County Durham Outline Water Cycle Study

Home , Bournmoor, Burnhope, Northumbrian Water, Sacriston, Satley, Trimdon

Water Durham County Council March 2012

Final Report

Water Durham County Council March 2012

Prepared by: Christian Lomax Checked by: Alex Perryman Associate Director Consultant

Approved by: Roy Lobley Associate Director

County Durham Outline Water Cycle Study

Rev No Comments Checked by Approved Date by 0 Draft for comment CL VH Feb 2011 1 Update based on new data AP RL Feb 2012 2 Final Report incorporating feedback AP RL March 2012

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Job No: 60155102.M012 Reference: Outline WCS Date Created: March 2012

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Table of Contents

Abbreviations ...... 1

Glossary ...... 3

1 Introduction...... 7 1.1 Background ...... 7 1.2 The Water Cycle ...... 7 1.3 What is a Water Cycle Study? ...... 7 1.4 Partnership ...... 8 1.5 Links with Other Studies ...... 9

2 Future Housing Development ...... 12 2.1 Introduction ...... 12 2.2 Planning Policy Context within County Durham ...... 12 2.3 Housing Development in County Durham: 2011/12 – 2030/31 ...... 12

3 Water Resources and Water Supply ...... 17 3.1 Introduction ...... 17 3.2 Water Resources & the Environment Agency ...... 17 3.3 Water Resources & Northumbrian Water ...... 19 3.4 Water Supply & Northumbrian Water ...... 20 3.5 Conclusions ...... 20

4 Sewerage and Sewage Treatment ...... 22 4.1 Introduction ...... 22 4.2 Sewerage ...... 22 4.3 Sewage Treatment ...... 24 4.4 Conclusions ...... 31

5 Water Quality and Other Environmental Considerations ...... 33 5.1 Introduction ...... 33 5.2 The Strategic Water Environment in County Durham ...... 33 5.3 Water Framework Directive Classification ...... 34 5.4 Geology ...... 40 5.5 Nature Conservation Areas and Protected Areas...... 43 5.6 Conclusions ...... 46

6 Flood Risk ...... 48 6.1 Introduction ...... 48 6.2 Catchment Flood Management Plans ...... 48 6.3 Strategic Flood Risk Assessment ...... 50 6.4 Preliminary Flood Risk Assessment ...... 51 6.5 Surface Water Management Plan ...... 52 6.6 Northumbrian Water Flood Data ...... 55 6.7 Conclusions ...... 56

7 Conclusions ...... 58 7.1 Introduction ...... 58 7.2 Water Resources & Supply ...... 58 7.3 Sewerage and Sewage Treatment ...... 58 7.4 Water Quality and Environmental Considerations ...... 58 7.5 Flood Risk Management ...... 59 7.6 Summary ...... 59

8 Guidance for Developers - SuDS ...... 61 8.1 Introduction ...... 61 8.2 What are SuDS? ...... 61

8.3 Selection of Appropriate SuDS ...... 62 8.4 Different Types of SuDS ...... 63 8.5 Summary ...... 66

LIST OF APPENDICES

Appendix A: Water Quality Legislation Review ...... 69 Appendix B: Relevant Programme of Measures from the Northumberland RBMP ...... 71 Appendix C: SHLAA Sites Potentially at Risk of Surface Water ...... 76 Appendix D: SUDS Potential from SFRA Level 1 (Golder Associates, 2010) ...... 86

LIST OF TABLES

Table 1.1: Roles & Responsibilities ...... 9 Table 2.1: County Durham Strategic Sites ...... 13 Table 2.2: Phasing of County Durham’s SHLAA Sites ...... 14 Table 2.3: Settlements Forecast to Grow by more than 250 Houses ...... 15 Table 3.1: CAMS resource availability status categories ...... 17 Table 3.2: River Wear CAMS - Water Resource Availability ...... 18 Table 3.3: River Skerne - Water Resource Availability ...... 18 Table 3.4: River Derwent - Water Resource Availability ...... 19 Table 4.1: Sewage Treatment Headroom Status ...... 24 Table 4.2: Strategic Sites & STWs ...... 29 Table 5.1: Status objectives for water bodies in the Northumbria River Basin District* (RBD) ...... 35 Table 5.2: GQA Results for 2008 ...... 36 Table 6.1: Flood Zones (Adapted from PPS25, Table D.1) ...... 50 Table 6.2: Development sites that provide opportunities to manage the risk of surface water flooding ...... 54 Table 8.1: Benefits of SuDS ...... 62 Table 8.2: Common SuDS...... 64 Table 8.3: Capability of different SUDS techniques (Extract from CIRIA C697, Table 1.7)...... 67

LIST OF FIGURES

Figure 2.1: Potential Housing Sites ...... 14 Figure 4.1: Incidents of Sewer Flooding ...... 23 Figure 4.1: Timeline of STW Headroom being Reached ...... 27 Figure 4.2: STWs Headroom ...... 28 Figure 5.1: Main Rivers ...... 34 Figure 5.2: GQA Biology ...... 36 Figure 5.3: GQA Chemistry ...... 37 Figure 5.5: WFD Status of Water Bodies in County Durham ...... 39 Figure 5.6: Source Protection Zones ...... 41 Figure 5.7: Magnesian Limestone Aquifer ...... 42 Figure 5.8: Environmental Designations ...... 44 Figure 5.9: Nitrate Vulnerable Zone ...... 45 Figure 6.1: CFMP Policies ...... 49 Figure 6.2: Flood Zones ...... 51 Figure 6.3: Key Surface Water Risk Areas ...... 53 Figure 6.4: Concentrations of Sewer Flooding ...... 55

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Abbreviations

AMP Asset Management Period

AWB Artificial Water Body

CAMS Catchment Abstraction Management Strategy

CFMP Catchment Flood Management Plan

DrWPA Drinking Water Protected Areas

FRA Flood Risk Assessment

GI Green Infrastructure

GIS Geographical Information Systems

GQA General Quality Assessment

GWMU Groundwater Management Unit

HMWB Heavily Modified Water Body

IDP Infrastructure Delivery Plan

LLFA Lead Local Flood Authority

NVZ Nitrate Vulnerable Zone

PFRA Preliminary Flood Risk Assessment

RBD River Basin District

RBMP River Basin Management Pan

SAC Special Area of Conservation

SFRA Strategic Flood Risk Assessment

SHLAA Strategic Housing Land Availability Assessment

SPA Special Protection Area

SPZ Source Protection Zone

SSSI Site of Special Scientific Interest

STW Sewage Treatment Works

SWMP Surface Water Management Plan AECOM County Durham Outline Water Cycle Study 2 Capabilities on project: Water Environment

SWRA Surface Water Risk Area

SuDS Sustainable Drainage Systems

WCS Water Cycle Study

WFD Water Framework Directive

WPZ Water Protection Zone

WRMP Water Resource Management Plan

WRMU Water Resource Management Unit

WRZ Water Resource Zone

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Glossary

Asset Management Period (AMP) – investment in the water industry is broken down into AMPs which comprise five year periods. The current AMP is AMP5 running from 2010 to 2015. Capacity – in the context of the WCS capacity refers to the ability of pipes and STWs to receive water or wastewater. Catchment Abstraction Management Strategy (CAMS) – a strategy to assess how much water can be abstracted to meet its many economic uses – agriculture, industry, and drinking water supply – while leaving sufficient water in the environment to meet ecological needs. Catchment Flood Management Plan (CFMP) – a strategic plan in which the Environment Agency seek to understand the factors that contribute to flood risk in a catchment (e.g. land use), and to identify and agree policies for sustainable flood risk management across a river catchment for the next 50-100 years. Department for Environment, Food and Rural Affairs (Defra) – Department that brings together the interests of farmers and the countryside; the environment and the rural economy; the food we eat, the air we breathe and the water we drink. Environment Agency – The Environment Agency was established under the Environment Act 1995, and is a Non-Departmental Public Body of Defra. The Environment Agency is the leading public body for protecting and improving the environment in England and Wales today and for future generations. The organisation is responsible for wide ranging matters, including the management of all forms of flood risk, water resources, water quality, waste regulation, pollution control, inland fisheries, recreation, conservation and navigation of inland waterways. It will also have a new strategic overview for all forms of inland flooding. Flood Risk Assessment (FRA) – a FRA is required under PPS25 at the planning application stage for new developments. An FRA will demonstrate how flood risk from all sources to the development itself and flood risk to others will be managed now and in the future (including climate change). Floods and Water Management Act (2010) – Act of Parliament to clarify the legislative framework for managing surface water flood risk in England. General Quality Assessment (GQA) Programme – the Environment Agency's method for classifying the water quality of rivers and canals is known as the General Quality Assessment scheme (GQA). It is designed to provide an accurate and consistent assessment of the state of water quality and changes in this state over time. Green Infrastructure – is the network of multifunctional green and undeveloped land, urban and rural, which supports the activity, health and well being of local people and wildlife. Interim Code of Practice for SuDS – A guidance document produced by CIRIA, which aims to facilitate the implementation of sustainable drainage in developments in England and Wales by providing model maintenance agreements and advice on their use. It provides a set of agreements between those public organisations with statutory or regulatory responsibilities relating to SuDS. Local Authority or Local Planning Authority (LA or LPA) – the Local Authority or Council that is empowered by law to exercise planning functions. Often the Local Borough or District Council, National Parks and the Broads Authority are also considered to be local planning authorities. County Councils are the authority for waste and minerals matters. Main River – Generally main rivers are larger streams or rivers, but can be smaller watercourses. Main Rivers are determined by Defra in England, and the Environment Agency has legal responsibility for them. Ordinary watercourse - An ordinary watercourse is any other river, stream, ditch, cut, sluice, dyke or non-public sewer which is not a Main River. The Local Authority or Internal Drainage Board have powers for such watercourses. Planning Policy Statements (PPS) and Planning Policy Guidance (PPG) – these documents set out the Government’s national policies on different aspect of planning. The policies in these statements apply throughout England and focus on procedural policy and the process of preparing local development documents.

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Potable Water – water of sufficiently high quality that it can be consumed or used without risk of immediate or long term harm. In most developed countries, the water supplied to households, commerce and industry is all of potable water standard, even though only a very small proportion is actually consumed or used in food preparation. Also known as drinking water. River Basin Management Plans (RBMP) - A management plan for all river basins required by the Water Framework Directive. These documents will establish a strategic plan for the long-term 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. Sewage Treatment Works (STW) – Water services infrastructure that receives waste water effluent from the sewer network. A STW uses a combination of physical, biological and chemical processes to remove pollutants from the sewage before discharging the treated effluent to the water environment. Sewer – a pipe used to convey surface water, sewerage or both. Sewerage – the infrastructure that conveys sewage or wastewater. It encompasses receiving drains, manholes, pumping stations, storm overflows, screening chambers, etc. Sewerage ends at the entry to a sewage treatment plant or at the point of discharge into the environment. Site of Special Scientific Interest (SSSI) – a site identified under the Wildlife and Countryside Act 1981 (as amended by the Countryside and Rights of Way Act 2000) as an area of special interest by reason of any of its flora, fauna, geological or physiographical features (basically, plants, animals, and natural features relating to the Earth's structure). Special Areas of Conservation (SAC) – a site designated under the European Community Habitats Directive, to protect internationally important natural habitats and species. Special Protection Area (SPA) – sites classified under the European Community Directive on Wild Birds to protect internationally important bird species. Strategic Flood Risk Assessment (SFRA) – an assessment of flood risk from all sources which is used to inform the planning process of flood risk and provides information on future risk over a wide spatial area. It is also used as a planning tool to examine the sustainability of the proposed development allocations. SFRAs form the basis of flood risk management in England and are a requirement of PPS25. Supplementary Planning Documents (SPD) - supplementary planning documents can give further context and detail to local development plan policies. It is not part of the statutory development plan. Therefore, it does not have the same weight when local planning authorities are considering planning applications. Surface Water Flooding - surface water flooding describes flooding from sewers, drains, groundwater, and runoff from land, small water courses and ditches that occurs as a result of heavy rainfall. Surface Water Management Plan (SWMP) - is a plan which outlines the preferred surface water management strategy in a given location. Sustainable Drainage Systems (SUDS) – Sustainable drainage systems (previously referred to as sustainable urban drainage systems): a sequence of source control, management practices and control structures designed to drain surface water in a more sustainable fashion than some conventional techniques (may also be referred to as SUDS or SDS). Water Cycle Study (WCS) – The purpose of a water cycle strategy is to strategically plan the most sustainable water infrastructure in a timely manner, across all of the water cycle from water supply and water resources, flood risk and surface water drainage, and wastewater and biodiversity. Water Framework Directive (WFD) – A European Community Directive (2000/60/EC) of the European Parliament and Council designed to integrate the way water bodies are managed across Europe. It requires all inland and coastal waters to reach “good status” by 2015 through a catchment-based system of River Basin Management Plans, incorporating a programme of measures to improve the status of all natural water bodies.

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Water Resource Management Plan - Every five years water companies in England and Wales are required to produce a Water Resources Management Plan that outlines how they aim to meet predicted demand for water over the next 25 years. Water Resources - Water which is available for human use. Water Resource Zone – a geographical area defined by the water supply/demand balance in the region such that all customers within it receive the same level of service in terms of reliability of water supply. Water Supply – The provision of water to homes and industry using a pipe network.

Introduction

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1 Introduction

1.1 Background The County Durham Plan sets out the planning framework and policies for the County, and makes a commitment to significant housing growth during the period to 2030. A critical component of the infrastructure required to support new housing development is associated with water; the provision of clean water, the safe disposal of wastewater, and protection from flooding. When large numbers of houses are built, as is the proposed situation for County Durham, there is a risk that the existing infrastructure will be overwhelmed, and both the environment and people's quality of life will suffer. In light of this AECOM has been appointed by Durham County Council to undertake a Water Cycle Study (WCS) covering all of County Durham which will form part of the evidence base for the County Durham Plan by providing a review of the capacity of the water cycle to accomodate significant housing growth. 1.2 The Water Cycle The water cycle, describes the continuous movement of water on, above, and below the surface of the Earth. Water evaporates, forms clouds and falls over the land surface as precipitation in the form of rain, snow, or sleet. The precipitation subsequently flows over the ground surface into rivers which flow into lakes and the sea. Precipitation which does not reach rivers may evaporate or infiltrate the ground entering groundwater storage. This natural cycle of water has been interrupted to facilitate development. Water is intercepted and stored in reservoirs or abstracted directly from rivers and groundwater aquifers, and treated to potable quality before it is supplied through an extensive pipe system to homes and industry. Some of this water is used to transport waste through a network of sewers to Sewage Treatment Works which discharge effluent into rivers or the sea. Excessive precipitation over rural or urban areas presents a risk of flooding. This is a natural phenomenon however can cause problems if inappropriate development has taken place without due regard for the risk. Precipitation falling on urban areas can pose a risk of surface water flooding therefore historically it has been collected by an extensive drainage system of sewers for disposal.

1.3 What is a Water Cycle Study? The water cycle cannot simply provide more and more water to support development. Equally, there is a limit to the amount of wastewater that can be safely returned to our rivers, the sea and groundwater without having a detrimental impact on the environment in terms of water quality. Furthermore, we know that extreme rainfall can overwhelm drains, sewers and watercourses, and cause overtopping of flood defences. Climate change is bringing fresh challenges as patterns of rainfall are predicted to change, with more intense and frequent rainfall events. Consequently planning the timing and location of future development has to take into account these natural constraints associated with the water cycle. A WCS will identify tensions between development proposals, infrastructure provision and environmental requirements and seek to identify potential solutions to address them. The optimum solution for a given locality may be to adjust the location, timing or nature of development. For example, it may be more cost effective to improve the water efficiency of new and existing houses rather than build a new water supply reservoir, or to build houses outside of the floodplain rather than build costly flood protection. Equally the WCS may identify what, and when, new infrastructure is required to support development. A WCS is:

- a method for determining what sustainable water infrastructure is required and where and when it is needed; - a risk based approach ensuring that town and country planning makes best use of environmental capacity and opportunities, and adapts to environmental constraints; - a way for all stakeholders to have their say, preventing any unexpected obstacles to growth; and - the process that brings all the available knowledge and information together to help make better, more integrated, risk based planning decisions.

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1.3.1 County Durham Outline Water Cycle Study This is the County Durham Outline WCS which has assessed potential housing development with regard to the water cycle. The study has considered if the water cycle can accommodate the proposed levels of housing or where further work may be required to facilitate development. A key consideration has been to ensure that housing development does not detrimentally impact upon the water cycle. The following objectives were established for the County Durham WCS;

- ensure future development occurs within environmental constraints, - provide Durham County Council with information concerning the sustainability of development with regard to the water cycle, - identify water cycle infrastructure requirements to support development, and - provide opportunities for more sustainable infrastructure options.

The report has the following structure:

- Chapter 2 presents the potential future housing growth that has been considered, - Chapter 3 reviews housing development with regard to water resources & water supply, - Chapter 4 reviews housing development with regard to sewage treatment, - Chapter 5 reviews water quality and wider environmental constraints on housing development, - Chapter 6 reviews potential constraints to housing development posed by the risk of flooding, - Chapter 7 draws the findings of the previous chapters together and presents the conclusions of the Outline WCS, and - Chapter 8 presents some guidance for developers with regard to Sustainable Drainage Systems (SuDS). 1.4 Partnership A partnership approach is the most efficient means to co-ordinate future development and the impact on the water cycle given that a number of different organisations are involved in the process. These organisations need to work collaboratively to understand the impact of development on the water cycle and to identify and assess options to overcome any issues that are identified. A WCS brings together three Key Partners who must be involved and actively engaged in the process to ensure future development is sustainable and that the necessary infrastructure is in place to facilitate development. Since development is the driver for a WCS, Local Authorities are charged with the responsibility for leading the WCS and providing the relevant information concerning future development. Water companies are responsible for the provision of clean water and disposal of wastewater and are therefore essential to a WCS to appraise the impact of future development on their infrastructure. The Environment Agency’s ‘operational’ role with responsibility for river defences, river structures, development control and water quality makes it a key player in the WCS process. One of the most important benefits of a WCS is that it allows the key organisations to work together in the planning process and builds confidence between parties. It provides each Partner with an indication of future growth aspirations and what potential constraints may exist. The Key Partners involved in the County Durham WCS are:

- Durham County Council, - Northumbrian Water, and - The Environment Agency

Each of the Partners has a vital role to play to ensure the successful delivery of a WCS for County Durham that meets the objectives of each Partner. Input is required from each of the Partners in terms of providing data, reviewing reports and project outputs and steering the direction that the WCS ultimately takes. A lack of participation by any one Partner will affect the quality of the WCS. Table 1.1 sets out what each Partner is required to contribute to the WCS and the benefits that they will get out of it.

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Table 1.1: Roles & Responsibilities Partner Role in the WCS How they inform the What they get out of the WCS WCS

The WCS comprises part of the evidence base for the County Durham Plan, showing how water services and the water environment have been considered during the strategic planning process. The study provides information and assurances that the Council’s development aspirations can be Lead partner responsible Provision of information met with sufficient water infrastructure. The WCS’ Durham for future development and concerning future input to the Infrastructure Delivery Plan (IDP) will County that a partnership development; locations also contribute towards the evidence base. Council approach is adopted. and phasing. The WCS will ensure a joined up approach between land owners, water infrastructure providers and planners during strategic growth and regeneration planning. The WCS will help to ensure that the natural water environment is protected.

An appreciation and understanding of the development aspirations of Durham County Council, learning when development will come Assess if their water Essential partner for the forward, where and its phasing. infrastructure can support WCS responsible for Northumbrian development aspirations; The WCS can inform long term planning, provision of public water Water identify constraints and identifying where and when investment is required. supply and disposal of measures by which they wastewater. An opportunity to comment on the proposed could be overcome. growth to influence the location and timing of future development by supporting proposals or make recommendations for changes.

Support growth and ensure growth is sustainable Essential partner for the Provision of information with regard to the environment. Environment WCS responsible for flood and data concerning the Encourage sustainable development. Agency risk, development control water environment and its and water quality. constraints and limitations. Participate in and prove partnership working to achieve greater efficiencies by working together.

1.5 Links with Other Studies In addition to forming part of the evidence base for the County Durham Plan the WCS has been informed and will be used to inform a number of other studies;

- The County Durham WCS has been undertaken in conjunction with, and informed by, the County Durham Surface Water Management Plan (SWMP). The SWMP was primarily driven by the need to provide a robust evidence base for the County Durham Plan and identified high level solutions to resolve surface water flooding problems.

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- An IDP is being prepared for County Durham which will be a supporting document for the County Durham Plan. The document will include details of the physical, social and green infrastructure identified by Durham County Council and other service providers as being needed to support the delivery of the County Durham Plan. The WCS should be used by the County Council to inform the IDP of the need for additional water infrastructure to support the forecast levels of housing development across the County.

- Another document relevant to the WCS is the Green Infrastructure (GI) Strategy which is currently in preparation but will include a network of multifunctional green space and other relevant land and watercourses, which support the activity, health and well being of local people and wildlife. Future development and growth across County Durham has the potential to play a role in the expansion and reinforcement of the GI networks. The most obvious means of contributing to GI is through the provision of green spaces on the individual development sites and through SuDS which can create water features, although the identification of deficiencies in existing water infrastructure that require intervention may also present opportunities to contribute towards GI. The WCS has also been informed by many other studies which have been referred to throughout the body of the report.

