23.0 tidal lagoon swansea bay
TRANSCRIPT
23.0 Tidal Lagoon Swansea Bay
Water Framework Directive
Screening
July 2013
Tidal Lagoon Swansea Bay plc
Tidal Lagoon Swansea Bay
Water Framework Directive Screening
Contents
1.0 Water Framework Directive - Screening.....................................1
1.1 Introduction ................................................................................1
1.2 Overview of Project ....................................................................1
1.3 Consenting Process .....................................................................2
1.4 Overview of the Project ..............................................................2
2 The Water Framework Directive ................................................6
2.1 Introduction ................................................................................6
2.2 Methodology ..............................................................................6
2.3 Study Area (Stage 1) ...................................................................7
2.4 WFD Baseline (Stage 2) ............................................................ 11
2.5 Relationship of the Proposed Development to relevant
WFD Waterbodies (Stage 3) .................................................... 15
2.6 WFD Preliminary Assessment (Stage 4) ................................... 18
2.7 WFD Detailed Assessment (Stage 5) ........................................ 23
Appendix 1 Water Framework Directive Article 4.7
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Water Framework Directive Screening Page 1
1.0 Water Framework Directive - Screening
1.1 Introduction
1.1.0.1 This assessment has been prepared in support of the PEIR published in relation to a
prospective DCO application for the Tidal Lagoon Project1 in Swansea Bay with a nominal
rated capacity of 240MW. A summary of the Project is provided below and a detailed
description of the proposed development can be found in Chapter 4: Project Description
of the PEIR.
1.1.0.2 During pre-application consultation, Natural Resources Wales (NRW) indicated that a
Water Framework Directive (WFD) Screening Assessment was required to form part of
the Environmental Impact Assessment. A WFD Screening Assessment determines
whether a proposed development is compliant with the objectives of the WFD, or if
further assessment is required. This assessment, therefore, screens the Project and its
component elements against the WFD.
1.2 Overview of Project
1.2.0.1 TLSB is proposing to construct and operate a tidal energy lagoon, located in Swansea Bay,
South Wales (Figure 1.1). The tidal lagoon will generate renewable energy in the form of
electricity using the large tidal range (the difference between high and low water) which
is a distinguishing feature of the Bay. The lagoon will have a rated capacity of 240
Megawatts (MW), generating 400GWh net annual output. This is enough electricity for
approximately 121,000 homes: more than Swansea’s annual domestic electricity use
(109k households); c.70% of Swansea Bay’s annual domestic electricity use (Swansea,
Neath & Port Talbot, 173k households); or c.9% of Wales’ annual domestic electricity use
(based on 1,369k households).
Figure 1.1: Location of proposed tidal lagoon
1 Definitions used in this [Report] are, so far as possible, the same as those used in the PEIR.
Tidal Lagoon Swansea Bay plc
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Water Framework Directive Screening Page 2
1.2.0.2 In addition to generating electricity, the Project also aims to provide visitor facilities and
other amenities including art, education, mariculture and sporting/recreational facilities.
The seawall is expected to be open to the public during daylight hours for walking, running,
cycling etc, though access will be controlled in extreme weather.
1.3 Consenting Process
1.3.0.1 As the Project is an offshore electricity generating station of more than 100MW, it is
considered to be a Nationally Significant Infrastructure Project (NSIP) under the Planning
Act 2008. Construction of such a project requires that a DCO is first granted by the
Secretary of State for Energy and Climate Change via an application to the Planning
Inspectorate (PINS) under the 2008 Act.
1.3.0.2 The Project is located in Welsh coastal waters and therefore it also requires a marine
license to be granted via an application to the Marine Licensing Team of Natural Resources
Wales (NRW) on behalf of the Welsh Government. Additional consents may also be
required from the local planning authorities – City & County of Swansea Council (CCSC) or
Neath Port Talbot County Borough Council (NPTCBC) – for elements of the Project which sit
outside the NSIP and DCO. Table 1.1 below summarises the components and consenting
requirements of the Project.
Table 1.1: Summary schedule of consents
Group of works Description Consenting process
Offshore Works The turbines, with their housing and other facilities such as
generators and switchgear; seawall enclosing the new lagoon;
provision for roll-on/roll-off ferry berthing facility; integral
visitor centre, leisure facilities and public realm; emergency
and operational facilities; dredging works; works to Swansea
Port Channel; works to Neath Harbour Channel; works to
existing long sea outfall; navigation facilities; ecological
enhancement and mitigation; and navigational/lighting
works.
These works will be authorised by
the DCO and, to the extent they are
marine works, will require a marine
licence. The consent would include
powers to construct temporary
works such as cofferdams or
lighting.
Grid Connection
Works
The cable works embedded in the seawall; cable from the
landfall of the Offshore Works to the existing Baglan
substation in Neath Port Talbot; and a cable crossing of the
River Neath by direct drilling (going underneath the river).
These works will be authorised by
the DCO. The cable crossing of the
River Neath will require a marine
licence.
Onshore Works Provision of a temporary working area, access routes and
road accesses for construction of the Project;
decontamination works; operation and maintenance (O&M)
facilities, with slipways; vehicle parking and manoeuvring
areas; onshore visitor and recreational facilities; and right-of-
way and seashore works/mitigation within the lagoon
including treatment of storm water and interfaces with
Crymlyn Burrows SSSI.
These parts of the Project will be
authorised by the DCO.
Access Works Provision of access to the Project including necessary
demolitions; swing bridge(s); cycle routes; highway
improvements; and other works.
These parts of the Project will be
authorised by the DCO, but may
also be the subject of applications
to local planning authorities under
the TCPA 1990.
1.4 Overview of the Project
1.4.1.1 In order to control the flow of seawater to generate electricity, the Tidal Lagoon will be
built by forming a 9.5km-long, U-shaped seawall (Figure 1.1) running from Swansea Port
out to sea before curving back to re-join land adjacent to Swansea University’s new Science
and Innovation Campus (SAIC). Access to the Project, and supporting onshore facilities at
these two (Swansea Port and Campus) landfalls, will be from Fabian Way.
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Water Framework Directive Screening Page 3
1.4.1.2 The seawall will have a sediment core held in place by a casing of sediment-filled geotextile
tubes, known as Geotubes®. The outside of the structure will be covered in rock armour of
various sizes, depending on its level of exposure (Figure 1.2). The sand used to form the
walls will be taken from within the lagoon footprint. Rock armour will then be brought in
by sea to provide protection. The top of the seawall will have an access road which will be
used for operation and maintenance of the lagoon as well as for visitors.
Figure 1.2: Example cross-section through lagoon seawall
1.4.0.3 In the south-western part of the seawall there will be a turbine/sluice gate housing
structure (Figure 1.1). The housing structure will contain between 16 and 22 hydro (water)
turbines, which will be permanently underwater (Figure 1.3). These turbines (which will be
7m-8m in diameter) will generate electricity on both the flood (in-coming) and ebb (out-
going) tides. There will also be around 10 sluice gates – these are large gates which will be
underwater and able to let seawater in and out of the lagoon without going through the
turbines, as required.
Figure 1.3: Cross-section of turbine housing structure
1.4.0.4 To generate electricity, as the sea starts to rise (flood tide) from low tide level, water is
prevented from entering the lagoon for an average of 2 hours 5 minutes, and this creates a
difference in water levels known as ‘head’. Once sufficient head has been reached, the
water is allowed to flow into the lagoon through the turbines, turning the runner (like a
propeller) and generating electricity. This process is repeated on the ebb tide, where the
water is prevented from leaving the lagoon until there is sufficient head to start the
process again (Figure 1.4).
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Water Framework Directive Screening Page 4
Figure 1.4: Illustration of water flow between the sea and the lagoon
1.4.0.5 Towards the end of the ebb or flood tide the sluice gates will be opened. This is to empty
or fill the lagoon as quickly as possible before low or high tide level. By doing this, it
ensures that the lagoon water level is as close to the outside sea level as possible, before
the tide starts to rise or fall again. This is to maximise electricity generation and to keep the
intertidal area as close as possible to that occurring naturally outside the lagoon. An option
to pump the seawater at the end of the tide is also being looked at to further equalise
seawater levels.
1.4.1.6 This generation sequence will happen on both the flood and ebb tides, four times a day in
total. Figure 1.5 below illustrates this generating cycle.
