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The Meaford Energy

Planning Act 2008

Revision: Date:

PINS Reference Number: Document Reference Number:

Lead Author: Atkins

6.4.9 Volume 4: Environmental Statement Appendix 14.1:

Meaford Energy Centre Level 2 Flood Risk Assessment Meaford Energy Limited

March 2015

Level 2 Flood Risk Assessment

Atkins Meaford Energy Centre 2

Notice This document and its contents have been prepared and are intended solely for Meaford Energy Limited’s information and use in relation to the construction of the Meaford Energy Centre.

Atkins Limited assumes no responsibility to any other party in respect of or arising out of or in connection with this document and/or its contents.

Document history

Job number: 5105324 Document ref: 5105324-MEA-RPT-000127

Revision Purpose description Originated Checked Reviewed Authorised Date

0 DCO submission BD AB SR DM March 2015

Client signoff

Client Meaford Energy Limited

Project Meaford Energy Centre

Document title Level 2 Flood Risk Assessment

Job no. 5105324

Copy no. 1

Document reference

5105324-MEA-RPT-000127



Table of contents Chapter Pages

Glossary 4 1. Executive Summary 19 2. Introduction 20 2.1. Background 20 2.2. Report Scope 20 2.3. Relevant Policy, Legislation and Guidance 21 3. Site and Surrounding 25 3.1. Proposed Scheme 25 3.2. Site Location and Description 25 3.3. Existing Infrastructure 28 3.4. Current Flood Classification 29 3.5. Climate Change 34 4. Level 2 Flood Risk Assessment 35 4.1. Assessment of Flooding 35 4.2. Application of Flood Risk Policy 39 5. Conclusions and Recommendations 40 5.1. Conclusions 40 5.2. Recommendations 40 Appendix A. Correspondence with the Environment Agency 41



Glossary Full Text Acronym Notes Above Ground Installation

AGI Compound where the Gas Connection connects to the Local Transmission System (work numbered 2A in Schedule 1 of the Order).

Above Ordnance Datum

AOD Height of land surface above sea level.

Air Cooled Condenser

- A direct dry cooling system where the steam is condensed and returned condensate to the boiler without water loss. Situated within the Power Station Complex.

Air Quality Limit Value Regulations 2010

- UK regulations to limit the levels of air borne pollutants emitted from industries.

Air Quality Management Area

AQMA An area designated by a local authority as being at risk of not meeting air quality standards.

Air Quality Management Plan

AQMP A plan developed to improve the air quality in the air quality management area.

Air Quality Modelling and Assessment Unit

AQMAU An Environment Agency team that targets air quality related issues.

Air Quality Strategy

AQS The AQS for England, Scotland, Wales and Northern Ireland provides details of national air quality standards and objectives for a number of local air pollutants.

Ancient Woodland - A woodland that has existed continuously since 1600 or before.

Annual Average Daily Traffic

AADT Measurement unit for the total volume of vehicle traffic to indicate how busy the road is.

Application - The DCO application for the Scheme made to the Secretary of State under the Planning Act 2008.

Applications: Prescribed Forms and Procedure Regulations

APFP The Infrastructure Planning Regulations 2009, as amended, which prescribe various matters in connection with the making of an application for development consent under the Planning Act 2008.

Asbestos Containing Material

ACM Any material containing more than 1% asbestos.

Automatic Traffic Count

ATC Means of determining traffic levels in the vicinity.

Automatic Urban and Rural Network

AURN Air quality monitoring site.

Best Available BAT The most effective and advanced stage in the development of activities and their methods of



Full Text Acronym Notes Technique operation which indicates the practical suitability of

particular techniques for providing the basis for emission limit values and other permit conditions designed to prevent and, where that is not practicable, to reduce emissions and the impact on the environment as a whole.

Biodiversity Action Plan

BAP Plan concerned with the protection of identified species and habitats.

British Geological Survey

BGS The UK public body responsible for all aspects of geoscience.

BS 4142 - Method for Rating Industrial Noise Affecting Mixed Residential and Industrial Areas (1997).

BS 8233 - Guidance on sound insulation and noise reduction for buildings (2014).

BS5228 - Code of Practice for Noise and Vibration Control on Construction and Open Sites 2009 (2009).

CAoL Guidance - Department of Communities and Local Government guidance ‘Planning Act 2008: Guidance related to procedures for the compulsory acquisition of land’ (September 2013).

Canal Bridge 101 or Canal Bridge No.101

- The bridge known as Malkin's Bridge traversing the Trent and Mersey Canal at Grid Reference SJ 889 370.

Carbon Dioxide CO2 A primary greenhouse gas emitted through human activities as well as natural sources.

Carbon Monoxide CO One of the combustion products discharged by CCGT power stations.

Chamber of Commerce

CoC A network of businesses to represent business interests.

Civil Aviation Authority

CAA A statutory corporation that oversees and regulates civil aviation in the UK.

Classified Turning Counts

CTC Measurement of vehicle traffic in particular at junctions.

Coal Authority - A non-governmental body that manages coal mining operations and coal reserves throughout the UK.

Construction Industry Research and Information Association

CIRIA -

Code of Construction Practices

CoCP A guidance document that sets out standards and procedures for managing environmental impact of constructing major schemes.

Combined Cycle Gas Turbine

CCGT A form of power station that uses an efficient combination of gas and steam turbines to generate



Full Text Acronym Notes electricity.

Combined Heat and Power

CHP A means of using waste heat generated by power station e.g. through a local heat distribution network.

Commercial and Industrial waste

C&I A type of waste from businesses that does not include construction and demolition waste.

Common Bird Census

CBC A standardised methodology to map breeding bird territories.

Committee on the Medical Effects of Air Pollutants

COMEAP An advisory body that advises the UK government on all matters concerning the health effects of air pollutants.

Conceptual Site Model

CSM A model that identifies the possible pathways by which a contaminant from a particular source can affect a particular receptor.

Conservation Areas

CA An area of special architectural and historic interest designated by the local planning authority.

Construction Stage

- The construction stage of the Scheme begins with enabling works, which will include site set-up and groundworks and will take in the region of 3-6 months. Following this, construction of the Power Station Complex, Gas Connection and Electrical Connection will be undertaken over a period of approximately 18 months, with commissioning taking in the region of six months.

Construction and Demolition Waste

C&D A type of construction waste as identified by the Environment Agency.

Construction Environmental Management Plan

CEMP A plan by the contractor describing how the environmental impacts of construction activities of a project will be minimised and mitigated.

Construction Traffic Management Plan

CTMP A plan by the construction contractor for managing construction traffic that is submitted to the relevant Highway Authority for approval

Construction Travel Plan

CTP A plan by the construction contractor for managing staff travel during the construction stage of a project (e.g. car sharing, public transport) that is submitted to the relevant Highway Authority for approval.

dB(A) - A-weighted decibel – a correction applied to each frequency between 20 Hz and 20 kHz that effectively represents the way the human ear works.

Decibel dB Logarithmic scale for measuring sound levels.

Decommissioning Stage

- After a notional lifetime of 35 years, the plant for the Scheme would be decommissioned and the MEC Site will revert to open bare ground. The Electrical Connection is likely to be dismantled along with the Power Station Complex. The existing gas pipes are likely to be left in-situ in order to avoid the adverse environmental effects associated with their removal,



Full Text Acronym Notes with the gas supply diverted.

Department for Energy and Climate Change

DECC Government department responsible for energy policy.

Department for Environment, Food and Rural Affairs

DEFRA The UK Government department responsible for environmental protection, food production and standards, agriculture, fisheries and rural communities in the UK.

Department for Transport

DfT Government department responsible for transport.

Deposition - The main pathway for removing pollutants from the atmosphere, by settling on land.

Design Manual for Roads and Bridges

DMRB A suite of technical documents produced by the Highways Agency that include guidance for environmental appraisal that are also used for non-highways schemes and as such are commonly used in EIA.

Determinand - A substance or parameter that is determined analytically, e.g. arsenic concentration in soil, pH of water, concentration of a particular gas in air quality modelling.

Development Consent Order

DCO An order made under the Planning Act 2008 granting development consent for a Nationally Significant Infrastructure Project

Electrical Connection

- The integral underground cable circuit connecting the Power Station Complex to the existing Barlaston Substation (numbered work 3 in Schedule 1 to the Order and as shown on the Works Plan).

Electricity Market Reform

EMR UK government's policy to reform the electricity market. The policy aims to deliver a low carbon energy and reliable supplies for the UK, while minimise costs to consumers.

Electric and Magnetic Fields

EMF EMF’s comprise electric and magnetic fields. Electric fields are the result of voltages applied to electrical conductors and equipment. Magnetic fields are produced by the flow of electric current.

Emission - The direct or indirect release of substances, vibrations, heat or noise from individual or diffuse sources into air, water or onto land, e.g. pollution may be discharged into the atmosphere from a stack or vent.

Emission Limit Value

ELV Legal enforcement limit on the physical, chemical or biological characteristics of a point source of emission to water or air.

Energy Efficiency Directive 2012

- The Directive establishes a framework of measures for the promotion of energy efficiency within the European Union.



Full Text Acronym Notes English Heritage EH The executive non-departmental public body that

advises the public and other bodies on the care of the historic environment in England.

English Heritage Archives

EHA A public archive of architectural and archaeological records.

Environment Agency

EA The non-departmental government body responsible for protection and enhancement of the environment in England and Wales.

Environmental Health Officer

EHO A local authority health professional responsible for carrying out measures for protecting public health.

Environmental Impact Assessment

EIA The process of assessing the likely significant environmental impacts of a proposed project as part of gaining planning consent.

Environmental Permit

EP A permit required in accordance with the Environmental Permitting Regulations.

Environmental Permitting Regulations

EPR The Environmental Permitting (England and Wales) Regulations 2010 (SI 2010/675) as amended that regulates practices that have pollution potential through a permitting system.

Environmental Protection Act 1990

EPA The Act that covers, amongst other things, the regulation of contaminated land in the UK.

Environmental Quality Standards

EQS The concentration of a particular pollutant or group of pollutants in water, sediment or biota which should not be exceeded in order to protect human health and the environment.

Environmental Statement

ES The document which reports the process, findings and recommendations of the EIA carried out to assess the environmental impacts of the Scheme informed by the Scoping Opinion.

Environmentally Sensitive Area

ESA A designation for agricultural areas needing special protection by virtue of their landscape, wildlife or historical value.

Flood Defence Consent

FDC A consent required by the Environment Agency, for construction or maintenance work on over, under or near a main river (usually within 8-10 metres).

Flood Risk Assessment

FRA An assessment that determines the risk of flooding to a proposed project.

Full Time Equivalents

FTE The equivalent number of full time jobs provided by a project - e.g. two half-time jobs equates to one FTE.

Gas Connection - The integral gas pipeline connecting the Power Station Complex to the Local Transmission System, including the Above Ground Installation, (numbered works 2A and 2B in Schedule 1 to the Order and as shown on the Works Plans).



