OPW Arterial Drainage · 2020. 4. 21. · Corrib Arterial Drainage Scheme Natura Impact Statement...

Corrib Arterial Drainage Scheme

Natura Impact Statement Page

Arterial Drainage Maintenance Works:

Corrib Arterial Drainage Scheme 2020 - 2024

Natura Impact Statement

January 2020

1 Galway Business Park, Dangan, Galway H91A3EF

173 Ivy Exchange, Granby Place, Parnell Square West, Dublin 1


Natura Impact Statement Page i

Client OPW

Project No. 2514

Project Title Corrib Arterial Drainage Scheme 2020-2024

Report Title Natura Impact Statement

Rev. Status Authors Reviewed By Approved By Issue Date

- DRAFT G. Kilbane S. Gavin D. Bourke 05/12/2019

0 DRAFT G. Kilbane S. Gavin D. Bourke 11/12/2019

1

For Issue: Updated

following OPW

comments

S. Brady S. Gavin D.Bourke 06/01/2020

2

Updated following

additional OPW

comments

S. Brady S. Gavin D.Bourke 08/01/2020


Natura Impact Statement Page ii

Executive Summary

Ryan Hanley has been commissioned by the Office of Public Works (OPW) to provide environmental consultancy

services in relation to statutory arterial drainage maintenance activities activities on the Coirrib Arterial Drainage

Scheme for the period 2020-2024.

Following the methodology outlined in Ryan Hanley (2014a), a screening assessment was conducted to assess

the likely significant effects on European sites of the proposed drainage maintenance activities in the Corrib

Arterial Drainage Scheme in accordance with Article 6(3) of the Habitats Directive (Council Directive 92/43/EEC

on the conservation of natural habitats and of wild fauna and flora). Three “source > pathway > receptor”

chains were examined to assess the likely impact of drainage maintenance activities on European sites; surface

water, land and air, and groundwater pathways. The results of this screening exercise identified that significant

adverse impacts could not be excluded on the following European sites:

▪ Ardkill Turlough SAC (000461)

▪ Ballymaglancy Cave, Cong SAC (000474)

▪ Carrowkeel Turlough SAC (000475)

▪ Cloughmoyne SAC (000479)

▪ Clyard Kettle-Holes SAC (000480)

▪ Connemara Bog Complex SAC (002034)

▪ Galway Bay Complex SAC (000268)

▪ Greaghans Turlough SAC (000503)

▪ Kilglassan/Caheravoostia Turlough Complex SAC (000504)

▪ Levally Lough SAC (000295)

▪ Lisnageeragh Bog and Ballinastack Turlough SAC (000296)

▪ Lough Carra/Mask Complex SAC (001774)

▪ Lough Corrib SAC (000297)

▪ Lough Lurgeen Bog/ Glenamaddy Turlough SAC (000301)

▪ Maumturk Mountains SAC (002008)

▪ Mocorha Lough SAC (001536)

▪ Monivea Bog SAC (002352)

▪ Ross Lake and Woods SAC (001312)

▪ Shrule Turlough SAC (000525)

▪ Towerhill House SAC (002179)

▪ Williamstown Turloughs SAC (002296)

▪ Inner Galway Bay SPA (004031)

▪ Lough Carra SPA (004051)

▪ Lough Corrib SPA (004042)

▪ Lough Mask SPA (004062)

As a result, it was necessary to conduct a Stage 2 Appropriate Assessment to further examine the potential direct

and indirect impacts of the proposed works on the integrity and interest features of the above European sites,

alone and in-combination with other plans and projects, taking into account the site's structure, function and

conservation objectives.

Further examination of the potential sources of impact on the European sites above, looking at surface water,

land and air and groundwater pathways, was conducted. Where potentially significant adverse impacts were

identified, a range of mitigation and avoidance measures have been stipulated to help offset them.


Natura Impact Statement Page iii

As a result of this Appropriate Assessment it has been concluded, that given the avoidance and mitigation

measures suggested, the proposed drainage maintenance operations in the Corrib Arterial Drainage Scheme

2020 – 2024 will not have a significant adverse impact on the above European sites.



Contents Executive Summary ................................................................................................ ii

1 Introduction ................................................................................................. 1

1.1 Background ........................................................................................................ 1

1.2 Legislative Context............................................................................................. 1

1.3 Appropriate Assessment Process ...................................................................... 1

2 Arterial Drainage Maintenance ................................................................... 5

2.1 Background ........................................................................................................ 5

2.2 Drainage Maintenance Activities ....................................................................... 5

2.3 The Corrib Arterial Drainage Scheme.............................................................. 12

2.4 Drainage Maintenance Works Proposed for the Corrib Arterial Drainage

Scheme....................................................................................................................... 13

3 Screening Assessment Results ............................................................... 16

3.1 Introduction ...................................................................................................... 16

3.2 Screening Assessment Conclusions ............................................................... 25

4 European Sites within the Zone of Influence of Drainage Maintenance

Activities .................................................................................................... 30

4.1 Introduction ...................................................................................................... 30

4.2 Ardkill Turlough SAC (000461) ........................................................................ 30

4.3 Ballymaglancy Cave, Cong SAC (000474) ...................................................... 32

4.4 Carrowkeel Turlough SAC (000475)................................................................ 32

4.5 Cloughmoyne SAC (000479) ........................................................................... 33

4.6 Clyard Kettle-Holes SAC (000480) .................................................................. 34

4.7 Connemara Bog Complex SAC (002034) ....................................................... 36

4.8 Galway Bay Complex SAC (000268)............................................................... 40

4.9 Greaghans Turlough SAC (000503) ................................................................ 44

4.10 Kilglassan/Caheravoostia Turlough Complex SAC (000504) ...................... 46

4.11 Levally Lough SAC (000295) ....................................................................... 47

4.12 Lisnageeragh Bog and Ballinastack Turlough SAC (000296) ..................... 48

4.13 Lough Carra/Mask Complex SAC (001774) ................................................ 49

4.14 Lough Corrib SAC (000297) ........................................................................ 52

4.15 Lough Lurgeen Bog/ Glenamaddy Turlough SAC (000301) ....................... 57

4.16 Maumturk Mountains SAC (002008) ........................................................... 59

4.17 Mocorha Lough SAC (001536) .................................................................... 62

4.18 Monivea Bog SAC (002352) ........................................................................ 63

4.19 Ross Lake and Woods SAC (001312) ......................................................... 64

4.20 Shrule Turlough SAC (000525) ................................................................... 65



4.21 Towerhill House SAC (002179) ................................................................... 66

4.22 Williamstown Turloughs SAC (002296) ....................................................... 67

4.23 Inner Galway Bay SPA (004031) ................................................................. 68

4.24 Lough Carra SPA (004051) ......................................................................... 70

4.25 Lough Corrib SPA (004042) ........................................................................ 71

4.26 Lough Mask SPA (004062) .......................................................................... 72

4.27 Description of the receiving environment - Ecological Walkover Survey

Results 74

5 Appropriate Assessment .......................................................................... 91

5.1 Introduction ...................................................................................................... 91

5.2 Identification of Potential Sources of Impact ................................................... 91

5.3 Impact Assessment........................................................................................ 108

6 Avoidance and Mitigation Measures ...................................................... 163

6.1 Introduction .................................................................................................... 163

6.2 Mitigation for Other Ecological Receptors ..................................................... 165

6.3 Mitigation for Bridge/Structure Maintenance Works ...................................... 167

7 Conclusions ............................................................................................. 168

Appendix A ...............................................................................................................

Corrib 2020 – 2024 Maintenance Programme.................................................................... i

Appendix B ...............................................................................................................

Maps of Annexed Habitats Recorded during the 2019 Ecological Survey.................... ii


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List of Figures

Figure 1-1: The Appropriate Assessment Process (from: Appropriate Assessment of Plans and

Projects in Ireland - Guidance for Planning Authorities, DEHLG, 2009) ................................... 2

Figure 1-2: Screening assessment process .............................................................................. 3

Figure 2-1: Plane Bed to Low Gradient Channels in Corrib Arterial Drainage Scheme ........... 7

Figure 2-2: Medium to High Gradient Channels in the Corrib Arterial Drainage scheme ........ 7

Figure 2-3: Map of the Corrib Scheme as identified in the AA Screening Report (2014) ........ 13

Figure 3-1: Channels and embankments with potential impacts via surface water pathways -

North West Corrib as identified in the AA Screening Report (2014) ....................................... 17


North East Corrib as identified in the AA Screening Report (2014) ........................................ 17


South West Corrib as identified in the AA Screening Report (2014) ....................................... 18


South East Corrib as identified in the AA Screening Report (2014) ........................................ 18

Figure 3-5: Channels and embankments with potential impacts via land and air pathways -








Figure 3-9: Channels and embankments with potential impacts via groundwater pathways -








Figure 3-13: Map of all channels, embankments and structures where significant likely effects

may arise - Corrib NW as identified in the AA Screening Report (2014) ................................ 28


may arise - Corrib NE as identified in the AA Screening Report (2014) ................................. 29


may arise - Corrib SW as identified in the AA Screening Report (2014) ................................. 29


may arise - Corrib SE as identified in the AA Screening Report (2014) .................................. 30

Figure 4-1: Sample Habitat Map ............................................................................................ 82


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List of Tables

Table 2-1 OPW Drainage Maintenance Subcategories ............................................................. 5

Table 2-2 OPW Drainage Maintenance Types .......................................................................... 5

Table 2-3 Channels excluded from drainage maintenance ..................................................... 14

Table 3-1Screening Assessment Conclusions ........................................................................ 25

Table 4-1 Qualifying Interests of Ardkill Turlough SAC (000461) ............................................ 31

Table 4-2 Qualifying Interests of Ballymaglancy Cave, Cong SAC (000474) ......................... 32

Table 4-3 Qualifying Interests of Carrowkeel Turlough SAC (000475) ................................... 33

Table 4-4 Qualifying Interests of Cloughmoyne SAC (000479)............................................... 34

Table 4-5 Qualifying Interests of Clyard Kettle-Holes SAC (000480) ...................................... 35

Table 4-6 Qualifying Interests of Connemara Bog Complex SAC (002034) ........................... 36

Table 4-7 Qualifying Interests of Galway Bay Complex SAC (000268) .................................. 41

Table 4-8 Qualifying Interests of Greaghans Turlough SAC (000503) .................................... 45

Table 4-9 Qualifying Interests of Kilglassan/Caheravoostia Turlough Complex SAC (000504)

................................................................................................................................................. 46

Table 4-10 Qualifying Interests of Levally Lough SAC (000295) ............................................ 47

Table 4-11 Qualifying Interests of Lisnageeragh Bog and Ballinastack Turlough SAC (000296)

................................................................................................................................................. 48

Table 4-12 Qualifying Interests of Lough Carra/Mask Complex SAC (001774) ...................... 50

Table 4-13 Qualifying Interests of Lough Corrib SAC (000297) .............................................. 53

Table 4-14 Qualifying Interests of Lough Lurgeen Bog/ Glenamaddy Turlough SAC (000301)

................................................................................................................................................. 58

Table 4-15 Qualifying Interests of Maumturk Mountains SAC (002008) ................................. 60

Table 4-16 Qualifying Interests of Mocorha Lough SAC (001536) .......................................... 62

Table 4-17 Qualifying Interests of Monivea Bog SAC (002352) .............................................. 63

Table 4-18 Qualifying Interests of Ross Lake and Woods SAC (001312) .............................. 64

Table 4-19 Qualifying Interests of Shrule Turlough SAC (000525) ......................................... 66

Table 4-20 Qualifying Interests of Towerhill House SAC (002179) ......................................... 67

Table 4-21 Qualifying Interests of Williamstown Turloughs SAC (002296) ............................. 68

Table 4-22 Qualifying Interests of Inner Galway Bay SPA (004031) ...................................... 69

Table 4-23 Qualifying Interests of Lough Carra SPA (004051) ............................................... 70

Table 4-24 Qualifying Interests of Lough Corrib SPA (004042) .............................................. 71

Table 4-25 Qualifying Interests of Lough Mask SPA (004062) ............................................... 73

Table 4-26 Habitats identified within the Corrib catchment ..................................................... 74

Table 4-27 Annex I Habitats within Corrib Arterial Drainage Scheme ..................................... 82

Table 4-28 Bird Species Recorded in Corrib Clare Arterial Drainage Scheme ....................... 87


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Table 4-29 Bird Species Recorded in Corrib Headford Arterial Drainage Scheme ................. 89

Table 4-30 Bird Species Recorded in Corrib Mask Arterial Drainage Scheme ....................... 90

Table 5-1Qualifying Interests/Special Conservation Interests on screened in European sites

likely to be impacted upon via surface water ........................................................................... 91

Table 5-2 Potential Sources of Impact via Surface Water Pathways ...................................... 96

Table 5-3 Qualifying Interests/Special Conservation Interests on screened in European sites

likely to be impacted upon via land and air pathways ............................................................. 97

Table 5-4 Potential Sources of Impact via Land and Air Pathways ....................................... 102

Table 5-5 Qualifying Interests/Special Conservation Interests on screened in European sites

likely to be impacted upon via groundwater pathways .......................................................... 102

Table 5-6 Potential Sources of Impact via Groundwater Pathways ...................................... 107

Table 5-7 Impact Prediction - Ardkill Turlough SAC (000461) ............................................... 111

Table 5-8 Impact Prediction - Ballymaglancy Cave, Cong SAC 000474) ............................. 112

Table 5-9 Impact Prediction - Carrowkeel Turlough SAC (000475) ...................................... 113

Table 5-10 Impact Prediction - Cloughmoyne SAC (000479) ............................................... 114

Table 5-11 Impact Prediction - Clyard Kettle-Holes SAC (000480) ...................................... 115

Table 5-12 Impact Prediction - Connemara Bog Complex SAC (002034) ............................ 117

Table 5-13 Impact Prediction - Galway Bay Complex SAC (000268) ................................... 120

Table 5-14 Impact Prediction - Greaghans Turlough SAC (000503) .................................... 123

Table 5-15 Impact Prediction Kilglassan/ Caheravoostia Turlough Complex SAC (000504) 124

Table 5-16 Impact Prediction Levally Lough SAC (000295) .................................................. 125

Table 5-17 Impact Prediction Lisnageeragh Bog and Ballinastack Turlough SAC (000296) 127

Table 5-18 Impact Prediction - Lough Carra/ Mask Complex SAC (001774) ........................ 129