Figure 1.5: Indicative 48-hour operating cycle for the lagoon
1.4.0.7 The electricity generated from the lagoon will be transported to the nearest National Grid
substation at Baglan by underground cables. The cables will be laid in the seawall and then
alongside existing roads/paths to the River Neath and onto the substation. To cross the
River Neath, the cable will either be put through existing disused pipes or it will be drilled
underneath the river.
1.4.1.8 At the end of the lifetime of the project (120 years) there are a number of potential
options for decommissioning and these are outlined below.
a. At the end of the working life of the facility, the turbines and sluice gates could be
removed, and the tide allowed to flow through the resultant gaps in the structure.
b. An alternative to this approach would be to remove a section of the breakwater bund
seawall from landfall of the eastern arm to where it meets the River Neath Cannel. The
other breakwater bunds would remain and the Lagoon would continue to be used for
Leisure.
Tidal Lagoon Swansea Bay
Water Framework Directive Screening
c. As identified above if
requirements of the community and the Local Planning Authorities, requires removal of
sections of the breakwater bund, then this would be undertaken either by the use of
barge mounted excavators with con
large sections of the breakwater were to be removed then an option would be to
remove the sediment with a Cutter Suction Dredger, after removal of the rock armour
and underlayer.
d. It is equally likely that
generation by tidal Lagoons will have further developed, and the Swansea Tidal Lagoon
will be progressively updated so that the facility can be kept in use as an energy source
as well as its ongoing leisure use.
1.4.0.9 The components of the Project considered relevant to the WFD assessment comprise:
i. Construction dredging
ii. The lagoon walls and other offshore structure
iii. The turbine housing and
iv. Inlet channels and scour protection;
v. The water area within the proposed lagoon / offshore public realm;
vi. Emergency facilities and slipways (onshore and offshore);
vii. Operation and maintenance facilities, visitors centre including parking;
viii. Connection to the electricity grid; and
ix. Terrestrial ancillary in
cycle routes and parking).
1.4.0.10 The location of the proposed d
Figure 1.6 Location of the proposed Swansea Bay Tidal Lagoon
Tidal Lagoon Swansea Bay plc
As identified above if the ongoing use of the Lagoon, as determined by the
requirements of the community and the Local Planning Authorities, requires removal of
sections of the breakwater bund, then this would be undertaken either by the use of
barge mounted excavators with conventional land based excavators and dumpers. If
large sections of the breakwater were to be removed then an option would be to
remove the sediment with a Cutter Suction Dredger, after removal of the rock armour
It is equally likely that at the nominal end of the working life of this facility, power
generation by tidal Lagoons will have further developed, and the Swansea Tidal Lagoon
will be progressively updated so that the facility can be kept in use as an energy source
ngoing leisure use.
of the Project considered relevant to the WFD assessment comprise:
Construction dredging;
The lagoon walls and other offshore structures;
The turbine housing and turbines;
Inlet channels and scour protection;
ter area within the proposed lagoon / offshore public realm;
Emergency facilities and slipways (onshore and offshore);
Operation and maintenance facilities, visitors centre including parking;
Connection to the electricity grid; and
Terrestrial ancillary infrastructure (public realm facilities, highways infrastructure,
cycle routes and parking).
proposed development is shown in Figure 1.6.
Location of the proposed Swansea Bay Tidal Lagoon
Page 5
the ongoing use of the Lagoon, as determined by the
requirements of the community and the Local Planning Authorities, requires removal of
sections of the breakwater bund, then this would be undertaken either by the use of
ventional land based excavators and dumpers. If
large sections of the breakwater were to be removed then an option would be to
remove the sediment with a Cutter Suction Dredger, after removal of the rock armour
at the nominal end of the working life of this facility, power
generation by tidal Lagoons will have further developed, and the Swansea Tidal Lagoon
will be progressively updated so that the facility can be kept in use as an energy source
of the Project considered relevant to the WFD assessment comprise:
ter area within the proposed lagoon / offshore public realm;
Operation and maintenance facilities, visitors centre including parking;
frastructure (public realm facilities, highways infrastructure,
Location of the proposed Swansea Bay Tidal Lagoon
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Water Framework Directive Screening Page 6
2 The Water Framework Directive
2.1 Introduction
2.1.0.1 The Water Framework Directive (2000/60/EC) was given effect in the UK by the Water
Environment (Water Framework Directive) (England and Wales) Regulations 2003.
2.1.0.2 The WFD was put in place to:
a) Enhance the status, and prevent further deterioration of aquatic ecosystems and
associated wetlands which depend on the aquatic ecosystems;
b) Promote the sustainable use of water;
c) Reduce pollution of water, especially by ‘priority’ and ‘priority hazardous’
substances; and
d) Ensure progressive reduction of groundwater pollution2.
2.1.0.3 The WFD sets the objectives for all waterbodies in Europe classified under the WFD and the
requirement that they should reach at least good status (or potential) by 2015. This date
has been extended to 2027 in respect of a large number of waterbodies. Around 20% of
waterbodies in England in Wales are currently meeting the objective.
2.1.0.4 The WFD required member states to establish river basin districts and, for each, a
management plan. In Wales, as in England, WFD-related actions are managed through the
River Basin Management Plan (RBMP) process. For the Project, the relevant RBMP is the
Western Wales RBMP. The first Western Wales RBMP was published by Environment
Agency Wales in 2009 and is currently being updated by Natural Resources Wales.
Waterbody Action Plans (WAPs) are also available and these summarise the key features
and objectives of the waterbody along with updated information on the current status
WFD between revisions of the RBMPs.
2.1.0.5 The WFD has important implications for planning works that may affect relevant
waterbodies. It has the effect of controlling such development to circumstances where it
does not cause deterioration in waterbody status (ideally, such development should
improve the status of the affected waterbodies).
2.1.0.6 The WFD provides that, in the event that a proposed development would result in an
adverse effect on a waterbody, which could cause a deterioration in its WFD status or
could prevent actions which are required to raise the WFD status of the waterbody, then
the proposed development must be assessed and justified, in the context of the actions
proposed to mitigate the adverse impact on the status of the waterbody3.
2.2 Methodology
2.2.0.1 In order to assess whether the Project is compliant with the objectives set out in the WFD,
the following steps have been undertaken, or will be undertaken as part of preparation of
the Application for a DCO:
2 http://ec.europa.eu/environment/water/water-framework/
3 Water Framework Directive (2000/60/EC) Article 4.7
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Water Framework Directive Screening Page 7
i. Stage 1 – Defining the study area, based on the distance of waterbodies from the
Project and the hydrological connectivity of waterbodies to the Project (discounting
those waterbodies not considered to be relevant);
ii. Stage 2 – Collating baseline data on the screened-in waterbodies, their current WFD
status, their specific objectives and any mitigation measures or failures undertaken to
date;
iii. Stage 3 – Defining the relationship of the Project's components with the included
waterbodies (screening out components not considered to be relevant);
iv. Stage 4 – A preliminary assessment of the remaining components of the Project
against the WFD elements (biological, chemical and hydromorphological element that
make up the overall WFD status) of the included waterbodies. This is to identify
whether any components could have an impact on the WFD elements and whether a
detailed assessment is required;
v. Stage 5 (if required) – Undertake a detailed assessment based on the findings of the
preliminary assessment in respect of any components of the Project identified as likely
to have an impact upon the WFD elements. This assessment will also consider any
conflicts between the Project and relevant RBMP mitigation measures, and any
cumulative effects of the development;
vi. Stage 6 (if Stage 5 required) – Proposed programme of compliance of development,
required in accordance with Article 4.7 of the WFD (Article 4.7 of the WFD is provided
in Appendix 1).
2.3 Study Area (Stage 1)
2.3.0.1 The Project will be situated within the Western Wales River Basin District and within the
Ogmore to Tawe Catchment.
2.3.0.2 Coastal waterbodies, transitional (estuarine) waterbodies, river waterbodies and
groundwater waterbodies that are adjacent, upstream and downstream of the Project
are shown below in relation to the proposed development in Figures 2.1, 2.2, 2.3 and 2.4
respectively, and their waterbody IDs provided.