Full Text Acronym Notes

Gas Turbine GT A turbine driven by hot combustion gases at high temperature.

Great Crested Newt

GCN A species of newt protected by European Legislation.

Groundwater Source Protection Zone

GSPZ Areas around groundwater abstraction sources that are defined in order to help protect drinking water from contamination.

Guidance for the Environmental Assessment of Road Traffic

GEART The IEMA guidance on the environmental assessment of road traffic.

Guidance on Transport Assessment

GTA Department for Transport guidance dated March 2007 on the preparation of Transport Assessments as archived 22 October 2014 and replaced by NPPG “Transport evidence bases in plan making”

Guidelines for Landscape and Visual Impact Assessment, 3rd Edition

GLVIA Guidance produced by the Landscape Institute and the Institute for Environmental Management and Assessment dated 17 April 2013

Habitat Regulations Assessment

HRA An assessment required under the European Directive 92/43/EEC.

Habitat Suitability Index

HSI A method for assessing the suitability of ponds for their potential to support Great Crested Newts.

Health and Safety Executive

HSE The non-departmental government body responsible for workplace safety in the UK.

Heat Recovery Steam Generator

HRSG A means of recovering heat energy from hot exhaust gases in order to produce steam for driving a turbine.

Heavy Goods Vehicle

HGV A truck that when laden has a total weight of more than 3500 kg.

Highway Authority HA The relevant highway authority responsible for the non-core road network (i.e. roads other than trunk roads and motorways), usually the county council in two-tier authority areas.

Highways Agency HA The executive agency of the Department for Transport responsible for the core road network in England.

Historic Environmental Record

HER The record held by the local planning authority of known archaeological sites, buildings and landscapes of relevance to the historic environment.

Home and Communities Agency

HCA The executive non-departmental public body responsible for housing and regeneration across England. Also the regulator of registered social housing providers.



Full Text Acronym Notes Hover - An otter’s day nest or resting site.

Indices of Multiple Deprivation

IMD An index to measure deprived areas in the wards of English local authorities.

Industrial Emissions Directive

IED EU Directive on industrial emissions that came into force in January 2011.

Infrastructure Planning Commission

IPC The public body that previously examined applications for development consent to build Nationally Significant Infrastructure Projects, abolished through the Localism Act 2011 with the role replaced by PINS.

Institute of Acoustics

IOA Professional body for Acoustics, Noise and Vibration professionals.

Institute of Air Quality Management

IAQM IAQM is a professional body for air quality professionals.

Institute of Environmental Management and Assessment

IEMA IEMA is a professional body for environmental professionals that provides industry guidance on many topics including EIA.

Institute of Gas Engineers and Managers

IGEM IGEM is a chartered professional body, licensed by the Engineering Council.

Integrated Pollution Prevention and Control Directive

IPPC The EU Directive (2008/1/EC) incorporated into UK law by the Environmental Permitting Regulations on prevention and control of industrial emissions. The Directive aims to achieve a high level protection of the environment through measures to prevent or, where that is not practicable, to reduce emissions to air, water and land from activities listed in Annex I of the Directive (e.g. energy industries, production and processing of metals, mineral industry, chemical industry, intensive pig and poultry farming, waste management, some food and drink industries etc.).

ISO 9613-2 - Acoustics- Attenuation of sound during propagation outdoors – Part 2: General method of calculation.

Joint Nature Conservation Committee

JNCC The public body that advises the UK government and devolved administrations on UK-wide and international nature conservation.

Kilovolt kV A measure of electrical potential.

LA10 - A-weighted noise level exceeded for 10% of the measurement period.

LA90 - A-weighted noise level exceeded for 90% of the measurement period.

LAeq - A-weighted equivalent continuous sound level.

LAmax - A-weighted maximum sound pressure level recorded



Full Text Acronym Notes over a given period.

Landscape Character Assessment

LCA An assessment used to understand and articulate the character of a landscape, by identifying what give a locality it’s 'sense of place' and what makes it different from neighbouring areas carried out pursuant to the Landscape Character Assessment Guidance for England and Scotland.

Landscape Character Assessment Guidance for England and Scotland

LCAG Guidance on Landscape Character Assessment issued by The Countryside Agency (now Natural England) and Scottish Natural Heritage dated 2002.

Land Plan - The plan showing the land required for the Scheme which is to be the subject of the power to acquire new rights, to extinguish or suspend existing rights and/or impose restrictive covenants submitted with the Application (Document Reference 2.2).

Large Combustion Plant Directive

LCPD European legislation to reduce acidification, ground level ozone and particles throughout Europe by controlling emissions of sulphur dioxide, nitrogen oxides and from large combustion plants in power stations.

Laydown Areas - The temporary (Work numbered 5A on the Works Plans) and temporary/permanent (Work numbered 5B on the Works Plans) laydown areas required for the Scheme.

The Laydown Area shown on the Works Plan and numbered Work 5A in Schedule 1 to the Order is the southern laydown area located in the southern part of the Order Limits and will be up to 0.6ha in size. It will be used during construction of the Scheme only.

The Laydown Area shown on the Works Plan and numbered Work 5B in Schedule 1 to the Order is the primary laydown area for the Scheme and will be up to 1.8ha in size and located immediately to the north of the Power Station Complex. It will be used during construction of the Scheme and for maintenance activities during operation.

Lead Local Flood Authority

LLFA The authority responsible for developing, maintaining and applying a strategy for local flood risk management in their areas and maintaining a register of flood risk assets.

Light Duty Vehicles

LDV Vehicles with a weight less than 3.5 tonnes (gross weight).



Full Text Acronym Notes Listed Building A building that has been placed on the statutory list of

buildings of Special Architectural or Historic Interest and protected by the Planning (Listed Building and Conservation Areas) Act 1990 (as amended).

Local Development Framework

LDF A spatial planning strategy introduced by the Planning and Compulsory Purchase Act 2004.

Local Enterprise Partnership

LEP A sub-regional body responsible for setting strategic direction and implementation of economic development.

Local Nature Reserve

LNR Statutory designation for places with wildlife or geological features that are of special interest locally.

Local Transmission System

LTS The Local Transmission System which transports gas from National Transmission System off-takes towards and between urban areas. In the area of the Scheme, the LTS is the PL1134 Barlaston to Sandon.

Local Transport Plan

LTP A plan by a local Highway Authority that sets out a strategy for the future of transport in its area. The LTP for the administrative area of the Scheme is the Staffordshire Local Transport Plan 3, adopted by Staffordshire County Council in 2011.

Local Wildlife Site LWS Wildlife rich sites selected for their local nature conservation value.

Made Ground - Man-made deposits artificially placed comprising a wide variety of material e.g. concrete, brick etc - typical of previously developed sites.

Maintenance - Maintenance can comprise inspections, repair, adjustments or alterations, removal, refurbishments, reconstruction, replacements and improvements.

Manual for Streets MfS The guidance produced by the Department for Transport and Department for Communities and Local Government on road layout and balancing the needs of different road users, with a focus on residential roads, dated 29 March 2007.

Meaford Business Park

MBP The business park with extant planning permission (and bearing planning references: 1998/35897/OUT and issued 1 May 2007, 2010/13609/EXT and 2014/21379/EXTO)) for 110,000 sqm of commercial, warehousing and business support activities on the MBP Site within which the majority of the Scheme will be constructed.

MBP Site - The location of Meaford Business Park.

Meaford Energy Centre (also referred to as the "Scheme")

MEC The construction, operation, maintenance and eventual decommissioning of the Power Station Complex, the Gas Connection and the Electrical Connection, the construction and use of the Northern Access Road, the Laydown Areas and landscaping



Full Text Acronym Notes (Work numbered 7 in Schedule 1 to the Order).

MEC Site (also referred to as the "Site")

- The area in which the Scheme will be constructed, operated and decommissioned as defined by the Order Limits.

Meaford Energy Limited

MEL The applicant for the Application and the developer of the Scheme.

Megawatts of electrical power

MWe Measurement of electrical power.

Megawatts of thermal power

MWth Measurement of thermal power.

Milligrams per normal cubic metre

mg/ Nm3 Unit of concentration of emission limit values.

Multi Agency Geographical Information for the Countryside

MAGIC A web-based mapping browser showing various geographical designations e.g. nature conservation sites, heritage sites.

National Character Area

NCA Distinct natural areas of England, defined by a unique combination of landscape, biodiversity, geodiversity and cultural and economic activity.

National Cycle Network

NCN A network of signed and promoted cycle routes across the UK.

National Grid Company

NGC National Grid's principal operations are the ownership and operation of regulated electricity and gas infrastructure networks.

National Monuments Record

NMR Currently known as English Heritage Archive.

National Nature Reserve

NNR Statutory designations, where places with wildlife or geological features that are significant at a national level.

National Planning Policy Framework

NPPF The National planning policy framework for England, dated March 2012

National Planning Practice Guidance

NPPG The Planning Practice Guidance web based resource for England first introduced in March 2014 (and which largely superseded planning policy statements (PPGs)) providing guidance on National planning policy and the operation of the planning system

National Policy Statements

NPS Overarching legislative policy concerning the planning and consenting of NSIPs in the UK.

National Transmission System

NTS The strategic natural gas pipeline serving the UK.

Nationally Significant

NSIP As defined by the Planning Act 2008, which includes within the definition of an NSIP any onshore



Full Text Acronym Notes Infrastructure Project

generating station in England and Wales of 50 Mwe capacity or above.

National Air Traffic Control Services

NATS -

Natural England NE The non-departmental government body responsible for England's natural environment.

Nitrate Vulnerable Zone

NVZ A designated area where land drains into and contributes to nitrate found in nitrate-polluted waters.

Nitrous oxides NOx One of the combustion products discharged by CCGT power stations .

Noise Policy Statement for England

NPSE Policy that sets out the long term vision of government noise policy.

Noise Sensitive Receptor

NSR Receptors principally residential dwellings (existing or for which planning consent is being sought/ has been given) and any building used for long term residential purposes (such as nursing home).

Non-Technical Summary

NTS The non-technical summary of the Environmental Statement.

Northern Access Road

The existing haul road to the MBP Site located off Meaford Road in the borough of Staffordshire being upgraded pursuant to the Order (work numbered 4 in Schedule 1 of the Order).

Okta - A unit used in expressing the extent of cloud cover, equal to one eighth of the sky.

Operation - The routine day to day functioning of the MEC.

Order - The Meaford Energy (Gas Fired Power Station) Order, being the development consent order to be made by the Secretary of State authorising the Scheme, a draft of which is submitted with the Application (Document Reference 3.1)

Order Land - The land shown on the Land Plan which is within the Order Limits

Order Limits - The limits shown on the Works Plans within which the Scheme may be carried out.

Ordnance Survey OS National mapping agency for Great Britain

Otter Faeces Spraint -

Overhead Line OHL Network of overhead electricity transmission lines

Part II A - The section of EPA 1990 that deals with contaminated land.

Annual Average Flow Rate for surface water

QBAR -



Full Text Acronym Notes runoff

Particulate Matter PM Very small solid particles discharged by CCGT power stations.