Future Housing Development

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2 Future Housing Development

2.1 Introduction The need for a WCS came about as a result of Durham County Council’s desire for a significant increase in the number and rate of house building. The County Durham Plan; Durham County Council’s key planning document, states the intention to build 27,500 - 29,000 houses across County Durham by 2030. In order to undertake a WCS it is necessary to understand the planned quantum and spatial distribution of where the houses could be developed across County Durham. Durham County Council provided data from their Strategic Housing Land Availability Assessment (SHLAA) which was considered to represent the best available information concerning sites which are likely to be developed for housing. The SHLAA identifies possible development sites (both ‘brownfield’ and ‘greenfield’) and assesses if they are suitable for housing and when any housing could be achieved and delivered. This data has been used to inform the WCS in the knowledge that the SHLAA represents potential development sites which may not come forward in the planning process. It has therefore been appropriate to limit the level of detail with which these sites are assessed; there is no point developing detailed solutions for development that may never occur. Consequently, it will be necessary for the Partners to review the WCS when the planning process starts to identify specific sites, or areas, for development. If there are any new sites that have not been included in this assessment, or sites that have been flagged as potential problems, it may be necessary to revisit the County Durham WCS. It is also important to note that the SHLAA does not provide a comprehensive coverage of all types of development; hospitals, residential homes, employment and leisure facilities are not represented in the data. The WCS is a high level, strategic document which has focused upon housing development since this is where significant changes are forecast by Durham County Council. 2.2 Planning Policy Context within County Durham Following the creation of the County Durham Unitary Authority in April 2009, the Council has commenced the preparation of the County Durham Plan which will be used as a guide to development within the County in the period to 2030/31. The purpose of the County Durham Plan is to set out the levels of development which will be required in the plan period, as well as to identify the broad locations and the specific sites where this development will take place. However, in accordance with national planning guidance, the policies set out in the County Durham Plan are required to be based on a sound understanding of the relevant issues which is informed by a comprehensive evidence base. The WCS for County Durham will play a key part of this evidence base. In terms of allocating sites for development, the County Durham Plan will identify a number of large-scale strategic sites, which are central to achieving the overall strategy for the County. It will also set out specific allocations within Durham, including all large housing sites (the exact site size threshold is undecided at the time of writing). The work undertaken for the WCS will inform the County Durham Plan, including housing allocations and phasing of development. With regard to the total level of new housing proposed, 27,500 - 29,000 homes are to be delivered by 2030/31. This is based on population projections, past delivery rates of housing as identified in the revised Strategic Housing Market Assessment and also by work being undertaken to ensure that housing demand reflects the aspirations for economic growth. However, the exact amount and location of this housing will be determined by the policies and allocations of the emerging County Durham Plan. The SHLAA data that the WCS has considered identifies a potential supply of 36,103 homes between 2011/12 and 2030/31. Therefore the SHLAA data contains sufficient housing numbers to meet the requirement of the County Durham Plan to deliver 27,500 - 29,000 houses in the period. Note the SHLAA data is currently in a state of continuous revision therefore the numbers considered may not be the most up to date, however it does consider considerably more houses than will be delivered by the County Durham Plan. It should be noted that the SHLAA data is suitable for the purposes of undertaking an Outline WCS. If the Outline WCS identifies constraints to development, further work may be required to identify options by which the constraints could be overcome to facilitate development. The development of detailed solutions to constraints ought to be based on development that has some certainty to it. As such further work would be best undertaken alongside the latter stages of site allocations when there is more certainty concerning development sites.

2.3 Housing Development in County Durham: 2011/12 – 2030/31 The following section presents an overview of the SHLAA data provided by Durham County Council.

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The SHLAA data identified parcels of land where housing is considered to be deliverable and an indication of the rates at which houses might be built on each of the sites. The data provided also included a list of strategic sites, which are considered to be important in terms of delivering the County Durham Plan; these are presented in Table 2.1. Table 2.1: County Durham Strategic Sites Settlement SHLAA Reference Location Total Housi ng Capacity 3/DV/03 Auckland Park 320 Bishop Auckland 3/BA/43 268 Woodhouses Farm 3/BA/38 330 4/DU/101 Sniperley 2000 4/DU/102 4/DU/02 4/DU/04 North of Arnison 750 Durham City 4/DU/05 4/DU/104 Sherburn Road 500 4/DU/79 4/DU/110 Mount Oswald 200 4/DU/112 7/NA/130 Cobbler's Hall 500 Newton Aycliffe 7/NA/313 Young Persons' Centre 150 Stanley 1/ST/03 East of Shield Row 250 Peterlee 5/PE/18 North East Industrial Estate 400

Figure 2.1 presents the spatial distribution of potential housing sites across County Durham. In all there are a total of 513 different parcels of land spread across County Durham designated as being capable of delivering the 36,103 houses (Figure 2.1). The size and number of houses that could be built on each site varies between twelve and one thousand during the period.

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Figure 2.1: Potential Housing Sites

Whilst Durham County Council have provided an annual rate of house building per site the timescales over which housing delivery is considered is occasionally broken down into five year blocks in this report. This is because water company funding runs in five year periods known as Asset Management Periods (AMP); AMP5 runs from April 2010 to March 2015, AMP6 from April 2015 to March 2020 and so on. Table 2.2 presents a breakdown of the SHLAA data into the AMP periods covered by the County Durham Plan timescale where there is a notable step change in the number of houses being built between 2015 and 2020. Table 2.2: Phasing of County Durham’s SHLAA Sites AMP5 2010 - 2015 AMP6 2015 - 2020 AMP7 2020 - 2025 AMP8 2025 - 2030 AMP9 20 30 - 203 1 Total 5,993 14,103 8,833 6,550 624 36,103

The SHLAA sites are primarily dispersed across the east of County Durham (Figure 2.1) and housing development will focus on existing urban areas. Whilst there are several SHLAA sites in the west of County Durham their relatively small size means they do not show up clearly on Figure 2.1. Table 2.3 presents 30 settlements across County Durham which are forecast to experience growth in excess of 250 properties over the period to 2030/31. Of these 30 settlements four; Bishop Auckland, Consett, Durham City and Spennymoor will account for 40% of housing development across the County.

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Table 2.3: Settlements Forecast to Grow by more than 250 Houses Settlement Total Units Percentage Settlement Total Units Percentage Anfield Plain 780 2 Murton 618 2 Barnard Castle 309 1 Newton Aycliffe 1,660 5 Bishop Auckland 2,691 7 Pelton 539 1 Bowburn 388 1 Peterlee 1,172 3 Burnhope 260 1 Sacriston 567 2 Chester-le-Street 670 2 Seaham 1,421 4 Chilton 738 2 Shildon 725 2 Consett 3,448 10 Shotton Colliery 319 1 Coundon 464 1 Spennymoor 3,440 10 Coxhoe 514 1 Stanley 1,523 4 Crook 670 2 Thornley 456 1 Durham City 4,830 13 Tow Law 250 1 Easington 725 2 Trimdon 394 1 Fencehouses 330 1 Ushaw Moor 264 1 Ferryhill 630 2 Other 5,016 14 Meadowfield 292 1

This Outline WCS for County Durham presents a high level review of all of the SHLAA data in Figure 2.1 and has tried to give some focus to the strategic sites in Table 2.1.

Water Resources and Water Supply

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3 Water Resources and Water Supply

3.1 Introduction Future growth within the study area would be significantly constrained if there was insufficient water resources available to support the levels of growth and / or if the water could not be supplied to the areas where new development occurred. The following section reviews the current status of water resources and the ability to supply clean water across County Durham. 3.2 Water Resources & the Environment Agency 3.2.1 Catchment Abstraction Management Strategies The Environment Agency manages water resources at a strategic level through Catchment Abstraction Management Strategies (CAMS). Through CAMS, the Environment Agency assesses the availability of water resources, indicating:

- The relative balance between the environmental requirements for water and how much is licensed for abstraction; - Whether water is available for further abstraction; - Areas where abstraction needs to be reduced.

The categories of resource availability status are shown in Table 3.1 below. Table 3.1: CAMS resource availability status categories Indicative Resource Licence Availability Availability Status Water available Water is likely to be available at all flows including low flows. Restrictions may apply. No water is available for further licensing at low flows. Water may be available at high flows No water available with appropriate restrictions. Current actual abstraction is such that no water is available at low flows. If existing licences Over-licensed were used to their full allocation they could cause unacceptable environmental damage at low flows. Water may be available at high flows with appropriate restrictions. Existing abstraction is causing unacceptable damage to the environment at low flows. Over-abstracted Water may still be available at high flows with appropriate restrictions.

CAMS identify Water Resource Management Units (WRMU) and Groundwater Management Units (GWMU) which the Environment Agency uses to assess and classify the status of water resources. CAMS assess how much water can be safely abstracted whilst safeguarding the water environment and groundwater resources both now and in the future. There are three CAMS that cover water resources in County Durham; the Wear 1, Tees 2 and Tyne 3.

Wear CAMS The Wear CAMS area covers the northern half of County Durham and includes the River Wear, River Browney, River Deerness and the River Gaunless. The Wear CAMS has been split into five WRMUs which cover the surface waters, and one GWMU which covers the areas of water underground. The CAMS process undertakes an assessment of the availability of water resources and develops appropriate management strategies to deal with abstraction related pressures. Table 3.2 provides an overview of the existing water resources availability and the target water resource availability at low flows for the Wear CAMS.

1 Environment Agency (2006), The Wear Catchment Abstraction Management Strategy 2 Environment Agency (2008), The Tees Catchment Abstraction Management Strategy 3 Environment Agency (2005), The Tyne Catchment Abstraction Management Strategy

AECOM County Durham Outline Water Cycle Study 18 Capabilities on project: Water Environment

Table 3.2: River Wear CAMS - Water Resource Availability Surface Water / Individual WRMU Target Status: Target Status: WRMU / GWMU Main River Groundwater Status 2012 2018 Upper Wear River Wear Surface Water Water available No water available No water available Middle Wear River Wear Surface Water Water available Water available Water available Lower Wear River Wear Surface Water Water available Water available Water available River River Gaunless Surface Water Water available No water available No water available Gaunless River River Browney Surface Water Water available No water available No water available Browney Magnesian Move towards no Move towards no River Wear Groundwater Water available Limestone water available water available Source: Environment Agency (2006), The Wear Catchment Abstraction Management Strategy The Water Framework Directive (WFD) classification, which is post Wear CAMS (2006), has identified the Wear Magnesian Limestone groundwater body as failing the water balance test. This means that the aquifer is not being replenished to a sufficient extent to support the abstraction licences currently in operation and indicates that the CAMS data is out of date and water is not available. The Environment Agency has an investigation currently underway to address this issue. This same groundwater body also fails the surface water balance test. This means that abstraction pressures are impacting flows in surface watercourses. There are a number of surface water bodies failing for flow which is a supporting element for Good Ecological Status. The Environment Agency has already commenced an investigation to assess the abstraction pressures on the flows in the ephemeral streams which run off the limestone outcrop area to the sea to the east and to inland rivers to the west. Tees CAMS The southern half of County Durham falls within the Tees CAMS and includes the River Tees, River Greta and the River Skerne. The Tees CAMS has been split into two WRMUs covering surface water and one GWMU covering groundwater. The River Skerne WRMU is the only WRMU that falls within the County Durham boundary. This is because the majority of the River Tees has not been assessed due to the regulation of the River Tees by Cow Green Reservoir and Kielder Water. Table 3.3 provides an overview of the existing water resources availability and the target water resource availability at low flows for the River Skerne WRMU. Table 3.3: River Skerne - Water Resource Availability WRMU / Surface Water / Individual WRMU Main River Target Status: 2014 Target Status: 2020 GWMU Groundwater Status Skerne River Skerne Surface Water Water available No water available No water available Source: Environment Agency (2008), The Tees Catchment Abstraction Management Strategy The Environment Agency has undertaken a Stage 1 investigation as part of the WFD process and anticipates from the preliminary assessment that it will fail for flow, indicating that the CAMS data is out of date and water is not available. Tyne CAMS The Tyne CAMS has been split into seven WRMUs covering surface water, however only the Derwent WRMU falls within the County Durham boundary. However, water is also supplied to County Durham from Kielder Reservoir which is abstracted from the Lower Tyne WRMU. Table 3.4 provides an overview of the existing water resources availability and the target water resource availability at low flows for the River Derwent and Lower Tyne.

AECOM County Durham Outline Water Cycle Study 19 Capabilities on project: Water Environment

Table 3.4: River Derwent - Water Resource Availability WRMU / Surface Water / Individual WRMU Main River Preferred Status GWMU Groundwater Status Derwent River Derwent Surface Water Water available No water available Lower Tyne River Tyne Surface Water Water available Water available Source: Environment Agency (2005), The Tyne Catchment Abstraction Management Strategy It is clear from Tables 3.2 – 3.4 that generally there is going to be a move in the status of water resources across County Durham from “water available” to “no water available” and that the CAMS classification for the Magnesian Limestone GWMU and Skerne SWMU are not representative of the current situation and these management units are unlikely to have water available. However the Lower Tyne WRMU, which supplies water to County Durham is forecast to have water available to support growth as are the Middle and Lower Wear WRMUs.

3.2.2 Water Resources Strategy The Environment Agency has produced a Water Resources Strategy, the aim of which is ‘enough water for people and the environment’. The management and use of water and land must be shown to be environmentally, economically and sociably sustainable. The Regional Action Plan for Yorkshire and the North East Region 4 will enable:

- Water to be abstracted, supplied and used efficiently; - The water environment to be restored, protected and improved so that habitats and species can better adapt to climate change; - Supplies to be more resilient to the impact of climate change, including droughts and floods; - Water to be shared more effectively between abstractors; - Improved water efficiency in new and existing buildings; - Water to be valued, and for prices to act as an incentive for efficient use, while safeguarding vulnerable sectors of society; - Additional resources to be developed where and when they are needed in the context of a twin-track approach with demand management; - Sustainable, low carbon solutions to be adopted; - Stronger integration of water resources management with land, energy, food and waste. 3.3 Water Resources & Northumbrian Water Northumbrian Water is responsible for ensuring that there are sufficient water resources available and the operation and maintenance of the potable water supply system within the study area. Northumbrian Water manages water resources across their region through a Water Resources Management Plan (WRMP) 5. The WRMP sets out how they intend to maintain their water resources over a 25 year planning horizon. Northumbrian Water has two Water Resource Zones (WRZ); Kielder WRZ and Berwick WRZ. County Durham falls within the Kielder WRZ which is not forecast to experience a deficit in water resources or water supply in the long term (although the Environment Agency has raised concerns that the WRMP assessment was based upon the 2008 Regional Spatial Strategy and not the subsequent updates). Northumbrian Water has advised that there is almost 200Ml/d available headroom within the WRZ. The River Wear and Tees are regulated by the presence of Kielder Water; northern Europe’s largest manmade lake which has capacity to hold 200,000Ml of water. The Kielder Water Scheme allows transfers to be made between the major north east catchments and allows water resources to be used to a fuller extent if and when needed. The principal objective in the design of the Kielder Scheme was to supplement the water resources of the Tees basin to meet the forecast increase in demand for water, notably for industrial use. Although the forecast industrial demands did not materialise, recent droughts have shown the advantages of a strategic regional resource. Whilst the volume of transfer has been limited, the

4 Environment Agency (2009), Water Resource Strategy, Regional Action Plan for Yorkshire and North East Region 5 Northumbrian Water (2010), Water Resources Management Plan 2010 - 2035

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option of support has allowed cheaper local sources to be used more effectively without placing restrictions on water use. The transfer system also supports the Rivers Wear and Tees to ensure that prescribed minimum maintained flow conditions are met. The water from Kielder that is used to supplement resources elsewhere is abstracted from the Lower Tyne WRMU, which the Environment Agency has classified as; water likely to be available at all flows including low flows (Table 3.4). Kielder Water is not Northumbrian Water’s only water resource; they also abstract groundwater in the south of County Durham. The Environment Agency has indicated that whilst there is currently water available there will be a move towards there being no water available by 2012 (Table 3.2). Therefore, groundwater sources may not be a viable long term resource for Northumbrian Water. However this needs to be counter-balanced against the fact that groundwater, in general, is a more cost effective water supply since it requires less treatment and by being located closer to the point of use minimises infrastructure requirements and consequently leakage. It is therefore recommended that if Northumbrian Water intend to abstract increased volumes of water from the aquifer to supply the housing development that could occur in the south of County Durham, they liaise very closely with the Environment Agency concerning the potential implications of doing so, to avoid upsetting the current balance and causing environmental degradation. 3.4 Water Supply & Northumbrian Water The SHLAA information has been reviewed by Northumbrian Water to determine if their existing water supply infrastructure is able to accommodate the increased flows through the network that would result from increased water resources needing to be supplied to the new housing development. The review found that 75% of the SHLAA sites could be accommodated by the existing water supply infrastructure. The remaining sites would require some investment in the pipe networks to supply water to the proposed housing developments. One of the key reasons given for investment being required is poor water pressure and the need to get water to sites at a higher elevation. Areas where investment would be required include Consett, Annfield Plain and Newton Aycliffe.

Northumbrian Water advised that the need for investment in the water supply network would not prevent or hinder development taking place. The necessary works would be funded through fees obtained by Northumbrian Water from the developer. 3.5 Conclusions It is concluded that there are sufficient water resources available to support housing growth across County Durham. Kielder Water is used to supply water to the County which Northumbrian Water has advised has sufficient spare resource to support the growth. Additionally the Environment Agency’s assessment of water resources corroborates that there are spare resources from Kielder Water and within the Middle and Lower Tees WRMUs. Northumbrian Water has advised that water supply would not be considered to be a barrier to development. Whilst investment may be required in parts of the water supply network to support the housing growth, funding for this would be obtained from the developer.

Sewerage and Sewage Treatment

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4 Sewerage and Sewage Treatment

4.1 Introduction Once households have used water the wastewater must be taken away. This happens via sewerage infrastructure. Northumbrian Water is responsible for the provision of this infrastructure across the study area. In urban areas, surface water (rainwater) and wastewater were historically drained by a single sewer pipe; known as a combined sewer. However more recent developments have installed separate wastewater and surface water systems. Sewer maps have been provided by Durham County Council for areas of County Durham and although they only cover a small percentage of the County, they show an extensive coverage of combined sewer networks in urban areas. In theory, it can be assumed that any new developments are covered by the existing sewerage network if they are on brownfield land. Where brownfield land served by combined sewers is re-developed, Northumbrian Water is seeking to have the wastewater and surface water flows separated where possible. PPS25 and the Building Regulations give priority to surface water being managed through on-site infiltration systems, over first watercourses and then sewers. The Flood and Water Management Act also requires SuDS to be prioritised to deal with surface water on-site. The removal of the surface water flows from the combined sewers will reduce hydraulic overloading of the sewers and allow additional wastewater flows to be accommodated in the sewer network and treated at Sewage Treatment Works (STW). STWs treat wastewater so that the effluent can be discharged back into the natural environment below agreed consent levels. In producing the WCS for County Durham it became apparent that STWs were the key element in terms of planning for future development. There are several STWs across the County which have a limited ability to support future growth, which would place an absolute constraint on a development site being allowed to proceed. In light of this, the Partnership has undertaken a more detailed review of STWs in comparison to the sewerage infrastructure that transfers wastewater to the STWs. 4.2 Sewerage Northumbrian Water’s Business Plan sets out the following actions with regard to sewerage:

- Develop an integrated long term drainage plan - Major programme to address flooding from sewers - Additional cleaning of sewers to reduce flooding from blockages - Increases to sewerage system capacity to cope with new development and population movement - Levels of sewer replacement increased to sustainable levels - Increased ‘real time’ monitoring and management of the sewerage system to aid planning Northumbrian Water has not reviewed the ability of its sewerage infrastructure to accommodate the potential housing development. They advised that they are currently in the process of developing 108 hydraulic models to identify areas at risk of sewer flooding across their area. Approximately 20% of these are likely to cover parts of County Durham. The findings from this work are not expected to be available until December 2012 however interim results may help inform Durham County Council’s IDP. Consequently it is not possible at this time for the WCS to determine if sewerage presents any constraints to growth across County Durham however, Northumbrian Water and Durham County Council will continue to liaise following the completion of the WCS to ensure that any constraints identified in the sewerage networks are used to inform the planning process. Northumbrian Water has provided two key datasets relating to flooding across County Durham related to their assets; extreme and non extreme event hydraulic flooding. Flooding from a rainfall event with an annual probability less than 5% is classified as an extreme event; in the sense that Northumbrian Water’s sewers are not designed to cope with such an event. Northumbrian Water infrastructure ought to be able to accommodate runoff generated by rainfall events with an annual probability greater than 5% without causing flooding. This is often referred to as ‘DG5 flooding’ and the water company will endeavour to undertake works to address these flood events. (Note: in certain locations Northumbrian Water’s sewers will be able to accommodate runoff from events less than 5% however historically this was the key event).

