southampton coastal flood and erosion risk management strategy coastal... · southampton coastal...

Southampton

Coastal Flood and

Erosion Risk

Management

Strategy

Southampton

Coastal Flood and

Erosion Risk

Management

Strategy

Appendix 1G – Habitats Regulations Assessment Appendix 1G – Habitats Regulations Assessment

November 2012 November 2012

EC09/01/1673G EC09/01/1673G

Prepared for: Prepared for: Southampton City Council Southampton City Council

UNITED KINGDOM &

IRELAND

UNITED KINGDOM &

IRELAND

Southampton City Council — Southampton Coastal Flood and

Erosion Risk Management Strategy

APPENDIX 1G - HRA

November 2012

1

REVISION SCHEDULE

Rev Date Details Prepared by Reviewed by Approved by

0 05/10/2011 Consultation Draft ABPmer Dr John Pos

(Associate)

Dr James Riley

(Principal Ecologist)

David Dales

(Director – Water)

1 29/02/12 Revision and following new sea level rise guidance

Jonathan Short

(Coastal Engineer)

Dr James Riley


Dr John Pos

(Associate)

David Dales


2 25/05/2012 LPRG submission Jonathan Short

(Coastal Engineer)

Dr James Riley


Dr John Pos

(Associate)

David Dales


3 23/11/12 Final Jonathan Short

(Coastal Engineer)

Dr James Riley


Dr John Pos

(Associate)

David Dales


URS Scott House Alencon Link Basingstoke Hamsphire RG21 7PP



APPENDIX 1G - HRA

November 2012

2

Limitations

URS Infrastructure & Environment UK Limited (“URS”) has prepared this Report for the sole use of Southampton City Council (“Client”) in accordance with the Agreement under which our services were performed (EC09/01/1673 and 23 June 2010). No other warranty, expressed or implied, is made as to the professional advice included in this Report or any other services provided by URS. This Report is confidential and may not be disclosed by the Client nor relied upon by any other party without the prior and express written agreement of URS.

The conclusions and recommendations contained in this Report are based upon information provided by others and upon the assumption that all relevant information has been provided by those parties from whom it has been requested and that such information is accurate. Information obtained by URS has not been independently verified by URS, unless otherwise stated in the Report.

The methodology adopted and the sources of information used by URS in providing its services are outlined in this Report. The work described in this Report was undertaken between June 2010 and November 2012 and is based on the conditions encountered and the information available during the said period of time. The scope of this Report and the services are accordingly factually limited by these circumstances.

Where assessments of works or costs identified in this Report are made, such assessments are based upon the information available at the time and where appropriate are subject to further investigations or information which may become available.

URS disclaim any undertaking or obligation to advise any person of any change in any matter affecting the Report, which may come or be brought to URS’ attention after the date of the Report.

Certain statements made in the Report that are not historical facts may constitute estimates, projections or other forward-looking statements and even though they are based on reasonable assumptions as of the date of the Report, such forward-looking statements by their nature involve risks and uncertainties that could cause actual results to differ materially from the results predicted. URS specifically does not guarantee or warrant any estimate or projections contained in this Report.

Unless otherwise stated in this Report, the assessments made assume that the sites and facilities will continue to be used for their current purpose without significant changes.

Where field investigations are carried out, these have been restricted to a level of detail required to meet the stated objectives of the services. The results of any measurements taken may vary spatially or with time and further confirmatory measurements should be made after any significant delay in issuing this Report.

Costs may vary outside the ranges quoted. Whilst cost estimates are provided for individual issues in this Report these are based upon information at the time which can be incomplete. Cost estimates for such issues may therefore vary from those provided. Where costs are supplied, these estimates should be considered in aggregate only. No reliance should be made in relation to any division of aggregate costs, including in relation to any issue, site or other subdivision.

No allowance has been made for changes in prices or exchange rates or changes in any other conditions which may result in price fluctuations in the future.

Copyright

© This Report is the copyright of URS Infrastructure & Environment UK Limited. Any unauthorised reproduction or usage by any person other than the addressee is strictly prohibited.



APPENDIX 1G - HRA

November 2012

3

TABLE OF CONTENTS SUMMARY .............................................................................. 4ABBREVIATIONS ................................................................... 51 ................................................... 7INTRODUCTION

1.2 .............................. 12

Southampton Coastal Flood and Erosion Risk Management Strategy

2 ................................................ 13METHODOLOGY

2.1 ................. 15Screening and Scoping (Steps 1-6)

2.2 .............. 16Appropriate Assessment (Steps 8-9)

2.3 ....... 17Cumulative and In-Combination Impacts

3 ............................. 18SCREENING AND SCOPING

3.1

........................... 18

Steps 1 and 2: European Sites to be Considered, Including Interest Features and Conservation Objectives

3.2 ......... 29Assessment of Likely Significant Effect

4 .......... 37STEP 8: APPROPRIATE ASSESSMENT

4.2 ..................................... 39All ODUs: 2010 to 2060

4.3 ............ 39ODUs 1-7 (River Itchen): 2060 to 2110

4.4 ..................................................................... 40

ODUs 8-10 (Southampton Water): 2060 to 2110

4.5 .................. 40ODU 11 (Redbridge): 2060 to 2110

4.6 ................................................. 43Atlantic Salmon

4.7 ................................................................... 43Birds

4.8 ............................................ 43Overall Study Area

4.9 ....... 43Cumulative and In-Combination Impacts

4.10 .............................................. 45Step 9: Mitigation

5 .................................................... 46REFERENCES



APPENDIX 1G - HRA

November 2012

4

SUMMARY

ABP Marine Environmental Research Ltd (ABPmer) was commissioned by URS to undertake the Habitats Regulations Assessment for the Southampton Coastal Flood and Erosion Risk Management Strategy (The Strategy). The Habitats Regulations Assessment has since been amended and revised by URS following the issue of updated sea level rise guidance (EA 2011) prior to the final Strategy release.

The Strategy has identified a series of preferred options for 11 Option Development Units along the Southampton frontage over the next 100 years. A Habitats Regulations Assessment (HRA) is required for The Strategy preferred options to identify any potential likely significant effect (LSE) on sites designated for their nature conservation interest under the Birds and Habitats Directives (Natura 2000 sites). This Strategy HRA has been undertaken within the context and taking account of the conclusions of the North Solent SMP HRA. Coastal squeeze is considered the principle impact pathway of The Strategy having the potential to affect designated intertidal habitats as well as bird species and salmon supported by these habitats. It is concluded that The Strategy preferred options will have no adverse effect on intertidal habitats and associated species, over and above those already identified and accounted for within the SMP, except for a potential local adverse effect on intertidal area at Redbridge beyond 2060. Project level HRAs will need to be completed where necessary to ensure no LSE for individual schemes.



APPENDIX 1G - HRA

November 2012

5

ABBREVIATIONS

AA Appropriate Assessment

ABP Associated British Ports

ABPmer ABP Marine Environmental Research Ltd

ATL Advance the Line

CDS Coastal Defence Strategy

CHaMP Coastal Habitat and Management Plan

cSAC candidate SAC

DC District Council

EC European Commission

HRA Habitats Regulations Assessment

HRG Habitat Regulations Guidance

HTL Hold the Line

IROPI Imperative Reasons of Overriding Public Interest

LSE Likely significant effect

MR Managed realignment

NAI No active intervention

ODU Option development unit

pSPA potential SPA

Ramsar sites Wetland sites of international importance designated under the Ramsar Convention

RHCP Regional Habitat Creation Programme

SAC Special Area of Conservation

SCI Site of Community Importance

SL Secondary Line

SMP Shoreline Management Plan

SPA Special Protection Area

mm Millimetre

km Kilometre



APPENDIX 1G - HRA

November 2012

6

ha Hectare

% Percentage

ODN Ordnance Data Newlyn

UK United Kingdom



APPENDIX 1G - HRA

November 2012

7

1 INTRODUCTION

ABP Marine Environmental Research Ltd (ABPmer) was commissioned by URS to undertake the Habitats Regulations Assessment for the Southampton Coastal Flood and Erosion Risk Management Strategy (from hereon referred to as ‘The Strategy’). The Habitats Regulations Assessment has since been amended and revised by URS following the issue of updated sea level rise guidance (EA 2011) prior to the final Strategy release.

1.1.1 Structure of Report

This report will follow the structure below to complete the HRA process:

Introduction;

Methodology;

Screening and scoping;

Appropriate Assessment.

1.1.2 Background

The Strategy area covers a 22km long stretch of the City of Southampton from Redbridge, following the eastern bank of the River Test, south of the M27, along the frontage of Southampton Water and following the western bank of the River Itchen north to Woodmill. The study area is divided into eleven Option Development Units (ODU) which are listed below in Table 1 and displayed in Figure 1.

Table 1. Option development units within the Southampton Coastal Defence Strategy

Option Development Unit Area

1 Upper Itchen / St Denys

2 Bevois Valley

3 Meridian Studios

4 Northam

5 St Mary’s Wharves

6 Crosshouse / Town Depot

7 Ocean Village

8 Dock Gate 4 / Eastern Docks

9 Mayflower Park / Major Development Quarter

10 Western Docks

11 Redbridge

S

outh

ampt

on C

ity C

ounc

il

Sou

tham

pton

Coa

stal

Flo

od a

nd E

rosi

on R

isk

Man

agem

ent S

trat

egy

AP

PE

ND

IX 1

G –

HR

A

Nov

embe

r 20

12

8

F

igu

re 1

. Str

ateg

y P

refe

rred

op

tio

ns

and

Op

tio

n D

evel

op

men

t U

nit

s.



APPENDIX 1G - HRA

November 2012

9

Land use within the study area is mainly urban with a mixture of docks, industrial, commercial and residential development, as well as areas of natural and historical significance. Areas of reclaimed land form the Port of Southampton and much of the frontage is dominated by marine and coastal industries such as marinas, boat yards and wharfs requiring access to the sea.

The tidal floodplain (defined by the Environment Agency Flood Zones and tidal modelling undertaken in this study) is relatively extensive due to the topography, and includes port assets, waterside development, transport network, sewage works, and other associated infrastructure as well as residential property. There are listed and historic buildings and monuments, registered parks (English Heritage) and gardens, and conservation areas within the floodplain.

Within the River Itchen and the wider Southampton Water and Solent areas there are intertidal habitats, as well as bird and fish interests, of international, European and national nature conservation importance. Therefore the potential implications of The Strategy need to be formally reviewed within a Habitat Regulations Assessment (HRA).

1.1.3 Coastal Management Options

There are no formal raised flood defences within the City of Southampton; however, a large proportion of Southampton frontage is covered by quay areas that form part of the Port of Southampton. These offer protection from flooding, although they are not considered formal flood defences.