Pathway - The route by which contamination moves from a source to a given receptor.

Peak Particle Velocity

PPV A term used to measure vibration through a solid surface. When a vibration is measured, the point at which the measurement takes place can be considered to have a particle velocity.

PEIR site boundary

The wider site boundary identified for environmental survey purposes within the Preliminary Environmental Information Report.

Percentage Heavy Goods Vehicles

%HGV Percentage of traffic that is classified as Heavy Goods Vehicles in a 16hr period.

Permitted Development

- Development that is deemed under legislation to have planning consent without the need to obtain planning permission.

Personal Protective Equipment

PPE Equipment a person may wear to protect themselves from risks e.g. high-visibility jackets, gloves, steel toe capped boots.

Pipeline Inspection Gauge

PIG Pipeline cleaning device.

Planning Act 2008 PA 2008 England and Wales legislation which established the legal framework to apply for, examine and determine applications for Nationally Significant Infrastructure Projects.

Planning Inspectorate

PINS Executive agency supported by the Department for Communities and Local Government which deals with planning appeals, national infrastructure, planning applications, examinations of local plans and other planning related and specialist casework in England and Wales.

Pollution Prevention Guidance

PPG Environment Agency published guidance on pollution prevention and best practice.

Polycyclic Aromatic Hydrocarbon

PAH One of the combustion products discharged by CCGT power stations.

Potential Contaminant Linkages

PCL The existence of a contamination source and a receptor where a pathway is also present linking the two.

Power Station Complex

- The building element of the power station, including gas turbine building, Stack(s), HRSG(s), transformers, steam turbine building, admin/control building, heat interface building, pressure regulation installation, water tanks, car parking, internal site roads, workshop, water treatment plant, switchyard, switchgear room



Full Text Acronym Notes and surface and foul water drainage (please refer to Works numbered 1 and 6 in Schedule 1 to the Order).

Preliminary Environmental Information Report

PEIR A report describing the preliminary environmental assessment during the pre-application process of an NSIP.

Public Right of Way

PRoW Paths on which the public have legally protected rights to pass.

Pulverised Fuel Ash

PFA A solid waste product of coal fired power stations.

Rail Bridge 104 - The bridge known Railway Bridge 104 crossing the West Coast Mainline Railway at Grid reference SJ 891 371.

Receptor - An identified aspect of the environment - e.g. a resident, protected species, heritage asset, controlled water etc - that may be affected by the Scheme and, as such, has been assessed as part of the EIA undertaken.

Registered Parks and Gardens

- Gardens and designed landscapes of special architectural and historic importance, placed on a national register by English Heritage.

Remediation - The clean up of contaminated soil to make it suitable and safe for future use.

River Basin Management Plan

RBMP A management tool created by Environment Agency to use for integrated water resources management.

Scheduled Ancient Monument

SAM A "nationally important" archaeological site or historic building, protected under the Ancient Monuments and Archaeological Areas Act 1979.

SCC Highway

Works

- The construction of a new southern access by Staffordshire County Council to the MBP Site together with associated highway improvements including a new A34 Meaford Road roundabout, footpath/cycleway, lighting and landscaping at Meaford Road, Stone, Staffordshire to be carried out pursuant to the planning permission (bearing planning reference S.14/07) dated 16 January 2015.

Scheme (also referred to as the "MEC")

- The construction, operation, maintenance and eventual decommissioning of the Power Station Complex, the Gas Connection and the Electrical Connection, the construction and use of the Northern Access Road, the Laydown Areas and landscaping (Work numbered 7 in Schedule 1 to the Order).

Scoping Opinion - The Scoping Opinion provided by the Secretary of State in April 2014 and included in the Appendices to the Environmental Statement (Document Reference



Full Text Acronym Notes 6.4 (section 5.1)).

Secretary of State SoS The decision maker for a NSIP application and head of the relevant government department. In the context of the Scheme the decision maker is the Secretary of State for Energy and Climate Change.

Severn Trent Water

STW -

Site (also referred to as the "MEC Site")

- The area in which the Scheme will be constructed, operated and decommissioned as defined by the Order Limits.

Site of Nature Conservation Interest

SNCI Non-statutory areas of local importance for nature conservation.

Site of Special Scientific Interest

SSSI A geological or biological conservation designation denoting a protected area in the UK.

Site Waste Management Plan

SWMP The strategic document dealing with the effective management of materials used for the construction and the operation of the Scheme ensuring that waste is considered at all stages of the Scheme. The SWMP will form part of the CEMP for the Scheme.

Sound Power Level

SWL The Sound Energy flow per unit of time.

Sound Pressure Level

SPL Logarithmic measure of the sound pressure of a sound relative to a reference value, the threshold of hearing.

Special Area of Conservation

SAC Area of protected habitats and species as defined in the European Union's Habitat Directive (92/43/EEC).

Special Landscape Areas

SLA Local designation to provide protection for locally significant and attractive landscapes.

Special Protection Area

SPA A designated area for birds under the European Union Directive on the Conservation of Wild Birds (2009/147/EC)

Stack - The structure by which the exhaust gases and waste heat from the Scheme will be emitted to the atmosphere. .

Stafford Borough Council

SBC The borough council and relevant planning authority for the area within which the MEC Site is located.

Staffordshire County Council

SCC The county council and Highway Authority for the area in which the MEC Site is located.

Statement of Community Consultation

SoCC A statement describing how an applicant proposes to consult the local community about a project.

SuDs Approval Body

SAB -



Full Text Acronym Notes Sulphur Oxides SOx One of the combustion products discharged by CCGT

power stations.

Sustainable Urban Drainage Systems

SuDS -

Switchgear - The combination of switches, fuses or circuit breakers used to control, protect and isolate electrical equipment. Can be air-insulated or gas-insulated.

Tonnes per annum tpa Unit for measuring waste produced.

Total Petroleum Hydrocarbons

TPH One of the combustion products discharged by the type of power station proposed by the Scheme.

Transport Analysis Guidance

TAG Guidance from the Department for Transport on how to assess transportation schemes first published on 29 October 2013 and last updated on 10 November 2014.

Tree Preservation Order

TPO A written order made by the local authority which makes it an offence to intentionally damage or remove a tree protected by that order without the authority's permission.

Waste (England & Wales) Regulations 2011

- Legislations for the waste prevent, management and introduction of waste hierarchy. The regulations apply to England and Wales only.

Water Framework Directive

WFD The Water Framework Directive is a European Union directive which commits EU member states to achieve good qualitative and quantitative status of all water bodies by 2015.

Water Resources Act 1991

WRA Legislation to prevent and minimise pollution of water.

Weighted Sound Reduction Index

Rw Single-number quantity which characterises the airborne sound insulation of a material or building element over a range of frequencies when tested in a laboratory.

Wildlife and Countryside Act 1981

Legislation which protects animals, plants and certain habitats in the UK.

World Health Organisation

WHO A United Nations agency concerned with public health.

Works Plans - The plans showing the numbered Works referred to in the Order and submitted with the Application (Document Reference 2.3).

Zone of Theoretical Visibility

ZTV A computer generated plan showing a maximum area of the surroundings within which a project could theoretically be viewed.



1. Executive Summary 1.1.1. This Flood Risk Assessment (FRA) is based on readily available existing information (including

reference to the 2008 Stafford Borough Council Strategic Flood Risk Assessment (SFRA) completed by Halcrow Group Limited), together with publicly available information, to confirm the extent of flood risk within and surrounding the Order Limits of the Meaford Energy Centre (MEC or Scheme).

1.1.2. This FRA includes a review of site specific information and likely extent of flood risk; identification of surface water management issues related to the Scheme that may warrant further consideration; identification, scoping and review of other flood risks as required i.e. groundwater flooding; and determining whether further assessment is required.

1.1.3. This FRA goes on to conclude that the following sources of flood risk will not require further assessment and are unlikely to present a risk to the Order Limits and surrounding area:

• River flooding (fluvial) – works proposed within the Order Limits fall within flood zone 1 (with the exception of the outfall to the River Trent, which is below ground level) and as such are considered to be at low risk from fluvial flooding, and therefore will not require further assessment or the implementation of mitigation measures.

• Coastal/ tidal flood risks – the Order Limits is not near the sea.

• Sewer flooding – the Order Limits contains no active sewer network.

1.1.4. Infrastructure failure – land within the Order Limits is not impacted by the potential flood risk from reservoirs or lakes and therefore is not considered at risk of this source of flooding.



2. Introduction 2.1. Background 2.1.1. Atkins have been instructed by Meaford Energy Limited (MEL), to undertake a Flood Risk

Assessment (FRA) in relation to the development of the Meaford Energy Centre (MEC) (the Scheme) at the Meaford Business Park (MBP), Staffordshire. This FRA has been prepared to support a Development Consent Order (DCO) (the Order) for a Combined Cycle Gas Turbine (CCGT) power station.

2.1.2. MEL is promoting the Scheme on land within Meaford Business Park (the MBP Site) between Barlaston and Stone in Staffordshire. The MBP Site is an area of previously-developed or ‘brownfield’ land occupied formerly by two coal-fired power stations (Meaford 'A' and Meaford 'B'), now demolished. The MBP Site occupies a low-lying position between the River Trent and the Trent and Mersey Canal and the MBP has outline planning permission for warehousing, industrial, offices and business support activities.

2.1.3. Development has the potential to be at risk from a range of flooding mechanisms and, as such increase the potential flood risk to the Scheme and the surrounding area. Therefore, flood risk is assessed with respect to damage to properties, risk to human life, and the effect the Scheme may have on surrounding bodies of water and drainage systems. This Level 2 FRA has been prepared based on the Level 1 FRA1 which identified land within the Order Limits study area of the Scheme as being at risk from flooding which included fluvial flooding, groundwater flooding, overland flooding, flooding from canals and artificial waterways and reservoir / lake flooding.

2.1.4. This FRA has been prepared to examine these possible sources of flooding, within the context of the National Planning Policy Framework (NPPF)2 and National Planning Practice Guidance (NPPG)3.

2.1.5. The study area covered in this FRA includes the land within and surrounding the Order Limits. For the purposes of this assessment the MEC Site is identified as land within the Order Limits.

2.2. Report Scope 2.2.1. This FRA is based on readily available existing information (including reference to the 2008

Stafford Borough Council Strategic Flood Risk Assessment (SFRA) completed by Halcrow Group Limited4), together with publicly available information, to confirm the extent of flood risk within and surrounding the MEC Site. The FRA includes a review of site specific information and likely extent of flood risk; identification of surface water management issues related to the Scheme that may warrant further consideration; identification, scoping and review of other flood risks as required (i.e. groundwater flooding); and determining whether further assessment is required.

2.2.2. An FRA should consider a range of flooding mechanisms to satisfy the following three key objectives:

• to assess flood risk to the Scheme and to demonstrate whether any residual risk to the Scheme and its user would be acceptable;

• to assess the potential impact of the Scheme on flood risk elsewhere and to demonstrate that the Scheme would not increase flood risk elsewhere; and

• to satisfy the requirements of national planning.