AECOM County Durham Outline Water Cycle Study 23 Capabilities on project: Water Environment

Figure 4.1 illustrates some of the locations that have been affected, or are at risk, by some of the higher concentrations of hydraulic sewer flooding. An instance of flooding is illustrated by a 100m by 100m grid square, instances may lie on top of one another and DG5 flood incidents may lie on top of extreme events. This information has been used as a proxy for identifying broad locations where the sewer infrastructure may struggle to accept additional flows from new housing developments. Figure 4.1: Incidents of Sewer Flooding

The DG5 flood incident data provided by Northumbrian Water contains 183 entries across County Durham and in addition to the 100m by 100m squares provides details of which drainage area the instance occurred in. There are 26 drainage areas across the County which have been affected by DG5 flooding. Of those 26, only two have notable concentrations; 07-D04 and 07-D35 which are located in Chester-le-Street and Durham City respectively. Although it should be borne in mind that Drainage Area size varies significantly and one would expect the larger drainage areas, found in the key urban areas of Chester-le-Street and Durham City, to collect more flood instances. Northumbrian Water is in the process of completing a flood alleviation scheme involving oversized pipes to provide additional storage in the Belmont and Gilesgate areas of Durham City and Durham County Council has undertaken works to improve highways drainage in the area. This has included the provision of additional gullies and de-silting blocked highways drains to manage the risk of flooding. Based on Figure 4.1, north east Durham City is clearly a hotspot for sewer flooding, however there are no SHLAA sites in this part of the City. A similar situation is found in Chester-le-Street where the SHLAA sites are not located near any DG5 flood instances therefore the sewers may not be a constraint to development. In other parts of County Durham such as Bishop Auckland, Stanley and Peterlee there are SHLAA sites in the vicinity of flood incidents which may suggest that the sewer network may struggle to accommodate additional wastewater flows and investment would be required to address the issue. If upgrades were required to the sewerage infrastructure these would be funded by Northumbrian Water, subject to them undergoing a cost-

AECOM County Durham Outline Water Cycle Study 24 Capabilities on project: Water Environment

benefit analysis and prioritisation. This is however a very high level appraisal and it would be more appropriate for a detailed investigation to be undertaken in key areas to avoid piecemeal solutions should several SHLAA sites come forward in an area but at different times. A discussion of the extreme flood events is presented in Section 6.6. 4.3 Sewage Treatment Northumbrian Water’s Business Plan sets out the following actions with regard to sewage treatment:

- Achieve as near as possible to 100% discharge consent compliance by 2015 - Further significant reduction in pollution incidents by 2015 - Reduce sewage litter by customer campaigns and reducing system spills - Further improvements to river & bathing water quality Northumbrian Water provided the catchment areas for each of their STWs which enabled the forecast housing development to be grouped by STW so that the cumulative impact of development could be evaluated per STW. Table 4.1 presents the results of this assessment, providing details of the headroom (spare capacity at the STW in terms of the number of houses), the total number of houses that are forecast to be built within the catchment area and the primary settlements served by the STW. The table also indicates the headroom remaining after all of the forecast development has been accounted for or when the headroom is forecast to run out and how many houses fall outside the existing capacity of the STW. Table 4.1: Sewage Treatment Headroom Status Total Houses Remaining Headroom or Current Headroom STW Name Forecast to Date Headroom Runs Out Settlements Served (Houses) 2030 & Remaining Requirement Aldin Grange North 121 195 2018/19 - 74 Bearpark, Aldin Grange Newton Aycliffe, Shildon, Aycliffe 1,608 2,449 2020/21 - 841 Redworth, Heighington, School Aycliffe Barkers Haugh 679 3,451 2016/17 - 2,772 Durham City Remaining Headroom - Barnard Castle 2,237 309 1,928 Barnard Castle Remaining Headroom - Belmont, Carrville, Moor End, Belmont 8,027 608 7,419 High Shincliffe Remaining Headroom - Birtley, Ouston, Urpeth, Birtley 7,106 568 6,538 Kibblesworth Bishop Auckland, West Bishop Auckland 4,024 3,241 Remaining Headroom - 783 Auckland, High Etherley, Coundon Bishop Middleham 21 40 2029/30 - 19 Bishop Middleham Current – 3 Remaining Headroom - Bowburn Additional 5,000 due 918 4,085 Bowburn, Coxhoe July 2012 Durham City, Ushaw Moor, Browney 480 983 2019/20 - 503 New Bracepeth, Langley Moor, Meadowfield Butterknowle -65 21 2015/16 - 86 houses Butterknowle, Woodland Remaining Headroom - Chester-le-Street, Great Chester-le-Street 2,722 1,078 1,644 Lumley Chilton Lane 377 211 Remaining Headroom - 166 Chilton Lane, South Ferryhill Cockfield 855 91 Remaining Headroom - 764 Cockfield Consett, Hamsterley, Remaining Headroom - Consett 4,788 2,303 2,485 Chopwell, Ebchester, Castleside

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Total Houses Remaining Headroom or Current Headroom STW Name Forecast to Date Headroom Runs Out Settlements Served (Houses) 2030 & Remaining Requirement Cotherstone 45 13 Remaining Headroom - 32 Cotherstone Consett, South Leadgate, Crookhall 343 445 2018/19 - 102 Crookhall Dipton 468 28 Remaining Headroom - 440 Dipton Eastgate 232 50 Remaining Headroom - 182 Eastgate East Tanfield -1,333 1,502 2011/12 - 2,835 houses Stanley, Annfield Plain Edmondbyers 202 5 Remaining Headroom - 197 Edmondbyers Esh Winning 122 38 Remaining Headroom - 84 Esh Winning Ferryhill North Transferred to Tudhoe Mill STW Ferryhill Fishburn 566 114 Remaining Headroom - 452 Fishburn, North Sedgefield Hilton, Ingleton, Headlam, Gainford 117 28 Remaining Headroom - 89 Gainford Peterlee, Easington Colliery, Remaining Headroom - Horden 24,638 3,207 21,431 Wheatley Hill, Wingate, Hesleden, Blackhall Current – 716 Remaining Headroom - Hustledown Additional 3,000 due 1,041 2,675 South Stanley December 2012 Iveston East 205 2 Remaining Headroom - 203 Iveston Kelloe 75 22 Remaining Headroom - 53 Kelloe, Quarrington Hill Knitsley 536 656 2025/26 - 120 Knitsley, Delves Lanchester 440 491 2026/27 - 51 Lanchester, Burnhope Leamside 241 72 Remaining Headroom - 169 West Rainton, Leamside Burnopfield, Rowlands Gill, Lockhaugh 836 113 Remaining Headroom - 723 South Winlaton Crook, Stanley Crook, Witton- Low Wadsworth 1,062 911 Remaining Headroom - 151 le-Wear, Low, Etherley, Witton Park Middleton-in- 90 72 Remaining Headroom - 18 Teesdale Middleton-in-Teesdale New Moors 40 25 Headroom - 15 South Evenwood Pity Me 398 514 2026/27 - 116 Pity Me Nettlesworth, Kimblesworth, Plawsworth 104 13 Remaining Headroom - 91 Plawsworth Pont Transferred to Consett STW North Leadgate Ramshaw 38 148 2014/15 - 110 North Evenwood Sacriston 740 567 Remaining Headroom - 173 Sacriston Satley 189 12 Remaining Headroom - 177 Satley Remaining Headroom - Seaham, South Hetton, Seaham 14,988 2,282 12,706 Haswell, Murton Seaton Carew STW Remaining Headroom - Hartlepool, Blackhall Rocks, 9,057 50 Secondary 9,007 Hart, Elwick Sedgefield, Houghton-le- Spring, New Herrington, Sedgefield 581 202 Remaining Headroom - 379 Shiney Row, Hatton-le-Hole, Easington Lane, Bournmoor Sedgeletch 873 541 Remaining Headroom - 332 Woodstone Village Staindrop 245 90 Remaining Headroom - 155 Staindrop

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Total Houses Remaining Headroom or Current Headroom STW Name Forecast to Date Headroom Runs Out Settlements Served (Houses) 2030 & Remaining Requirement Stanhope 844 68 Remaining Headroom - 776 Stanhope Sunderland Bridge, Croxdale, Sunderland Bridge 49 8 Remaining Headroom - 41 Hett Tow Law 69 250 2015/16 - 181 Tow Law Trimdon Village 531 277 Remaining Headroom - 254 Trimdon, Trimdon Colliery Spennymoor (North Ferryhill, Tudhoe Mill 3,853 3,440 Remaining Headroom - 413 Cornforth, West Cornforth – transfer) University 207 210 2016/17 - 3 Durham City, Elvet Hill West Cornforth Transferred to Tudhoe Mill STW West Cornforth Cowshill, Wearhead, Western 74 35 Remaining Headroom - 39 STW_Area Ireshopeburn, westage, St John’s Chapel Willington 170 269 2017/18 - 99 Willington, Hunwick Windlestone 148 1,141 2014/15 - 993 Chilton, West Ferryhill Witton Gilbert 87 115 2015/16 - 28 Witton Gilbert, Langley Park Wolsingham 233 223 Remaining Headroom - 10 Wolsingham, Thornley

In all there are 59 STWs in Table 4.1 affected by the forecast development. Of these, the existing infrastructure at 42 would be able to accommodate all of the forecast housing development within their catchment. This facilitates the development of 21,264 houses between now and 2030/31 in places such as Bishop Auckland, Peterlee and Seaham. These 42 STWs also collectively have sufficient headroom to support an additional 70,519 houses. As a general rule, there is significant spare capacity in the east of County Durham, around Seaham and Peterlee. There are 17 STWs where the headroom would be exceeded during the period to 2030/31. In these situations the key questions are;

- when will the headroom run out? - how many houses could be built before that time? - when will the STW be able to support more houses? The Northumbrian Water investment cycle is such that investment at these STWs would not be before AMP6, starting in 2015. Therefore of immediate concern are the two STWs which do not have any headroom; East Tanfield and Butterknowle. East Tanfield STW serves part of the urban area of Stanley and surrounding areas and since it has no headroom investment is required to accommodate the forecast additional housing development. Butterknowle is a similar situation, whilst there are only 21 houses forecast within the STW catchment, and the first of these would not be until 2015/16, the STW is already at its volumetric capacity. In light of the current situation development ought to be restricted or prevented in the East Tanfield and Butterknowle catchments until the headroom issues are addressed. Of the other STWs which will exceed headroom if all of the housing development occurs, four (Bishop Middleham, Knitsley, Lanchester and Pity Me) will not reach capacity until AMP8; 2025 – 2030. As such Northumbrian Water has over 10 years, and two AMPs, to plan the necessary investment at these STWs, monitoring house building to determine if investment is required. The remaining STWs (Aldin Grange North, Aycliffe, Barkers Haugh, Browney, Crookhall, Ramshaw, Tow Law, University, Willington, Windlestone and Witton Gilbert) will exceed headroom between 2014 and 2021, assuming development occurs as forecast. Depending on what measures are required at each of the STWs to cater for the housing development and if the development occurs at the forecast rates, development in these catchments may need to be restricted within the current headroom.

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Figure 4.1 illustrates a timeline of which AMP certain STWs will run out of headroom, if housing development occurs as forecast and Figure 4.2 illustrates the STW catchment areas across County Durham with the SHLAA data coloured coded as to whether or not it exceeds the current headroom. Figure 4.1: Timeline of STW Headroom being Reached 40000 AMP5 AMP6 AMP7 AMP8

35000 Aldin Grange North Aycliffe Barkers Haugh 30000 Bowburn Browney BishopMiddleham

Butterknowle Crookhall Knitsley 25000 East Tanfield Tow Law Lanchester

Hustledown University Pity Me 20000

Houses Ramshaw Willington

Windlestone Witton Gilbert 15000

10000

5000

2011_12 2012_13 2013_14 2014_15 2015_16 2016_17 2017_18 2018_19 2019_20 2020_21 2021_22 2022_23 2023_24 2024_25 2025_26 2026_27 2027_28 2028_29 2029_30 2030_31

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Figure 4.2: STWs Headroom

It is apparent from Figure 4.2 that the areas where it may be necessary to manage the rates of development include Durham City, Stanley, Crook and Newton Aycliffe. 4.3.1 Strategic Sites Table 4.2 presents information concerning which STW catchment each of the strategic sites falls within and whether or not development of the site is forecast to be within the existing headroom at the STW.

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Table 4.2: Strategic Sites & STWs SHLAA Settlement No. of Houses STW Comment Reference 320 between 2015/16 3/DV/03 Bishop Auckland STW Within Headroom and 2030/31 Bishop 268 between 2021/22 3/BA/43 Bishop Auckland STW Within Headroom Auckland and 2029/30 330 between 2021/22 3/BA/38 Bishop Auckland STW Within Headroom and 2029/30 1000 between 2014/15 90 Houses within Headroom , 4/DU/101 Barkers Haugh STW and 2029/30 910 Houses exceed Headroom 1000 between 2014/15 90 Houses within Headroom , 4/DU/102 Barkers Haugh STW and 2029/30 910 Houses exceed Headroom 255 between 2015/16 17 Houses within Headroom 4/DU/02 Barkers Haugh STW and 2029/30 238 Houses exceed Headroom 255 between 2015/16 187 Houses within Headroom 4/DU/04 Pity Me STW and 2029/30 68 Houses exceed Headroom 240 between 2015/16 176 Houses within Headroom Durham City 4/DU/05 Pity Me STW and 2029/30 64 Houses exceed Headroom 500 between 2015/16 4/DU/104 Belmont STW Within Headroom and 2029/30 70 between 2011/12 and 67 Houses within Headroom 4/DU/79 University STW 2016/17 3 Houses exceed Headroom 65 between 2011/12 and 4/DU/110 University STW Within Headroom 2016/17 65 between 2011/12 and 4/DU/112 University STW Within Headroom 2016/17 500 between 2015/16 175 Houses within Headroom 7/NA/130 Aycliffe STW Newton and 2029/30 325 Houses exceed Headroom Aycliffe 150 between 2019/20 25 Houses within Headroom 7/NA/313 Aycliffe STW and 2024/25 125 Houses exceed Headroom 250 between 2015/16 Stanley 1/ST/03 East Tanfield STW 250 Houses exceed Headroom and 2022/23 400 between 2020/21 Peterlee 5/PE/18 Horden STW Within Headroom and 2029/30

It is notable from Table 4.2 that the development of the strategic housing sites in Durham City, Newton Aycliffe and Stanley may need to be restricted until sufficient headroom can be provided to support the development. 4.3.2 Addressing the Shortfall in STW Headroom It is essential that Northumbrian Water plan appropriate strategies for STWs in County Durham where significant housing development is going to take place which would exceed the current headroom. If development were to come forward at a rate that exceeded the headroom of any of the STWs, the implication is housing developments having to be delayed until the necessary measures are in place to treat the additional wastewater. At STWs where the headroom would only be exceeded by a small number of houses (e.g. Bishop Middleham; 19, Witton Gilbert; 28) there may be means of freeing up existing headroom, rather than investing in upgrades to the STW. One means is to free up existing headroom at STWs served by combined sewers is to separate the wastewater and surface water flows, so that only the wastewater goes into the combined sewer. Where brownfield land served by combined sewers is re-developed, Northumbrian Water is seeking to have the wastewater and surface water flows separated where possible. Surface water comprises the greatest proportion of volume in the combined sewer therefore removing it will have the beneficial effect of reduce the volumetric flow arriving at the STW, freeing up existing headroom. It will also have the additional benefit of freeing up headroom within the sewer system. A brief review of the SHLAA sites within STW catchments that would have their headroom exceeded by less than 100 houses concluded that the majority of sites were on greenfield, rather than brownfield land. Consequently, separation of combined flows may not be able to play a significant role in freeing up existing headroom. That is not to rule it out completely, it could still play a

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role and retro-fitting SuDS schemes and the identification and removal of mis-connections of surface water sewers and watercourses from the combined sewer network could still provide benefits as part of a suite of measures designed to address headroom shortfalls. Further investigation would be required to identify areas that could be disconnected from the combined sewer system and identify an alternative means of disposing of the surface water, without creating a flood risk. In situations where there is a significant shortfall in headroom it will most likely require investment by Northumbrian Water to upgrade the existing infrastructure or provide new infrastructure to accommodate the forecast housing development. Northumbrian Water is in the process of preparing their supply-demand balance which will inform their Business Plan for AMP6 (2015-2020). The Business Plan will be submitted in 2013 and in August 2014 they will find out if OFWAT supports the Business Plan and influence the size of the capital programme for the period. This in turn, allows OFWAT to set the final determination for price limits for Northumbrian Water. The timing of the WCS is such that the findings are able to feed into the Business Plan for Northumbrian Water to request funding to address the headroom shortfalls in AMP6. In response to the review that has been undertaken for the WCS, a Control Point 0 (CP0) has been raised for each STW where growth will exceed the current headroom. A CP0 means that the STW will be reviewed by Northumbrian Water in terms of growth and the level of investment that might be required, to inform the Business Plan. A strategic CP0 has been raised for all of the five STWs serving Durham City to ensure that growth is addressed holistically rather than piecemeal. An additional driver that can support the Business Plan and STW upgrades is the Environment Agency requiring investment to improve water quality and meet the WFD targets (see section 4.3.4). Two STWs have been identified as already having no headroom available; East Tanfield and Butterknowle. Consequently Northumbrian Water may have to object to development, certainly significant development, until the headroom issues have been addressed. In other situations where the headroom will run out before 2015, or soon after, i.e. before Northumbrian Water has secured funding to start the process of feasibility studies that would eventually lead to investment, it may be necessary to delay or phase development within the existing headroom. The need to delay development would be considered on a site by site / STW basis, depending on when development comes forward with regard to investment timelines. It may be possible for Northumbrian Water and the Environment Agency to agree a temporary relaxation of the STW consent or for temporary kit to be put in place to bolster STW capacity as a short term solution to allow development to occur whilst a long term solution is implemented. In order to address some of the potential shortfalls in headroom Durham County Council and Northumbrian Water are going to work together to direct developers to areas where there is headroom thereby trying to avoid having to restrict growth. A meeting is to be scheduled for autumn 2012 to discuss this further. Equally the two organisations could manage which developments come forward in the planning process, perhaps to facilitate development of the strategic sites at the expense of sites that are considered to be less critical to growth ambitions. 4.3.3 Non-Mains Sewerage Not all houses are connected to the public sewerage system, operated by Northumbrian Water. In areas where there is a public sewerage system the Environment Agency normally insists that new houses connect to it. However, in the more rural, remote areas of County Durham houses are present where there is no public sewer system to connect to. In such circumstances alternative means of disposing of wastewater are required, such as cess pits and septic tanks, often referred to as “non-mains drainage”. Whilst individually such methods of disposal may pose little risk to groundwater or watercourses in terms of water quality and pollution, the cumulative impact of lots of such schemes could be detrimental in the long term. Many of the watercourses in County Durham are failing WFD targets therefore the continued prevalence of non-mains drainage schemes could inhibit attempts to meet WFD targets. Potential policy interventions that could be adopted to mitigate the impact of non-mains drainage include:

- Object to use of cess pits,

- Encourage the use of package treatment plants (private), in favour to septic tanks,

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- Do not consider applications involving the use of non main methods of drainage in areas where public sewerage exists. (In practice, the Environment Agency do not issue permits in such circumstances and would object to applications in principle however, a pro-active approach to this in pre-planning would save the applicant time and money). 4.3.4 Water Quality STWs are regulated by the Environment Agency both in terms of the volume of flow received at the works (which indicates the headroom, considered above) and the treatment performance standards (i.e. the quality of effluent that is discharged). Exceeding either can result in pollution and water quality deterioration. Without investment and managing the timing of development the forecast housing development poses risks of failing the treatment performance standards and consequently the risk of potential pollution incidents at 17 STWs. Northumbrian Water has advised that as a rule treatability issues are easier to manage and resolve than volumetric issues (headroom) and the long term solution is investment by the water company. As such Northumbrian Water would be required to invest in the process streams at Aldin Grange North, Aycliffe, Barkers Haugh, Bowburn, Cockfield, Consett, East Tanfield, Hustledown, Knitsley, Middleton in Teesdale, New Moors, Pity Me, Ramshaw, Tow Law, Tudhoe Mill, Windlestone and Wolsingham STWs to address the risks of failing treatment standards. In situations where the volumetric flow will exceed the permitted limit, i.e. the headroom runs out, Northumbrian Water may seek a variation of their consent from the Environment Agency to be able to discharge a greater volume of treated effluent. This would be particularly true of STWs experiencing significant growth e.g. Barkers Haugh has a shortfall of 2,772 houses. As a general rule, the Environment Agency will impose tighter limits for more flow, and Northumbrian Water will subsequently need to invest to provide sufficient capacity (both volumetric and pollutant removal). In areas where the existing water quality is failing WFD targets, or where the STW discharges to a relatively small watercourse, the restrictions might be onerous. 4.4 Conclusions Of the 59 STWs across County Durham that would be affected by the potential housing development, 42 would be able to accommodate all of the development within the existing infrastructure. This facilitates the building of 21,264 houses between now and 2030 in places such as Bishop Auckland, Peterlee and Seaham. 17 STWs would require investment in the treatment processes to ensure that the effluent discharges stayed within the consented limits to avoid potential pollution and water quality deterioration in the receiving watercourse and 17 would require investment to ensure the headroom was not exceeded. Too much flow arriving at the STW, when the headroom is exceeded, can also cause pollution incidents. Northumbrian Water has raised CP0’s for all of these STWs where growth could exceed the headroom or breach consent licences. This means that they will review the need to apply for funding to address the issues in the next AMP (2015-20). Until this funding is in place, and the necessary feasibility studies undertaken, it will be necessary for Durham County Council, Northumbrian Water and the Environment Agency to work together to manage development. This could involve, but is not restricted to;

- Phase development in line with STW investment timelines,

- Direct developers to areas where there is sufficient headroom,

- Favour development of strategic sites as the expense of other sites,

- Implement temporary arrangements at STWs to facilitate development.