2.3.1 Coastal
2.3.1.1 Coastal waterbodies that have been identified, adjacent or near to the proposed
development, are:
a) Swansea Bay (Coastal waterbody, GB641008260000)
b) Bristol Channel Outer North (Coastal waterbody, GB611008590001)
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Figure 2.1 WFD Waterbodies – Coastal
2.3.2 Transitional (Estuarine)
2.3.2.1 Transitional (or estuarine) waterbodies that have been identified, adjacent or near to the
proposed development, are:
a) Tawe Estuary (Estuarine waterbody, GB541005900900)
b) Neath Estuary (Estuarine waterbody, GB541005800700)
Figure 2.2 WFD Waterbodies – Transitional (Estuarine)
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2.3.3 River
2.3.3.1 River waterbodies that have been identified, adjacent or near to the proposed
development, are:
i. River Neath - confluence with Nedd Fechan and Mellte to tidal limit (River waterbody,
GB110058032430)
ii. River Tawe - confluence with Twrch to tidal limit (River waterbody, GB110059032180)
iii. River Tawe – confluence with Nant Cwmgelli to tidal limit (River waterbody,
GB110059025690)
iv. Crymlyn Brook – Headwater to confluence with Tennant Canal (River waterbody,
GB110059025700)
v. Neath and Tennant (River waterbody, GB71010012).
Figure 2.3 WFD Waterbodies - Rivers
2.3.4 Groundwater
2.3.4.1 A groundwater waterbody that has been identified, adjacent or near to the proposed
development, is:
a) Swansea Carboniferous Coal Measures (Groundwater waterbody, GB41002G201000)
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Figure 2.4 WFD Waterbodies - Groundwater
2.3.5 Conclusions
2.3.5.1 The five WFD rivers identified above (GB110058032430, GB110059032180,
GB110059025690, GB110059025700 and GB71010012) are upstream of the proposed
development, and beyond the tidal limit, and therefore are not hydrologically connected
to the proposed development. Consequently, it is not considered that they will be
affected by the proposed development and they are not considered further within this
assessment.
2.3.5.2 The majority of construction and operation relating to the Project will be located within
the marine environment, and there exists the potential for pollution prevention measures
to control construction impacts for the terrestrial infrastructure components (see
Chapter 17). As such, Swansea Carboniferous Coal Measures Groundwater Waterbody
(GB41002G201000) is not considered likely. Notwithstanding this a small potential to
affect the saline wedge has been identified (Chapter 18 of the PEIR) and this is being
investigated further during the EIA.
2.3.5.3 Therefore, those waterbodies that comprise the study area, and that are considered
further within this assessment, are:
a. Swansea Bay (Coastal, GB641008260000);
b. Bristol Channel Outer North (Coastal, GB611008590001);
c. Tawe Estuary (Transitional, GB541005900900);
d. Neath Estuary (Transitional, GB541005800700); and
e. Swansea Carboniferous Coal Measures (Groundwater, GB41002G201000).
2.3.5.4 These are the waterbodies that are at greatest risk of being affected by the proposed
development.
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2.4 WFD Baseline (Stage 2)
2.4.0.1 This section provides the WFD baseline conditions for those waterbodies comprising the
study area.
2.4.0.2 WFD baseline data on the assessed waterbodies is presented in Table 2.1. Information
presented is taken from the Western Wales RBMP (Appendix B) and the updated
Waterbody Action Plans (WAPs), provided to TLSB by Natural Resources Wales on 2 May
2013. Note that red text indicates WFD failures.
T
ida
l La
go
on
Sw
an
sea
Ba
y p
lc
Tid
al La
go
on
Sw
an
sea
Ba
y
Wa
ter
Fra
me
wo
rk D
ire
ctiv
e S
cre
en
ing
P
ag
e 1
2
Ta
ble
2.1
WF
D B
ase
lin
e D
ata
(E
stu
ari
es,
Co
ast
al
Wa
ters
, G
rou
nd
wa
ter)
Wa
terb
od
y
ID
No
.
an
d n
am
e
Est
ua
rin
e
Co
ast
al
Wa
ter
Gro
un
dw
ate
r
GB
54
10
05
90
09
00
Ta
we
Est
ua
ry
GB
54
10
05
80
07
00
Ne
ath
Est
ua
ry
GB
64
10
08
26
00
00
Sw
an
sea
Ba
y
GB
61
10
08
59
00
01
Bri
sto
l C
ha
nn
el
Ou
ter
No
rth
GB
41
00
2G
20
10
00
Sw
an
sea
C
arb
on
ife
rou
s
Co
al
Me
asu
res
Cla
ssif
ied
as
He
av
ily
Mo
dif
ied
?
Ye
s Y
es
Ye
s N
o
N/A
Cu
rre
nt
Ov
era
ll
Po
ten
tia
l
Go
od
G
oo
d
Mo
de
rate
(W
ate
rbo
dy
Act
ion
Pla
n)
Ba
d (
RB
MP
)
Go
od
(W
ate
rbo
dy
Act
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Pla
n)
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de
rate
(RB
MP
)
Po
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(Ov
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ll C
lass
)
Go
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(Q
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tati
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Cla
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ive
(Ov
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Go
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by
20
15
G
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d b
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01
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by
20
27
G
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02
7
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20
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Sp
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(s)
Go
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by
20
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Go
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, G
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mic
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20
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Go
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Ch
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l b
y 2
02
7
Just
ific
ati
on
if
ov
era
ll o
bje
ctiv
e i
s
no
t g
oo
d s
tatu
s b
y
20
15
N/A
– w
ate
rbo
dy
is
me
eti
ng
ob
ject
ive
N/A
– w
ate
rbo
dy
is
me
eti
ng
ob
ject
ive
Dis
pro
po
rtio
na
tely
exp
en
siv
e.
Te
chn
ica
lly
infe
asi
ble
Dis
pro
po
rtio
na
tely
exp
en
siv
e.
Dif
fuse
so
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e p
oll
uti
on
.
Min
es
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d m
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wa
ters
Pro
tect
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Are
a
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sig
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atm
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nt
Sta
tus:
Ba
d
Pre
dic
ted
Sta
tus
by
20
15
:
Ba
d
Ph
yto
pla
nk
ton
: C
urr
en
t
Sta
tus:
Hig
h
Pre
dic
ted
Sta
tus
by
20
15
: H
igh
(W
AP
)
An
ne
x 8
: H
igh
(W
AP
)
Te
rre
stri
al
eco
syst
em
s -
pro
ba
bly
a r
isk
.
Info
rma
tio
n o
n
sup
po
rtin
g c
he
mic
al
ele
me
nts
Cu
rre
nt
Ch
em
ica
l S
tatu
s –
“Do
es
No
t R
eq
uir
e
Ass
ess
me
nt”
Cu
rre
nt
Sta
tus
– G
oo
d
Dis
solv
ed
o
xyg
en
–
Cu
rre
nt
sta
tus:
Hig
h
Pre
dic
ted
sta
tus
by
20
15
:
Hig
h
1,2
-dic
hlo
roe
tha
ne
–
Dis
solv
ed
in
org
an
ic n
itro
ge
n
– M
od
era
te (
curr
en
t),
Mo
de
rate
(p
red
icte
d)
Dis
solv
ed
oxy
ge
n –
Hig
h
(cu
rre
nt)
, H
igh
(p
red
icte
d)
Co
pp
er
– H
igh
(cu
rre
nt)
,
Dis
solv
ed
In
org
an
ic
Nit
rog
en
:
Cu
rre
nt
Sta
tus:
Go
od
(WA
P)
Dis
solv
ed
Oxy
ge
n
Cu
rre
nt
Sta
tus:
Hig
h
(WA
P)
Fro
m R
MP
No
t a
t ri
sk -
Nit
rate
.
Pro
ba
bly
no
t a
t ri
sk f
or
dif
fuse
pe
stic
ide
s;
ph
osp
ho
rou
s, c
hlo
rin
ate
d
sub
sta
nce
, h
aza
rdo
us
sub
sta
nce
.