The Strategy has been developed following the acceptance of the North Solent Shoreline Management Plan (SMP). The Strategy and SMP policies for the study area are provided in Table 2 below.

Within The Strategy preferred options have been identified for each ODU and means of delivery. Preferred options have been selected for the short term (0-20 years), medium term (20-50 years) and long term (50-100 years) for each ODU. For consistency between each ODU preferred options have been provided for years 2030, 2060 and 2110. The preferred options for each time period in each ODU are listed below in Table 2.

ODUs 1 to 10 comply with the SMP policy of Hold the Line (HTL). For ODUs 7 to 10 positive defence lines are set back behind the port. It is assumed that the port infrastructure would be maintained during the life of The Strategy and therefore The Strategy also follows the SMP for these ODUs with respect to the remit of the HRA. ODU 11, Redbridge, lies within the much larger SMP unit of 5c13 which has a policy of No Active Intervention (NAI).

S

outh

ampt

on C

ity C

ounc

il

Sou

tham

pton

Coa

stal

Flo

od a

nd E

rosi

on R

isk

Man

agem

ent S

trat

egy

AP

PE

ND

IX 1

G -

HR

A

Nov

embe

r 20

12

10

Tab

le 2

. Pre

ferr

ed o

pti

on

fo

r ea

ch o

pti

on

dev

elo

pm

ent

un

it

Are

a U

pp

er I

tch

en

/ S

t D

enys

B

evo

is V

alle

yM

erid

ian

S

tud

ios

No

rth

am

St

Mar

y’s

Wh

arve

s C

ross

ho

us

e /

To

wn

Dep

ot

Oce

an

Vill

age

Eas

tern

D

ock

s /

Do

ck

Gat

e 4

Ma

yflo

wer

P

ark

/ Maj

or

De

velo

pm

en

t Q

uar

ter

Wes

tern

D

ock

s R

edb

rid

ge

Op

tio

n

De

velo

pm

en

t U

nit

1

2 3

4 5

6 7

8 9

10

11

Pre

ferr

ed

op

tio

n

2015

to 2

060

C

omm

unity

an

d pr

ope

rty

leve

l flo

od

resi

stan

ce a

nd

resi

lienc

e 20

60 to

211

0

Flo

od w

all

near

the

fron

t lin

e

2015

to 2

030

M

aint

ain

exis

ting

defe

nce

stru

ctur

es

2030

to 2

110

–S

teel

she

et

pile

wal

l at t

he

fron

t lin

e

2015

to 2

060

In

term

edia

te

heig

ht

flood

wal

l fo

rmin

g th

e sp

ine

of

defe

nce

until

ra

ised

land

su

pers

edes

th

e w

all a

s th

e m

ain

defe

nce

by

2060

. 20

60 to

211

0

Def

ende

d b

y a

cont

inuo

us

strip

of r

aise

d la

nd.

2015

to 2

060

In

term

edia

te

heig

ht

flood

wal

l fo

rmin

g th

e sp

ine

of

defe

nce

until

ra

ised

land

su

pers

edes

th

e flo

odw

all

as th

e m

ain

defe

nce

by

2060

. 20

60 to

211

0

Def

ende

d b

y a

cont

inuo

us

strip

of r

aise

d la

nd.

2015

to 2

060

In

term

edia

te

heig

ht

flood

wal

l fo

rmin

g th

e sp

ine

of

defe

nce

until

ra

ised

land

su

pers

edes

th

e flo

odw

all

as th

e m

ain

defe

nce

by

2060

. 20

60 to

211

0

Def

ende

d b

y a

cont

inuo

us

strip

of r

aise

d la

nd.

2015

to 2

110

D

efen

ded

by

rais

ed la

nd

impl

emen

ted

thro

ugh

rede

velo

pmen

t

2015

to 2

060

M

aint

ain

exis

ting

qua

y w

alls

and

de

fenc

e st

ruct

ures

20

60 to

211

0

Def

ende

d b

y ra

ised

qua

y w

alls

with

flo

odw

all

defe

nces

al

ong

perim

eter

of

AB

P la

nd.

2015

to 2

060

D

o no

thin

g.

The

are

a be

hind

Por

t pr

otec

ted

agai

nst

flood

ing

by

the

exis

ting

qua

y w

alls

in th

e P

ort a

nd T

he

Str

ateg

y de

fenc

es

alon

g th

e Itc

hen

fron

tage

to

the

nort

h.

2060

to 2

110

D

efen

ded

by

a flo

odw

all

arou

nd O

cean

V

illag

e an

d al

ong

the

boun

dary

of

the

Por

t.

2015

to 2

060

La

nd r

aisi

ng

thro

ugh

deve

lopm

ent

of R

oya

l Pie

r S

ite a

nd th

e M

ajor

D

evel

opm

ent

Qua

rter

pr

efer

red.

Im

plem

enta

tion

of a

floo

dw

all

form

ing

the

spin

e of

the

flood

def

ence

b

y 20

30 if

a

cont

inuo

us

strip

of r

aise

d la

nd is

not

ac

hiev

ed b

y th

is ti

me.

20

60 to

211

0

Def

ende

d b

y a

flood

wal

l and

/ or

rai

sed

land

.

2015

to 2

060

D

o no

thin

g.

The

are

a be

hind

Por

t pr

otec

ted

agai

nst

flood

ing

by

the

exis

ting

qua

y w

alls

in th

e P

ort.

2060

to 2

110

–A

rea

behi

nd

the

Por

t de

fend

ed

agai

nst

flood

ing

by

a flo

odw

all a

long

th

e bo

unda

ry

of th

e P

ort

ram

ps /

dem

ount

able

s on

acc

ess

poin

ts.

2015

to 2

030

D

efen

ded

by

exis

ting

stru

ctur

es a

nd

land

leve

ls

2030

to 2

060

C

omm

unity

an

d pr

ope

rty

leve

l flo

od

resi

stan

ce a

nd

resi

lien

ce

2060

to 2

110

F

lood

wal

l al

ong

the

seaw

ard

sid

e of

the

railw

ay

emba

nkm

ent.



APPENDIX 1G - HRA

November 2012

11

The SMP has itself been subject to a HRA and this Strategy HRA has been undertaken within the context and taking account of its conclusions. The SMP assessment concluded that the SMP will have an adverse impact on the following designated sites: Solent and Southampton Water SPA and Ramsar, Portsmouth Harbour SPA and Ramsar, Chichester and Langstone Harbours SPA and Ramsar and the Solent Maritime SAC. Subject to approval to Imperative Reasons of Overriding Public Interest (IROPI) the North Solent SMP needs to secure compensation to maintain the integrity of the Natura 2000 network. These compensation requirements will form part of the Southern Regional Habitat Creation Programme (RHCP). In particular there is the opportunity for intertidal habitat creation as a result of managed realignment policies at Medmerry, East Chidham and Chidham. These sites can provide compensation for losses to intertidal habitats due to coastal squeeze as a result of HTL policies elsewhere within the plan area. Medmerry, in particular, provides compensation for a significant proportion of intertidal habitat, through the creation of 122ha of saltmarsh and 99ha of mudflat, as well as providing a new and sustainable estuary with its own ecological and physiological characteristics to support Ramsar and SPA bird interests. This Strategy HRA assumes these adverse impacts are fully addressed.

1.1.4 Legislative Context

Under the Council Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild Fauna and Flora (the Habitats Directive) it is necessary to undertake a HRA of a plan or project to determine whether it will have a “likely significant effect” (LSE) on sites designated for their nature conservation interest at an international level. This Directive has been transposed into national laws through the Conservation of Habitats and Species Regulations 2010 (Habitats Regulations 2010). In particular Regulation 61 states that

“A competent authority, before deciding to undertake, or give any consent, permission, or other authorisation for a plan or project which:

(a) is likely to have significant effect on a European site in Great Britain (either alone or in combination with other plans or projects); and

(b) is not directly connected or necessary to the management of the site shall make an appropriate assessment of the implications for the site in view of that site’s conservation objectives”.

European site (also referred to as a Natura 2000 site) is either a Special Area of Conservation (SAC) identified through the EU Habitats Directive (Council Directive 92/43/EEC) or Special Protection Area (SPA) identified through the Birds Directive (Council Directive 79/409/EEC). Additionally, it is a matter of policy throughout the UK that Ramsar sites identified through the Ramsar Convention 1976 should receive the same protection as designated SPAs and SACs. Therefore, Ramsar sites are included under the European Site heading for the purposes of carrying out an Appropriate Assessment, even though they are not technically classed as European sites.

In the UK, it is also Government policy (as indicated in the following documents: Scottish Government (SG), 2010; Office of Deputy Prime Minister (ODPM), 2005; Welsh Assembly Government (WAG), 2010; Department of Environment for Northern Ireland (DOENI), 1997), that these requirements are also extended to the consideration of effects on sites that are proposed for designation such as potential SPAs (pSPAs) and



APPENDIX 1G - HRA

November 2012

12

candidate SACs (cSACs), and this would also include any proposed extensions or additions to existing Natura 2000 sites.

When evaluating the effects on designated sites as part of the HRA process, if the relevant Competent Authority, cannot conclude that the plan or project will not have an adverse effect on the integrity of a European site (either alone or in combination with other plans or projects) the plan can only be adopted if it has been ascertained that there are no alternative solutions and it is necessary for Imperative Reasons for Overriding Public Interest (IROPI), including those of a social or economic nature1. In such cases, compensatory measures must be taken to ensure that the overall coherence of the network of Natura 2000 sites is maintained.

1.2 Southampton Coastal Flood and Erosion Risk Management Strategy

Given the proximity of The Strategy frontage to internationally designated sites (see Section 3.1, Figure 3) the possibility of ‘likely significant effects’ (LSE) on European designated sites cannot be excluded and therefore an HRA is required. In the case of this HRA Southampton City Council is the competent authority. Southampton City Council, with advice from Natural England, will need to ensure that if there is a negative assessment of a plan or project, agreement to that plan or project is only given if there are no alternative solutions, it must be carried out for Imperative Reasons of Overriding Public Interest (IROPI), and any compensatory measures that may be required are secured.

1 Article 6 of the Habitats Directive also states that, where the site concerned hosts a priority natural habitat, type

and/or a priority species, the only considerations which may be raised are those relating to human health or public safety, to beneficial consequences of primary importance for the environment or, further to an opinion from the Commission, to other imperative reasons of overriding public interest.



APPENDIX 1G - HRA

November 2012

13

2 METHODOLOGY

The following section sets out the overarching methodology for carrying out an HRA. This methodology is applied specifically to the assessment of The Strategy in Sections 3 and 4.