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Water Quality and Other Environmental Considerations

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5 Water Quality and Other Environmental Considerations

5.1 Introduction Water is essential for life, and is vital for our health and wellbeing (potable supplies, disposal of waste water, recreation and amenity), for agriculture, aquatic environments and fisheries, industry and transportation. The water environment, through wetlands and floodplains, can also provide natural water storage and flood protection. Therefore, it is important that this resource is protected and used sustainably and there are numerous European Directives and National Acts that have legislated to that effect, in addition to national and local planning policy. Appendix A provides a review of this legislation. Durham County Council is committed to the holistic management of the water environment. The County Durham Plan will include policies that protect and enhance the water environment, making prudent use of water resources, and encouraging the use of SuDS. The preceding chapter considered if STWs had spare capacity to accommodate additional housing development across County Durham. However, it did not consider if the water environment is capable of receiving increased volumes of treated effluent from STWs. The following chapter provides a review of the potential impacts of potential housing development on the water environment taking issues such as water quality into account. 5.2 The Strategic Water Environment in County Durham This section provides an overview of the strategic water environment in County Durham so as to be able to understand what environmental constraints might exist that could affect housing development and the role that housing development could potentially play to work towards improving the water environment. 5.2.1 Study Area – County Durham County Durham can be divided in two roughly either side of the A68 and A688 between Consett and Barnard Castle. To the west lies the western North Pennines (a rural upland landscape) and to the east is the lowland and more populated coastal plain. There are three main river catchments; the Wear, Tees and Derwent (of the River Tyne). All rise in the North Pennines and flow east, meeting the sea outside of County Durham. The County’s rivers provide an important source of water for domestic, industrial and agricultural purposes, as well as supporting important aquatic ecosystems. The River Wear rises in the North Pennines at the confluence of the Killhope and Burnhope Burns, in an Area of Outstanding Natural Beauty (and the North Pennines Moors Special Area of Conservation and Special Protection Area). It flows east to Bishop Auckland, and then north towards Sunderland and the North Sea. Significant tributaries of the River Wear include the River Deerness and River Browney (Figure 5.1). The River Tees also rises in the North Pennines (to the south of Weardale) and flows in a south-easterly direction towards Barnard Castle leaving County Durham upstream of the A1(M) and Darlington. The River Skerne is a significant tributary of the River Tees and drains a catchment south of Durham towards Darlington, leaving County Durham south of Newton Aycliffe. The upper reaches of the River Derwent and Derwent Reservoir lie along the northern boundary of County Durham between Townfield and Rowlands Gill, with numerous small first and second order tributaries extending within the County boundary.

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Figure 5.1: Main Rivers

5.3 Water Framework Directive Classification The following provides an overview of the classification of water bodies in County Durham under the WFD. It is recommended that Appendix A is read prior to this section to provide the necessary legislative context. Table 5.1 presents a summary of the available water quality classification for all water bodies within County Durham under the WFD.

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Table 5.1: Status objectives for water bodies in the Northumbria River Basin District* (RBD) Status Objective Water Body Less than Good in Total Number of Water Catchment Category Good or High in 2015 Good or High in 2027 2015 Bodies Overall All 147 334 187 334 Tyne 47 82 35 82 Wear 8 47 39 47 Rivers, Canals Tees 15 58 43 58 Total 70 187 117 187 Tyne 1 4 3 4 Lakes and SSSI Wear 2 5 3 5 ditches Tees 1 3 2 3 Total 4 12 8 12 Tyne 23 43 20 43 Heavily Wear 6 24 18 24 Modified Water Tees 14 36 22 36 Body (HMWB) Total 43 103 60 103 Tyne 4 6 2 6 Artificial Water Wear 8 8 0 8 Body (AWB) Tees 17 17 0 17 Total 29 31 2 31 Coastal 1 0 0 1 * The information presented refers to the catchments within the Northumbria RBD that fall within County Durham (Source: Environment Agency Northumbria RBMP, Appendix B Objectives for Waters (December 2009)) Overall, there are 334 water bodies (333 freshwater bodies and one coastal water body) within County Durham of which 134 (40%) are designated as Heavily Modified Water Bodies (HMWB) / Artificial Water Bodies (AWB). It is predicted that 146 water bodies (44%) will achieve at least good status or potential by 2015. It envisaged that the remaining 187 water bodies (56%) will not achieve their good status/potential until 2027. There are a number of reasons for these watercourses not achieving good status by 2015. Key reasons for failures in the status of water bodies within the Northumbria RBD include physical modifications due to control structures, dredging, aggregate extraction, flood risk management and impoundments, as well as recreation, commercial fisheries and urban/transport pressures. Diffuse pollution from agriculture, urban areas and mines, together with point source discharges, also play a key role in determining the status of these water bodies. Annex G of the Northumberland RBMP describes the pressures and risks to the water environment from anthropogenic sources and requires a proactive response to “risks” rather than the reactive response to “impacts.” We have reviewed the Programme of Actions set out in Annex C of the RBMP and relevant measures are listed in Table B1 in Appendix B. 5.3.1 General Quality Assessment Before the implementation of the WFD, the Environment Agency used to monitor water quality using the chemical and biology General Quality Assessment (GQA) method, which targeted the effects of organic pollution. Across County Durham there were 200 chemical (covering 762 km across 64 separate watercourses) and 100 biology monitoring sites (taken from 56 separate watercourses). Table 5.2 provides a summary of the GQA results for County Durham in 2008. Figures 5.2 and 5.3 show the GQA Grades for biology and chemistry respectively.

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Table 5.2: GQA Results for 2008 Chemical GQA Biology GQA

Percentage of Percentage total Percentage of GQA Grade Total stretch Number of Sites total monitoring stretch distance Number of Sites total monitoring distance (km) sites (km) sites

A (very good) 56 28 % 280.7 km 36.8 % 33 33 %

B (good) 78 39 % 297.7 km 39.1 % 26 26 %

C (fairly good) 39 19.5 % 108.4 km 14.2 % 15 15 %

D (fair) 8 4 % 30.7 km 4 % 14 14 %

E (poor) 12 6 % 36.3 km 4.8 % 11 11 %

Unclassified 7 3.5 % 8.2 km 1.1 % 1 1 %

(Source: Environment Agency, 2010) Figure 5.2: GQA Biology

(Source: Environment Agency, 2010)

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Figure 5.3: GQA Chemistry

(Source: Environment Agency, 2010)

In 2008, 67% of chemical GQA monitoring sites covering 76% of the monitored stretch of rivers in County Durham had water that was classed as good or very good. A similar level (59%) of monitoring stations recorded results of good or very good in terms of biological quality (based on invertebrate assemblages sampled over three years and compared against predicted pristine conditions). In terms of GQA results, which reflect the effects of organic pollution, watercourses in County Durham tend to be of good and high quality, but tend to deteriorate in lower reaches. It is worth noting that the lower reaches of watercourses are in the developed east of County Durham where further development is forecast to occur. 5.3.2 Impact of Development on the Water Quality Increasing the population served by a sewerage catchment may lead to water pollution reaching unacceptable levels. This can arise from discharges either from the STWs or from the sewerage system, which may or may not be from intentional combined sewer overflows. The primary impact of excessive discharges is on chemical water quality but this can be reflected in deterioration in the ecology of the receiving water. The WFD aims to achieve and maintain good ecological status. To this end, it establishes standards for water quality parameters, of which those most commonly affected by sewage discharges are for phosphate, ammonia and dissolved oxygen.

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Discharges from sewerage systems and STWs are subject to permission from the Environment Agency who impose conditions on the volume and quality of discharges to ensure, subject to considerations of technical feasibility and disproportionate cost, that the quality of the receiving water complies with the relevant standard. Figure 5.5 illustrates the WFD status of water bodies in County Durham. Within County Durham, - thirteen STWs discharge to water bodies that do not meet the standard for phosphate. Two of these already incorporate treatment to remove phosphate; o Aycliffe o Barkers Haugh o Bear Parl (Aldin Grange) o Bishop Middleham o Bowburn o Browney o Crookhall o East Tanfield o Knitsley o Lanchester o Tow Law o Windlestone o Whitton Gilbert - four STWs discharge to water bodies that do not meet the standard for ammonia; o Bishop Middleham o East Tanfield o Birtley o Windlestone - two STWs discharges to a water body that does not meet the standard for dissolved oxygen; o Bishop Middleham o Chilton Lane This does not necessarily mean that the STWs cause these non-compliances and the Environment Agency is currently undertaking investigations to clarify the causes. The results of these investigations will guide remedial measures, which may include improvements to STWs and / or sewerage systems. These are likely to occur within the second or third cycle of River Basin Management Planning under WFD, i.e. 2015-2021 or 2012-2027. Planning of improvements that may be necessary to ensure that water quality standards are met is the responsibility of Northumbrian Water. The design of improvement schemes and the permit conditions imposed upon them will usually allow for some growth within the catchment. Sewerage and sewage treatment capacity will impose a restraint on development only if more growth occurs than has been allowed for. Aycliffe, Barkers Haugh and East Tanfield will each serve some of Durham County Council’s strategic sites. If improvement schemes are needed now or in the foreseeable future, the timing of and funding for these needs to be factored into Northumbrian Water’s investment planning which is on a five year cycle, with the next review due in 2014.

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Figure 5.5: WFD Status of Water Bodies in County Durham

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5.4 Geology With reference to the British Geological Survey Geological Ten Mile Map Northern Sheet (Solid) scale 1:625 000, the central area around Durham and occupying the lowland plain consists of the Westphalian Formation of the Carboniferous Period, a sedimentary rock described as Coal Measures (a Secondary A Bedrock Aquifer according to the Environment Agency). In the southeast corner of County Durham is Magnesian Limestone of the Permian Period (a Principal Bedrock Aquifer according to the Environment Agency) and in the western edge of the Northern Pennines consists of the Namurian Formation of the Millstone Grit series, a sedimentary rock laid down during the Carboniferous Period. The valleys of the River Wear and Tees have formed in the Tournaison and Viséan Formation of the Carboniferous Limestone Series, with some igneous rock intrusions. Large parts of the County are underlain by porous rock that holds groundwater. The Magnesium Limestone in the east provides a significant amount of water at the regional scale, but there are locally important Secondary Aquifers further west. The geological strata in the central area can hold and transmit water, but this area tends to be contaminated by previous mine workings. The Environment Agency has designated areas around major groundwater abstractions as Source Protection Zones (SPZ). SPZs can be one of three zones depending on the time it takes for water to travel to the point of abstraction, or the percentage of the entire resource (whichever is the greater). The Environment Agency has identified several SPZs on the East Durham Limestone plateaux (Figure 5.6). Some of these sites are at risk from rising contaminated mine waters and leachate from landfills. Figure 5.6 also illustrates the potential development sites with regard to the SPZs. The SPZs are used in conjunction with the Environment Agency’s Groundwater Protection Policy to set up pollution prevention measures in areas which are at a higher risk, and to monitor the activities of potential polluters nearby. 94 SHLAA sites fall within the Source Catchment Protection Zone, of which 21 within the Outer Protection Zone and no sites within the Inner Protection Zone. Developers should have due regard to the SPZs that sites fall in, since it will influence the type of SuDS technique that is appropriate and will be acceptable.

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Figure 5.6: Source Protection Zones

(Source: Environment Agency, 2010) The Magnesian Limestone aquifer (Figure 5.7) extends from South Shields to Darlington and is considered to be the most important groundwater resource within the area, supporting both public supply and industrial abstraction. Whilst the aquifer is an important water resource it also presents a number of environmental constraints that need consideration particularly if Northumbrian Water were to seek to abstract additional water from the aquifer in order to serve the additional housing development planned for County Durham. 148 SHLAA sites lie within the Magnesian Limestone boundary in areas such as Newton Ayclife, Peterlee and Seaham. The following discussion has been informed by the Northumbrian Magnesian Limestone Aquifer Hydrogeological Conceptual Model 6.

6 Environment Agency (2009), Northumbrian Magnesian Limestone Aquifer Hydrogeological Conceptual Model

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Figure 5.7: Magnesian Limestone Aquifer

Water Supply At present, approximately 93% of licensed groundwater abstraction from the Magnesian Limestone aquifer is for public water supply. In addition to Northumbrian Water, Hartlepool Water also has boreholes in the aquifer for water supply. Whilst the area served by Hartlepool Water is outside of County Durham many of its boreholes lie within County Durham in the River Skerne catchment and could be affected if development in County Durham were to negatively impact the aquifer. This is particularly relevant since Hartlepool Water has no sources of water other than boreholes from the Magnesian Limestone aquifer. Since 1982 the water resource of the Northumbrian Water supply area has been dominated by the influence of Kielder Reservoir. It lies at the head of the River Tyne, and discharges water to the Tyne for abstraction at Riding Mill (near Hexham) or in Newcastle. At Riding Mill, water is pumped uphill to a holding reservoir before entering a tunnel. This tunnel is used to distribute water southwards to be put into the Rivers Derwent, Wear or Tees for abstraction downstream if required. Consequently the Magnesian Limestone aquifer does not act as a significant source of water for Northumbrian Water.

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Coal Mining The Magnesian Limestone aquifer is underlain by the Carboniferous Coal Measures. Coal was extracted from beneath the Magnesian Limestone from the mid eighteenth century until the late twentieth century. The presence of mine workings beneath the Magnesian Limestone has had a number of consequences for the groundwater resources in the Magnesian Limestone aquifer. The coal mines were maintained in a dry condition by abstracting considerable volumes of groundwater, a high percentage of which originated as water draining down from the overlying Magnesian Limestone aquifer. This induced a significant amount of drawdown of groundwater levels in the aquifer. On cessation of mining, the mines no longer needed to remain dry and abstraction stopped resulting in water levels rising in the Coal Measures. Where these levels have reached the base of the Magnesian Limestone aquifer, the leakage rates from the Magnesian Limestone have reduced, resulting in a rise in groundwater levels in the Magnesian Limestone aquifer. Since 1975 there has been a rise in groundwater levels of 10m or more. One consequence of this has been a change in the condition of the River Skerne (Figure 5.7), a tributary of the River Tees which flows across the limestone for almost all its length and significant interaction with groundwater occurs. When the groundwater levels were depressed due to abstraction from the coal mines, the River Skerne lost water into the aquifer. Since mining has ceased and groundwater levels have risen, the aquifer is contributing water to the river. A second consequence of the rising water levels in the mines has been the threat of contamination of the Magnesian Limestone aquifer by polluted water from the mines, which has the potential to threaten the viability of a number of public water supply abstractions. This is of key interest in the area north of Newton Aycliffe, where mine water is discharging to the aquifer and appears to have developed a plume of pollution that threatens some of Hartlepool Water’s water sources. However, after a first flush of highly contaminated mine water, the high concentrations appear to be declining and the plume is moving slowly. Work done to date suggests that mine water levels appear to have stabilised in the area, the pollution plume will not reach the water sources for 50 to 150 years and it may be decreasing in terms of its severity. There is only likely to be a risk if mine water levels increase again, but since mine water levels appear to have stabilised it is less likely that this will be the case. Groundwater discharge to the River Skerne may slow the eastward movement of the plume. Whilst the situation appears to be in balance it would appear to be a delicate balance. If the Coal Authority, or either water company were to alter its current pumping regimes it could affect the balance, positively or negatively. Implications for Development Appropriate planning constraints should ensure that groundwater quality will not be adversely affected by the proposed housing development. Durham County Council, in consultation with the Environment Agency should ensure that developers identify potential risks to the groundwater quality from the development through a source-pathway-receptor methodology. If unacceptable risks are identified Durham County Council in consultation with the Environment Agency can ensure that suitable mitigation measures are implemented by the developer. Durham County Council has the powers to enforce such assessments of risk and implementation of mitigation measures through the planning process (PPS23) and Part IIA of the Environmental Protection Act 1990. The risk of pollution to the aquifer may place constraints on the types of SuDS that could be implemented. 5.5 Nature Conservation Areas and Protected Areas The WFD takes into account the requirements of other European Directives, relevant Protected Areas are:

- Sites designated for nature conservation (including Special Areas of Conservation (SAC) and Special Protection Areas (SPA)); - Freshwater fisheries; - Nitrate Vulnerable Zones; and - Water Protection Areas / Drinking Water Protection Areas.

Relevant SACs and SPAs are listed below:

- North Pennine Moor cSAC & SPA - North Pennine Dales Meadow cSAC

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- Castle Eden Dene cSAC - Moor House – Upper Teesdale cSAC - Thrislington cSAC - Durham Coast SAC - Northumbria Coast SPA - Teesmouth and Cleveland Coast SPA

There are 77 river stretches designated as salmonid fisheries in County Durham covering 399 km (including 11 still waters). There are also 27 cyprinid river stretches in County Durham (including nine still waters) covering 75 km. Although not a Protected Area in terms of the WFD, it is also important to consider nationally important Sites of Special Scientific Interest (SSSI) for which there are 88 in County Durham (Figure 5.8). At this stage it is not known which of these sites are water dependent. Figure 5.8: Environmental Designations

(Source: MAGIC, 2010) The North Pennine Moors stretch over the western rural side of County Durham and comprises the most expansive SAC, SPA and SSSI designation in the County. In total there are 88 SSSIs, six SACs and three SPAs in County Durham. These environmental designations are shown in Figure 5.8. No SHLAA sites cross an environmental designation but impacts of the proposed housing and other development within the County Durham Plan are being considered as required by the European Habitats Directive. Of relevance to this study, impacts on European Wildlife sites as a result of changes to water quality and hydrology for water dependant sites are being considered.

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Much of the land to the east of Bishop Auckland and between the A1(M) and the A19 is designated as a Nitrate Vulnerable Zone (NVZ) as is the area between just west of Consett (Muggleswick Common) and Chester-le-Street. Figure 5.9 shows 231 SHLAA sites within the NVZ. Developments that fall within the NVZ should be assessed in terms of their site suitability and potential nitrate impacts on the development, associated watercourses and the surrounding urban area. The Magnesian Limestone groundwater body has been classified as being at poor chemical (qualitative) and quantitative status. It fails good status for the Drinking Water Protected Area (DrWPA) due to nitrate and for the General Chemical Test for chloride, sodium and sulphate due to historical abstraction pressures causing saline intrusion, rebounding minewaters and natural geology. The Magnesian Limestone is “at risk” of failing the DrWPA for sulphate. The existing pollution threat could be further exacerbated by new housing development. Figure 5.9: Nitrate Vulnerable Zone

(Source: MAGIC, 2010)

5.5.1 Water Protection Zones The WFD requires the identification of DrWPAs, which are water bodies that provide more than 10m 3/day potable water or serve more than 50 people. All groundwater bodies in the Northumberland RBMP are DrWPAs. Balderhead, Blackton, Hurry, Selset, Grassholme, Derwent, Hiselhope, Waskerley, Smiddy Shaw and Burnhope Reservoirs are also DrWPAs, as is the lower (freshwater) Wear and middle Tees (between Barnard Castle and Darlington) river sub-catchments (as taken from Figure D.1 of Annex D of the RBMP (Environment Agency, 2009)). Where additional water protection measures are required Safeguard Zones

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(SGZ) may be designated. Finally, under the Water Resources Act 1991 (as amended) Water Protection Zones (WPZ) may be designated where existing measures have failed or are unlikely to prevent failure to meet the WFD objectives. The Environment Agency has assessed the pressures and risks to the groundwater bodies in the North East of England and recommended that there are no suitable candidates for WPZ or SGZ, at present, although this could change in the future. 5.6 Conclusions There are a number of watercourses within County Durham that are currently failing WFD targets and are at risk of not achieving WFD objectives by the end of the first cycle in 2015. The ecology and water quality of some of these watercourses may be failing in part because of discharges from STWs. The Environment Agency has a Programme of Measures to improve the class of these watercourses, which includes reviewing discharge consents and thus are likely to resist any increased loading of pollutants from treated sewage discharges. County Durham is underlain by two groundwater bodies, the Wear Magnesian Limestone and the Wear Carboniferous Limestone and Coal Measures which are at Poor Status (although the quantitative status of the Wear Carboniferous Limestone and Coal Measures is Good). The Magnesian Limestone aquifer is for public water supply and is the most important groundwater resource in the area. Whilst development within County Durham can be supported by water resources from Kielder Reservoir and need not abstract water from the aquifer it will of relevance to development in Hartlepool. There will be a need to address future development proposals and their impact on abstraction rates and impact on the aquifer (such as the inclusion of SuDS and appropriate remediation of sites that are potentially contaminated). It is not anticipated that discharges from STWs will have any impact on groundwater bodies. Where water quality requires improvement, a number of options can be adopted including the use of SuDS, local policies and plans to improve drainage and pollution and ecological enhancements. Developments that fall within an environmental designation, NVZ, or the Magnesian Limestone boundary should be assessed in terms of their site suitability and their potential impacts on the environment, associated watercourses and the surrounding urban area.

