13 Hydrology, Flood Risk and Drainage · 13.1.2 This chapter presents information related to...

E n v i r o n m e n t a l S t a t e m e n t | Land at Cotes, Loughborough

H y d r o l o g y , F l o o d R i s k a n d D r a i n a g e | 1

13 Hydrology, Flood Risk and Drainage

13.1 Introduction

13.1.1 The proposals for residential-led, mixed use development on land to the east of

Loughborough and to the north and east of the village of Cotes are described in Chapter 2

of the Environmental Statement (ES).

13.1.2 This chapter presents information related to surface water (hydrology), groundwater

(hydrogeology) and flood risk, as part of the Environmental Impact Assessment (EIA).

13.1.3 The potential environmental impacts associated with the issues covered in this chapter cross

over with other parts of the EIA. In particular it is recommended that this chapter is read in

conjunction with Chapter 7 (Ecology and Nature Conservation). The chapter should also be

read in conjunction with the site specific Flood Risk Assessment report that is included in

Volume 2 (Appendix 13.1).

13.1.4 Information has been collected from a variety of sources to provide a baseline review of

hydrology and hydrogeology. Informed by the baseline assessment, receptors of potential

environmental effects associated with surface and sub-surface hydrology arising from the

proposed development have been identified. Mitigation measures have been identified and

residual effects evaluated.

13.1.5 The assessment covers both the construction and operational phases of the proposed

development.

13.2 Assessment Approach

Introduction

13.2.1 The core development (i.e. residential, local centre, employment land, school, sewage

treatment works) is located within a core development area referred to as the “development

area” in this chapter. The extent of the development area is as shown in the illustrative

masterplan (Figure 2.2).

13.2.2 The proposed development includes a number of infrastructure improvements outside of the

development area, including: highway improvements to the junction of Stanford Lane and

Meadow Lane (at Stanford on Soar); the creation of a new pedestrian/cycle link between

Cotes and Allsops Lane; and, with respect to the A60 Nottingham Road - raising road levels

and installing flood relief culverts between Cotes and Loughborough, and re-aligning the

road to the south of Cotes.

13.2.3 The locations of these infrastructure improvements has required the definition of a wider

development “red-line” area shown on Figure 1.1 and the Parameters Plan (Figure 2.1). The

red-line area is referred to in this chapter as “the site”.

13.2.4 The site is considerably larger than the development area. In particular, it includes an area

of land to the west of the development area in which no built development will take place

aside from the junction improvement at Stanford on Soar. The impact of the proposed

development on this area of land is limited to the junction works.

Methodology

13.2.5 Surface and sub-surface receptors potentially susceptible to environmental impact from

flooding and drainage issues associated with the proposed development have been

identified. The identification of receptors has been informed by an assessment of baseline

conditions.

Land at Cotes, Loughborough | E n v i r o n m e n t a l S t a t e m e n t

2 | H y d r o l o g y , F l o o d R i s k a n d D r a i n a g e

13.2.6 The EIA has been informed by a site specific Flood Risk Assessment (FRA) (ref: 13.1)

undertaken in 2013. The FRA report is presented in Appendix 13.1. The FRA was prepared

in accordance with the National Planning Policy Framework (NPPF) and assesses the risk of

flooding from a variety of potential sources including fluvial flood risk, the risk of flooding

from the failure of water impounding structures such as reservoirs and canals, groundwater

emergence and from surface water. The FRA also includes details of the existing drainage of

the site and presents a surface water drainage scheme.

13.2.7 As noted above, the proposals include the installation of a new packaged sewage treatment

plant (PTP) to treat foul water (sewage) from the development (and potentially, existing

dwellings in Cotes which currently discharge sewage to septic tanks and/or cess pits). A foul

water drainage strategy (FWDS) has been developed in support of the proposals and the

EIA has been informed by the FWDS report (ref: 13.2) which is presented in Appendix 13.2.

13.2.8 A desk-based study and review of available information has been undertaken to determine

the existing baseline conditions within the study area. The desk-based study was

supplemented by site visits to validate drainage pathways, waterbody characteristics and

potential flooding mechanisms.

13.2.9 Details of the catchment hydrology have been sourced from the Charnwood SFRA (ref:

13.3), National River Flow Archive (ref: 13.4) and the Flood Estimation Handbook (FEH)

(ref: 13.5). A review of historical flooding information in the vicinity of the site has been

sourced from the Charnwood SFRA), the British Hydrological Society (BHS) Chronology of

Flooding (ref: 13.6). Additional flooding information was also provided by the Environment

Agency (EA) (ref: 13.7) whilst modeled flood levels for the River Soar were from the Lower

Soar & Tributaries Strategic Flood Risk Modelling report prepared for the EA in 2012 (ref:

13.8). No river gauging has been undertaken as part of the EIA process as sufficient

information was judged to be available from the aforementioned sources.

13.2.10 Geological and hydrogeological information for the site has been sourced from the Phase 1

site appraisal report (see Appendix 14.1 to the ES; also ref: 13.9;) and associated

EnviroCheck report, from the British Geological Society (BGS) data viewer website (ref:

13.10) and the BGS Infiltration SuDS GeoReport (ref: 13.11). Information on underlying

soil conditions from Cranfield University’s Soilscapes Viewer (ref: 13.12) together with the

aforementioned information sources have been used to assess the risk of groundwater and

surface water flooding, and also to inform the outline surface water drainage scheme for the

proposed development.

13.2.11 Consultation has been undertaken with the EA (regarding flood risk and drainage issues)

and Severn Trent Water (regarding foul water issues).

13.2.12 Informed by the baseline assessment, surface and sub-surface hydrology receptors of

potential environmental effects have been identified. The ‘importance’ of each receptor has

been designated using professional judgment and by reference to the guidance criteria

presented in Table 13.1.

13.2.13 The potential effects and magnitude of effects on each receptor have been identified using

the criteria presented in Table 13.2 (informed by the baseline assessment), professional

experience and stakeholder consultation.

13.2.14 In order to assess the impact significance of the proposed development on the identified

receptors, the characteristics of each identified impact at the construction and operational

stages have been considered in accordance with:

Direction (positive, negative or neutral impact)

Magnitude (the amount or level of impact)

Extent (area in hectares, linear metres)

Duration (in time or related to species life-cycles)

Reversibility (permanent or temporary impact)



Timing and frequency (e.g. related to breeding seasons)

Cumulative impacts (from a number of different sources)

13.2.15 Identified impacts may be significant at the level of importance defined for the receptor, or

at a lesser geographical scale. For example, limited impacts on a watercourse of County

value might be assessed as being significant at a District level.

13.2.16 Thus, the significance of effects has been determined from the importance of the receptor,

the magnitude of the impact and, where appropriate, the likelihood of the effect occurring

using the effect significance matrix presented in Table 13.3.

Table 13.1 Estimating Receptor Importance

Importance Criteria Measures

Very High

International

to National

Receptor has

a high quality

and rarity on

a national or

regional scale

Surface Water:

Designated Salmonid / Cyprinid fishery

High WFD Ecological status

Good WFD Chemical status

Protected under EU or UK habitat legislation (e.g. Site

of Special Scientific Interest, EA Water Protection

Zone, Ramsar site)

Groundwater:

Principal aquifer providing a regionally important

resource or supporting Site protected under EU and UK

habitat legislation

Source Protection Zone 1

WFD status = Good

Flood Risk:

Flood Zone 3a and/or 3b

High

County to

Regional

Receptor has

a high quality

on a local

scale

Surface Water:

Major Cyprinid fishery

Good WFD Ecological status


Species protected under EU or UK habitat legislation

Groundwater:

Principal aquifer providing a locally important resource

or supporting river ecosystem


Good WFD status

Flood Risk:

Flood Zone 2

Medium /

Local to

District

Receptor has

a medium

quality on a

local scale

Surface Water:

Moderate WFD Ecological status


Groundwater:

Secondary aquifer with limited connection to surface

water

Good/Poor WFD status


Flood Risk:

Flood Zone 2

Low

Site

Receptor has

a low quality

and rarity on

a local scale

Surface Water:

Poor/Bad WFD Ecological status

Poor WFD Chemical status

Groundwater:

Unproductive strata

Poor WFD status

Flood Risk:



Flood Zone 1

Table 13.2. Criteria for Estimating the Magnitude of an Effect on a Receptor

Magnitude Criteria Descriptor

Substantial

Adverse

Loss of

receptor or

loss of quality

and /or

integrity of

receptor

Surface Water:

Reduction in WFD class

High risk of pollution from a spillage

Loss or extensive change to a fishery

Loss or extensive change to a designated Nature

Conservation Site

Groundwater:


Loss of, or extensive change to an aquifer

High risk of contamination of groundwater from

polluted runoff

Loss of, or extensive change to groundwater supported

wetlands

Reduction in aquifer recharge

Flood Risk:

100 year flood levels increased by at least 100 mm

and/or

Increase in flood risk due to potential blockage of new

bridges or other hydraulic structures

Increase in extent of flood zones of > 3 ha

Increase in properties at risk of flooding > 100

Increase in people at risk of flooding > 100

Moderate

Adverse

Effect on

integrity of

receptor or

loss of part of

receptor

Surface Water:


Medium risk of pollution from a spillage

Partial loss of productivity of a fishery

Groundwater:


Partial loss, or change to aquifer

Medium risk of contamination of groundwater from

polluted runoff

Partial loss of integrity of groundwater supported

wetlands

Flood Risk:

100 year flood levels increased by 50 - 100 mm

Increase in flood risk due to potential blockage of new

bridges or other hydraulic structures

Increase in extent of flood zones of 1 -3 ha

Increase in properties in Flood Zone 2 and/or 3 of 25 -

100

Minor

Adverse

Measurable

change in

receptor

quality or

vulnerability

Surface Water:

Minor risk of pollution from a spillage

Groundwater:

Low risk of contamination of groundwater from

polluted runoff

Minor effects on groundwater supported wetlands

Flood Risk:

100 year flood levels increased by less than 50 mm

Increase in extent of flood zones of < 1 ha

Increase in properties in Flood Zone 2 and/or 3 of 5-25



Magnitude Criteria Descriptor

Negligible Effect on

receptor but

of insufficient

magnitude to

affect the use

or integrity

Surface Water:

Negligible or no of pollution from a spillage

Groundwater:

No measurable impact on aquifer

Negligible risk of pollution from spillages

Flood Risk:

Negligible change in flood levels (less than +/- 25 mm)

No change in extent of flood zones

Change in number of properties in Flood Zone 2 and/or

3 of <5

Minor

Beneficial

Some

beneficial

effect on

receptor or a

reduced risk

of negative

effect

occurring

Surface Water:

Improvement in WFD class

Groundwater:

Significant reduction in risk of pollution of groundwater

by spillage

Flood Risk:

100 year flood levels reduced by less than 50 mm

Reduction in extent of flood zones of < 1 ha

Reduction in properties in Flood Zone 2 and/or 3 of 5-

25

Moderate

Beneficial

Moderate

improvement

of receptor

quality

Surface Water:


Groundwater:


Major reduction in risk of pollution of groundwater by

spillage

Flood Risk:

100 year flood levels reduced by 50 - 100 mm

Reduction in extent of flood zones of 1 - 3 ha

Reduction in properties in Flood Zone 2 and/or 3 of 25-

100

Substantial

Beneficial

Major

improvement

in receptor

quality

Surface Water:


Removal of existing polluting discharge to or removal

of likelihood of polluting discharge occurring

Groundwater:


Removal of existing polluting discharge to aquifer or

removal of likelihood of polluting discharge occurring

Increase in aquifer recharge

Flood Risk:

100 year flood levels reduced by more than 100 mm

Reduction in extent of flood zones of > 3 ha

Reduction in properties in Flood Zone 2 and/or 3 >100



Table 13.3. Estimating the Significance of Potential Effects

Import

ance

of R

ecepto

r

Very high

Not

Significant

Minor/Moderate Major Severe

High

Not

Significant

Minor Moderate Major

Medium

Not

Significant

Not Significant Minor Moderate

Low

Not

Significant

Not Significant Not

Significant Minor

Negligible

Minor Moderate Substantial

Magnitude of Impact

13.2.17 Mitigation measures have been developed for each identified impact using professional

experience and informed by best practices. The magnitude of impacts following the

application of the identified mitigation measures (i.e. the residual impact) has been

assessed with reference to the extent, magnitude and duration of the effect and

performance against environmental quality standards, again with reference to the criteria

presented in Table 13.2. The significance of the residual (i.e. post mitigation) effects has

been assessed as described above.

13.3 Policy Framework

13.3.1 There is a wide range of international and national legislation relevant to the assessment of

potential impacts to hydrology and drainage. In addition, there are many guidance

documents concerned with mitigating potential impacts.

13.3.2 Relevant documents are listed in Table 13.4 and key documents are summarized in the text

that follows.

Water Framework Directive (2000)

13.3.3 The aim of the WFD (ref: 13.13) is to establish “good ecological and chemical status in all

surface waters and groundwaters”. It also promotes the importance of sustainable water

use. During the implementation process, Local Planning Authorities (LPA) must not act in a

way to compromise the aims of the WFD. The WFD enables LPAs to enforce the control of

diffuse pollution at source. The development proposals must not compromise the potential

for delivering targets or actions set out in River Basin Management Plans (RBMP).

National Planning Policy Framework (2012)

13.3.4 The National Planning Policy Framework (NPPF) and Technical Guidance (ref: 13.14) sets

out the government’s planning policies for England and how these are expected to be

applied.



13.3.5 The NPPF guides local planning authorities (LPA) and decision-takers both in drawing up

plans and as a material consideration in determining applications. It includes policies to

ensure that flood risk is taken into account at all stages in the planning process to avoid

inappropriate development in areas at risk of flooding, and to direct development away from

areas of highest risk. In exceptional circumstances where new development is necessary in

flood risk areas the policy also aims to make it safe, without increasing flood risk elsewhere,

and, where possible, reducing flood risk overall.

13.3.6 The NPPF advocates the use of the risk-based flood risk sequential test to steer new

development to areas at lowest probability of flooding. It also matches the flood risk

vulnerability of a development proposal to appropriate Flood Zones. For example, more

sensitive developments, like hospitals, would not be permitted in areas at high risk of

flooding, although leisure and tourism developments may be allowed.

13.3.7 The NPPF provides details how to include the potential effects of climate change on

development.

13.3.8 The government’s policies on conserving and enhancing the natural environment are

included in the NPPF, and guides local planning authorities and decision-takers on how

major new systems for pollution control and the management of contaminated land should

be taken into account when considering proposals for development.

The Flood and Water Management Act (2010)

13.3.9 The Flood and Water Management Act 2010 (FWMA) (ref: 13.15) implements several key

recommendations of Sir Michael Pitt’s Review of the Summer 2007 floods. It presents a new

approach to the implementation and management of Sustainable Drainage System (SuDS)

including a new approvals and adoption process (due for Commencement in 2014). Once

implemented, planning applications for new developments would have to be accompanied

by a SuDS application which will be assessed by a SuDS Approval Body.

Water Resources Act (1991)

13.3.10 The Water Resources Act 1991(ref: 13.16) sets out the regulatory controls and restrictions

that provide protection to the water environment through controls on abstractions,

impounding and discharges, as well as identifying, amongst other things conservation,

water quality and drought provisions. The Act is supplemented by The Environment

Protection Act 1991 which established the Environment Agency and The Environment Act

1995 which provides for integrated pollution control.

Table 13.4: Relevant key legislation, policy and guidance documents

Context Legislation, Policies and Guidance Documents

International

Water Framework Directive 2000/60/EC

EC Dangerous Substances Directive 2006/11/EC and daughter directives

EC Freshwater Fish Directive 76/659/EEC and daughter directives

Drinking Water Directive 98/83/EC

National

policy

Water Act 2003 (as amended 2003)

Water Environment (Water Framework Directive) (England and Wales)

Regulations 2003

Control of Pollution (Oil Storage) (England) Regulations (2001)

Groundwater Regulations 1998

Surface Waters [Dangerous Substances (Classification)] Regulations 1998

Control of Substances Hazardous to Health (COSHH) Regulations (2002)

Environment Act 1995 (as amended)

Surface Water (River Ecosystem) (Classification) Regulations 1994



Context Legislation, Policies and Guidance Documents

Land Drainage Act 1991 (as amended)

Food and Environment Protection Act, 1985

Department for Communities and Local Government, The National Planning

Policy Framework, 2012 (and Technical Guidance)

Making Space for Water – Taking Forward a New Government Strategy for

Flood and Coastal Erosion Risk Management in England, March 2005

WEBTAG Unit 3.3.11 The Water Environment Sub-Objective

CIRIA Report 697 (2003) The SUDS Manual

CIRIA Report 609 (2004) Sustainable Drainage Systems – Hydraulic,

structural and water quality advice

CIRIA Report 532 (2001) Control of water pollution from construction Sites

CIRIA Report 522 (2000) Sustainable urban drainage systems – Design

manual for England and Wales

CIRIA Report 156 (1996) Infiltration Drainage – Manual of good practice

CIRIA Report 142 (1994) Control of Pollution from Highway Drainage

Discharges

Code of Good Agricultural Practice for the Protection of Water (the “Water

Code”) (DEFRA 1998 as amended 2002)

Guidelines for the use of herbicides on weeds in or near watercourses and

lakes (DEFRA 1995 PB2289)

Environment Agency (EA) Pollution Prevention Guidelines (PPG), the most

relevant being: PPG 1 – Good environmental practices; PPG4 – Treatment

and disposal of sewage where no foul sewer is available; PPG 5 – Works

and maintenance in or near water; PPG 6 - Working at construction and

demolition sites; PPG 21 - Incidence response planning; PPG 22 - Dealing

with spills

Local policy Borough of Charnwood Local Plan 1991-2006, Adopted January 2004

including Saved Policies: EV/22 Sites of Regional, County and District Level

Ecological or Geological Importance; EV/23 Sites of Parish Level Ecological

or Geological Importance; EV/29 Access to Watercourses for Maintenance

and EV/31 Sewage Disposal Capacity; EV/39 Development and Pollution

Charnwood Local Plan 2006-2028, Core Strategy Pre-Submission Draft,

June 2013 including Policy CS16 - Sustainable Construction and Energy

Charnwood Development Framework, Supplementary Planning Document

(SPD) Charnwood – Leading in Design, Approved by Cabinet July 2005

Other

sources of

information

Environment Agency, Humber River Basin Management Plan, 2009

Environment Agency, River Trent Catchment Flood Management Plan,

December 2010

Charnwood Strategic Flood Risk Assessment, 2008

Environment Agency, Soar Abstraction Licensing Strategy, 2013

National River Flow Archive

Websites for EA, BGS and Cranfield University

Lower Soar Strategic Flood Mapping Study, JBA, 2012

Water Act, 2003

13.3.11 The Water Act 2003 (ref 13.17) formalises Government commitment to the sustainable

management and use of water resources.

Building Regulations (2010) Drainage and Waste Disposal

13.3.12 The Building Regulations Requirement H3 (ref 13.18) stipulates that rainwater from roofs



and paved areas is disposed of by, in order of priority: a soakaway or infiltration system; a

nearby watercourse, or a public sewer. The proposed surface water drainage strategy has

taken account of this order of priority.

CIRIA C697 – The SuDS Manual (2007)

13.3.13 Sustainable Drainage System (SuDS) techniques as described in CIRIA C697 ‘The SuDS

Manual’ (CIRIA 2007) (ref 13.19) aim to deal with surface water as close to the source as

possible and reproduce natural drainage patterns to prevent an increase in the volume and

peak discharge from development sites. CIRIA C697 provides developers with best practice

guidance on the planning, design, construction, operation and maintenance of SuDS.