T
ida
l La
go
on
Sw
an
sea
Ba
y p
lc
Tid
al La
go
on
Sw
an
sea
Ba
y
Wa
ter
Fra
me
wo
rk D
ire
ctiv
e S
cre
en
ing
P
ag
e 1
3
Wa
terb
od
y
ID
No
.
an
d n
am
e
Est
ua
rin
e
Co
ast
al
Wa
ter
Gro
un
dw
ate
r
GB
54
10
05
90
09
00
Ta
we
Est
ua
ry
GB
54
10
05
80
07
00
Ne
ath
Est
ua
ry
GB
64
10
08
26
00
00
Sw
an
sea
Ba
y
GB
61
10
08
59
00
01
Bri
sto
l C
ha
nn
el
Ou
ter
No
rth
GB
41
00
2G
20
10
00
Sw
an
sea
C
arb
on
ife
rou
s
Co
al
Me
asu
res
Cu
rre
nt
sta
tus:
Hig
h
Pre
dic
ted
sta
tus
by
20
15
:
Hig
h
Hig
h (
pre
dic
ted
) T
olu
en
e –
Hig
h (
curr
en
t),
Hig
h (
pre
dic
ted
)
Info
rma
tio
n o
n
sup
po
rtin
g
con
dit
ion
s (H
yd
ro-
mo
rph
olo
gic
al)
Tid
al
Re
gim
e -
Fre
shw
ate
r
Flo
w.
Cu
rre
nt
sta
tus
-
“Su
pp
ort
s G
oo
d”
Pre
dic
ted
sta
tus
by
20
15
–
“Su
pp
ort
s G
oo
d”
Tid
al
Re
gim
e -
Fre
shw
ate
r
Flo
w.
Cu
rre
nt
sta
tus
-
“Su
pp
ort
s G
oo
d”
Pre
dic
ted
sta
tus
by
20
15
–
“Su
pp
ort
s G
oo
d”
No
in
form
ati
on
pro
vid
ed
wit
hin
RB
MP
or
WA
P
Mo
rph
olo
gy
Cu
rre
nt
Sta
tus:
Su
pp
ort
s
Go
od
Pre
dic
ted
Sta
tus
by
20
15
: S
up
po
rts
Go
od
No
t a
t ri
sk -
Sa
lin
e
intr
usi
on
.
Hy
dro
log
ica
l
rela
tio
nsh
ip w
ith
pro
po
sed
de
ve
lop
me
nt
Pro
po
sed
de
ve
lop
me
nt
is
loca
ted
pa
rtly
wit
hin
th
e
wa
terb
od
y
Pro
po
sed
de
ve
lop
me
nt
is
loca
ted
pa
rtly
wit
hin
th
e
wa
terb
od
y
Cro
sse
s th
e m
ari
ne
com
po
ne
nts
of
the
pro
po
sed
de
ve
lop
me
nt
Th
e p
rop
ose
d
de
ve
lop
me
nt
is l
oca
ted
insh
ore
wit
hin
th
e
ad
jace
nt
wa
terb
od
y
Th
e p
rop
ose
d
de
ve
lop
me
nt
is l
oca
ted
wit
hin
th
e g
rou
nd
wa
ter
bo
dy
are
a.
Ad
dit
ion
al
info
rma
tio
n f
rom
the
Wa
terb
od
y
Act
ion
Pla
ns
(WA
Ps)
Wa
terb
od
y i
s co
nsi
de
red
at
risk
of
ph
ysi
cal
or
mo
rph
olo
gic
al
alt
era
tio
n a
s a
resu
lt o
f d
red
gin
g.
W
ate
rbo
dy
is
con
sid
ere
d
pro
ba
bly
at
risk
of
po
int
sou
rce
po
llu
tio
n a
s a
re
sult
fro
m d
an
ge
rou
s su
bst
an
ces
an
d s
an
ita
ry d
ete
rmin
an
ds,
an
d a
lso
fro
m d
iffu
se s
ou
rce
po
llu
tio
n a
s a
re
sult
of
nu
trie
nt
nit
rog
en
.
Wa
terb
od
y i
s co
nsi
de
red
at
risk
of
ph
ysi
cal
or
mo
rph
olo
gic
al
alt
era
tio
n
as
a r
esu
lt o
f d
red
gin
g.
W
ate
rbo
dy
is
als
o
con
sid
ere
d p
rob
ab
ly a
t
risk
fro
m p
oin
t a
nd
dif
fuse
sou
rce
po
llu
tio
n a
s a
resu
lt o
f o
rga
nic
en
rich
me
nt
an
d s
an
ita
ry
de
term
ina
nd
s.
Wa
terb
od
y i
s co
nsi
de
red
pro
ba
bly
at
risk
of
dif
fuse
sou
rce
po
llu
tio
n a
s a
re
sult
of
nu
trie
nt
nit
rog
en
, a
nd
fro
m p
hy
sica
l o
r
mo
rph
olo
gic
al
alt
era
tio
n a
s
a r
esu
lt f
rom
sh
ore
lin
e
stru
ctu
res.
Wa
terb
od
y i
s
con
sid
ere
d p
rob
ab
ly a
t
risk
of
ph
ysi
cal
or
mo
rph
olo
gic
al
alt
era
tio
n a
s a
re
sult
of
dre
dg
e s
po
il
rep
lace
me
nt.
It
is a
lso
con
sid
ere
d p
rob
ab
ly a
t
risk
fro
m i
nv
asi
ve
spe
cie
s.
Wa
ter
Bo
dy
Pro
ba
bly
no
t
at
risk
- D
iffu
se S
ou
rce
Urb
an
& T
ran
spo
rt
Pre
ssu
re
Dri
nk
ing
, W
ate
r
an
d A
bst
ract
ion
.
N
ote
– t
ext
in
re
d i
nd
ica
ted
WF
D f
ail
ure
Tidal Lagoon Swansea Bay plc
Tidal Lagoon Swansea Bay
Water Framework Directive Screening Page 14
2.4.0.3 The WFD baseline information in Table 2.1 shows that, overall the Swansea Bay Coastal
Waterbody is failing under the WFD, on the basis of phytoplankton and dissolved
inorganic nitrogen. The Swansea Carboniferous Coal Measures, the Neath Estuary, Tawe
Estuary and Bristol Channel Outer North Coastal Waterbody are meeting the WFD
objective of Good Status.
2.4.0.4 In the context of the WAPs, Swansea Bay is considered to be at risk of failing to meets its
WFD objectives as a result of enhanced levels of nutrient nitrogen, and also because of
coastal morphological changes, due to shoreline structures. This is likely because of the
urbanised nature of the land surrounding Swansea Bay, including the conurbations of
Swansea and Port Talbot.
WFD Mitigation Measures for Waterbodies
2.4.0.5 Information in Appendix B of the Western Wales RBMP (Waterbody status objectives)
suggests that all relevant mitigation measures are in place for the Neath Estuary and
Tawe Estuary. However, the current WFD failure at Swansea Bay means that there is a
number of mitigation measures which are not in place in respect of this waterbody , as
set out in Appendix B of the RBMP. These mitigation measures, should they be
implemented, could improve the WFD status of the waterbody. The mitigation measures
are:
a. Indirect / offsite mitigation (offsetting measures);
b. Alter timing of dredging / disposal;
c. Reduce sediment resuspension;
d. Reduce impact of dredging;
e. Prepare a dredging / disposal strategy;
f. Avoid the need to dredge (e.g. minimise under-keel clearance; use fluid mud
navigation; flow manipulation or training works);
g. Operational and structural changes to locks, sluices, weirs, beach control, etc;
h. Preserve and where possible enhance ecological value of marginal aquatic habitat,
banks and riparian zone;
i. Managed realignment of flood defence;
j. Bank rehabilitation / reprofiling;
k. Preserve and, where possible, restore historic aquatic habitats;
l. Removal of hard bank reinforcement or replacement with soft engineering solution;
and
m. Remove obsolete structure.
2.4.0.6 The Project has been designed to take into consideration the requirements of the WFD.
The following mitigation measures and enhancements are proposed to reduce overall
potential effects of the project through all of its life stages and to provide benefits to the
WFD waterbodies status where relevant to the Project. Further mitigation measures will
be developed where appropriate during the EIA:
Tidal Lagoon Swansea Bay plc
Tidal Lagoon Swansea Bay
Water Framework Directive Screening Page 15
i. All construction works would be undertaken in accordance with relevant legislation
and good practice guidance for the protection of surface and groundwater, which
would ensure that there is no degradation in WFD objectives during the construction
phase;
ii. Construction site drainage would be carefully designed and controlled, with silt traps
established at the outset of the works, which would ensure that there is no
degradation in WFD objectives during the construction phase;
iii. It would be proposed that, prior to construction of the Offshore Works commencing,
invasive species would be removed as far as practical from within the footprint of the
Offshore Works. This would offer net benefits to the WFD waterbodies. These
presence of invasive species would be identified as part of the benthic survey, and an
invasive non-native species (INNS) management plan would be implemented during
the construction phase;
iv. The re-introduction of native oyster to the area would be encouraged, which would
offer benefits to the WFD waterbodies;
v. New rocky reef would be incorporated into the proposed development, which would
offer benefits to the WFD waterbodies;
vi. It is proposed that a lobster hatchery be developed and lobsters be introduced onto
the rocky reef, which would offer benefits to the WFD waterbodies;
vii. Opportunities for fisheries would be investigated, which would offer benefits to the
WFD waterbodies. At present, this would include the new reef habitat that will be
provided as part of the development;
viii. Options for reducing the potential effects of the intermittent storm discharge through
the existing outfall are being investigated. This would provide improvements to
bathing water quality and Shellfish Waters Directive4; and
ix. Potential introduction of surface “soft” landscaping within the existing coastal rock
armouring.
