholes behind the defences or raised areas. There are a number of outfalls, weirs and culverts within the study area. Many of the assets are located along the rural areas of the rivers, or adjacent to industrial estates. Many of the rivers are rural in nature. Watercourses that are allowed to flow in their natural floodplains in times of flood and are allowed to follow their natural course are generally less problematic than urban watercourses. Where there are culverts, outfalls and weirs, in the more rural areas the impacts from blockages and flooding will tend to be small.

The known existing assets in the study area can be seen in the drawings in Appendix D. This includes culverts, outfalls, weirs, flap valve, penstocks, sluices, and gabions. These assets should be regularly maintained and, if needed, upgraded in order to prevent localised flooding.

6.5.1 Assets in Chesterfield 6.5.1.1 Outfalls and Flap Valves Throughout Chesterfield there are a number of outfalls, predominantly associated with the River Rother, River Drone and River Doe Lea. Outfalls into rivers are generally fitted with a flap valve if it is likely to become surcharged during periods of high river flows. Flapped outfalls can become damaged or blocked and stay open allowing water from the river to back up the system. Another potential risk is for the flap valves to seize shut (e.g. due to rust) causing flow to back up behind the valve. Both these mechanisms have the potential to cause flooding and it is important that all major outfalls are maintained regularly.

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One location in particular which should be considered is St Augustines. Location of outfalls and flap valves are shown on the asset drawings in Appendix D. 6.5.1.2 Culverts Installing new culverts on watercourses is to be avoided where possible. Installing a culvert will limit the capacity of water which can flow along the channel as it creates a finite area for the water to occupy. Culverts can cause afflux, which is a raised water level upstream of the entrance to the culvert. Also, there are maintenance issues to consider such as a blockage or collapse. The River Hipper is shown to be culverted in a number of sections upstream of the confluence with the River Rother, which are included in the hydraulic model. The model shows there are two culverts at Brampton (Factory Street and Dock Walk) one of which causes a backwater effect in extreme flood conditions, and the other is surcharged during the 5-year storm and completely overtopped for storm with return periods greater than 1 In 75 years. 6.5.2 Assets in Bolsover There are three sluices on the River Doe Lea in the western area of Bolsover. Sluices could cause or exacerbate flood risk due to untimely or inappropriate operation or failure to close during a flood. The majority of assets in Bolsover are along the rural reaches of the watercourses and, as such, the consequence of failure is low.

The only known assets within the Bolsover area are along the rural reaches of the River Doe Lea and Normanton Brook. The consequence of increased flooding due to these assets is low.

6.5.3 Assets in North East Derbyshire There are few weirs along the River Drone and The Moss. Most of these are adjacent to either low vulnerability industrial properties or to rural areas and, as such, the consequence of failure is fairly low. There are a number of outfalls along the River Drone, and the River Rother. Some of them are along their rural reaches, while others are next to residential areas, such as upstream of the railway bridge, Chesterfield Road, Dronfield. For the location of weirs, refer to the asset plans in Appendix D. The River Drone is also shown to be culverted for a long section along Sheffield Road to Soaper Lane, Dronfield. The area upstream of this culvert is likely to be at a higher risk of fluvial flooding. Regular inspection and maintenance of this culvert should be carried out.

The known assets within the NEDDC are along the River Drone and the River Rother. Parts of the assets along the River Drone are near residential developments, in Dronfield. These assets should be regularly maintained and, if needed, upgraded in order to prevent localised flooding.

6.6 Flood risk from reservoirs The allocation matrix includes results for sites located close to reservoirs (see Appendix B).

Reservoirs in the catchment are used to store water for various uses such as water supply, recreation or flood storage. Flood control reservoirs alleviate flooding by attenuating the peak fluvial flows and releasing flow downstream in a controlled manner. Safe operation and management of reservoirs is required to manage the associated flood risk. A dam failure could have major consequences, including loss of life. Reservoirs impounding over 25,000m 3 of water fall under the Reservoirs Act 1975. Under this Act, reservoir owners (Undertakers) have ultimate responsibility for the safety of the reservoir. They must appoint a Panel Engineer (a specialist civil engineer who is qualified and experienced in reservoir safety) to continuously supervise the reservoir and to carry out periodic

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inspections. For large reservoirs covered by the Act, the consequences of failure would be very high; however, the likelihood of failure would be very low and, as such, the overall risk is generally low. Reservoirs (or other impounded bodies of water) with storage of capacities less than 25,000m 3 can still pose a significant hazard if failure were to occur. As these bodies of water are not covered by the Reservoirs Act and are less likely to undergo routine inspection and maintenance, they can present a higher flood risk due to a higher likelihood of failure. Developments within the potential area of risk should consider the reservoir in detail. Generally, if the reservoir is covered by the Act, breach assessment would not normally be required. However, development within the potential destruction zone could increase the number of people who would be at risk and, as such, the volume of people who may need to be evacuated in an emergency. The Emergency Planning department of the council should be consulted to ensure that new development in these locations would not put an unacceptable burden on the department and can be accommodated by the existing evacuation procedures. Operation of smaller reservoirs (or other bodies of water) may have to be considered in more detail to ensure new and existing developments are not at an unacceptable risk, which could include hydraulic modelling and breach assessment. Poor maintenance of private and abandoned reservoirs could also cause sedimentation to occur. The accumulation of sediments in reservoirs can lead to a range of problems, including:

 Increased flood risk on influent streams due to raised bed levels in the reservoir;  Loss of flood storage capacity causing increased spillway flows;  Blockage of scour pipe affecting the ability to drain the reservoir in an emergency;  Build up of sediment against the upstream face of the dam, adversely affecting the stability of the structure.

The consequences of failure of large reservoirs (more the 25,000m 3 of water) would be very high; however, the likelihood would be very low. Hydraulic modelling and breach analysis may be required for private and abandoned reservoirs. Future maintenance of small reservoirs (and other impounded bodies of water) should be given serious consideration.

6.6.1 Reservoirs in Chesterfield There are a number of reservoirs within Chesterfield but it is not known which are officially covered by the Reservoirs Act 1975. It would appear that the majority are private due to their small plan areas. All of the known existing reservoirs in the study area can be seen on the asset drawings in Appendix D. Locations which should be given particular attention are as follows:

 Brampton – Walton Dam  Staveley/Poolsbrook. Other reservoirs within the District appear to be low-lying and, as such, the flood risk is considered to be low. 6.6.2 Reservoirs in Bolsover Specific information on the location of reservoirs in the catchment was not provided by the council. However, the colour OS maps have been reviewed to determine the location of the reservoirs within the district. It is unknown which are covered by the Reservoirs Act. Privately owned Harlesthorpe Dam, in Clowne is a known source of flood risk to properties, on Creswell Road and Station Rd. Also, fields downstream of the dam, adjacent to the watercourse, have a history of being waterlogged. 6.6.3 Reservoirs in North East Derbyshire There are numerous reservoirs within the District and the following appear large enough to be covered by the Reservoirs Act 1975.

 Brampton – Upper, Middle and Lower Linacre  Ogston – Ogston Reservoir  Northedge – Press Reservoirs  Wingerworth – Wingerworth Lido

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There are various other reservoirs and impounded bodies of water which may need a more detailed assessment. Locations which should be given particular attention are as follows:

 Holymoorside – Old Mill Pond  Ford Fishing Pond 6.7 Mitigation for Flood Zones Mitigation of flood risk should be the final consideration for development (see Table 1.2 of PPS25 practical guide). Prior to determining what type of mitigation which may be required, consideration should be given to the following:

 Avoidance/prevention - Allocate developments to areas of least flood risk and apportion development types vulnerable to the impact of flooding to areas of least risk. Then,  Substitution - Substitute less vulnerable development types for those incompatible with the degree of flood risk. Then,  Control - Implement measures to reduce flood frequency to existing developments. Appropriate design of new developments. And finally,  Mitigation - Implement measures to mitigate residual risks. Mitigation measures could include the following:

 Flood resistance techniques (preventing ingress of water);  Flood resilience measures (allowing water to enter properties but designing to minimise damage caused);  Implementation of Emergency Planning Documents, flood warnings and evacuation procedures. Flood resistance techniques could include improvements to existing flood defences, land raising, non habitable ground floors, and secondary defences such as flood storage and drainage improvements. This section aims to advise on the mitigation measures to be considered in each Flood Zone to ensure the development is appropriate. This does not override what is stated in PPS25 regarding appropriate development in Flood Zones, nor does this override the Sequential and Exception Tests and the other flood risk management options stated above. 6.7.1 Flood Zone 3b Development within this Flood Zone should be avoided all together if possible. Only water- compatible uses and essential infrastructure would be appropriate. Should this type of development go ahead it should be constructed to:

 remain operational and safe for users in times of flood;  result in no net loss of floodplain storage;  not impede water flows; and  not increase flood risk elsewhere. 6.7.2 Flood Zone 3a Water-compatible, essential infrastructure and less vulnerable uses of land may be appropriate in this Flood Zone. More vulnerable or highly vulnerable uses should only be permitted if they pass the exception test. Development behind defences should only take place if the defences are constructed to the required SoP and are in a good condition. The Environment Agency’s NFCDD provides this information and has been used for this report. However, the information on the NFCDD is not exhaustive. The requirement is to provide protection up to the 1 in 100 year fluvial event. If possible, developments should be set back from defences, outside of the flood envelope or breach envelope. Development within the flood envelope behind defences should have finish floor levels above the 1 in 100 year fluvial flood or breach level. Sufficient freeboard, to take into account climate change and modelling uncertainties should be added onto this level. It is generally accepted that finished floor levels should be set at 300mm above the 100 year plus climate change level or 600mm above the 100 year flood level. If no flood level information is available, 600mm above surrounding ground levels may be acceptable but, in most cases, hydraulic modelling will be required to confirm the predicted flood levels.

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Undefended areas should also have finished floor levels set above the 1 in 100 year fluvial flood level with sufficient freeboard to take account of climate change.

Land raising must be accompanied by compensatory provision or flood storage either on or off site. Even when the development is behind defences flood compensation storage may be required for land raising if secondary flooding (e.g. flooding from flood locked rivers) is possible.

Where possible, consideration should be given to making the ground floor uninhabitable by designing ground floor car parking or putting other public areas here.

For defended areas in particular, the focus should be on safety to residents from residual risk (e.g. breach of a flood defence). However, all development should consider safe access and egress in times of flood. Flood risk that threatens public safety and the structural integrity of buildings should not be considered.