Table 5-19 Impact Prediction - Lough Corrib SAC (000297) ................................................. 133

Table 5-20 Impact Prediction - Lough Lurgeen Bog/ Glenamaddy Turlough SAC (000301) 139

Table 5-21.Impact Prediction - Maumturk Mountains SAC (002008) .................................... 142

Table 5-22 Mocorha Lough SAC (001536) ............................................................................ 145

Table 5-23 Monivea Bog SAC (002352) ................................................................................ 146

Table 5-24 Ross Lake and Woods SAC (001312) ................................................................ 148

Table 5-25 Impact Prediction Shrule Turlough SAC (000525) .............................................. 150

Table 5-26 Impact Prediction Towerhill House SAC (002179) .............................................. 152

Table 5-27 Impact Prediction Williamstown Turloughs SAC (002296) .................................. 153

Table 5-28 Impact Prediction Inner Galway Bay SPA (004031)............................................ 154

Table 5-29 Impact Prediction - Lough Carra SPA (004051) .................................................. 156

Table 5-30Table 5 30 Impact Prediction - Lough Corrib SPA (004042) ................................ 158

Table 5-31 Impact Prediction - Lough Mask SPA (004062) .................................................. 161


Natura Impact Statement Page vii

Abbreviations

COSD ----------------------------------Conservation Objective Supporting Document

DEHLG ----------------------------------Department of Environment, Heritage and Local Government

EPA ----------------------------------Environmental Protection Agency

GIS ----------------------------------Geographical Information System

GWB ----------------------------------Groundwater Body

GWD ----------------------------------Groundwater Dependent

IFI ----------------------------------Inland Fisheries Ireland

IROPI --------------------------------- Imperative Reason of Overriding Public Interest

NHA --------------------------------- Natural Heritage Area

NPWS ----------------------------------National Parks and Wildlife Service

OPW ----------------------------------Office of Public Works

SAC ----------------------------------Special Area of Conservation

SPA ----------------------------------Special Protection Area

SWD ----------------------------------Surface Water Dependent

WFD ----------------------------------Water Framework Directive


Natura Impact Statement Page 1

1 Introduction

1.1 Background

Ryan Hanley has been commissioned by the Office of Public Works (OPW) to provide environmental consultancy

services in relation to statutory arterial drainage maintenance activities that will take place over the five-year

period 2020-2024.

This Natura Impact Statement (NIS) provides the results of the Appropriate Assessment conducted for the Corrib

Arterial Drainage Scheme in accordance with Article 6(3) of the Habitats Directive (Council Directive 92/43/EEC

on the conservation of natural habitats and of wild fauna and flora). A screening assessment was conducted in

2014 for the Corrib Arterial Drainage Scheme (JBA Consulting, 2014a). It determined that significant adverse

effects on European sites are likely within the zone of influence of the proposed arterial drainage maintenance

activities. The maintenance activities involved in the 2020- 2024 scheme are of a similar nature and so an

additional screening is unnecessary and so it moves directly to Stage 2.

1.2 Legislative Context

The Habitats Directive (Council Directive 92/43/EEC on the conservation of natural habitats and of wild fauna

and flora) aims to maintain or restore the favourable conservation status of habitats and species of community

interest across Europe. The requirements of this Directive are transposed into Irish law through the European

Communities (Birds and Natural Habitats) Regulations) 2011 (S.I. No. 477 of 2011).

Under the Directive a network of sites of nature conservation importance have been identified by each Member

State as containing specified habitats or species requiring to be maintained or returned to favourable

conservation status. In Ireland the network consists of Special Areas of Conservation (SACs) and Special Protection

Areas (SPAs), and also candidate sites, which form the Natura 2000 network.

Article 6(3) of the Habitats Directive requires that, in relation to European designated sites (i.e. SACs and SPAs

that form the Natura 2000 network), "any plan or project not directly connected with or necessary to the

management of the site but likely to have a significant effect thereon, either individually or in combination with

other plans or projects, shall be subject to appropriate assessment of its implications for the site in view of the site's

conservation objectives". A competent authority (e.g. the OPW or Local Authority) can only agree to a plan or

project after having determined that it will not adversely affect the integrity of the site concerned.

Under article 6(4) of the Directive, if adverse impacts are likely, and in the absence of alternative options, a

plan or project must nevertheless proceed for imperative reasons of overriding public interest (IROPI), including

social or economic reasons, a Member State is required to take all compensatory measures necessary to ensure

the overall integrity of the European site. The European Commission have to be informed of any compensatory

measures adopted, unless a priority habitat type or species is present and in which case an opinion from the

European Commission is required beforehand (unless for human health or public safety reasons, or of benefit to

the environment).

1.3 Appropriate Assessment Process

Guidance on the Appropriate Assessment (AA) process was produced by the European Commission in 2002,

which was subsequently developed into guidance specifically for Ireland by the Department of Environment,

Heritage and Local Government (DEHLG) (2009). These guidance documents identify a staged approach to

conducting an AA, as shown Figure 1-1.



Figure 1-1: The Appropriate Assessment Process (from: Appropriate Assessment of Plans and Projects in Ireland -

Guidance for Planning Authorities, DEHLG, 2009)

1.3.1 Stage 1 - Screening for AA

The initial, screening stage of the Appropriate Assessment is to determine:

a) whether the proposed plan or project is directly connected with or necessary for the management of the

European designated site for nature conservation

b) if it is likely to have a significant adverse effect on the European designated site, either individually or

in combination with other plans or projects

For those sites where potential adverse impacts are identified, either alone or in combination with other plans or

projects, further assessment is necessary to determine if the proposals will have an adverse impact on the integrity

of a European designated site, in view of the site’s conservation objectives (i.e. the process proceeds to Stage 2).

1.3.2 Stage 2 - AA

This stage requires a more in-depth evaluation of the plan or project, and the potential direct and indirect impacts

of them on the integrity and interest features of the European designated site(s), alone and in-combination with

other plans and projects, taking into account the site's structure, function and conservation objectives. Where

required, mitigation or avoidance measures will be suggested.

The competent authority can only agree to the plan or project after having ascertained that it will not adversely

affect the integrity of the site(s) concerned. If this cannot be determined, and where mitigation cannot be

achieved, then alternative solutions will need to be considered (i.e. the process proceeds to Stage 3).

1.3.3 Stage 3 - Alternative Solutions

Where adverse impacts on the integrity of European sites are identified, and mitigation cannot be satisfactorily

implemented, alternative ways of achieving the objectives of the plan or project that avoid adverse impacts

need to be considered. If none can be found, the process proceeds to Stage 4.

1.3.4 Stage 4 - IROPI

Where adverse impacts of a plan or project on the integrity of European sites are identified and no alternative

solutions exist, the plan will only be allowed to progress if imperative reasons of overriding public interest (IROPI)

can be demonstrated. In this case compensatory measures will be required.

The process only proceeds through each of the four stages for certain plans or projects. For example, for a plan

or project, not connected with management of a site, but where no likely significant impacts are identified, the

process stops at stage 1. Throughout the process, the precautionary principle must be applied, so that any

uncertainties do not result in adverse impacts on a site.

1.4 Methodology

This NIS has been prepared with regard to the following documents:

▪ Department of Environment, Heritage and Local Government (2009) Appropriate Assessment

of Plans and Projects in Ireland - Guidance for Planning Authorities

Stage 1

Screening for AA

Stage 2

AA

Stage 4

IROPI

Stage 3

Alternative Solutions



▪ Ryan Hanley (2014a) Office of Public Works Arterial Drainage Maintenance Environmental

Services 2013. Stage 1: Appropriate Assessment Screening Methodology for the Maintenance

of Arterial Drainage Schemes. Methodology. Unpublished Report.

▪ Ryan Hanley (2014c) Office of Public Works Arterial Drainage Maintenance Service 2014-

2018. Source > Pathway > Receptor Chains for Appropriate Assessment. Unpublished Report.

▪ National Parks and Wildlife Service (NPWS) Site synopsis, European data forms and

Conservation Objectives

1.4.1 Screening

The screening assessment conducted for these works has been undertaken in line with recommended guidance

including that specifically produced for the OPW in 2014 (Ryan Hanley 2014b, 2014a). This methodology is

based on source > pathway > receptor chain principles and involves assessing likely significant effects on Natura

2000 sites within the zone of influence of the proposed drainage maintenance in relation to three pathways:

1. Surface water

2. Land & air

3. Groundwater

The screening assessment involves assessing the impacts of drainage maintenance operations within the arterial

drainage scheme, and its zone of influence, in relation to each of the three pathways individually. The results of

each pathway are then combined in a concluding section to identify if/where likely significant effects may arise.

Figure 1-2: Screening assessment process

The screening process (Figure 1-2) uses a combination of GIS analysis and qualitative assessment to identify

which drainage maintenance activities, on which specific watercourses, are likely to have significant effects on



the integrity of European Site. The screening report, conducted by JBA ecologists in 2014, has been reviewed

and updated as necessary for the production of this NIS.

1.4.2 Ecological Walkover Surveys

To further inform the Appropriate Assessment process, the OPW selected a number of channels within the Corrib

Arterial Drainage Scheme for assessment through the undertaking of an ecological walkover survey. The selected

channels are those located in, or within 100m of, a European site.

The ecological walkover survey was carried out in general accordance with the methods outlined in the following

documents:

▪ Heritage Council (2011). Best Practice Guidance for Habitat Survey and Mapping (Smith et al. 2011).

▪ Ecological Surveying Techniques for Protected Flora and Fauna during the Planning of National Road

Schemes (NRA 2009).

▪ Fossitt, J. (2000). A Guide to Habitats in Ireland. The Heritage Council, Kilkenny (Fossitt 2000).

Habitats have been named and described following Fossitt (2000). Nomenclature for higher plants principally

follows that given in Webb’s An Irish Flora (Parnell and Curtis, 2012).

Aerial photographs and site maps assisted the habitat survey. Protected species, including mammals (e.g. Otter,

Badger) and birds, were surveyed based upon sightings and signs of activity during the habitat survey and also

by the identification of potentially suitable habitats. This included a preliminary assessment of features with

suitability for roosting bats and recording of any non-native invasive species found. All evidence of protected

habitats and species was recorded using QField (QGIS), and all information gathered was provided to the OPW

on a GIS database. The results of these surveys have informed this NIS where relevant.

1.4.3 Consultation

To further enhance understanding of the baseline of the scheme area, consultation has been undertaken with local

representatives from Inland Fisheries Ireland (IFI) and the National Parks and Wildlife Service (NPWS). Local

OPW officers were also contacted for further ecological information.

This report has been produced on currently available information, with the most up-to-date versions used.

Where new, or updated, information becomes available the OPW will consider and review the findings of this

assessment, if necessary. The findings of this assessment will be subject to consultation with the NPWS and IFI.



2 Arterial Drainage Maintenance

2.1 Background

Between 1945 and 1995, under the Arterial Drainage Act (1945), the OPW completed 34 Arterial Drainage

Schemes on river catchments, along with five estuarine embankment schemes (over 11,500km of channel and

730km of embankments). The OPW is statutorily obligated to maintain arterial drainage channels under the

1945 Arterial Drainage Act, and since their completion, maintenance of these Arterial Drainage Schemes has

been ongoing, with the majority of channels maintained every five years. However, larger channels tend to be

only maintained every ten years, on average.

2.2 Drainage Maintenance Activities

Arterial Drainage Maintenance includes a range of operations such as silt and vegetation management, mowing

and structure maintenance, as detailed in Table 2-1below (See also OPW (2019) Environmental Guidance EP1,

Table 1.3 and 1.4), and listed as channel, embankment or structure maintenance in Table 2-2 below. It is required

to retain the arterial drainage scheme design capacity.

Table 2-1 OPW Drainage Maintenance Subcategories

Drainage Maintenance Subcategories

A Silt and vegetation management

B Aquatic vegetation cutting

C Bank protection

D Bush cutting/Branch trimming

E Tree cutting

F Other Mulching embankment

Mowing embankment

Gate installation

Sluice maintenance

Bridge maintenance

Spraying with herbicide

Table 2-2 OPW Drainage Maintenance Types

Category Maintenance Type Code

Channel Maintenance

Silt and vegetation management A

Aquatic vegetation cutting B

Bank protection C

Bush cutting/Branch trimming D

Tree cutting E

Other F

Embankment Maintenance


Tree cutting E

Mulching F

Mowing F

Gate installation F

Structural Maintenance

Sluice maintenance F

Bridge maintenance F

Bank protection C


Tree cutting E



The following sections provide further details on the types and nature of arterial drainage maintenance

operations undertaken by the OPW.

2.2.1 Channel Maintenance Activities

The majority of drainage maintenance activities are focused on channel maintenance. While the frequency of

maintenance on an individual channel may vary, with some channels requiring maintenance annually and others

only requiring maintenance every twenty years, the average channel requires maintenance every four to six

years. In this regard, approximately 2,000km of channels are maintained annually and nearly all of the

11,500km of channels across Irelands Arterial Drainage Schemes will have been maintained at least once over

a period of five years. Channel maintenance is organised on a regional basis, with OPW Arterial Drainage

Maintenance Regional Offices in Limerick, Headford, Co. Galway and Trim, Co. Meath.

Scheme Design Standards

Arterial Drainage Schemes constructed under the Arterial Drainage Act, 1945 were designed to provide an

outfall for drainage of agricultural lands, and generally provided protection for a 3-year flood event. Where

the creation of an outfall dictated the design bed levels, greater protection than the 3-year flood event was

achieved as a consequence. In the case of modern flood relief schemes, flood protection for a 100-year flood

event would be the design objective.

The original Scheme designs including the outfall datum for each of the Arterial Drainage Schemes are available

in the relevant OPW Arterial Drainage Maintenance Regional Office. This includes the mapped Scheme design,

and the associated long sections and cross sections. These designs are used to inform channel maintenance.

Types of Channel Requiring Maintenance

In the years following the construction of a drainage scheme there is a tendency for the channel capacity to be

progressively reduced due mainly to the transportation and deposition of bed materials, the accumulation of silt

and the growth of in-channel vegetation. The resultant channel maintenance consists of repetitive works of a

cyclical nature, to restore the Schemes design levels i.e. outfall datum in order to maintain the channel's designed

capacity to convey water.

Channels are prioritised for maintenance based on the rate of deterioration and the risk arising. The selection

takes account of requests from the general public and potential flooding risk to roads, properties, urban areas

WTP’s and WWTP’s (OPW, 2019).