For this HRA, an iterative and auditable process has been followed to ensure that there is as much clarity as possible in the process and also to ensure that the relevant documentation can be readily accessed, interpreted and interrogated. In particular, the information and detail provided in this report is based on recommendations within the relevant Habitats Regulations Guidance (HRGN1) on Appropriate Assessment methods (English Nature, 1997) and agreed guidance for undertaking HRAs for plans in England which has been produced by David Tyldesley and Associates (2010). This diagram was presented in the Habitats Regulations Assessment Record, but has been adapted in this document to inform the reader of the process relating specifically to The Strategy HRA. This guidance document sets out the stages to be pursued in a flow diagram format (Figure 2).



APPENDIX 1G - HRA

November 2012

14

Figure 2. Overview Guidance for Undertaking HRAs for Plans in England



APPENDIX 1G - HRA

November 2012

15

In outline the HRA for The Strategy covers these 13 stages in the following iterative steps:

Steps 1 and 2: Section 4.1 identifies European sites within 5km of The Strategy area and identifies the interest features and conservation objectives that may potentially be affected;

Step 3: Section 4.2.1 identifies potential impact pathways that could arise as a result of The Strategy;

Step 4, 5 and 6: Section 4.2.2 identifies potential impacts and the likely significant effect of interest features of designated sites;

Step 7: responsibility of Southampton City Council;

Step 8 and 9: Section 4, the AA assesses the impacts of identified pathways on the remaining screened in features, identifying potential adverse affects on the integrity of European sites, including cumulative and in-combination impacts and appropriate mitigation;

Steps 10 to 13: responsibility of Southampton City Council.

Further details on the overarching methodology used to complete these steps within this HRA are provided below in Sections 4.1 to 4.3. Throughout this HRA an assessment has been made in relation to each of the respective ODU preferred options and their impacts on the integrity of European Designated sites.

With respect to the project-level responsibilities of implementing the policies, it is important to note that this Plan-level HRA does not preclude the need for HRAs at a project level and, indeed, it will remain a legal requirement for projects undertaken as part of this Plan to also undergo a project-level Appropriate Assessment wherever the possibility of a LSE on a European site cannot be excluded. It is recognised however that the high-level plan assessment can provide valuable information for project-level HRAs.

Consultation with respect to all aspects of this HRA will be undertaken by Southampton City Council, as the competent authority.

2.1 Screening and Scoping (Steps 1-6)

This stage in the methodology involves analysing the Conservation Objectives for each of the relevant European sites identified. For some sites generic conservation objectives may need to be used. Based on these specific and generic objectives, the potential effects on each site via each of the impact pathways will be reviewed and an initial view taken about the effect on site integrity of the proposed plan both alone and in-combination with other extant plans or projects. The views expressed about the effects on site integrity will be based on: current scientific understanding; the proposed manner in which the plan is to be implemented and any proposals for mitigation measures to avoid or reduce impacts.

The next stage involves selecting the final list of the sites and interest features which are to be ‘screened into’ the AA either because there is a ‘Likely Significant Effect’ (or LSE) or because a LSE cannot be excluded via the identified impact pathways. The



APPENDIX 1G - HRA

November 2012

16

impact pathways are listed in Section 3.2.1. Therefore, this screening stage of the process determines which of these impact pathways needs to be taken into the assessment process because they represent a LSE.

It should be noted that LSE is not defined in the Habitats Regulations. LSE is recognised within Natural England as being a ‘coarse filter’ or statement that the anticipated effects of the proposal will be more than trivial, i.e. that the anticipated change(s) resulting from the proposal has the potential to impact on a receptor designated as a feature of the European Site. It does not automatically follow that an impact will occur, or that the impact would be significant, with a decision of LSE being purely an indication of the need for an Appropriate Assessment.

Given the need for a high level of certainty to meet Habitats Regulations requirements, there is a presumption in favour of ‘screening issues in’ at this stage, following the precautionary approach. This will be important also for undertaking any detailed assessments (at this Plan-level or in future Project-level assessment work) where there needs to be sufficient confidence in the evidence base and that the delivery of projects under the plan can be sufficiently controlled to avoid adverse effect on integrity. When considering the relevant screening methods to determine LSE, it is therefore understood that there again needs to be a presumption in favour of including rather than excluding interest features and designated sites in the HRA process at this stage.

Furthermore a potential impact pathway as a result of the proposed scheme will only be an issue to interest features that form part of the marine and coastal environment in the study area. In other words, there is no route of interaction for terrestrial and/or freshwater organisms and habitats, excluding those that are able to use different environments, such as migratory Atlantic salmon moving between the open sea and rivers (mainly the chalk rivers of the Test and Itchen). Furthermore, an impact pathway will only exist at locations where a direct and/or indirect impact will occur as a result of the preferred options.

In compiling information on the designated sites, the starting point has been Natural England’s advice given under Regulation 33(2) (now Regulation 35) of the Habitat Regulations for the Solent European Marine Site (English Nature, 2001). It has also taken into consideration Natura 2000 standard data forms and Information sheets on Ramsar Wetlands (Joint Nature Conservation Committee website; http://www.jncc.gov.uk). Detailed descriptions of European Sites are presented in Section 3.1.

2.2 Appropriate Assessment (Steps 8-9)

The main objective of the Appropriate Assessment is to ascertain that The Strategy will not have an adverse effect on the integrity of the European Sites and, where adverse affects do arise from the plan, to quantify these effects and recommend mitigation measures to offset these impacts on the site. An adverse effect of The Strategy is one which prevents the European Site from reaching or maintaining its targets for the site’s conservation objectives. The effects of The Strategy on European sites affected are shown in Table 9, Section 3.2.2.

The precautionary approach is also enshrined in the Appropriate Assessment. In particular, under the Habitats Regulations, there is a need for a high level of certainty in

http://www.jncc.gov.uk/



APPENDIX 1G - HRA

November 2012

17

the assessment conclusions (also following the precautionary principle). This is also highlighted within the Waddenzee judgement which concluded that ‘a plan or project [that is] likely to have significant effect on the site is only to be authorised if it is ascertained that it will not adversely affect the integrity of the site (i.e. where no reasonable scientific doubt remains as to the absence of such effects).

2.3 Cumulative and In-Combination Impacts

The AA will identify the potential cumulative and in-combination effects associated with plan implementation, flag up particular risks and document how these issues should be taken forward through project level HRA. In particular, given the uncertainties that exist about how and when the preferred options will be implemented, it must be recognised that there are significant difficulties in undertaking detailed in-combination assessments. The approach adopted in previous strategic HRAs is to recognise these limitations and this approach is advocated here. These past assessments have sought to identify the potential for in-combination issues to arise from multiple developments within the plan and also to identify the range of other plans and projects that might potentially interact with the plan being assessed, with more detailed assessment being remitted to project level, see Section 4.2.

The following sections apply the overarching methodology described above to The Strategy specifically.



APPENDIX 1G - HRA

November 2012

18

3 SCREENING AND SCOPING

3.1 Steps 1 and 2: European Sites to be Considered, Including Interest Features and

Conservation Objectives

The Strategy area lies within Southampton Water from Redbridge on the River Test around the main part of the City to Woodmill at the tidal extent of the River Itchen. The international nature conservation importance of the area has been recognised through a number of statutory designations. All internationally designated sites greater than 5km from The Strategy have been screened out of the assessment. Internationally designated sites within 5km of the proposed plans include:

Special Protected Areas (SPA) designated under the Birds Directive (Council Directive 79/409/EEC):

New Forest SPA;

Solent and Southampton Water SPA.

Wetlands of International importance designated under the Ramsar Convention:

New Forest Ramsar site;

Solent and Southampton Water Ramsar site.

Special Areas of Conservation (SAC) designated under the EU Habitats Directive (Council Directive 92/43/EEC):

New Forest SAC;

River Itchen SAC;

Solent Maritime SAC.

The Solent and Southampton Water SPA and Ramsar site and the Solent Maritime SAC form part of the Solent European Marine Site as defined in the Habitats Regulations. Where the European Site lies below highest astronomical tide i.e. land covered (continuously or intermittently) by tidal waters, or any part of the sea, in or adjacent to Great Britain, up to the seaward limit of territorial waters, it is described as a European Marine Site.

The boundaries of these designated sites in relation to The Strategy are shown in Figure 3. Further information on the qualifying and interest features, conservation objectives and vulnerabilities for the designated sites that will be covered by the assessment are given in the following sections.

A tabulated summary of the interest features and conservation objective habitats is presented in Table 6.

S

outh

ampt

on C

ity C

ounc

il

Sou

tham

pton

Coa

stal

Flo

od a

nd E

rosi

on R

isk

Man

agem

ent S

trat

egy

AP

PE

ND

IX 1

G -

HR

A

Nov

embe

r 20

12

19

Fig

ure

3. E

nvi

ron

men

tal D

esig

nat

ion

s ar

ou

nd

th

e S

ou

tham

pto

n s

tud

y fr

on

tag

e.



APPENDIX 1G - HRA

November 2012

20

3.1.1 Special Protection Areas (SPA)

The EC Birds Directive (79/409/EEC) requires all member states to identify areas to be given special protection for the rare or vulnerable waterbird species listed in Annex 1 (Article 4.1) and for regularly occurring migratory species (Article 4.2) and for the protection of wetlands, especially wetlands of international importance.

New Forest SPA

The New Forest SPA, covering 28003ha, was designated in September 1993. The SPA comprises 29% broad-leaved deciduous woodland, 27% heath and scrub, 18% dry grassland and steppes, 17% coniferous woodland, 6% bog, marsh, water fringed vegetation and fens, 2% humid grassland and less than 1% inland water bodies. The boundary of the New Forest SPA site in relation to the study area is shown in Figure 3.

The New Forest SPA achieves the following:

Article 4.1 – regularly supports an internationally important population of breeding Annex I species, comprising Nightjar, Woodlark, Honey Buzzard and Dartford Warbler, and overwintering Annex I species, Hen Harrier; and

Article 4.2 – during the breeding season supports internationally important populations of Eurasian Hobby and Wood Warbler.

As the New Forest SPA does not form part of a European Marine Site, there is no Natural England advice under Regulation 33 of the favourable condition targets for qualifying features. However it can be assumed that conservation objectives for the site would be to maintain habitats which support internationally important bird species in a favourable condition, subject to natural change.

The site is considered to be sensitive to recreational pressures and disturbance. Low water levels may also affect the wetland habitats which are sensitive to drainage pressures and erosion.

Solent and Southampton Water SPA

The Solent and Southampton Water SPA, covering 5506ha, was designated in October 1998. The SPA comprises 48% tidal rivers, estuaries, mudflats, sandflats and lagoons (including saltwork basins), 18% saltmarshes, salt pastures and salt steppes, 17% humid and mesophile grassland, 10% shingle, sea cliffs and islets, 3% bog, marsh, water fringed vegetation and fens, 3% coastal sand dunes, sand beaches and machair, and 1% broad-leaved deciduous woodland. The boundary of the Solent and Southampton Water SPA site in the study area is shown in Figure 3.