2.2.3. Flood risk should be considered alongside other spatial planning matters such as transport, housing, economic growth, natural resources, regeneration, biodiversity, the historic environment and the management of other hazards. Policies should recognise the positive contribution that avoidance and management of flood risk can make to the development of sustainable communities, including improving local amenities and better overall quality of life.

1 Meaford Energy Centre, Level 1 Flood Risk Assessment, Meaford Energy Limited, 31 January 2014 2 Department for Communities and Local Government, 03/2012. National Planning Policy Framework 3 Department for Communities and Local Government, 26/06/2014, Planning Practice Guidance, http://planningguidance.planningportal.gov.uk/blog/guidance/flood-risk-and-coastal-change/ 4 Stafford Borough Council (Halcrow), 01/2008. SFRA for LDF: Level 1. Study area extends to cover Lichfield District Council/Stafford Borough Council/ Staffordshire Moorlands District Council/ Tamworth Borough Council

http://planningguidance.planningportal.gov.uk/blog/guidance/flood-risk-and-coastal-change/



2.2.4. An FRA should be carried out to an appropriate degree at all stages of the planning process. It should assess the risks of all forms of flooding to and from the Scheme, taking into account climate change, and should inform the application of the sequential approach if needed.

2.2.5. CIRIA C624 “Development and Flood Risk – Guidance for the Construction Industry”5 recommend a phased approach with three levels of assessment as defined below:

• Level 1: Screening Study to identify whether there are any flooding or surface water management issues related to a development site that may warrant further consideration. The screening study will ascertain whether a Level 2 or 3 FRA is required;

• Level 2: Scoping Study to be undertaken if the Level 1 FRA indicates that the site may lie within an area that is at risk of flooding, or that the site may increase flood risk due to increase run-off. This study should confirm the sources of flooding which may affect the site; and

• Level 3: Detailed Study to be undertaken if the Level 2 study concludes that the quantitative analysis is required to assess the flood risk related to a development site.

2.2.6. The Level 2 Flood Risk Assessment presented includes:

• assessment of all forms of residual flood risk identified (groundwater flooding, overland flows, Infrastructure failure);

• an assessment of the volume of surface water run-off likely to be generated by the Schemeand proposals for its management;

• the likely impact of any displaced water on third parties caused by alterations to ground levels;

• estimates of how climate change could affect the probability and intensity of flood events with details of how the Scheme remains safe without increasing flood risk for its design life (35 years); and

• consideration of the Scheme relative to any existing Strategic Flood Risk Assessment carried out by the relevant planning authority.

2.3. Relevant Policy, Legislation and Guidance Overview

2.3.1. The Level 2 FRA has been undertaken using the following legislation and guidance:

• National Planning Policy Framework (NPPF);

• National Planning Practice Guidance (NPPG);

• Flood and Water Management Act 2010;

• Stafford Borough Council Strategic Flood Risk Assessment (SFRA);

• Southern Staffordshire Surface Water Management Plan Phase 1 (Royal Haskoning);

• River Trent Catchment Flood Management Plan6.

National Policy

National Planning Policy Framework 2.3.2. The National Planning Policy Framework (NPPF), published in March 2012, is a key part of the

government’s reform to make the planning system less complex and more accessible; to protect the environment and to promote sustainable growth.

2.3.3. In addition, the online resource Planning Practice Guidance: Flood Risk and Coastal Change published in March 2014 by the Department for Communities and Local Government has also been reviewed in relation to flood risk.

5

Construction Industry Research and Information Association (CIRIA), 2004, CIRIA C624: Development and Flood Risk – Guidance for the Construction Industry

6 Environment Agency, 2010. River Trent Catchment Flood Management Plan, Summary Report



2.3.4. The NPPF aims to prevent inappropriate development in areas at risk of flooding and to ensure that where development is necessary in areas at risk of flooding, it is safe, and the risk of flooding is not increased elsewhere. Local authorities should only consider development in flood risk areas appropriate where informed by a site specific FRA, based upon the Environment Agency’s standing advice on flood risk.

2.3.5. The NPPF requires that a site specific flood risk assessment (FRA) is required for proposals of 1 hectare or greater in Flood Zone 1; all proposals for new development (including minor development and change of use) in Flood Zones 2 and 3; in an area within Flood Zone 1 which has critical drainage problems (as notified to the local planning authority by the Environment Agency); and where proposed development or a change of use to a more vulnerable class may be subject to other sources of flooding. The FRA should identify and assess the risks of all forms of flooding to and from a development and demonstrate how flood risks will be managed so that the development remains safe throughout its lifetime, taking climate change into account.

2.3.6. Development should be directed as far as practicable towards Flood Zone 1 areas (low probability (less than 0.1% annual exceedance probability (AEP) of fluvial/ sea flooding)) to avoid fluvial flood risks wherever possible. For developments proposed in Flood Zone 1, if the development area is greater than 1 hectare an FRA will still be required to address design issues related to the control of surface water run-off and climate change, as well as considering any other potential sources of flood risk for the development.

Flood Risk and Flood Probability 2.3.7. The risk framework outlined in the SFRA defines the flood risk using the categories in Table 2.1.

The fluvial extent map defines the geographical extent of Flood Zones 1, 2, 3a and 3b.

Table 2.1: Fluvial Flood Zone Definition

Potential Residual Effects

Further assessments and consultation to be undertaken Potential Residual Effects

Flood Zone 1 At risk from flood event greater than the 1 in 1000 year event (greater than 0.1% annual probability).

Low Probability

Flood Zone 2 At risk from flood event between the 1 in 100 and 1 in 1000 year event (between 0.1% and 1% annual probability).

Medium Probability

Flood Zone 3a

At risk from a flood event less than or equal to the 1 in 100 year event.

High Probability

Flood Zone 3b

Land which would flood with an annual probability of 1 in 20 (5%) or greater in any year or is designed to flood in an extreme (0.1%) flood or otherwise defined by the Local Planning Authority. This zone also comprises land where water has to flow or be stored during periods of flooding.

Functional Floodplain

2.3.8. Flooding is a natural process that can present a range of different risks depending on its form. Flood practitioners and professionals define the risks presented by flooding according to an Annual Exceedance Probability (AEP), or as having a ‘return period’.

2.3.9. Flood risk includes the statistical probability of an event occurring and the scale of the potential consequences. Flood risk is estimated from historical data and expressed in terms of the expected frequency of a flood of a given magnitude. The 10 year, 50 year and 100 year floods have a 10%, 2%, and 1% chance of occurring in any given year, respectively. However, over a longer period the probability of flooding is considerably greater.

2.3.10. For example, for the 100 year return period flood:

• there is a 1% chance of the 100 year flood occurring or being exceeded in any single year;

• a 26% chance of it occurring or being exceeded in a 30 year period; and

• a 51% chance of it occurring or being exceeded in a 70 year period.

2.3.11. Table 2.2 below provides a summary of the relevant AEP and corresponding return period events of a particular severity.




AEP Definition

100% 1 in 1 Year 10% 1 in 10 Years 2% 1 in 50 Years 1% 1 in 100 Years 0.5% 1 in 200 Years 0.1% 1 in 1,000 Years

Vulnerability Classification 2.3.12. The vulnerability of the development of land use must be taken into account as the

consequences of flooding may not be acceptable for particular types of development. The Planning Practice Guidance defines the ‘Flood Risk Vulnerability’classification (Table 2.3) based on the intended use of a proposed development site.


Flood Risk Vulnerability Classification

Essential Infrastructure

Water Compatible

Highly Vulnerable

More Vulnerable

Less Vulnerable

Floo

d Zo

ne

Zone 1

Zone 2 Exception Test Required

Zone 3a Exception Test Required

Exception Test Required

Zone 3b Exception Test Required

Key: Development is appropriate Development is not appropriate

Sequential Test 2.3.13. The NPPF states that the risk-based Sequential Test should be applied at all stages of planning.

Its aim is to steer new development to areas at the lowest probability of flooding. Development should be directed to areas within Flood Zone 1 wherever possible and, if this is not possible, then development should be sequentially directly to areas least at risk within Flood Zone 2 and the Flood Zone 3.

Exception Test 2.3.14. If, following the application of the Sequential Test, it is not possible or consistent with wider

sustainability objectives for the development to be located in zones of lower probability of flooding, the Exception Test can be applied. This test is only appropriate for use when there are large areas in Flood Zones 2 and 3 and the Sequential Test alone cannot deliver acceptable sites, but where some continuing development is necessary for wider sustainable development reasons.

2.3.15. For the exception test to be passed, the NPPF indicates that developments must comply with the following:

• demonstrate that the relevant scheme provides wider sustainability benefits to the community that outweigh the flood risk, informed by a SFRA where one has been prepared; and

• a site specific FRA must demonstrate that the relevant scheme will be safe over its lifetime take account of the vulnerability of its users, without increasing flood risk elsewhere and, where possible, reducing flood risk overall.



Local Policy

Strategic Flood Risk Assessment 2.3.16. A SFRA was produced on behalf of Staffordshire County Council and Stoke-on-Trent City

Council in 20107 by Land Use Consultants and SLR Consulting Ltd. This SFRA was informed by District and Borough Council SFRAs. Of particular relevance to this project is the Stafford Borough Council SFRA completed by Halcrow Group Limited in 2008.

2.3.17. The sequential test as detailed above, which directs developments away from areas of high flood risk, was used in the Staffordshire County Council’s SFRA.

2.3.18. The findings of the Stafford Borough Council 2008 SFRA have been used to inform this FRA.

Surface Water Management Plan (SWMP) 2010 2.3.19. The SWMPError! Bookmark not defined. has been produced by Royal Haskoning on behalf of

Stafford Borough Council (SBC) along with other neighbouring councils within Staffordshire. Whilst this SBC SWMP does not mention Meaford or the MBP Site specifically, the aim of the document is to establish a partnership between the key consultees and stakeholders, collect and collate existing information on surface water flooding; and select an approach to carry out further analysis.

2.3.20. In this context surface water flooding refers to flooding from sewers, drains, groundwater, and 2.3.20. In this context surface water flooding refers to flooding from sewers, drains, groundwater, and run-off from land, small watercourses and ditches that occurs as a result of heavy rainfall.

Environmental Agency

River Trent Catchment Flood Management Plan (CFMP) 2.3.21. The CFMP is a plan produced by the Environment Agency to aid the understanding of the scale

and extent of flooding now and in the future, and enable the setting of policies for managing flood risk within the catchment. The CFMP’s aim is to promote more sustainable approaches to managing flood risk. The CFMP summarises the need to manage future flood risk with four main messages:

• flood defences cannot be built to protect everything;

• climate change will be the major cause of increased flood risk in the future;

• the floodplain is our most important asset in managing flood risk; and

• development and urban regeneration provide a crucial opportunity to manage the risk.