Sewers for Adoption 7th Edition (2012)

13.3.14 Sewers for Adoption (ref 13.20) provides guidance on the design, construction and

maintenance of drains and sewers outside buildings which are to be adopted by a relevant

public authority.

BS EN 752:2008 – Drain and Sewer Systems Outside Buildings (2008)

13.3.15 BS EN 752 (ref 13.21) provides a framework for the design, construction, rehabilitation,

maintenance and operation of drain and sewer systems outside buildings.

River Basin Management Plan, Humber River Basin District (2009)

13.3.16 The EA Humber River Basin Management Plan (Humber RBMP) (ref 13.22) focuses on

achieving protection, improvement and sustainable use of water and is a requirement of the

WFD. The plan identifies the management of future development as one of the key aspects

which can influence achievement of the WFD requirements.

River Trent Catchment Flood Management Plan (2010)

13.3.17 The EA River Trent Catchment Flood Management Plan (Trent CFMP) (ref 13.23) is a high

level strategic planning document through which the EA will work with other stakeholders to

identify and agree policies for long-term flood risk over the next 50-100 years.

13.3.18 The key points with respect to the Upper Soar and Upper Anker catchment (Sub-Area 9) are

to provide a more accurate and community focused flood warning service, investigate

upstream storage for ‘at risk’ urban centres, including the six small watercourses running

through Leicester, support the production and implementation of an integrated drainage

strategy for urban areas, to reduce the incidence of surface water and foul water flooding by

working with Severn Trent Water Ltd in flood risk management, to investigate opportunities

for creating green corridors along watercourses through urban centres and to identify

mechanisms for achieving this and implement, by working with planners and building

partnerships with local authorities and to investigate flood resilience for infrastructure such

as roads.

Borough of Charnwood Local Plan 1991-2006, Adopted January 2004 (ref: 13.24)

13.3.19 The Adopted Core Strategy includes a list of local plan policies saved. This saved policies

relevant to the water environment are: EV/22 Sites of Regional, County and District Level

Ecological or Geological Importance; EV/23 Sites of Parish Level Ecological or Geological

Importance; EV/29 Access to Watercourses for Maintenance and EV/31 Sewage Disposal

Capacity; EV/39 Development and Pollution. These are summarised below:

Policy EV/22 states that development which would affect a regional, county or district

level ecological or geological site will only be granted where there is a strategic need

for the development sufficient to outweigh the importance of the site for nature

conservation.



Policy EV/23 states “Planning permission for development in and around parish level

ecological and/or geological sites will not be granted unless measures are included to

protect or compensate for valuable habitats or features damaged or destroyed during

the development.”

Policy EV/29 states “Planning permission will not be granted for development within 8

metres of the top of the bank or within 8 metres of the landward toe of a flood bank

or other flood defence on all main rivers and other watercourses which would obstruct

access for future maintenance.

Policy EV/31 states “Where existing sewage disposal facilities are at capacity planning

permission for new development will not be granted unless it is phased to commence

in accordance with a programme for the improvement or extension of those facilities.

In such circumstances permission will be conditioned to ensure that the development

is not occupied until the required improvements are operational.” The aim of this

policy is to safeguard the quality of water resources through the prevention of

pollution of rivers and watercourses. The policy notes that where windfall or other

development sites not specifically allocated in the plan come forward which could lead

to the overloading of treatment works, it is likely that Severn Trent Water Ltd., under

the terms of the Water Act 1989, will request that development is phased to allow for

the implementation of any necessary works. Also, where new facilities are required

the Council will, in consultation with the Environment Agency and Severn Trent Water

Ltd, investigate the possible provision of sustainable sewage management systems.

Policy EV39 seeks to protect the natural environment from pollution, including through

releases to water, land or air by encouraging development proposals to contain

satisfactory measures to overcome possible pollution issues.

Charnwood Local Plan 2006-2028, Core Strategy Pre-Submission Draft, June

2013 (ref: 13.25)

13.3.20 Policy CS 16 Sustainable Construction and Energy identifies a requirement to adapt to and

mitigate against the effects of climate change by encouraging sustainable design and

construction and encourages residential development to meet the equivalent of Code for

Sustainable Homes Level 5 for water efficiency (80 litres/person/day) and to achieve the

equivalent of BREEAM 3 credits for water consumption as a minimum.

13.3.21 The policy seeks to direct development to locations at the lowest risk of flooding, applying

the Sequential Test and if necessary, applying the Exception Test. Where development is

proposed in flood risk areas, the policy states that mitigation measures must be in place to

reduce the effects of flood water and supports developments which take opportunities to

reduce flood risk elsewhere. Finally the policy requires developments to manage surface

water run off with no net increase in the rate of surface water run off for Greenfield sites.

13.3.22 Charnwood’s Supplementary Planning Document (SPD) - Leading in Design encourage,

promote and inspire higher design standards in development in Charnwood. It promotes

distinctive and vibrant places for people and sets out to reduce the impact on the local

environment by re-using previously developed land and buildings, and introducing

techniques that reduce water and energy use.

13.3.23 With respect to the water environment the SPD states “Features of wildlife and ecological

value, such as existing key habitats, important species, buffer areas, wildlife corridors

greenways) and other landscape features of major importance should be retained and

sensitively incorporated into developments. Site and setting analysis should be used to

identify such features. Major developments and other proposals, where it is appropriate,

should enhance the ecological quality and functioning of the site and surrounding ecological

network by restoring and connecting existing wildlife habitats and creating new ones”.



13.3.24 The SPD encourages the use of SuDS to “limit the waste of water, reduce water pollution

and flood risk relative to conventional drainage systems” by controlling rainwater at source,

the use of Infiltration trenches and filter drains, swales and basins ponds and wetlands,

prior to discharge to a natural watercourse. The document highlights the role of SuDS in

reducing the risk of groundwater pollution and flooding.

13.3.25 The SPD also highlights the importance of water conservation and demand management to

reduce water use, e.g. through the use of spray taps, low flush cisterns, water efficient

appliances and avoiding the use of power showers, as well as the rainwater and grey water

recycling.

Charnwood Strategic Flood Risk Assessment (2008)

13.3.26 The Charnwood SFRA (Ref 13.3) was prepared to inform the council’s Local Development

Framework and Sustainability Appraisal with respect to local flood risk issues and the

location of future development in the Borough through the use of a sequential, risk-based

approach to assessing development and flood risk.

13.3.27 The overarching aim of the SFRA is to provide a framework for the management of flood

risk by ensuring that all new development is located in areas of lowest flood risk and where

not possible that there is appropriate justification and that there is sufficient mitigation to

prevent an unacceptable increase in flood risk to people and property. The SFRA was

informed by hydraulic modelling of the River Soar (although this modelling has since been

superseded by more recent modelling undertaken in 2012 as part of the Lower Soar

Strategic Flood Mapping Study).

13.3.28 The SFRA recommended that surface water drainage for large new developments is

considered strategically during site masterplanning, followed by more specific design as

segments are brought forward for development and that surface water runoff from new

developments should be adequately managed through the use of Sustainable Drainage

Systems.

13.4 Scoping Criteria

13.4.1 The Pegasus Group, on behalf of Jelson Limited and Davidsons Developments Limited,

consulted Charnwood Borough Council (CBC) in January 2013 and requested a Screening

and Scoping opinion in accordance with Regulations 5 and 13 of the Town and Country

Planning (Environmental Impact Assessment) Regulations 2011.

13.4.2 The Screening and Scoping report submitted to the Council identified the principal hydrology

and drainage issues to be addressed by the EIA as (i) an assessment of floodplain extents

and (ii) surface water management.

13.4.3 Following consultation with the EA, CBC confirmed (5th March 2013) that the contents of

the Scoping Report were considered acceptable. Following this, the EA consultation

response was received (7 March 2013).

13.4.4 This chapter of the ES has therefore been prepared in accordance with the scope set out in

the aforementioned Scoping Report and takes into account the comments of the EA made in

its letter of 7 March 2013.

13.5 Limitations

13.5.1 This chapter has been prepared to support the planning application for the proposed

development as shown on the Parameter Plan (Figure 2.1) and illustrative masterplan

(Figure 2.2) and is based on a desktop study supported by site visits and stakeholder

consultation. No specific monitoring, field measurements or site investigations have been

undertaken as part of the EIA process.



13.5.2 The assessment is based on outline design information for the surface water and foul water

drainage systems (not detailed design).

13.6 Baseline Conditions

Site Description and Context

13.6.1 For the purposes of this assessment, there are four principal watercourses in the vicinity of

the site: (i) the River Soar to the west; (ii) an unnamed watercourse (which for the

purposes of this assessment is referred to as “Spinney Brook”) which runs through the site;

(iii) an unnamed drain to the south of the site; and (iv) Kings Brook, which passes through

the western edge of the site to the south of Stanford on Soar. There is also a small

fishpond, called Fishpond Spinney” located 250 m north-east of Park Farm on Spinney

Brook. The watercourses are shown on Figure 13.1.

13.6.2 The River Soar flows in a north-westerly direction past the site, whilst the three smaller

watercourses, which are all tributaries of the River Soar, flow in a south-westerly direction.

The land in the vicinity of the site generally slopes from east to west (towards the Soar

valley) from a height of 71 m Above Ordnance Datum (AOD) to 35 m AOD. A ground terrain

model derived from LiDAR data is presented in Figure 13.2.

Figure 13.1. Water Bodies in Vicinity of the Site

Main River

Ordinary watercourse

Confluence

Legend

Unnamed Watercourse

Riv

er S

oar

King

s Br

ook

Unn

amed

Wat

erco

urse

(“Sp

inne

y Br

ook”

)

Herm

itage B

rook

River Soar



Figure 13.2. Site Topography



River Soar

13.6.3 The River Soar is a significant tributary of the River Trent. From its source, south-east of

Hinckley, the river follows a northerly course towards its confluence with the River Trent

near Ratcliffe on Soar, south-west of Nottingham. There are a number of important

tributaries, including the rivers Sence and Wreake and the Rothley, Black and Kingston

brooks.