The Solent and Southampton SPA achieves the following:

Article 4.1 – regularly supports an internationally important population of breeding Annex I species, comprising Mediterranean Gull, Little Tern, Roseate Tern, Common Tern, Sandwich Tern; and

Article 4.2 – supports an internationally important assemblage of birds over winter (51361 waterfowl), and internationally important populations of regularly occurring migratory species, including Eurasian Teal, Dark-bellied Brent Goose, Ringed Plover, and Black-tailed Godwit.



APPENDIX 1G - HRA

November 2012

21

The conservation objectives of the Solent and Southampton Water SPA as defined in the Regulation 33 advice for the Solent EMS are shown in Table 3 below.

The site is considered to be particularly sensitive to activities or developments which result in loss of habitat through direct removal or coastal squeeze, modification of physical processes and sediment transfer patterns, pollution, and disturbance.

Table 3. Conservation objectives for Solent and Southampton Water SPA


Internationally important populations of regularly occurring Annex I species

Subject to natural change, maintain in favourable condition the habitats for the internationally important populations of the regularly occurring Annex 1 species, in particular sand and shingle, saltmarsh, intertidal mudflats and sandflats and shallow coastal waters.

Internationally important regularly occurring migratory species

Subject to natural change, maintain in favourable condition the habitats for the internationally important populations of the regularly occurring migratory species, in particular, saltmarsh, intertidal mudflats and sandflats, boulder and cobble shores and mixed sediment shores.

Internationally important waterfowl assemblage

Subject to natural change, maintain in favourable condition the habitats for the internationally important assemblage of waterfowl, in particular saltmarsh, intertidal mudflats and sandflats, boulder and cobble shores and mixed sediment shores.

3.1.2 Ramsar Sites

Under the 1972 Ramsar Convention on Wetlands of International Importance, it is a requirement of signatory states to protect wetland sites of international importance, including those that are important waterfowl habitats.

New Forest Ramsar

The New Forest Ramsar Site was designated in September 1993 and overlaps entirely with the New Forest SPA, covering 28,003ha. The New Forest is an area of semi-natural vegetation including valley mires, fens and wet heath. Other wetland habitats include numerous ponds and a network of small streams mainly acidic in character, which have no lowland equivalent in the UK. The habitats present are of high ecological quality and diversity with undisturbed transition zones. The boundary of the New Forest Ramsar site in the study area is shown in Figure 3.

The New Forest was designated a Ramsar site by meeting the qualifying criteria outlined below:

Criterion 1 – Valley mires and wet heaths are found throughout the site and are of outstanding scientific interest. The mires and heaths are within catchments whose uncultivated and undeveloped state buffers the mires against adverse ecological change. This is the largest concentration of intact valley mires of their type in Britain;

Criterion 2 – The site supports a diverse assemblage of wetland plants and animals including several nationally rare species. Seven species of nationally rare plant are found on the site, as are at least 65 British Red Data Book species of invertebrate;

Criterion 3 – The mire habitats are of high ecological quality and diversity and have undisturbed transition zones. The invertebrate fauna of the site is important due to the concentration of rare and scarce wetland species. The whole site complex, with



APPENDIX 1G - HRA

November 2012

22

its examples of semi-natural habitats is essential to the genetic and ecological diversity of southern England.

Noteworthy fauna within the New Forest Ramsar site include nationally important breeding populations of the Dartford Warbler, Sylvia undata and Hen Harrier, Circus cyaneus as well as internationally and nationally important invertebrate species.

As the New Forest Ramsar site does not form part of a European Marine Site, there is no Natural England advice under Regulation 33(2) of the favourable condition targets for qualifying features. However it can be assumed that conservation objectives for the site would be to maintain wetland habitats in a favourable condition, subject to natural change.

The site is considered to be sensitive to recreational pressures and disturbance. Low water levels may also affect the wetland habitats which are sensitive to drainage pressures and erosion.

Solent and Southampton Water Ramsar

The Solent and Southampton Water Ramsar Site was designated in October 1998 and overlaps entirely with the Solent and Southampton Water SPA, covering 5346ha. The site comprises estuaries and adjacent coastal habitats, including intertidal flats, saline lagoons, shingle beaches, saltmarsh, reedbeds, damp woodland, and grazing marsh. The different habitats support internationally important numbers of wintering waterfowl, important breeding gull and tern populations and an important assemblage of rare invertebrates and plants. The boundary of the Solent and Southampton Water Ramsar site in the study area is shown in Figure 3.

The Solent and Southampton Water was designated a Ramsar site by meeting the qualifying criteria outlined below:

Criterion 1 – The site is one of the few major sheltered channels between a substantial island and mainland in European waters, exhibiting an unusual strong double tidal flow with long periods of slack water at high and low tide. It comprises many wetland habitats characteristic of the biogeographic region: saline lagoons, saltmarshes, estuaries, intertidal flats, shallow coastal waters, grazing marshes, reedbeds, coastal woodland and rocky boulder reefs;

Criterion 2 – The site supports an important assemblage of rare plants and invertebrates. At least 33 British Red Data Book invertebrates and at least eight British Red Data Book plants are represented on site;

Criterion 5 – supports internationally important assemblages of overwintering waterfowl (51343 waterfowl); and

Criterion 6 – used regularly by species/populations occurring at levels of international importance. Qualifying species/populations (as identified at designation) that have peak counts in spring/autumn are Ringed Plover. Those having peak counts in winter are Dark-bellied Brent Goose, Eurasian Teal and Black-tailed Godwit.

The conservation objectives of the Solent and Southampton Water Ramsar site as defined in the Regulation 33 advice for the Solent EMS are listed in Table 4 below.

Table 4. Conservation objectives for Solent and Southampton Water Ramsar Site.



APPENDIX 1G - HRA

November 2012

23


Atlantic biogeographical region

Subject to natural change, maintain the internationally important wetland characteristic of the Atlantic biogeographical region in favourable condition, in particular, estuaries, saline lagoons, saltmarsh and intertidal reefs.

Assemblage of rare, vulnerable or endangered species

Subject to natural change, maintain the wetland hosting an assemblage of rare, vulnerable or endangered species in favourable condition, in particular, saline lagoons, saltmarsh, cordgrass swards (Spartinon spp.).

20,000 waterfowl species Subject to natural change, maintain the wetland regularly supporting 20,000 waterfowl species in favourable condition, in particular, saltmarshes, intertidal mudflats and sandflats, boulder and cobble shores, and mixed sediment shores.

1% or more of the individuals in a population of waterfowl species

Subject to natural change, maintain the wetland regularly supporting 1% or more of the individuals in a population of waterfowl species in favourable condition, in particular, saltmarshes, sand and shingle, shallow coastal waters, intertidal mudflats and sandflats, and boulder and cobble shores, and mixed sediment shores.

The site is considered to be particularly sensitive to activities or developments which result in loss of habitat through direct removal or coastal squeeze, modification of physical processes and sediment transfer patterns, pollution, and disturbance.

3.1.3 Special Areas of Conservation (SAC)

The EC Habitats Directive (92/43/EEC) requires the establishment of a European network of important high-quality conservation sites that will make a significant contribution to conserving the 189 habitat types and 788 species identified in Annexes I and II of the Directive (as amended).

New Forest SAC

The New Forest was proposed as eligible as a Site of Community Importance (SCI) in June 1995 and designated as SAC in April 2005. The SAC covers 29262ha and comprises 34% heath, scrub, maquis, garrigue and phygrana, 29% broad-leaved deciduous woodland, 17% coniferous woodland, 10% dry grassland and steppes, 7% bog, marsh, water fringed vegetation and fen, and 3% humid grassland and mesophile grassland. The boundary of the New Forest SAC site in the study area is shown in Figure 3.

Annex I habitats that are a primary reason for selection of this site are:

Oligotrophic waters containing very few minerals of sandy plains, Littorelletalia uniflorae;

Oligotrophic to mesotrophic standing waters with vegetation of the Littorelletea uniflorae and/or of the Isoeto-Nanojuncetea;

Northern Atlantic wet heaths with Erica tetralix;

European dry heaths;

Molinia meadows on calcareous, peaty or clayey-silt-laden soils;



APPENDIX 1G - HRA

November 2012

24

Depressions on peat substrates of the Rhynchosporion;

Atlantic acidophilous beech forests with Ilex and sometimes also Taxus in the shrublayer (Quercion robori-petraeae or Ilici-Fagenion);

Asperulo-Fagetum beech forests;

Old acidophilous oak woods with Quercus robur on sandy plains;

Bog woodland; and

Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-Padion, Alnion incanae, Salicion albae).

Annex I habitats that are a qualifying feature for site selection are:

Transition mire and quaking bog; and

Alkaline fen.

Annex II species that are a primary reason for selection of this site are:

Southern damselfly, Coenagrion mercuriale; and

Stag beetle, Lucanus cervus.

Annex II species that are a qualifying feature for site selection are:

Great crested newt, Triturus cristatus.

As the New Forest SAC does not form part of a European Marine Site, there is no Natural England advice under Regulation 33(2) of the favourable condition targets for qualifying features. However it can be assumed that conservation objectives for the site would be to maintain Annex I habitats for which the site has been designated in a favourable condition, subject to natural change.

The site is considered to be sensitive to the drainage of wetland habitats, afforestation of heathlands, grazing and recreational pressures.

Solent Maritime SAC

The Solent Maritime SAC, covering 11,325ha, was proposed as eligible as a Site of Community Importance (SCI) in October 1998, and designated as SAC in April 2005. The SAC comprises 59% tidal rivers, estuaries, mudflats, sandflats and lagoons (including saltwork basins), 23% salt marshes, salt pastures and salt steppes, 14% marine areas and sea inlets, 3% shingle, sea cliffs and islets, and 1% coastal sand dunes, sand beaches, machair, and broad-leaved deciduous woodland. The boundary of the Solent Maritime SAC site in the study area is shown in Figure 3.


Estuaries;

Spartina swards (Spartinion maritimae); and



APPENDIX 1G - HRA

November 2012

25

Atlantic salt meadows (Glauco-Puccinellietalia maritimae).

Annex I habitats present as a qualifying feature for selection of this site are:

Sandbanks which are slightly covered by seawater all the time;

Mudflats and sandflats not covered by seawater at low tide;

Coastal lagoons;

Annual vegetation of drift lines;

Perennial vegetation of stony banks;

Salicornia and other annuals colonising mud and sand; and

Shifting dunes along the shoreline with Ammophila arenaria (“white dunes”).

Annex II species present as a qualifying feature for site selection is:

Desmoulin`s whorl snail, Vertigo moulinsiana.

The conservation objectives of the Solent Maritime SAC as defined in the Regulation 33 advice for the Solent EMS are listed below in Table 5.