6.7.3 Flood Zone 2 Water-compatible, less vulnerable and more vulnerable uses of land and essential infrastructure may be appropriate in this Flood Zone. If development does take place in this Flood Zone, finished floor levels should be set above the 1 in 100 fluvial flood levels. Again, an appropriate freeboard allowance should be added to take into account climate change and modelling uncertainties. 6.7.4 Flood Zone 1 All types of development should be appropriate in this Flood Zone. The predominant flood risk issues relating to sites in Flood Zone 1 will be other forms of flooding and surface water run-off from the site. 6.7.5 Flood Resistance and Flood Resilience The companion guide to PPS25 states that, in all flood risk areas, a basic level of flood resistance and resilience should be considered to limit the impact of a flood event. Flood resistant and resilience measures can be described as:

 Flood resistance, or ‘dry proofing’, where flood water is prevented from entering the building. For example using flood barriers across doorways and airbricks, or raising floor levels.  Flood resilience, or ‘wet proofing’, accepts that flood water will enter the building and allows for this situation through careful internal design for example raising electrical sockets and fitting tiled floors. The finishes and services are such that the building can quickly be returned to use after the flood. Examples of both flood-resistant and flood resilient designs are given in “Flood resilient and resistant construction – guidance for new build” (CLG/Defra/EA, May 2007: Improving the flood performance of new buildings: Flood Resilient Construction) Available from www.communities.gov.uk . 6.7.6 Surface water mitigation The surface water disposal for new developments should be managed in a way that does not increase flood risk for downstream properties. No flooding should occur for rainfall events with return periods of 1 in 30 years or less. For events with a return-period in excess of 1 in 30 years, surface flooding of open spaces such as landscaped areas or car parks is acceptable for short periods, but the layout and landscaping of the site should aim to route water away from any vulnerable property. No flooding of property should occur as a result of a 1 in 100 year storm event (including an appropriate allowance for climate change). The developed rate of run-off into a watercourse, or other receiving water body, should be no greater than the existing rate of run-off for the same event (including an allowance for climate change). Volume of run-off should be reduced where possible using infiltration techniques or a reduction in impermeable area.

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Section 5.18 to 5.51 of the companion guide to PPS25 and Appendix A3 in ‘CIRIA RP624 Development and flood risk – guidance for the construction industry’ provides more details and practical examples of flood risk mitigation measures. 6.8 Existing Defences below the Required Standard of Protection Ideally, developed urban areas behind flood defences should be protected against a 1 in 100 year fluvial flood. PPS25 Annex G section G2 states that ‘development should not normally be permitted where flood defences, properly maintained and in combination with agreed warning and evacuation arrangements, would not provide an acceptable standard of safety taking into account climate change’.

Generally, defences in the catchment are not to a SoP of 1 in 100 years.

Development in Chesterfield, Bolsover and North East Derbyshire

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7 Development in Chesterfield, Bolsover and North East Derbyshire

7.1 Summary of Regional Flood Risk Assessment The tables below show some figures produced in preparation for the regional flood risk assessment (RFRA) for the . This was carried out by Faber Maunsell in July 2006 using proposed housing forecasts according to the Draft Regional Spatial Strategy (RSS). This provides a general assessment of the number of properties at risk and the ranked risk for the LPAs in the East Midlands. The assessment also attempts to assess potential future flood risk from housing provision and development pressure. The work undertaken that produced these figures will form the basis of the East Midlands Regional Assembly’s (EMRA’s) RFRA as required by PPS25. In doing this it will assist the Regional Assembly and LPAs in assessing the feasibility and implications for future flood risk of current planned residential development sites in emerging RSS and LDFs. A two part Flood Risk Profile (FRP) was developed, considering both ‘”inherent” and “actual” flood risk in each LPA area. Part 1 of the Profile identified the percentage of land in Zone 3 and LPAs were placed in one of four Groups (A, B, C or D) according to the percentage of Zone 3 land in their area. The LPA’s perception of the significance of flood risk as a factor to be considered in development planning was ranked on a scale from 1 to 10, with 10 being very important. Part 2 of the profile identified the level of “actual” risk in the LPA’s area by considering relative levels of flood risk from primary, secondary and residual risk sources. For each of these factors, both probability and consequences of flooding were taken into account. Risk levels were identified as High, Medium or Low. To supplement the percentage classification, the score allocated by the LPA to indicate their perception of the significance of flood risk in the making of strategic planning decisions, has been added. See Table 13 below for details. Table 13: Percentage of properties that are in Flood Zone 3 % of props in District Band Significance Flood Zone 3 Chesterfield less than 10% A 4 - medium significance Bolsover less than 10% A 2 - low significance North East less than 10% A 5 - medium significance Derbyshire

Two essential elements of flood risk, i.e. probability and consequence, have been considered for the primary source of flooding (i.e. rivers) and within each LPA area the locations and types of flood defences have been identified. Probability has been assessed as being high, medium or low, according to the following criteria:

 High If none (or very few) of the flood defences currently meet the target standards.  Medium If flood defence standards are variable – a mixture of high and low.  Low If all (or most) of the flood defences currently meet the target standards. Consequence has been assessed as being high, medium or low, according to the following criteria:

 High If flooding from Primary Sources would impact on dense urban areas.  Medium If flooding from Primary Sources would impact on semi-urban, scattered developments.  Low If flooding from Primary Sources would impact on rural areas (undeveloped land). Table 14 makes an assessment (based on the RFRA) of whether each LPA area is not protected to the required standard by existing flood defences. Typical target standards of protection for urban developments against flooding from river flooding are 1 in 100 years.

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Table 14: LPA areas benefiting from defences District Probability Consequence

Chesterfield M M Bolsover L L North East L L Derbyshire

Secondary sources of flooding have also been considered. Similar criteria for probability and consequences were used as for primary sources. Secondary sources of flooding have been taken to be arterial drainage systems operated by IDBs, and surface water sewers maintained by Severn Trent Water. However, because IDB systems usually have adequate capacity and water companies were (at the time) required to accept surface water flows from development, neither the probability nor the consequences of flooding from secondary sources are likely to be high (relative to those from primary sources). It should be noted that this may change in the future as water companies may no longer be obliged to accept like for like surface water flows. Taking this into account, only one indicator has been used to illustrate flood risk from secondary sources:- M – where probability or consequences is medium L – where both probability and consequences are low Table 15: LPA areas at risk from secondary sources of flooding District Probability Chesterfield L Bolsover L North East L Derbyshire

Residual risk for each LPA area has been assessed (see Table 16). Residual risk of flooding is the risk which remains after flood defences have been provided. By their very nature, residual risks generally have a low probability of occurrence. However, consequences can vary from low (e.g. marginal overtopping of a flood defence wall), to high (e.g. sudden collapse of a high flood defence bank – where property is located close by). One indicator has been used to illustrate the possible consequences of residual risk, i.e. either H, M or L, depending on the extent and height of flood defences in the locality and the density and proximity of development relative to the defences. Table 16: LPA Areas Residual Risk District Probability Chesterfield M Bolsover L North East L Derbyshire

Table 17 combines Tables 13, 14, 15 and 16 in an effort to show the full Flood Risk Profile, for each LPA area.

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Table 17: Flood Risk Profile Inherent District Significance Actual Risk Risk Primary Secondary Residual Probability Consequence CBC A 4 M M L M BDC A 2 L L L L North East A 5 L L L L Derbyshire

7.2 Chesterfield, Bolsover and NE Derbyshire Area 7.2.1 Chesterfield From the RFRA figures it could be concluded that Chesterfield has an average to low level of flood risk. Table 17 shows that less than 10% of Chesterfield falls within Flood Zone 3, while the significance of the flood risk is medium. Chesterfield need to be able to identify appropriate mitigation measures for future developments as medium to high level risks exist from primary sources of flooding. Residual risks in some areas are medium as main rivers pass through semi- urban areas. The overall flood risk to Chesterfield is classed as medium. These figures are not a good predictor of the future and should be treated with caution. Chesterfield has a large green belt area which constrains where new development can currently take place. There is therefore much more development pressure in Chesterfield than is perceived by these figures. Chesterfield has a potentially significant source of flood risk in the River Rother. 7.2.2 Bolsover Bolsover has a low level of flood risk. Less than 10% of Bolsover falls within Flood Zone 3, and residual risks are relatively low. The overall flood risk to Bolsover is classed as low. 7.2.3 North East Derbyshire NE Derbyshire appears to have a more than 10% of land in Zone 3 (21% - 50%), and the significance of flood risk as rated by the LPAs is medium. The residual flood risk and the risk from secondary sources of flooding are low.

These figures do not take into account flood risk from other sources, just the Flood Zone maps, land drainage and flooding from surface water sewers. Flood risk in Chesterfield, Bolsover, and NE Derbyshire comes from a number of sources including groundwater flooding, artificial sources, and failure of assets. These tend to be sporadic in nature and can occur at a higher return period than river flooding.

7.2.4 Current Major Development Projects 7.2.4.1 Chesterfield Major employment opportunities have been identified in south east of Staveley at Markham Vale (EMP1). Outline planning permission was issued in April 2005, and it is anticipated that the project will be completed over a period of 10 years (from when permission was granted). The total employment land at Markham Vale is 64.6 ha. Structural plan provision for employment land is concentrated on class B uses, comprising office, business and light industry (B1), general industry (B2) and distribution (B8). The majority of this area is located in Flood Zone 1 and should be suitable for all types of development. Further employment land has been allocated in the 2006 Replacement Chesterfield Borough Local Plan (EMP7) in the business districts of Staveley and along the A61 corridoor (GEN11). Sites for employment development in the long term have also been identified as Troughbrook works and North Brimington (EMP6). Significant parts of these development sites are located in Flood Zones 2 and 3 and would require detailed flood risk assessments to be carried out.

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Planning permission has recently been granted for a large tourism development near Unstone Green area (EMP11) (development in Chesterfield Borough Council, nearby village in North East Derbyshire District Council). This site is located in Flood Zone 1 and should be suitable for the proposed development. Chesterfield Borough Council is currently leading a redevelopment scheme within the Town Centre Northern Gateway and to the south of Chatsworth Road in the A619 corridor (GEN13). The majority of the site is located in Flood Zone 1 but some areas fall within Flood Zone 2. The development site should be made sequentially appropriate by placing lower vulnerability uses (such as public open space) in the high risk Flood Zones (see section 8.3 for more information). At this location there are two major proposed residential developments (HSN1/H38a & HSN1/H38b) located predominantly in Flood Zone 3. It is essential that the sequential approach is considered during the design to direct development away from low-lying areas if possible. Planning permission has been granted for the development of a 9,755 sq.m DIY retail store on land at Derby Road, together with 2,325 sq.m of builders centre and 1,860 sq.m of garden centre (SHC5). Part of the development is within Flood Zone 3a and 3b. There appear to be numerous sites for both housing and employment located in Flood Zone 1 and these should be brought forward prior to sites at a higher risk of fluvial flooding. 7.2.4.2 Bolsover There are numerous sites that have been identified as having potential for either residential or employment or a mixture of both. The majority of these sites are located in Flood Zone 1 and should be suitable for development. Some however fall in Flood Zone 2 or 3, for example: One site of potential concern is located adjacent to Station Road, Clowne (172) which falls partially in Flood Zone 3a. Also of concern is the Oxcroft Coal Disposal Point Site (226). Parts of this site are located in Flood Zone 3 and any development should be sequentially appropriate. The Coalite Site (218 and 219) within Bolsover is considered to be suitable for employment development and part of it falls Flood Zone 3a adjacent to the Doe Lea. Sequential approach should be applied by placing lower vulnerability uses in the high risk Flood Zones (see section 8.3 for more information). Employment site 207 is located partially in Flood Zone 3a. A detailed flood risk assessment should accompany the development within Flood Zone 3, which should consider the sequential approach (see section 8.3 for more information). 7.2.4.3 North East Derbyshire There are sites within the district which are already in employment use. For these sites according to the policy E6 either new employment development or extensions to existing premises will be permitted in cases where they would not lead to unacceptable environmental problems. Sites E6 a), c), d), e), f) and k) are shown to be located within the indicative 1 in 100 year flood plain. There are small residential sites which already have planning permission and are shown to lie within the 1 in 100 year floodplain. It is proposed to replace a school at Unstone. Part of this site is located in Flood Zone 3 and, as such, any redevelopment should be sequentially appropriate. 7.2.5 Potential Future Development Sites Potential future development sites have been suggested by the LPAs. These sites have come from a number of sources including the local development plans. Each site has a reference number indicating the potential future development sites in Appendix B and the development site drawings in Appendix D. The Adopted East Midlands Regional Spatial Strategy (RSS8) states that the Local Authorities should employ policies and select sites in order to achieve a target of 60% of additional dwellings on previously developed land at the Regional level by 2021.