13.6.4 The River Soar is a predominantly lowland watercourse. The Soar catchment covers an area

of approximately 1,380 sq km, covering much of the county of Leicestershire, together with

small areas of south Nottinghamshire and north-east Warwickshire. Located near the centre

of the catchment, the principal urban area is the City of Leicester. Other significant towns

include Wigston, Melton Mowbray, Loughborough and Kegworth.

13.6.5 According to the River Trent Catchment Flood Management Plan (ref: 13.23), the River

Soar valley is characterised by wide floodplains and terraces. The geology is generally

Keuper Marl combined with beds of Triassic Sandstone. Soils are typically loamy clay with

impeded drainage; this can result in significant amounts of rainfall becoming surface water

run-off. Flooding results from lack of capacity in the river channels and the floodplains

becoming inundated.

13.6.6 The River Soar floodplain upstream of the site is approximately 1.5 km wide, although it

reduces to a width of approximately 1 km adjacent to the site, and narrows further between

the site and Stanford on Soar. In the vicinity of Cotes, the river runs along the eastern

edge of the floodplain with the ground rising steadily further east. Almost the entire

floodplain at this point is to the west of the river (i.e the left bank – looking downstream).

13.6.7 The A60 Nottingham Road crosses the floodplain from Cotes to the east of Loughborough.

The road is embanked across the floodplain and there are a number of culverts under the

embanked road to allow floodwater to pass downstream.

13.6.8 According to the FEH CDROM v3.0, the Soar catchment upstream of Cotes is 1,133 sq km.

the catchment is relatively rural (8% urbanised) but does contain the city of Leicester. The

baseflow index (BFIHOST) for the catchment is 0.4 indicating that a relatively small

proportion of flow in the river is sustained by groundwater.

13.6.9 The River Soar is gauged at Pillings Lock (Station reference 28093 – Soar at Pillings Lock),

2.8 km south of Cotes with continuous flow records available for the period 1986 to the

present day. The NRFA data sheet for the gauging station is presented in Appendix 13.4.

13.6.10 The River Soar is a designated Main River.

Spinney Brook

13.6.11 Spinney Brook is a small, ungauged watercourse that rises approximately 2.5 km north-east

of Cotes near the village of Hoton and drains a catchment of approximately 4 sq km. The

brook flows in a predominantly westerly direction to its confluence with the River Soar to

the west of Cotes (NGR 455111 320957).

13.6.12 According to the FEH CDROM v3.0, the catchment is less than 3% urbanised. The baseflow

index (BFIHOST) for the catchment is 0.45 indicating that a relatively small proportion of

flow in the brook is sustained by groundwater.

13.6.13 The brook is designated an Ordinary Watercourse and responsibility for its maintenance

rests with riparian landowners and the local lead flood authority (Leicestershire County

Council).

Unnamed Drain

13.6.14 The unnamed drain is a small, ungauged watercourse that rises approximately 3.4 km east



of Cotes near the village of Burton on the Wolds. The channel drains a catchment of

approximately 6 sq km which includes Wymswold Airfield. The watercourse flows in a

predominantly westerly direction to its confluence with the River Soar 900 m south of Cotes

and 550 m south of the B676 Barrow Road (NGR 455577 320093).

13.6.15 According to the FEH CDROM v3.0, the catchment is approximately 4% urbanised (Burton

on the Wolds). The baseflow index (BFIHOST) for the catchment is 0.43 indicating that a

relatively small proportion of flow in the brook is sustained by groundwater.

13.6.16 The brook is designated an Ordinary Watercourse and responsibility for its maintenance

rests with riparian landowners and the local lead flood authority (Leicestershire County

Council).

Ponds

13.6.17 An ecological assessment of the fishpond on Spinney Brook is presented in Chapter 7.

Baseline Survey Information

Water Quality

13.6.18 In 2009 the EA adopted the EU WFD classification of water quality. The WFD Classification is

based on over 30 measures and uses a “one out, all out” methodology whereby the poorest

individual result drives the overall result (Environment Agency, 2011).

13.6.19 For surface waters there are two separate classifications for water bodies: ecological and

chemical. For a water body to be in overall good status both ecological and chemical status

must be at least good.

13.6.20 Ecological classification comprises: the condition of biological elements (e.g. fish

populations); concentrations of supporting physico-chemical elements (e.g. oxygen or

ammonia levels); concentrations of specific pollutants (e.g. copper) and hydro-

morphological quality (i.e. hydrology and morphology).

13.6.21 Ecological status is recorded on the scale of high, good, moderate, poor or bad. High

denotes largely undisturbed conditions and the other classes represent increasing deviation

from this natural (reference) condition. The ecological status classification for the water

body, and the confidence in this is determined using the worst scoring quality element.

13.6.22 Chemical status is assessed by compliance with environmental standards for chemicals that

are listed in the Environmental Quality Standards Directive 2008/105/EC. These chemicals

include priority substances, priority hazardous substances and eight other pollutants carried

over from the Dangerous Substance Daughter Directives. Chemical status is recorded as

good or fail and is determined by the worst scoring chemical.

13.6.23 The reach of the River Soar that passes alongside the Site (WFD name “River Soar from

Rothley Brook to Long Whatton Brook” ; water body reference GB104028047211)

commences near Rothley approximately 8 km south of the Site and continues to Normanton

on Soar, approximately 3.2 km north-west of the Site. According to EA data, the area

draining to this reach is 73 sq km. The reach includes the right bank tributary, Spinney

Brook.

13.6.24 Details of the current status of the water body as included in the Humber RBMP are

presented in Appendix 13.4. Key characteristics are summarised below:

The water body is not assigned as a heavily modified water body.

Overall status of Poor ecological status (Figure 13.3).

Overall chemical status is Good



Poor due to Moderate Ammonia levels and Poor Phosphate levels (all other measures

are High).

Overall hydromorphological status: Hydrology, Not High; Morphology, Good.

Biological status - Good for invertebrates, Poor for Fish.

The waterbody has a target of High chemical status by 2015.

Not designated a salmonid water under the EC Freshwater Fish Directive.

13.6.25 The River Soar is a Local Wildlife Site.

13.6.26 The development site is within a nitrate vulnerable zone as defined under the EC Nitrates

Directive, i.e. is in an areas that drains into nitrate polluted waters, or waters which could

become polluted by nitrates. However, the controls relate principally to a reduction in the

use of agricultural fertilizers and as such are not relevant to the proposed development.

Figure 13.3. WFD Water Quality

Surface Water Abstractions

13.6.27 According to the EnviroCheck report there are no surface water abstractions within 1,000 m

of the site.

Ground Conditions and Hydrogeology

13.6.28 According to the Phase 1 site appraisal report (Appendix 14.1) the solid geology comprises

mudstones interbedded with sandstone and siltstones (Mercia Mudstone Formation). BGS

mapping indicates that the superficial deposits consist of varyingly clay, silts, sand and

gravel across the Site.

13.6.29 The EA uses aquifer designations consistent with the WFD. These reflect the importance of

aquifers in terms of groundwater as a resource for drinking water and its role in supporting

rivers, lakes and wetland ecosystems. The aquifer designation is in two categories -

Moderate ecological quality

Poor ecological potential

Application site boundary

Legend

© Environment Agency copyright and database rights 2013© Ordnance Survey Crown copyright. All rights reservedEnvironment Agency, 100026380

http://en.wikipedia.org/wiki/Nitrate



superficial (drift) and bedrock, and aquifers are then classified according to whether they

are principal or secondary.

13.6.30 According to the EA Groundwater Vulnerability Map (see Figure 13.4 and Figure 13.5) the

site is underlain by a Secondary B and/or Secondary undifferentiated superficial aquifer and

a Secondary B bedrock aquifer. Secondary B aquifers are predominantly lower permeability

layers which may store and yield limited amounts of groundwater due to localised features

such as fissures, thin permeable horizons and weathering. They are not strategically

important but may provide water on a local scale.

13.6.31 The Soar Licensing Abstraction Management report (ref: 13.27) states that the vast

majority of bedrock outcrop in the Soar catchment relates to the predominantly clay based

Mercia Mudstone group which provides very inconsistent groundwater resources. The report

states that there are no large areas of aquifer and no principal aquifers of any note in the

catchment although there may be some locally important sources.



Figure 13.4. Superficial Aquifers

Figure 13.5. Bedrock Aquifers

Legend

Principal

Secondary A

Secondary B

Secondary (Undifferentiated)

© Environment Agency copyright and database rights 2013© Ordnance Survey Crown copyright. All rights reserved

Environment Agency, 100026380, 2013

Legend

Principal

Secondary A

Secondary B

Secondary (Undifferentiated)

© Environment Agency copyright and database rights 2013

© Ordnance Survey Crown copyright. All rights reservedEnvironment Agency, 100026380, 2013



Groundwater Quality

13.6.32 The achievement of good status in groundwater involves meeting a series of conditions

which are defined in the WFD. In order to assess whether these conditions are being met, a

series of tests have been designed for each of the quality elements defining good (chemical

and quantitative) groundwater status.

13.6.33 There are five chemical and four “quantitative” tests, the latter being an expression of the

degree to which a body of groundwater is affected by direct and indirect abstractions. Each

test is applied independently and the results combined to give an overall assessment of

groundwater body chemical and quantitative status. The worst case classification from the

relevant chemical status tests is reported as the overall chemical status for the groundwater

body and the worst case classification of the quantitative tests reported as the overall

quantitative status for the groundwater body. The worst result of these two is reported as

the overall groundwater body status. Groundwater is classed as having good or poor status.

13.6.34 According to the Humber RBMP, the underlying groundwater body, the Soar – Secondary

Combined unit (reference GB40402G990600) is assessed to have a good overall status

based on both its quantitative and its qualitative status.

