2.0 Aims and Objectives - Borough of Burnley 0446 Flood... · 2013-12-03 · 2.0 Aims and Objectives 2.1 There are three aims and one objective of the report. The details of which

Site Specific Flood Risk Assessment

Proposed Industrial Units, Empire Business Park, Enterprise Way, Burnley BB12 6LT

DG-A Ltd Page 1 of 15 November 2013

1.0 Introduction

1.1 This flood study report is to accompany a planning application to Burnley Borough Council

for the construction of a new Industrial Unit at Empire Business Park, Enterprise Way, off

Liverpool Road, Burnley BB12 6LT. The map reference for the site is :- SD 81153 432646.

The area of the site is approximately 5.22 hectares

2.0 Aims and Objectives 2.1 There are three aims and one objective of the report. The details of which are set out below. 2.2 Appraisal of the risk

2.2.1 It is proposed to identify land and property which could be at risk and the degree of risk of

flooding from river, sea and other sources in the area.

2.3 Managing the Risk

2.3.1 To comment and advise as to the design of the development so as to avoid flood risk to

people and property and, where possible, manage any residual flooding risk on the proposals,

taking account of the impacts of climatic change.

2.4 Reduction of the Risk

2.4.1 Suggestions will be made to reducing flood risk, if any, and to and from new development

through location, layout and design, possibly incorporating sustainable urban drainage

systems i.e. (SUDS)

2.5 Methodology

2.5.1 This report’s objective is to follow the procedures set out in The Communities and Local

Government Department: Technical Guidance to the National Planning Policy Framework

(March 2012), on development in areas at risk of flooding and accordingly produce a Flood

Risk Assessment specifically for this site. Further information has been obtained from the

Environment Agency, the Lead Local Flood Authority and United Utilities.




3.0 The Site

3.1 The site is close to Burnley Town Centre and its bus links and is also close to Junction 9 off

the M65 Motorway.

Fig. I - Location Plan

Fig. II - Site Plan




Fig. III – Aerial Photograph

4.0 Proposals

Fig. IV - Development Proposals




5.0 History of the Site

5.1 The first edition of 1:2500 maps (surveyed in 1884-92 and published in 1891-94, show an

area of farmland. For clarity, the approximate location of the proposed Industrial Unit is

shown in red.

Fig. V – c1891-94 Plan

6.0 Responsibilities of the Owner/Developer 6.1 Landowners have the primary responsibility for safeguarding their land and other property

against natural hazards such as flooding. Individual property owners and users are also

responsible for managing the drainage of their land in such a way as to prevent, as far as is

reasonably practicable, adverse impacts on neighbouring land.




6.2 Those proposing development are responsible for:-

o Demonstrating that it is consistent with Planning Policy.

o Providing a Flood Risk Assessment demonstrating:

i) Whether any proposed development is likely to be affected by current

or future flooding from any source;

ii) Satisfying the Local Planning Authority that the development is safe and

where possible reduces flood risk overall;

iii) Whether it will increase flood risk elsewhere and the measures proposed to

deal with these effects and risks.

iv) Any necessary flood risk management measures should be sufficiently

funded to ensure that the site can be developed and occupied safely

throughout its proposed lifetime.

o Designs which reduce flood risk to the development and elsewhere, by incorporating

sustainable drainage systems and, where necessary, flood resilience measures.

o Identifying opportunities to reduce flood risk, enhance biodiversity and amenity,

protect the historic environment and seek collective solutions to managing flood risk.

7.0 Site-specific Flood Risk Assessments

7.1 Planning applications for development proposals of one hectare or greater in Flood Zone 1

and all proposals for new development located in Flood Zones 2 and 3 should be accompanied

by a FRA. This should identify and assess the risks of all forms of flooding to and from the

development and demonstrate how these flood risks will be managed, taking climate change

into account.

7.2 For major developments in Flood Zone 1, the Flood Risk Assessment should identify

opportunities to reduce the probability and consequences of flooding.




7.3 A FRA will also be required where the proposed development or change of use to a more

vulnerable class may be subject to other sources of flooding or where the Environment Agency,

Internal Drainage Board and/or other bodies may indicate that there may be drainage

problems.

8.0 The Sequential Test 8.1 The risk-based Sequential Test should be applied at all stages of planning. Its aim is to steer

new development to areas at the lowest probability of flooding i.e. Zone 1

8.2 The Flood Zones are the starting point for the sequential approach. Zones 2 and 3 are shown

on the Environment Agency Flood Map with Flood Zone 1 being all the land falling outside

Zones 2 and 3.

8.3 These Flood Zones refer to the probability of sea and river flooding only, ignoring the presence

of existing defences.

8.4 Regional Flood Risk Appraisals (RFRAs) will refer to Environment Agency Flood Maps and

will utilise further information such as Strategic Flood Risk Assessments to allow flood risk to

be taken into account in a broad regional context

8.5 Strategic Flood Risk Assessments (SFRAs ) will refine information on the probability of

flooding, taking other sources of flooding and the impacts of climate change into account.

8.6 Where a SFRA is not available, the Sequential Test will be based on the Environment Agency

Flood Zones.