2.4.0.7 Further opportunities for enhancement measures, for example draped dunes and
saltmarsh, will be investigated during the EIA phase of the project.
2.5 Relationship of the Proposed Development to relevant WFD Waterbodies (Stage 3)
2.5.0.1 This section provides more information about the components of the proposed
development and their relationship to the WFD waterbodies included in this assessment.
This section determines whether the components of the proposed development have
potential to affect the WFD objectives of the five waterbodies.
2.5.0.2 Where the components of the proposed development are relevant to the WFD's
objectives, those components are taken forward to Stage 4 of this assessment
(Preliminary Assessment). If the components of the proposed development are not
considered relevant to the WFD, they are not taken forward to Stage 4 and are screened
out at this stage.
2.5.0.3 Table 2.2 presents further details of the elements associated with the proposed
development and their relationships with the WFD waterbodies identified above.
4 The European Community Shellfish Waters Directive (2006/113/EC)
T
ida
l La
go
on
Sw
an
sea
Ba
y p
lc
Tid
al L
ag
oo
n S
wa
nse
a B
ay
Wa
ter
Fra
me
wo
rk D
ire
ctiv
e S
cre
en
ing
P
ag
e 1
6
Ta
ble
2.2
Re
lati
on
ship
of
the
Pro
ject
co
mp
on
en
t w
ith
re
lev
an
t W
FD
wa
terb
od
ies
De
ve
lop
me
nt
Co
mp
on
en
t
An
tici
pa
ted
wo
rks
wit
hin
/ d
ire
ctly
ad
jace
nt
to W
FD
Wa
terb
od
ies
De
tail
s /
Co
mm
en
ts
Re
lev
an
t to
WF
D?
Lag
oo
n w
all
s.
Co
nst
ruct
ion
a
nd
lo
ng
te
rm p
rese
nce
of
Lag
oo
n w
all
s w
ith
in t
he
Sw
an
sea
Ba
y
Co
ast
al
Wa
terb
od
y a
nd
Ca
rbo
nif
ero
us
Co
al
Me
asu
res.
Pa
rtly
ad
jace
nt
to t
he
Bri
sto
l C
ha
nn
el
Ou
ter
No
rth
Co
ast
al
Wa
terb
od
y,
Ne
ath
Est
ua
ry a
nd
Ta
we
Est
ua
ry.
Co
nst
ruct
ion
in
volv
es:
• D
red
gin
g t
o p
rovi
de
se
dim
en
t fi
lle
d
ge
ote
xtil
e t
ub
es;
• D
red
gin
g t
o p
rovi
de
an
in
fill
of
sed
ime
nt,
fro
m t
he
la
go
on
fo
otp
rin
t; a
nd
• O
ute
r p
rote
ctio
n o
f ro
ck a
rmo
ur
of
vari
ou
s
gra
de
s.
Pre
sen
ce o
f la
go
on
wa
lls
wil
l a
lte
r co
ast
al
pro
cess
es
an
d t
he
refo
re a
ffe
ct e
xist
ing
hy
dro
mo
rph
olo
gy
.
Ye
s –
con
stru
ctio
n o
f la
go
on
wa
lls
wo
uld
ha
ve
po
ten
tia
l sh
ort
-te
rm i
mp
act
on
its
ch
em
istr
y a
nd
bio
log
y.
Pre
sen
ce o
f w
all
s d
uri
ng
op
era
tio
n
wo
uld
ha
ve a
po
ten
tia
l lo
ng
-te
rm i
mp
act
on
th
e
hy
dro
mo
rph
olo
gy
an
d b
iolo
gy
of
the
Sw
an
sea
Ba
y C
oa
sta
l W
ate
rbo
dy
.
No
eff
ect
an
tici
pa
ted
on
Ca
rbo
nif
ero
us
Co
al
Me
asu
res
Gro
un
dw
ate
r.
Tu
rbin
e h
ou
sin
g,
inle
t ch
an
ne
ls a
nd
sco
ur
pro
tect
ion
.
Co
nst
ruct
ion
an
d o
pe
rati
on
wit
hin
th
e
Sw
an
sea
Ba
y C
oa
sta
l W
ate
rbo
dy
.
Th
e t
urb
ine
s a
nd
slu
ice
ga
tes
wo
uld
be
ho
use
d w
ith
in t
his
co
mp
on
en
t, w
hic
h i
s to
be
loca
ted
in
th
e s
ou
th w
est
ern
po
int
of
the
bre
ak
wa
ter
wa
ll.
Th
e h
ou
sin
g w
ou
ld b
e u
p t
o
55
0m
lo
ng
an
d i
s cu
rre
ntl
y e
xpe
cte
d t
o h
ou
se
be
twe
en
16
– 2
2 t
urb
ine
s.
Th
e t
urb
ine
ho
usi
ng
wil
l b
e t
he
ma
in
exc
ava
tio
n o
f th
e s
ea
be
d w
ith
th
e i
nle
t
cha
nn
els
on
th
e g
rad
ien
t le
ad
ing
do
wn
to
it.
Sco
ur
pro
tect
ion
wil
l b
e p
lace
d i
n t
his
are
a.
Ye
s –
co
nst
ruct
ion
on
th
e s
ea
be
d w
ill
ha
ve a
po
ten
tia
l sh
ort
-te
rm i
mp
act
on
its
ch
em
istr
y.
Th
ere
wil
l b
e a
po
ten
tia
l lo
ng
-te
rm i
mp
act
on
th
e
hy
dro
mo
rph
olo
gy
an
d b
iolo
gy
of
the
Sw
an
sea
Ba
y C
oa
sta
l W
ate
rbo
dy
, d
uri
ng
th
e o
pe
rati
on
al.
Alt
ho
ug
h u
nli
ke
ly (
Ch
ap
ter
18
of
the
PE
IR)
po
ten
tia
l e
ffe
ct o
n s
alt
we
dg
e a
nd
Ca
rbo
nif
ero
us
Co
al
Me
asu
res
Gro
un
dw
ate
r w
ill
be
fu
rth
er
inve
stig
ate
d.
Lag
oo
n w
ate
r a
rea
/ o
ffsh
ore
pu
bli
c
rea
lm.
Co
nst
ruct
ion
an
d o
pe
rati
on
ad
jace
nt
to
an
d w
ith
in t
he
Sw
an
sea
Ba
y C
oa
sta
l
Wa
terb
od
y,
an
d a
dja
cen
t to
th
e T
aw
e
Est
ua
ry.
Th
is a
rea
wo
uld
be
a w
ate
rsp
ort
ve
nu
e,
wit
hin
th
e l
ag
oo
n w
all
s, a
s th
ey
wo
uld
pro
vid
e a
sa
fe b
od
y o
f w
ate
r.
No
– a
s th
ere
wil
l b
e m
inim
al
con
stru
ctio
n w
ith
in
the
wa
terb
od
ies,
be
st p
ract
ice
po
llu
tio
n
pre
ven
tio
n b
ein
g d
ep
loy
ed
wo
uld
mit
iga
te a
ny
po
ten
tia
l im
pa
ct.
Em
erg
en
cy f
aci
liti
es
an
d s
lip
wa
ys
(on
sho
re a
nd
off
sho
re).
Co
nst
ruct
ion
an
d o
pe
rati
on
wit
hin
th
e
Sw
an
sea
Ba
y C
oa
sta
l W
ate
rbo
dy
.