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7.2.5.1 Chesterfield Major employment opportunities have been identified within the Town Centre Northern Gateway and to the south of Chatsworth Road in the A619 corridor. Within Chesterfield, potential future development sites are fairly concentrated. According to the local plan, Chesterfield should provide 214 dwellings each year between 2011 and 2026. A sufficient supply of housing sites must be identified to meet a regional housing allocation for the district of 9,000 dwellings from 2006 to 2026. The national target of 60% housing completions on previously-developed land has already been exceeded in the borough and is approaching 100%. 7.2.5.2 Bolsover The Preferred Options stage of the Site Specific and Area Based allocation development Plan Document was prepared by Bolsover District Council in 2006, which includes site specific proposals to deliver the policy framework set out in the Core Strategy Preferred Options.. According to the Site Allocations document a sufficient supply of housing sites must be identified to meet a regional housing allocation for the district of 7,449 dwellings from 2006 to 2026. The Bolsover Employment Land Study (2006) identifies 481 ha of existing employment land in the district; however not all of this land meets the needs of the district either because it is poor quality or is not economically attractive. Analysis of the sites has identified 20.9 ha of existing land or land currently allocated in the Adopted Local Plan that could be reused for other uses. 7.2.5.3 North East Derbyshire The Derby and Derbyshire Joint Structure Plan sets out a requirement for 4300 dwellings to be provided within North East Derbyshire between 1991 and 2011. At 31 March 2005, 3262 dwellings had been completed in the District since 1991. The Urban Capacity Study identifies potential development sites to accommodate approximately 353 dwellings in the Chesterfield area (sub-area within NEDDC. In terms of housing requirements the house divided into three Structure Plan Sub Areas.) Those brownfield sites with a capacity for 10 or more dwellings form allocations, accommodating a total of approximately 209 dwellings. Within NE Derbyshire, provision should be made for 125 ha of land for general industrial, business use and distribution development in the 1991-2011 period. This represents an annual completion of 6.25 ha for the district. 7.2.6 Use of the SFRA for LDF potential development sites Planning Policy Statement 3: Housing requires that the LPA undertake a Strategic Housing Land Availability Assessment (SHLAA) to support the delivery of sufficient land to meet the community’s need for more homes. The purpose of the assessment is to evaluate the existing supply of housing, identify sites with potential for housing, assess their housing potential and assess the likelihood of those sites coming forward for development. It is a key part of the evidence base for the LPA's LDF. There are a number of small and large developments within the three Districts, some of which are located on greenfield land and some cover major industrial units. The SFRA should be used to sequentially assess sites in the CBC’s, BDC’s and NEDDC’s Draft SHLAA, following a similar format to the sites already assessed in Appendix C. The SFRA provides a consistent methodology for assessing any new potential development sites submitted to the LPA. The assessment of these sites will also follow the guidance in the SFRA and the format of Appendix B. For both the SHLAA and potential development sites, flood risk is an important consideration in determining the allocation of sites for new development. However, the LPA will be required to balance this against other environmental, social and economic factors and planning constraints. For any sites that are considered for allocation contrary to the SFRA, appropriate mitigation measures should be provided.

Assessment of Flood Risk in Study Areas

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8 Assessment of Flood Risk in Study Areas

PPS25 requires that LPAs prepare SFRAs to an appropriate level of detail to allow the Sequential Test to be applied in the site allocation process. SFRAs should refine information on the probability of flooding, taking other sources of flooding and the impacts of climate change into account. This SFRA has gathered flood risk information in order to complete an initial Sequential Test for future development sites being considered by the LPAs, as at May 2008. The SFRA provides enough information to allow the Sequential Test to be completed for any other sites that are to be brought forward for consideration in the future. The SFRA also identifies areas at risk of flooding from sources other than rivers and identify any flood risk management measures, including infrastructure and the coverage of flood warning systems. Guidance on the preparation of FRAs for future development sites and guidance on the likely applicability of different sustainable drainage systems (SuDS) techniques for managing surface water run-off at key development sites will also be included. The majority of this information for the different sites is contained in the matrix which is in addendum of this report. 8.1 The Sequential Test Existing undeveloped Local Plan allocations, sites with planning permission and strategic sites have been provided by the LPAs. The aim of the Sequential Test is to direct development away from areas at risk of flooding.

Development should be directed to Flood Zone 1 wherever possible, and then sequentially to Flood Zones 2 and 3, and to the areas of least flood risk within Flood Zones 2 and 3, as identified by the SFRA (see Table D.1 and Table D.2 of PPS25).

The Flood Zone maps show current best estimates of the risk of flooding from rivers and does not consider other sources. Therefore this principle of locating development in lower risk areas should be applied to other forms of flooding. Judgement can be used to identify those areas in which flood risk from other sources of flooding is likely to be higher. The sequential approach can then be applied to steer new development away from these higher risk areas.

Once the Sequential Test has been completed the following should be considered:

 Development in Flood Zone 3 should be seen as a last resort and certain uses (as identified in PPS25 Table D1) are inappropriate in high risk areas and should not be permitted at all.  Development in Flood Zone 2 should not be seen as without risk of flooding.  Appropriate measures to manage residual risk must be applied to any developments which are exceptionally constructed in flood risk areas. These measures must take into account effects of climate change.

8.1.1 Functional floodplain Flood Zone 3b PPS25 defines a Functional Floodplain as land where water has to flow or be stored in times of flood. Specifically, this land:

 would flood with an annual probability of 1 in 20 (5%) or greater in any year, or at another probability to be agreed between the LPA and the Environment Agency (EA), or:  is designed to flood in an extreme (0.1%) flood, or at another probability to be agreed between the LPA and the EA. The functional floodplain relates only to river and coastal flooding and does not include areas at risk of flooding solely from other sources of flooding (e.g. surface water, sewers). The functional

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floodplain (Zone 3b) is determined considering the effects of defences and other flood risk management infrastructure (i.e. if there is a defence in place there is no functional floodplain).

Flood Zone 3b (functional floodplain) is the highest risk zone and effort should be made to steer development (apart from water compatible) away from this zone. The Practice Guide Companion to PPS25 gives further guidance on the definition of Flood Zone 3b and allows flexibility to subjective interpretation. More specifically it states that areas, which would be subject to flooding in the 5% (1 in 20 year) annual exceedence probability flood event but where the flow of flood water is prevented by existing infrastructure or by solid buildings or other solid barriers, will not be normally defined as Flood Zone 3b.

Modelled data is available for the Rivers Rother, Hipper and Doe Lea. Tidal flooding is not an issue in the area. The modelled flood extents for the 1 in 100 year and 1 in 100 year plus climate change events do not match the extents on the EA flood maps. Flood Zone 3b (Functional Flood Plain) has been produced for these modelled reaches (only in Chesterfield) where there are no defences. 8.2 Application of the Sequential Test In “A Practical Guide Companion to PPS25” (February 2007) a flow chart is provided which shows how to apply the Sequential Test (see Figure 7) within the LDF process. This has been used as a basis to the application of the Sequential Test for the SFRA. The data provided by the LPA (Appendix B) were brought into a GIS mapping system, displaying background OS maps and the Environment Agency’s Flood Zones. In addition, information on other sources of flood risk including canals, ordinary watercourses and reservoirs were brought into the mapping as well as climate change flood maps. This allowed the filtering out of sites (received by April 2008) that are not thought to be directly at risk of flooding now and in the future (due to climate change). For these sites recommendations have been provided based on the size of the development site (see the addendum of the report). These recommendations include the need to consider surface water disposal and the implementation of SuDS. These sites have remained as point data but are still included in the flood risk matrix and potential future development sites database. For the remaining potential development sites that were at risk of flooding, a more detailed approach was taken in order to identify the sites most at risk of flooding. This was completed using the GIS mapping and inputting the data into the flood risk matrix. 8.3 The Sequential Approach The sequential approach should be carried out for sites located in areas at risk of flooding. The process aims to ensure that the parts of the site at least risk of flooding are developed in preference to the parts at higher risk. Developers should make the most appropriate use of land to minimise flood risk, substituting land uses so that the most vulnerable development is located in the parts at lowest risk. They should also make the most of opportunities to reduce flood risk, e.g. creating flood storage and flood pathways when looking at large-scale developments. The sequential approach should also be used at the regional level to identify broad areas for future development that avoid flood risk.

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Figure 7: Application of the Sequential Test (taken from PPS25)

Notes 1 Flood Zone 1 for fluvial and tidal flooding and with a low risk of flooding from other sources. 2 Flood Zone 2 for fluvial and tidal flooding and with a medium risk of flooding from other sources. 3 As defined by the Sequential Test. 4 Development to be safe and to not increase flood risk elsewhere. Required to pass part c) of the Exception Test, where applicable. 5 Including susceptibility to future climate change and residual flood risk.

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8.4 Flood risk matrix explanation

A flood risk matrix has been produced to identify the highest risk potential future development allocations and summarise recommendations. This can be found in the Addendum of this SFRA.

The matrix is made up of a list of sites down the first column and data inputs across the first row. The first few columns of the matrix are concerned with the potential development sites i.e. name, size, status. The next column identifies the Flood Zone in which the site is located. If the site is affected by different Flood Zones then this is shown. Different recommendations will apply to different parts of the site.

For sites affected by multiple Flood Zones, the LPA should direct less vulnerable types of development towards the less vulnerable parts of the sites (taking into account flood hazard and the different flood extents).

The next column identifies what is the standard of protection of defences adjacent to the potential development site. This can also be applied to the river channel without defences, for example canalised sections of the River Rother will have a higher SoP than a natural river because it has been deepened and walled. These sections however are not classed as official raised defences. By including this column we can identify which potential future development sites are served by flood defences and whether the indicative SoP is met. If defences are not protected from up to the 1 in 100 year fluvial flood then the SoP has not been met. Recommendations can then be made for improving the SoP of defences if there is a pressing need for development to take place here. Alternatively compensatory flood storage can be integrated into the design of new developments. The flood risk profile column looks at the level of risk within a Flood Zone. This is based on flood velocity, depth and distance from defences (an explanation can be seen in section 6.2). This column allows us to distinguish higher risk locations within a Flood Zone. The historical flooding column contains information provided by the councils, Severn Trent Water, Yorkshire Water and the EA regarding locations of historical flooding. The assets column shows the presence of assets that could result in flooding. This would include culverts, outfalls, reservoirs, dams, weirs, flap valves, sluices etc. The ‘other influences’ column provides details on other possible sources of flood risk, whether the defence SoP is met, if the site has been flooded in the past or is within a historic flood outline and whether the site is brownfield. These details allow an assessment of whether the site is more at risk from other sources compared to other sites. Also if a site is greenfield, not defended to a high enough standard or has a history of flooding, these sites can be put below other sites in terms of acceptability for development. The ‘current development site’ column shows what the response to the current development site should be, according to PPS25. In the recommendations column a brief recommendation is made, for more details on what is required for the development site, Table 18 and Figure 8 should be used (see Sections 8.6 and 8.7) After each site there is a colour coding. This is based on the level of flood hazard and what Flood Zone the site is in. It should be possible, using the colour code key, to identify where the highest risk and lower risk potential future development sites are (or parts of sites). The “Flood Levels” column indicates whether there is modelled or actual flood data available. The “Comments” column provides a commentary regarding adjacent sites, where climate change may affect the site, or if there is some other extreme situation.