Flood Risk

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6 Flood Risk

6.1 Introduction Flood risk to people and property can arise from various different sources, including from rivers (fluvial), tidal, surface water runoff (or pluvial), sewers & drains, culverted watercourses, groundwater, as well as though breaching/overtopping of flood defences and from artificial sources such as canals and reservoirs. The risk of flooding can never be totally removed, however through good planning, management and use of sustainable flood mitigation and drainage approaches, the risk and consequences of flooding in many areas can be managed. All sources of flood risk are considered to be a material planning consideration. Planning Policy Statement 25: Development and Flood Risk (PPS25) is the overarching planning guidance for taking account of flood risk in development. It promotes ‘positive planning at all levels to deliver appropriate sustainable development in the right places, taking full account of flood risk’. The key message is to avoid inappropriate development and to locate development away from flood risk through the Sequential Test. The policies within PPS25 should inform all development documents, so that flood risk is taken into account at all stages throughout the planning process. A number of reports and policies are already in place to encourage sustainable flood risk management both nationally and specific to the study area. The aims are to ensure that existing and future generations can live sustainably alongside the inevitable risk of flooding. This section of the WCS summarises some of the work that has been undertaken to understand the risk of flooding across County Durham. 6.2 Catchment Flood Management Plans The Environment Agency has produced Catchment Flood Management Plans (CFMP) across England and Wales which are strategic documents that seek to understand the factors that contribute to flood risk and to identify and agree policies for sustainable flood risk management for the next 50-100 years. County Durham falls across three CFMPs; the Wear CFMP 7 covers the majority of the County, the southern extremities fall within the Tees CFMP 8, and the northern tip falls within the Tyne CFMP 9. The flood risk management Policy Options developed by the three CFMPs are shown in Figure 6.1.

7 Environment Agency (December 2009), Wear Catchment Flood Management Plan 8 Environment Agency (December 2009), Tees Catchment Flood Management Plan 9 Environment Agency (December 2009), Tyne Catchment Flood Management Plan

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Figure 6.1: CFMP Policies

6.2.1 Wear CFMP

The Durham and Browney sub-area is the notable flood risk hotspot in the CFMP, where the Policy Option is to “Take further action to reduce flood risk”. The CFMP infers that between 200 and 1,000 properties are currently at risk in this sub-area, notably at Lanchester and Durham City. There is the potential for an additional 84 SHLAA sites to be developed by 2030 in the Durham and Browney sub-area. The Upper and Mid Wear sub-area falls under Policy Option 6 – take action with others to store water or manage runoff in locations that provide overall flood risk reduction or environmental benefits, locally or elsewhere in the catchment. The Mid Wear sub-area provides a natural storage area for flood waters reducing the risk of flooding downstream. This sub-area contains 38 SHLAA sites in the Spennymoor and Crook area that could help reduce flood risk in the Durham and Browney sub-area through managing runoff on site. 6.2.2 Tees CFMP The key flood risk areas in the Tees CFMP fall outside County Durham and include Redcar, Hartlepool, Middlesborough, Darlington and Stockton on Tees. Newton Aycliffe is the only urban area within County Durham that the Tees CFMP defines as a flood risk area, showing between 50 and 100 properties at risk from a river flood event with an annual probability of 1%. The majority of the Tees sub-areas within County Durham, including Newton Aycliffe, fall under Policy Option 3 - continue with existing or alternative actions to manage flood risk at its current level. With flood risk expected to increase in the future in these sub-areas without further alleviation measures, any potential developments ought to be located away from these flood risk areas.

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6.2.3 Tyne CFMP The Derwent and Rural Team sub-area is the only sub-area that falls within County Durham and is deemed a low flood risk area which supports its preferred Policy Option - “Reduce flood risk management actions”. The northern parts of Consett and Stanley fall within this CFMP sub-area. 6.3 Strategic Flood Risk Assessment When planning and designing new development, Durham County Council must ensure that the development will not add to and should, where practicable, reduce flood risk. For river and sea flooding, PPS25 uses four Flood Zones to characterise flood risk. These Flood Zones refer to the probability of river and sea flooding, ignoring the presence of defences, and are detailed in Table 6.1. Table 6.1: Flood Zones (Adapted from PPS25, Table D.1)

Flood Definition Zone

1 Low probability (less than 1 in 1,000 annual probability of river or sea flooding in any year (<0.1%))

Medium probability (between 1 in 100 and 1 in 1,000 annual probability of river flooding (1%-0.1%)or between 1 in 200 2 and 1 in 1,000 annual probability of sea flooding(0.5%-0.1%) in any year).

High probability (1 in 100 or greater annual probability of river flooding (>1%) in any year or 1 in 200 or greater annual 3a probability of sea flooding (>0.5%) in any given year).

This zone comprises land where water has to flow or be stored in times of flood. Land which would flood with an 3b annual probability of 1 in 20 (5%), or is designed to flood in an extreme flood (0.1%) should provide a starting point for discussions to identify functional floodplain.

PPS25 should be adhered to in order that new development is steered to Flood Zone 1. Where there are no reasonably available sites in Flood Zone 1, decision-makers identifying locations for development and infrastructure, allocating land in spatial plans or determining applications for development at any particular location should consider sites in Flood Zone 2. This decision should take into account the flood risk vulnerability of land uses and apply the Exception Test if required. Only where there are no reasonably available sites in Flood Zones 1 or 2 should decision-makers consider the suitability of sites in Flood Zone 3, again taking into account the flood risk vulnerability of land uses and applying the Exception Test if required. In 2010 a Strategic Flood Risk Assessment 10 (SFRA) was completed for County Durham, to be used as a planning tool to aid in the location of future development away from areas of high flood risk, therefore allowing Durham County Council to comply with PPS25. Site specific Flood Risk Assessments will be required for individual developments to demonstrate that they have appropriately considered the risk of flooding. The flood zones identified in Figure 6.2 form constraints to development in County Durham.

10 Golder Associates (February 2010). Durham County Council, Strategic Flood Risk Assessment (SFRA) – Level 1.

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Figure 6.2: Flood Zones

Flood Zone 3 is highlighted in blue in Figure 6.2, indicating that limited development should occur in this zone. According to PPS25, only Water Compatible and Less Vulnerable development types should be permitted within this zone, these include shops, restaurants, cafes, waste treatment, mineral workings, water and STWs. Residential development is classified as More Vulnerable, therefore to comply with the Sequential Test this type of development should not be permitted in Flood Zone 3, unless it can pass the Exception Test. None of the strategic sites fall within Flood Zone 3 however there are 27 other SHLAA sites that have part of their site within Flood Zone 3. To pass the Exception Test, residential developments should demonstrate that:

- The development provides a wider sustainability benefit to the community that outweighs flood risk; - The development is on previously developed, or developable land; and - The development will be safe from flooding without increasing flood risk elsewhere.

The majority of SHLAA sites fall outside Flood Zones 2 and 3 and would be considered more sustainable than those in Zones 2 and 3, in terms of flood risk. The effect of climate change should also be taken into consideration when making planning decisions to understand the flood risk throughout the development lifetime. 6.4 Preliminary Flood Risk Assessment The Flood Risk Regulations 2009 transpose the Floods Directive in England and Wales and require Lead Local Flood Authorities (LLFAs), which are County and Unitary Authorities, to assess and manage “local flood risk”. The first stage is for the competent

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authorities to prepare a Preliminary Flood Risk Assessment (PFRA) that considers general flood risk from all sources to enable authorities to proceed to the second stage, which involves identifying areas of significant flood risk (Flood Risk Areas). LLFAs are responsible for assessing risk from local sources of flooding, i.e. surface water, groundwater, ordinary watercourses, canals and flooding from lakes within their areas. Durham County Council has recently produced a PFRA for County Durham 11 which provides information on historic and potential future flood events. It is the first step in a four stage process;

- Undertake PFRA, - Identify Flood Risk Areas, - Prepare Flood Hazard and Risk Maps, and - Prepare Flood Risk Management Plans.

The PFRA has identified that County Durham does not have any Indicative Flood Risk Areas, defined as areas where over 30,000 people are at risk of flooding. The PRFA process is based on a 6 yearly cycle and the next submission is due in 2016. 6.5 Surface Water Management Plan Sections 6.2 and 6.3 dealt with flooding from rivers and the sea, however when considering development surface water flooding is another important consideration. Flooding from surface water presents a risk across County Durham, particularly in the urban areas. Durham County Council and Northumbrian Water hold a number of records relating to surface water flooding and both organisations undertake a significant number of engineering works to alleviate flood problems across County Durham. The SFRA for County Durham undertook hydraulic modelling to define areas at risk of surface water flooding. The Environment Agency has also produced Surface Water Flood Maps which build upon their Areas Susceptible to Surface Water maps. One of the recommendations of the SFRA was for a SWMP to be undertaken for County Durham. A SWMP undertakes to identify and prioritise areas at risk from surface water flooding and how the risk will be mitigated. A SWMP was completed for County Durham in 2011 12 . The Risk Assessment component of the SWMP strategically identified broad locations which are considered to be more vulnerable to surface water flooding which have been called Surface Water Risk Areas (SWRAs). These were identified using a cluster analysis in GIS which looked at the distribution of ‘priority’ datasets to identify correlations and patterns in the data so as to form a cluster, in this case a SWRA. In total 139 SWRAs were created across County Durham (Figure 6.3), the majority of which are located in the eastern part of the County, in and around urban areas. Having identified SWRAs the SWMP ranked them in terms of their relative risk, the prioritisation process sought to address known surface water problems and the largest numbers of people at risk of surface water flooding so that resources can be targeted in these areas. The areas at greatest risk were identified as being: - Durham City, - Newton Aycliffe, - East Stanley, - Bishop Auckland, - Lanchester, - Crook, - Chester-le-Street, and - Burnopfield.

11 Durham County Council (2011). Preliminary Flood Risk Assessment (PFRA) Report. 12 AECOM (2011). County Durham Surface Water Management Plan.

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Figure 6.3: Key Surface Water Risk Areas

The SWMP Options phase considered high level options by which the risks of surface water flooding can be managed and mitigated in nine SWRAs identified by Durham County Council and the Environment Agency. Based upon the findings of the Options a generic Action Plan was developed to cover all of County Durham which lists actions by which the risk of surface water flooding can be managed. A selection of the SWMPs key findings have been reproduced below: - Surface water poses a widespread flood risk across County Durham. - This risk is concentrated in the east of the County and specifically associated with urban areas. - Known flood incidents regularly corroborate predictions concerning extreme flooding. - Development presents the best opportunities to manage the risk of surface water flooding. - Northumbrian Water wishes to limit the volume of surface water entering combined sewer systems. Re-development that manages surface water on site will increase the capacity of the combined sewer networks thereby limiting the risk of sewers surcharging and causing flooding. - Durham County Council should encourage developers to not only address runoff from their site but the potential benefits that can be achieved for the wider area.

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- Several development sites that provide opportunities to manage the risk of surface water flooding have been identified (Table 6.2) - If development sites, situated in areas with a high risk of surface water flooding, are unlikely to come forward in the planning process, the Partners ought to consider using the sites themselves to provide surface water management, water quality benefits and green infrastructure opportunities, for example through the creation of wetlands. Many of the SHLAA sites considered by the WCS, including most of the strategic sites, fall within SWRAs defined by the SWMP, and the four main development areas; Bishop Auckland, Consett, Durham City and Spennymoor all have SWRAs associated with them. As such the SHLAA sites present opportunities to manage and mitigate the risks of surface water flooding both on site and in the wider area. The SWMP identified a number of key SHLAA sites (Table 6.2) with potential to manage the risk of surface water flooding in the SWRAs it reviewed and the planning process should ensure that these opportunities are realised. Appendix C presents all of the SHLAA sites which fall within the Environment Agency’s Flood Map for Surface Water and / or Areas Susceptible to Surface Water maps. As such these sites may present opportunities to manage the overall risk of surface water flooding in their area. Table 6.2: Development sites that provide opportunities to manage the risk of surface water flooding

SHLAA Reference SWRA Greenfield / Brownfield

2/CH/08 CLS3 – Chester-le-Street Greenfield

2/WA/01 CLS3 – Chester-le-Street Greenfield

2/WV/02 CLS3 – Chester-le-Street Mostly Greenfield

3/CR/02 CRO1 – Crook Greenfield

4/DU/107 DC8 – Durham Greenfield

4/DU/71 DC8 – Durham Greenfield

3/SJ/02 RAIL3W – St Johns Chapel Greenfield

3/SJ/03 RAIL3W – St Johns Chapel Greenfield

3/WE/05 RAIL3W - Westgate Both

3/WE/04 RAIL3W – Westgate Brownfield

3/WE/02 RAIL3W – Westgate Both

3/FR/04 RAIL3C - Frosterley Greenfield

3/FR/03 RAIL3C – Frosterley Brownfield

1/ST/03 STA3 – East Stanley Greenfield

Combined sewer networks serve the majority of SWRAs and one of the best ways of managing the risk of surface water flooding in urban areas is to reduce the volume of surface water entering the combined sewer system by managing it on site or disposal to an appropriate watercourse where it will not increase the flood risk. Consequently both Durham County Council and Northumbrian Water require development on brownfield land to separate foul and surface water where possible. SuDS present opportunities by which to manage surface water through re-development. The implementation of SuDS for both existing and proposed developments will be more difficult for some sites than others, particularly smaller sites where it is often assumed that the site is too small for SuDS due to the perception that all systems have a large footprint e.g. ponds. However, it is very unlikely that a site, no matter what size, would not be able to implement some type of SuDS scheme. SuDS are usually feasible for small sites and in the case of County Durham could play a very important role in removing surface water from the sewer system and contributing to sustainable development. If in doubt, developers should contact the Partners for advice on what SuDS types are possible for their site.

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6.6 Northumbrian Water Flood Data Northumbrian Water provided two key datasets relating to flooding across County Durham related to their assets; extreme and non extreme event hydraulic flooding. Flooding from a rainfall event with an annual probability less than 5% is classified as an extreme event; in the sense that Northumbrian Water’s sewers are not designed to cope with such an event. Northumbrian Water infrastructure ought to be able to accommodate runoff generated by rainfall events with an annual probability greater than 5% without causing flooding. This is often referred to as the DG5 flooding and the water company will endeavour to undertake works to address these flood events. (Note: in certain locations Northumbrian Water’s sewers will be able to accommodate runoff from events less than 5% however historically this was the return period of interest). Figure 6.4 illustrates some of the locations that have been affected, or are at risk, from some of the higher concentrations of hydraulic sewer flooding. An instance of flooding is illustrated by a 100m by 100m grid square, instances may lie on top of one another and extreme events may lie on top of DG5 flood incidents. Figure 6.4: Concentrations of Sewer Flooding

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and Durham County Council has undertaken works to improve highways drainage in the area. This has included the provision of additional gullies and de-silting blocked highways drains to manage the risk of flooding. The extreme flood data contains 540 entries across County Durham and in addition to the 100m by 100m squares provides details of which drainage area the instance occurred in, the date of the flooding and an indication of what flooded. The first chronological entry in the data-set is the 17 th November 1997 whilst the most recent is the 4 th November 2010. Whilst there are a large number of entries in the data-set it is by no means spread uniformly across the 13 year period. 127 of the 540 extreme flood events occurred in 2007, all on the 23 rd June, and 301 occurred in 2009, albeit spread over five different days in June, July and August of that year. As a result of 2007 and 2009 containing 79% of the extreme flood events the other years covered by the data-set contain relatively few entries with four years not recording any entries and another four only one entry. 6.7 Conclusions 27 SHLAA sites fall within the Environment Agency’s Flood Zone 3. These 27 sites have a potential yield of 1,440 houses, therefore if they were not developed, on the basis of flood risk, there would still be sufficient development sites elsewhere to achieve the 27,500 - 29,000 target in the County Durham Plan. That is not to say that flood risk alone is sufficient grounds not to develop the sites in question since the site may pass the Exception Test and there may be other factors to take into consideration. There is a good understanding of the risk of flooding across County Durham and many of the SHLAA sites, include the strategic sites will present opportunities to manage the risk of flooding, particularly from surface water.

Conclusions

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7 Conclusions

7.1 Introduction This Outline WCS for County Durham has assessed the potential growth that could occur in response to the County Durham Plan committing to significant housing growth. SHLAA data was identified as providing the best available information concerning future growth which identifies potential housing sites well in excess of the 27,500 – 29,000 new properties forecast in the County Durham Plan. The Outline WCS has undertaken a high level review concerning the potential development sites with regard to different aspects of the water cycle and should be reviewed and updated by the Partners as planning data evolves and additional information becomes available. 7.2 Water Resources & Supply Northumbrian Water is responsible for the provision of water resources and the supply of clean water across the study area. County Durham falls within the Kielder WRZ which has available headroom of 200Ml/day which is capable of being utilised to support the housing growth forecast. Investment may be required in parts of the water supply network to support the housing growth, however funding for this would be obtained from the developer. Consequently water resources and water supply are not considered to pose constraints to development in County Durham. 7.3 Sewerage and Sewage Treatment Northumbrian Water has not reviewed the ability of its sewerage infrastructure to accommodate the potential housing development. They are currently in the process of developing 108 hydraulic models to identify areas at risk of sewer flooding across its area. Approximately 20% of these are likely to cover parts of County Durham. The findings from this work are not expected to be available until December 2012 and consequently it is not possible for the WCS to determine if sewerage presents any constraints to growth across County Durham however, Northumbrian Water and Durham County Council will continue to liaise following the completion of the WCS to ensure that any constraints identified in the sewerage networks are used to inform the planning process. 59 STWs have been identified across County Durham that would be affected by the potential housing development. Of these, 42 would be able to accommodate all of the development within the existing infrastructure. This facilitates the building of 21,264 houses between now and 2030/31 in places such as Bishop Auckland, Peterlee and Seaham. 17 STWs would require investment in the treatment processes to ensure that the effluent discharges stayed within the consented limits to avoid potential pollution and water quality deterioration in the receiving watercourse and 17 would require investment to ensure the volumetric headroom was not exceeded. Too much flow arriving at the STW, when the headroom is exceeded, can also cause pollution incidents. Northumbrian Water has raised CP0’s for all of these STWs where growth could exceed the headroom or breach consent licences. This means that they will review the need to apply for funding to address the issues in the next AMP (2015-20). Until this funding is in place, and the necessary feasibility studies undertaken, it will be necessary for Durham County Council, Northumbrian Water and the Environment Agency to work together to manage development. This could involve, but is not restricted to;

- Phase development in line with STW investment timelines,

- Direct developers to areas where there is sufficient headroom,

- Favour development of strategic sites as the expense of other sites,

- Implement temporary arrangements at STWs to facilitate development.

Given the current situation it will be necessary to restrict development in Butterknowle and Stanley, and may be necessary to limit, or closely control development in Durham City, Newton Aycliffe, Tow Law and Crook. 7.4 Water Quality and Environmental Considerations There are a number of watercourses across County Durham that are currently failing WFD targets and are at risk of not achieving WFD objectives by 2015. The reason for the failures may in part be because of discharges from STWs. The Environment Agency has a Programme of Measures to improve these watercourses, which includes reviewing discharge consents and thus is likely to resist any increased loading of pollutants from treated sewage discharges.

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County Durham is underlain by two groundwater bodies, the Magnesium Limestone and the Coal Measures which are at Poor Status (although the quantitative status of the Wear Carboniferous Limestone and Coal Measures is Good). The Magnesian Limestone aquifer is used for public water supply and is the most important groundwater resource in the area. There will be a need to address the future development proposals and their impact on abstraction rates and impact on the aquifer (such as the inclusion of SuDS and appropriate remediation of sites that are potentially contaminated). It is not anticipated that discharges from STWs will have any impact on groundwater bodies. Developments that fall within an environmental designation, NVZ, or the Magnesian Limestone boundary should be assessed in terms of their site suitability and their potential impacts on the environment, associated watercourses and the surrounding urban area. Environmentally important sites should not pose a barrier to future development across County Durham since none of the potential development sites share boundaries or impinge on environmentally designated sites. All of the potential development sites across County Durham have the potential to contribute to wildlife corridors and other GI infrastructure thereby increasing the biodiversity and amenity value of the urban environment. The incorporation of green roofs, ponds and open areas to development sites will provide wider environmental benefits. 7.5 Flood Risk Management Flood risk is not likely to present an insurmountable barrier to future development, although it will need to be taken into consideration prior to development. Information is available concerning flood risk in the form of SFRAs, CFMPs, Flood Zones, the PFRA and SWMP. Whilst only a small proportion of SHLAA sites fall within areas at risk it will still be necessary to ensure that site specific FRAs are undertaken in line with PPS25 as appropriate. PPS25 requires Local Planning Authorities to adopt a risk-based approach to development in areas at risk of flooding, and to apply a sequential test to such areas. This means that, other factors being equal, the planning authority would favour development in areas with a lower flood risk. 7.6 Summary The study has revealed that there is insufficient sewage treatment capacity to accommodate all of the potential growth and in order to do so upgrades to infrastructure will be required across County Durham but it will also be necessary to manage the phasing and location of development.