Th
ese
fa
cili
tie
s w
ou
ld h
ou
se e
me
rge
ncy
bo
ats
wit
h s
lip
wa
y a
cce
ss,
on
e b
ase
d o
n t
he
we
ste
rn s
ide
of
the
la
go
on
an
d p
ote
nti
all
y
on
e o
n t
he
ea
ste
rn s
ide
.
No
– a
ny
co
nst
ruct
ion
wit
hin
th
e S
wa
nse
a B
ay
Co
ast
al
Wa
terb
od
y w
ill
pri
ma
rily
be
on
th
e
lag
oo
n w
all
s (c
on
sid
ere
d s
ep
ara
tely
ab
ove
).
Op
era
tio
n a
nd
ma
inte
na
nce
faci
liti
es,
bo
ati
ng
cen
tre
/ vi
sito
rs
Co
nst
ruct
ion
an
d o
pe
rati
on
wit
hin
th
e
Ta
we
Est
ua
ry W
ate
rbo
dy
an
d a
dja
cen
t to
the
Sw
an
sea
Ba
y C
oa
sta
l W
ate
rbo
dy
.
Loca
ted
on
th
e w
est
ern
sid
e o
f th
e l
ag
oo
n,
ad
jace
nt
to t
he
la
nd
.
No
– m
inim
al
con
stru
ctio
n a
dja
cen
t to
wa
terb
od
y,
tho
ug
h l
oca
lise
d t
em
po
rary
dre
dg
ing
to a
llo
w a
cce
ss a
t a
ll s
tate
s o
f ti
de
. T
his
dre
dg
ing
wil
l b
e a
sse
sse
d w
ith
in t
he
la
go
on
wa
ll.
T
ida
l La
go
on
Sw
an
sea
Ba
y p
lc
Tid
al L
ag
oo
n S
wa
nse
a B
ay
Wa
ter
Fra
me
wo
rk D
ire
ctiv
e S
cre
en
ing
P
ag
e 1
7
De
ve
lop
me
nt
Co
mp
on
en
t
An
tici
pa
ted
wo
rks
wit
hin
/ d
ire
ctly
ad
jace
nt
to W
FD
Wa
terb
od
ies
De
tail
s /
Co
mm
en
ts
Re
lev
an
t to
WF
D?
faci
liti
es
incl
ud
ing
pa
rkin
g.
Be
st p
ract
ice
po
llu
tio
n p
rev
en
tio
n b
ein
g
de
plo
ye
d w
ou
ld m
itig
ate
an
y p
ote
nti
al
imp
act
.
Co
nn
ect
ion
to
th
e
ele
ctri
city
gri
d
Co
nst
ruct
ion
wit
hin
th
e S
wa
nse
a B
ay
Co
ast
al
Wa
terb
od
y a
nd
Ca
rbo
nif
ero
us
Co
al
Me
asu
res
Gro
un
dw
ate
r, a
dja
cen
t to
the
Ta
we
Est
ua
ry W
ate
rbo
dy
an
d w
ith
in
the
Ne
ath
Est
ua
ry W
ate
rbo
dy.
Th
e e
lect
rica
l o
utp
ut
fro
m t
he
tu
rbin
es
wo
uld
be
tra
nsf
err
ed
to
th
e B
ag
lan
su
bst
ati
on
to
th
e
ea
st o
f N
ea
th E
stu
ary
, vi
a t
hre
e c
ab
les,
la
id
un
de
rgro
un
d i
n a
sin
gle
tre
nch
. T
he
ro
ute
wo
uld
be
wit
hin
th
e l
ag
oo
n w
all
an
d t
he
n
foll
ow
exi
stin
g l
ine
ar
rou
tes
(ro
ad
s/p
av
em
en
ts)
un
til
it p
ass
es
thro
ug
h
Cry
mly
n B
urr
ow
s S
SS
I e
ith
er
alo
ng
or
ad
jace
nt
to t
he
exi
stin
g t
arm
ac
tra
ck.
It w
ill
the
n c
ross
th
e N
ea
th e
stu
ary
to
re
ach
Ba
gla
n s
ub
sta
tio
n.
On
sho
re –
No
– A
ll
con
stru
ctio
n a
sso
cia
ted
wit
h
lay
ing
ca
ble
alo
ng
th
e p
rop
ose
d g
rid
co
nn
ect
ion
rou
te w
ou
ld b
e s
ub
ject
to
be
st p
ract
ice
po
llu
tio
n
pre
ven
tio
n m
ea
sure
s, w
hic
h a
re c
on
sid
ere
d
suff
icie
nt
to m
itig
ate
an
y i
mp
act
up
on
WF
D
wa
terb
od
ies.
Cro
ssin
g o
f N
ea
th E
stu
ary
wil
l e
ith
er
be
by
th
e
use
of
exi
stin
g i
nfr
ast
ruct
ure
or
by
dir
ect
ion
al
dri
ll a
nd
, w
ith
sta
nd
ard
go
od
co
nst
ruct
ion
pra
ctic
e,
wil
l n
ot
aff
ect
th
e N
ea
th E
stu
ary
.
Off
sho
re –
No
– T
he
off
sho
re c
on
stru
ctio
n w
ill
be
wit
hin
th
e n
ew
ly i
nst
all
ed
la
go
on
wa
lls
so l
imit
ed
imp
act
s a
re e
xpe
cte
d o
n W
FD
wa
terc
ou
rse
s, a
nd
be
st p
ract
ice
po
llu
tio
n p
reve
nti
on
me
asu
res
are
con
sid
ere
d s
uff
icie
nt
to m
itig
ate
an
y i
mp
act
s.
De
sig
n w
ou
ld e
nsu
re h
yd
rolo
gic
al
lin
ks
wo
uld
be
ma
inta
ine
d.
Te
rre
stri
al
An
cill
ary
Infr
ast
ruct
ure
(pu
bli
c re
alm
faci
liti
es,
hig
hw
ay
s
infr
ast
ruct
ure
an
d
cycl
e r
ou
tes)
Co
nst
ruct
ion
an
d o
pe
rati
on
wit
hin
Ca
rbo
nif
ero
us
Co
al
Me
asu
res
Gro
un
dw
ate
r a
nd
pa
rtly
wit
hin
th
e
Sw
an
sea
Ba
y C
oa
sta
l W
ate
rbo
dy
, N
ea
th
an
d T
aw
e E
stu
ary
Wa
terb
od
ies.
All
on
sho
re.
Fo
r fu
rth
er
info
rma
tio
n o
n t
he
de
tail
s o
f th
is i
nfr
ast
ruct
ure
, p
lea
se s
ee
Ch
ap
ter
4:
Pro
ject
De
scri
pti
on
.
No
– s
tan
da
rd p
oll
uti
on
pre
ven
tio
n m
ea
sure
s
be
ing
de
plo
ye
d w
ou
ld m
itig
ate
an
y i
mp
act
(Ch
ap
ter
17
of
the
PE
IR f
or
Gro
un
dw
ate
r).
Tidal Lagoon Swansea Bay plc
Tidal Lagoon Swansea Bay
Water Framework Directive Screening Page 18
2.5.0.4 The information in Table 2.2 demonstrates those components of development
considered to potentially be relevant to the WFD objectives of the relevant waterbodies,
and these are:
a) Lagoon Walls (construction and operation); and
b) Turbine Housing with Inlet Channels and Scour Protection (construction and
operation).
2.5.0.5 These components are therefore screened into the preliminary assessment and are taken
forward to Stage 4.
2.5.0.6 All other components of the proposed development are screened out of the preliminary
assessment, and not taken forward for assessment at Stage 4, as it is not considered that
they could inhibit the waterbodies included within the study area achieving, or continuing
to achieve, the WFD objectives.
2.6 WFD Preliminary Assessment (Stage 4)
2.6.0.1 This section reports the preliminary assessment. It assesses each component of the
proposed development that has been identified as being relevant to the WFD against the
waterbodies comprised in the study area. The assessment has been undertaken on the
basis of whether the works undertaken as part of the Project are likely to result in:
1. Failure to achieve, good ecological status or good ecological potential within the
waterbody;
2. Failure to prevent any deterioration in groundwater status, ecological status or
ecological potential within the waterbody;
3. Permanent exclusion of, or compromised achievement of, WFD objectives in the
waterbody (or other waterbodies);
4. Non-compliance or compromised implementation of other EU legislation; and
5. Prevention of the waterbody in meeting any of the mitigation measures specified in
the RBMP, either now or in the future.