Plane Bed to Low Gradient Channels

Some 60 – 70% of maintained channels are of gentle longitudinal gradient and subject to relatively rapid

deposition of silt, especially those that are subject to prolific growth of in-channel vegetation. The majority of

maintenance works are therefore located on smaller lower-lying channels, with 90% of works in channels with a

base width of <3m (OPW, 2011a). In such channels silt and inchannel vegetation may cause the low flow level

to rise by 50-300mm above the Scheme design level. In such circumstances, maintenance is focused on restoring

both low-flow and flood-flow water levels to original Scheme design.



Figure 2-1: Plane Bed to Low Gradient Channels in Corrib Arterial Drainage Scheme

Medium to High Gradient Channels

A smaller proportion of channels are steep and fast flowing and are subject to flash floods, bank erosion and

rapid movement of bed gravel. The steeper sections of channel normally require relatively little and infrequent

maintenance works as opposed to channels of low gradient which are subject to rapid accumulation of silt and

proliferation of vegetation. These channels will have a greater requirement for bank protection works.

Figure 2-2: Medium to High Gradient Channels in the Corrib Arterial Drainage scheme

Periods and Cycles of Maintenance

The average channel requires silt and vegetation management every four to six years. However, channels with

prolific weed growth may require maintenance annually, particularly where downstream bridges are at risk of

being blocked due to a flow of decaying vegetation in autumn. Conversely, some channels may only require in-

stream maintenance every twenty years due to the self-cleaning characteristics e.g. high gradient channels.

Where the period between previous channel maintenance works has been exceptionally long, dense scrub and

woody vegetation can establish along the channel and within the maintenance access corridor. In such

circumstances, drainage maintenance works will include the removal of scrub/transitional woodland (WS1) that

has developed along the banksides via bush cutting/branch trimming, tree cutting or mulching. This is undertaken

between the 1st September and 28th February to avoid the residential bird nesting season (from the 1st March

to 31st August as per the Wildlife Act (1976).

In contrast, in-stream works for silt and vegetation management are carried out outside of the salmonid spawning

season (May to September) and the times that early life stages of salmonid fish will be present as per Section

173 of the Fisheries (Consolidation) Act (1959) on channels with salmonid spawning habitat. Any works required



during this period are carried out in consultation with IFI. As a result, there may be a two-stage approach to the

works, with silt and in-stream vegetation management carried out during the open season (i.e. summer months),

while woody vegetation removal is carried out in the winter months.

Other restrictions on works may also apply in relation to the presence/absence of other protected species such

as White-clawed Crayfish and Sea, River and Brook Lamprey which will influence the timing of works.

2.2.2 Embankment Maintenance Activities

Scheme Design Standards

As above for the Arterial Drainage Schemes, Estuarine Embankment Schemes constructed under the Arterial

Drainage Act 1945 were designed to provide an outfall for drainage of agricultural lands, and generally

provided protection for a 3-year flood event. Where the creation of an outfall dictated the design bed levels,

greater protection than the 3-year flood event was achieved as a consequence. In the case of modern flood

relief schemes, flood protection for a 100-year flood event would be the design objective.

The original Scheme designs are available in the relevant OPW Arterial Drainage Maintenance Regional Office.

This includes the mapped Scheme design, and the associated long sections and cross sections.

Types of Embankments Requiring Maintenance

All embankments and associated sluice structures (see section 2.2.3) are inspected annually for signs of disrepair.

Regular inspections are carried out on sections of embankments, which are known from experience to be at risk,

together with additional inspections after a storm surge at sea or a high tidal/flood event. Maintenance of

embankments includes removal of vegetation to allow for inspection of the embankment, and in some cases the

replacement of existing fencing with gates to allow for future access during maintenance.

2.2.3 Structural Maintenance Activities

Structural Design Standards

During the construction of the Arterial Drainage Schemes under the 1945 Act, some 18,500 No. accommodation

bridges were identified and modified, or replaced as required. These bridges provide farmers owning land on

both sides of a channels with farm vehicular and/or foot access from one side to the other. The type of bridge

provided depended on the width, depth and required flow capacity of the channel, and ranged from concrete

piped culverts to relatively large structures formed on concrete or masonry abutments spanned by structural steel

beams, or lattice girders together with concrete or timber decking.

During the Estuarine Embankment Schemes under the 1945 Act, existing sluice structures were identified and

modified, or replaced as required. Additional sluice structures were constructed as required bringing the total

number to approximately 750. The function of these sluice structures is to allow water from the floodplain behind

the embankments to discharge to the main river or estuary.

Types of Structures Requiring Maintenance

In general, as channel maintenance proceeds, the bridges are examined by the supervisory industrial staff and

if required, repairs/replacements are scheduled. The type of bridge structures, which are most likely to have

fallen into a critical state of disrepair, are those with timber decking supported on steel beams, and those in

which abutment foundations are being undercut. There is a standard type of design for the replacement of these

structures, which consists essentially of mass concrete abutments with reinforced cast in-situ decking. This type of

structure is simple to construct and under normal circumstances, it will last for many years with little or no

maintenance. Pre-cast concrete elements are also used in some instances for repair of structures.



On many occasions, it is not necessary to totally replace a bridge, and repairs such as underpinning the

foundation or replacement of wing-walls, parapets or sections of the deck may be all that is required to extend

the useful life of the structure. Where bridge maintenance may be required, a Bridge Inspection Form will be

filled out by the Foreman, prior to the works. This will determine the need for further assessment and potentially,

any mitigation measures that may be required. See EP4 of the OPW (2019 Environmental Guidance.

All embankments and associated structures are inspected annually for disrepair. Due to the time elapsed since

scheme completion, some of these sluice structures have reached their design life and have started to fail. In this

instance, full replacement is required. Typically, this involves the installation of pre-cast headwalls and back

walls, and the replacement of existing corrugated galvanised steel pipes with PVC plastic pipes.

Sluice doors are the most frequent part of the sluice structure that are required to be repaired or replaced.

Repairs to a sluice door consist of replacing the arms/hinges on the existing cast iron door. On occasion, the

existing cast iron door would be replaced with a high-density polyethylene (HDPE) door. Blockages often occur

at the doors of the sluices due to silt build up. These blockages are removed using along reach excavator working

from the bank of the channel.

It is not known where bridges, sluice doors or structures may require maintenance on the Corrib Scheme.

Maintenance of bridges, structures and/or sluices will only occur within the scheme after following the relevant

environmental procedures as detailed in the OPW Environmental Procedures (OPW, 2019) and using specific

mitigation measures as defined in this document. This NIS does not include assessment for the removal, demolition,

replacement or erection of bridges, sluices or structures

2.2.4 Maintenance works considered outside of the Scheme Design Standards and outside of normal

Arterial Drainage Maintenance Works

Occasionally, works are required that can be considered outside of the scope of the normal Arterial Drainage

Maintenance Works to maintain a scheme. Works considered outside of the normal scope of statutory arterial

drainage maintenance works are not assessed for impacts in this report. Works that could be considered outside

of the normal scope of works include those involving extensive bank protection measures, removal of mature

woodland or unplanned bridge replacement works that has not had any assessments which are within the zone

of influence of a European site.

2.2.5 Plant and Machinery

The types of machinery typically utilised during maintenance works would include 3600 hydraulic excavators

(from 15-20 tonne excavators), mini-diggers, tractors and trailers, tipper lorries, hydraulic shears, weed cutting

equipment, chainsaws, mulchers and mowers; the machinery used is dependent on the maintenance activity being

conducted.

The removal of dense in-stream silt and vegetation requires the use of a hydraulic excavator with a 1.5m wide

(approximate) bucket (capacity approximate 500ltrs). For standard excavators, works progress at a rate of

700m to 900m per week. In relation to long-reach excavators, works progress at a slower rate of between

200m and 350m per week. Rates may change due to channel width or ground conditions.

2.2.6 Maintenance Access Corridors (MAC) and Working Zone

Maintenance sites are generally accessed via the public road and through farmland. A maintenance access

corridor is utilised along one side of a channel for maintenance purposes. These established routes are used to

track the hydraulic excavators for maintenance and for the disposal of spoil (see section 2.2.7). The same route

is generally followed every maintenance cycle. This approach avoids disturbance of habitats on the opposite

bank during works.



Where grasslands are present within the maintenance access corridor, the impact is predominantly temporary as

the grasslands are trampled by machinery and can recolonise following completion of the maintenance activities.

Within woodland and scrub habitats a linear path more typical of disturbed vegetation i.e. scrub/transitional

woodland (WS1) will be evident along the maintenance access corridor due to regular machine access. In this

regard, the disturbance regime associated with the tracking of plant machinery along the maintenance access

corridors on the channel bank arrests succession to mature woodland such that scrub/transitional woodland (WS1)

dominates. Where mature trees are present these are generally avoided by plant machinery.

Structures are generally accessed through farmland from the public road above. Plant machinery will utilise the

same maintenance access corridor used for channel maintenance to gain access to the structure. Where individual

trees, woodland and scrub habitats are present at the location of the structure, these may be removed to facilitate

bridge inspection and works. Where mature trees are present these are generally avoided by plant machinery.

The location of mobile short-term staff welfare facilities, plant storage and car parking agreed with local

landowners. There is no requirement for temporary site lighting.

There is a requirement for water supply and disposal of wastewater from the welfare facilities (see section 2.2.8

in relation to waste disposal).

2.2.7 Site Compounds (Welfare Facilities), Access Routes and Haul Roads

Haul roads are generally not required to facilitate drainage maintenance activities. Where access is required in

soft ground conditions, plant equipment will be brought in on tracks or temporary matting will be laid to provide

a corridor for machinery access. Where matting is utilised, it will be completely removed post completion of

works to allow vegetation to recolonise. All plant and machinery are confined to one defined access route to

minimise disturbance.

All plant and machinery are regularly maintained and serviced to minimise release of hydrocarbons. All hydraulic

excavators and other plant machinery use long life engine oil and biodegradable hydraulic oil. Fuelling and

lubrication are conducted a minimum of 50m away from all channels. Spill kits are present in all plant used in

maintenance activities. Integrated submersible pumps are also deployed in the event of structural maintenance

and the requirement for dewatering of excavations.

2.2.8 Waste Output/Disposal

The material removed from a channel during silt and vegetation management is normally spread thinly along the

bank or on top of existing spoil heaps where present within the access corridor. All dead wood material is left

on site to decompose or is removed off site and utilised as firewood under local landowner agreements. Where

mulchers or mowers are deployed, the arisings are left on site to decompose or the mulched material is buried.

Construction and demolition waste from structures includes broken concrete and stone. Steel railings are returned

to the depot for recycling. Used engine oil and hydraulic oil is disposed of by a licensed waste handler. Toilet

facilities are maintained by a licensed waste handler. Any waste generated on site is returned to the depot for

segregation and disposal by a licensed waste handler.

2.2.9 Working Hours

All maintenance activities are undertaken during daylight hours. Standard working hours are 8.00am to 4.30pm,

with lunch and tea breaks, Monday to Friday. There is no requirement for temporary site lighting to facilitate

works. Machines are powered down when not in use.



2.2.10 Environmental Training

Environmental training of all staff involved in drainage maintenance is an ongoing process through site visits and

audits. A useful forum for knowledge sharing is the Foreman’s meeting which is typically held annually, although

some years have been skipped. This meeting between IFI, the OPW’s environment section, and the on-site

foremen presents new information and allows for discussion on environmental issues.

Technical and Operational Staff have completed formal training in Environmental Drainage Maintenance (EDM)

in 2004. This training course was revised and expanded under the OPW’s Environmental River Enhancement

Programme (EREP) and was delivered to all staff in 2010. The training programme delivered included

presentations in river corridor ecology, the Environmental Drainage Maintenance Guidance Notes (Ten Steps to

Environmentally Friendly Maintenance), maintenance strategies involving both ‘enhanced maintenance’ and

‘capital enhancement’, and OPW’s Environmental Management Protocols and Standard Operating Procedures

(EPs) (see section 2.2.12 for more details). Both sets of training were developed and delivered by IFI.

The formal approach to EDM Training is complimented with on-site training. Regular site visits with consutants and

OPW’s Environment Section provide further guidance and advice to operational staff. Auditing of operational

staff on the implementation of the Environmental Drainage Maintenance Guidance Notes (Ten Steps to

Environmentally Friendly Maintenance) is also carried out by both IFI and OPW’s Environment Section.

In addition, other environmental training takes place as deemed beneficial, e.g. in 2008, the majority of the

technical and operational staff were trained in Otter Awareness. This course, provided by the Department of

Zoology, Trinity College Dublin, included presentations on Otter ecology, and on-site identification of Otter signs

and suitable habitat.

More recently, an environmental training course was designed and provided by JBA to all OPW staff in 2017

and 2018. It was given in three different stages. Management staff were given a more detailed 2-day course

in Environmental and Ecological training. Ground staff were given 1.5 days of training in the environment and

ecology. Modules were designed to assist staff in understanding the relevant legislation, recognising ecologically

sensitive habitats and species, invasive non-native species identification and general environmental and

ecological training relevant to their work. This included a half day practical session where ecologists

demonstrated the identification of the elements taught in the classroom, in the field. Training in the completion of

an Environmental Risk Assessment and Bridge Inspections from an ecological perspective, was designed and

provided by JBA Consulting to OPW Foremen and selected engineering staff in 2018. Training with regard to

the new OPW procedures, Environment Guidance: Drainage Maintenance and Construction was delivered in

house by OPW Environment Section in June 2019. All relevant staff were trained in how to use the new Guidance

and workshops on how to use Environmental Data EP6 proved useful.

2.2.11 Environmental Audits

A portion of operational crews are audited annually by the OPW Environment Section and OPW’s Environmental

Consultants for the implementation of the Environmental Drainage Maintenance Guidance Notes (Ten Steps to

Environmentally Friendly Maintenance) and the OPW’s Environmental Guidance and EPs. Auditing is carried out

separately by both OPW Environment Section and OPW Environmental Consultants on a rotational basis to

ensure all operational crews are audited at least once every three years. All audit results are forwarded to the

relevant Engineer for that Scheme within two working weeks. In the event of an audit showing elements of

unreasonable non-compliance with procedures, the relevant Engineer will be notified within one working day.

Audit results are also forwarded to OPW Systems Manager for inclusion in monthly regional benchmarking

reports.