13.6.35 According to the RBMP the main pressures facing the aquifer are due to hazardous

substances and other pollutants from point sources and pesticides, and from high nitrate

levels.

Groundwater Abstractions

13.6.36 The site is not within a Source Protection Zone and according to the Envirocheck report

there no extant licences for groundwater abstractions within 1,000 m of the site.

Flood Risk

Fluvial Flood Risk

13.6.37 A site specific flood risk assessment has been undertaken to assess flood risk at the

application site from all identified sources to the site, to demonstrate that the development

would be safe for its lifetime and to ensure that the proposed development would not

increase flood risk elsewhere. The FRA report is attached as Appendix 13.1.

13.6.38 The NPPF provides the following definitions for each of the flood zones:

Flood Zone 1: Low Probability. Land assessed as having a less than 1 in 1000 annual

probability of river or sea flooding in any year.

Flood Zone 2: Medium Probability. Land assessed as having between a 1 in 100 and 1

in 1000 annual probability of river flooding or between a 1 in 200 and 1 in 1000

annual probability of flooding from the sea in any year.

Flood Zone 3a: High Probability. Land assessed as having a 1 in 100 or greater annual

probability of river flooding (>1%) or a 1 in 200 or greater annual probability of

flooding from the sea (>0.5%) in any year.

Flood Zone 3b: The Functional Floodplain. Land where water has to flow or be stored

in times of flood. The identification of the functional floodplain should take account of

local circumstance and not be defined solely on rigid probability parameters. However,

land which would flood with an annual probability of 1 in 20 or greater in any year

should provide a starting point for consideration and discussion.

13.6.39 According to the EA flood map (Figure 13.6) most of the development area is in Flood

Zone 1. The exceptions being: (i) a swathe of land associated with the lower reaches of

Spinney Brook in the vicinity of Park Farm, and (ii) an area of land in the field to the north

of the junction of Cotes Road with the B676 Barrow Road, which is associated with the

unnamed drain to the south of the site.

13.6.40 Flood outlines derived from modelled peak flood levels from the Soar model and projected



onto a ground terrain model based on site topographic survey information are very similar

to the flood outlines presented on the EA flood map.

Figure 13.6. EA Flood Map

13.6.41 With regards the wider site, as defined by the red-line, the Stanford Lane / Meadow Lane

junction is in Flood Zone 1(to be improved as part of the proposals) whilst the

pedestrian/cycle link between Cotes and Allsops Lane (which includes a new pedestrian

crossing of the River Soar to the south-west of Cotes) and the location of proposed new

flood relief culverts on the A60 Nottingham Road are in Flood Zone 3.

13.6.42 Although the development area is located almost entirely within Flood Zone 1, and safe dry

access is provided to the site from the A60 Nottingham Road to the north-east, the issue of

access to and from the site from Loughborough via the A60 has been raised as a significant

issue of concern by the EA due to the risk of flooding along the road.

13.6.43 Notwithstanding the above, it is worth noting, however, that the A60 Nottingham Road is

less likely to flood than any other road across the Soar valley in the vicinity of the site, and

no records confirming flooding of the A60 Nottingham Road have been found. In its

consultation response to the EIA Scoping Request, the EA stated: “Several times this winter

2012/13 access to Loughborough from the villages of Cossington, Sileby and Barrow upon

Soar have involved crossing the River Soar at Cotes because normal access routes were

impassable.”

13.6.44 To better understand the risk of flooding along the A60 Nottingham Road between Cotes

and Loughborough, detailed studies have been undertaken using the EA River Soar Model.

This work is summarized below:

The EA River Soar model, developed as part of the 2012 Lower Soar strategic flood

risk mapping study, has been reviewed, under licence.

The model review confirmed that the strategic model lacked a detailed representation

of structures in the floodplain between Cotes and Loughborough, such as raised roads

and underpasses.

FZ3 (1 in 100 yr)

FZ2 (1 in 1,000 yr)

FZ1 (>1 in 1,000 yr)

Main River

Legend

© Environment Agency copyright and database rights 2013© Ordnance Survey Crown copyright. All rights reservedEnvironment Agency, 100026380



The EA model has been improved by incorporating: (i) actual road levels along the

A60 (from topographic survey information); (ii) seven flood culverts along the A60;

(iii) the railway line to the south of the A60, and (iv) the five underpasses beneath the

railway line to the south of the A60.

The updated EA model has been formally reviewed and approved by the EA.

The updated model confirmed that a considerable length of the A60 is flooded

between Cotes and Loughborough for the 1 in 100 year plus climate change event and

that the average depth of flooding is approximately 380 mm.

The extent and depth of flooding was significantly lower for less extreme events, with

no flooding observed for the 1 in 50 year event or less.

13.6.45 The modeling work described above is described in more detail in a modeling report which

was submitted to the EA for review in March 2013. The EA formally accepted the work in

July 2013. The modeling report is an Appendix to the site specific FRA (ref: 13.1).

Groundwater Flooding

13.6.46 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. It is most common in low-lying areas overlain by permeable soils and

permeable geology, or in areas with a naturally high water table.

13.6.47 According to the Soilscapes maps produced by the National Soils Research Institute (Figure

13.7) the site is underlain by loamy and clays soils. For the most part, the soils have impeded

drainage and would be prone to waterlogging. The exception is an area associated with

loamy soils which are indicated to extend along the right bank of the River Soar in the

vicinity of Cotes which are indicated to be free draining.

13.6.48 The BGS GeoReport indicates that for potential groundwater levels vary across the site but

may be less than 3 m below ground level (bgl) for at least part of the year. BGS

groundwater susceptibility mapping (Figure 13.8) is consistent with this, indicating that

susceptibility levels vary across the site but is generally moderate to high.



Figure 13.7. Underlying Soil Conditions

Figure 13.8. Susceptibility to Groundwater Flooding

Loamy/clayey soils, impeded

drainage

Loamy/clayey floodplain

soils, naturally wet

Loamy – freely draining soils

Legend

© Crown copyright. All rights reservedDefra 100018880 2008Cranfield University NSRI

© Crown Copyright 2013. All rights reserved. Licence number 100047514Derived from 1:50 000 scale BGS Digital Data, British Geological Survey - NERC

Legend

Susceptibility to flooding from groundwater

Significant

Moderate

Low



Flood Risk from Surface Water

13.6.49 Pluvial flooding results from rainfall-generated overland flow, before the runoff enters any

watercourse or sewer, or where the sewerage/drainage systems and watercourses are

overwhelmed and therefore unable to accept surface water. Pluvial flooding is usually

associated with high intensity rainfall events but may also occur with lower intensity rainfall

where the ground is saturated, developed or otherwise has low permeability resulting in

overland flow and ponding within depressions in the topography.

13.6.50 The EA flood map for surface water (Figure 13.9) provides a general indication of the

broad areas that may be at risk of surface water flooding based on a national assessment

which takes broad account of drainage and typical storms which are likely to cause flooding.

The flood map indicates that the site may be susceptible to surface flooding along Spinney

Brook and the land to the north of the B676 Barrow Road / Cotes Road junction.

13.6.51 Based on the underlying soil conditions, other parts of the site may also be susceptible to

surface water flooding from sustained periods of rainfall or during heavy rainfall, although

the effect would be naturally mitigated by the sloping nature of the site.

13.6.52 Sewer flooding can occur when the capacity of the sewer system is overwhelmed by heavy

rainfall, becomes blocked or is of inadequate capacity, resulting in flooding of land and/or

property. Normal discharge of sewers and drains through outfalls may be impeded by high

water levels in receiving waters. However, there are no public sewers in the vicinity of the

Site so the Site is not assessed to be at risk from sewer flooding.

Figure 13.9. Flood Map for Surface Water

Legend

Flood depths from a 1 in 30year rainfall event

> 0.1m

> 0.3m

Legend

Flood depths from a 1 in 30year rainfall event

> 0.1m

> 0.3m

© Environment Agency copyright and database rights 2013© Ordnance Survey Crown copyright. All rights reservedEnvironment Agency, 100026380, 2013



Risk of Flooding from Other Sources

13.6.53 Reservoir or canal flooding may occur as a result of the facility being overwhelmed and/or

as a result of dam or bank failure. In the unlikely event that a reservoir dam failed, a large

volume of water would escape at once and flooding could happen with little or no warning.

13.6.54 According to the EA website, “Reservoir flooding is extremely unlikely to happen. There has

been no loss of life in the UK from reservoir flooding since 1925. As the enforcement

authority for the Reservoirs Act 1975 in England, the EA ensures that reservoirs are

inspected regularly and essential safety work is carried out.”

13.6.55 The EA Risk of Flooding from Reservoirs Map (Figure 13.10) shows the largest area that

might be flooded if a reservoir were to fail and release the water it holds. This is a worst

case scenario, and, according to the EA website, it is unlikely that any actual flood would be

this large.

13.6.56 The Charnwood SFRA lists no prior records of reservoir flooding at or within the vicinity of

the site.

Historic Flooding

13.6.57 The EA flood history map of the area (Figure 13.11) indicates that the Soar valley between

Loughborough and Cotes experienced extensive flooding in 1960, 1977 and 2000. Flooding

of the floodplain also occurred in November/December 2012. Historic flooding appears to be

confined to the west of the river (left bank) between the river channel and Loughborough

and no flooding of Cotes has occurred. The map confirms that the development area has not

experienced historic flooding.

13.6.58 This is confirmed by the Charnwood SFRA and the British Hydrological Society (BHS)

Chronology neither of which make mention of any records of historical flooding of Cotes /

the development area.

Figure 13.10. Risk of Flooding from Reservoirs


Flooding from reservoirs

Legend



Figure 13.11. EA Flood History Map

Existing Site Drainage

13.6.59 Severn Trent Water’s Asset Protection Team has confirmed that the site is a non mains

sewered area and that there are no mains sewers in the vicinity of the site. The nearest

mains sewers are believed to be in Loughborough approximately 1.3 km from the

development area.