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A summary of the Addendum is provided below but specific analysis (directing more vulnerable development away from high flood vulnerable sites) should be undertaken in more detail when producing the DPDs.

8.5 General summary Within the development and flood risk matrix each site has been assessed according to its specific issues. The site has been split in line with which Flood Zone parts fall within it. This has then been colour coded. The key to the colour code can be seen on the matrix. The LPA should aim to divert development away from higher risk Flood Zones and the higher hazard ratings when planning what type of development should go where. A summary of the findings can be found below. 8.5.1 Chesterfield Flood risk is a significant issue for regeneration in Chesterfield. Historically strong links have existed between industrial development in Chesterfield and the main watercourses, to provide power and material for processes, and in some cases transportation. Major structural change in the manufacturing industry has seen many of these industrial areas run down or closed, leaving Chesterfield with a legacy of former industrial sites in the urban area in need of regeneration, clustered along the river corridors on land affected by historic or potential flooding. Given the previous history of many of these sites in heavy industrial use, forms of regeneration capable of providing remediation need to be sought. They also provide a rich stock of brownfield development land, often sustainably located close to existing urban centres, activities and transport facilities. Chesterfield Borough Council has sought to take a comprehensive, masterplanned approach to a number of these key sites, recognising the difficulties involved alongside their potential. These include:

 The A61 Corridor, former industrial land alongside the River Rother and Chesterfield Canal;  Land South of Chatsworth Road, a complex of former mills and other industrial and commercial uses alongside the River Hipper;  Staveley Works, a corridor of former chemical works, foundries and pipeworks along the route of the River Rother and Chesterfield Canal. All of these sites contain areas within Flood Zones 2 and 3, which present significant challenges to their regeneration. 8.5.2 Bolsover Bolsover district is situated in the North Derbyshire Coalfields area of the East Midlands, which extends between and the Peak District National Park. The district shares its northern boundaries with South Yorkshire. The 2001 Census recorded a population of 71,766 people. A significant proportion of this population is focused within the four towns of Bolsover, Shirebrook, Clowne and South Normanton. The expansion of settlements is constrained by settlement framework boundaries. The eastern part of the district lies predominantly on an outcrop of magnesian limestone whose fertile soils give rise to the largest tract of high-grade agricultural land in Derbyshire. It is likely that the district will need to provide between 350 – 400 dwellings per year, although the final Regional Plan figure is yet to be announced. The sub regional employment land study recommends that the range of estimated demand could be between 165 and 220 hectares . The M1 bisects the district and there is considerable development pressure around junctions 28 and 30, particularly for employment. 8.5.3 NE Derbyshire North East Derbyshire District lies on the edge of the Peak District National Park and surrounds Chesterfield District to the north, west and south. It covers an area of about 258 square kilometres and has a population of almost 100,000 people. With Sheffield and Rotherham lying to the north, the District is under considerable pressure for development. All settlements are constrained by Settlement Development Limits to ensure the protection of the surrounding countryside. The centres of population in the north of the District - Dronfield, Eckington and Killamarsh are constrained by the Green Belt, the purpose of which is to prevent the coalescence of Sheffield and Chesterfield. Clay Cross, together with the smaller settlements of

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North Wingfield and Wingerworth, lie further to the south. The rest of the District is predominantly rural and much of it is Special Landscape Area. The eastern part of the District, in particular, is undergoing regeneration and structural change following the decline of the coal mining industry. The emerging East Midlands Regional Plan expects the District to provide land for about 330 new houses each year between 2001 and 2026. 8.6 General requirements for planning applications Table 188 below can be used as a guide when considering a site brought forward for development through planning applications. This can be used as a checklist and should ensure all factors relating to flooding, drainage and development near to watercourses are taken into account at an early stage. Table 18: General responses for all proposed developments Development issue General statements/requirements All development proposals in this zone should be accompanied by a FRA, See Annex E of PPS25 for minimum requirements.

Only the water-compatible uses and the essential infrastructure listed in Table D.2 of PPS25 that has to be there should be permitted in this zone.

Proposed developments within Flood Refer to the SFRA (if site included) and refer to the Zone 3b site specific guidance. If not included, consider the sequential test requirements/ windfall sites, and general issues described.

Use findings from SFRA to consider vulnerability and risk to people and property.

The Environment Agency must be consulted.

All development proposals in this zone should be accompanied by a FRA, See Annex E of PPS25 for minimum requirements.

The water-compatible and less vulnerable uses of land in Table D.2 of PPS25 are appropriate in this zone.

Proposed developments within Flood Refer to the SFRA (if site included) and refer to the Zone 3a site specific guidance. If not included, consider the sequential test requirements/ windfall sites, and general issues described.

Use findings from SFRA to consider vulnerability and risk to people and property.

The Environment Agency must be consulted.

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Development issue General statements/requirements All development proposals in this zone should be accompanied by a FRA, See Annex E of PPS25 for minimum requirements.

The water-compatible, less vulnerable and more vulnerable uses of land and essential infrastructure in Table D.2 of PPS25 are appropriate in this zone.

Proposed developments within Flood Refer to site specific guidance in the SFRA Zones 2 development site matrix. If not included, consider the sequential test requirements/ windfall sites, and general issues described.

Use findings from SFRA to consider vulnerability and risk to people and property.

The Environment Agency must be consulted.

FRAs to be undertaken for all major development sites, including those in Flood Zone 1, (EA is a statutory consultee for any development with an area greater than one hectare).

2 Vulnerability to flooding from other sources as well as Major developments within Flood from river flooding, and the potential to increase flood Zone 1 risk elsewhere through the addition of hard surfaces and the effect of the new development on surface water run-off, should be incorporated in a FRA. See Annex E of PPS25 for minimum requirements and the requirements below for drainage requirements.

All types of development are acceptable and a FRA is not required. Primary concern is the management of Minor developments within Flood Zone surface water (see drainage requirements below). 1 Refer to the standard Environment Agency comments on managing surface water drainage: (www.pipernetworking.com/floodrisk/operational.html). Proposed developments adjacent to Land Drainage Act Consent information applicable. an Ordinary Watercourse Proposed development within 20m of a The Environment Agency must be consulted. Main River Development that requires culverting, operation or the control of the flow of The Environment Agency must be consulted. any river or stream. EA should be consulted as per above recommendations and when the surface water is to drain directly to a main river. Otherwise Water Companies and LPA consultation only will be All drainage and sewer design for new required. developments. Sewers should be designed to ensure that no flooding on site occurs from a 30 year design storm using the worst case critical duration considering 15, 30, 60, 120, 240, 480, 720 and 1440 minute events.

2 Major development is defined in The Town and Country Planning (Flooding) (England) Direction 2007 as: (a) in respect of residential development, a development where the number of dwellings to be provided is 10 or more, or the site area is 0.5 hectares or more; or (b) in respect of non-residential development, a development where the new floorspace to be provided is 1,000 square metres or more, or the site area is 1 hectare or more;

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Development issue General statements/requirements

For events with a return-period between 30 to 100 years, surface flooding of open spaces such as landscaped areas or car parks may be acceptable for short periods, but the layout and landscaping of the site must ensure flooding does not affect property FFL’s or increase off-site flooding.

A climate change allowance of 20% must be applied for industrial/commercial developments and 30% for residential developments.

For greenfield sites, discharge rates must be reduced to 5 l/s per ha for the design (30 year) storm.

For brownfield sites, discharge rates should match greenfield run-off rates (5 l/s per ha). Where it is impractical, it will be the responsibility of the developer to justify why this can not be achieved.

SuDSs should be used on all development sites as a method of achieving the above criteria. Where SuDS are impractical, it will be the responsibility of the developer to justify why.

Regional planning bodies and local LPAs should promote the use of SuDS for the authorities should promote the use of management of run-off. SuDS for the management of run-off.

In addition, the figure below should be used when deciding what should be done when considering flood risk, drainage and the management of watercourses for certain development types. This table can be applied to all development types and should enable the correct consultation response and should be referred to as a first port of call for planning applications. The table below is a March 2007 version, the table is updated over time and the latest version can be found on the following website address. http://www.pipernetworking.com/floodrisk/matrix.html The boxes on the internet version are linked to Environment Agency guidance notes and definitions.

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Figure 8: Flood Risk Assessment Matrix

Development Type Relationship to sources of flooding and Flood Zone s. Development Includes culverting Within Flood Within Flood Within Flood (including or control of flow of Zone 3 Zone 2 Zone 1 boundary walls any river or stream etc.) within 20 metres of the top of a bank of a Main River Hou seholder development Consult EA Consult EA with FRA No consultation - No consultation - No consultation - and alterations showing design see standard see standard No EA Advice (Note 1) details of any culvert comment comment or flow control (Note 6) (Note 6) structure proposed Non -residential extensions Consult EA Consult EA with FRA No consultation - No consultation - No consultation - with a footprint of less than showing design see standard see standard No EA Advice 250m2 details of any culvert comment comment (Note 2) or flow control (Note 6) (Note 6) structure proposed Change of use FROM Water Only consult EA if No consultation - no Consult EA with No consultation - No consultation - Compatible TO 'Less site also falls within EA advice FRA no EA advice No EA Advice Vulnerable' development Flood Zone 3. FRA (Note 3) Required Change of use RESULTING Only consult EA if No consultation - no Consult EA with Consult EA with No consultation - IN 'Highly Vulnerable' or site also falls within EA advice FRA FRA No EA Advice 'More Vulnerable' Flood Zone 3 or 2. development FRA Required (Note 4) Operational development Consult EA Consult EA with FRA Consult EA with Consult EA with No consultation - less than 1 hectare showing design FRA and FRA and see standard (Note 5) details of any culvert Sequential Test Sequential Test comment or flow control Evidence (and Evidence (and (Note 7) structure proposed where required where required confirm confirm Exception Test Exception Test has been has been applied) applied) Operational development of Consult EA Consult EA with FRA Consult EA with Consult EA with Consult EA with 1 hectare or greater showing design FRA and FRA and FRA (Note 5) details of any culvert Sequential Test Sequential Test or flow control Evidence (and Evidence (and structure proposed where required where required confirm confirm Exception Test Exception Test has been has been applied) applied)