2.2.12 Environmental Guidance: Drainage Maintenance and Construction and Environmental

Procedures (Eps)

The OPW’s Environmental Guidance: Drainage Maintenance and Construction, Management Procedures set out

how regional management staff manage a range of environmental aspects, including programming of works to

accommodate certain environmental windows or restrictions on timing of works, and recording of data. A total

of 33 No. Environmental Procedures (EPs) are applied to the works. These EPs set out actions designed to

eliminate, or substantially reduce likely impacts to identified species and their associated habitats. Environmental

Procedures are broken down into the following:

Section 1A Drainage Maintenance Planning Procedures (EP1- 5)

Section 1B, Drainage Maintenance Implementation Procedures (EP6 – 13), including procures for the 10 Steps to

Environmentally Friendly Maintenance, River Enhancement and Tree and Vegetation Management.

Section 2 Construction Procedures (EP14 – 17), including Construction and Environmental Management, Ecological

friendly culverts ad water pollution management);

Section 3 Invasive Species Procedures EP18 A – D) including Procedures for general and high-level biosecurity

and treatments;

Section 4 Animal and Plant Procedures (EP19-28)

▪ EP19 Salmonid

▪ EP20 Otter

▪ EP21 Lamprey

▪ EP22 Crayfish

▪ P 23 Badger

▪ EP24 Bank Nesting Birds

▪ EP25 Birds

▪ EP26 Bats

▪ EP27 Rare Plants

▪ EP28 Fresh Water Pearl Mussel

Section 5 Habitat Procedures EP30 – 33):

▪ EP30 Alluvial (Wet Woodland)

▪ EP31 Wetland

▪ EP32 Mudflat

▪ EP33 Floating River Vegetation Habitat.

All Environmental Procedures are available in the OPW’s “Environmental Guidance Drainage Maintenance &

Construction” (OPW. 2019).

This document can also be downloaded from https://www.opw.ie/en/media/environmental-guidance-

drainage-maintenance-and-construction-2019.pdf.

2.3 The Corrib Arterial Drainage Scheme

The Corrib Arterial Drainage Scheme is located in County Galway. It includes 1687.6km of watercourse and

8.2km of embankment. The Corrib catchment has a total benefiting area of 34,520ha. This large scheme is sub-

divided into three separate areas; the Corrib Clare, Corrib Headford and Corrib Mask.

http://www.opw.ie/en/media/OPW%20Environmental%20Management%20Protocols%20%26%20SOPs%20April%202011.pdf



Figure 2-3: Map of the Corrib Scheme as identified in the AA Screening Report (2014)

The construction of the scheme, started in 1954 in the Corrib Clare area and was completed in 1986 in the Corrib

Mask area under the 1945 Arterial Drainage Act. Maintenance has been ongoing since completion of the scheme.

2.4 Drainage Maintenance Works Proposed for the Corrib Arterial Drainage Scheme

Within the Corrib Arterial Drainage Scheme the exact location and type of required maintenance activity varies

over time. The screening assessment (JBA Consulting, 2014a) was conducted on the assumption that all channels

and embankments will be maintained during a 5-year naintenance cycle. However, this Appropriate Assessment

is based on more detailed information provided on the timing, frequency and nature of maintenance operations

to be conducted on each channel and embankment. During the period 2020 to 2024 a range of maintenance

activities are proposed for the watercourses in the Corrib Arterial Drainage Scheme, including:

▪ A - Silt and vegetation management

▪ B - Aquatic vegetation cutting

▪ C - Bank protection

▪ D - Bush cutting/Branch trimming

▪ E - Tree Cutting

▪ F- Other

It is currently not known where structural maintenance operations, or embankment maintenance activities as

detailed in Table 2.1 and 2.2, are proposed, and therefore it will be assumed that potentially these activities

could occur on all embankments and structures within the scheme area during the period 2020-2024.

The spreadsheet in Appendix A provides full details of the drainage maintenance activities proposed for the

Corrib Arterial Drainage Scheme for the period 2020 to 2024. It should be noted that:

▪ CH4 Sect. 1 is a duplication of channel C14 on the Corrib Clare Scheme



▪ C3/35/8 Sect.1 and C3/35/8 Sect. 2 on the Corrib Clare Scheme have been deleted as

duplication data

▪ C3/47 Sect.1 on the Corrib Clare Scheme has been deleted as duplication data

▪ C3/51 Sect.1 on the Corrib Clare Scheme has been deleted as duplication data

▪ No maintenance is scheduled in the period 2020-2024 on the following channels:

Table 2-3 Channels excluded from drainage maintenance

Scheme Section Channel Referance

Corrib Headford ED1/1



Corrib Clare C3/18/1/2



Corrib Clare F190

Corrib Clare F495

Corrib Mask CM10

Corrib Mask CM10/1

Corrib Mask CM10/2

Corrib Mask CM10/3

Corrib Mask CM10/4

Corrib Mask CM5/10/2

Corrib Mask CM5/10/5

Corrib Mask CM8/4

Corrib Mask CM8/1/1

Corrib Mask CM8/1/1/1

Corrib Mask CM8/1/2

Corrib Mask CM8/1/2/1

Corrib Mask CM9/6

Corrib Mask F278(A)

Corrib Mask F445

Corrib Mask SM100/2

Corrib Mask SM100/3

Corrib Mask SM88/1

Corrib Mask SM89/2

Corrib Mask SM89/2/1

Corrib Mask SM89/2/2

Corrib Mask SM90/1

▪ Channel C7 has been subsumed into CH1 section

▪ Channel F.363 has been subsumed into C3 Sect. 26

▪ Channel F.508 has been subsumed into C3/35/12 Sect. 1 and 2

▪ Channel F.765 has been subsumed into C3 Sect. 45

▪ Channel F.772 has been subsumed into &.772/2



▪ Channel F.797 has been subsumed into SG18/5

▪ F837 on the Corrib Clare Scheme has been deleted as duplicate data

▪ Channel CM4/18 Proposed was never completed as part of the scheme.

▪ Channel SM111/1 has been deleted.



3 Screening Assessment Results

3.1 Introduction

An Appropriate Assessment screening assessment, addressing Stage 1 of the process, has already been

completed for Corrib Arterial Drainage Scheme (JBA Consulting, 2014a). This identified that likely significant

effects on European Sites may occur as a result of the proposed maintenance activities and therefore a Stage 2

Appropriate Assessment is necessary.

The Stage 1 Screening Assessment was conducted in line with guidance produced for the OPW (Ryan Hanley,

2014a, b and c). This methodology is based on source > pathway > receptor chain principles and involves

assessing likely significant effects on European sites within the zone of influence of the proposed drainage

maintenance in relation to three pathways:

1. Surface water

2. Land & air

3. Groundwater

The screening assessment involved assessing the impacts of drainage maintenance operations within the arterial

drainage scheme, and its zone of influence, in relation to each of the three pathways individually. Conclusions

were then drawn to identify which channels and embankments within a scheme could impact upon European sites.

3.1.1 Surface Water Pathways

As a result of the screening assessment (JBA Consulting, 2014a) maintenance activities on those watercourses and

embankments shown in Figure 3-1 to Figure 3-4 were identified as potentially resulting in significant adverse

impacts on European sites via surface water pathways. Specifically, the European sites that may be adversely

impacted upon are:






















Figure 3-1: Channels and embankments with potential impacts via surface water pathways - North West Corrib as

identified in the AA Screening Report (2014)

Figure 3-2: Channels and embankments with potential impacts via surface water pathways - North East Corrib as




Figure 3-3: Channels and embankments with potential impacts via surface water pathways - South West Corrib as


Figure 3-4: Channels and embankments with potential impacts via surface water pathways - South East Corrib as




3.1.2 Land & Air Pathways



impacts on European sites via land and air water pathways. Specifically, the European sites that may be

adversely impacted upon are:






















Figure 3-5: Channels and embankments with potential impacts via land and air pathways - North West Corrib as


Figure 3-6: Channels and embankments with potential impacts via land and air pathways - North East Corrib as




Figure 3-7: Channels and embankments with potential impacts via land and air pathways - South West Corrib as


Figure 3-8: Channels and embankments with potential impacts via land and air pathways - South East Corrib as




3.1.3 Groundwater Pathways



impacts on European sites via groundwater pathways. Specifically, the European sites that may be adversely

impacted upon are:



























Figure 3-9: Channels and embankments with potential impacts via groundwater pathways - North West Corrib as


Figure 3-10: Channels and embankments with potential impacts via groundwater pathways - North East Corrib as




Figure 3-11: Channels and embankments with potential impacts via groundwater pathways - South West Corrib as


Figure 3-12: Channels and embankments with potential impacts via groundwater pathways - South East Corrib as




3.2 Screening Assessment Conclusions

The Screening Assessment (JBA Consulting, 2014a) identified that the sites detailed in Table 3-1 were likely to

be significantly affected by drainage maintenance operations undertaken within the Corrib Arterial Drainage

Scheme. These conclusions are based on the assumption that all drainage maintenance activities are to be

undertaken on all watercourses, embankments and structures during the life of the plan (2020-2024).

Table 3-1Screening Assessment Conclusions

Site

Pathway of Impact Comment

Surface

Water

Land and

Air

Ground

water

Ardkill Turlough SAC

(000461)

The turlough habitats within this SAC could be adversely

impacted upon by drainage maintenance operations

within the same groundwater body that this site is situated

in. Impacts from surface water and land and air pathways

will not arise.

Balla Turlough SAC

(000463)

No adverse impacts via any of the three pathways were

identified in relation to these sites

Ballinafad SAC (002081)

Ballymaglancy Cave,

Cong SAC (000474)

The cave habitats supporting the Lesser Horseshoe Bat

population within this site could be adversely impacted

upon by drainage maintenance operations via

groundwater pathways only.

Carrowkeel Turlough SAC

(000475)

The turlough habitats within this site may be adversely

impacted upon by drainage maintenance operations via

all three pathways as scheme watercourses pass through

the SAC boundaries.

Cloughmoyne SAC

(000479)

The limestone pavements within this site are not surface or

groundwater dependent and can consequently be only

adversely impacted upon by land and air pathways only.

Clyard Kettle-Holes SAC

(000480)

The turlough, fen and woodland habitats within this site

may be adversely impacted upon by drainage

maintenance operations via all three pathways as scheme

watercourses pass through the SAC boundaries.

Connemara Bog Complex

SAC (002034)

This site is designated for a large number of qualifying

interests. Different pathways of impact will affect different

qualifying interests depending on their location and

nature. However, the coastal lagoon, reef and old sessile

oak woodland habitats will not be affected via any

pathway.

Galway Bay Complex

SAC (000268)

This site is designated for a wide range of habitat types

and some species, however, given their location within this

large site only some qualifying interests (i.e. mudflat and

sandflats, coastal lagoons, large shallow inlets and bays

and otter) are vulnerable to drainage maintenance

activities.

Gortnandarragh

Limestone Pavement SAC

(001271)


identified in relation to this site.



Site


Surface

Water

Land and

Air

Ground

water

Greaghans Turlough SAC

(000503)

The turlough habitats within this SAC could be adversely

impacted upon by drainage maintenance operations

within the same groundwater body that this site is situated

in. Impacts from surface water and land and air pathways

will not arise.

Kildun Souterrainn SAC

(002320)



Kilglassan/Caheravoostia

Turlough Complex SAC

(000504)

The turlough habitats within these sites may be adversely


all three pathways as scheme watercourses pass throught

the SAC boundaries. Levally Lough SAC

(000295)

Lisnageeragh Bog and

Ballinastack Turlough

SAC (000296)

The turlough and raised bog habitats within this site may

be adversely impacted upon by drainage maintenance

operations via all three pathways as scheme watercourses

pass throught the SAC boundaries. The bog pool habitats

will not be adversely affected by drainage maintenance

operations.

Lough Carra/Mask

Complex SAC (001774)


interests. Different pathways of impact will affect

different qualifying interests depending on their location

and nature. Only the Lesser Horseshoe Bat populations

within the site will be unaffected by drainage

maintenance operations.

Lough Corrib SAC

(000297)




and nature. Only the old oak woodland habitats isolated

on the Hill of Doon will be unaffected by drainage


Lough Lurgeen Bog/

Glenamaddy Turlough

SAC (000301)

The turlough, raised bog and bog pool habitats within this

site may be adversely impacted upon by drainage

maintenance operations via all three pathways as scheme

watercourses pass throught the SAC boundaries.

Maumturk Mountains SAC

(002008)

This site is designated for a number of qualifying interests.

Of these only Atlantic Salmon populations may be

adversely impacted upon by drainage maintenance

operations via surface water and land and air pathways.

The blanket bog and the bog pool habitats they support

could also be impacted upon via groundwater pathways.

All other qualifying interests will remain unaffected.

Mocorha Lough SAC

(001536)

The calcareous fen habitats for which this site is

designated could be impacted upon by drainage

maintenance operations via surface and groundwater

pathways as this habitat type is surface water and

groundwater dependent. No impacts via land and air



Site


Surface

Water

Land and

Air

Ground

water

pathways will arise as no works within the site boundaries

will take place.

Monivea Bog SAC

(002352)

The raised bog and bog pool habitats within this site may

be adversely impacted upon by drainage maintenance

operations via land and air and groundwater pathways.

The habitat types for which the site is designated are not

surface water dependent and so cannot be impacted

upon via that pathway.

Moore Hall (Lough

Carra) SAC (000527)


identified in relation to these sites

Mweelrea/Sheeffry/Erriff

Complex SAC (001932)

River Moy SAC (002298)

Ross Lake and Woods

SAC (001312)




and nature. Only the Lesser Horseshoe Bat populations

within the site will be unaffected by drainage


Shrule Turlough SAC

(000525)



all three pathways as scheme watercourses pass through

the SAC boundaries.

Skealoghan Turlough SAC

(000541)



Towerhill House SAC

(002179)

The Lesser Horseshoe Bat population for which this site is

designated roosts in an area with several wetland habitat

types which provide foraging habitat and could be

adversely affected by drainage maintenance activities

via groundwater pathways.

Williamstown Turloughs

SAC (002296)



surface water pathways only.

Inner Galway Bay SPA

(004031)

This site is designated for a large number of bird species

which can be impacted upon by drainage maintenance

activities via one or more pathways of impact. The

exception to this are the populations of Sandwich and

Common Tern which will be unaffected by drainage


Lough Carra SPA

(004051)

The Common Gull populations for which this site is

designated may be adversely impacted upon via land

and air and surface water pathways.