13.6.60 Foul water from the properties in Cotes is believed to discharge to property level septic

tanks and/or cess pits. It is not known whether any of these discharge to Spinney Brook.

Development Receptors

13.6.61 Table 13.5 lists the identified receptors and their importance/scale as assessed using as

guidance the criteria presented in Table 13.1.


1960 event

1977 event

2000 event

Legend



Table 13.5. Development Receptors

Receptor and (in parenthesis) Nature of Impact Receptor Importance

River Soar (Water quality i.e. biological and physico-chemical

quality, hydrology, hydromorphology) High

Spinney Brook (Water quality i.e. biological and physico-

chemical quality, hydrology, hydromorphology) Low

Fish Pond (Water quality) Low

Drainage ditches (Water quality) Low

Aquifer (Water quality) Medium

Site workers (Flood risk) – Construction Phase Very High

Development residents and visitors (Flood risk) – Operational

Phase Very High

Users of the Loughborough / Cotes pedestrian/cycle link (Flood

risk) - Operational Phase Very High

Users of the A60 Nottingham Road - through the River Soar

floodplain (Flood risk) Very High

13.7 Key Impacts and Likely Significant Effects

13.7.1 This section summarises the likely effects of the proposed development during the

construction phase and the operational phase. The assessment of effects is prior to the

implementation of mitigation measures.

Construction Phase

13.7.2 During the construction phase there will be a number of activities which could reduce

surface water quality with respect to physical contaminants. These include:

Materials handling, storage, stockpiling, spillage and disposal;

Earthworks involving manipulation of ground levels and re-engineering of existing

made ground as necessary;

Excavation and foundation construction within the site and site preparation;

Installation of temporary and permanent infrastructure and roads;

Construction of proposed dwellings, commercial units etc;

Construction of drainage runs and utilities duct runs;

Formation of public spaces, public realm and associated restoration and landscaping;

and

Movement and use of static and mobile plant/construction vehicles.

13.7.3 The construction activities may lead to the disturbance and mobilisation of physical

contaminants (i.e. dust, sediments and muds). In particular, during periods of heavy

rainfall, vehicle movements resulting in damage to soil structure may generate increased

sedimentation within surface water runoff. In addition, during periods of dry, windy

weather, wind-blown dusts generated by the excavation of soils have the potential to

directly reduce the quality of surface water features.

13.7.4 These activities may result in sediments directly or indirectly entering surface water

features, impacting on the physical, chemical and biological quality of the surface water

receptors in the surrounding area.

13.7.5 Contaminants, spilled contaminants and suspended sediments have the potential to affect

surface and ground water bodies via surface runoff, shallow interflow and infiltration.

Construction activities such as piling and/or ground excavation may create new pollutant

pathways from the surface to the underlying aquifer.



13.7.6 There is a risk of pollution from foul water from site worker accommodation and sanitary

facilities.

13.7.7 The volume of construction related traffic using the A60 Nottingham Road between Cotes

and Loughborough, and the location of construction activities in areas at risk of flooding

from the River Soar will increase the risk of flooding to people and plant.

13.7.8 Off-site flood risk may increase due to increased runoff due to soil compaction on site.

13.7.9 The likely effects of the proposed development during the construction phase prior to the

implementation of mitigation measures are summarised in Table 13.6.

Table 13.6: Impact Significance during Construction Phase (Pre-Mitigation)

Receptor Value Potential Impact Magnitude of

impact

Significance

of impact

River Soar High Pollution risk Substantial

adverse

Major

adverse

Spinney Brook,

drainage ditches

and fish pond

Low Pollution risk

Substantial

adverse

Minor

adverse

Aquifer

Medium

Pollution risk

Moderate adverse Minor

adverse

Site workers Very High

Risk of flooding Minor adverse Minor to

moderate

adverse

Users of the A60

Nottingham Road

Very High


moderate

adverse

Residents / property

elsewhere

Very High


moderate

adverse

Operational Phase

13.7.10 The possible effects of the proposed development during the operational phase are

summarised below:

The increase in impermeable area and in traffic volumes would increase the risk of

contamination of surface runoff due to spillage of contaminants and from flushing of

pollutants from the impermeable surfaces.

The impermeable area of the site will increase as a result of the proposed

development leading to an increase in peak surface water runoff rates and the total

runoff volumes which would increase flows in watercourses and flood risk

downstream.

The large number of residents and users of the proposed development will increase

the risk of watercourses becoming blocked due to tipping of rubbish etc, leading to

change in flood flow dynamics and an increase in downstream flood risk.

Increased traffic volumes associated with the development will place more people at

risk of flooding from the River Soar due to increased traffic levels along the A60



Nottingham Road between Cotes and Loughborough and also use of the

pedestrian/cycle link.

The new pedestrian/cycle crossing of the River Soar could increase flood risk due to

potential bridge blockage or restriction in channel conveyance capacity.

Foul water from the developed site could pollute the receptor water body.

13.7.11 The likely effects of the proposed development during the operational phase prior to the

implementation of mitigation measures are summarised in Table 13.7.

Table 13.7: Impact Significance during Operational Phase (Pre-Mitigation)

Receptor Value Potential Impact Magnitude of

impact

Significance of

impact


adverse

Major adverse

Spinney Brook,

drainage ditches and

fish pond

Low Pollution risk Substantial

adverse

Minor adverse

Aquifer Medium Pollution risk Moderate

adverse

Minor adverse

Development

residents and visitors

Very High

Risk of flooding Moderate

adverse

Major adverse

Uses of the

pedestrian / cycle

link

Very High


adverse

Major adverse

Users of the A60

Nottingham Road

Very High


adverse

Major adverse


elsewhere

Very High


moderate

adverse

Cumulative Impacts

13.7.12 Other developments in the vicinity of the study area are discussed in Chapter 1. None are

considered to warrant inclusion for further consideration in this chapter of the ES.

13.8 Mitigation, Enhancement and Residual Effects

Construction Phase

13.8.1 Potential impacts on the water environment through the construction phase would be

managed by a range of operational, control and monitoring measures as set out below.

General Practices

13.8.2 Prior to undertaking permanent and temporary works that would affect the River Soar, the

applicant would seek Flood Defence Consent from the EA.

13.8.3 Prior to undertaking permanent and temporary works that would affect the Ordinary

Watercourses on the site, the applicant would seek Flood Defence Consent from

Leicestershire County Council.

13.8.4 As a matter of course:



A Construction Environmental Management Plan (CEMP) would be prepared and

agreed with the LPA. The CEMP will set out the methods by which construction will be

managed to avoid, minimise and mitigate any adverse effects on the water

environment.

The principal contractor would take regard of the relevant EA Pollution Prevention

Guidelines (PPG) in preparation of the CEMP and during the operation of the Site.

All construction works would be designed in accordance with the latest relevant EA

guidelines and the ADAS Technical Note on Workmanship and Materials for Drainage

Schemes (1995) (ref: 13.28).

Method statements would be agreed with the EA to ensure compliance with PPG prior

to the commencement of construction works to ensure that surface runoff quality is

managed during the construction process.

Contractors undertaking earthworks would develop risk assessments and method

statements covering all aspects of their work that have the potential to cause physical

damage to structures (e.g. water supply and sewerage infrastructure), mobilise large

quantities soil/sediments or block open watercourses. Earth moving operations would

be undertaken in accordance with BS 6031: 2009 Code of Practice for Earthworks

(ref: 13.29).

Works affecting soils would follow MAFF’s Good Practice Guide for Handling Soils

(2000) (ref: 13.30) which provides comprehensive advice on soil handling including

stripping, soil stockpiling and reinstatement.

Works would comply with DEFRA guidance in the Construction Code of Practice for the

Sustainable Use of Soils on Construction Sites (2009) (ref: 13.31) which provides

guidance on the use, management and movement of soil on site. This action should

prevent the mobilisation of sediment and prevent pollution of watercourses.

Good practice guidance on erosion and pollution control would be followed, e.g. CIRIA

Environmental Good Practice on Site (C650) (ref: 13.32) and Control of Water

Pollution from Construction Sites (C532) (ref: 13.33).

The principal contractor would avoid the storage of plant, machinery fuel or materials

(including soil stockpiles) alongside watercourses unless unavoidable. Construction

works should be programmed as far as is practicable to minimise soil handling and

temporary soil storage.

The refuelling of plant, storage of fuels and chemicals and overnight storage of mobile

plant would be within the designated contractors compound areas. The compounds

would contain appropriate facilities for the storage of fuels and chemicals i.e. bunded

and locked storage containers, and would also be equipped with spill kits.

13.8.5 The adoption of best practice construction methods and construction management

processes would significantly mitigate many of the identified potential environmental effects

of the construction phase of the proposed development.

13.8.6 The principal contractor may use alternative procedures compliant with their own

Environmental Management System. However, the broad approach and content would as a

minimum be comparable.

13.8.7 Foul water from temporary staff welfare facilities would be contained within sealed storage

vessels and disposed of off-site to minimise the risk of surface or groundwater

contamination.

13.8.8 The principal contractor would avoid the storage of plant, machinery or materials in areas at



risk of flooding would be avoided wherever possible.

Flood Warning

13.8.9 It is recommended that the principal contractor monitors flood warnings from EA flood

warning service for “River Soar at Cotes and Loughborough Moors” and raises flood warning

alarms should flooding be forecasted. A flood management and response plan should be

prepared and all construction staff briefed on the plan as part of the site induction process.

Summary

13.8.10 The magnitude of effects during the construction phase following the application of the

identified mitigation measures (i.e. the residual impact) has been assessed with reference

to the extent, magnitude and duration of the effect; its nature (direct or indirect; reversible

or irreversible); potential interactions between effects; performance against environmental

quality standards and other relevant criteria; receptor sensitivity and compatibility with

environmental policies. Table 13.8 sets out a summary of magnitude of effects.