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Guidance for Developers - SuDS

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8 Guidance for Developers - SuDS

8.1 Introduction This section is intended to provide some general guidance concerning SuDS and how they can contribute to ensuring that further housing development across County Durham is sustainable and does not compromise the water cycle. The implementation of SuDS will be more difficult for some sites than others, particularly smaller sites where it is often assumed that the site is too small for SuDS due to the perception that all systems have a large footprint e.g. ponds. However, it is very unlikely that a site, no matter what size, would not be able to implement some type of SuDS scheme. SuDS are usually feasible for small sites and could play a very important role in contributing to sustainable development across County Durham. SuDS are relevant for all types and scales of housing development particularly sites less than one hectare, in Flood Zone 1 where SuDS are often not considered because a Flood Risk Assessment is not required. If in doubt, developers should contact the Environment Agency or Northumbrian Water for advice on what SuDS types are possible for their site. The WCS is not intended to provide detailed technical design guidance but rather provide an overview of the role that SuDS can play in sustainable development. Detailed information concerning SuDS can be found in a variety of publications including The SuDS Manual, CIRIA 697. Government guidance promotes the use of SuDS to reduce pollution thereby protecting receiving water quality, contribute to biodiversity and GI and to provide protection against flooding. Consequently through the provision of SuDS, developers have the ability to significantly contribute towards sustainable development. In County Durham, appropriate SuDS will be required whenever practicable. Under the Flood and Water Management Act County Councils and Unitary Authorities will become responsible for approving and maintaining SuDS. 8.2 What are SuDS? SuDS are defined by CIRIA as “a sequence of management practices and control structures designed to drain surface water in a more sustainable fashion than some conventional techniques.” According to The SUDS Manual (CIRIA C697, 2007) the principle of SuDS is to “replicate, as closely as possible, the natural drainage from a site” with the objective to “minimise the impacts from the development on the quantity and quality of the runoff, and maximise amenity and biodiversity opportunities.” Table 8.1 presents some of the different aspects of the water cycle that different SuDS techniques have the ability to benefit through the management of surface water.

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Table 8.1: Benefits of SuDS Benefit Description

Flooding The most common application of SuDS in the UK is to manage surface water runoff from a development site through a reduction of runoff volumes and a reduction in runoff rates.

Water Quality / Numerous pollutants including oil, sediments, fertilisers, pesticides, animal waste and litter can be Pollution sourced from urban environments which can cause diffuse pollution or get washed into sewers and watercourses through surface water runoff. Some SuDS designs can provide various levels of water quality improvements by reducing and capturing sediments and contaminants from urban runoff, which can then be removed after settlement or allowed to break down through biological actions.

Biodiversity / Green SuDS can provide environmental benefits by creating habitats which improve biodiversity, contribute to Infrastructure green infrastructure, and improve the amenity of the environment as well as adding an aesthetic quality.

Water Resources Some SuDS designs can recharge groundwater aquifers or allow rainwater to be harvested for non- potable domestic use and for garden irrigation thus reducing demand for water resources.

Community and SuDS can improve the quality of life within a community by providing an attractive environment and Recreation provide areas for recreation.

Education SuDS can provide an attractive educational environment but can also be used to improve the understanding of water and the natural environment.

Benefits for SuDS can provide the opportunity to reduce construction and maintenance costs as well as increase Developers property values where attractive, open green space provides greater amenity value to an area.

Although SuDS are now commonly considered an essential component of new development drainage systems, the focus has remained on the attenuation of flow, rather than on maximizing the treatment potential or the aesthetic qualities that some SuDS techniques offer. However, the implementation of the WFD has shifted the emphasis from water quantity towards water quality. Further, the Floods and Water Management Act 2010 encourages the preferential use of SuDS providing the mechanism for their long term maintenance. SuDS are therefore an essential component of sustainable housing development, as well as a key mechanism to protect and enhance the natural water cycle by preventing adverse impacts from diffuse water pollution, maintaining or restoring natural flow regimes, improving water resources, and enhancing amenity. 8.3 Selection of Appropriate SuDS Surface water runoff should be managed wherever possible in small, cost-effective and complimentary SuDS components, built into a development site’s landscape features, so that runoff is attenuated and treated in incremental steps rather than in large “end of pipe” systems; this concept is known as the “management train”. Within a single management train SuDS features can be categorised into two broad types – infiltration SuDS, which permit the transfer of runoff into the ground, and detention SuDS, which store water temporarily before conveying it downstream to a discharge point into a water body. There are a range of contaminants in diffuse urban pollution that can lead to chronic water quality effects and aesthetic degradation. It is important to tailor the SuDS management train (the number of components of which depends on the risk to the water environment) so that they are effective in treating the pollutants of concern. It is also important to ensure that the SuDS technique is viable on the site and the design criteria should be carefully reviewed when determining the best drainage option. The Building Regulations 2000 Approved Document H: Drainage and Waste Disposal sets out a hierarchy for the drainage of surface water runoff. Surface water drainage should discharge to a soakaway or other infiltration system where practicable. Where this is not possible, runoff may be discharged to a watercourse under consent from the Environment Agency. Where discharge to an infiltration system and watercourse is not practicable, discharge can be made to a sewer. SuDS provide the drainage pathway to attenuate and treat runoff in accordance with this discharge hierarchy. Infiltration SuDS are best suited to areas overlain by permeable soils, drift and geology. Some examples of these SuDS techniques are permeable paving, soakaways, infiltration trenches, infiltration basins and swales. In parts of County Durham, the soils and geology are of a high permeability and may be suitable for infiltration techniques although local factors such as the

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presence of the Magnesian Limestone aquifer will require consideration. Due to the variability of soils and geology however, site specific infiltration tests should be carried out to confirm the feasibility of infiltration drainage. Where infiltration is into an aquifer the risk of contamination should be assessed and minimised, particularly when the groundwater is a source of public water supply. SPZs are used to protect groundwater resources from pollutants. In areas designated as SPZs, the location and type of discharges into the water environment are closely controlled. The level of control is most stringent close to the point of abstraction. Figure 5.5 shows the location of SPZs across County Durham. The SuDS approach is not dependent on infiltration, it also includes attenuation techniques such as ponds, wetlands, green roofs and water recycling schemes which hold back runoff volumes and rates and allow water reuse. 8.3.1 Application of Infiltration SuDS in County Durham

Durham County Council’s Core Evidence base Technical paper 10 (Water) (April 2009) confirms the variability in the potential for infiltration SuDS across the county: 1. Low potential where there is a predominance of low permeability soils (or peaty soils); 2. Medium potential in freely draining loamy soils in Teesdale; 3. Restricted areas of moderate potential are associated with sandy soils in the areas around Hamsterley Forest, and with glacial sand and gravel deposits in the Wear Valley between Stanhope and Walsingham; 4. In the North of the County, most significant areas of moderate infiltration potential are associated with extensive sand and gravel deposits north and east of Durham City; and 5. In eastern part of the County, high SuDS potential is associated with freely draining soils developed directly over major aquifer bedrock on the Magnesian Limestone escarpment.

The Level 1 SFRA for County Durham (Golder Associates, 2010), Chapter 7, included a high level assessment of the potential use of SuDS. It referred to soils, groundwater, topography and catchment area as key issues, but focused the strategic assessment on County wide topography and geology only. A summary of the findings of the report are provided in Appendix D. Future development sites should incorporate SuDS where possible to mitigate the propensity of development to generate additional runoff and reduce flood risk to downstream areas. SuDS can be easily incorporated into future developments to provide an aesthetic urban environment and making the most of benefits of GI for flood storage. 8.4 Different Types of SuDS There are a wide variety of different types of SuDS that can be applied to different sites in different settings. Combinations of the different types should be used to make up the management train for each site. For brevity the most common SuDS are introduced in Table 8.2 by way of an introduction to what is available. More information on each of these can be found in the SuDS Manual, CIRIA C697.

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Table 8.2: Common SuDS

SuDS Type Photo

Source Control

Green Roofs

Green roofs comprise a multilayered system that covers the roof (or walls) of a building with vegetation over a drainage layer.

Green roofs are suitable for most developments.

Rainwater Harvesting

Rainwater harvesting is the collection and storage of rainwater from roofs and other hard surfaces.

Rainwater harvesting systems can be used for residential, commercial and industrial developments.

Water Butts

Water butts are a common means of harvesting rainwater for garden use via an inlet connected to roof downpipes.

Water butts are best suited to low and medium residential development where the catchment area is limited to the property and ancillary building roof area.

Permeable Pavements

Permeable pavements allow rainwater to infiltrate through the surface and into under-layers where it is temporarily stored before infiltrating into the ground, or released to a watercourse or drainage system.

Permeable pavements can be used for a wide variety of developments.

Soakaways

Soakaways store rapid runoff from a single development and allow it to infiltrate into the surrounding soil.

Soakaways are not suitable where there is a risk of contamination, where there are unstable ground conditions and where there are poor draining soils. Field investigations are required to determine infiltration rates.

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SuDS Type Photo

Site Control

Filter Strips

Filter strips are vegetated strips of land designed to accept runoff and allow it to infiltrate or be filtered by vegetation before being received by a stream or surface water collection system.

Filter strips are considered to have a large land requirement, and are not suitable for significant attenuation or if there is risk of ground contamination.

Trenches

Trenches are shallow excavations filled with rubble, stone or other void media that create temporary subsurface storage for runoff. There are two types of trenches; filtration trenches are used where soils are impermeable or where the groundwater is vulnerable to pollution and infiltration trenches filter runoff through the stone media and infiltrate it into permeable soils.

Swales

Swales are linear vegetated drainage systems where surface water can be stored to allow infiltration, and/or conveyed to other SuDS components, a stream or river.

This type of SuDS design can be used in a wide variety of situations where catchments have small impermeable areas.

Bioretention

Bioretention areas, filters or rain gardens are shallow landscaped depressions designed to capture, filter and treat surface water.

Bioretention areas are suitable for various development types including residential plots, car parks, along highways and roads, commercial, and industrial sites and can be retrofitted into existing developments and used where the groundwater is vulnerable.

Geocellular / Modular Systems

Geocellular systems are high void structures which are below ground and used to infiltrate or store runoff before it is discharged to a downstream drainage system.

They can be used for a variety of development types including residential, commercial and

industrial developments. This type of system can be used where there are contaminated sites.

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SuDS Type Photo

Regional Control

Infiltrations Basins

Infiltration basins are vegetated depressions that store runoff for infiltration into the subsurface soil.

The suitability of a site must be confirmed by geotechnical investigations.

Detention Basins

Detention basins are dry basins which temporarily store runoff by use of a controlled release which attenuates flow.

Detention basins are suitable for use on at a variety of development types including residential, commercial, industrial, contaminated sites and where there is high density infrastructure.

Ponds

Ponds are basins which have a permanent pool of water.

Ponds can generally be used for most types of developments and redevelopments for both residential and non residential areas.

Wetlands

Wetlands are constructed shallow marsh systems covered almost entirely by aquatic vegetation.

Wetlands are suitable for residential, commercial and industrial developments.

8.5 Summary With a variety of SuDs techniques that can be considered for a new development, Table 8.3 outlines the capability of different SuDS techniques and their suitability in terms of providing environmental and water quality benefits. SuDS should be considered on a site-by-site basis to facilitate their effective implementation. Guidance on the planning, design, construction, operation and maintenance of SuDS is detailed in CIRIA’s SuDS Manual.

AECOM County Durham Outline Water Cycle Study 67 Capabilities on project: Water Environment Table 8.3: Capability of different SUDS techniques (Extract from CIRIA C697, Table 1.7) Environmental Management Train Suitability Water Quantity Water Quality Benefits

Technique Description Ecology Amenity Filtration Detention Infiltration Aesthetics Prevention Adsorption Nitrification Site Control Conveyance Conveyance Precipitation Volatilisation Pre-treatment Sedimentation Source Source control Biodegradation Uptake Uptake by plants Regional Control Water Water Harvesting

Water butts, site layout Good housekeeping and design practices. ■ ▲ ■ ▲ ▲ ■ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ ▲ and management Pervious pavement Allow infiltration of rainwater into underlying construction/soil. ■ ■ ▲ ■ ■ ▲ ■ ■ ■ ■ ■ ▲ ▲ ▲ Filter drain Linear drains/ trenches filled with a permeable, often with a ■ ■ ▲ ■ ■ ■ ■ ■ ■ perforated pipe at the base of the trench. Filter strips Vegetated strips of gently sloping ground designed to drain water from impermeable areas and filter out silt and other ■ ■ ▲ ▲ ▲ ■ ■ ■ ■ ▲ ▲ ▲ particulates. Swales Shallow vegetated channels that conduct and/or retain water (and can permit infiltration when underlined). The vegetation ■ ■ ■ ■ ■ ▲ ■ ■ ■ ■ ▲ ▲ ▲ ▲ filters particulates. Ponds Depressions used for storing and treating water. They have a permanent pool and bankside emergent and aquatic ■ ■ ■ ▲ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ vegetation. Wetlands As ponds, but the runoff flows slowly but continuously through aquatic vegetation that attenuates and filters the ▲ ■ ■ ▲ ■ ▲ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ flow. Shallower than ponds. Detention Basin Dry depressions designed to store water for a specified ■ ■ ■ ■ ▲ ▲ ■ ■ ▲ ▲ ▲ retention time. Soakaways Sub-surface structures that store and dispose of water via ■ ■ ■ ■ ■ infiltration. Infiltration Trenches As filter drains, but allowing infiltration through trench base ▲ ■ ■ ▲ ■ ■ ■ ■ ■ ■ and sides. Infiltration basins Depressions that store and dispose of water via infiltration. ■ ■ ■ ■ ■ ■ ■ ■ ▲ ▲ ▲ Green roofs Vegetated roofs that reduce runoff volume and rate. ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Bioretention areas Vegetated areas for collecting and treating water before ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ discharge downstream, or to the ground via infiltration. Sand filters Treatment devices using sand beds as filter media. ■ ■ ▲ ■ ▲ ■ ■ ■ ■ ■ Silt removal devices Manhole and/or proprietary devices to remove silt. ■ ■ Pipes, subsurface Conduits and their accessories as conveyance measures storage and/or storage. Water quality can be targeted using ■ ■ ■ ■ ▲ ▲ ▲ sedimentation and filter media.

Key ■ Recommended ▲ Some opportunities, subject to design

Appendices

AECOM County Durham Outline Water Cycle Study 69 Capabilities on project: Water Environment

Appendix A: Water Quality Legislation Review

Water Framework Directive The aim of the WFD is to prevent further deterioration and protect and enhance the status of aquatic ecosystems and associated wetlands, promote sustainable water consumption, and contribute to mitigating the effects of floods and droughts. The WFD was transposed into law in England and Wales by the Water Environment (Water Framework Directive) Regulations 2003. These regulations implement a holistic approach to the management, protection and monitoring of the water environment. The key objectives of the WFD are to prevent deterioration in the status of water bodies and aim to achieve good ecological and chemical status/potential (including quantitative status in groundwater bodies) by 2015. Water bodies must also comply with standards and objectives of Protected Area (i.e. an area designated under another European Directive, such as an SAC or SPA) where these apply. In addition, under the WFD emissions of priority substances must be reduced and emissions of priority hazardous substances prevented. Finally, action must be taken to reverse any identified sustained upward trend in pollution concentrations in groundwater bodies. The actions (or measures) required to ensure that all the water bodies achieve their WFD objectives are set out in a series of statutory River Basin Management Plans (RBMPs) published in December 2009 by the Environment Agency. County Durham is covered by the Northumberland RBMP. Preventing Deterioration in Status or Potential Deterioration in WFD terms refers to a change between status classes – for example, from high to good status or from moderate to poor status. Preventing deterioration in status is a strict requirement of the WFD. For water bodies other than those at ‘high status’, there is only one possible exception to this requirement. This is the situation where physical modification to the water body is required to support certain sustainable human activities (including flood defence) and where a number of criteria set out in the Directive are met (See Section 1.2.2.6). Meeting the ‘Aim to Improve’ Objective If a water body is not already at good status, the RBMP may set out the measures required to achieve good status or it may set an alternative objective for the water body (which must be justified on grounds of technical feasibility or disproportionate cost). It is important to take these measures into account in the WCS to avoid conflicts that could prevent any intended improvements being realised and to resolve any such potential conflicts; to identify whether other measures could be taken to help improve status in failing water bodies. WFD Objective for Groundwater Bodies Groundwater bodies are classified in terms of their chemical (quality) and quantitative status, in addition to an indication of trend. There are only two classes for groundwater status – good and poor, the outcome being set at the lower of either chemical or quantitative status. The specific criteria that must be met for a groundwater body to be classed as being at good quantitative status and good chemical status are set out in the WFD and further elaborated in the Groundwater Directive (2006/118/EC, (replacing 1980/68/EC)). These criteria have been developed in the UK into a series of tests, which are triggered when a relevant risk is identified (i.e. the identification of a risk leads to investigations to determine whether or not the criteria specified in the test are met). Achieving Objectives for EU Protected Sites The WFD identifies areas requiring special protection under other EC Directives (which will also be taken into account where necessary) and water used for the abstraction of drinking water as protected areas. Under Article 4 of the Directive, Member States are required to achieve compliance with any standards and objectives set for each protected area by the end of 2015 unless otherwise specified in the other EC Directive. Article 4.7 Article 4.7 provides a mechanism whereby the objectives of the Directive may not be achieved if this is a result of new modifications and / or new sustainable human activities, and providing the following conditions are met:

AECOM County Durham Outline Water Cycle Study 70 Capabilities on project: Water Environment

- All practicable steps are taken to mitigate the adverse impact on the status of the water body;

- The reasons for those modifications or alterations are specifically set out and explained in the RBMP, required under Article 13 and the objectives are reviewed every 6 years;

- The reasons for those modifications or alterations are of overriding public interest and / or the benefits to the environment and to society are outweighed by the benefits of the new modifications or alterations to human health, to the maintenance of human safety or to sustainable development; and

- The beneficial objectives served by those modifications or alterations of the water body cannot for reasons of technical feasibility or disproportionate cost be achieved by other means, which are a significantly better environmental option.

The WFD requires that effects on water bodies do not cause deterioration nor do they lead to the prevention of a target being achieved, although under certain circumstances there can be exceptions (using Article 4.7). There is also the possibility that the status of a watercourse may change to a modified status, and vice versa, although this would depend on the degree of change relative to the size of the water body. The Flood and Water Management Act 2010 The Flood and Water Management Act 2010 intends to provide better, more comprehensive management of flood risk for people, homes and businesses. It will also help ensure continuity of water supplies. In particular, it encourages the uptake of SuDS by removing the automatic right to connect to sewers and providing for unitary and county councils to adopt SuDS for new developments and redevelopments. The Water Resources Act 1991 (as amended) It is an offence under Section 85 of the Water Resources Act 1991 to cause or knowingly permit pollution of controlled waters. Controlled waters include all watercourses (drainage ditches, streams, rivers), canals, lakes, estuaries and groundwater. The Water Resources Act also makes provision for the consenting (by the Environment Agency) of discharges of potentially polluting substances and the licensing of water abstractions (amended by the Water Act 2003). Both the consenting of discharges and the abstraction of water from waterways have implications for future water quality and the aquatic environment. Future Water The Government’s water strategy for England, Future Water was published in February 2008. This strategy sets out the Government’s long-term vision for water and the framework for sustainable water management in England. It aims to permit the supply of secured water supplies whilst ensuring an improved and protected water environment. Future Water brings together the issues of water demand, water supply, water quality in the natural environment, surface water drainage, river/coastal flooding, into a single coherent long term strategy, in the context of the need to reduce greenhouse gas emissions, and also considers the issue of charging for water. The water environment and water quality have great economic, biodiversity, amenity and recreational value, playing an important role in many aspects of modern day society, and thus the functions provided must be sustainably managed to ensure they remain available to future generations without compromising environmental quality. Future Water refers to the improvements that have been made to reduce polluting activities but reaffirms the work still to be done.

AECOM County Durham Outline Water Cycle Study 71 Capabilities on project: Water Environment

Appendix B: Relevant Programme of Measures from the Northumberland RBMP

Table B1: Relevant Programme of Measures Sector Pressure Description of the action / What will happen Nutrients, Organic pollution, Sediments, Priority Hazardous Check that your household appliances connect to the foul sewer, not the surface water drain. Substances, Priority Substances and Specific Pollutants Organic pollution, Sediments, Priority Hazardous Substances, Priority Ensure your septic tank or private sewage treatment plant is well maintained and working effectively. Substances and Specific Pollutants Nutrients, Organic pollution, Sediments, Priority Hazardous Use kitchen, bathroom and car cleaning products that don't harm the environment, such as phosphate-free laundry

Substances, Priority Substances and detergents, and use as little as possible. This helps prevent pollution at source. Specific Pollutants Nutrients, Organic pollution, Sediments, Priority Hazardous When you see pollution or fly-tipping, phone us on 0800 807060. Substances, Priority Substances and Specific Pollutants Nutrients, Organic pollution, Sediments, Priority Hazardous Substances, Priority Substances and Adopt-a-river to spot pollution, invasive non-native species, and take part in practical tasks. Specific Pollutants, Direct biological

ACTIONS WE ALL TAKE ALL WE ACTIONS pressures Priority Hazardous Substances, Priority Substances and Specific Ensure your household oil storage is in good condition, with an up-to-date inspection record. Pollutants Priority Hazardous Substances, Take waste oil and chemicals such as white spirit to your municipal recycling facility: don't pour them down the sink Priority Substances and Specific or outside drains. Pollutants Ensure extensions or conservatories have their roof water draining into a soakaway or sustainable drainage system Save water: in your house or office and are not connected to the combined sewer. Save water: in your house or office Ensure that any off-road parking or patio around the house use permeable materials so rain can soak into the soil.