Table 5. Conservation objectives for Solent Maritime SAC

Solent Maritime SAC

Estuaries Subject to natural change, maintain the estuaries in favourable condition, in particular, saltmarsh communities, intertidal mudflat and sandflat communities, intertidal mixed sediment communities and subtidal sediment communities.

Annual vegetation of drift lines

Subject to natural change, maintain the annual vegetation of drift lines in favourable condition.

Atlantic salt meadows Subject to natural change, maintain the Atlantic salt meadows (Glauco-Puccinellietalia) in favourable condition, in particular, low marsh communities, mid marsh communities, upper marsh communities and transitional high marshcommunities.

Salicornia Subject to natural change, maintain the Salicornia and other annuals colonising mud and sand in favourable condition, in particular annual Salicornia saltmarsh communities (SM8) and Suaeda maritima saltmarsh communities (SM9).

Cordgrass swards Subject to natural change, maintain the cordgrass swards (Spartinion maritimae) in favourable condition, in particular, small cordgrass (Spartina maritima) communities, smooth cordgrass (Spartina alterniflora) communities and Townsends cordgrass (Spartina x townsendii) communities.

Intertidal mudflats and sandflats

Subject to natural change, maintain the mudflats and sandflats not covered by seawater at low tide in favourable condition, in particular, intertidal mud communities, intertidal muddy sand communities, intertidal sand

Subtidal sandbanks Subject to natural change, maintain the sandbanks which are slightly covered by seawater all the time in favourable condition, in particular, subtidal gravely sand and sand, subtidal muddy sand and subtidal eelgrass Zostera marina beds.

The site is considered to be particularly sensitive to activities or developments which result in loss of habitat through direct removal or coastal squeeze, modification of physical processes and sediment transfer patterns, pollution, and the introduction of non-native species.



APPENDIX 1G - HRA

November 2012

26

River Itchen SAC

The River Itchen was proposed as eligible as an SCI in March 1998, and designated as a SAC in April 2005. The SAC covers 309ha and comprises 40% inland water bodies (standing water, running water), 27% bog, marsh, water fringed vegetation and fens, 19% humid and mesophile grassland, 10% broadleaved deciduous woodland, 2% mixed woodland, 1% improved grassland, and 1% non-forest areas cultivated with woody plants (including orchards, groves, vineyards and dehesas). The boundary of the River Itchen SAC site in the study area is shown in Figure 3.


Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation.

Annex II species that are a primary reason for selection of this site are:

Southern damselfly, Coenagrion mercuriale; and

Bullhead, Cottus gobio.

Annex II species that are a qualifying feature for site selection are:

White-clawed crayfish, Austropotamobius pallipes;

Brook lamprey, Lampetra planeri;

Atlantic salmon, Salmo salar; and

Otter, Lutra lutra.

As the River Itchen SAC does not form part of a European Marine Site, there is no Natural England advice under Regulation 33(2) of the favourable condition targets for qualifying features. However it can be assumed that conservation objectives for the site would be to maintain Annex I habitats for which the site has been designated in a favourable condition, subject to natural change.

Table 6 provides a summary of the interest features and conservation objective habitats designated under the international sites within 5km of the study area.

Table 6. Summary of interest features and conservation objective habitats for designated sites.

European Site Interest Feature Conservation Objective - Habitats

Sand and shingle

Saltmarsh


Annex I species (Common Tern, Little Tern,Mediterranean Gull, Roseate Tern, Sandwich Tern)

Shallow coastal waters


Migratory species (Black-tailed Godwit, Saltmarsh



APPENDIX 1G - HRA

November 2012

27



Boulder and cobble shores

Dark-bellied Brent, Teal, Ringed Plover) and Waterfowl assemblage

Mixed sediment shores

Wet heaths

Dry heaths

Mires

Inland water bodies

Bogs

Marshes

Fens

Woodland

New Forest SPA Annex I species (Hen Harrier, Nightjar, Woodlark, Honey Buzzard and Dartford Warbler) Migratory species (Eurasian Hobby and Wood Warbler).

Grassland

Estuaries

Saline lagoons

Saltmarsh

Atlantic biogeographical region

Intertidal reefs

Saline lagoons

Saltmarsh

Assemblage of rare, vulnerable or endangered species

Cordgrass swards (Spartinion spp.)

Saltmarshes


Boulder & cobble shores

20,000 waterfowl species


Saltmarsh

Sand & shingle

Shallow coastal waters


Boulder and cobble shores


1% or more of the individuals in a population of waterfowl species


Wet heaths

Dry heaths

Mires

Inland water bodies

Bogs

Marshes

Fens

Woodland

New Forest Ramsar Important wetland habitats Internationally important fauna and flora

Grassland

Solent Maritime Estuaries



APPENDIX 1G - HRA

November 2012

28


Annual vegetation of drift lines

Atlantic salt meadows

Salicornia and other annuals colonising mud and sand

Spartina swards


Subtidal sandbanks

Coastal lagoons

Perennial vegetation of stony banks

Shifting dunes along the shoreline with Ammophila arenaria

SAC

Desmoulin`s whorl snail

Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation

Southern damselfly

Bullhead

White-clawed crayfish

Brook lamprey

Otter

River Itchen SAC

Atlantic salmon

Oligotrophic waters containing very few minerals of sandy plains, Littorelletalia uniflorae

Oligotrophic to mesotrophic standing waters with vegetation of the Littorelletea uniflorae and/or of the Isoeto-Nanojuncetea

Northern Atlantic wet heaths with Erica tetralix

European dry heaths

Molinia meadows on calcareous, peaty or clayey-silt-laden soils

Depressions on peat substrates of the Rhynchosporion

Atlantic acidophilous beech forests with Ilex and sometimes also Taxus in the shrublayer

Asperulo-Fagetum beech forests

Old acidophilous oak woods with Quercus robur on sandy plains

Bog woodland

Alluvial forests with Alnus glutinosa and Fraxinus excelsior

Transition mire and quaking bog

Alkaline fen

Southern damselfly

Stag beetle

New Forest SAC

Great crested newt



APPENDIX 1G - HRA

November 2012

29

3.2 Assessment of Likely Significant Effect

3.2.1 Step 3: Potential Impact Pathways

Potential impact pathways that could arise as a result of The Strategy include:

Direct habitat loss;

Saline intrusion;

Changes to coastal processes resulting in morphological changes;

Disturbance; and

Coastal squeeze.

These pathways are broadly consistent with the impact pathways identified in the North Solent SMP, with the addition of direct habitat loss which we have brought in at this strategy level.

Direct habitat loss – The Strategy policies are a combination of holding the existing line or the construction of inland defences. Therefore there will be no direct habitat loss arising from the Strategy. Any impacts to the foreshore arising from construction are likely to be temporary and mitigation can be provided at project level.

Saline intrusion – The Strategy frontage is highly urbanised and there are no protected habitats behind the defences. Therefore there is no impact pathway for saline intrusion.

Changes to coastal processes resulting in morphological changes are considered to be limited for this strategy frontage. This is due to the highly urbanised nature of the frontage and the relatively few formal defences in place. Furthermore The Strategy is proposing an inland defence line along the Southampton Water frontage. Appendix C of the North Solent SMP presents a literature review of the baseline processes within the Solent. It is recognised that with sea level rise, the width and volume of Southampton Water would increase, expanding the tidal prism and initially increasing both flood and ebb velocities. This would tend to increase erosion of the channel margins and the overall sediment flux so that output of both fine suspended and coarse bedload sediments would be greater than at present, thus enlarging the current overall negative sediment budget (New Forest DC, 2010; Appendix C). The North Solent SMP also concluded that over the estuary as a whole there will be no adverse effect on the Solent and Southampton SPA and Ramsar site through changes to coastal processes as the SMP policies will allow the estuaries to expand and naturally evolve (New Forest DC, 2010). Since there are no new defence lines proposed within The Strategy over the next 100 years it is assumed that the preferred policies will not constrain the estuary over and above that considered within the SMP. Therefore coastal processes are not considered further within this assessment.

Disturbance – The Strategy frontage is highly urban and there is little risk of disturbance along the majority of the foreshore. ODU 4 within the River Itchen lies opposite mudflats designated as supporting internationally important Annex I bird species, migratory species and a waterfowl assemblage under the Solent and Southampton Water SPA (see Section 3.1.1). Mudflats along The Strategy frontage within ODU 4, although outside the SPA boundary, probably provide supporting habitat for bird species. In addition the area of Redbridge (ODU 11) lies within the Lower Test Valley and is important for SPA features and identified as a roost site of major importance in the



APPENDIX 1G - HRA

November 2012

30

SMP. However, the short section included in The Strategy is bounded by a railway line and is adjacent to the Redbridge road and rail bridges and therefore is considered to be highly disturbed. Disturbance to birds during construction can be mitigated for through construction programming and good construction practice, avoiding sensitive overwintering periods. However, at the scale of The Strategy plan these effects are not identifiable and mitigation practices would be described in more detail at an individual project level. Therefore disturbance to birds is not considered further as a potential impact pathway within this HRA for The Strategy.

Disturbance through noise and vibration from sheet piling (identified as the preferred option in Unit 2) is also considered as a potential pathway for disturbance to migratory salmon. Disturbance to salmon during construction can be mitigated for through the use of low impact vibro-piling and through the prohibition of construction activities during sensitive migration periods. Migration of juvenile salmon from freshwater out to sea usually takes place between April and June. Multi-sea winter fish (MSW) enter the river again in June to spawn in Autumn and Winter (Hendry & Cragg-Hine, 2003). However, at the scale of The Strategy plan these effects are not identifiable and mitigation practices would be described in more detail at an individual project level. Therefore disturbance to salmon is not considered further as a potential impact pathway within this HRA for The Strategy.

Coastal squeeze is therefore considered the principle impact pathway for The Strategy. Coastal squeeze occurs where a physical structure is in place along the coastline, restricting the ability of intertidal habitats to naturally migrate inland due to sea level rise. Any loss of intertidal habitat will also have implications for bird and fish species so all are reviewed in the context of habitat change as a result of coastal squeeze. The effects of coastal squeeze are discussed in the impact section below (Section 3.2.2).

The Solent CHaMP and North Solent SMP have already considered that coastal squeeze is likely under future epochs over the next 100 years and found that the progressive shift of mean low water has been a consistent trend over large areas of Southampton Water since the 1840s and can be anticipated to continue (Bray and Cottle, 2003).