Site


Surface

Water

Land and

Air

Ground

water

Lough Corrib SPA

(004042)



activities via one or more pathways of impact.

Lough Mask SPA

(004062)



activities via one or more pathways of impact.

Note:

Red = likely significant effect Green = no likely significant effect

Figure 3-13: Map of all channels, embankments and structures where significant likely effects may arise - Corrib NW

as identified in the AA Screening Report (2014)



Figure 3-14: Map of all channels, embankments and structures where significant likely effects may arise - Corrib NE


Figure 3-15: Map of all channels, embankments and structures where significant likely effects may arise - Corrib SW




Figure 3-16: Map of all channels, embankments and structures where significant likely effects may arise - Corrib SE


4 European Sites within the Zone of Influence of Drainage Maintenance Activities

4.1 Introduction

This chapter provides baseline information on the European sites within the Zone of Influence of the drainage

maintenance activities (i.e. those screened into the assessment as detailed in Table 3-1). A short description for

each site is provided, along with details of the qualifying interest/special conservation interests, conservation

objectives, the attributes used to define favourable conservation status and site vulnerabilities. However, for

many sites, site specific conservation objectives have not yet been developed for the qualifying interest/special

conservation interest present. In these instances, attributes have been taken from similar or nearby sites where

the same qualifying interest/special conservation interests, or from similar habitats/species, and these are

assumed to be appropriate for the sites detailed.

4.2 Ardkill Turlough SAC (000461)

Ardkill Turlough is one of a group of five turloughs situated within a basin. At Ardkill Turlough, there is no above-

ground inflow into the basin, consequently peat has formed in the lower-lying parts of the site. The turlough also

contains two ponds; a deEPand a shallow one. The basin floods regularly and the lack of drainage across the

site is apparent. The site is unusual, due to the large fluctuations in water level and exposed areas of limestone

(NPWS, 2013c).

The vegetation structure across the site is highly diverse due to the fluctuating water level across the area and

occurrence of bare rock. Species recorded at Ardkill include Common Meadow-rue Thalictrum flavum, which is

only known at this site in County Mayo. Both water bodies support a diverse community of aquatic plants including



Amphibious Bistort Polygonum amphibium, Great Yellow-cress Rorippa amphibia, Spiked Water-milfoil

Myriophyllum spicatum and Unbranched Bur-reed Sparganium emersum (NPWS, 2013c).

The site also supports breeding Lapwing, Snipe and Common sandpiper (NPWS, 2013c).

4.2.1 Qualifying Interests

Table 4-1 Qualifying Interests of Ardkill Turlough SAC (000461)

Code Qualifying Interests Attributes

3180 Turloughs - Habitat area

- Habitat distribution

- Hydrological regime: flood duration, frequency area, depth, permanently flooded

area

- Soil type: area

- Soil nutrient status: nitrogen and phosphorous

- Physical structure: bare ground

- Chemical processes: calcium carbonate deposition and concentration

- Water quality: nutrients, colour, phytoplankton, epiphyton

- Active peat formation

- Vegetation composition: area of vegetation communities, vegetation zonation

- Vegetation structure: sward height, turlough woodland

- Typical species: terrestrial, wetland and aquatic plants, invertebrates and birds

- Fringing habitats: area

From: Galway Bay Complex SAC Conservation Objectives (NPWS, 2013o)

4.2.2 Conservation Objective

The Conservation Objective for Ardkill Turlough SAC is to or restore the favourable conservation condition of the

Annex I habitat for which the SAC has been selected (see Table 4-1) (NPWS, 2018h).

Favourable conservation status of a habitat is achieved when:

▪ its natural range, and area it covers within that range, are stable or increasing, and

▪ the specific structure and functions which are necessary for its long term maintenance exist and are

likely to continue to exist for the foreseeable future, and

▪ the conservation status of its typical species is favourable.

▪ population dynamics data on the species concerned indicate that it is maintaining itself on a long

term basis as a viable component of its natural habitats, and

▪ the natural range of the species is neither being reduced nor is likely to be reduced for the

foreseeable future, and

▪ there is, and will probably continue to be, a sufficiently large habitat to maintain its populations

on a long term basis.

4.2.3 Site Vulnerabilities

NPWS (2017a) identify that Ardkill Turlough SAC is vulnerable to:

▪ Changes in groundwater conditions due to intensive farming in vicinity.



4.3 Ballymaglancy Cave, Cong SAC (000474)

Ballymaglancy Cave is a linear stream cave which is of international significance as it supports a population of

Lesser Horseshoe Bat. The cave entrance is approximately 2m high and 3m wide. There are examples of

Carboniferous colonial coral in the floor of the cave, and it is an excellent example of a natural limestone cave

with rock formations (NPWS, 2013d).

Lesser Horseshoe Bat have been known to use the cave for many years, with survey data suggesting that up to

50 hibernating bats are present. The numbers vary with temperature and most bats can be found hibernating

within 20m of the cave entrance. The cave is ideal habitat for this species as it offers a number of low, dry

passageways (NPWS, 2013d).


Table 4-2 Qualifying Interests of Ballymaglancy Cave, Cong SAC (000474)


8310 Caves not open to

the public

There are no Site-Specific Conservation Objectives for this habitat available which could

have been used in this assessment. As a result, the following attributes have been

proposed based on professional judgement;

- Habitat area


- Hydrological regime

1303 Lesser Horseshoe Bat

Rhinolophus

hipposideros

- Population per roost

- Winter roosts

- Number of auxiliary roosts

- Extent of potential foraging habitat

- Linear features: length

- Light pollution


The Conservation Objective for Ballymaglancy Cave, Cong SAC is to restore the favourable conservation

condition of the Annex I habitat(s) and the Annex II species for which the SAC has been selected (see Table 4-2)

(NPWS, 2018i).

Section 4.2.2 above details the criteria used to assess favourable condition.


Natura 2000 Data Form (2017b) identifies that Ballymaglancy Cave, Cong SAC is vulnerable to:

▪ Damage/degradation of cave structures from visitors during the winter months.

▪ Disturbance to hibernating bats from visitors.

4.4 Carrowkeel Turlough SAC (000475)

Carrowkeel Turlough is contained within a linear basin, with no signs of external drainage apparent, and

consequently it is oligotrophic in character. The Carrowkeel Turlough has a high diversity of vegetation types

which are associated with the water quality and depth across the site. Vegetation within the lake itself consists

of Fine-leaved Water-dropwort Oenanthe aquatica, Amphibious Bistort Polygonum amphibium, Water Horsetail

Equisetum fluviatile and the mosses Drepanocladus revolvens and Calliergon giganteum. Thread-leaved Water-

crowfoot Ranunculus trichophyllus, Lesser Marshwort Apium inundatum and Broad-leaved Pondweed

Potamogeton natans are also present (NPWS, 2013e).



The north-eastern end of the site contains Bladder-sedge Carex vesicaria, Bogbean Menyanthes trifoliata,

Water-plantain Alisma plantago-aquatica and Narrow-leaved Water-plantain A. lanceolatum, which is a rare

combination of vegetation within a turlough (NPWS, 2013e).


Table 4-3 Qualifying Interests of Carrowkeel Turlough SAC (000475)





area

- Soil type: area












The Conservation Objective for Carrowkeel Turlough SAC is to maintain or restore the favourable conservation

condition of the Annex I habitat(s) and/or the Annex II species for which the SAC has been selected (see Table

4-3) (NPWS, 2018j).



Background data from the Natura 2000 Data Form for Carrowkeel Turlough SAC (2018b) identifies that the site

is vulnerable to:

▪ Diffuse pollution to surface waters due to agricultural and forestry activities.

▪ Infilling of ditches, dykes, ponds, pools, marshes or pits

▪ Grazing pressures.

4.5 Cloughmoyne SAC (000479)

Cloughmoyne SAC is located on a low limestone ridge which spreads out southwards and comprises of lake and

fen habitat. The dominant habitat present at the SAC is the presence of 40ha of limestone pavement in a

'shattered form' which supports calcareous grassland and heath species. Of particular note is the presence of the

rare Limestone Fern Gymnocarpium robertianum, which is legally protected (Flora (Protection) Order, 1999)

(NPWS, 2013f).

The site also includes areas of species-rich grasslands where Blue Moor-grass Sesleria albicans, Sweet Vernal-

grass Anthoxanthum odoratum, Red Fescue Festuca rubra, Common Bird's-foottrefoil Lotus corniculatus, Juniper

Juniperus communis, and Madder Rubia peregrina grow. Denseflowered Orchid Neotinea maculata has also



been recorded on the site and is designated as rare, and is consequently legally protected (Flora (Protection)

Order, 1999). The site also contains species-poor fen habitat which is dominated by Black Bog-rush Schoenus

nigricans (NPWS, 2013f).


Table 4-4 Qualifying Interests of Cloughmoyne SAC (000479)


8240 Limestone Pavement - Habitat area


- Vegetation composition: positive indicator species

- Vegetation composition: bryophyte layer

- Vegetation composition: negative indicator species

- Vegetation composition: non-native species

- Vegitation composition: scrub

- Vegetation composition: bracken cover

- Vegitation structure: woodland canopy

- Vegitation structure: dead wood

- Physical structure: disturbance

- Indicators of local distinctiveness


The Conservation Objective for Cloughmoyne SAC is to restore the favourable conservation condition of Limestone

pavements* in Cloughmoyne SAC (see Table 4-4) (NPWS, 2019a).



Background data from the Natura 2000 Data Form for Cloughmoyne SAC (2017c) identifies that the site is

vulnerable to:

▪ Disposal of household/recreational facility waste

▪ Sand and gravel extraction

▪ Agricultural activities from both within, and adjacent to the site which threaten rare species

associated with the area.

▪ Overuse and application of fertiliser to site.

4.6 Clyard Kettle-Holes SAC (000480)

The site comprises of a series of small lakes and turloughs which are located between stony hillocks. Some lakes

are connected, but others appear to fill and empty via subterranean means, consequently, diverse vegetation

communities can be found across the site (NPWS, 2013e).

The most dominant plant community within this SAC is Cladium Fen, which is characterised by the presence of

species such as Great Fen-sedge Cladium mariscus, with Black Bog-rush Schoenus nigricans and Slender Sedge

Carex lasiocarpa. Reedbeds are also present. Within areas of quaking marsh, Tubular Water-dropwort

Oenanthe fistulosa and Bogbean Menyanthes trifoliata are present (NPWS, 2013g).

Each turlough has its own characteristics; for example, to the north of the site an area of 12ha floods in the

winter. The inundated vegetation is coated in calcium carbonate as a result of the rising water level. This turlough

drains to a swallow hole in the north-west corner, with summer pools supporting stands of Great Fen-sedge. Two



further turlough areas occur to the west, at Cahernagry East, which floods to an area of 12 ha, and at

Caherhemush – Ballywalter, which floods to over 25 ha (NPWS, 2013g).


Table 4-5 Qualifying Interests of Clyard Kettle-Holes SAC (000480)





area

- Soil type: area











7210 Calcareous fens

with Cladium

mariscus and

species of the

Caricion davallianae

- Habitat area



- Peat formation

- Water quality: nutrients

- Vegetation composition: typical species, trees and shrubs

- Physical structure: disturbed bare ground, drainage

From: Galway Bay Complex SAC Conservation Objective (NPWS, 2013o)


The Conservation Objective for Clyard Kettle-Holes SAC is to maintain or restore the favourable conservation


4-5) (NPWS, 2018e).



Background data from the Natura 2000 Data Form for Clyard Kettle Holes SAC (2014d) identifies that the site

is vulnerable to:

▪ Agricultural practices including increased grazing pressure and fertiliser application.

▪ Increased scrub removal.

▪ Intensification of agriculture within and around the site.

▪ Introduction of external drainage.

▪ Implications of flood relief schemes, particularly at Thomastown Turlough.



4.7 Connemara Bog Complex SAC (002034)

The Connemara Bog complex SAC is large site which supports a range of habitats, including blanket bog (as a

core interest), heath, fen, woodlands, lakes, rivers and coastal habitats. The bog is characterised by areas of

deeper peat with rocky granite outcrops. The main habitat is Atlantic blanket bog, and most of the area is

covered by peat greater than 1m in depth. This blanket bog habitat is associated with hummock/hollow systems,

inter-connecting bog pools, flushes, transition and quaking mires, freshwater marshes, lakeshore, lake and river

systems (NPWS, 2015a).

The dominant species present on the blank bog include Black Bog-rush Schoenus nigricans, Purple Moor-grass

Molinia caerulea, Cross-leaved Heath Erica tetralix, Common Cotton-grass Eriophorum angustifolium, Bog

Asphodel Narthecium ossifragum, White Beak-sedge Rhynchospora alba and bog moss species Sphagnum spp.

Rhynchosporion vegetation is found on the blanket bog by lake and pool margins, in wet hollows and in quaking

areas. Wet heath is widespread (NPWS, 2015a).

Other habitats present within the SAC are lakes, both oligotrophic and dystrophic. Dystrophic lakes are

concentrated in the west of the site and are smaller than their oligotrophic counterparts, which are instead

shallower (along their margins) and contain less peat substrate. Both types of lakes contain aquatic vegetation

along their edges. The rare species Slender Naiad Najas flexilis and Pillwort Pilularia globulifera have both

been recorded from oligotrophic lakes at this site. Transition mire is present along lake margins and bog streams.

The rare and legally protected species Slender Cotton-grass Eriophorum gracile occurs in this habitat (NPWS,

2015a).

The SAC contains the main river systems of the Owenmore River, the Glashanasmearany and Derrygauna Rivers,

the Cashla River, the Glengawbeg River and the Owenboliska River and its tributaries (NPWS, 2015a).

Grassland habitats across the site contain Molinia meadow which contain Purple Moor-grass, Meadow Thistle

Cirsium dissectum, Sharp-flowered Rush Juncus acutiflorus and Tormentil Potentilla erecta. There are also small

areas oak woodland, and well-developed alkaline fen. Four large lagoons occur within this site: Lough Ahalia,

Doire Bhanbh, Lough Aconeera and Salt Lake. All four are regarded as saline lake lagoons and they range in

size from 1 - 90 ha. The lagoons vary in their salinity, vegetation communities and associated fauna and all

support a number of lagoonal specialists (NPWS, 2015a).