Microbiology; Nutrients; Organic pollutants; Priority Hazardous Make use of the Town and Country Planning Act authorisation process to help minimise risk of diffuse pollution from Substances, Priority Substances and new developments (e.g. implement sustainable drainage systems (SUDS) and use of Water Resource Act Planning

ALL ALL Specific Pollutants; Sediments (as a Guidance) direct pollutant) SECTORS

AECOM County Durham Outline Water Cycle Study 72 Capabilities on project: Water Environment

Sector Pressure Description of the action / What will happen Organic pollutants; Acidification; Direct biological pressures; Nutrients; Where appropriate, subject to the Environment Agency carrying out a 12 week public consultation and making an Physical modification; Priority appropriate case to the Secretary of State, designate a limited number of Water Protection Zones (WPZ). These are Hazardous Substances, Priority a regulatory tool to control diffuse pollution in high risk areas where other mechanisms are not working or are Substances and Specific Pollutants; unlikely to work. Initially around 8 candidate locations across England. Potential for designation from 2010 with a Sediments (as a direct pollutant); possibility of further WPZs by 2012 Microbiology Plans, processes and programmes (such as the Environment Agency's Navigation and Recreation strategies) will be aligned to the requirements of hydromorphology to achieve WFD objectives (especially ecological potential). This Physical modification will be two fold i) mitigation measures required to reach good ecological potential to be delivered through such plans will be identified and ii) the prioritisation of environmental improvements will be influenced by the specific requirements to reach WFD objectives. The Environment Agency will develop and share a GIS linked hydromorphological database. This will supply data to help better understand the hydromorphological impacts of modifications to water bodies. It will feed information into Physical modification the approval/assessment processes to ensure new modifications comply with WFD requirements, especially those related to Article 4 (7). Investigation Monitoring and investigation into mitigation measures techniques to establish the effectiveness of these measures Physical modification and improve understanding of hydro-morph-ecological interactions. Outcomes will have a national application.

Priority Hazardous Substances, Priority Substances and Specific Work to increase awareness of the implications of WFD and promote sustainable drainage systems in new and

NT Pollutants; Microbiology; Organic existing developments, re-use of grey and storm water and the value of green infrastructure in urban developments. pollutants; Nutrients CENTRAL CENTRAL GOVERNME

Abstraction and other artificial flow Roll out delivery from the Reservoir Compensation release project to create more naturalised flows and improve pressures ecology. Use this as best practice to apply to a wider geographic area where appropriate. Abstraction and other artificial flow Undertake education campaigns to targeted audiences to raise awareness of sustainable water use, including pressures conservation and re-use. Joint working across the river basin to identify opportunities for ecological enhancement through restoration of a Diffuse sources; Sediments (as a more natural inundation regime in washlands and / or wider river restoration projects resulting in a more natural flow direct pollutant); Physical modification regime and ecological functionality.

The Environment Agency has identified priority obstructions on the Rivers Tyne, Wear, Tees and Wansbeck. The Environment Agency will seek funding and opportunity to improve passage either through provision of fish passes or Habitat Manipulation removal of obstructions. The Environment Agency will take an opportunistic approach to removing other obstructions (restoration/improvement) to fish migration as funds and opportunities permit.

Catchment Flood Management Plans, Shoreline Management Plans and System Asset Management Plans will Habitat Manipulation ENVIRONMENT AGENCY ENVIRONMENT show where flood risk management and coastal erosion management should continue, be increased or decreased. (restoration/improvement) This could include or lead to habitat creation or river restoration. Environment Agency to produce a WFD mitigation measures manual for flood and coastal erosion risk management Physical modification and land drainage activities. This manual will set out best practice options for measures to mitigate against the impacts of such activities upon ecology. This will be used to ensure that new and existing schemes and

AECOM County Durham Outline Water Cycle Study 73 Capabilities on project: Water Environment

Sector Pressure Description of the action / What will happen management activities will take into consideration WFD requirements and will results in minimal ecological damage. Initiatives to promote community involvement in environment will educate and raise profile of ecological status and importance of river basin’s rivers. For example, the Living Waterways project is supporting better management of Physical modification urban watercourses through working with the community to create habitats and support initiatives for UK BAP species. Flood/Coastal Erosion Risk Management Measure - Sediment management strategies (develop and Physical modification revise) which could include a) substrate reinstatement, b) sediment traps, c) allow natural recovery minimising maintenance, d) riffle construction, e) reduce all bar necessary management in flood risk areas Flood/Coastal Erosion Risk Management Measure - Appropriate water level management strategies, including Physical modification timing and volume of water moved Flood/Coastal Erosion Risk Management Measure - Flow manipulation (e.g. construct structures to normalise flow; Physical modification realign frontage) Physical modification Flood/Coastal Erosion Risk Management Measure - Set-back embankments (a type of managed retreat) Physical modification Flood/Coastal Erosion Risk Management Measure - Undertake bank rehabilitation / reprofiling work Physical modification Flood/Coastal Erosion Risk Management Measure - Managed realignment of flood defence Physical modification Flood/Coastal Erosion Risk Management Measure - Improve floodplain connectivity Priority Hazardous Substances, Provide advice to small and medium sized businesses on obligations in relation to priority substances, priority Priority Substances and Specific hazardous substances and specific pollutants through NetRegs website Pollutants Priority Hazardous Substances, Priority Substances and Specific Enforce REACH Annex 17 restrictions Pollutants Priority Hazardous Substances, Priority Substances and Specific Work to increase awareness of the implications of WFD and promote sustainable drainage systems in new and Pollutants; Microbiology; Organic existing developments, re-use of grey and storm water and the value of green infrastructure in urban developments. pollutants; Nutrients Natura 2000 Protected Areas and SSSI Contribute to maintenance of, or restoration to, favourable conservation status on Natura 2000 Protected Areas Physical modification; Nutrients through Investigation into hydrology and water quality pressures (See Annex D)

Contribute to maintenance of, or restoration to, favourable conservation status on Natura 2000 Protected Areas by Sediments (as a direct pollutant); revoking or amending Discharge/PPC Consents (See Annex D) Nutrients;

Hazardous substances and non- hazardous pollutants; Nitrate; Priority Continue to provide development planning advice on minimising the risk of development to the water environment. Substances and Specific Pollutants Hazardous substances and non- Implement DCLG Planning Policy Guidance Statement 23 (PPS23) on controlling pollution of groundwater, including hazardous pollutants; Priority that which may arise from development of land Substances and Specific Pollutants Hazardous substances and non- Development planning: land contamination - site specific advice and required action for remediation of contaminated hazardous pollutants; Priority

INDUSTRY, INDUSTRY, land through planning liaison Substances and Specific Pollutants

OTHER BUSINESS OTHER Hazardous substances and non- Follow the Sustainable Drainage Systems (SUDS) Interim Code of Practice - comply with published advice for

MANUFACTURING, AND AND MANUFACTURING, hazardous pollutants; Priority operators Substances and Specific Pollutants

AECOM County Durham Outline Water Cycle Study 74 Capabilities on project: Water Environment

Sector Pressure Description of the action / What will happen Hazardous substances and non- hazardous pollutants; Priority Environmental Permitting – regulate effluent discharges to ground Substances and Specific Pollutants Hazardous substances and non- hazardous pollutants; Priority Implement Groundwater Protection: Policy & Practice - External education on groundwater pollution prevention Substances and Specific Pollutants Nitrate; Hazardous substances and non-hazardous pollutants; Priority Re-engineer existing discharges to avoid direct discharges of pollutants to groundwater Substances and Specific Pollutants Local and Regional Government Abstraction and other artificial flow Promote water efficiency in new development through regional strategies and local development frameworks. A pressures Water Cycle Study may be used to identify policy advice on water efficiency measures. Abstraction and other artificial flow Undertake education campaigns to targeted audiences to raise awareness of sustainable water use, including pressures conservation and re-use. Joint working across the river basin to identify opportunities for ecological enhancement through restoration of a Diffuse sources; Sediments (as a more natural inundation regime in washlands and / or wider river restoration projects resulting in a more natural flow direct pollutant); Physical modification regime and ecological functionality. Education and awareness raising with home owners, SME's and Traders regarding wrong drainage connections (when toilets, washing machines, dishwashers, baths etc are connected by mistake to the surface water drain Organic pollutants; Nutrients instead of the foul sewer). For example the weekly Go Green newspaper supplement, aimed at the general public, which has featured issued such as cross connections. Organic pollutants; Nutrients Improved or more targeted street and drain cleaning and maintenance of storm water systems. Environment Agency to produce a WFD mitigation measures manual for flood and coastal erosion risk management and land drainage activities. This manual will set out best practice options for measures to mitigate against the Physical modification impacts of such activities upon ecology. This will be used to ensure that new and existing schemes and management activities will take into consideration WFD requirements and will results in minimal ecological damage. Priority Hazardous Substances, Priority Substances and Specific Work to increase awareness of the implications of WFD and promote sustainable drainage systems in new and Pollutants; Microbiology; Organic existing developments, re-use of grey and storm water and the value of green infrastructure in urban developments. pollutants; Nutrients

Hazardous substances and non- Follow Sustainable Drainage Systems (SUDS) Code of Practice - comply with published advice for operators on hazardous pollutants; Priority

sustainable drainage systems Substances and Specific Pollutants Hazardous substances and non- hazardous pollutants; Priority Highways Agency Programme to investigate soakaways Substances and Specific Pollutants Organic pollutants; Nutrients Improved or more targeted street and drain cleaning and maintenance of storm water systems. Environment Agency to produce a WFD mitigation measures manual for flood and coastal erosion risk management and land drainage activities. This manual will set out best practice options for measures to mitigate against the Physical modification impacts of such activities upon ecology. This will be used to ensure that new and existing schemes and management activities will take into consideration WFD requirements and will results in minimal ecological damage.

URBAN & TRANSPORT URBAN Hazardous substances and non- hazardous pollutants; Priority Follow Pesticides Code of Practice - advice for operators on control of plant protection products Substances and Specific Pollutants

AECOM County Durham Outline Water Cycle Study 75 Capabilities on project: Water Environment

Sector Pressure Description of the action / What will happen Hazardous substances and non- hazardous pollutants; Priority Comply with new EC Sustainable Use of Pesticides Directive to control use of plant protection products Substances and Specific Pollutants Investigations Investigations into the ecological outcomes of measures to mitigate against effects of FCERM activities, improving the understanding of the cost/benefit and technical feasibility of such measures and developing understanding of the Physical modification underlying processes, ecological responses and applicability. Will use case studies, but outcomes will have a national application. Joint working across the river basin to identify opportunities for ecological enhancement through restoration of a Diffuse sources; Sediments (as a more natural inundation regime in washlands and / or wider river restoration projects resulting in a more natural flow direct pollutant); Physical modification regime and ecological functionality. Hazardous substances and non- hazardous pollutants; Nitrate; Priority Comply with discharge consent conditions Substances and Specific Pollutants Nitrate; Hazardous substances and non-hazardous pollutants; Priority Re-engineer existing discharges to avoid direct discharges of pollutants to groundwater Substances and Specific Pollutants

Work in Partnership to deliver habitat improvements through land management solutions. For example, the Belford Nutrients; Sediments (as a direct Catchment Solutions project aims to reduce flood risk and address diffuse agricultural pollution issues and the pollutant); Organic pollutants impact on Budle Bay SPA and SAC, also creating habitats and enhancing biodiversity. Education and awareness raising with home owners, SME's and Traders regarding wrong drainage connections (when toilets, washing machines, dishwashers, baths etc are connected by mistake to the surface water drain Organic pollutants; Nutrients instead of the foul sewer). For example the weekly Go Green newspaper supplement, aimed at the general public, which has featured issued such as cross connections. Organic pollutants; Nutrients Improved or more targeted street and drain cleaning and maintenance of storm water systems. WATER INDUSTRY WATER No deterioration of continuous sewage discharges. Belford Burn from Source to Ross Low; Clow Beck from Source to Ammonia BOD Aldbrough Beck; Embleton Burn form Source to N Sea; Hedleyhope Burn from Source to Deerness; Hummer Beck from Source to Gaunless; South Low from Source to N Sea; Wear from Swinhope to Browney; Wreigh Burn from Foxton Burn to Black Burn; Lumley Park Burn. Ammonia BOD No deterioration of continuous sewage discharges. Twizell Burn from Source to Cong Burn Investigation Investigate emissions from Sewage Treatment Works (STW) and appraise options (to reduce at source or treat at Priority Hazardous Substances, STW) to meet EQS and reduce/cease emissions in this or subsequent rounds (Browney from Source to Pan Burn; Priority Substances and Specific Cong Burn from Source to Twizell Burn; Croxdale Beck from Source to Wear; Lumley Park Burn from Source to Pollutants Herrington Burn; Old Durham Beck from Chapman Beck to Wear; Pont Burn Catchment (trib of Derwent))

AECOM County Durham Outline Water Cycle Study 76 Capabilities on project: Water Environment

Appendix C: SHLAA Sites Potentially at Risk of Surface Water

Ref erence Location Time Frame Settlement 1/AP/04 Land at DDC Depot 6 to 10 years Anfield Plain 1/AP/07 Kyo Road 6 to 10 years Anfield Plain 1/AP/10 East of Stanhope Gardens 11 to 15 years Anfield Plain 1/AP/15 Clavering Place 11 to 15 years Anfield Plain 1/AP/24 Princess Street next 5 years Anfield Plain 1/AP/25 Depot at Derwent Terrace 6 to 10 years Anfield Plain 1/AP/26a Greencroft School 6 to 10 years Anfield Plain 1/BR/06 Rear of South View 11 to 15 years Burnhope 1/BR/08 Greenwood Avenue 6 to 10 years Burnhope 1/BR/10 Whitehouse Farm2 next 5 years Burnhope 1/BU/03 Syke Road 6 to 10 years Burnopfield 1/CO/02 Lamplas 6 to 10 years Consett - Leadgate 1/CO/03b Pont Farm 6 to 10 years Consett - Leadgate 1/CO/05 North of Derwent Crescent 6 to 10 years Consett - Leadgate 1/CO/08 English Martyrs 6 to 10 years Consett - Leadgate 1/CO/09 Villa Real Railway Bridge next 5 years Consett - Leadgate 1/CO/11 Consett Swimming Baths 6 to 10 years Consett 1/CO/15 Shotley Bridge Hospital 6 to 10 years Consett - Shotley Bridge 1/CO/16 Rosedale Avenue next 5 years Consett - Shotley Bridge 1/CO/21 Chaytor Road next 5 years Consett 1/CO/24 Former Pimpernel Factory next 5 years Consett 1/CO/26 Pemberton Road 11 to 15 years Consett 1/CO/28 Mortimer Street 16 years plus Consett 1/CO/31 Berry Edge Business Park next 5 years Consett 1/CO/38 Iveston Road 16 years plus Consett 1/CO/39 McVickers Compound next 5 years Consett 1/CO/42 Templetown Phase 3 6 to 10 years Consett 1/CO/44 South Knitsley Lane 16 years plus Consett 1/CO/52 Dunelm Road 16 years plus Consett - Castleside 1/CO/64 Castleside Resevoir 6 to 10 years Consett - Castleside 1/CO/68 CONSETT 1/CO/69 Generation House next 5 years Consett 1/CO/71 FELL VIEW (NE) next 5 years Consett 1/CO/72 Wood Street next 5 years Consett - Shotley Bridge 1/CO/73 Castle Beck next 5 years Consett 1/CO/75 Queen's Gate (Former Derwentside next 5 years Consett

AECOM County Durham Outline Water Cycle Study 77 Capabilities on project: Water Environment

Ref erence Location Time Frame Settlement College) 1/CO/76 Crookhall Road next 5 years Consett 1/CO/77 St Ives Road 5-28 (NW) next 5 years Consett - Leadgate 1/CO/78 The Chequers next 5 years Consett 1/CO/79 DORSET CRESCENT next 5 years Consett 1/CO/88a Land at Moorside Comprehensive School next 5 years Consett - Castleside 1/CO/89a Consett Community Sports College Site A next 5 years Consett 1/CO/89d Blackfyne Community Sports College Site next 5 years Consett - Shotley Bridge 1/CO/90 CONSETT 1/CO/91 CONSETT 1/CR/04 Oswald Street 16 years plus Craghead 1/DI/08 Lily Gardens next 5 years Flint Hill 1/DI/09 EWEHURST ROAD next 5 years Flint Hill 1/EW/02 Newhouse Road next 5 years Esh Winning 1/HA/03 NICHOLSONS SEALS LTD next 5 years Hamsterley 1/LA/06A LANCHESTER 1/LA/07 Cadger Bank 6 to 10 years Lanchester 1/LP/07 Woodside Farm next 5 years Langley Park 1/ST/03 STANLEY 1/ST/25 Cookson Place 16 years plus Stanley 1/ST/30 Thames Crescent 6 to 10 years Stanley 1/ST/31 Middles Farm next 5 years Stanley 1/ST/34 South Moor Hospital 6 to 10 years Stanley 1/ST/45 LIME STREET (LAND S OF) next 5 years Stanley 1/ST/47 Murray Park next 5 years Stanley 1/ST/49 Station Fields next 5 years Stanley 1/ST/53 Stanley School of Technology next 5 years Stanley 1/TL/03 TANFIELD 1/TM/02 DENEWOOD COURT next 5 years The Middles 2/BO/01 Former Bournmoor Community Centre 6 to 10 years Bournmoor 2/BO/03 Land to the West of Castlefields 16 years plus Bournmoor 2/BO/10 Whitehall Farm 16 years plus Bournmoor 2/CH/01 Blind Lane, Pelaw House next 5 years Chester-le-Street 2/CH/02 Land off Station Road - Chester le Street 11 to 15 years Chester-le-Street 2/CH/12 Police Station_Law Courts 11 to 15 years Chester-le-Street 2/CH/17 Civic Centre 6 to 10 years Chester-le-Street

AECOM County Durham Outline Water Cycle Study 78 Capabilities on project: Water Environment

Ref erence Location Time Frame Settlement 2/CH/18 BOC Site, Birtley 6 to 10 years Chester-le-Street 2/CH/23 Hermitage Comprehensive 6 to 10 years Chester-le-Street 2/CH/25 Chester le Street Bus Depot 11 to 15 years Chester-le-Street 2/CH/34 Ambleside Court next 5 years Chester-le-Street 2/CH/38 Land North of Conyers Avenue 16 years plus Chester-le-Street 2/FE/02 Land north of Morton House 11 to 15 years Fencehouses 2/NF/01 Land adjacent to Pelton Roseberry Comp. next 5 years Newfield School 2/OU/01 Brooms Public House next 5 years Ouston Urpeth 2/PE/06 Land to rear of Elm Ave 11 to 15 years Pelton 2/PF/07 Land East of Bellway development 11 to 15 years Pelton Fell 2/PF/09 Whitehall Farm 6 to 10 years Pelton Fell 2/PF/10 Pelton Fell Regeneration Site (Poets next 5 years Pelton Fell Estate) 2/RI/01 Land at Picktree Lane 16 years plus Rickleton 2/SA/11 Land at Davison Terrace 11 to 15 years Sacriston 2/SA/12 Lingley House Farm North 6 to 10 years Sacriston 2/SA/13b SACRISTON 2/SA/17b SACRISTON 2/SA/21 Lingey House Farm / St Cuthberts Meadow next 5 years Sacriston 2/SA/22 Land at Holly Crescent next 5 years Sacriston 3/BA/02 Aintree Drive next 5 years Bishop Auckland 3/BA/04 Former B B H Windings LTD, 11 to 15 years Bishop Auckland 3/BA/07 St Andrews Estate next 5 years Bishop Auckland 3/BA/08 Land adjacent to Morland Street - Peacock next 5 years Bishop Auckland Court 3/BA/09 Fire Station 11 to 15 years Bishop Auckland 3/BA/11 Cheesmond Avenue 6 to 10 years Bishop Auckland 3/BA/12 Woodhouse Close Estate 6 to 10 years Bishop Auckland 3/BA/18 Tinsdale Hospital - Snowden Cresecent 6 to 10 years Bishop Auckland 3/BA/20 Catkin Ways next 5 years Bishop Auckland 3/BA/21 Former Chamberlain Phipps 6 to 10 years Bishop Auckland 3/BA/24 Holdsforth Farm next 5 years Bishop Auckland 3/BA/29 Bus Depot 6 to 10 years Bishop Auckland 3/BA/38 Land North of Woodhouse Farm 11 to 15 years Bishop Auckland 3/BA/40 Land Opposite St Andrew's Terrace 11 to 15 years Bishop Auckland 3/BA/41 Brack's Farm 16 years plus Bishop Auckland

AECOM County Durham Outline Water Cycle Study 79 Capabilities on project: Water Environment