2.6.0.2 In general, construction of the Project will have a temporary effect on the surrounding
environment, for example impacts in respect of noise and increased suspended solids.
However, there would be longer term effects associated with construction, such as
permanent loss of habitat beneath the footprint of the proposed development. During
operation, longer term effects are anticipated, some negative and others potentially
positive.
2.6.0.3 An assessment of the components of the Project (identified in Table 2.2 above) will be
undertaken for both the construction and operation phase. The results of these
assessments are presented in Table 2.3 and Table 2.4 respectively. These tables provide a
matrix of the potential effects of those screened in components of the proposed
development against the WFD Elements for Transitional, Coastal and Ground Water
bodies, as listed in the relevant section of River Basin Management Plan Western Wales
River Basin District Annex B: Water body status objectives WFD.
Tidal Lagoon Swansea Bay plc
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Water Framework Directive Screening Page 19
Table 2.3 Preliminary Assessment of Project components against WFD elements during
construction
WFD Elements Lagoon Walls Turbine Housing, Inlet Channels &
Scour Protection
Biological Quality
Elements
(comprising
phytoplankton,
other aquatic flora
(macrophytes and
phytobenthos),
benthic invertebrate
fauna and fish
fauna)
Swansea Bay, Bristol Channel
Outer North, Tawe Estuary, Neath
Estuary
Temporary noise, vibration and re-
suspension of sediment (reducing
oxygen, releasing contaminants)
during construction of the lagoon
walls could potentially impact upon
marine ecology. Direct loss of
habitat under the footprint of the
proposed development. Further
assessment will be undertaken
during the EIA.
Swansea Bay
The construction of the turbine
housing/inlet area will require the
formation of a temporary cofferdam so
that the main works can be
undertaken in the dry. Depending on
its type (sand bund, steel cofferdam,
etc.) the temporary impacts will vary.
The potential impacts of this will be
assessed further during the EIA.
Dry construction of the turbine house
will minimise potential impacts.
The removal of the cofferdam and final
formation of the inlet channels could
impact upon the aquatic flora and
fauna, which will be identified within
the EIA. Further assessment will also
be undertaken during the EIA.
Chemical and
physico-chemical
elements
comprising:
transparency,
thermal conditions,
oxygenation
conditions, salinity,
nutrient conditions,
and specific
pollutants.
Swansea Bay, Bristol Channel
Outer North, Tawe Estuary, Neath
Estuary
Dredging for the construction of
the lagoon walls, and disturbance
of the seabed could result in
increased sediment being re-
suspended into the water column.
This sediment could contain
contaminants that would
detrimentally affect water
chemistry. Further assessment will
be undertaken during the EIA.
Swansea Bay
Depending on the option selected, the
formation and removal of the
cofferdam may have similar impact to
that of the lagoon wall, and will be
further assessed within the EIA.
The dry construction of turbine
housing/ inlet channel is not
considered likely to have any
significant impact on the chemical
status of the waterbodies during
construction, assuming best-practice
pollution control measures are
adopted.
Hydromorphological
elements
comprising:
morphological
conditions (depth
variation; quantity,
structure and
substrate of the
bed; structure of
the intertidal zone)
and tidal regime
(freshwater flow,
wave exposure).
Swansea Bay, Tawe Estuary, Neath
Estuary
The lagoon walls could potentially
alter the flow regime and
hydromorphology in Swansea Bay,
through providing an obstruction
to natural flows and coastal
processes. Further assessment will
be undertaken during the EIA.
Swansea Bay
The construction of the turbine
housing/inlet channel is not considered
likely to have significantly greater
effect on the flow regime and
hydromorphology in Swansea Bay,
than the construction of the lagoon
walls, which are considered separately.
No further assessment required.
Note – Swansea Bay currently failing WFD for phytoplankton
Note – Swansea Bay currently failing WFD for dissolved inorganic nitrogen
Tidal Lagoon Swansea Bay plc
Tidal Lagoon Swansea Bay
Water Framework Directive Screening Page 20
Table 2.4 Preliminary Assessment of components against WFD elements during operation
WFD Elements Lagoon Walls Turbine Housing/ Inlet Channels &
Scour Protection
Biological Quality
Elements
(comprising
phytoplankton,
other aquatic flora
(macrophytes and
phytobenthos),
benthic invertebrate
fauna and fish
fauna)
Swansea Bay, Tawe Estuary, Neath
Estuary
During operation, although not a
barrage across the Neath or Tawe
rivers, the walls would form a
physical barrier to part of the bay
which could impact upon other
aquatic flora and fauna, through
changed flows, reduced feeding
areas and translocation of species.
Further assessment will be
undertaken during the EIA.
Swansea Bay/ Carboniferous Coal
Measures Groundwater
Noise, vibration and re-suspension of
sediment from turbine operation could
potentially impact upon marine
ecology. Although not a barrage there
is a potential for fish to come in
contact with the turbines. Small
change to tidal state within lagoon
footprint could potentially affect
saltwater wedge and groundwater.
Further assessment will be undertaken
during the EIA.
Chemical and
physico-chemical
elements
comprising:
transparency,
thermal conditions,
oxygenation
conditions, salinity,
nutrient conditions,
and specific
pollutants.
Swansea Bay, Tawe Estuary, Neath
Estuary
The presence of the lagoon walls
will alter the flows around the bay.
An assessment of potential change
in water chemistry will be
undertaken in combination with
the turbine operation. Further
assessment will be undertaken
during the EIA.
Swansea Bay
The turbine operation could potentially
cause changes in flows and water
chemistry. This impact will be assessed
in conjunction with the lagoon as a
whole as part of the EIA. Any
additional measures which will be
implemented to improve water quality
within the lagoon during operation will
also be considered. Small change to
tidal state within lagoon footprint
could potentially affect saltwater
wedge and groundwater. Further
assessment will be undertaken during
the EIA.
Hydromorphological
elements
comprising:
morphological
conditions (depth
variation; quantity,
structure and
substrate of the
bed; structure of
the intertidal zone)
and tidal regime
(freshwater flow,
wave exposure).
Swansea Bay, Tawe Estuary, Neath
Estuary
The lagoon walls could potentially
alter the flow regime and
hydromorphology in Swansea Bay,
through providing an obstruction
to existing flows and coastal
processes. Further assessment will
be undertaken during the EIA.
Swansea Bay
The turbine housing will generate
increased currents in its vicinity which
could cause localised scour. Although
localised, it will be considered further
during the EIA. Further assessment will
be undertaken.
Note – Swansea Bay currently failing WFD for phytoplankton
Note – Swansea Bay currently failing WFD for dissolved inorganic nitrogen
2.6.0.4 Those interactions between the Project and the surrounding WFD waterbodies which are
considered to pose a risk to the achievement of the objectives of the WFD in respect of
the relevant waterbody/waterbodies are highlighted in red in Tables 2.3 and 2.4 above.
These components of the Project and interactions will, therefore, be taken forward to
Stage 5, where they are subject to more detailed assessment of their impact upon the
WFD waterbodies.
Tidal Lagoon Swansea Bay plc
Tidal Lagoon Swansea Bay
Water Framework Directive Screening Page 21
2.6.0.5 Stage 5, detailed assessment, will be undertaken during the EIA and reported in the
Environmental Statement submitted with the application for development consent for
the project.