As discussed in Section 1.2 above, the HRA for the SMP concluded that there would be a significant adverse affect on the European sites due to coastal squeeze. To compensate for this adverse affect managed realignment sites have been identified at Medmerry, East Chidham and Chidam. The cumulative compensation requirements for saltmarsh, freshwater habitats, coastal grazing marsh, estuaries (function) and bird roost and feeding sites for Solent and Southampton Water SPA and Ramsar, and for saltmarsh and estuaries for Solent Maritime SAC will be passed onto the Regional Habitat Creation Programme for delivery. This assessment phase assumes that the coastal squeeze losses identified by the SMP have been fully addressed. The HRA for The Strategy investigates any additional affects to those defined and addressed in the SMP. This reflects the advice from Natural England which is expecting The Strategy to adopt the findings of the SMP and focus on local adjustments where appropriate. In particular, to clarify the situation at areas such as Redbridge where the broad scale SMP policy has been reviewed at a local scale by The Strategy.

Within this HRA for The Strategy, an assessment has been made over whether the preferred options change the predictions that were made under the CHaMP and SMP



APPENDIX 1G - HRA

November 2012

31

for the internationally designated sites. Effects on intertidal habitat loss will be considered across the extent of The Strategy influence on the designated sites.

Sites Screened In/Out

Table 7 summarises the designated sites that have been fully screened in or out at this stage of the HRA process. Since the main impact pathway has been identified as coastal squeeze, firstly any designated sites which only support non-coastal terrestrial habitats and species have been screened out. These include:

New Forest SPA;

New Forest Ramsar; and

New Forest SAC.

The River Itchen SAC is located beyond the tidal limit of the River Itchen at Woodmill (just north of ODU 1). Therefore it can be concluded that there is no direct pathway which could affect designated SAC habitats. However, there is the potential for adverse effects on designated species within the SAC and so the River Itchen has been screened in at this stage.

Table 7. Internationally designated sites within 5km of The Strategy preferred options screened in and out of assessment

Sites screened in Solent and Southampton Water SPA

Solent and Southampton Water Ramsar site Solent Maritime SAC River Itchen SAC

Sites screened out New Forest SPA New Forest Ramsar New Forest SAC

The following section looks at the designated features that occur within each of the ODUs.

3.2.2 Steps 4, 5 and 6: Potential Impacts

The Solent and Southampton Water SPA and Ramsar site and the Solent Maritime SAC have been ‘screened in’ as the designated intertidal habitat occurs within the influence of the Strategy options. Detailed information on these European designated sites was outlined in Section 3.1 including the interest features and conservation objectives for each site. Not all of the interest features of the four ‘screened in’ sites (Table 7) have the potential to be affected by The Strategy.

The following features have been ‘screened out’ of the assessment:

Shallow coastal waters;

Intertidal reefs;

Saline lagoons;

Boulder and cobble shores;

Mixed sediment shores;



APPENDIX 1G - HRA

November 2012

32

Cordgrass swards (Spartinion spp.);

Annual vegetation of drift lines;

Subtidal sandbanks;

Coastal lagoons;

Perennial vegetation of stony banks;

Shifting dunes along the shoreline with Ammophila arenaria;

Water courses of plain to montane levels with the Ranunculion fluitantis and Callitricho-Batrachion vegetation; and

Estuaries.

These features have been screened out for the following reasons:

1. They are not present within the area of influence of The Strategy;

2. The features would not be affected by coastal squeeze; and

3. The estuaries feature has been screened out because the North Solent SMP has concluded that there will be no adverse effect to the estuary as a whole through changes to coastal processes. The Strategy will not introduce any new defence lines and therefore this conclusion stands for the Strategy.

The following habitat features are present within the area potentially affected by coastal squeeze as a result of The Strategy policies and will be considered further in the Appropriate Assessment (AA) (Section 4):

Intertidal mudflats;

Saltmarsh; and

Grazing marsh.

Table 8 summarises the habitats which occur within each ODU, potential impact pathways of The Strategy preferred options on these habitats and whether these habitats have European Designations. In addition to the intertidal mudflat and grazing marsh which occur immediately in front of The Strategy frontage, saltmarsh is also present along the eastern bank of the River Itchen and the western bank of upper Southampton Water. This saltmarsh is also internationally designated under the Solent and Southampton Water SPA and Ramsar site and the Solent Maritime SAC. The potential impacts on the screened in estuaries features including intertidal mudflat, saltmarsh and grazing marsh habitats will be assessed in the AA stage (Section 4) in the context of coastal squeeze, with and without the implementation of The Strategy preferred options. It is important to note that the integrity of the European designated sites as a whole will also be looked at within the AA. The loss of intertidal habitat has potential implications for birds and fish, therefore these features will also be assessed. Table 8 shows that the designated features are present in front of the defences only in ODU 11 (Redbridge).



APPENDIX 1G - HRA

November 2012

33

Table 8. Habitats within each option development unit and designation status

ODU Habitats Within Cross

Section of Unit

Frontage

Preferred Option Potential Impact

Pathway

Designation Status

1 Mudflat 2015-2060: Community and property level flood resistance and resilience 2060-2110: Flood wall near the front line

Coastal squeeze

Not designated

2 Mudflat 2015-2030: Maintain existing defence structures 2030-2110: Steel sheet pile wall at the front line

Coastal squeeze

Solent and Southampton Water SPA and Ramsar* Solent Maritime SAC*

3 Mudflat 2015-2060: Intermediate height flood wall forming the spine of defence until raised land supersedes the floodwall as the main defence by 2060. 2060-2110: Defended by a continuous strip of raised land.

Coastal squeeze


4 Mudflat 2015-2060: Intermediate height flood wall forming the spine of defence until raised land supersedes the floodwall as the main defence by 2060. 2060-2110: Defended by a continuous strip of raised land.

Coastal squeeze


5 Mudflat 2015-2060: Intermediate height flood wall forming the spine of defence until raised land supersedes the floodwall as the main defence by 2060. 2060-2110: Defended by a continuous strip of raised land

Coastal squeeze


6 Mudflat 2015-2110: Defended by raised land implemented through redevelopment.

Coastal squeeze

Not designated

7 Mudflat 2015-2060: Maintain existing quay walls and defence structures 2060-2110: Defended by raised quay walls with floodwall defences along perimeter of ABP land.

Coastal squeeze


8 Mudflat Subtidal habitat

2015-2060: Do nothing 2060-2110: Defended by a floodwall around Ocean Village and along the boundary of the Port.

Coastal squeeze


9 Mudflat Subtidal habitat

2015-2060: Land raising through development of Royal Pier Site and the Major Development Quarter preferred. Implementation of a floodwall forming the spine of the flood defence by 2030 if a continuous strip of raised land is not achieved by this time.

Coastal squeeze




APPENDIX 1G - HRA

November 2012

34

2060-2110: Defended by a floodwall and or raised land.

10 Mudflat Saltmarsh Subtidal habitat

2015-2060: Do nothing. The area behind Port protected against flooding by the existing quay walls in the Port. 2060-2110: Area behind the Port defended against flooding by a floodwall along the boundary of the Port ramps / demountables on access points.

Coastal squeeze


11 Mudflat Saltmarsh Grazing marsh Subtidal mud

2015-2030: Do nothing 2030-2060: Community and property level flood resistance and resilience 2060-2110: Floodwall along the seaward side of the railway embankment.

Coastal squeeze

Solent and Southampton Water SPA and Ramsar Solent Maritime SAC

* Designation falls on opposite side of bank to The Strategy frontage

Intertidal Habitats

A wide range of estuarine habitats are designated within the European Sites which support a complex variety of communities. Loss of habitats and/or communities would be detrimental to the favourable condition of the estuaries feature within the designated sites.

The key sensitivity is the loss or reduction in the extent of habitats. For The Strategy these are; intertidal mudflat, saltmarsh and grazing marsh. There may be a potential adverse effect on these habitats to physical loss through coastal squeeze.

The North Solent SMP, within unit 5c13 in the Lower Test (Redbridge ODU 11), did not take account of coastal squeeze under a policy of NAI as the defence was predicted to fail within the time period 2015-2030. In addition, following advice from Natural England, the SMP did not claim any additional intertidal habitat that might form in the Lower Test over 100 years as a ‘gain’ in terms of EU mitigation or compensation due to the fact that intertidal habitat already exists within this unit. Therefore, at The Strategy level we have assumed that the SMP policy of NAI would not result in the creation of habitats of a suitable quality where the frontage is developed due to the presence of deteriorating infrastructure.

Subtidal Habitats

Over the next 100 years it is not considered that there will be a significant impact on subtidal habitats as the expected sea level rise will increase the habitat area available. This is consistent with the methodology applied throughout the North Solent SMP where marine subtidal beds were not assessed as it was considered that the SMP would not have a significant effect on them (New Forest DC, 2010). Therefore only intertidal habitats will be assessed in the AA (Section 4).

Species

Annex II species designated within the River Itchen SAC include Bullhead, White-clawed (or Atlantic stream) crayfish, Brook lamprey and Otter. The Strategy options will not directly affect these species or the habitats that support them as the SAC lies further upstream than the limit of The Strategy. There is also considered to be no route of



APPENDIX 1G - HRA

November 2012

35

interaction between these freshwater species moving between the River Itchen and the wider Solent Estuary and as such there is considered to be no potential for an adverse effect on these species.

The Desmoulin’s whorl snail (Vertigo moulinsiana) is also an Annex II species, designated under the Solent Maritime SAC. It normally lives on reed-grasses and sedges, such as reed sweet-grass. Like all Annex II Vertigo species, it is highly dependent on maintenance of existing local hydrological conditions and would be sensitive to changes in coastal processes. However, this species has only been recorded within Chichester Harbour (New Forest DC, 2010) and therefore no adverse effect is predicted as a result of The Strategy.

The Strategy preferred options have the potential to affect the migratory Atlantic salmon features of the River Itchen SAC as they pass through Southampton Water. As the River Itchen SAC does not form part of a European Marine Site, there is no Natural England advice under Regulation 33(2) of the favourable condition targets for salmon. However, the study area forms part of the migratory route for salmonids, namely Atlantic salmon and sea trout. Salmon and sea trout are anadromous fish species, migrating firstly as juveniles (smolts) downstream to sea, and again as adult salmon returning upstream to the river to spawn. They are thought to swim near the surface during migratory runs (Moore et al., 1998), and adults display a strong behaviour to return to natal rivers. The rivers in Southampton Water, principally the Test and Itchen, which are designated under the Freshwater Fish Directive (78/659/EEC) are important for migratory salmonids. A potential adverse impact may occur through coastal squeeze as intertidal habitats which provide feeding, spawning and nursery habitat may be affected. In addition juveniles prefer shallow intertidal habitat for movement downstream thus coastal squeeze may have a potential effect on this species.

There is also the potential for changes in water quality and disturbance to salmon as a result of the implementation of The Strategy options. As identified in Section 3.2.1, at the scale of The Strategy plan these effects are not identifiable and would be mitigated for at an individual project level. Therefore these potential impact pathways are not considered further in this HRA.