2.3.22. This CFMP6 divides the River Trent catchment into 10 sub-areas, with Meaford (where the MEC Site is located) represented within sub-area 7 West Staffordshire. This includes the areas of Stoke-on-Trent, Stafford and Cannock. The catchment contains varied landscape with a significant rural element and a fast response to rainfall in watercourses due to the steep nature of the upper catchment. Various areas including Stoke-on-Trent, Stone, Stafford and Cannock experience disruption from flooding, the risk of which has been reduced by flood defence works. Flood risk in sub-area 7 West Staffordshire is considered low with 110 properties at risk during a 1% flood event when taking into account flood defences. Flooding is not expected to increase considerably in the future as a result of climate change or urban growth.

7 Staffordshire County Council and Stoke-on-Trent City Council, 07/2010. Staffordshire and Stoke-on-Trent Joint Waste Core Strategy: Strategic Flood Risk Assessment.



3. Site and Surrounding 3.1. Proposed Scheme 3.1.1. The study area for the purposes of this assessment is shown as the Order Limits in Figure 3.1

and includes the following three integral components:

• the Power Station Complex;

• the Electrical Connection; and

• the Gas Connection.

3.1.2. A full description of the Scheme is included in Chapter 4 of the ES main statement (document reference 6.2).

3.2. Site Location and Description 3.2.1. To the east of the MBP Site on which the Scheme is located is the Trent and Mersey Canal

(Canal), which runs continuously along the eastern boundary. East of the Canal is the West Coast Mainline. To the west of the MBP Site is the River Trent. The Order Limits meet the River Trent at the point of the proposed surface water discharge corridor on the west of the MEC Site, as shown on Figure 3.1.

3.2.2. Access to the MEC Site is currently via the existing Northern Access Road (off Meaford Road).

3.2.3. The Gas Connection is the most easterly point of the Order Limits, as illustrated on Figure 3.1. The Gas Connection is approximately 760 m long and will be largely underground, except when crossing the canal over ground,(approximately 140 m) between the Canal Bridge 101 (Malkin’s Bridge) and the West Coast Mainline using the existing rail bridge (Rail Bridge 104), before going underground to connect with the existing National Grid gas local transmission system (LTS). The Gas Connection will include an Above Ground Installation (AGI) that will be constructed to the east of the West Coast Main Line.



Figure 3.1: Illustrative Works Plan showing the MEC Site and Order Limits

3.2.4. The MBP Site is located in a low lying position between the River Trent and the Trent and Mersey Canal. Although the land within the Order Limits is generally on a level gradient the surface is undulating due to excavations and stockpiles of soil and rubble associated with the demolition of the former Meaford 'A' and 'B' power stations.

3.2.5. From current Ordnance Survey (OS) mapping8, the Northern Access Road (the main access into the MBP) to the north of the Order Limits is at approximately 98m Above Ordnance Datum (AOD); the north-eastern part of the Order Limits, adjacent to the Trent and Mersey Canal, has the greatest elevation of approximately 105 m AOD; and overall the MEC Site slopes at a shallow gradient, with the areas at the western extent having an elevation of approximately 95 m AOD.

Hydrology

3.2.6. There are two watercourses adjacent to the Order Limits. The River Trent lies to the west and the Trent and Mersey Canal lies to the east. In addition, an un-named tributary of the River Trent is located approximately 1.3 km to the south of the Order Limits, which flows east to west, towards the River Trent.

3.2.7. Within the Order Limits, several small water bodies have been identified (Figure 3.2). Immediately to the north of the Order Limits, a waterbody within a wooded area is present which is also located adjacent to the existing Northern Access Road of the MBP Site. The waterbody is fed by a surface watercourse or field drain which originates in the fields to the north to the Order Limits. The pool outfalls through an extended culvert (>50 m length) which runs south-west under the Northern Access Road under the area of the existing tennis courts and the Barlaston Bowling Green.

3.2.8. Of the other six ponds/water bodies (as illustrated in Figure 3.2) within the Order Limits, three are located along the eastern boundary and two are located within the southern area and a water-filled ditch is present on the western extent of the Order Limits. It is currently unconfirmed how

8 Ordnance Survey map: http://www.streetmap.co.uk/map (Accessed on 19/03/2014) (Accessed 24/06/2014)

http://www.streetmap.co.uk/map



these water features are fed and whether they relate to surface water or groundwater flows. However, it is expected that due to the underlying ground conditions and groundwater having been reported at depths of between 6 m below ground level and 15 m below ground level that these are surface water features and not groundwater features. Further investigations into the specifics of the recharge mechanism for the waterbody are therefore not currently required as the ground investigation information assessed suggests that these are likely to be surface water features.

3.2.9. There are five additional ponds which are located immediately adjacent to the Order Limits.

3.2.10. It is proposed that the Gas Connection will cross the Trent and Mersey Canal via the existing Canal Bridge 101 (Malkin’s Bridge), as shown in Figure 3.2. To the east of the Trent and Mersey Canal, there are six field drains identified from OS maps. One of these field drains feeds the surface waterbody located to the north of the Order Limits and adjacent to the Northern Access Road.

Figure 3.2: Water Bodies within Order Limits

Geology and Hydrogeology 3.2.11. The British Geological Survey (BGS) Geology of Britain Viewer9 indicates that the MBP is

underlain generally by Devensian Till with a small area of River Terrace Deposits which lies to the west of the Order Limits, and is associated with the River Trent. The River Terrace Deposits do not underlie any of the proposed buildings associated with the Scheme.

3.2.12. The bedrock underlying and within the Order Limits is composed primarily of the Halesowen Formation (mudstone, siltstone and sandstone) with linear areas running north west to south east of Halesowen Formation (sandstone). The geological map records the presence of Made Ground deposits across most of the central part of the Order Limits.

3.2.13. There are two geological faults shown on the BGS mapping in the northern and southern tip of the Order Limits, orientated east-west both downthrown to the north.

9 British Geological Survey, 2014 Geology of Britain Viewer [online] Available at: http://www.bgs.ac.uk/discoveringGeology/geologyOfBritain/viewer.html [Accessed on 15/06/2014]

http://www.bgs.ac.uk/discoveringGeology/geologyOfBritain/viewer.html



3.2.14. The Halesowen Formation underlying the Order Limits and the River Terrace Deposits immediately to the west of the Order Limits are designated by the Environment Agency10 as Secondary A Aquifers capable of supporting water supplies at a local rather than strategic scale, and in some cases forming an important source of base flow to rivers. This suggests the strata are permeable.

3.2.15. The Devensian Till is designated by the Environment Agency to be Unproductive Stratum. These are rock layers or drift deposits with low permeability that have negligible significance for water supply or river base flow.

3.2.16. Borehole logs produced by Halcrow12 indicated the presence of perched groundwater in the Made Ground within the MBP Site and the top of the underlying superficial deposits at depths of approximately 1 m to 2 m bgl.

3.2.17. The Environment Agency mapping indicates that approximately 300 m to the west of the Order Limits, lies a Zone 3 (Total Catchment) Source Protection Zone (SPZ), defined by the Environment Agency as the area around a source within which all groundwater recharge is presumed to be discharged at the source.

3.3. Existing Infrastructure Canals and Artificial Waterways

3.3.1. The Trent and Mersey Canal (the Canal) is located along the eastern extent of the Order Limits.

3.3.2. The Environment Agency highlights the Canal as an area with a high chance of pluvial flooding. The area of flood risk does not appear to deviate from the Canal, and so the overall risk is considered low. However the Canal is up topographic gradient of the Order Limits and is therefore considered further in this document.

Drains 3.3.3. As confirmed by the Scheme's site specific Foul and Surface Water Drainage Strategy

(document reference 6.4.9, Appendix 14.3) no piped positive drainage system or land drainage ditches are present within the Order Limits. According to the topographical survey, any run-off from within the Order Limits is conveyed by overland flow from east to west towards the River Trent and its flood plain adjacent to Meaford Road. Infiltration is a minor means of surface water drainage within the Order Limits. The existing private surface water networks all drain from east to west across the Order Limits discharging directly into the River Trent.

Sewers 3.3.4. Severn Trent Water (STW) public sewer records included within the Foul and Surface Water

Drainage Strategy (document reference 6.4.9, Appendix 14.3) demonstrates there are no public gravity sewers or public surface water sewers within or in close proximity to the Order Limits.

3.3.5. The Foul and Surface Water Drainage Strategy demonstrates that existing private sewer records indicate a number of foul and surface water networks within the Order Limits.

3.3.6. The existing private foul water sewer network drains in a south westerly direction across the Order Limits and continues west along the south perimeter of the Barlaston electricity substation, discharging into a Sewage Treatment Works to the west of Meaford Road, ultimately discharging into the River Trent. This network and the sewage treatment works appears to have not been used for some time due to no development being undertaken on the MBP Site since the former Meaford 'A' and 'B' Power Stations were demolished.

3.3.7. The existing private surface water networks all drain from east to west across the Order Limits. Two networks continue in a south westerly direction and outfall into the existing River Trent flood plain to the west of Meaford Road. Two other networks continue west around the northern perimeter of the Barlaston electricity substation and outfall directly into the River Trent.

Flood Defence Structures 3.3.8. The SFRA demonstrates that there are no flood defence structures serving the River Trent within

the vicinity of the Order Limits.

10 Environment Agency. What’s in my backyard? (Accessed 3/03/14)



Reservoirs 3.3.9. According to the Environment Agency Flood Map three reservoirs are located in the surrounding

area - The Black Lake at Knowl Wall Farm is at NGR 385749, 339316 approximately 5 km north west of the Order Limits; the Trentham Gardens Lake is at NGR 386974, 339439 approximately 5 km north west of the Order Limits; and the Serpentine is at NGR 389354, 355430 approximately 20 km north of the Order Limits.

3.4. Current Flood Classification 3.4.1. This section of the FRA has been prepared to identify potential sources of flooding and the likely

mechanisms by which flooding could occur. The MBP Site, including the land within the Order Limits, is currently derelict with various excavations and stockpiles of soil and rubble associated with the demolition of the former Meaford 'A' and 'B' power stations along with large areas of hard standing. Any run-off from land within the Order Limits is conveyed by overland flow from east to west towards the River Trent and its flood plain adjacent to Meaford Road. Infiltration is a minor means of surface water drainage from land within the Order Limits and surrounding area. Potential sources of flooding and associated mechanisms as identified for review in the Level 1 FRA are as follows:

• river (fluvial) sources - potential flooding resulting from watercourses near to the site or from the sea;

• groundwater flooding - potential flooding as a result of rising groundwater levels;

• overland/surface water (pluvial) flooding - potential flooding as a result of surface water flows from adjacent land;

• sewers and drains - potential flooding resulting from sewers or drains;

• reservoir/lake flooding - potential flooding resulting from overtopping or bursting of reservoirs or lakes; and

• infrastructure - potential flooding as a result of failed or burst water mains.

3.4.2. In the following sections of the FRA, these scenarios have been discussed and the flood risks to the Scheme are examined in more detail.