Table 13.8: Post Mitigation (Residual) Impacts – Construction Phase

Receptor Value Potential Impact Significance of

impact

(Pre-Mitigation)

Mitigation Residual

Significance of Impact

River Soar High Pollution risk Major adverse Operational, control and monitoring measures

Not significant

Spinney Brook, drainage ditches and fish pond

Low Pollution risk Minor adverse Operational, control and monitoring measures

Not significant

Aquifer

Medium

Pollution risk Minor adverse Operational,

control and monitoring measures

Not

significant

Site workers

Very

High

Risk of flooding Minor to

moderate adverse

Operational,

control and monitoring measures

Not

significant

Users of the

A60 Nottingham Road

Very

High

Risk of flooding Minor to moderate adverse

Operational, control and monitoring

measures

Not significant


elsewhere

Very High

Risk of flooding Minor to moderate adverse

Operational, control and monitoring measures

Not significant

Operational Phase

Sequential Approach to Layout

13.8.11 As required by the NPPF and encouraged by Charnwood’s Core Strategy Policy CS16, a

sequential approach has been applied during masterplanning of the site. For example, a

wide no-development corridor is proposed along the course of Spinney Brook for flood risk

management purposes and to protect and enhance the environment in this location. In

addition, all built development, with the exception of a short section of access road is

located in Flood Zone 1.



Finished Floor Levels

13.8.12 To mitigate flood risk from all identified sources, finished floor levels (FFL) of residential

dwellings would be a minimum of 0.15 m above adjacent ground levels.

13.8.13 This FFL would, subject to the implementation of an appropriately designed surface water

drainage scheme, enable any potential surface water to be conveyed safely across the Site

without affecting property in accordance with the approach promoted within Making Space

for Water (2005) (Ref: 13.34).

Watercourse Maintenance

13.8.14 A maintenance and management regime would be implemented to prevent the build up of

debris and/or rubbish in Spinney Brook which could otherwise block natural flows and

increase flood risk.

New Bridges - Design Principles

13.8.15 The soffit level of the new pedestrian bridge over the River Soar will be set to be not less

than the modelled 1 in 100 year plus climate change event plus 600 mm freeboard. The

bridge abutments will be set back a minimum of 1m from the bank top to ensure adequate

conveyance capacity and to provide a wildlife corridor under the bridges.

13.8.16 Where other bridges are concerned, e.g. over Spinney Brook, the same design principles

will be adopted to ensure that flood risk is not increased.

Surface Water Drainage Scheme

13.8.17 The extent of impermeable area at the site will increase by over 40 hectares following

development.

13.8.18 An outline surface water management scheme has been prepared based on the principles of

sustainable drainage (SuDS). The site has been divided into a number of drainage areas

based on natural drainage pathways, and a drainage solution developed for each using

SuDS elements. This approach supports phased development, with surface water runoff

from each phase of the development sustainably managed.

13.8.19 It is expected that the disposal of surface water by infiltration will not be feasible due to

underlying soil conditions and groundwater levels under the site. Therefore, the illustrative

surface water drainage scheme would manage surface water runoff through the provision of

attenuation storage.

13.8.20 Indicative storage volumes have been determined to restrict peak surface water runoff rates

from impermeable areas of the developed site to existing Greenfield rates and to store the 1

in 100 year storm event including a 30% increase in rainfall intensity in order to allow for

the effects of climate change during the lifetime of the development.

13.8.21 It is expected that the attenuation storage would be provided by above ground storage such

as detention basins and/or retention ponds, distributed across the development site,

augmented, if feasible by infiltration basins. The final decision taken during detailed design,

informed by site investigations to confirm sub-surface conditions (permeability). It is

intended that the outfall from these facilities would discharge Spinney Brook.

13.8.22 The proposed scheme would ensure that runoff from the site would not increase following

development and that betterment is provided through an overall reduction in peak runoff

rates post development. This would ensure that that the proposed development would not

increase flood risk elsewhere and could reduce off-site flood risk as encouraged by the

NPPF.

13.8.23 The proposed surface water scheme would improve water quality by the introduction of at

least two treatment trains in accordance with the SuDS Manual. In addition, the surface



water drainage system will incorporate oil and silt traps where required.

13.8.24 Ownership and maintenance arrangements would be confirmed at reserved matters

application stage.

13.8.25 The EA has welcomed the approach taken to the use of SuDS within the proposed surface

water management scheme.

Site Access and Egress

13.8.26 In order to ensure safe dry access to the Cotes development from Loughborough during the

1 in 100 year plus climate change event, the following measures are proposed (see Figure

13.12):

Raise level of A60 Nottingham Road to a minimum of 38.93 m AOD along left bank

floodplain between the railway underpass at Loughborough and River Soar). Current

road levels are in the range 38.46 to 39.04 m AOD.

Construct new culverts with a total combined span of 30 m and depth of 1.5 m along

left bank floodplain (between the railway underpass and River Soar).

Raise level of A60 to a minimum of 39.30 m AOD along right bank floodplain between

River Soar and A60/B676 junction.

Construct a new 5 m by 1 m culvert on right bank of River Soar beneath the new A60

layout at the existing B676/A60 junction.



Figure 13.12. A60 Nottingham Road Flood Mitigation Measures

13.8.27 Implementation of the proposed mitigation measures results in the A60 being dry during the

1 in 100 year plus climate change flood event.

13.8.28 The extent of flooding remains unchanged as a result of the proposed mitigation when

compared to the baseline. There is an increase in flood levels compared to the baseline on a

small area of agricultural land south of the A60/B676 junction. However the average

increase in flood depth is only 45 mm (maximum increase 112 mm) and the extent of the

flooding compared to the existing situation is unchanged due to the topography of the

affected area. This detriment is therefore considered to be minimal off-set by betterment

provided by the provision of a dry route across the River Soar for the 1 in 100 year plus

climate change event.

13.8.29 The modeling work is described in more detail in a report that was submitted to the EA for

review in March 2013. The EA formally accepted the modeling and findings in July 2013.

The modeling report is an Appendix to the site specific FRA (ref: 13.1).

13.8.30 The mitigation measures outlined in the preceding section are consistent with Policy Option

4 of the River Trent Catchment Flood Management Plan (EA, 2010) which states:

“We will work with others to minimise disruption to people and communities caused by

flooding, taking into account future climate change and urban growth.”

“We will work with others to reduce the disruption caused by flooding to transport…”



13.8.31 The mitigation proposals would deliver significant betterment to users/residents of the

proposed development and to residents from surrounding villages to the west of the River

Soar who rely on the A60 during times of flooding and would help deliver the EA catchment

flood management plan policy for the region.

13.8.32 As part of the proposals, the A60 will be realigned to the east of the River Soar bridge. Part

of the new route will cross areas that are, according to the EA flood map in Flood Zone 2

and Flood Zone 3 (due to flood water from the unnamed drain overtopping Barrow Road and

inundating the fields in the location of the proposed road).

13.8.33 To ensure safe access and egress, the proposed road will be raised above the 1 in 1000

year flood level. The volume of water displaced by the road raising during the 1 in 100 year

flood event has been calculated by projecting the EA flood mp outline onto the topographic

survey to determine the average ground level at the flood zone extent. The volume of water

displaced during the 1 in 100 year flood event as a result of the proposed road is 880 m3.

13.8.34 Additional storage outside of the existing 1 in 100 year outline will be provided to

compensate for the lost storage as shown on Figure 13.13. The area outlined in purple is

3,000 m2 and the ground would need to be lowered to a minimum of 41.4 m AOD (300 mm

below the 1 in 100 year estimated flood level).

Figure 13.13. Compensatory Storage – Cotes Road

Flood Warning

13.8.35 The site is not covered by the EA flood warning service. However, it is recommended that

the EA extends the coverage of the service it provides to Loughborough to include the site

so that site residents and visitors awareness of flood risk can be raised by a flood

management plan linked to the warning service.



13.8.36 It is also recommended that signage is placed along the pedestrian/cycle link informing

users that the route is liable to flood to raise awareness.

Foul Water Drainage Strategy

13.8.37 According to pre-application discussions with statutory sewerage undertaker (Severn Trent

Water) Asset Protection Team, the site is in a non-mains sewered area.

13.8.38 As such it is proposed that foul water from the developed site would be treated by a

packaged sewage treatment plant located to the west of the development area, between

Stanford Lane and the River Soar (alongside the allotments).

13.8.39 The location would support the gravity flow of most, if not all foul water to the treatment

works (subject to confirmation at detailed design). The PTP would be located entirely in

Flood Zone 1 in accordance with siting requirements stated in PPG4. The outfall would be to

the River Soar.

13.8.40 The implementation of a PTP would be subject to satisfying the legal requirements regarding

consultation with the local planning authority and statutory sewerage undertaker and

submission of a foul drainage assessment as per DETR Circular 03/99 and WO Circular

10/99 requirements (ref: 13.35).

13.8.41 In addition to the above, PPG4 states:

Any proposals for non-mains sewerage systems must take account of the

requirements of Building Regulations and should be discussed with the local planning

authority at an early stage and well before any planning application is made.

Approval for the construction and installation of a PTP may be needed from the local

authority building control department and would be governed by the Building

Regulations (England & Wales) 2000 (as amended) and guidance “Wastewater

Treatment Systems and Cesspools” The Requirement H2 (ref: 13.36).

Consent for any discharge from a PTP as well as separate permission for the outfall

structure to the River Soar (Main River) would be required from the EA under the

provisions of the Water Resources Act 1991.

Holder of the discharge consent for the PTP would responsible for ensuring that the

plant is well maintained, that the effluent complies with the consent conditions and

that a sampling chamber downstream of the PTP is installed so that representative

samples of the effluent can be sampled.

13.8.42 The effluent quality and volume limits would be set out in the EA consent to ensure that

there is no deterioration in the water quality of the River Soar as a result of any discharge

from the proposed PTP. At a minimum an effluent standard of 20 mg/l Biological Oxygen

Demand, 30 mg/l Suspended Solids and 20 mg/l Ammonia is anticipated.