Colour Key – Red indicates consultations with the EA is necessary, Grey indicates that no consultation is required. Standard comment - Floor levels within the proposed development will be set no lower than existing levels AND, Flood proofing of the proposed development has been incorporated where appropriate. Or Floor levels within the extension will be set 300mm above the known or modelled 1% (1 in 100 chance each year) river flood level or 0.5% (1 in 200 chance each year) tidal & coastal flood level. NB – for explanation of notes see following pages. This information was correct at the time of writing but is subject to change. For the most up to date information please see http://www.pipernetworking.com/floodrisk/matrix.html

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Notes to Figure 8 Note1 and 2 - Minor development : (i) development of an existing dwelling-house, or development within the curtilage of a dwelling- house, for any purpose incidental to the enjoyment of the dwelling-house as such; (ii) the extension of an existing building used for non-domestic purposes where the footprint created by the development does not exceed 250 square metres; (iii) the alteration of an existing building where the alteration does not increase the size of the building; ". ‘Householder' development includes "sheds, garages, games rooms etc. within the curtilage of the existing dwelling in addition to physical extensions to the existing dwelling itself. This EXCLUDES proposed development that would create a separate dwelling within the curtilage of the existing dwelling e.g. subdivision of houses into flats". Note 3 - 'Water-compatible' development and 'less vulnerable' development (see PPS25 Annex D, Table D.2). Consultation is intended to pick up those proposed developments which may increase flood risk. The Environment Agency will have NO comment to make on any change of use RESULTING IN water- compatible development and should not be consulted. Note 4 - 'Highly vulnerable' and 'more vulnerable' development' (see PPS25 Annex D, Table D.2). Consultation is intended to pick up proposed development which may increase flood risk. This will include changes of use WITHIN these categories. Note 5 - 'Operational development' includes building, mining or engineering works and excludes development involving only a material change of use. The 1 ha threshold is based on the size of the application site as shown on the planning application form or site plan. Note 6 – EA guidance (see below) is designed to cater for domestic extensions as well as the extension of an existing building used for non-domestic purposes where the footprint created by the development does not exceed 250 square metres. In such circumstances: Applicants should complete the table below and include it with the planning application submission. The table, together with the supporting evidence, will form the Flood Risk Assessment (FRA). It will act as an assurance to the Planning Authority that flood risk issues have been addressed as part of the development.

Planning Authorities should check the planning application and ensure that one or other of the mitigation measures proposed in the table have been incorporated into the development.

Applicant to choose one or other of Applicant to provide the LPA Applicant to the flood mitigation measures with the supporting Information tick one of the below. detailed below as part of their boxes below FRA

Either: Floor levels within the Details of any flood resilience and proposed development will be set no resistance techniques to be lower than existing levels AND, Flood included in accordance with proofing of the proposed development ‘Preparing for floods’ (ODPM 2003) has been incorporated where appropriate.

To be demonstrated by a plan that Or: Floor levels within the extension shows finished floor levels relative will be set 300mm above the known to the known or modelled flood or modelled 1% (1 in 100 chance level. each year) river flood level or 0.5% (1 in 200 chance each year) tidal & All levels should be stated in coastal flood level. relation to Ordnance Datum

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Cumulative Impact of Minor Extensions and the Removal of Permitted Development Rights. In circumstances where local knowledge (SFRA/ letters from the parish council etc.) indicate that the cumulative impact of minor extensions may have a significant effect on flood risk (PPS25 paragraph D14), FRA guidance note 2 can be applied. The Environment Agency will comment on minor applications e.g. residential extensions where (a) Permitted development rights have been removed for flood risk reasons, and (b) A local consultation protocol has been agreed between the Environment Agency and the Local Planning Authority Note 7 - For operational developments 3 of less than 1 hectare falling within Flood Zone1, the main flood risk issue to consider will usually be managing surface water run-off (or other forms of flooding). If a known drainage problem exists, the Local Planning Authority should seek assurance from the developer that flood risk has been addressed. Reference should be made to FRA note 1.

If the proposal part of a larger development site? Reserved matters applications in Flood Zone 1 might be part of larger sites, which already have outline permission. In such cases, the LPA should ensure that any conditions that were applied to the larger site to manage surface water drainage are taken into account in the reserved matters application, in order to prevent a ‘piecemeal’ approach to drainage.

Best practice advice-Sustainable Drainage (SuDS) (see Section 9.3) Surface water run-off should be controlled as near to its source as possible through a sustainable drainage approach to surface water management (SuDS). SuDS offer significant advantages over conventional drainage systems by attenuating the rate and quantity of surface water run-off from a site, promoting groundwater recharge, and improving water quality and amenity. Support for the SuDS approach to managing surface water run-off is set out in Planning Policy Statement 1 (PPS): Delivering Sustainable Development and in more detail in Annex F of PPS 25. Part H of the Building Regulations 2000 establishes a hierarchy for surface water disposal, which encourages a SuDS approach. SuDS should be the first option for surface water disposal followed by watercourses and then public sewer systems. It should be demonstrated that that the SuDS options are feasible, can be adopted and properly maintained and would not lead to any other environmental problems e.g. the use soakaways or other infiltration methods on contaminated land carries groundwater pollution risks and may not work in areas with a high water table. An appropriate assessment carried out under BRE Digest 365 should be completed for soakaways. Flow balancing SuDS methods which involve the retention and controlled release of surface water from a site may be considered to maintain the local greenfield run off rate. Flow balancing should seek to achieve water quality and amenity benefits as well as managing flood risk. For further information on SuDS see: - Annex F of PPS 25; - PPS25 Practice Guide; - CIRIA C522 - Sustainable Urban Drainage Systems-design manual for England and Wales; - Interim Code of Practice for Sustainable Drainage Systems; - Section 9.3 of this report. The Interim Code of Practice is available electronically on both the Environment Agency's web site at: www.environment-agency.gov.uk and CIRIA’s web site at: www.ciria.org.uk

Disposal to public sewer Where it is intended to dispose of surface water to a public sewer, either Severn Trent Water or Yorkshire Water should confirm that there is adequate spare capacity in the existing system.

Other flood risk issues to consider for development in Flood Zone 1 - Dry Islands There are some areas within Flood Zone 1 that are surrounded by areas at a higher risk of flooding (‘dry islands’). i.e. areas falling within Flood Zones 3 and 2 In some cases development in these areas can present particular hazards to public safety including risks associated with maintaining safe access and exit for occupants during flood events and access for the emergency services. The local Environment Agency Planning Liaison can advise on such locations within the greater Chesterfield area.

3 Operational developments are those which are not limited purely to material changes of use i.e. they involve works such as building, mining or engineering operations which could have an impact on surface water run-off.

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The Environment Agency will release a new version of Flood Risk Standing Advice in January 2009. This will take account of the vulnerability classifications introduced in table D2 of PPS25, and will have more user-friendly applications designed for Planning Authority use, and for Developer and Applicants use. This will become available directly on their website www.environment-agency.gov.uk 8.7 How to use the SFRA to apply the Sequential Test (a) Local Development Framework This SFRA has looked at existing development sites, sites with planning permission and strategic sites provided by the LPA. Other sites will be brought forward for consideration by the LPA through the SHLAA and as representations for the LPA’s LDF (both by the LPA and by developers and landowners). The SFRA must be used by the LPA to sequentially test these additional sites and use the information provided to strategically assess development in relation to flood risk. This has in part been summarised in Sections 8.4 to 8.5. The process of applying the Sequential Test should be followed as shown in Figure 8 above.

APPLICATION OF THE SEQUENTIAL TEST and EXCEPTION TEST

To sequentially test sites, the following information should be used. 1. GIS themes for the site(s), Flood Zone maps and any functional floodplain extent produced should be prepared by the LPA and brought up on background OS mapping. This will allow the identification of the Flood Zone in which the site is located. 2. Any climate change flood extents that have been produced can be made available by the LPA in GIS. These extents can be included to see if the site could be at risk of flooding in the future from climate change. 3. The functional floodplain (Flood Zone 3b) and climate change flood extents will only be available for certain river reaches which has been assessed during the SFRA. Other areas of functional flood plain may exist where there is no river modelling data. 4. The flood risk problems database and GIS theme should be used to identify potential flood risk from other sources. The SFRA has not established whether there is a low or medium risk of flooding from these other sources (see notes 1 and 2 from Figure 7).

If a developer is making an application then that developer should be notified if it is believed that the site could be at risk from other sources of flooding. The developer should then be asked to further investigate this during a FRA.

5. If the site is located in either Flood Zone 2 or Flood Zone 3 the Sequential Test should be applied to identify and confirm the location of other reasonably available other sites in lower flood risk zones within the LPA area in an effort to steer new development away from these flood risk areas. This applies to all types of development (except essential infrastructure and water compatible) irrespective of whether they are suitable for higher flood risk zones or not. 6. If there are no other reasonably available sites then consideration should be given to applying the Exception Test to allow sites to be brought forward safely. 7. Table D2 in PPS25 should be used to ascertain the vulnerability of a development. This is shown in Table 3, page 33. Table D3 from PPS25 also shown as Figure 5. This assessment can then be used to determine if the proposed development type could be acceptable in a particular Flood Zone (always provided there are not other suitable sites available). 8. Finally the Exception Test will need to be applied if there are other drivers (other than flood risk) requiring the development of certain land uses in Flood Zones 2 or 3.

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(b) Development Control Figure 9 below sets out the information that the Environment Agency will require as evidence from LPAs as a demonstration that the flood risk Sequential Test has been properly applied. For prospective allocations this should be done as part of the LDF process. For windfall sites it will be the responsibility of the developer to submit sufficient justification to the LPA to provide to the EA. Initially on a site specific basis Table 18 and Figure 8 should be used to find out who should be consulted, what guidance needs to be considered, what development is likely to be acceptable, the scope of an FRA and other factors that should be considered. A developer of an individual site should identify if the site has already been assessed in the Addendum. This will provide more details on what is required for an FRA and any other factors to consider. For example other flood risk problems, not identified in the Flood Zone maps, could be identified. The developer should be able to find out from the Addendum whether the Sequential or Exception Test is required for the proposed development type. The basic requirements for an FRA should be identified. The developer can then go to PPS25 for further guidance and consult the LPA and Environment Agency to confirm the requirements. For sites not contained within the Addendum, the developer should establish if the site has been assessed by the LPA through the LDF process. If it has been the subject of assessment, details on what is required for an FRA (as above) will be provided.

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Figure 9: Sequential Test Requirements

Is the proposed development consistent in location, type and scale with an allocated State which plan, Compliance with the site from a development plan YES which allocation and Sequential Test has which has already been the location of the been adequately sequentially tested (i.e. has allocation site in the demonstrated the flood risk Sequential Test development plan FINISH HERE. already been carried out for this site at a strategic level?) YES

YES NO Has the LPA/ Developer to Sequential Test consult the been adequately Development plan demonstrated? Does the application site fall within an area identified to take ‘windfall’ development NO that has been agreed as part of the development plan and in association with a SFRA

NO

Does the development plan or the background documents used to identify potential State which Compliance with the development plan allocation YES allocation(s) and the Sequential Test has sites, contain ‘reasonably location in the NOT been adequately available’ alternative sites that development plan. demonstrated – are situated in a lower flood FINISH HERE . risk zone?

NO LPA/ Developer to consult the Development plan, Background Documents, Environment Does the development plan or Agency Flood Map, SFRA the background documents used to identify potential development plan allocation sites, contain alternative YES ‘reasonably available’ sites that are within the same Flood Zone and subject to a lower probability of flooding from all sources as detailed by the SFRA?