Nine species protected under the Flora (Protection) Order, 1999, occur within this site: Forked

Spleenwort Asplenium septentrionale, Parsley Fern Cryptogramma crispa, Bog Hair-grass Deschampsia setacea,

Slender Cotton-grass, Bog Orchid Hammarbya paludosa, Slender Naiad, Heath Cudweed Omalotheca sylvatica,

Pillwort and Pale Dog-violet Viola lactea (NPWS, 2015a).

Fauna recorded at the Connemara Bog complex includes Atlantic Salmon, Otter, and Irish Hare. The site is of

nation importance for bird species throughout the year and Greenland White-fronted Goose are found on the

Bog. The site is of breeding significance for Cormorants, Golden Plover, Merlin, Choughs and Common Terns

(NPWS, 2015a).


Table 4-6 Qualifying Interests of Connemara Bog Complex SAC (002034)


1150 Coastal Lagoons - Habitat area


- Salinity regime


- Barrier connectivity: between lagoon and sea




- Water quality: Chlorophyll a, Molybdate Reactive Phosphorous (MRP), Dissolved

Inorganic Nitrogen (DIN)

- Depth of macrophyte colonisation

- Typical plant species

- Typical animal species

- Negative indicator species

1170 Reefs - Distribution

- Habitat area

- Community extent

- Community structure: Biological composition

3110 Oligotrophic waters

containing very few

minerals of sandy

plains (Littorelletalia

uniflorae)

- Habitat area


- Typical species

- Vegetation composition: characteristic zonation

- Vegetation distribution: maximum depth

- Hydrological regime: water level fluctioations

- Lake substratum quality

- Water quality: transparency, nutrients, phytoplankton biomass, phytoplankton

composition, attached algal biomass, macrophyte status

- Acidification status

- Water colour

- Dissolved organic carbon

- Turbidity

- Fringing habitat

3130 Oligotrophic to

mesotrophic standing

waters with vegetation

of the Littorelletea

uniflorae and/or

Isoeto-Nanojuncetea

3160 Natural dystrophic

lakes and ponds

3260 Water courses of

plain to montane

levels with the

Ranunculion fluitantis

and Callitricho-

Batrachion vegetation

- Habitat area


- Hydrological regime: river flow, groundwater discharge

- Substratum composition: particle size range


- Vegetation composition: typical species

- Floodplain connectivity

- Riparian habitat

4010 Northern Atlantic wet

heaths with Erica

tetralix

- Habitat area


- Ecosystem function: soil nutrients

- Community diversity

- Vegetation composititon: cross-leaved heath, positive indicator species, lichens and

bryophytes, ericoid species and crowberry, dwarf shrub species, negative indicator

species, non-native species, native tree and shrubs, bracken, soft rush

- Vegetation structure: Sphagnum condition, signs of browsing, burning



4030 European dry heaths - Habitat area







- Vegetation composititon: number of positive indicator species, lichens and bryophytes,

cover of positive indicator species, negative indicator species, non-native species,

native tree and shrubs, bracken, soft rush

- Vegetation structure: ling, signs of browsing, burning, dwarf shrub composition, growth

phase of ling, disturbed bare ground


6410 Molinia meadows on

calcareous, peaty or

clavey-silt-laden soils

(Molinion caeruleae)

- Habitat area


- Vegetation composititon: typical species, negative indicator species, non-native

species, moss species

- Vegetation structure: woody species and bracken, broadleaf herb: grass ratio, sward

height, litter

- Physical structure: bare ground, bare soil, disturbance

7130 Blanket Bogs (Active) - Habitat area


- Ecosystem function: peat formation, hydrology


- Vegetation composition: positive indicator species, lichens and bryophytes, potential

dominant species, negative indicator species, non0native species, native tree and

scrub


- Physical structure: disturbed bare ground, drainage, erosion


7140 Transition mires and

quaking bogs

- Habitat area




- Vegetation composition: number of positive indicator species, number of core positive

indicator species, cover of positive indicator species, negative indicator species, non-

native species

- Vegetation structure: height



7150 Depressions on peat

substrates of the

Rhynchosporion

- Habitat area



- Vegetation composition: positive indicator species, Rhynchospora spp., potential

dominant species, negative indicator species, non-native species, native tree and scrub


- Physical structure: disturbed bare ground, drainage, erosion


7230 Alkaline Fens - Habitat area







- Vegetation composition: number of positive indicator species, cover of positive

indicator species, negative indicator species, non-native species, native tree and scrub,

soft rush and common reed


- Physical structure: disturbed bare ground, drainage, tufa formation


91A0 Old sessile oak woods

with Ilex and Blechnum

in British

Isles

- Habitat area


- Woodland size

- Woodland structure: cover and height, community diversity and extent, natural

regeneration, dead wood, veteran trees, indicators of local distinctiveness,

- Vegitation composition: native tree cover, typical species, negative indicator species

1065 Marsh Fritillary

Euphydryas aurinia

- Distribution

- Proof of breeding

- Potential habitat

1106 Atlantic Salmon

Salmo salar

- Distribution: extent of anadromy

- Adult spawning fish

- Salmon fry abundance

- Out-migrating smolt abundance

- Number and distribution of redds

- Water quality

1355 Otter Lutra - Distribution

- Extent of terrestrial habitat

- Extent of marine habitat

- Extent of freshwater (river) habitat

- Extent of freshwater (lake/lagoon) habitat

- Couching sites and holts

- Fish biomass available

- Barriers to connectivity

1833 Slender Naiad Najas

flexilis

- Population extent

- Population depth

- Population viability

- Population abundance

- Species distribution

- Habitat extent

- Hydrological regime: water level fluctuations


- Water quality


- Water colour

- Accociated species

- Fringe habitat


The Conservation Objective for Connemara Bog Complex SAC are as follows (NPWS, 2015g);

▪ To maintain the favourable conservation conditions of Coastal lagoons,



▪ To maintain the favourable conservation condition of Reefs,

▪ To maintain the favourable conservation conditions of Oligotrophic waters containing very

few minerals of sandy plains

▪ To maintain the favourable conservation condition of Oligotrophic to mesotrophic standing

waters with vegetation of the Littorelletea uniflorae and/or Isoeto-Nanojuncetea

▪ To maintain the favourable conservation condition of Natural dystrophic lakes and ponds

▪ To maintain the favourable conservation condition of Water courses of plain to montane

levels with Ranunculion fluitantis and Callitricho-Batrachion vegetation

▪ To restore the favourable conservation conditions of Northern Atlantic wet heaths with

Erica tetralix

▪ To restore the favourable conservation condition of European dry heaths

▪ To maintain the favourable conservation condition of Molinia meadows on calcareous,

peaty or clayey-silt-laden soils (Molinion caeruleae)

▪ To restore the favourable conservation condition of Blanket bogs

▪ To restore the favourable conservation conditions of Transition mres and quaking bogs

▪ To restore the favourable conservation condition of Depressions on peat substrates of the

Rhynchosporion

▪ To restore the favourable conservation condition of Alkaline fens

▪ To maintain the favourable conservation condition of Old sessile oak woods with Ilex and

Blechnum in the British Isles

▪ To maintain the favourable conservation condition of Marsh Fritillary

▪ To restore the favourable conservation condition of Atlantic Salmon

▪ To maintain the favourable conservation condition of Otter

▪ To maintain the favourable conservation condition of Slender Naiad



Background data from the Natura 2000 Data Form for Connemara Bog SAC (2017e) identifies that the site is

vulnerable to:

▪ Grazing pressure from sheep.

▪ Peat cutting, both by hand and machinery including using 'Difco' and excavator machines.

▪ Deliberate burning of bog and heath.

4.8 Galway Bay Complex SAC (000268)

Galway Bay SAC is located on the west coast of Ireland and site comprises the inner, shallow part of a large

bay which is partially sheltered by the Aran Islands. The Burren karstic limestone fringes the southern sides and

extends into the sub-littoral environment. West of Galway city the bedrock geology is granite. There are

numerous shallow and intertidal inlets on the eastern and southern sides, notably Muckinish, Aughinish and

Kinvarra Bays. A number of small islands composed of glacial deposits are located along the eastern side,

including Eddy Island, Deer Island and Tawin Island. The site contains a diverse range of habitats including marine,

coastal and terrestrial habitats (NPWS, 2015b).

The littoral communities present in Galway Bay South range from rocky terraces, sand dunes and beaches. The

intertidal sediments of Galway Bay support specialist communities and the country's only recorded example of



a community characterised by Fucus serratus with sponges, ascidians and red seaweeds on tide-swept lower

eulittoral mixed substrata (NPWS, 2015b).

Saltmarshes are frequent within the SAC and contain species such as Thrift Armeria maritima, Red Fescue Festuca

rubra, Common Scurvy-grass Cochlearia officinalis, Lax-flowered Sealavender Limonium humile, Common

Saltmarsh-grass Puccinellia maritima, Saltmarsh Rush Juncus gerardi and Sea Rush Juncus maritimus. A number of

locally rare vascular plant species also grow in saltmarsh areas within the site, including Reflexed Saltmarsh-

grass Puccinellia distans and Sea-purslane Halimione portulacoides, which are both relatively rare in the western

half of the country (NPWS, 2015b).

Other habitats within Galway Bay SAC are shingle and stony beaches which are sparsely vegetated. Where

plant communities occur, they are characterised by species of disturbed maritime habitats including Curled Dock

Rumex crispus, Common Couch Elymus repens, Sea Sandwort Honkenya peploides, Sea Beet Beta vulgaris subsp.

maritima, Sea Mayweed Matricaria maritima (NPWS, 2015b).

A range of lagoons of varying types, sizes and salinities occur within the SAC with different underlying rock

types. Numerous lagoonal specialist species have been recorded across the SAC with many species recorded

being classed as rare and consequently the lagoons are classed as being of high conservation importance

(NPWS, 2015b).

In addition to marine habitats, the SAC contains terrestrial habitats of high conservation importance including

alkaline and Caladium fen, turloughs, limestone pavement, calcareous grassland, scrub formations, wet grassland

and deciduous woodland (NPWS, 2015b).

Important faunal species associated with the SAC include Common Seal and numerous bird species. Bird records

document Great Northern Divers, Black-throated Divers, Scaup, Long-tailed Duck and Red-breasted Merganser

as being present on site. The SAC is internationally important for Brent Goose populations. The site also supports

an important Common Seal colony and a breeding Otter population (NPWS, 2015b).


Table 4-7 Qualifying Interests of Galway Bay Complex SAC (000268)


1140 Mudflats and sandflats

not covered by

seawater at low tide

- Habitat area

- Community distribution

1150 Coastal Lagoons - Habitat area


- Salinity regime


- Barrier connectivity: between lagoon and sea

- Water quality: Chlorophyll a, Molybdate Reactive Phosphorous (MRP), Dissolved

Inorganic Nitrogen (DIN)

- Depth of marcophyte colonisation

- Typical plant species

- Typical animal species





1160 Large Shallow Inlets

and Bays

- Habitat area

- Community extent

- Community structure: Zostera density

- Community distribution

1170 Reefs - Distribution

- Habitat area

- Community extent

- Community structure: Mytilus density

1220 Perennial Vegetation

of Stony Banks

- Habitat area


- Physical structure: functionality and sediment supply

- Vegetation structure: zonation

- Vegetation composition: typical species and sub-communities, negative indicator

species

1310 (Salicornia) and other

annuals colonizing mud

and sand

- Habitat area


- Physical structure: sediment supply, creeks and pans, flooding regime

- Vegetation structure: zonation, vegetation height, vegetation cover, negative indicator

species Spartina anglica

- Vegetation composition: typical species and sub communities

1330 Atlantic salt meadows

(Glauco-Puccinellietalia

maritimae)

1410 Mediterranean salt

meadows (Juncetalia

maritimi)




area

- Soil type: area










5130 Juniperus communis

formations on heaths

or calcareous

grasslands

- Habitat area


- Juniper population size

- Formation structure: cover and height, community diversity and extent, cone-bearing

plants, seedling recruitment, dead plants

- Vegetation composition: typical species, negative indicator species




6210 Semi-natural dry

grasslands and

scrubland facies on

calcareous substrates

(Festuco Brometalia)

(*important orchid

sites

- Habitat area


- Vegetation composition; broadleaf herb:grass ratio, typical species, negative

indicator species

- Vegetation structure: sward height, woody species and bracken


7210 Calcareous fens with

(Cladium mariscus)

and species of the


- Habitat area



- Peat formation




7230 Alkaline Fens




- Extent of freshwater habitat (river)





1365 Common (Harbour)

Seal Phoca vitulina

- Access to suitable habitat

- Breeding behaviour

- Moulting behaviour

- Resting behaviour

- Disturbance


The site-specific Conservation Objectives for Galway Bay Complex SAC (NPWS, 2013o) are as follows:

▪ To maintain the favourable conservation condition of Mudflats and sandflats not covered

by seawater at low tide in Galway Bay Complex SAC.

▪ To restore the favourable conservation condition of Coastal lagoons in Galway Bay

Complex SAC.

▪ To maintain the favourable conservation condition of Large shallow inlets and bays in

Galway Bay Complex SAC.

▪ To maintain the favourable conservation condition of Reefs in Galway Bay Complex SAC.

▪ To maintain the favourable conservation condition of Perennial vegetation of stony banks

in Galway Bay Complex SAC.

▪ To maintain the favourable conservation condition of Salicornia and other annuals

colonizing mud and sand in Galway Bay Complex SAC.

▪ To restore the favourable conservation condition of Atlantic salt meadows

(GlaucoPuccinellietalia maritimae) in Galway Bay Complex SAC.



▪ To restore the favourable conservation condition of Mediterranean salt meadows

(Juncetalia maritimi) in Galway Bay Complex SAC.

▪ To maintain the favourable conservation condition of Turloughs in Galway Bay Complex

SAC.

▪ To restore the favourable conservation condition of Juniperus communis formations on

heaths or calcareous grasslands in Galway Bay Complex SAC.

▪ To maintain the favourable conservation condition of Semi-natural dry grasslands and

scrubland facies on calcareous substrates (Festuco Brometalia) in Galway Bay Complex

SAC.

▪ To maintain the favourable conservation condition of Calcareous fens with Cladium

mariscus and species of the Caricion davallianae in Galway Bay Complex SAC.

▪ To maintain the favourable conservation condition of Alkaline fens in Galway Bay

Complex SAC.

▪ To restore the favourable conservation condition of Otter in Galway Bay Complex SAC.

▪ To maintain the favourable conservation condition of Harbour Seal in Galway Bay

Complex SAC.