Birds

The physical loss of key bird habitats may result as a consequence of coastal squeeze. This loss of habitat may result in a potential reduction in habitat suitable for nesting, roosting and feeding, leading to a potential adverse effect on bird species.

Redbridge (ODU 11) lies within the Lower Test Valley which the Solent Waders and Brent Goose Strategy (Hampshire and Isle of Wight Wildlife Trust, 2010) identifies as a high tide roost site of major importance for waders and a feeding and high tide roost site of major importance for Brent Geese and wildfowl. This is also identified within the North Solent SMP. Dark-bellied Brent Geese, as well as other wildfowl, and waders are also designated within the Solent and Southampton Water SPA and Ramsar citations.

Within the North Solent SMP it was considered that any loss of wader and wildfowl feeding and high water roost sites that occurs as a direct result of a strategy option, or as a result of coastal squeeze through a strategy option, will require replacement functioning habitat. Within this HRA for The Strategy any loss of intertidal habitat at Redbridge (ODU 11), over and above that identified within the North Solent SMP, will be



APPENDIX 1G - HRA

November 2012

36

assessed in terms of feeding and high water roost sites for waders and wildfowl and suitable mitigation will be identified where appropriate.

There is also the potential for changes to water quality and disturbance as a result of the implementation of The Strategy options which have the potential to affect bird species through construction. As discussed in Section 3.2.1, at the scale of The Strategy plan these affects are not identifiable and would be mitigated for at an individual scheme level. Therefore these potential impact pathways are not considered further in this HRA.

In summary Table 9 identifies the features to be taken forward to the Appropriate Assessment stage as the potential for a Likely Significant Effect (LSE) has been identified. The identified features have been assessed in the context of the proposed Southampton Strategy options and a list of actions proposed to quantify effects in more detail.

Table 9. LSE of policies on identified interest features and proposed actions to quantify effects

Interest Features For Which There is a LSE

Preferred Option LSE Action

Intertidal mudflat Do nothing Maintain existing defence structure Flood resistance and resilience Flood wall Raised land

Negative effect due to coastal squeeze.

Saltmarsh Do nothing Maintain existing defence structure Flood resistance and resilience Flood wall Raised land

Negative effect due to coastal squeeze

Grazing marsh Do nothing Maintain existing defence structure Flood resistance and resilience Flood wall Raised land

Negative effect due to coastal squeeze

Negative effect due to loss of supporting habitat through coastal squeeze

Atlantic Salmon Do nothing Maintain existing defence structure Flood resistance and resilience Flood wall Raised land Negative effect due to

disturbance

Negative effect due to loss of supporting habitat through coastal squeeze

Bird species (as identified)

Do nothing Maintain existing defence structure Flood resistance and resilience Flood wall Raised land Negative effect due to

disturbance

Assess The Strategy implications for coastal squeeze over and above SMP.



APPENDIX 1G - HRA

November 2012

37

4 STEP 8: APPROPRIATE ASSESSMENT

From Section 3.2.2 above, it was concluded that coastal squeeze as a result of The Strategy has the potential to significantly affect the following habitats and species designated under the Solent and Southampton Water SPA and Ramsar site and the Solent Maritime SAC (see Table 9):

Habitats:

Intertidal mudflat;

Saltmarsh; and

Grazing marsh.

Species:

Atlantic salmon; and

Bird species (overwintering and migratory).

To assess the impacts of coastal squeeze on habitats and species designated under European sites over and above those defined in the SMP, the likely intertidal habitat changes have been determined by modelling water level changes throughout the Estuary. Comparisons have been made between a ‘baseline’ scenario and a ‘preferred option’ scenario. The baseline scenario is one in which water levels have been calculated if no new defences were constructed and as such any impacts on intertidal habitats are a result of climate change and natural processes over time. The preferred option scenario calculates water levels with The Strategy preferred options in place over the duration of the plan. The difference between calculated water levels under the two scenarios will give an indication of the potential hydrodynamic changes which will result from The Strategy. Implications for designated habitats and species can then be inferred.

4.1.1 Strategy Assessment of Coastal Squeeze

As noted above, to determine if The Strategy options alter the conclusions of the SMP HRA, numerical modelling has been undertaken to determine how the implementation of The Strategy options change water levels. The modelling uses the Mike11 hydrodynamic model used to define the flood envelopes and hence define the options. The model was run for the baseline scenario (no defences) and with The Strategy preferred options in place.

Assuming a baseline year of 2010, the impact of climate change under both scenarios was accounted for by allowing for the EA 2011 sea level rise guidance (See Appendix K) and these are presented in Table 10.

Table 10: EA 2011 Medium emission scenario 95%tile change allowances for relative mean sea level

Year EA 2011 Added Water Levels (cm)

2030 11

2060 31

2110 73



APPENDIX 1G - HRA

November 2012

38

The results of the model revealed that there is no change in water levels with and without The Strategy options in place until the time period 2060 to 2110. This is due to the fact that a sea level rise of 31cm (as a result of climate change) up until 2060 will not overtop the existing structures in place along the Southampton frontage, for example ABP quay walls. Therefore there will be no effect along the frontage as a result of The Strategy to 2060.

By 2110, the difference in peak water levels at high water between a ‘Do Nothing’ scenario and with the Strategy implemented is shown in Table 11 for each ODU. The biggest increases in water levels as a result of The Strategy options are expected to occur towards the top of the tidal limit of the River Itchen and at Redbridge within upper Southampton Water. A maximum increase 0.5cm in water levels in 2110 was calculated with and without The Strategy preferred options in place. Smaller increases are estimated further downstream, with changes as little as 0.1cm calculated at Netley shore (to the south of The Strategy frontage on the Eastern Shore of Southampton Water). Downstream of Netley no differences in water level changes were estimated with or without The Strategy options in place, indicating that Netley Shore is the maximum extent of influence of The Strategy.

A maximum increase in water levels of 0.5cm should be considered minimal within the context of 100 years and a predicted sea level rise of 73cm due to climate change (see Table 10). Furthermore, the Solent and Southampton Water is an extremely complex system with a large number of human activities taking place and hence subject to huge variability. Following a precautionary approach, an assessment of the influence of these changing water levels has been undertaken.



APPENDIX 1G - HRA

November 2012

39

Table 11. Maximum difference in water levels at high water in 2110 under a baseline scenario (no defences) and a preferred option scenario (with defences).

ODU Difference (Preferred option – baseline)

(cm)

1 0.5

2 0.5

3 0.5

4 0.4

5 0.3

6 0.3

7 0.2

8 0.3

9 0.3

10 0.4

11 0.5

Using the results of the water level changes, the effects on intertidal habitat changes have been inferred along the length of Southampton Water and the River Itchen. The effects on estuary features have been looked at through the change in intertidal habitat, which in the case of The Strategy includes mudflat and saltmarsh, and grazing marsh. Water levels under the two scenarios, baseline and preferred option, have been compared to assess the effects on intertidal habitat specifically as a result of The Strategy.

4.2 All ODUs: 2010 to 2060

Due to the fact that there is no change in water levels between the two scenarios until the time period 2060 to 2110, it can be concluded that differences in intertidal habitat as a result of The Strategy will only be observed after this period. Therefore The Strategy options will have no adverse effects on the integrity of designated habitats, including intertidal habitats (as identified in Table 8) and associated species, as a result of coastal squeeze prior to 2060, outwith those already identified and addressed through the SMP and Southern Regional Habitat Creation Programme.

4.3 ODUs 1-7 (River Itchen): 2060 to 2110

Designated intertidal mudflat only occurs on the opposite bank of the River Itchen to The Strategy frontage. Within the River Itchen (ODUs 1-7) the model calculated up to a 0.5cm increase in maximum water levels by 2110 with The Strategy preferred options in place, compared to without (Table 11). There would be no differences in low water levels between the two scenarios. Due to the fact that the designated intertidal habitat within the River Itchen occurs below MHW an increase of 0.5cm in water levels above the baseline at high water will not affect the area of intertidal.

Furthermore, along this frontage there already exists vertical or near vertical walls. Therefore a maximum water level increase of 0.5cm against a vertical wall will not result in any additional coastal squeeze to that already identified in the SMP under a policy of Hold the Line for these units.



APPENDIX 1G - HRA

November 2012

40

Due to the fact that the River Itchen is highly developed and constrained on both sides The Strategy does not change the future evolution of the River Itchen and no additional intertidal habitat is lost as a result of The Strategy options in place up to 2110, over and above that identified under the North Solent SMP. Therefore, coastal squeeze due to water level increases as a result of The Strategy preferred policies will have no adverse effect on the integrity of European Sites in the River Itchen over and above those accounted for and offset through the SMP.

4.4 ODUs 8-10 (Southampton Water): 2060 to 2110

Along the immediate frontage of ODUs 8 to 10 no intertidal habitat is present due to the presence of Southampton Docks, but designated intertidal habitat, including mudflat and saltmarsh, does occur on the opposite bank of Southampton Water to that of The Strategy frontage (at Marchwood and Dibden). Within Southampton Water (ODUs 8 – 10) the model calculated an increase in maximum water levels of 0.4cm by 2110 with The Strategy options in place, compared to without (Table 11). The Strategy options will not affect the non-designated subtidal habitats along this frontage. There is substantial intertidal habitat fronting the sea walls along the opposite bank on the western side of Southampton Water, however, due to the fact that this designated intertidal habitat occurs below MHW an increase of 0.4cm in maximum water levels above the baseline at high water will not affect the area of intertidal on the opposite bank.

Under the North Solent SMP for these units a preferred policy of Hold the Line has been identified. As a similar option of a set back flood defence is also the preferred option for these ODUs under The Strategy it is assumed that there will be no additional loss of intertidal mudflat and saltmarsh due to coastal squeeze along this bank. Furthermore it is assumed that the existing port infrastructure will be maintained. Therefore The Strategy will have no adverse effects on the integrity of European designated sites, over and above that already identified and accounted for within the SMP.

4.5 ODU 11 (Redbridge): 2060 to 2110

ODU 11 at Redbridge is the only ODU where The Strategy frontage is internationally designated. The area is a mosaic of grazing marsh and intertidal channels. The two bridges that cross the River act as a constriction for water from Southampton Water through the submerged weir and bathymetry of the area, therefore creating very different hydrodynamics as compared to the Itchen and Southampton Water frontages. Due to the topography of the intertidal area at Redbridge and the numerous channels which run through the area, intertidal habitat will not increase/decrease in a linear way throughout the 100 year epoch as a result of sea level rise, as it would along an open coast.