NO

Note: For prospective development allocations this should be done as part of the LDF process. For windfall sites it will be the responsibility of the developer to submit sufficient justification to the LPA to provide to the EA

Flood Risk Policies

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9 Flood Risk Policies

There are a number of existing regional and local policies that relate to the flood risk. These are described in the following sections. In addition, a number of flood risk specific planning policy proposals have been discussed by the project. These are also discussed in the following sections. 9.1 Current Planning Policy Regional Submitted Draft Regional Spatial Strategy for the East Midlands (March 2008) states the following:

Policy 36 – A Regional Approach to Managing Flood Risk Development Plans, future Local Development Frameworks, and strategies of relevant agencies should:

 be informed by the use of appropriate Strategic Flood Risk Assessments in order to evaluate actual flood risk and should include policies which prevent inappropriate development either in, or where there would be an adverse impact on, the coastal and fluvial floodplain areas;  deliver a programme of flood management schemes that also maximise biodiversity and other regeneration benefits; and  require sustainable drainage in all new developments where practicable. Development should not be permitted if, alone or in conjunction with other new development, it would:

 be at unacceptable risk from flooding or create such an unacceptable risk elsewhere;  inhibit the capacity of the floodplain to store water;  impede the flow of floodwater;  have a detrimental impact upon ground water storage capacity;  otherwise unacceptably increase flood risk; and  interfere with coastal processes. However, such development may be acceptable on the basis of conditions or agreements for adequate measures to mitigate the effects on the overall flooding regime, including provision for the maintenance and enhancement (where appropriate) of biodiversity. Any such measures must accord with the flood management regime for that location. Strategic flood risk assessments should be carried out where appropriate to inform the implementation of this policy.

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Local Chesterfield The Replacement Chesterfield Borough Local Plan (June 2006) states the following:

Policy EVR10 – in areas of flood risk shown on the proposal map or otherwise identified by the Environment Agency, applications for developments will be subject to the following restrictions and requirements; In Zone 3 areas identified as protected washlands – development will only be permitted in exceptional circumstances for essential infrastructure which cannot be practicably located elsewhere. In other Zone 3 areas and in Zone 2, planning permission will not be granted if the flood risk assessment indicates that the development would: a) increase the risks of flooding on site and/or elsewhere, whether upstream or downstream; or b) be at risk of flooding itself; or c) impede access to a watercourse for maintenance; or d) not provide adequate flood mitigation and flood warning measures.

Bolsover Bolsover District Local Plan (February 2000) states the following:

Policy GEN 5 – planning permission will only be granted for developments that interact positively with the natural watercourse and land drainage system. The drainage of the system will be protected and permission will not be granted for development which would result in: 1) A reduction in the capacity of the natural floodplain as defined on the proposals map (unless compensatory measures are provided to the satisfaction of the local planning authority); Or 2) Detrimental changes in the characteristics of surface water run-off or groundwater drainage (unless works can be provided on or loss the site to accommodate the effects of the changes); Or 3) new uses at risk in areas liable to flooding; Or 4) loss of access to watercourses for future maintenance and improvement works

NE Derbyshire The North East Derbyshire Local Plan (November 2005) states the following:

Policy NE9 – development proposals will not be permitted in areas at risk of flooding unless: a) the proposals is for an open recreation or open space use; or b) the location is essential for a particular development and there are no alternative locations in a lower risk area; and c) the proposals can be adequately safeguarded against flood risk through appropriate mitigation and/or compensation works; and d) it can be demonstrated that the proposal would have no adverse effects on the management of flood risk either upstream or downstream of the development: i. by a reduction of the capacity or increase in flows in the floodplain; ii. through the discharge of additional surface water; iii. by harming flood defences; and e) adequate provision is made for access to watercourses for maintenance purposes.

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9.2 LDF Draft flood risk policies Flooding issues have long been recognised as a material consideration in the development planning process. In view of the apparent increase in frequency and severity of fluvial flooding in recent years, the Government has asked LPAs to give greater consideration to flood risk in the planning process by discouraging inappropriate development. Government advice is that a precautionary and risk-based approach should be taken in respect of decisions made by LPAs on applications for development consent where flood risk is an issue. Policies should be applied to planning applications based on the Flood Zones defined in PPS25. PPS25 aims to steer development away from areas at risk of flooding. If development does need to take place in a Flood Zone, less vulnerable development types should be considered first and the lower risk Flood Zones should also be considered first. In addition, PPS25 sets guidelines on surface water disposal and developments that interfere with the natural flow of watercourses. The following Draft Flood Risk Policy Recommendations have been prepared for the Chesterfield, Bolsover and North East Derbyshire SFRA.

DRAFT POLICY RECOMMENDATION 1 - The Need for a Flood Risk Assessment The Council may require the submission of an appropriate site specific Flood Risk Assessment from the developer in connection with any application for development consent. The Environment Agency has produced standing advice to assist Local Planning Authorities make decisions on low risk planning applications (i.e www.pipernetworking.com). The standing advice also sets out those higher risk developments on which the EA is a statutory consultee on development and flood risk where the EA needs to be consulted directly by Local Planning Authorities.

If the LPA considers that a proposed development is on land considered to be at risk of flooding or is likely to present a significant flood risk or increased flood risk to other land or property, they may require that the developer submits a site specific Flood Risk Assessment of the development site in connection with the application for planning permission. It should be assumed that a site specific Flood Risk Assessment may be required in most cases, though exceptions will normally be made for minor developments such as alterations to existing buildings. Developers are therefore advised to seek the advice of the LPA before submitting an application as to whether the LPA is likely to require a site specific Flood Risk Assessment. Developers are directed to the “Development and Flood Risk: A Practice Guide Companion to PPS25 ‘Living Draft’. See also guidance on the Sequential Test and the Exception test in Section 8.1 of this SFRA. The site specific Flood Risk Assessment must examine the flood risk issues and implications for the development over its whole lifetime, taking into account (where relevant) the possible impacts of climate change. The Assessment must be appropriate to the location, size, complexity and sensitivity of the development proposal and should address those matters outlined in Annex E of PPS 25. The Assessment should consider the risks of flooding from open watercourses and, where relevant, from surface water sewers and piped drainage systems, groundwater and any artificial sources of flood risk. The site specific Flood Risk Assessment should also address the implications of increased surface water runoff from paved and impermeable areas created by the development for flood risk to land and property downstream of the development. If the Assessment finds that additional surface water runoff is likely to be generated by the development at times of heavy rainfall, the development proposals should incorporate suitable measures to attenuate the additional runoff to levels that existed prior to the development taking place. Consideration of the use of SuDS is recommended. SuDS are dealt with in detail in Draft Policy Recommendation 5. Where a substantial development (e.g. greater than one hectare) is envisaged, the LPA strongly advises developers to consult the Environment Agency before making a formal application for planning consent to discuss:

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 the potential flood risks to their development,  the likely impact of their proposals on flood risk elsewhere,  and what flood risk mitigation measures might be necessary, effective and acceptable. For substantial developments, a site specific Flood Risk Assessment carried out by a competent person will be an essential element in the overall evaluation of the proposed development and its approval by the LPA. Where flood risk alleviation works form a necessary pre-condition of development consent, such works will normally be funded by the developer, probably through a Section 106 Agreement with the LPA. Consent for work next to or in a watercourse will require consent from the EA. Where the proposed alleviation works are likely to require ongoing future maintenance, appropriate agreements shall be entered into prior to their construction to ensure the long term effectiveness of the works .

DRAFT POLICY RECOMMENDATION 2 - Development in areas deemed to be at Low Probability of flooding, (Flood Zone 1) The LPA’s SFRA has classified all land within one or other of the four Flood Zones described in the SFRA. This classification has been undertaken at the strategic level and is intended primarily for guidance purposes in the overall planning process. It should not therefore be regarded as definitive and does not remove the need for site specific FRAs.

A site specific Flood Risk Assessment will be required for all applications for major sites 4. The EA will be a Statutory Consultee for the following situations:

 development within 20m of the bank top of a Main River;  any culverting operation or development which controls the flow of any river or stream;  development other than minor development in Flood Zones 2 & 3;  development in Flood Zone 1 where there are critical drainage problems;  any development exceeding one hectare in extent. The Environment Agency is required to respond to consultations on preplanning enquiries within 21 days, unless otherwise formally agreed in writing. The site specific FRA should consider the potential to increase flood risk elsewhere through the addition of hard surfaces and the effect of the new development on surface water run-off. With these considerations in mind, planning permission will only be granted for development in these areas provided that: A) The development will not itself be at an inappropriate risk of flooding. (It may itself be at risk from other, secondary sources of flooding such as surface water sewers.) B) The development will not create an increased risk of flooding for other persons, land and property. (Even though a development outside the floodplain may not itself be at risk of flooding, it may nevertheless increase the risk to others by increasing the rate and volume of surface water runoff from the development site.) C) All flood risk mitigation measures shall be implemented in accordance with the implementation programme submitted with the approved site specific Flood Risk Assessment before the development is brought into use. Developers should therefore appreciate that a site specific Flood Risk Assessment may still be necessary for developments of Low Probability or Medium to High Probability of flooding.

4 Major development is defined in The Town and Country Planning (Flooding) (England) Direction 2007 as: (a) in respect of residential development, a development where the number of dwellings to be provided is 10 or more, or the site area is 0.5 hectares or more; or (b) in respect of non-residential development, a development where the new floorspace to be provided is 1,000 square metres or more, or the site area is 1 hectare or more;

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DRAFT POLICY RECOMMENDATION 3 - Development in areas deemed to be at Medium to High Probability of flooding (Flood Zones 2 and 3a) Developments within the natural floodplain of a river or stream are inherently at risk of flooding and can also increase flood risks to others, not only by increasing surface water run- off rates but by obstructing or diverting flood flows and reducing flood storage. Planning permission will be granted where the following criteria are met: A) It is considered either appropriate (in developed areas), or essential (in other high risk areas) for development to take place in that location within the criteria set out in Tables D1 and D2 of PPS25 (see section Table 2.2). B) It is protected from flooding to an appropriate standard or is designed to cope with the risk of flooding. C) Ground floor living accommodation is excluded in residential developments where that development is adjacent to a raised flood defence. D) The development does not create an unacceptable obstruction to flow across a floodplain under flood conditions, and does not divert the flow of flood water towards or across adjacent land or property. E) The development does not reduce the volume available for the retention of water on the flood plain in times of flood (i.e. no loss of flood plain storage due to new development, ground raising etc,). F) The development does not jeopardise the integrity of existing flood defences in any way, or obstruct operational access thereto. G) All flood risk mitigation measures shall be implemented in accordance with the implementation programme submitted with the approved Flood Risk Assessment before the development is brought into use. H) For brownfield floodplain redevelopment, natural floodplain should be restored either by reducing the building footprint or by changing the use to a less vulnerable classification.