3.4.3. River (Fluvial) Flooding

3.4.4. According to the latest Environment Agency flood map for this area and the correspondence with the Environment Agency (dated 17/04/2014 and included in Appendix A of this document), the Order Limits are located outside those areas defined as being at risk of flooding from rivers and/or sea as shown on Figure 3.3. A small area within the Order Limits is located adjacent to the River Trent at the Scheme’s proposed surface water drainage outfall to the River Trent (see work numbered 6 within Schedule 1 to the Order (document reference 3.1)) and is therefore located in the flood plain of the River Trent (Flood Zone 3).

3.4.5. A model of the proposed drainage system has been developed using MicroDrainage WinDes as part of the foul and surface water drainage strategy (document reference 6.4.9, Appendix 14.3). This includes the pipe network, the retention pond and flow control. Simulation results show that the system operates within the required performance parameters in terms of maximum discharge rates and flooding. It is possible that the Scheme outfall may be surcharged by flooding from the River Trent. This situation has been simulated with a 1 in 100-year +20% rainfall event and the results show that no potential flooding will occur and therefore the FRA considers this no further in the assessment.

3.4.6. Correspondence from the Environment Agency (see document reference 6.4.9 14.1(a)) states that the flood risk from the Canal and the unnamed watercourse will need to be assessed as part of this FRA.



Figure 3.3: Environment Agency Flood Map

(Reproduced with permission from the Environment Agency January 2015)

3.4.7. The MEC Site, excluding the surface water outfall to the River Trent, is considered to be at low risk of fluvial flooding. Nevertheless, further consideration has been given to fluvial flooding in the following sections of this FRA. The flood risk to and from the surface water outfall is discussed further in section 3 (Level 2 Flood Risk Assessment section) of this FRA.

Flood Risk Vulnerability and Flood Zone Development Compatibility 3.4.8. In terms of flood risk vulnerability, the Scheme is classified as “Essential Infrastructure” which

covers essential utility infrastructure, including electricity generating power stations and grid and primary substations. The SFRA states that “the Sequential Test should be carried out to demonstrate that there are no reasonably available sites in areas with less risk of flooding that would be appropriate to the type of development or land use proposed”.

3.4.9. The MEC Site is located in Flood Zone 1 (Table 2.1). It is noted that the Scheme is suitable for Flood Zones 1, 2, 3a and 3b (Table 2.3). The Flood Risk Vulnerability and Flood Zone ‘Compatibility’ table in the SFRA defines that on the grounds of flood risk the development of this Scheme would be appropriate in Flood Zones 1 and 2 with no exception test and 3a and 3b with the requirement of an exception test.

History of Flooding 3.4.10. The River Trent CFMP details that the area has a long history of river, tidal and surface water

flooding with the earliest reports dating back to 530 A.D. The most significant river flooding on record occurred in February 1795, on the River Trent at Burton on Trent, Nottingham and Newark.

Groundwater Flooding 3.4.11. Groundwater flooding generally occurs during intense, long-duration rainfall events, when

infiltration of rainwater into the ground raises the level of the water table until it exceeds ground levels. Groundwater flooding may take weeks or months to dissipate as groundwater flow is



much slower than surface water flow and water levels thus take much longer to fall. Groundwater flooding is sporadic in time and location, but when it does occur, it usually lasts longer than surface water flooding and interferes with property and infrastructure (such as roads). Groundwater levels may also rise as a result of reactivating springs.

3.4.12. The ground investigation (GI) undertaken in 2007 by Halcrow11 on the MBP Site indicated the presence of perched groundwater in the Made Ground and the top of the underlying superficial deposits at depths of approximately 1 m to 2 m bgl. Within the Halesowen Formation, groundwater was typically present at a depth of 6 m to 15 m bgl. The Halesowen Formation was not considered to be saturated, and the groundwater was not considered to be in hydraulic continuity with the perched water.

3.4.13. The Foul and Surface Water Drainage Strategy (document reference 6.4.9, Appendix 14.3) identified the Order Limits as not currently having a piped positive drainage system or land drainage ditches and that infiltration is a minor means of surface water drainage in the area.

3.4.14. The superficial deposits overlying the majority of the Order Limits are composed of Devensian Till classified by the Environment Agency as Non-Productive Strata due to low permeability. As a result of the low permeability, vertical flow within the Order Limits is likely to be limited so preventing infiltration to the underlying aquifer.

3.4.15. The SBC SFRA suggests that after consultation with the Environment Agency there are no known problems with flooding from groundwater within Stafford Borough which includes the land within the Order Limits.

3.4.16. There is a potential risk of perched water within the Made Ground affecting the Scheme during periods of high rainfall and consideration of this may be required when constructing the Gas Connection. There is no identified risk of groundwater flooding across the Order Limits resulting from rising groundwater. Due to the potential risk of groundwater flooding from the potential perched water within the Made Ground, further consideration has been given in Section 4 of this document; however this risk is considered to be low.

Overland Pluvial Flooding 3.4.17. Pluvial and overland flooding results when rainfall fails to infiltrate the surface and travels over

the ground surface. This is exacerbated by low permeability urban development or low permeability soils and geology (such as clayey soils). Overland flow is likely to occur at the base of slopes and low points in terrain. Local topography and built form can have a strong influence on the direction and depth of flow. The design of a development down to a micro-level can influence or exacerbate this. Overland flow paths should be taken into account in spatial planning for urban developments. In addition, surface water flooding can be exacerbated if development increases the percentage of impervious area.

3.4.18. The Environment Agency (see Figure 3.4) has identified that there is a high (3.3% annually) risk of flooding along the eastern extent of the Order Limits along the Trent and Mersey Canal, the north-western edge of the Order Limits along Meaford Road and a small area within the north-eastern area of the Order Limits. These areas correspond to depressions within the Order Limits or in the case of the area in the north relating to the historical profile of the ordinary watercourse.

3.4.19. Areas of low (0.1 – 1% risk annually) to medium (1 – 3.3% annually) risk of surface water flooding are identified along the western area of the Order Limits associated with the meandering of the River Trent and spanning across the Order Limits from east to west with a scattered distribution as identified on the Environment Agency‘s Flood Online Map.

3.4.20. The highest points within the Order Limits are to the north and east. This suggests that rainfall to this area is likely to flow west towards the River Trent as suggested in the Foul and Surface Water Drainage Strategy (document reference 6.4.9, Appendix 14.3), along the drainage channel associated with Meaford Road. Dips in the landscape appear to be present within the Order Limits acting as pools for draining water while the Trent and Mersey Canal also acts as a pool along the eastern extent of the Order Limits. The low points in and surrounding the Order Limits may be subject to surface water ponding (flooding) during periods of intensive rainfall and eventually promote flow to the western extent of the Order Limits and to the River Trent. The areas identified as being at risk of surface water flooding are consistent with the nature of overland flows with flooding likely to occur at the base of escarpments.

11 Halcrow Group Limited, March 2008. Meaford Business Park, Stone, Staffordshire: Geo-Environmental Assessment, Internal Report



3.4.21. Surface water flooding may be exacerbated if development increases the impervious area. It has the potential to change the surface water flow regime within the Order Limits. The Scheme area is greater than 1 hectare and the construction of new areas of hardstanding may prevent natural infiltration and increase surface run-off. Temporary ground alteration or compaction within the Order Limits may also lead to the same consequences. Consideration may be necessary to control such flood risks, particularly as materials or machinery are to be stored in such areas.

3.4.22. The MBP Site is known to contain a large proportion of unproductive superficial strata which will prevent infiltration. The MBP Site also contains Made Ground, which may allow excess water to partially infiltrate the ground and drain as perched water reducing the overall quantity of rainfall remaining as surface water run-off.

Figure 3.4: Risk of Overland/ Pluvial Flooding


3.4.23. It is recognised that development may increase the risk of flooding both within the Order Limits and in the surrounding area by reducing infiltration and increasing both the volume and speed of run-off. Whilst historically the land within the Order Limits was developed, the structures have been demolished and therefore the area is currently undeveloped and it is likely that, without any mitigation, the Scheme would have the potential to increase flood risk. Further consideration of this source of flooding is required, and is discussed further in Section 4.

Sewer Flooding 3.4.24. Flooding may occur when the sewerage infrastructure becomes overwhelmed by heavy rainfall

(due to inadequate capacity) or blockages in drainage systems (such as silt or debris accumulation). Works above or adjacent to existing sewer networks may also potentially lead to flooding as a result of damage during excavations or damage causing blockages below ground.

3.4.25. A sewer modelling report for the MBP Site was completed by Severn Trent Water (STW) in 2007, summarised in the Halcrow drainage strategy and flood risk assessment12. The modelling undertaken by STW aimed to determine what affect the development of the MBP would have on

12 Halcrow Group Limited, November 2007. Meaford Business Park, Drainage Strategy and Flood Risk Assessment



the present sewers. Modelling was undertaken using an ‘InfoWorks’ hydraulic model of the Barlaston sewerage system upstream of the discharge point, using data obtained from the UADMS sewer records database. The system was modelled using multiple simulation runs of 1, 2, 5, 10,20, and 30 year returns and summer storms of 15, 30, 60, 90, and 120 minute duration.

3.4.26. The Halcrow drainage strategy and flood risk assessment summarised that connecting a development in accordance with the extant planning permission on the MBP Site, a flow of 27.78 l/s to the existing sewer would not have an adverse effect on the existing public sewerage system.

3.4.27. STW were contacted as part of the 2014 foul and surface water drainage strategy for the Scheme. The strategy states that:

• “In order to accept the proposed foul water flows (1l/s domestic, 6l/s trade effluent) the local sewage network in the village of Meaford would need upgrading including works to the Sewage Pumping Station (SPS) and possibly a new larger rising main (approximately 1km long); and

• Modelling work of the local sewage network in the village of Meaford would be recommended if a connection for the total discharge of 7l/s is required”.

3.4.28. The detailed design of the proposed foul and surface water drainage systems for the Scheme must comply with the parameters and principles defined within the Foul and Surface Water Drainage Strategy (document reference 6.4.9, Appendix 14.3). The pipe work downstream of the proposed outfall connection for the Scheme will be investigated post granting of the Order to establish the extent of any de-silting or refurbishment that may be required to provide a good outfall to the River Trent. In addition discussions with STW regarding the proposed pumping station and rising main should be concluded to establish the scale of the works that are required.

Infrastructure Failure Flooding (Canals, Artificial Waterways, Reservoirs and Lakes)

3.4.29. Infrastructure which retains water or transmits or controls flows (i.e. canals, reservoirs, Sustainable Drainage System (SuDS) features, dams, water supply pipelines or other water bodies) near a development has the potential to fail and cause flooding. During flood conditions it is possible that other water bodies will experience the effects of increased rainfall. If these assets are not able to cope during these conditions, and overtop or fail, flooding may occur.

Canals and Artificial Waterways 3.4.30. The Trent and Mersey Canal (Canal) is present along the eastern extent of the Order Limits.