Favourable conservation condition is defined by a series of attributes and targets, which are defined on a

habitat/species basis. The attributes for each habitat/species are detailed in Table 4-7 above.


Background data from the Natura 2000 Data Form for Galway Bay Complex SAC (2017f) identifies that the

site is vulnerable to:

▪ Sewage effluent and detritus from aquaculture industry could have a negative effect on

benthic communities.

▪ Compaction of reefs from tractors accessing oyster trestles.

▪ Over-fishing.

▪ Maerl extraction.

▪ Eutrophication of lagoon areas.

▪ Drainage to fen and turlough habitats.

▪ Disturbance to bird populations from aquaculture activities.

▪ Agriculture intensirication

▪ Sand and gravel extraction and removal of beach materials

▪ Slipways and industrial ports

▪ Disposal of inert materials

▪ Invasive non-native species

▪ Reclamation of land from sea, estuary or marsh, modification of water flow, sea defense

or coast protection works, tidal barrages.

4.9 Greaghans Turlough SAC (000503)

Greaghans Turlough is a group of five turloughs, which has a flat, oval, deepest at its northern edge. It is an

undrained turlough with variety of well-developed vegetation communities. The area surrounding the turlough is

grazed. The SAC habitat contains two streams (one of which is permanent and one of which is ephemeral),

woodland and various types of grassland (NPWS, 2013h).



There are numerous plant species associated with the turlough including Amphibious Bistort

Polygonum amphibium, Common Sedge Carex nigra, Jointed Rush Juncus articulatus and Lesser Spearwort

Ranunculus flammula. The habitat surrounding the turlough is predominantly grassland which is highly nutrient-

enriched and consequently species-poor. The turlough basin is regularly trampled by cattle in places, and

therefore, the vegetation consists of annual or short-lived perennial species such as Water-pepper Polygonum

hydropiper, Redshank Polygonum persicaria, Common Chickweed Stellaria media, Thread-leaved Water-

crowfoot Ranunculus trichophyllus, Marsh Foxtail Alopecurus geniculatus and the rare, Red Data Book species,

Northern Yellowcress Rorippa islandica. Located on the northern side of the SAC are areas of woodland which

contain Ash Fraxinus excelsior, Hawthorn Crataegus monogyna and Spindle Euonymus europaeus (NPWS,

2013h).

The site is notable for its use by winter swans, with approximately 40 Whooper Swans being previously recorded

(NPWS, 2013i).


Table 4-8 Qualifying Interests of Greaghans Turlough SAC (000503)





area

- Soil type: area












The Conservation Objective for Greaghans Turlough SAC is to maintain or restore the favourable conservation


4-8) (NPWS, 2018d).



Background data from the Natura 2000 Data Form for Greaghans Turlough SAC (2017g) identifies that the site

is vulnerable to:

▪ Diffuse pollution to surface waters due to agricultural and forestry activities

▪ Agricultural activities such as grazing, stock feeding and fertilisation.



4.10 Kilglassan/Caheravoostia Turlough Complex SAC (000504)

The SAC consists of two turloughs separated by a rise in the land. The generally topography of the site is rolling

hills with a limestone outcrop at the northern end. The two turloughs are wet yearround and have accumulated

peat which in places has not been cut for over 20 years (NPWS, 2013i).

There are numerous vegetation communities found within this SAC due to the wetter nature of the turloughs. There

are large areas of Amphibious Bistort Polygonum amphibium and Common Sedge Carex nigra present at lower

levels, with Bogbean Menyanthes trifoliata, Purple Moor-grass Molinia caerulea and Marsh Pennywort

Hydrocotyle vulgaris present on the peat top. Mat grass Nardus stricta is found on the basin sides. Situated within

the turlough are several small ponds which contain Great Yellow-cress Rorippa amphibia, Unbranched Bur-reed

Sparganium emersum and Hemlock Water-dropwort Oenanthe aquatica (NPWS, 2013i).

The high level divide between the two turlough areas comprises of Lesser Tussock-sedge Carex diandra, Knotted

Pearlwort Sagina nodosa and Small Sweet-grass Glyceria declinata. Other habitats present across the site

include areas of improved grassland and scrub (NPWS, 2013i).

Due to the topography of the site and year-round retained water levels, the site provides excellent habitats for

wading birds, with Lapwing, Snipe and Redshank (NPWS, 2013i).


Table 4-9 Qualifying Interests of Kilglassan/Caheravoostia Turlough Complex SAC (000504)





area

- Soil type: area












The Conservation Objective for Kilglassan/Caheravoostia Turlough Complex SAC is to maintain or restore the

favourable conservation condition of the Annex I habitat(s) and/or the Annex II species for which the SAC has

been selected (see Table 4-9) (NPWS, 2018f).



Background data from the Natura 2000 Data Form for Kilglassan/Caheravoostia Turlough Complex SAC

(2017h) identifies that the site is vulnerable to:

▪ Agricultural intensification.



▪ Diffuse and groundwater pollution.

4.11 Levally Lough SAC (000295)

Levally Lough is a fluctuating lake which contains numerous habitats including areas of peaty grassland, species-

poor grassland an oligotrophic lake (NPWS, 2013j).

The peat grassland is located along the southern shore and Creeping Willow Salix repens and Purple Moor-

grass Molinia caerulea are widespread. The eastern and western ends of the turlough are dominated by

Amphibious Bistort Polygonum amphibium and Silverweed Potentilla anserina. The main body of the lake contains

vegetation adapted to oligotrophic conditions with Shoreweed Littorella uniflora and Stoneworts Chara spp.,

including C. curta present. However, the centre of the lake has become invaded by Common Reed Phragmites

australis, Bogbean Menyanthes trifoliata and Rusty Willow Salix cinerea subsp. Oleifolia (NPWS, 2013j).

Due to the year-round presence of water at the site, wildfowl are present in large numbers, during both summer

and winter periods (NPWS, 2013j).


Table 4-10 Qualifying Interests of Levally Lough SAC (000295)





area

- Soil type: area












The Conservation Objective for Levally Lough SAC is to maintain or restore the favourable conservation condition

of the Annex I habitat(s) and/or the Annex II species for which the SAC has been selected (see Table 4-10)

(NPWS, 2018g).



Background data from the Natura 2000 Data Form for Levally Lough SAC (2014i) identifies that the site is

vulnerable to:

▪ Sand and gravel quarries



4.12 Lisnageeragh Bog and Ballinastack Turlough SAC (000296)

This site is classed as an active raised bog and is therefore peat-forming and in good condition, especially on

the western side of the SAC. It contains a number of micro-habitats associated with wet, peat-forming bog

environments, including well-developed hummocks, pools, wet flats, Sphagnum lawns, flushes and soaks. Some

areas of the bog have, however, become degraded sue to drainage activities and peat cutting (NPWS, 2017x).

Rhynchosporion habitat is another characteristic feature of the site, within the active raised bog and is found in

wet depressions, pool edges and erosion channels. Vegetation covers within these areas consists of White Beak-

sedge Rhynchospora alba and/or Brown Beak-sedge R. fusca. Bog Asphodel Narthecium ossifragum, sundews

Drosera spp. and Carnation Sedge Carex panicea are also present, but less dominant (NPWS, 2017x).

The degraded bog habitat is dominated by species which are adapted to a slightly drier environment due to

the influences of external drainage. These include Heather Calluna vulgaris,

Bog Asphodel, Hare’s-tail Cotton-grass Eriophorum vaginatum, Deergrass and Carnation Sedge. An extensive

area of cut-over peat bog is present in the south-west (NPWS, 2017x).

Located in the north of the site is Ballinastack Turlough which borders the raised bog habitat. The turlough is

supplied by groundwater, but unusually, contains peat deposits. The vegetation is dominated by Common Sedge

Carex nigra. The turlough environment provides excellent habitat for wintering wildfowl. Greenland White-

fronted Goose, Whooper Swan and Golden Plover are all present in large numbers (NPWS, 2017x).


Table 4-11 Qualifying Interests of Lisnageeragh Bog and Ballinastack Turlough SAC (000296)





area

- Soil type: area










7110 Active raised bogs - Habitat area


- High bog area

- Hydrological regime: water levels, flow patterns

- Transitional areas between high bog and adjacent mineral soils

- Vegetation quality: central ecotope, active flush, soaks, bog woodland,

microtopographical features, bog moss (Sphanum) species

- Typical ARB species: flora, fauna

- Elements of local distinctiveness

- Negative physical indicators

- Vegetation composition: native negative indicator species, non-native invasive species

7120 Degraded raised

bogs still capable of

natural

regeneration


substrates of the

Rhynchosporion



- Air quality: nitrogen deposition

- Water quality


The Conservation Objective for Lisnageeragh Bog and Ballinastack Turlough SAC is to maintain or restore the


been selected (see Table 4-11) (NPWS, 2016a).



Background data from the Natura 2000 Data Form for Lisnageeragh Bog and Ballinastack Turlough SAC (2017j)

identifies that the site is vulnerable to:

▪ Agricultural activities such as grazing and use of fertaliser

▪ Mechanical removal of peat

▪ Invasive non-native species and problematic native species

▪ Human induced changes in hydraulic conditions

4.13 Lough Carra/Mask Complex SAC (001774)

This SAC contains two large lakes; Lough Mask and Lough Carra, along with the smaller Cloon Lough. All of them

have a similar underlying geology causing the diversity of habitats present within the site (NPWS, 2015c).

Lough Mask is one of the largest and deepest lakes in Ireland and is classed as a lowland oligotrophic lake. A

number of aquatic and wetland species are present including several pondweed species Potamogeton spp.,

Water Lobelia Lobelia dortmanna and Shoreweed Littorella uniflora. Part of the eastern shoreline is limestone

based with vegetation communities which reflect this underlying geology, with a combination of bare pavement,

scrub-dominated pavement, dry grassland and heath present. Along the eastern and southern shores, significant

areas are covered by deciduous woodland. The western side of the lake is joined by the Owenbrin River which

has resulted in a delta of coarse sandy sediment forming (NPWS, 2015c).

In contrast Lough Carra is classed as a hard water marl lake, and is mainly shallow. It is springfed and only has

a few small streams flowing into it. Stonewort communities are present with Chara curta, C. desmacantha, C. rudis

and C. contraria recorded. The eastern and southern shores of the lake contain a complex of limestone and

wetland habitats. The limestone pavement within this area is variable in character and contains areas of dense

scrub and bare ground. Calcareous grassland is also present which is orchid-rich and contains species including

Pyramidal Orchid Anacamptis pyramidalis, Early-purple Orchid Orchis mascula, Bee Orchid Ophrys apifera,

Fragrant Orchid Gymnodenia conopsea and Dense-flowered Orchid Neotinea maculata (NPWS, 2015c).

Other habitats present within the SAC include dry heath and alkaline and Cladium fen. Alkaline fen is more

extensive across the site than Cladium fen with Black Bog-rush Schoenus nigricans being the dominant species.

There are also sparse but widespread reed swamps, wet grassland and some freshwater marsh communities

around the lake shores. Broad-leaved woodland is also present which is often scrub-type habitat which may be

dominated by wither wet or dry species. Wet areas of woodland are prone to seasonal flooding and alluvial

woodland is listed on Annex 1 as a priority habitat (NPWS, 2015c).



A number of rare plants are found in the SAC including Irish St. John's-wort Hypericum canadense, Chives Allium

schoenoprasum, Pillwort Pilularia globulifera, Irish Lady's-tresses Spiranthes romanzoffiana and Small Cudweed

Logfia minima (NPWS, 2015c).

Faunal species present on site include Lesser Horseshoe Bat which are known to occupy a breeding summer roost

in a stable building within the SAC. A second roost is present near Ballykyne and consequently the site is of

international importance for this species. Otter, Pine Martin Martes and breeding birds are also present.

Greenland White-fronted Goose use the site for over wintering with a large diversity of wildfowl species also

occupying the site. Lough Mask is home to Arctic Char Salvelinus alpinus and a rare shrimp Niphargus spp. It also

contains a Brown Trout fishery and White-clawed crayfish Austropotamobius pallipes are present in its waters

(NPWS, 2015c).


Table 4-12 Qualifying Interests of Lough Carra/Mask Complex SAC (001774)



containing very few

minerals of sandy plains

(Littorelletalia uniflorae)

- Habitat area


- Typical species



- Hydrological regime: water level fluctioations





- Water colour


- Turbidity

- Fringing habitat

From: Connemara Bog Complex SAC Conservation Objectives (002034) (NPWS,

2015g)

3130 Oligotrophic to

mesotrophic standing

waters with vegetation

of the Littorelletea

uniflorae and/or Isoeto-

Nanojuncetea

3140 Hard oligo-

mesotrophic waters with

benthic vegetation of

Chara spp

4030 European dry heaths - Habitat area




- Vegetation composititon: number of positive indicator species, lichens and

bryophytes, cover of positive indicator species, negative indicator species, non-

native species, native tree and shrubs, bracken, soft rush

- Vegetation structure: ling, signs of browsing, burning, dwarf shrub composition,

growth phase of ling, disturbed bare ground, Indicators of local distinctiveness

From: Connemara Bog Complex SAC Conservation Objectives (002034) (NPWS,

2015g)

6210 Semi-natural dry

grasslands and

scrubland facies on



(*important orchid sites)

- Habitat area


- Vegetation composition; broadleaf herb:grass ratio, typical species, negative

indicator species

- Vegetation structure: sward height, woody species and bracken






7210 Calcareous fens with

Cladium mariscus and

species of the Caricion

davallianae

- Habitat area



- Peat formation





7230 Alkaline Fens

8240 Limestone Pavement There are no Site-Specific Conservation Objectives for limestone pavement available

which could have been used in this assessment. As a result, the following attributes have

been proposed based on Ryan Hanley (2014c). - Habitat area


- Vegetation composition: typical species, notable species

91E0 Alluvial forests with Alnus

glutinosa and Fraxinus

excelsior (Alno-Padion,

Alnion incanae, Salicion

albae)

- Habitat area


- Woodland size


regeneration, dead wood, veteran trees, indicators of local distinctiveness

- Hydrological regime: flooding depth/height of water table

- Vegetation composition: native tree cover, typical species, negative indicator

species

From: Lower River Shannon SAC Conservation Objectives (NPWS, 2012a)

1303 Lesser Horseshoe Bat

Rhinolophus hipposideros


- Winter roosts

- Summer roosts




- Light pollution

From: Kenmare River SAC Conservation Objectives (NPWS, 2013l)

1355 Otter Lutra lutra - Distribution



- Extent of freshwater habitat (river)





- From: Galway Bay Complex SAC Conservation Objectives (NPWS, 2013o)

1393 Slender Green

Feather-moss

Drepanocladus vernicosus

There are no Site-Specific Conservation Objectives for this species available which

could have been used in this assessment. As a result, the following attributes have been

proposed based on professional judgement;

- Habitat area

- Population size

- Area occupied by habitat




The Conservation Objective for Lough Carra/Mask Complex SAC is to maintain or restore the favourable

conservation condition of the Annex I habitat(s) and/or the Annex II species for which the SAC has been selected

(see Table 4-12) (NPWS, 2018c).