A development shall not result in a net loss of flood plain storage – i.e. compensation storage can be provided BUT it should be contiguous with the flood plain and connected to the area where flood plain storage is lost. Compensation storage should also be level for level with the flood plain storage lost i.e. if volume is lost from the 1 in 100 year flood plain it cannot be compensated for by additional flood plain storage in the 1 in 25 year flood plain and vice versa. Existing buildings are assumed to take up flood plain storage and need not be compensated for when re-developed. Table 19 summarises which land uses are appropriate in these Flood Zones. This is shown in full in Figure 5. Table 19: Appropriate uses of land in Flood Zones Flood Zone Appropriate uses of land Flood Zone 1 All uses of land are appropriate in this zone Flood Zone 2 The water-compatible, less vulnerable and more vulnerable uses of land and essential infrastructure in Table D.2 from PPS25 are appropriate in this zone. Flood Zone 3a The water-compatible and less vulnerable uses of land in Table D.2 from PPS25 are appropriate in this zone. Flood Zone 3b Only the water-compatible uses and the essential infrastructure listed in Table D.2 from PPS25 that has to be there should be permitted in this zone.

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DRAFT POLICY RECOMMENDATION 4 - Development involving building in areas identified as Functional Floodplain (Flood Zone 3b) A Functional Floodplain is an area of undefended floodplain which is expected to flood on a frequent basis and which, by being allowed to flood, will reduce the risk or severity of flooding elsewhere. The functional floodplain includes water conveyance routes and flood storage areas (sometimes referred to as washlands). Development involving building in areas identified as Functional Floodplain in the SFRA will only be permitted in exceptional circumstances. Specific brownfield sites can be designated as Flood Zone 3a (high risk) and not part of the functional flood plain if agreed between the EA and the LPA (Ref: Section 2.2).

Table 19 outlines which land uses are appropriate in this Flood Zone. This Draft Policy Recommendation is intended to prevent development which might impede the flow of water onto a functional floodplain or reduce the volume available for the temporary storage of flood water in those areas. 9.3 SuDS Sustainable drainage is the practice of controlling surface water runoff as close to its origin as possible before discharge to a watercourse or to a soakaway. It has many benefits relating to a variety of environmental issues such as reducing flood risk, minimising pollution of watercourses and groundwater, minimising soil erosion and damage to natural habitats, maintaining or restoring natural flow regimes in receiving watercourses, maintaining groundwater recharge and achieving environmental enhancements. The many and diverse benefits resulting from the use of SuDS justify the requirement for the widespread use of SuDS in development proposals. Appendix E gives a brief descrition of the use of SuDS and sustainable development.

DRAFT POLICY RECOMMENDATION 5 - Sustainable Drainage Systems (SuDS) The LPA should require developers to demonstrate that their surface water drainage proposals, particularly for large sites, are appropriate and adequate for the development and will not increase the flood risk to land and property either upstream or downstream of the development site. The Council considers that Sustainable Drainage Systems (SuDS) are a desirable means of achieving this and encourages their use by developers. Planning permission for site without SuDS will not usually be granted unless the Developer can provide sufficient justification as to why SuDS are inappropriate, unfeasible or unnecessary at the proposed development site.

New development, especially of greenfield sites, alters the existing drainage characteristics of an area with roofs, roads and other impermeable surfaces from which rainfall is more rapidly translated into runoff. The management and control of this increased surface runoff has a major role in sustainable development. 9.4 Culverting of Open Watercourses

DRAFT POLICY RECOMMENDATION 6 - Culverting of Open Watercourses The Environment Agency and Council are in general opposed to the culverting of open watercourses because of the adverse ecological effect, potentially increased flood risk and other consequences that are likely to arise. Where practical in connection with the development proposals, LPAs should seek to have existing culverted watercourses restored to open channels, using planning conditions or S106 legal agreements.

The LPA will therefore only approve plans to culvert an open watercourse if there is no reasonably practical alternative to culverting, or if the detrimental effects of culverting would be so minor that they would not justify a more costly alternative. In all cases where it is

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appropriate to do so adequate mitigation must be provided for damage caused to natural habitats and to animal, plant and other species by the culverting. If culverting is approved, the size and material of the pipes used must be adequate to convey flood flows in the watercourse and able to support any vehicular or other load likely to be imposed upon the culvert. The developer may be required to demonstrate to the LPA with appropriate hydraulic calculations that the culvert will adequately convey the flood flow in the watercourse without exacerbating flooding upstream or along the line of the culvert. The LPA will not normally approve the installation of a culvert of smaller size than one further upstream on the same watercourse. Culverts, especially in urban areas, are liable to become obstructed or blocked by debris carried by flood waters or by illegally deposited rubbish. The LPA may therefore require a screen of a suitable design to be erected at the entrance to the culvert. The design of the screen must permit safe and convenient access for the removal of debris and rubbish. Where the culvert is longer than twenty metres, the LPA may require the installation of one or more intermediate access manholes on the line of the culvert for maintenance purposes. 9.5 Climate Change It is generally accepted that climate change is happening and is likely to cause an increase in flood risk in the future. As such, draft policy 7 has been included to allow councils to manage climate change at development level.

DRAFT POLICY RECOMMENDATION 7 - Climate Change All new developments must take account of climate change both for river flows and surface water run-off. River flows should be assumed to increase by 10% or 20% and peak rainfall intensity by 10%, 20% or 30% depending on the lifetime of the development. Current guidance defines development lifetimes of 30 years for retail, 60 years for commercial/industry and 100 years for residential. Climate change allowances should be in accordance with Planning Policy Statement 25.

9.6 Afforestation Afforestation outside floodplains is beneficial and can reduce runoff and flood risk if undertaken in a sustainable manner. Afforestation within floodplains is more complex, can cause both positive and negative effects and would need to be reviewed as part of a catchment wide hydraulic modeling exercise.

DRAFT POLICY RECOMMENDATION 8 - Afforestation Opportunities for afforestation (outside of the floodplain) should be considered and implemented wherever practical. Deforestation and other significant tree loss should be avoided, especially clear cutting.

9.7 Increased Impermeability It is widely understood that a major factor for increased flood risk in urban areas is due to small (but many) increases in impermeable area (e.g. paving driveways and gardens). It is likely that planning permission will be required in the future for similar such development. Draft policy 8 aims to tackle this issue prior to any legislation being in place.

DRAFT POLICY RECOMMENDATION 9 - Increased Impermeability Increases in impermeable area requiring planning permission will not normally be permitted unless it can be demonstrated that the run-off from these areas will not be increased. This could be achieved by the following:

 Sustainable drainage techniques such as permeable pavements and infiltration;  Underground storage and flow control.

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9.8 Runoff Rates For events with a return-period between 30 to 100 years, surface flooding of open spaces such as landscaped areas or car parks may be acceptable for short periods, but the layout and landscaping of the site must ensure flooding does not affect property FFL’s or increase off-site flooding. A climate change allowance of 20% must be applied for industrial/commercial developments and 30% for residential developments. For greenfield sites, discharge rates must be reduced to 5 l/s per ha for the design (30 year) storm. For brownfield sites, discharge rates should match greenfield run-off rates (5 l/s per ha). Where it is impractical, it will be the responsibility of the developer to justify why this can not be achieved. SuDSs should be used on all development sites as a method of achieving the above criteria. Where SuDS are impractical, it will be the responsibility of the developer to justify why.

DRAFT POLICY RECOMMENDATION 10 - Runoff Rates PPS 25 requires flood risk to be reduced wherever possible by limiting peak surface water discharge but national guidance on the expected scale of reduction is not consistent. Recommendations vary from no detriment to a preference that brown field solutions provide similar run-off characteristics to green field development. Consequently the Local Authority will seek the maximum possible reduction as follows:- For sites currently draining direct to sewer or watercourse and proposals to use the same outlet(s), a minimum of 30% reduction in peak discharge. Indirect drainage via the highway is not included in the calculation of existing flow. For sites not currently drained or to be drained to alternative outlets, peak discharge to be restricted to 5 litres per second per hectare with a 5 litres per second minimum/per site (i.e. sites < 1hectare would have a discharge of 5l/s).

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Conclusions and Recommendations

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10 Conclusions and Recommendations

10.1 Conclusions A SFRA has been produced for the combined area of Chesterfield, Bolsover and North East Derbyshire. The study has identified the existing areas of flood risk across the LPA area from all sources. Where there are proposed development sites in areas at risk of flooding, the assessment has identified which potential development sites are most at risk and from what source of flooding. The culmination is a flood risk matrix and guidance notes that should enable the LPA to ensure that development types are sensitively located with consideration to flood risk. All available data (September 2007) has been collected from the LPAs. In some areas there is a need for more detailed information which would improve knowledge of flood risk within the LPA areas. This includes modelled river reaches. There is also existing data which has not been made available for this study e.g. some sewer flooding information and drainage network GIS data. Chesterfield, Bolsover and North East Derbyshire are at risk of flooding from a number of sources and mechanisms including watercourse overtopping, flooding from rivers due to defence failure, surface water sewer and foul sewer flooding, runoff and land drainage and the failure of artificial sources i.e. canals and reservoirs. Using the available data, flood maps have been produced for different return periods and climate change extents. The potential impact of climate change has been considered across the LPA area. Levels of risk within the flood extents have been estimated where there is the necessary available data. There are records of flooding Chesterfield, Bolsover and North East Derbyshire at a number of locations predominately from the River Rother in Chesterfield and North East Derbyshire and from the River Doe Lea in Bolsover. Section 5 in the report outlines areas of main concern as being at significant and/or frequent risk of flooding. There are also likely to be isolated problems due to sewer and culvert failure/blockage and minor watercourse flooding. Using the available data, flood maps have been produced for different return periods and climate change extents (where models are available). Where there are river structures along the urban watercourses flood risk may increase due to higher flows occurring more often. There are existing best practice policies in place and draft policy recommendations for flood risk and development have been drafted as part of the SFRA process, including policies for SuDS. Provided these policies are implemented and adhered to, changes in land use are not expected to have a great impact on flood risk but the abandonment of assets could increase flood risk sporadically across the three councils’ area. In some cases proposed developments will be located in areas behind existing flood defences. This could result in an intensification of property at risk, potentially putting a greater burden on the emergency services during a flooding incident. Furthermore, in some cases defences, river channels and culverts may be shown to be in (or approaching) a state of dilapidation that would require additional expenditure to return them to the required level of service. In some instances therefore it may be beneficial to require a contribution to either upgrade or more intensively maintain existing infrastructure to ensure that a development remains safe. Flood risk and the condition/standards of protection provided by defences are not static – climate change, increased urbanisation and changes to urban and agricultural land use can have an impact on flow and water levels; defences can deteriorate with time. Furthermore, new information on flood risk will become available, both from the Environment Agency and other bodies such as the water companies (reservoir failure and failure of sewerage/water distribution systems), British Waterways, etc. Therefore the SFRA will over time become out of date and will need to be updated to reflect condition and policy.

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10.2 Recommendations During the course of the work a number of specific recommendations for additional work have been identified. These are described below:

 Flood Risk Assessments should assess risk from all sources including canals. Rather than many different developers completing a separate assessment, in some cases, it is recommended that one study is completed to cover several adjacent/complementary allocations. This should cover both the issues of overtopping and breach.

 Afforestation outside floodplains is beneficial and can reduce runoff and flood risk if undertaken in a sustainable manner. Afforestation measures minimise soil loss and reduce sediment load in streams and rivers, thus moderating flash floods and controlling the meandering tendency of rivers, thereby minimising the erosion of banks and embankments. Deforestation and other significant tree loss and especially clear cutting should be avoided. Further studies required to recommend where specific sites would be suitable for afforestation.