Figure 3.4 highlights the Canal as an area with a high chance of pluvial flooding. The area of flood risk does not appear to deviate from the Canal, and so the overall risk is considered low. However, the Canal is up topographic gradient of the Order Limits and has been considered further in section 4 of this document.

Reservoirs/Lakes 3.4.31. When reservoirs and lakes flood, there can be implications beyond the immediate area of the

waterbody. Flooding may increase the flow downstream, as larger than usual volumes of water may flow from the flooded waterbody. This may present a flood risk downstream, creating flash floods with little warning. Flooding from reservoirs is considered very unlikely (see Figure 3.5).

3.4.32. Environment Agency flood risk maps (Figure 3.5) indicate that the Black Lake, Knowl Wall Farm is approximately 5 km north-west of the Order Limits, the Trentham Gardens Lake is approximately 5 km north-west of the Order Limits and Serpentine is approximately 20 km to the north of the Order Limits.

3.4.33. Whilst reservoir flooding is extremely unlikely to occur, the Environment Agency’s flood mapping shows that flooding as a result of a failure to Trentham Gardens Lake and Black Lake could occur along the River Trent and impact the area to the west of the Order Limits. As the land within the Order Limits is up topographic gradient, the impact from reservoir flooding is not considered any further.



Figure 3.5: Environment Agency Reservoir and Lakes Flood Map


3.4.34. The risk of flooding from the nearby reservoirs / lakes is considered negligible as the flooding extent is shown by the Environment Agency to remain to the east of Meaford Road and outside of the Order Limits. This form of flooding is therefore not considered further in this document.

3.5. Climate Change 3.5.1. The River Trent CFMP considers climate change will have a great impact on the flood risk. Up to

a 20% increase in peak flow in all watercourses is expected, increasing the probability of large-scale flood events. The number of people at risk during a 1% flood event is expected to reach 134,206 within the catchment.

3.5.2. However, the CFMP for the West Staffordshire sub-area (which covers the Order Limits) considers the flood risk as a result of climate change to not increase considerably.

3.5.3. The potential impacts of climate change need to be considered and accommodated in the development for future sustainability. A precautionary approach should be applied to the Scheme by recognising the need for flood storage and mitigation and adaption to changing environmental conditions.



4. Level 2 Flood Risk Assessment 4.1. Assessment of Flooding 4.1.1. The sources of flooding highlighted in government guidance13 have been considered at the

scoping level. The Level 1 FRA and Section 2 of this document conclude that:

• Tidal Flooding – The MEC Site is located inland, and therefore tidal flooding will not be discussed further;

• River Flooding (Fluvial) – The MEC Site is considered at a low risk, with most of the Order Limits located in flood zone 1, however the western most extent of the Order Limits at the River Trent outfall is located in Flood Zone 3. The modelling of the proposed drainage system show that the system operates within the required performance parameters in terms of maximum discharge rates and flooding and as such the Scheme does not increase the risk to fluvial flooding from the inflow of drainage from the MEC Site. In addition correspondence with the Environment Agency states that the flood risk from the ordinary watercourse will need to be assessed as part of any supporting flood risk assessment therefore fluvial flooding has been discussed further;

• Groundwater Flooding – Perched water has been identified within the Order Limits, and any ground works below ground surface may be at risk;

• Surface Water (Overland) Flooding – The Environment Agency indicates several areas at a medium risk of flooding within the Order Limits and the proposed Scheme is likely to change the surface water flow regime for the MEC Site therefore further assessment is required;

• Sewer Flooding – The detailed design of the proposed Foul and Surface Water Drainage Strategy (document reference 6.4.9, Appendix 14.3) for the Scheme must comply with the parameters and principles defined within the foul and surface water drainage strategy. The pipe work downstream of the proposed outfall connection will be investigated post granting of the Order to establish the extent of any de-silting or refurbishment that may be required to provide a good outfall to the River Trent. In addition discussions with STW regarding the proposed pumping station and rising main should be concluded to establish the scale of the works that are required. No further assessment is proposed;

• Canal and Artificial Waterways Flooding – The risk of flooding from canals and artificial waterways is assessed in this section of this document;

• Reservoir / Lake Flooding – Land within the Order Limits is not impacted from reservoir flooding, the impact from reservoir flooding is therefore not considered any further in this document. The risk of flooding from groundwater, overland flow and canals has been highlighted as a potential risk and has been assessed in this section of this document.

River (Fluvial) Flooding 4.1.2. According to the latest Environment Agency flood map for the relevant area of land within the

Order Limits and the correspondence with the Environment Agency (dated 17/04/2014 and included in Appendix A), the Order Limits are located outside those areas defined as being at risk of flooding from rivers and/or sea as shown on Figure 3.3Error! Reference source not found.. A small area of land within the Order Limits is located adjacent to the River Trent. This is at the surface water drainage outfall to the River Trent which is therefore located in flood zone 3. Works may be required to reinstate the current drainage system and the outfall to the River Trent. Whilst these works (works numbered 6 in Schedule 1 to the Order, document reference 3.1) would be carried out in flood zone 3, it is anticipated that any replacement infrastructure would be below ground. Therefore, there would be no change to the ground surface elevation within this flood zone following the completion of the works and therefore no change to flood risk.

4.1.3. During construction where ground is excavated and infrastructure installed the excavation and construction material and equipment should be stored outside flood zones 2 and 3 to ensure there would be no reduction in flood plain storage, damage to equipment or loss of materials should a flood event occur.

13 Planning Practice Guidance, accessed here: http://planningguidance.planningportal.gov.uk/

http://planningguidance.planningportal.gov.uk/



4.1.4. Correspondence with the Environment Agency (dated 17/04/2014 and included in Appendix A), states that the flood risk from the unnamed watercourse will need to be assessed as part of this FRA. The unnamed watercourse originates in the fields to the north of the Order Limits and flows underneath the Trent and Mersey Canal towards Meaford Road. The unnamed watercourse flows into the Order Limits at its northern extent and enters a pond which is outside the Order Limits. This pond is adjacent to the existing MBP Site entrance on Meaford Road. The outfall from the pond passes under the Northern Access Road through an extended culvert (>50 m length). This then flows in a south-west direction through the north-western part of the Order Limits underlying the area of the existing tennis courts and the Barlaston Bowls and Tennis Club and then discharges to the River Trent.

4.1.5. The MEC Site topographical survey indicates that the ground levels in the area of the pond and unnamed watercourse are approximately 98 m AOD. The distance between the watercourse and the southern extent of the Order Limits is approximately 650 m with a ground elevation of approximately 98 m AOD. As the land within the Order Limits slopes in a westerly direction towards the River Trent. Accordingly, it is highly unlikely that the Scheme would increase the flood risk to the unnamed watercourse on the basis that surface water run-off will be managed in accordance with the Foul and Surface Water Drainage Strategy (document reference 6.4.9, Appendix 14.3) for the Scheme. In this way, surface water run-off will be to the River Trent downstream of the watercourse.

4.1.6. A comparison of flood risk vulnerability and flood zone compatibility indicates that the Scheme is in an appropriate location as it is located in Flood Zone 1 (with the exception of the outfall to the River Trent, which is below ground level) and less than 0.1 % risk annually of flooding. As such, there is no requirement for the sequential or exception tests to be applied in relation to fluvial flooding.

4.1.7. Accordingly, the MEC Site is considered to be at low risk of fluvial flooding with the implementation of the measures detailed in the Foul and Surface Water Drainage Strategy (documents reference6.4.9, Appendix 14.3).

Groundwater Flooding 4.1.8. Borehole logs produced by Halcrow in the 2007 GI survey indicated the presence of perched

groundwater in the Made Ground and the top of the underlying superficial deposits which underlie the Scheme, at depths of approximately 1 m to 2 m bgl.

4.1.9. During periods of intense rainfall, perched water levels within the Made Ground may rise as water infiltrates through the deposits. This form of flooding is considered very low risk as a result of the low permeability superficial deposits overlying the majority of the Order Limits preventing infiltration.

4.1.10. The replacement of the more permeable Made Ground with hardstanding (less permeable material) is likely to reduce infiltration to groundwater, alter groundwater flow path and increase surface water run-off. The management of the surface water run-off from the impermeable areas proposed within the Order Limits will be controlled by the implementation of a site specific Foul and Surface Water Drainage Strategy (document reference 6.4.9, Appendix 14.3) and is discussed further below.

4.1.11. With respect to the superficial deposits beneath the Made Ground and their propensity for groundwater flooding it should be noted that the deposits are of low permeability and designated as Unproductive Strata by the Environment Agency. This means there is no hydraulic connectivity between the perched water and bedrock aquifer, preventing the infiltration from impacting the flow regime of the Secondary A bedrock aquifer. In addition, the groundwater was typically present at depths between 6 m and 15 m bgl and is therefore highly unlikely to present an impact in relation to groundwater flooding.

4.1.12. In addition, the Stafford Borough Council SFRA suggests that after consultation with the Environment Agency there are no known problems with flooding from groundwater within Stafford Borough, which includes land within the Order Limits.

Overland Flow/Pluvial Flooding 4.1.13. It is recognised that developing sites where it is proposed to increase impermeable areas, there

is the potential to increase run-off, particularly where permeable and/or vegetated surfaces are replaced with impermeable surfaces which incorporate drainage designed to remove water rapidly. This may lead to increased risk of pluvial flooding and increased flood magnitude down-gradient of the Scheme.



4.1.14. The Environment Agency indicates that an area to the north-west of the Order Limits is at high risk of flooding along with a small area in the centre of the Order Limits and two small areas cross-cutting the Gas Connection route. This area is shown in Figure 3.4 above. A low to medium risk is demonstrated, across the southern extent of the Order Limits with approximately nine small areas scattered within the Power Station Complex footprint.

Existing Surface Water Drainage Arrangements 4.1.15. As described in the Foul and Surface Water Drainage Strategy (document reference 6.4.9,

Appendix 14.3) and indicated by the topographical survey, run-off from land within the Order Limits is conveyed by overland flow from east to west towards the River Trent and its flood plain adjacent to Meaford Road. Infiltration is a minor means of surface water drainage from land within the Order Limits. The existing private foul water sewer network drains in a south-westerly direction across the Order Limits and continues west around the southern perimeter of the Barlaston substation, out-falling into a sewage treatment works to the west of Meaford Road, ultimately discharging into the River Trent. The status of this network and the sewage treatment works appears disused.

4.1.16. The existing private surface water networks all drain from east to west across the Order Limits. Two networks continue in a south-westerly direction and outfall into the existing River Trent flood plain to the west of Meaford Road. Two other networks continue west around the northern perimeter of the electricity substation and outfall directly into the River Trent. The Foul and Surface Water Drainage Strategy (document ref 6.4.9, Appendix 14.3) confirms that there is no evidence of a piped land drainage network or any existing drainage ditches within the Order Limits.