WFD Mitigation Measures Assessment
2.6.0.6 The WFD states that development should not inhibit the achievement of any of the
mitigation measures that could be implemented to enable a waterbody to achieve its
WFD objectives (RBMP Annex B: Water body status objectives). As outlined above, in
Section 2.3.0.5, the Western Wales RBMP includes a series of mitigation measures
relating to Swansea Bay Coastal waterbody. These are not in place, but could be
implemented to ensure that the waterbody achieves its WFD objectives. These mitigation
measures are considered below, in relation to the Project. Where potential conflicts
between the Project and implementation of the RBMP mitigation measures occur, these
are highlighted in red, and where mitigation measures are supported by the proposed
development, these are shown in green. Swansea Bay mitigation measures which are not
affected or are not relevant to the proposed development are shown by strike through:
a) Indirect / offsite mitigation (offsetting measures);
b) Alter timing of dredging / disposal;
c) Reduce sediment resuspension – The Project intends to use dredged material from
Swansea Bay, within the tidal lagoon area, to construct the lagoon walls. During the
construction phase this dredging will cause resuspension of sediment from the seabed
although the geotubes will reduce this compared to normal dredging practices. This
will be further examined during the EIA process;
d) Reduce impact of dredging - The Project intends to use dredged material from
Swansea Bay, within the tidal lagoon area, to construct the lagoon walls – this would
be a temporary, construction phase effect. During operation of the project the effect
on the current dredging practices in Neath, Tawe and Port Talbot channels would be
reviewed as part of the EIA process;
e) Prepare a dredging / disposal strategy - the need for this during the operation phase
would be based on the findings of the EIA;
f) Avoid the need to dredge (e.g. minimise under-keel clearance; use fluid mud
navigation; flow manipulation or training works);
g) Operational and structural changes to locks, sluices, weirs, beach control etc;
h) Preserve and where possible enhance ecological value of marginal aquatic habitat,
banks and riparian zone – will be considered as part of any bank side river works;
i) Managed realignment of flood defence;
j) Bank rehabilitation / reprofiling;
k) Preserve and, where possible, restore historic aquatic habitats – opportunities for
improvements here associated with Port Rock armour intertidal habitat;
l) Removal of hard bank reinforcement or replacement with soft engineering solution –
Lagoon walls are to be rock-armoured, and scour protection is to be employed around
the turbine housing (underwater). The former is therefore extensions of the hard bank
reinforcement. However, it is proposed that there will be some softening of the
existing sea defence rock armour, through the provision of draped dunes etc. which
could result in benefits;
m) Remove obsolete structure - although not obsolete, the removal of the existing 2m
high seawall along the Port eastern breakwater is being considered with it being
replaced with marine landscaping. Although this wall is understood not to be part of
any flood protection, it does provide wave/spray shelter. The offshore lagoon wall and
Tidal Lagoon Swansea Bay plc
Tidal Lagoon Swansea Bay
Water Framework Directive Screening Page 22
reduction in fetch should replace this function, thereby allowing this coastal stretch to
be improved.
2.6.0.7 The potential adverse effect of the proposed development on those mitigation measures
highlighted in red above will be taken forward to Stage 5 for detailed assessment.
Cumulative Impact Assessment
2.6.0.8 The scoping work undertaken for the EIA has identified a list of developments proposed
within the local area that should be reviewed in terms of cumulative effects. These
developments are shown below in Table 2.5, and a preliminary screening has been
undertaken to identify those which will be considered further in terms of the WFD during
the EIA process.
Table 2.5 Preliminary assessment of cumulative sites
Project and location Current Status Preliminary WFD Assessment
Swansea Bay Science and
Innovation Campus, adjacent to
Crymlyn Burrows.
Planning permission granted,
construction Feb 2013 – Sept
2015.
Potential positive impacts in
terms of WFD objective, from a
flood risk perspective, through
encompassing the shoreline
within the tidal lagoon. Further
consideration during EIA. Further
assessment required.
St Modwens land development
- East of port to west of Neath
estuary.
Remediation of land, and
potential future developments
– no details available.
Works anticipated to be
complete – no cumulative impact
anticipated.
Mumbles pier, foreshore and
coastal strip redevelopment
Due to be redeveloped by the
end of 2013.
Works anticipated to be
complete – no cumulative impact
anticipated.
Construction of new RNLI
Lifeboat Station, Mumbles
Expected completion 2014. Works anticipated to be
complete – no cumulative effect
anticipated.
SA1 development Development currently taking
place. Completion date
unknown.
Works shore based – no
cumulative impact anticipated.
Construction of the Southern
Access Road to Coed Darcy
Urban Village, crossing nearby
Crymlyn Bog.
Nearing completion. Works distant and shore based –
no cumulative impact
anticipated.
Swansea Boulevard project-
work between Princess way and
the Strand, and the River Tawe
bridges and The Strand.
First phase to be complete in
November 2013. Second phase
to start 2014 - working to a
similar timescale.
Works shore based – no
cumulative impact anticipated.
Wind turbine - on Welsh water
site on Fabian Way.
Status unknown Works shore based – no
cumulative impact anticipated.
5 wind turbines - at Mynydd
Marchywel between Rhos and
Cilfrew Neath
Submitted Jan 2012.
Consultation finished Jan 2013.
Still in planning.
Works distant – no cumulative
impact anticipated.
16 wind turbines - at Mynydd Y
Gwair, Swansea
Approved – unknown
construction timetable.
Works distant – no cumulative
impact anticipated.
5 wind turbines - on land at
Mynydd Brombil Farm,
Margam, Port Talbot
Submitted June 2012, still in
planning. Consultation finishes
April 2013.
Works distant – no cumulative
effect Works distant and shore
based – no cumulative impact
anticipated.
Atlantic Array Wind Farm – off
North Devon Coast approx
DCO application not submitted.
Construction timetable
Works distant and shore based –
no cumulative impact
Tidal Lagoon Swansea Bay plc
Tidal Lagoon Swansea Bay
Water Framework Directive Screening Page 23
35km distant. unknown. anticipated.
76 turbine Pen y Cymoedd
windfarm near Neath.
Planning approved –
construction 2014
Works distant – no cumulative
impact anticipated.
15 turbine windfarm - on land
500m South West of
Cynnonville Port Talbot
Status Unknown Works distant – no cumulative
impact anticipated.
Port Talbot Harbour
Redevelopment.
Potential future activities/
Development. Status unknown.
Status and need for assessment
will be reviewed in EIA.
Upgrading of existing coastal
defence of Aberavon West
Promenade, Sandfields, Port
Talbot
Status Unknown Increased rock armour. Further
detail sought for EIA and if
available further assessment.
Porthcawl regeneration scheme
Plans include Porthcawl Marina
project.
Approved - Timescale unknown. Works distant– no cumulative
impact anticipated.
Underground coal gasification
under Swansea Bay.
License issued No cumulative impact
anticipated.
Navigational dredging Tawe,
Neath and Port Talbot.
Existing/proposed dredging in
Bristol Channel.
On-going Potential cumulative impacts will
be considered further in the EIA.
Marina dredging - Monkston
cruising and sailing club and
Swansea Marina
On-going Maintenance
dredging
Potential cumulative impacts will
be considered further in the EIA.
Severn Barrage Timescale unknown. High level review to be
undertaken.
Swansea Barrage Operational Currently operational – no
cumulative impacts anticipated.
Cardiff Barrage Operational Project distant and currently
operational – no cumulative
impact anticipated.
Baglan Power station Operational No cumulative impact
anticipated.
2.6.0.9 Those developments that could cumulatively effect the waterbodies and inhibit them
from achieving their WFD objectives are highlighted in red in the above table. A
consideration of those developments will form part of the detailed assessment at Stage 5.
2.7 WFD Detailed Assessment (Stage 5)
2.7.0.1 Those interactions and potential impacts identified for further assessment as part of the
WFD preliminary assessment will be considered during the WFD Detailed Assessment.
This assessment will be undertaken through the EIA process.
Tidal Lagoon Swansea Bay Plc
Tidal Lagoon Swansea Bay
Water Framework Directive Screening
APPENDIX 1
Water Framework Directive Article 4.7
Tidal Lagoon Swansea Bay Plc
Tidal Lagoon Swansea Bay
Water Framework Directive Screening
‘Member States will not be in breach of this Directive when:
- failure to achieve good groundwater status, good ecological status or, where relevant, good
ecological potential or to prevent deterioration in the status of a body of surface water or
groundwater is the result of new modifications to the physical characteristics of a surface water
body or alterations to the level of bodies of groundwater, or
- failure to prevent deterioration from high status to good status of a body of surface water is the
result of new sustainable human development activities and all the following conditions are
met:
(a) all practicable steps are taken to mitigate the adverse impact on the status of the body of
water;
(b) the reasons for those modifications or alterations are specifically set out and explained in
the river basin management plan required under Article 13 and the objectives are reviewed
every six years;
(c) the reasons for those modifications or alterations are of overriding public interest and/or
the benefits to the environment and to society of achieving the objectives set out in
paragraph 1 are outweighed by the benefits of the new modifications or alterations to
human health, to the maintenance of human safety or to sustainable development, and
(d) the beneficial objectives served by those modifications or alterations of the water body
cannot for reasons of technical feasibility or disproportionate cost be achieved by other
means, which are a significantly better environmental option.’