9.0 Test Results 9.1 No SFRA have been identified for this area.

9.2 Examination of The Environment Agency Flood Map reproduced below shows the area

where the industrial unit is proposed to have a very unlikely chance of flooding from rivers

and the sea.




Fig. VI - Extract from the Environment Agency’s Flood Map




9.3 Consulting Technical Guidance to the National Planning Policy Framework (March 2012)

and taking into account the Environment Agency’s Flood Maps Guidance Zone 1 – Low

Probability, the uses, requirements and aims in this zone are reproduced below

Table 1: Flood Zone

9.4 Table 2 below, also reproduced from the National Planning Policy Framework gives this site

a ‘Less Vulnerable’ flooding category as the site will be used for general industry.

.

Table 2: Flood Risk Vulnerability Classification




9.5 Table 3 below in the category ‘less vulnerable’ in and the flood risk Zone 1 concedes that

development is appropriate in this case, even without flood defences.

Table 3: Flood Risk Vulnerability and Flood Zone ‘Compatibility’

10.0 Assessment of the Flood risk

10.1 Flooding from rivers or streams

10.1.1 The Environment Agency Flood Maps have been consulted and they confirm that the site

falls within a Flood Zone 1 area indicating that flooding from rivers or streams is very

unlikely.

10.1.2 Application of the Sequential Test in NPPF concedes that development is appropriate, even

without flood defences.




10.1.3 A search has been made on the British Hydrological Society Chronology of British

Hydrological Events (http://www.dundee.ac/geography/cbhe) and an internet search but no

records were found of any flooding on the site.

10.1.4 Neither are there any past flood event locations recorded in Burnley on the Lancashire

Preliminary Flood Risk Assessment Map of Past Floods

Fig. VII - Extract from the Lancashire Flood Risk Assessment Map

10.2 Flooding from the Sea

10.2.1 The sea is some considerable distance away and has no influence on the site




10.3 Flooding from Land

10.3.1 As this site falls gently to the west there should be no flooding from the land

10.3.2 Rainfall falling on the site will follow the natural lie of the land and enter the existing

drainage system, which with regard to the existing buildings and vehicle and pedestrian areas

is retained in sub-surface porous material and is eventually returned to the drainage system

to the north west of the site.

10.3.3 The surface water for new buildings will need to be addressed by the provision of an

adequate SUDS drainage system to collect the rainwater and prevent it from causing a

problem to the development and other adjacent property.

Fig. VIII – Flow of Water Across the Site




10.4 Flooding from Groundwater

10.4.1 Groundwater flooding occurs when water levels in the ground rise above surface elevations.

10.4.2 No groundwater issues have been identified so flooding from this source is unlikely.

Fig. IX – Ground Water Flooding

10.5 Flooding from Sewers

10.5.1 Flooding of this site itself from public sewers is thought to be unlikely. However, the surface

water sewer which crosses the site to the north is overloaded downstream across the cricket

field so it is unlikely that United Utilities will allow a connection to it but there is already an

alternative to the north west after SUDS retention.

10.5.2 The proposals are to be designed so that there is no flooding to property with a 1:100 year

storm with a 20% increase for climatic change for a lifetime up to 2085 and 30% beyond this

date.




10.5.3 The existing surface water sewer will need to be diverted around the proposed building to the

north of the site

Fig. X – Sewer Map

10.6 Flooding from reservoirs, canals or other sources

11.6.1 The Leeds and Liverpool Canal lies to the south supported by an embankment

11.6.2 The site falls in the general direction of the blue arrows show in Fig. VIII and if there are any

problems the site is unlikely to be affected.




10.7 Flooding from Water Mains

10.7.1 If a water main bursts then the flows will be similar to overland flows from sewers and the

canal

10.7.2 It is also submitted that if the private and public water stop taps are accessible and suitable for

purpose, then it is not expected that there will be a problem.

Fig. XI – Water Mains




11.0 CONCLUSIONS

11.1 The area is in Zone 1 of the EA Flood Maps and has a ‘less vulnerable’ classification because

the site will be used for general industry. Application of the Sequential Test in accordance

with The Communities and Local Government Department: Technical Guidance to the

National Planning Policy Framework (March 2012) confirms that the site is considered to be

appropriate for development.

11.2 Although the flood risk to the development being low, it is advised that good quality seals to

all the access doors are fitted, the building ground floor level is as high as it can be and

electrical outlet sockets are 450mm above skirting level on the ground floor.

11.3 In this particular case it is not considered necessary to suggest that new occupiers take

advantage of the Environment Agency’s Flood Warning Scheme so that they may receive

information and decide upon the most suitable course of action should there be an extreme

rainfall event. Access to this service is via the internet.

11.4 Burnley Borough Council and United Utilities Sewer Management have no knowledge of

any flooding problems on this particular site although approval of an appropriate point of

connection and an approved SUDS design to ensure that the buildings to not flood in 1:100

year storm will no doubt be required.

11.5 It is concluded that there should be no significant risk of flooding to the inside of property or

car park and no predicable danger to life or property.

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Documents

2.0 Aims and Objectives - Borough of Burnley 0446 Flood... · 2013-12-03 · 2.0 Aims and Objectives 2.1 There are three aims and one objective of the report. The details of which