As a guide to this change GIS has been used to overlay LiDAR data at Redbridge with water level increases to predict changes in intertidal habitat between 2010 and 2110 under a baseline scenario (no defences) (see Figure 4). From this Figure it can be seen that although areas that are intertidal in 2010 will be converted to subtidal habitat by 2110 due to sea level rise, other areas of grazing marsh in 2010 will be converted to intertidal mudflat and saltmarsh by 2110. Under a baseline scenario (no new defences) this results in an overall increase in intertidal habitat (mudflat and saltmarsh) area within and around ODU 11 by 2110, but a decrease in grazing marsh. The area of grazing marsh converted to intertidal habitat in front of The Strategy frontage by 2110 is approximately 1ha of which most will be mudflat along with a small area of saltmarsh.



APPENDIX 1G - HRA

November 2012

41

Therefore with or without any sea defences along this frontage, approximately 1ha of grazing marsh will be converted to intertidal habitat due to sea level rise.

Within The Strategy, this area (ODU 11) has a preferred option between 2060 and 2110 of implementation of a floodwall in order to protect properties, the rail infrastructure and a former landfill site at Redbridge from flooding. Thus the Mean High Water line will be prohibited from ‘rolling back’ over the top of the railway embankment. Under the North Solent SMP this area (5c13) has a preferred policy of NAI throughout the 100 year timeline. Between 2060 and 2110 water levels are high enough to over top the existing railway line embankment, currently acting as a defacto defence.

Thus a policy of No Active Intervention would in theory allow the intertidal habitat to ‘roll back’, overtopping the railway line and creating a new area of intertidal habitat (approximately 0.2ha) behind the railway line (Figure 4). However, it should be noted that the proportion of the SMP Policy Unit (5c13) defended through the implementation of a floodwall within ODU 11 is less than 15% with a preferred policy of NAI. A change in intertidal habitat composition in front of the railway line will still occur with a transition from grazing marsh to intertidal mudflat and saltmarsh.

The potential for up to 0.2 ha of intertidal habitat to be created behind the railway under the SMP NAI policy would not occur under The Strategy preferred option between 2060 and 2110.

The current conclusion using the best scientific information available is that there is a risk that there will be an adverse effect on intertidal habitat after 2060 and so this potential impact will need to be factored into the strategic habitat creation programme in due course. There will however need to be further detailed investigation of this potential impact in a future revision of The Strategy and this will quantify and describe the impact in order to inform habitat compensation requirements.

Since The Strategy preferred option differs from SMP policy for this epoch it will also be necessary for this to be taken into account in the next revision of the SMP.

The loss of grazing marsh in front of the defence line would occur with or without The Strategy preferred option in place and therefore The Strategy would have no adverse effect on coastal grazing marsh, over and above that identified in the SMP.



APPENDIX 1G - HRA

November 2012

42

Figure 4. Change in intertidal area under latest sea level rise guidance (EA 2011) by 2110.



APPENDIX 1G - HRA

November 2012

43

4.6 Atlantic Salmon

It can be concluded that there will be no adverse effect on Atlantic salmon as the intertidal habitats which support these species are not affected by coastal squeeze as a result of The Strategy options. Any loss of feeding or nursery habitat, as well as morphological changes affecting migration routes will be considered in more detail at an individual project level and mitigated for as required.

4.7 Birds

Loss of grazing marsh at Redbridge (ODU 11) due to sea level rise has the potential to displace wader and wildfowl species from their feeding and roost sites identified as being of major importance within the Solent Wader and Brent Goose Strategy. However, the loss of grazing marsh has been identified as a consequence of sea level rise and not the implementation of The Strategy. Therefore it has been concluded that The Strategy preferred option will have no adverse effect on bird species supported by grazing marsh, over and above that identified within the SMP. Additionally the potential for mitigation and environmental enhancement in creating grazing marsh has been identified within the playing fields at Redbridge. It has also been concluded that there will be no adverse effect of The Strategy options throughout the rest of the study area (ODU 1 to 10) on bird species (as identified in Section 3.1) as the intertidal habitats which support these species are not affected by coastal squeeze, over and above that identified within the North Solent SMP.

4.8 Overall Study Area

For Southampton Water as a whole there is expected to be no change in water levels before 2060. There is the potential for a minimal change in maximum water levels across the entire site as a result of the preferred option scenario between 2060 and 2110, when compared to a baseline scenario. Due to the inherent inaccuracies of the model and uncertainty in sea level rise predictions, overall increases are deemed insignificant. Therefore there is predicted to be no adverse effect on intertidal habitats and associated species, over and above those identified and addressed within the SMP, and no adverse effect on the integrity of European sites. This conclusion will be reinvestigated in the future with regard to ODU 11 given the acknowledged potential for an adverse effect (post 2060) in that area.

In summary it can be concluded that The Strategy will have no adverse effect on the following designated sites:

Solent and Southampton SPA;

Solent and Southampton Ramsar;

Solent Maritime SAC; and

River Itchen SAC.

However, it is also concluded that a reinvestigation and analysis will be required for ODU 11 before the flood wall preferred option is implemented in that area.

4.9 Cumulative and In-Combination Impacts

The Habitats Regulations require that, in determining whether a plan or project is likely to have a significant effect on a European site, the plan or project should be considered



APPENDIX 1G - HRA

November 2012

44

both alone and in-combination with other plans or projects. However, given the uncertainties that exist about how and when The Strategy options will be implemented, it is recognised that this exercise is necessarily limited and that the assessment of in-combination effects will need to be revisited and addressed in a more comprehensive way at the project-level.

By way of guidance and direction to project-level HRAs, the potential sources of in-combination effects to The Strategy plan include the following relevant projects, plans and activities:

The Test and Itchen Catchment Abstraction Management Strategy;

River Itchen, Weston Shore, Netley & Hamble Coastal Defence Strategy Study;

North Solent Shoreline Management Plan; and

Port of Southampton Dredging Works.

The Test and Itchen Catchment Abstraction Management Strategy (CAMS) sets out how much water is available in the catchment and details the Environment Agency’s policies and actions relating to the management of this water. It describes actions the Environment Agency will take to ratify its findings and work towards possible solutions. The CAMS could have an additional influence on water levels through existing and future abstraction licenses and discharge consents, which would need to be considered in more detail within a project level HRA.

The River Itchen, Weston Shore, Netley & Hamble CDS forms a continuous boundary with The Strategy along the River Itchen. The HRA for the River Itchen, Weston Shore, Netley & Hamble CDS indicates that there will be no impact on the integrity of any European site, including the Solent and Southampton Water SPA and Ramsar site, the Solent Maritime SAC and the River Itchen SAC. It has been concluded that there will be no impact on these designated sites in-combination with The Strategy.

This HRA for The Strategy has been considered within the wider context of the North Solent SMP. With the exception of Redbridge (ODU 11), preferred policies within the SMP are identical to the options within The Strategy. As mentioned in Section 1.2 adverse effects of the SMP on habitats will be compensated for within the Southern RHCP. The Strategy preferred option at Redbridge, may lead to a loss of 0.2 ha of intertidal habitat over and above that identified within the SMP, which will need to be factored into the strategic habitat creation programme in due course

The Port of Southampton is proposing to undertake two major projects to ensure that the Port of Southampton remains competitive and successful as a major port into the future. The first of these projects is a capital dredge to improve the navigational accessibility to the Port of Southampton and involves selective deepening and widening of the navigation channel at various locations through Southampton Water and the Solent. The second proposal is to reconfigure and deepen part of the Western Docks fronting the container terminal at Berths 201 and 202 to enable the Port to accommodate the current generation of large container vessels at their loaded draught. Works are expected to commence on this project by July 2012 and the new berths should be operational by January 2014. The design of the proposed projects has been optimised with a view to avoiding and/or minimising environmental impacts where possible. EIAs for both projects have shown that in most cases the impacts will be either insignificant or minor and that, where larger adverse impacts are likely to occur,



APPENDIX 1G - HRA

November 2012

45

they can be mitigated such that the residual impacts will be reduced to acceptable levels. Impacts from these proposed projects are unlikely to add any additional pressures to the integrity of designated sites in combination with The Strategy preferred options. In fact, the dredging activities will increase the depth of the channel. The EIAs for both projects indicate that this will tend to marginally reduce HW levels in the Southampton Strategy area thus offsetting any potential effect attributable to The Strategy preferred options themselves.

It is acknowledged that wider issues may also cause additional pressures impacting on the integrity of European sites. These include pressures arising from new housing and recreational requirements expected over the next 20 years. These pressures are currently the subject of research by the Solent Forum. In addition, associated river and coastal infrastructure (moorings, slipways, and Sewage Treatment Works, etc) could lead to potential habitat and water quality effects. The in-combination impacts of these projects will be dealt with in more detail at a project level, where appropriate.

4.10 Step 9: Mitigation

There is the opportunity for mitigation and environmental enhancement within the Redbridge scheme through topographical modifications of the frontage and associated grazing marsh in areas behind the railway line adjacent to ODU 11. The potential for any adverse effect on European designated features will be considered further as part of a future revision of The Strategy prior to 2060. At that point, if it is concluded that an adverse effect would in fact occur, the effect will either have to be avoided or a case for ‘no alternatives’ or IROPI be made to the Secretary of State and compensation secured. The potential loss of up to 0.2ha of intertidal habitat should therefore be factored in to the next round of Strategic Habitat Mitigation as this may need to be considered in combination with other losses elsewhere along the Solent frontages. This will also be investigated at a project level and if necessary appropriate mitigation measures will be identified.

Since The Strategy preferred option for ODU 11 differs from SMP policy for this epoch it will also be necessary for this to be taken into account in the next revision of the SMP.



APPENDIX 1G - HRA

November 2012

46

5 REFERENCES

Bray, M. and Cottle, R., 2003. The Solent Coastal Habitat Management Plan (CHaMP) Final Report – Volumes 1 and 2. Royal Haskoning.

English Nature, 2001. English Nature’s advice for the Solent European Marine Site given under Regulation 33(2) of the Conservation (Natural Habitats &c.) Regulations 1994. 18 October 2001.

English Nature, 1997. Habitats Regulations Guidance Note 1 (HRGN 1) May 1997.

Hendry K & Cragg-Hine D., 2003. Ecology of the Atlantic Salmon. Conserving Natura 2000 Rivers Ecology Series No. 7. English Nature, Peterborough.

New Forest District Council, 2010. North Solent Shoreline Management Plan. Available to download at: http://www.northsolentsmp.co.uk/index.cfm?articleid=9907&articleaction=nthslnt &CFID=36021649&CFTOKEN=74467137 Accessed: 15/08/11

http://www.northsolentsmp.co.uk/index.cfm?articleid=9907&articleaction=nthslnt&CFID=36021649&CFTOKEN=74467137

http://www.northsolentsmp.co.uk/index.cfm?articleid=9907&articleaction=nthslnt&CFID=36021649&CFTOKEN=74467137

southampton coastal flood and erosion risk management strategy coastal... · southampton coastal...

Documents