 The guidance and matrix in the report should be used for all developments in order to identify appropriate and correct consultation processes and requirements for preparing a site specific FRA, as supplemented by central government and/or the Environment Agency from time to time.

 The LPA should use the SFRA in assessing potential sites to be allocated through the LDF.

 Developer contributions towards flood protection, strategic Sustainable Drainage Systems (SuDS) facilities, land drainage, and flood mitigation etc. may be required for some developments. This will be dealt with on a case by case basis.

 Surface water runoff arising from a developed site should, as far as is practicable, be managed in a sustainable manner to mimic the surface water flows arising from the site prior to the proposed development, while reducing the flood risk to the site itself and elsewhere, taking climate change into account. This should be demonstrated as part of the flood risk assessment and considered at all stages of the planning process.

 The SFRA should be reviewed on a bi-annual basis to ensure that the latest flood risk data is available in making informed development allocation decisions

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Glossary

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Glossary

Aquifer A geological stratum (or rock layer) that bears water.

Attenuation Reduction of peak flow and increased duration of a flow event.

Breach Analysis Computational analysis of a breach in the defences that assesses flood depths and velocity to inform an assessment of flood risk to people.

Brownfield A new development on land that has been developed previously, and may Development have become derelict or disused.

Catchment A surface wa ter catchment is the total area that drains into a river. A groundwater catchment is the total area that contributes to the groundwater component of the river flow.

Catchment Flood A strategic planning tool through which the Environment Agency will seek to Management work with other key decision-makers within a river catchment to identify and Plans agree policies for sustainable flood risk management. (CFMP)

DG5 Register Register held by water companies on the location of properties at risk of / have suffered from reportable sewage flooding problems

Environment Non-departmental public body responsible for the delivery of government Agency policy relating to the environment and flood risk management in England and Wales.

Flood Alleviation A scheme designed to reduce the risk of flooding in a specific location. Scheme (FAS)

Flood and Coastal The Environment Agency, LPAs and Internal Drainage Boards with Defence Operating legislative powers to undertake flood and coastal defence works. Authorities

Flood avoidance Constructing a building and its surrounds in such a way to avoid it being (at site level) flooded (e.g. by raising it above flood level, re-siting outside flood risk area etc.)

Flood defence Flood defence infrastructure, such as flood walls and embankments, intended to protect an area against flooding to a specified standard of protection.

Floodlocking Where a receiving stream or river is in flood, especially where that watercourse is contained within raised floodwalls or banks, the flow in the local drainage system can no longer drain to the river and is impounded behind the defence line for the duration of the flood.

Flood Risk The level of flood risk is the product of the frequency or likelihood of the flood events and their consequences (such as loss, damage, harm, distress and disruption).

Flood Risk The activity of modifying the frequency or consequences of flooding to an Management appropriate level (commensurate with land use), and monitoring to ensure that flood risks remain at the proposed level. This should take account of other water level management requirements, and opportunities and

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constraints. It is not just the application of physical flood defence measures. Flood risk A long-term approach setting out the objectives and options for managing management flood risk taking into account a broad range of technical, social, strategy environmental and economic issues.

Flood Envelope Extent of an area that can be flooded.

Floodplain Area of land that borders a watercourse, an estuary or the sea, over which water flows in time of flood, or would flow but for the presence of flood defences where they exist.

Flood risk A study to assess the risk to an area or site from flooding, now and in the assessment future, and to assess the impact that any changes or development on the (covers all scales site or area will have on flood risk to the site and elsewhere. It may also of identify, particularly at more local levels, how to manage those changes to assessment) ensure that flood risk is not increased. PPS25 differentiates between regional, sub-regional/strategic and FRAs.

Flood risk Any measure which reduces flood risk such as flood defences. management Measure

Flood risk profile The level of flood risk used for the SFRA. This is based on flow velocities, depths and distance for flood defences, if present.

Flood Warning Within Flood Warning Areas, warnings of impending flooding are issued by Areas the Environment Agency to business and the public to enable people to take preventative action to protect themselves and their property. Formal procedures are followed to guide when and how warnings are issued.

Flood Zone A geographic area within which the flood risk is in a particular range as defined within PPS25.

Flood Map A map produced by the Environment Agency providing an indication of the likelihood of flooding within all areas of England and Wales, assuming there are no flood defences.

Fluvial Pertaining to a watercourse (river or stream).

Freeboard The difference between the flood defence level and the design flood level.

Functional PPS25 defines a Functional Floodplain as land where water has to flow or floodplain be stored in times of flood. Specifically, this land:  would flood with an annual probability of 1 in 20 (5 per cent) or greater in any year, or at another probability to be agreed between the LPA and the Environment Agency (EA), or:  is designed to flood in an extreme (0.1 per cent) flood, or at another probability to be agreed between the LPA and the EA.

Geographical A GIS is a computer-based system for capturing, storing, checking, Information integrating, manipulating, analysing and displaying data that are spatially System (GIS) referenced.

Greenfield land Land that has not been previously developed.

Hydraulic Model A computational model that simulates how water flows through the physical characteristics of a river channel and floodplain. The model can be used to determine peak water levels, peak flows, discharge volumes and flood event durations along a river system for a specific modelled event.

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Land Use Various designations of activities, developments, cropping types, etc for which land is used.

Land Various forms of activities relating to agricultural, forestry, etc practice. Management

LiDAR Light Detection and Ranging (LiDAR) is an airborne surveying / mapping technique, which uses a laser to measure the distance between the aircraft and the ground. The results of LiDAR surveys are used to develop digital elevation models.

Local Authority A statutory land development plan produced by a District Council. This plan Development sets out policy for development in the district and allocations of land for Plans housing, employment, and transport and leisure.

These statutory land development plans generally cover a 10-15-year period from the date of their adoption. These were produced under the old planning system and are now being replaced by the Local Development Frameworks.

Local A folder of documents which includes all the LPA’s Local Development development Documents (LDDs). The local development framework will also comprise the framework Statement of Community Involvement, the local development scheme and the annual monitoring report.

Local All development plan documents which will form part of the statutory Development development plan, as well as supplementary planning documents which do not Documents form part of the statutory development plan. (LDDs)

Local Plan See Local Authority Development Plans

Local A group required under the Civil Contingencies Act, 2004 who are responsible Resilience for the co-ordination of emergency planning within local areas. Forum

Main River A watercourse designated on a statutory map of Main Rivers, maintained by Defra, on which the Environment Agency has permissive powers to construct and maintain flood defences.

Major A major development is a) where the number of dwellings to be provided is ten development or more, or the site area is 0.5 ha or more or b) non-residential development, where the floorspace to be provided is 1,000m2 or more, or the site area is 1 ha or more. (Ref PPS25 page 9)

Minor  Minor non–residential extensions: Industrial/Commercial/Leisure etc. development extensions with a footprint less than 250 m2.  Alterations: development that does not increase the size of buildings eg alterations to external appearance.  ‘Householder’ development: eg sheds, garages, games rooms etc. within the curtilage of the existing dwelling in addition to physical extensions to the existing dwelling itself. This definition EXCLUDES any proposed development that would create a separate dwelling within the curtilage of the existing dwelling eg subdivision of houses into flats.

NFCDD National Flood and Coastal Defence Database

Ordinary All rivers, streams, ditches, drains, cuts, dykes, sluices, sewers (other than watercourse public sewer) and passages through which water flows which do not form part of a Main River. LPAs and where relevant, Internal Drainage Boards have similar permissive powers on ordinary watercourses, as the Environment

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Agency has on Main Rivers.

Outfall An outfall is the discharge point of a waste stream into a body of water; alternatively it may be the outlet of a river , drain or a sewer where it discharges into the sea , a lake or the like.

Planning A statement of policy issued by central Government to replace Planning Policy Policy Guidance notes. Advice on practical implementation is not included in Planning Statement Policy Statements.

Planning PPS25 sets out government policy on development and flood risk. This Policy replaces PPG Note 25 (published July 2001). Its aims are to ensure that flood Statement 25: risk is taken into account at all stages in the planning process to avoid Development inappropriate development in areas at risk of flooding, and to direct and Flood Risk development away from areas of highest risk. Where new development is, (PPS25) exceptionally, necessary in such areas, policy aims to make it safe, without increasing flood risk elsewhere, and, where possible, reducing flood risk overall. For further information please refer to the communities and local government website: http://www.communities.gov.uk/index.asp?id=1504640

Previously- Land which is or was occupied by a permanent structure, including the curtilage developed of the developed land and any associated fixed surface infrastructure (PPS3 land Annex B) (often referred to as brownfield land)

Regional A broad development strategy for a region for a 15 to 20 year period prepared spatial strategy by the Regional Planning Body. (RSS)

Resilience Constructing the building in such a way that although flood water may enter the (Flood building, its impact is minimised (i.e. no permanent damage is caused, Resilience) structural integrity is maintained and dry and cleaning are facilitated.

Reservoir A reservoir that holds at least 25,000 cubic metres of water above natural (large raised) ground level, as defined by the Reservoirs Act, 1975.

Return period The long-term average period between events of a given magnitude which have the same annual exceedence probability of occurring.

Residual risk The risk which remains after all risk avoidance, reduction and mitigation measures have been implemented.

Resistance Constructing a building in such a way to prevent floodwater entering the (Flood building and damaging its fabric Resistance)

River basin A management plan for all river basins required by the Water Framework management Directive. These documents will establish a strategic plan for the long term plan management of the River Basin District, set out objectives for waterbodies and in broad terms what measures are planned to meet these objectives, and act as the main reporting mechanism to the European Commission

Run-off The flow of water from an area caused by rainfall.

Section 106 Section 106 of the Town and Country Planning Act 1990 (as amended) allows Agreement LPAs to negotiate arrangements whereby the developer makes some undertaking if he/she obtains planning permission. These are known interchangeably as planning agreements, planning obligations or planning gain.

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Standard of The design event or standard to which a building, asset or area is protected protection against flooding, generally expressed as an annual exceedence probability.

Strategic European Community Directive (2001/42/EC) on the assessment of the effects Environmental of certain plans and programmes on the environment. Assessment (SEA) Directive

Surface Water Water that drains across the surface of the land and into sewerage systems designed to accept surface water flows.

Sustainable A sequence of management practices and control structures, often referred to Drainage as SUDS, designed to drain water in a more sustainable manner than some Systems conventional techniques. Typically these are used to attenuate run-off from (SUDS) development sites.

Sustainability An integral part of the plan-making process which seeks to appraise the Appraisal economic, social and environmental effects of a plan in order to inform decision-making that aligns with sustainable development principles.

Washland An area of the floodplain that is allowed to flood or is deliberately flooded by a river or stream for flood management purposes.

Water A European Community Directive (2000/60/EC) of the European Parliament Framework and Council designed to integrate the way we manage water bodies across Directive Europe. It requires all inland and coastal waters to reach “good status” by 2015 through a catchment based system of River Basin Management Plans (RBMP) incorporating a programme of measures to improve the status of all natural water bodies.

Windfall sites Sites which become available for development unexpectedly and are therefore not included as allocated land in a planning authority’s development plan or LDF.