4.1.17. The Foul and Surface Water Drainage Strategy (document ref 6.4.9, Appendix 14.3) calculated the existing run-off flow rate generated from land within the Order Limits in its current condition using IH124 Flood Estimation for Small Catchments with modifications as described in the Interim Code of Practice for Sustainable Drainage Systems. Further details can be found in the Foul and Surface Water Drainage Strategy. The calculations were undertaken using MicroDrainage Source Control with the parameters set out immediately below, with the results presented in Table 4.1 below.

• Area: 2.946 hectares

• SAAR (Standard Annual Average Rainfall): 800 mm

• Soil: 0.45

• Urban: 0

• Region: 4

Table 4.1: Existing Surface Water Run-off Rates

Return period Flow rate (l/s) Run-off rate (l/s/ha)

1 in 1-year 12.6 4.3 1 in 2-years 13.6 4.7 QBAR* (1 in 2.33-years)

15.1 5.2

1 in 30-years 29.6 10.2 1 in 100-years 58.7 20.2

* QBAR: Annual average flow rate

4.1.18. In accordance with Environment Agency requirements, the maximum permitted discharge rate from the Scheme into the existing private system and ultimately into the River Trent will be limited to the annual average existing run-off rate (QBAR) of 15.1 l/s. This flow rate will apply for all rainfall events up to and including the 1 in 100-year +20% event.

Site Drainage and Run-off 4.1.19. Pluvial flooding can be exacerbated if development increases the impervious area as a result of

potential changes to the surface water flow regime at a site. As it is considered that the low permeability superficial deposits (Devensian Till) prevent infiltration from acting as a major means



of surface water drainage within the Order Limits, surface water management is required to control surface water drainage.

4.1.20. The Environment Agency requires SuDS to be considered for the Scheme and, as such, SuDS techniques have been identified as being suitable using the selection process defined in CIRIA C697 The SuDS Manual14. The Scheme is wholly industrial and therefore according to CIRIA C697 all SuDS techniques are considered acceptable.

4.1.21. Whilst ground conditions in some areas of the Order Limits may be hydraulically favourable for infiltration as opposed to run-off, infiltration has not been deemed a viable means of surface water disposal for the Scheme due to the potential risk of mobilising pollutants due to the previous use of the MBP Site as the former coal-fired Meaford 'A' and 'B' power stations.

4.1.22. In order to reduce the impact of the Scheme upon the rate and volume of run-off, the design of the surface water management system must ensure a drainage diversion into the local watercourse and retain the natural state of the groundwater and surface water interaction identified to currently exist within the Order Limits. Therefore the proposed Foul and Surface Water Drainage Strategy replicates existing site drainage and accounts for and above 1 in 100-year rainfall events. The proposed Foul and Surface Water Drainage Strategy comprises a single element:

• All run-off from impermeable areas such as roofs, hardstanding and highway areas shall be drained using a piped system via a retention pond and control chamber, out falling into an existing manhole within a private network; ultimately discharging downstream via a 450 mm diameter pipe into the River Trent.

4.1.23. The performance requirements for the proposed surface water drainage system are as follows:

• the maximum discharge rate into the River Trent will be limited to 15.1/s during free outfall conditions including the 1 in 100-year +20% event; and

• any flooding occurring within the proposed Scheme area for up to and including the 1 in 100-year +20% event must be contained within the MEC Site.

4.1.24. A vortex flow control (e.g. Hydrobrake) is proposed as a control chamber to ensure that the flow rate does not exceed 15.1 l/s. This flow rate is applicable when free outfall conditions are present (when the River Trent is not in flood). The surface water drainage system must also be capable of managing the scenario when the River Trent is flooding and hence the outfall is fully submerged. Under such circumstances the discharge rate from the system will be at least limited if not reduced to zero. Both free and surcharged outfall scenarios have been simulated and the results are described below.

4.1.25. The modelled results for the free outfall scenario in the Foul and Surface Water Drainage Strategy (document ref 6.4.9, Appendix 14.3.) show that there is no flooding for all events up to and including the 1 in 100-year +20% rainfall event, with a total peak discharge rate of 14.7 l/s. The analysis of the surcharged outfall scenario used a water level of 89.75 m AOD, which is the 1 in 100-year +30% flood level on the River Trent. The simulation results show that there is no flooding up to and including the 1 in 100 year +20% rainfall event. Therefore the surface water run-off from land within the Order Limits will not increase the risk of flooding to or from the Scheme.

Canals 4.1.26. Figure 3.4 demonstrates a high risk of surface water/pluvial flooding posed along the stretch of

the Trent and Mersey Canal (Canal), which stretches along the eastern extent of the Order Limits. The areas demonstrated as having high risk of canal flooding are not within the Order Limits. Nevertheless, the Canal has been considered as it is at a higher level than the Power Station Complex.

4.1.27. The Gas Connection is to be constructed over the Canal via an existing canal bridge crossing (Canal Bridge 101, Malkin's Bridge) and as such the design of this structure will ensure access and water flow are not impeded such that water backs up and the Canal overtops.

4.1.28. There is no available information on future flood risk from the Canal. However, the risk is considered minimal as the Environment Agency mapping demonstrates no direct risk. However, during periods of extreme rainfall, it is possible that the assessed area of flooding may expand and create run-off which would be likely to flow downhill and impact on land within the Order

14

CIRIA, 2007, The SuDS Manual, C697



Limits. Overtopping of the Canal in an extreme event could produce excess surface water run-off to the eastern extent of the Order Limits. This run-off would be directed via the Canal’s existing overspill weirs into the local surface water drainage system and then into the River Trent with any additional flow following existing topographically controlled routes as illustrated through the topographic survey included in the Foul and Surface Water Drainage Strategy (document ref 6.4.9, Appendix 14.3). Any flows reaching the Power Station Complex will be intercepted by the associated surface water drainage facilities and directed via the attenuation feature into the River Trent as detailed in the Foul and Surface Water Drainage Strategy.

4.2. Application of Flood Risk Policy Compliance with NPPF

4.2.1. As outlined in Section 2 of this document, the broad aim of NPPF is to reduce the number of people and new properties within the natural and built environment at risk of flooding. To achieve this aim, planning authorities are required to ensure that flood risk is adequately addressed during the initial planning stages of any development.

4.2.2. Responsibility for the assessment lies with the developer who must demonstrate the following:

• Whether the proposed scheme is likely to be affected by flooding;

• Whether the proposed scheme will increase flood risk to adjacent properties; and

• That the measures proposed to deal with any residual flood risks are sustainable.

4.2.3. The developer must prove to the relevant planning authority and the Environment Agency that any existing flood risk or flood risk associated with the proposed scheme can be satisfactorily managed.

4.2.4. In the context of the Scheme, as works within the Order Limits lie fully within Flood Zone 1 being an area of low risk of flooding (with the exception of the outfall to the River Trent, which is below ground), the Scheme is therefore considered to be at low risk of fluvial flooding. As such, the exception test would not be required and the location of the Scheme is appropriate in terms of flood risk.

Demonstration of Flood Risk Management 4.2.5. The flood risks that could affect the Scheme have been discussed in detail in the preceding

sections of this document and the main risks of flood are from groundwater, overland flow and canals.

4.2.6. It is anticipated that surface water run-off and resultant pluvial flooding will be managed by the implementation of the site specific Foul and Surface Water Drainage Strategy (document ref 6.4.9, Appendix 14.3).

4.2.7. Liaison with Severn Trent Water and regulating authorities should continue with respect to the potential flood risk from local sewers in combination with the production and implementation of the Scheme’s Foul and Surface Water Drainage Strategy.



5. Conclusions and Recommendations 5.1. Conclusions 5.1.1. This FRA concludes that the following sources of flood risk will not require further assessment

and are unlikely to present a risk to the Order Limits and surrounding area:

• River flooding (fluvial) – works proposed within the Order Limits fall within flood zone 1 (with the exception of the outfall to the River Trent, which is below ground level). Accordingly, it is at low risk from fluvial flooding, and hence will not require further assessment or the implementation of additional mitigation measures beyond those outlined in the Foul and Surface Water Drainage Strategy (document ref 6.4.9, Appendix 14.3) as described in this document.

• Coastal/ tidal flood risks – the Order Limits is not near the sea.

• Sewer flooding – the Order Limits contains no active sever network.

• Infrastructure failure – land within the Order Limits is not impacted by the potential flood risk from reservoirs or lakes and therefore is not considered at risk of this source of flooding.

5.1.2. The risks that this document has considered further include:

• Groundwater flooding – perched water is identified within the Made Ground and the top of the underlying superficial deposits at approximately 1 to 2 m bgl upon the low permeability superficial Devensian Till deposits. These act as an aquitard overlying the bedrock aquifer within the Halesowen Formation. Increased impermeable material associated with the Scheme (buildings, hardstanding) are expected to further decrease the potential infiltration into the Made Ground directing water as run-off and preventing large volumes entering the perched water and causing rising of the water table and leading to localised groundwater flooding as a result of the hydraulic discontinuity between the Made Ground and the underlying strata.

• Overland/ Pluvial Flooding - with the design and implementation of the Foul and Surface Water Drainage Strategy (document ref 6.4.9, Appendix 14.3) surface run-off from the land within the Order Limits will be managed allowing all surface water to drain into the River Trent imitating the existing site drainage and discharge. The drainage system will also manage the discharge rate into the river ensuring that no cumulative flood implications are observed downstream of the Order Limits.

• There is a potential risk of flooding associated with the adjacent Trent and Mersey Canal on the eastern extent of the Order Limits. The flooding is identified to remain outside of the Order Limits as it has been assessed as being up-gradient of the Order Limits. Overtopping in extreme rainfall events may cause run-off to enter onto land within the Order Limits. The risk of this form of flooding is considered very low as the Canal contains banks which present a peak in the topography which would contain the majority of water influx resulting from a rise in the Canal’s water level. Any excess flows, not dealt with by the Canal’s own water management system, reaching the Power Station Complex will be dealt with by the associated surface water drainage system for the Scheme.

5.2. Recommendations 5.2.1. Continued liaison should be undertaken with Severn Trent Water regarding local drainage and

sewerage systems to ensure the construction works for the Scheme will not result in damage to existing water infrastructure.

5.2.2. The Foul and Surface Water Drainage Strategy (document ref 6.4.9, Appendix 14.3) should be followed, implementing the measures described during the construction phase of the Scheme to allow management of the surface water and foul water and to avoid the risk of flooding within the MEC Site and surrounding areas throughout construction and the continued operation of the Scheme.

5.2.3. Where necessary, appropriate procedures will be followed should the diversion of pipelines be required. In addition, appropriate consents and agreements will be in place before construction works for the Scheme commence in accordance with the Foul and Surface Water Drainage Strategy (document ref 6.4.9, Appendix 14.3).



Appendix A. Correspondence with the Environment Agency

© Atkins Ltd except where stated otherwise. The Atkins logo, ‘Carbon Critical Design’ and the strapline ‘Plan Design Enable’ are trademarks of Atkins Ltd.

Anna Butler Atkins Ltd The Axis 10 Holliday Street Birmingham B1 1TF

[email protected] Telephone +44 (0) 1214835000

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