Ref erence Location Time Frame Settlement 3/BA/43 Land South of Croft Side 11 to 15 years Bishop Auckland 3/BR/05 CROOK 3/CO/02 Land to South of Hillside Road 11 to 15 years Coundon 3/CO/05 Land South of Hillside Road 11 to 15 years Coundon 3/CO/06 Land west of Hillside Road next 5 years Coundon 3/CR/02 Land Rear of High West 11 to 15 years Crook 3/CR/03 Land adjacent to Thistlefalt farm next 5 years Crook 3/CR/06 Land on North East side of Milton Street 11 to 15 years Crook 3/CR/08 Land between Park Avenue and St. Mary's Not achievable Crook Avenue 3/CR/13 Land opposite Glenholme Drive 11 to 15 years Crook 3/CR/15 West End Villas 6 to 10 years Crook 3/CR/25 Wolf Commercial Centre 11 to 15 years Crook 3/CR/37 Land at the Former Crook Works 6 to 10 years Crook 3/CR/40 Land at Greenside Place next 5 years Crook 3/CR/41 7 - 31 park Avenue Close 6 to 10 years Crook 3/DV/03 Auckland Park 6 to 10 years Bishop Auckland - Dene Valley 3/DV/04 Land to the east of St Phillips Close 11 to 15 years Bishop Auckland - Dene Valley 3/HW/05 Land south of Park Avenue 6 to 10 years Howden-le-Wear 3/HW/08 Land adjacent to Railway Street 6 to 10 years Howden-le-Wear 3/RD/30 Eastgate Quarry 6 to 10 years Eastgate 3/SC/01 Land at Rosemount Allotments 16 years plus Bishop Auckland - South Church 3/SC/03 West Deanery Farm next 5 years Bishop Auckland - South Church 3/SH/05 Former Cash and Carry site off Manor next 5 years Bishop Auckland - St Helen Road Auckland 3/SH/07 Land to the north of Middlewood Avenue next 5 years Bishop Auckland - St Helen Auckland 3/SH/09c BISHOP AUCKLAND 3/SH/10 Fountains Square, St. Helens 16 years plus Bishop Auckland - St Helen Auckland 3/SH/13 Land north of Station Road next 5 years Bishop Auckland - West Auckland 3/SH/14 BISHOP AUCKLAND 3/SJ/03 Land rear of Hood Street next 5 years St John's Chapel 3/TL/04 Tow Law Auction Mart next 5 years Tow Law 3/WA/01 Land adjacent to Oakley Farm next 5 years Bishop Auckland - West Auckland 3/WA/03 Land south of Oakley Gross Beck 11 to 15 years Bishop Auckland - West Auckland 3/WA/04b South and West of West Auckland Football 6 to 10 years Bishop Auckland - West Auckland Ground 3/WA/09 Former Bus Depot at West Auckland next 5 years Bishop Auckland - West Auckland

AECOM County Durham Outline Water Cycle Study 80 Capabilities on project: Water Environment

Ref erence Location Time Frame Settlement 3/WI/04 Riding Hall Carpets Limited next 5 years Willington 3/WI/06 Land surrounding Dellside House 11 to 15 years Willington 3/WI/08 31-53 Bourne Way 6 to 10 years Willington 3/WI/15 Land at Dene Estate next 5 years Willington 3/WO/04 St Annes Convent High School next 5 years Wolsingham 3/WO/14 Wolsingham Steelworks next 5 years Wolsingham 4/BE/01 Land North of Cook Avenue, Bearpark 6 to 10 years Bearpark 4/BE/04 Bearpark Colliery Reclamation Site next 5 years Bearpark 4/BO/05 Land at Tail Upon End Lane next 5 years Bowburn 4/BO/06 Former Cape Asbestos Site next 5 years Bowburn 4/HS/11 HIGH SHINCLIFFE 4/BO/14 Land at Prince Charles Avenue and Horton next 5 years Bowburn Crescent 4/BS/02 DURHAM 4/BS/04 DURHAM 4/BS/05 DURHAM 4/CO/03 Land at Coxhoe Industrial Estate next 5 years Coxhoe 4/CO/06 Land at Bogma Hall Farm 6 to 10 years Coxhoe 4/CO/07 Land at Fairview and Coxhoe Pottery 6 to 10 years Coxhoe 4/CO/12 Land adjacent to Lowfield Bugalow 11 to 15 years Coxhoe 4/CO/22 Land to the West of Grange Farm 11 to 15 years Coxhoe 4/DU/03 Former Infant & Nursery School next 5 years Durham City - Gilesgate Moor 4/DU/101 DURHAM 4/DU/102 DURHAM 4/DU/104 DURHAM 4/DU/110 DURHAM 4/DU/112 DURHAM 4/DU/118 DURHAM 4/DU/23 County Hospital, Durham 11 to 15 years Durham City 4/DU/26 Elvet Waterside next 5 years Durham City 4/DU/36 County Durham Fire and Rescue HQ , 6 to 10 years Durham City Finchale Road, 4/DU/46 Sheraton House off Darlington Road next 5 years Durham City - Neville's Cross 4/DU/56 Land at Kepier House 11 to 15 years Durham City 4/DU/61 Land at Sixth Form Centre 11 to 15 years Durham City 4/DU/68 St Leonard's School 11 to 15 years Durham City 4/DU/69 University Hospital, North Durham 16 years plus Durham City

AECOM County Durham Outline Water Cycle Study 81 Capabilities on project: Water Environment

Ref erence Location Time Frame Settlement 4/DU/70 Hollow Drift Site 11 to 15 years Durham City 4/DU/76 DURHAM 4/DU/78 Palatine House 6 to 10 years Durham City 4/DU/79 DURHAM 4/DU/82 Former Service Direct Depot next 5 years Durham City 4/DU/93 Plot 1 - Aykley Heads 6 to 10 years Durham City - Aykley Heads 4/DU/96 Plot 4 - Aykley Heads 6 to 10 years Durham City - Aykley Heads 4/DU/98 Plot 6 - Aykley Heads 6 to 10 years Durham City - Aykley Heads 4/EW/07 Land at Fairview Stables 16 years plus Esh Winning 4/LA/02 Land West of Austin House next 5 years Langley Park 4/LM/03 Land East of Onslow Terrace, Langley 16 years plus Langley Moor Moor 4/LM/04 Land adjacent to Railway Line, 16 years plus Langley Moor 4/LM/11 Langley Hall Farm 6 to 10 years Langley Moor 4/MF/04 Land at Browney Lane, Meadowfield, 6 to 10 years Meadowfield 4/PA/03 Land off Wylam Terrace, Parkhill, 11 to 15 years Parkhill 4/UM/01 Land at Works East of Station Road 11 to 15 years Ushaw Moor 4/WR/04 Land North of Finchale View, West Rainton 6 to 10 years West Rainton (WR003) 5/BL/07 B7: Rear of Belmonte Avenue 16 years plus Blackhall Colliery 5/BL/08 B8: Atlee Avenue_Bevin Grove 16 years plus Blackhall Colliery 5/BL/10 Land at North Blackhall Farm 16 years plus Blackhall Rocks 5/EA/01 E1: Land north of Little Thorpe next 5 years Little Thorpe 5/EA/03 E3: Land South of North Crescent 16 years plus Easington Village 5/EA/04 E4: Glenhurst Farm 6 to 10 years Easington Colliery 5/EA/07b E7: Easington Colliery 6 to 10 years Easington Colliery 5/EA/08 E8: Easington School 6 to 10 years Easington Colliery 5/EA/15 West of Petwell Crescent 11 to 15 years Easington Village 5/EA/16 Holm Hill Gardens, Seaside Lane next 5 years Easington Colliery 5/HA/01 Ha1: Land west of B1280 next 5 years Haswell 5/MU/01 M1: Thomas Brothers Site next 5 years Murton 5/MU/02 M10: Land at Watkin Crescent 6 to 10 years Murton 5/MU/03 M11: Land at Calvert Terrace 6 to 10 years Murton 5/MU/12 M5: Murton Nursery 6 to 10 years Murton 5/MU/17 Land East of Seaview Walk 6 to 10 years Murton 5/PE/01b P1: North Blunts 6 to 10 years Peterlee 5/PE/02 P10: College Site A 6 to 10 years Peterlee

AECOM County Durham Outline Water Cycle Study 82 Capabilities on project: Water Environment

Ref erence Location Time Frame Settlement 5/PE/07 P15: Edenhill next 5 years Peterlee 5/PE/14 P21: ITEC next 5 years Peterlee 5/PE/17 P3: Eden Lane School 11 to 15 years Peterlee 5/PE/18 PETERLEE 5/PE/29 Register Office & East Durham Education 6 to 10 years Peterlee 5/PE/31 Eden Community College 6 to 10 years Peterlee 5/SE/06 S14: Dock Site 6 to 10 years Seaham 5/SE/07 S2: Land west of Council Depot 6 to 10 years Seaham 5/SE/08 S3: Land at School Street 16 years plus Seaham 5/SE/09 S4: Seaham Colliery Site 6 to 10 years Seaham 5/SE/10 S5: Lawnside 6 to 10 years Seaham 5/SE/11 SEAHAM 5/SE/14 S9: Parkside 6 to 10 years Seaham 5/SE/16 Land at Scawpie Dene Not achievable Seaham 5/SE/19 Dawdon Hill Farm next 5 years Seaham 5/SE/20 East Shore Village next 5 years Seaham 5/SE/21 SEAHAM 5/SE/22 SEAHAM 5/SE/23 SEAHAM 5/SH/01 Sh1:Land south of Front St and east of next 5 years Shotton Colliery Windsor Plc 5/SH/02 Sh2: Burns and Moor Terrace next 5 years Shotton Colliery 5/SH/07 Sh7: Former King Street 6 to 10 years Shotton Colliery 5/SO/02 So2:Land at Argyle Place next 5 years South Hetton 5/SO/03 So3: East of Windsor Drive next 5 years South Hetton 5/SO/06 So6: East of Methodist Church 16 years plus South Hetton 5/TH/02 Th2: Land to East of Coopers Close 11 to 15 years Thornley 5/TH/04 Th4:Kenton Crescent next 5 years Thornley 5/DH/01 TRIMDON COLLIERY 5/DH/02 TRIMDON COLLIERY 5/TH/17 THORNLEY 5/WH/05 Wh5: Dog Track 16 years plus Wheatley Hill 5/WI/01 Wi1:Tonks Site next 5 years Wingate 5/WI/17 Land at Low Grange Farm 16 years plus Wingate 6/BC/01 Land at Groves Works 11 to 15 years Barnard Castle 6/BC/12 Thorngate next 5 years Barnard Castle

AECOM County Durham Outline Water Cycle Study 83 Capabilities on project: Water Environment

Ref erence Location Time Frame Settlement 6/CF/08 East of Prospect Terrace 6 to 10 years Cockfield 6/CS/04 Marwood Terrace 6 to 10 years Cotherstone 6/EV/01 Brookside next 5 years Evenwood 6/EV/04 Land at Evenwood next 5 years Evenwood 6/EV/06 Fairfield Lodge 11 to 15 years Evenwood 6/EV/07 Land South of Muirlands 6 to 10 years Evenwood 6/EV/08 EVENWOOD 6/GF/03b GAINFORD 6/GF/03b GAINFORD 6/MT/01 Land at the Bridge Inn 6 to 10 years Middleton-in-Teesdale 6/MT/09 Land South of Pennine Cottage 6 to 10 years Middleton-in-Teesdale 6/SD/01 Land South of High Street 6 to 10 years Staindrop 6/SD/02 Land at Holme Lodge 11 to 15 years Staindrop 6/SD/03 Land South of Sudburn Avenue 6 to 10 years Staindrop 6/SF/01 Land South of Ullathorne Rise 6 to 10 years Barnard Castle - Startforth 6/SF/02 Land West of Startforth Morritt Memorial 6 to 10 years Barnard Castle - Startforth School 6/SF/03 Land South of HM Young Offender 6 to 10 years Barnard Castle - Startforth Instituion 7/AV/081 Congreve Terrace next 5 years Aycliffe Village 7/BG/056 Land North East of High Street 6 to 10 years Byers Green 7/BM/061 North of Stoneybeck 16 years plus Bishop Middleham 7/CH/078a CHILTON 7/CH/016 Land west of Chilton 6 to 10 years Chilton 7/CH/062 CHILTON 7/CH/078/B CHILTON 7/CH/145 Land at Chilton Working Mens Club 6 to 10 years Chilton 7/CH/148 Land west of Keats Road 11 to 15 years Chilton 7/CH/239 Land at 17 Vine Place next 5 years Chilton 7/FB/063 Land Rear of Recreation Ground 6 to 10 years Fishburn 7/FB/145 Land North of Elderberry Farm next 5 years Fishburn 7/FH/018 Bessemer Street 6 to 10 years Ferryhill 7/FH/039 Land south of Dean Road 6 to 10 years Ferryhill 7/FH/087 Land west of Gladstone Terrace 6 to 10 years Ferryhill 7/FH/166 Land East of Croft Gardens (Former 6 to 10 years Ferryhill - Ferryhill Stn NEECOL Site) 7/FH/171 Corner of Barrington Terrace 6 to 10 years Ferryhill

AECOM County Durham Outline Water Cycle Study 84 Capabilities on project: Water Environment

Ref erence Location Time Frame Settlement 7/FH/324 Ashfield Site 6 to 10 years Ferryhill - Ferryhill Stn 7/NA/005 Eldon Whinns 6 to 10 years Newton Aycliffe 7/NA/009 Agnew 5 6 to 10 years Newton Aycliffe 7/NA/079 Elmfield Primary 6 to 10 years Newton Aycliffe 7/NA/090 Land south of Agnew Plantation 6 to 10 years Newton Aycliffe 7/NA/091 Land south of Woodham Way 11 to 15 years Newton Aycliffe 7/NA/130 NEWTON AYCLIFFE 7/NA/185 Windlestone Home Farm next 5 years Newton Aycliffe 7/NA/186 Site N, Cobblers Hall next 5 years Newton Aycliffe 7/NA/187 Site O, Cobblers Hall next 5 years Newton Aycliffe 7/NA/247 Site J, Cobblers Hall next 5 years Newton Aycliffe 7/NA/313 NEWTON AYCLIFFE 7/NA/324 Police Station 11 to 15 years Newton Aycliffe 7/NA/325 Shafto House 6 to 10 years Newton Aycliffe 7/NA/327 Nursing Home 6 to 10 years Newton Aycliffe 7/SF/069 Land south of Eden Drive 16 years plus Sedgefield 7/SF/124 Land at Stockton Road 16 years plus Sedgefield 7/SH/076 Dale Road Industrial Estate next 5 years Shildon 7/SH/201 Shildon on Track next 5 years Shildon 7/SH/312 Land south of West Road 6 to 10 years Shildon 7/SH/313 Land off Burke Street 6 to 10 years Shildon 7/SH/332 Land at Hackworth House, Shildon 6 to 10 years Shildon 7/SP/051 Former Gas Holder Site 11 to 15 years Spennymoor 7/SP/052 Whitworth (Bellway & Yuill) next 5 years Spennymoor 7/SP/052a Whitworth Phase 1 (Barratt) next 5 years Spennymoor 7/SP/052b Whitworth Phase 2 (Barratt / David Wilson next 5 years Spennymoor Homes) 7/SP/073a Land north of Whitworth 11 to 15 years Spennymoor 7/SP/073b Land north of Whitworth Park 11 to 15 years Spennymoor 7/SP/075 Land to the West of Vyners Close 11 to 15 years Spennymoor 7/SP/097 Land north west of Tudhoe Grange School 6 to 10 years Spennymoor 7/SP/139 Land at Merrington Lane 16 years plus Spennymoor 7/SP/152 Black & Decker (Durham Gate) next 5 years Spennymoor 7/SP/153 Electrolux 11 to 15 years Spennymoor 7/SP/155 Merrington Lane Industrial Estate 11 to 15 years Spennymoor 7/SP/216 Land at Grayson Road (George Wimpey) next 5 years Spennymoor

AECOM County Durham Outline Water Cycle Study 85 Capabilities on project: Water Environment

Ref erence Location Time Frame Settlement 7/SP/223 Thorns Lighting 6 to 10 years Spennymoor 7/SP/293 Land at Watson Court (Persimmon Homes) next 5 years Spennymoor 7/SP/312 Former Greyhound Stadium 6 to 10 years Spennymoor 7/TC/127 Land east of St Paul's Road 16 years plus Trimdon Colliery 7/WC/234 Thrislington Depot 6 to 10 years West Cornforth 7/WC/235 Land east of Barratt Way next 5 years West Cornforth

AECOM County Durham Outline Water Cycle Study 86

Capabilities on project: Water

Appendix D: SUDS Potential from SFRA Level 1 (Golder Associates, 2010)

Table D1: SUDS Potential from SFRA Level 1 (Golder Associates, 2010) Area Superficial Geology Solid Geology Topography Possible SUDS

Infiltration devices unlikely to function Hamsterley, Ebchester, Till within river valley (low Falls relatively steeply Limestone & Coal Measures efficiently. Basin/ponds need to take into Burnopfield, Tanfield LEA permeability) north account topography.

Glacial Till. Soils on higher ground low Falls relatively steeply Infiltration systems should operate in low from west to east; lying areas, taking into account local Urpeth, Pelton,Ouston permeability drift deposits. Limestone (variable permeability) In the river valleys soils are relatively flat along River topography; ponds/basins more suitable thicker with relatively high Wear corridor. on higher ground (Stanley) permeability

Infiltration techniques are unlikely to Peat on higher ground – function effectively. High groundwater Cowshill permeable but often Limestone (variable permeability) Elevated levels and buoyancy of structures key supersaturated issues for ponds/basins in peaty soils.

Infiltration techniques are unlikely to Peat on higher ground – Edmondbyers, Hunstanworth, function effectively. High groundwater permeable but often Limestone (variable permeability) Elevated Rookhope, Lintzgarth levels and buoyancy of structures key supersaturated issues for ponds/basins in peaty soils.

Infiltration devices unlikely to function Consett, Lanchester and Glacial till in river valley – Falls relatively steeply Coal Measures of variable permeability efficiently. Basin/ponds need to take into Annfield Plain low permeability west to east account topography.

Glacial till - Low Infiltration potential around low lying Langley Park, Witton Gilbert, permeability on high Falls relatively steeply areas (Chester-le-Street and Durham). Sacriston, Esh Winning, ground, relatively high Limestone (variable permeability) west to east. Flat along They will be less effective in elevated Bournemoor permeability in low lying Wear corridor. areas further west. areas

Easington Colliery, Pittington, Low-intermediate Falls relatively undulating Infiltration and detention systems may Murton, Haswell, South Hetton, permeability Limestone (variable permeability) east to west from higher function subject to local conditions and Ludworth ground SUDS requirements

AECOM County Durham Outline Water Cycle Study 87

Capabilities on project: Water

Area Superficial Geology Solid Geology Topography Possible SUDS

Elevated. Land falls Infiltration unlikely to function effectively. Peat on high ground with rapidly into the valley of High water table and buoyancy of Ireshope Moor Glacial Till in valleys Limestone (variable permeability) the Wear and tees structures possible issues for respectively ponds/basins

Elevated. Land falls Infiltration unlikely to function effectively. Peat on high ground with rapidly into the valley of High water table and buoyancy of Westhope Moor / Stanhope Glacial Till in valley of the Limestone (variable permeability) the Wear and tees structures possible issues for Wear respectively ponds/basins

Drift on higher ground with Falls relatively steeply Wolsingham and Tow Law / Infiltration SUDS unlikely to function Glacial Till in valley bottom. west to east toward River Hamsterley and Witton-le-Wear Limestone (variable permeability) effectively Both low permeability Wear

Glacial drift on higher Infiltration SUDS likely to function Crook and Howden-le-Wear / ground (low permeability) Falls relatively steeply to effectively in low lying areas. Less likely Willington / Witton Park / with thicker till deposits in Wear; flat along Wear Limestone (variable permeability) to function in elevated areas including Spennymoor / Brandon lower areas with relatively corridor around Stanley Crook and Counden. high permeability

Peterlee / Coxhoe, trimdon, Relatively undulating Infiltration and detention systems may Low to intermediate Trindon Colliery, Bowburn, and falling west from higher function subject to local conditions and permeability Limestone (variable permeability) Wingate ground SUDS requirements

Relatively undulating Infiltration and detention systems likely to Intermediate to high East Coast falling towards coastal operate effectively subject to local permeability Limestone (variable permeability) fringe conditions and requirements

Infiltration unlikely to function effectively. High water table and buoyancy of Grains o’ th’ Beck Peat Elevated Limestone (variable permeability) structures possible issues for ponds/basins

AECOM County Durham Outline Water Cycle Study 88

Capabilities on project: Water

Area Superficial Geology Solid Geology Topography Possible SUDS

Falls relatively steeply Mickleton, Middleton-in- Drift (till) deposits - low Infiltration SUDS unlikely to function west to east towards Teesdale permeability Limestone (variable permeability) effectively Tee

Falls relatively steeply Drift (till) deposits - low Infiltration SUDS unlikely to function Stainton and Staindrop Limestone and Coal measures (variable west to east towards permeability effectively permeability) Tee

Infiltration and detention systems likely Bishop Auckland / Newton Low to intermediate Limestone (high permeability) Relatively undulating to operate effectively subject to local Aycliffe / Shildon permeability conditions and requirements

Intermediate to high Infiltration and detention systems likely Sedgefield, Bradbury and permeability (some clay Limestone (high permeability) Relatively flat to operate effectively subject to local Mordon lenses) conditions and requirements

Peat on higher ground and Elevated, falls rapidly Infiltration SUDS unlikely to function Bowes and Gilmonby till in lower ground / Limestone (variable permeability) towards tributaries of effectively valleys Tees

Elevated, falls rapidly Low permeability drift Infiltration SUDS unlikely to function Barnard Castle / Ovington Limestone (variable permeability) towards tributaries of the deposits effectively Tees

Undulating, falls Low permeability till relatively steeply west to Infiltration SUDS unlikely to function Gainford and Winston Limestone (variable permeability) deposits east towards the River effectively Tee