13.8.43 It is acknowledged that the River Soar is currently failing WFD ecology standards on

ammonia and phosphorus levels. It is recognised that a constructed wetland / reed-bed

system may be required to provide tertiary effluent treatment and further reduce BOD,

ammonia and phosphorus levels, and sufficient space exists in the identified plant location

should a reed-bed system be required. This issue would be discussed with the EA prior to

design and installation of the PTP. If required, the reed bed system would be designed and

maintained in accordance with BRE Good Building Guide No. 42 (ref: 13.37).

13.8.44 Procedures for maintenance of the PTP would be implemented in accordance with best

practice and the system manufacturer’s instructions, carried out by an accredited operator

experienced in dealing with sewage treatment plants.



13.8.45 In addition to the above, water consumption of the development would be managed

through the use of best practice water saving and efficiency measures such as low

consumption dual flush WC cisterns and, in the commercial units, waterless urinals and time

limited tap usage, in accordance with Charnwood Policy CS16.

Summary

13.8.46 The magnitude of effects during the operational phase following the application of the

identified mitigation measures (i.e. the residual impact) has been assessed with reference

to the extent, magnitude and duration of the effect; its nature (direct or indirect; reversible

or irreversible); potential interactions between effects; performance against environmental

quality standards and other relevant criteria; receptor sensitivity and compatibility with

environmental policies. Table 13.9 sets out a summary of magnitude of effects.

Table 13.9: Post Mitigation (Residual) Impacts – Operational Phase

Receptor Value Potential

Impact

Significance

of impact

(Pre-

Mitigation)

Mitigation Residual

Significan

ce of

Impact


adverse

Surface water

drainage scheme;

Foul water

drainage strategy;

Packaged sewage

treatment plant;

Operational

maintenance

Not

significant

Spinney Brook,

drainage

ditches and

fish pond

Low Pollution risk Substantial

adverse

Surface water

drainage scheme;

Foul water

drainage strategy;

Packaged sewage

treatment plant;

Operational

maintenance

Not

significant

Aquifer

Mediu

m

Pollution risk Moderate

adverse

Surface water

drainage scheme;

Foul water

drainage strategy;

Packaged sewage

treatment plant;

Operational

maintenance

Not

significant

Development

residents and

visitors

Very

High

Risk of

flooding

Moderate

adverse

Site layout;

Finished floor

levels; Surface

water drainage

scheme;

Watercourse

maintenance

Not

significant

Uses of the

pedestrian /

cycle link

Very

High

Risk of

flooding

Moderate

adverse

Bridge design;

Flood warning and

awareness

signage

Not

significant



Receptor Value Potential

Impact

Significance

of impact

(Pre-

Mitigation)

Mitigation Residual

Significan

ce of

Impact

Users of the

A60

Nottingham

Road

Very

High

Risk of

flooding

Moderate

adverse

Installation of

flood culverts on

A60; Realignment

and raising of

A60; Flood

warning

Major

beneficial

Residents and

property

elsewhere

Very

High

Risk of

flooding

Minor adverse Surface water

drainage scheme;

Compensatory

storage; Bridge

design

Not

significant

13.9 Summary

Introduction

13.9.1 This chapter presents information related to surface water, groundwater and flood risk, as

part of the Environmental Impact Assessment (EIA). The scope of the assessment has been

determined and agreed through the EIA scoping process. The assessment covers both the

construction and operational phases of the proposed development.

13.9.2 Information from a variety of sources has been assessed to provide a baseline review of

hydrology and hydrogeology. From this, receptors of potential environmental effects arising

from the proposed development have been identified, the effects of the potential

development have been assessed and where required mitigation measures proposed and

residual effects have been identified and evaluated.

Baseline Conditions

13.9.3 There are four principal watercourses in the vicinity of the site, The River Soar and three

small tributaries. The River Soar is a Local Wildlife Site but currently has poor ecological

status. The site is underlain by superficial and bedrock aquifers although they do not have

strategic value for water supply purposes.

13.9.4 The River Soar valley has a history of flooding and agricultural land to the south/west of

Cotes has flooded on several occasions since 1960. However, the flooding is limited to the

Soar valley and Cotes and the development area is located on higher ground and has not

flooded historically. However, some of the highways infrastructure improvements and

associated flood mitigation measures are located in the Soar valley and are at risk of

flooding and small parts of the built development area are indicated to be at a risk of

flooding from two small watercourses.

13.9.5 Safe dry access to the development area is provided by the A60 Nottingham Road to the

north-east. However, detailed modelling work has confirmed that the A60 between Cotes

and Loughborough may flood during extreme events.

13.9.6 The risk of groundwater flooding varies across the site but is assessed to be significant in

places. Parts of the site may also be susceptible to surface flooding. The risk of flooding

from other sources is not assessed to be significant.

Likely Significant Effects

13.9.7 The construction phase has the potential to affect the quality of local waterbodies through

the mobilization of contaminants and sediments, and accidental spillages, and the creation



on new pollutant pathways to the aquifer. On site flood risk would be increased due to the

location of construction activities in areas at risk of flooding from the River Soar, whilst off-

site flood risk may increase due to increased runoff due to soil compaction on site.

13.9.8 During operation of the site the quality of local waterbodies may be affected by surface

runoff polluted by spilled contaminants or flushing of pollutants from impermeable surfaces.

Flood risk may be affected due to the large increase in impermeable areas, due to the

increase in local resident numbers and traffic volumes on the A60 to Loughborough and due

to the new pedestrian crossing of the river Soar.

Mitigation and Enhancement

13.9.9 Potential impacts on the water environment through the construction phase would be

managed by a range of operational, control and monitoring measures including the

implementation of a Construction Environmental Management Plan and best construction

practice. Foul water from temporary staff welfare facilities would be contained within sealed

storage vessels and disposed of off-site. Storage of plant, machinery or materials in areas

at risk of flooding would be avoided wherever possible. Flood risk would be mitigated

through the implementation of a flood management and response plan linked to the EA

flood warning service for the River Soar at Cotes.

13.9.10 A sequential approach to the layout has been adopted. No residential t development will be

located in Flood Zone 1. Flood risk associated with a small (unnamed) drain to the south of

the site will be mitigated by ground raising and compensated for on site. Finished floor

levels of residential dwellings would be raised to mitigate the risk of flooding from all

sources.

13.9.11 The soffit level of the new pedestrian crossing of the River Soar would be not lower than the

1 in 100 year plus climate change event plus 600 mm freeboard. Where other new bridges

are proposed over minor tributaries, these will be designed so as not to increase flood risk

elsewhere.

13.9.12 Surface water from the developed site will be managed by a drainage scheme based on

sustainable drainage principles. Peak runoff rates will be limited to existing Greenfield rates

through the use of a mix of attenuation storage facilities which may include retention ponds,

detention basins and swales. The use of infiltration devices will be investigated further as

part of the detailed design stage. The drainage system will incorporate oil and silt traps

where required and would improve water quality by the use of at least two treatment trains.

13.9.13 A package of flood risk mitigation measures are proposed for the A60 between Cotes and

Loughborough, including highway realignment and the installation of new flood culverts. The

measures would significantly reduce flood risk along the route and provide a safe, dry route

to Loughborough for up to the 1 in100 plus climate change event. This significant

betterment would benefit residents of the development and the wider area that already rely

on this route when other Soar valley crossing points are flooded.

13.9.14 It is proposed that the development is served by a new packages sewage treatment plant,

located to the south of the development area in an area of low flood risk. The plant would

comply fully with EA pollution prevention guidelines and would discharge high quality

treated effluent to the River Soar in accordance with the necessary discharge consents. It is

intended that the plant will also treat foul water from existing properties in Cotes, thereby

enabling existing cess pits and septic tanks to be decommissioned.

Conclusions

13.9.15 The construction phase mitigation measures would significantly reduce the risks to the

identified receptors and the residual significance of the effects is assessed to be not

significant.

13.9.16 There are no identified adverse residual effects during the operational phases of the

development. Flood risk along the A60 Loughborough Road between Cotes and



Loughborough would be reduced due to the implementation of mitigation measures

providing a minor to moderate benefit.



Abbreviations

BGS - British Geological Survey

CAMS – Catchment Abstraction Management Strategy

Charnwood BC – Charnwood Borough Council

DTM - Digital Terrain Model

EA – Environment Agency

ES – Environmental Statement

EIA – Environmental Impact Assessment

FRA – Flood Risk Assessment

FW – Foul Water

FZ – Flood Zone

NPPF – National Planning Policy Framework

PTP – Packaged (sewage) Treatment Plant

RBMP – River Basin Management Plan

SFRA – Strategic Flood Risk Assessment

SPZ – Source Protection Zone

SuDS – Sustainable Drainage System

SW – Surface Water

SuDS – Sustainable Urban Drainage Systems



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https://www.gov.uk/government/publications/code-of-practice-for-the-sustainable-use-of-soils-on-construction-sites

https://www.gov.uk/government/publications/code-of-practice-for-the-sustainable-use-of-soils-on-construction-sites

http://www.ciria.org/service/Web_Site/AM/ContentManagerNet/ContentDisplay.aspx?Section=Web_Site&ContentID=8982

http://www.ciria.org/service/Web_Site/AM/ContentManagerNet/ContentDisplay.aspx?Section=Web_Site&ContentID=8982

http://www.orkneywind.co.uk/advice/SEPA%20Pollution%20Advice/ciria%20c532.pdf

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http://archive.defra.gov.uk/environment/flooding/documents/policy/strategy/strategy-response1.pdf

http://www.tsoshop.co.uk/

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Appendix 13.1 – Flood Risk Assessment report (See Volume 2)



Appendix 13.2 – Foul Water Drainage Strategy report (See Volume 2)



Appendix 13.3 – River Soar at Pillings Lock Gauging Station Data Sheet



Appendix 13.4 – Humber RBMP Water Body Status

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