Background data from the Natura 2000 Data Form for Lough Carra/Mask Complex SAC (2017k) identifies that

the site is vulnerable to:

▪ Abandonment/ lack of mowing.

▪ Pollution to surface waters

4.14 Lough Corrib SAC (000297)

Lough Corrib is the second largest lake in Ireland. It can be divided into two parts; a relatively shallow basin

underlain by Carboniferous Limestone in the south and a larger, deeper basin on more acidic rocks in the north.

The northern basin also contains the rare species Slender Naiad which is listed on the Flora (Protection) Order

1999. To the south and east surrounding land is dominated by pastoral farming, with bog and heath habitats in

the north and west (NPWS, 2015d).

Around the margins of the lake large areas of reedswamp are present dominated by varying mixtures of

Common Reed Phragmites australis and Common Club-rush Schoenoplectus lacustris. These reedswamp areas

grade into species-rich marsh vegetation containing a broad range of plant species. The Great Fen-sedge

Cladium mariscus fen areas are of particular interest and these have developed in the sheltered bays,

particularly in the south-east corner of the lake. Alkaline fens are also present and more widespread than the

Cladium fens and wet meadows dominated by Purple Moor-grass Molinia caerulea also occur in seasonally

flooded areas (NPWS, 2015d).

The designation contains a number of rivers including the Clare, Grange, Bealanabrack, Failmore, Cornamona,

Drimeen and Owenriff. Many of the rivers in the SAC support submerged and floating vegetation of the

Ranunculion fluitantis and Callitrichio-Batrachion type, including moss dominated communities (NPWS, 2015d).

In addition to the lake and riverine habitats, a range of other habitat types are present including raised bog,

with associated hummock and bog pool habitats in four areas (Addergoole, Slieve Bog, Lough Tee Bog and

Killaclogher Bog), oak woodland on the Hill of Doon, grassland which is orchidrich and associated with limestone

exposures and limestone pavement along much of the shoreline in the lower Corrib basin (NPWS, 2015d).

The rare species Slender Green Feather-moss Drepanocladus vernicosus is also present in a fen at Gortachalla,

north-east of Moycullen. At this location it is widespread around the margins and is a significant population in a

national context (NPWS, 2015d).

The fauna of the site is also important. The lake is internationally important for waterfowl, with important

populations of Pochard, Coot, Mute Swan, Tufted Duck, Cormorant and Greenland White-fronted Goose. Otter

and Irish Hare are also regularly recorded. Atlantic Salmon use the lake and rivers and spawning grounds and

the very good Trout populations are also present. There are also populations of Sea Lamprey, Brook Lamprey,

Lesser Horseshoe Bat, White-clawed Crayfish and Freshwater Pearl Mussel (NPWS, 2015d).




Table 4-13 Qualifying Interests of Lough Corrib SAC (000297)



containing very few minerals

of sandy plains (Littorelletalia

uniflorae)

- Habitat area


- Typical species








- Water colour


- Turbidity

- Fringing habitat: area and condition

3130 Oligotrophic to mesotrophic

standing waters with

vegetation of the

Littorelletea uniflorae

and/or Isoeto-Nanojuncetea

3140 Hard oligo-mesotrophic

waters with benthic

vegetation of Chara spp.

3260 Water courses of plain to

montane levels with the

Ranunculion fluitantis and

CallitrichoBatrachion

- Habitat area


- Hydrological regime: river flow, groundwater discharge

- Substratum composition: particle size range

- Water quality

- Vegetation composition: typical species

- Floodplain connectivity

- Riparian habitat

6210 Semi-natural dry grasslands

and scrubland facies on




- Habitat area


- Vegetation composition: broadleaf herb:grass ratio, typical species, negative

indicator species, non-native species, woody species and bracken

- Vegetation structure: broadleaf herb:grass ratio, sward height, litter

- Physical structure: percentage bare soil, distturbance

6410 Molinia meadows on

calcareous, peaty or clavey-

silt-laden soils (Molinion

caeruleae)

- Habitat area


- Vegetation structure: woody species and bracken, broadleaf herb:grass ratio,

sward height, litter

- Vegetation composition: typical species, negative indicator species, non-native

species, moss species

- Vegetation structure: woody species and bracken

- Physical structure: bare soil, disturbance



- High bog area


- Transitional areas between high bog and adjacent mineral soils (including

cutover areas)

7120 Degraded raised bogs still

capable of natural

regeneration





substrates of the

Rhynchosporion


microtopographical features, bog moss (Sphagnum) species




- Vegetation composition: native negative indicator species, non-native invasive

species

- Air quality

- Water quality

7210 Calcareous fens with Cladium

mariscus and species of the


- Habitat area


- Ecosystem function: hydrology, peat formation, water quality

- Vegetation structure: typical species

- Vegetation composition: non-native species, trees and shrubs



7220 Petrifying springs with tufa

formation

(Cratoneurion)

- Habitat area


- Hydrological regime: height of water table, water flow

- Water quality: nitrate level, phosphate level

- Vegetation composition: positive indicator species, negative indicator species

- Vegetation structure: sward height

- Physical structure: trampling/dung

7230 Alkaline Fens - Habitat area


- Ecosystem function: soil nutrients, peat formation, hydrology, water quality


- Vegetation composition: number of positive indicator species (brown moss,

vascular plants), cover of positive indicator species, negative indicator species,

non-native species, native trees and shrubs, soft rush and common reed cover


- Physical structure: disturbed bare ground, drainage, tufa formations


8240 Limestone Pavement - Habitat area


- Vegetation composition: typical species, bryophyte layer, negative indicator

species, non-native species, scrub, bracken cover

- Vegetation structure: woodland canopy, dead wood

- Physical structre: disturbance


91A0 Old sessile oak woods with

Ilex and Blechnum in British

Isles

- Habitat area


- Woodland size


regeneration, dead wood, veteran trees, indicators of local distinctiveness

- Vegetation composition: native tree cover, typical species, negative indicator

species




91D0 Bog Woodland - Habitat area


- Vegetation composition: positive indicator species, negative indicator species

- Woodland structure: cover and height, dwarf shrub cover, ling cover,

bryophyte cover, tree size classes, senescent and dead wood

1029 Freshwater Pearl Mussel

Margaritifera margaritifera

- Distribution

- Population size

- Population structure: recruitment, adult mortality

- Habitat extent and condition

- Water quality: macroinvertebrate and phytobenthos (diatoms)

- Substratum quality: filamentous algae (macroalgae), macrophytes (rooted

higher plants), sediment, oxygen availability

- Hydrological regime: flow variability

- Host fish

- Fringing habitat area and condition

1092 White-clawed Crayfish

Austropotamobius

pallipes

- Distribution

- Population structure: recruitment


- Disease

- Water quality

- Habitat Quality: heterogeneity

1095 Sea Lamprey Petromyzon

marinus

- Distribution: extent of anadromy

- Population structure of juveniles

- Juvenile density in fine sediment

- Extent and distribution of spawning habitat

- Availability of juvenile habitat

1096 Brook Lamprey Lampetra

planeri

1106 Salmon Salmo salar - Distribution: extent of anadromy





- Water quality

1303 Lesser horseshoe bat

Rhinolophus hipposideros


- Summer roosts

- Number of auxillary roosts



- Light pollution




- Extent of freshwater (river) habitat








1393 Slender Green Feather-moss


- Distribution of populations

- Population size

- Population cover

- Area of suitable habitat

- Hydrological conditions: water table level

- Vegetation composition: tree cover, shrub cover, grass cover, bryophyte cover,

cover of Calliergonella cuspidate


1833 Slender Naiad Najas

flexilis

- Population extent

- Population depth




- Habitat extent



- Water quality


- Water colour

- Associated species



The Conservation Objectives for Lough Corrib SAC (2017ac) are:

▪ To resore the favourable conservation condition of Oligotrophic waters containing very few minerals

of sandy plains (Littorelletalia uniflorae) in Lough Corrib SAC

▪ To restore the favourable conservation condition of Oligotrophic to mesotrophic standing waters

with vegetation of the Littorelletea uniflorae and/or Isoëto-Nanojuncetea in Lough Corrib SAC

▪ To restore the favourable conservation condition of Hard oligo-mesotrophic waters with benthic

vegetation of Chara spp. in Lough Corrib SAC,

▪ To maintain the favourable conservation condition of Water courses of plain to montane levels

with the Ranunculion fluitantis and Callitricho-Batrachion vegetation in Lough Corrib SAC

▪ To maintain the favourable conservation condition of Semi-natural dry grasslands and scrubland

facies on calcareous substrates (Festuco-Brometalia) (* important orchid sites) in Lough Corrib

SAC

▪ To maintain the favourable conservation condition of Molinia meadows on calcareous, peaty or

clayey-silt-laden soils (Molinion caeruleae) in Lough Corrib SAC

▪ To restore the favourable conservation condition of Active raised bogs* in Lough Corrib SAC

▪ To maintain the favourable conservation condition of Calcareous fens with Cladium mariscus and

species of the Caricion davallianae in Lough Corrib SAC

▪ To maintain the favourable conservation condition of Petrifying springs with tufa formation

(Cratoneurion)* in Lough Corrib SAC

▪ To maintain the favourable conservation condition of Alkaline fens in Lough Corrib SAC

▪ To maintain the favourable conservation condition of Limestone pavements* in Lough Corrib SAC



▪ To maintain the favourable conservation condition of Old sessile oak woods with Ilex and

Blechnum in the British Isles in Lough Corrib SAC

▪ To maintain the favourable conservation condition of Bog woodland* in Lough Corrib SAC

▪ To restore the favourable conservation condition of Freshwater Pearl Mussel in Lough Corrib SAC

▪ To maintain the favourable conservation condition of White-clawed Crayfish in Lough Corrib

SAC

▪ To maintain the favourable conservation condition of Brook Lamprey in Lough Corrib SAC

▪ To restore the favourable conservation condition of Sea Lamprey in Lough Corrib SAC

▪ To maintain the favourable conservation condition of Atlantic Salmon in Lough Corrib SAC

▪ To restore the favourable conservation condition of Lesser Horseshoe Bat in Lough Corrib SAC

▪ To maintain the favourable conservation condition of Otter in Lough Corrib SAC

▪ To maintain the favourable conservation condition of Slender Green Feather-moss (Shining

Sickle-moss) in Lough Corrib SAC

▪ To restore the favourable conservation condition of Slender Naiad in Lough Corrib SAC



Background data from the Natura 2000 Data Form for Lough Corrib SAC (2017l) identifies that the site is

vulnerable to:

▪ Uncontrolled discharge of sewage.

▪ Seasonal disturbance form shooting.

▪ Fishing activities.

▪ Suburbanisation form holiday home developments which may affect water quality.

▪ Continued peat cutting.

▪ Forest planting on open ground

▪ Sand and gravel quarries and underground mining

▪ Disposal of household/recreational facility waste

4.15 Lough Lurgeen Bog/ Glenamaddy Turlough SAC (000301)

This SAC consists of a large turlough (170ha in extent) and an expanse of typical, intact, western raised bog

(1000ha). A small lake also occurs at the top of the bog, which is fed by water from the bog and in turn is linked

to the turlough. The three habitat types are therefore closely associated with each other and result in a unique

ecosystem, which is also important for waterfowl (NPWS, 2015e).

The raised bog is, for the most part, classified as degraded bog, with a rather flat surface. Vegetation present

includes Heather Calluna vulgaris, Hare's-tail Cotton-grass Eriophorum vaginatum, Cross-leaved Heath Erica

tetralix and Carnation Sedge Carex panicea, amongst others. Bog moss Sphagnum spp. cover is also low,

typically less than 30% ground cover (NPWS, 2015e).

Wet pool systems dominated by Rhynchosporion vegetation are also present throughout the high bog area,

along with extensive quaking lawns dominated by White Beak-sedge Rhynchospora aba. The lake within the

bog habitat is oligotrophic in nature (NPWS, 2015e).

Glenamaddy Turlough has extensive areas of uniform vegetation, consisting of large stands of peat grassland

dominated by Common Sedge Carex nigra and Amphibious Bistort Persicaria amphibia. The rare Fen Violet



Viola persicifolia is also present within the turlough. Three watercourses flow into the turlough, the largest from

Lurgeen Bog. A well-defined swallow hole also occurs in the north-west corner (NPWS, 2015e).


Table 4-14 Qualifying Interests of Lough Lurgeen Bog/ Glenamaddy Turlough SAC (000301)




- Hydrological regime: flood duration, frequency area, depth, permanently flooded area

- Soil type: area










3270 Rivers with muddy

banks with

Chenopodion rubric

p.p. and Bidention

p.p. vegitation

- Habitat area


- Hydrological regime: flood duration, frequency, area, depth; permanently flooded area

- Soil type

- Soil nutrient status

- Physical structure

- Chemical processes

- Water quality


- Typical species

- Fringing habitats



- High bog area


- Transitional areas between high bog and adjacent mineral soils (including cutover areas)






- Vegetation composition: native negative indicator species, non-native invasive species

- Air quality

- Water quality

7120 Degraded raised

bogs still capable

of natural

regeneration


substrates of the

Rhynchosporion




The Conservation Objective for Lough Lurgeen Bog/ Glenamaddy Turlough SAC is to maintain or restore the


been selected (see Table 4-14) (NPWS, 2016o). Section 4.2.2 above details the criteria used to assess

favourable condition.


Background data from the Natura 2000 Data Form for Lough Lurgeen Bog/ Glenamaddy Turlough SAC (2017m)

identifies that the site is vulnerable to:

▪ External drainage of the raised bog leading to increased water run-off.

▪ Peat cutting.

▪ Burning.

▪ Water pollution within the turlough.

▪ External drainage within the turlough.

▪ Eutrophication from sewage outfall within turlough.

4.16 Maumturk Mountains SAC (002008)

The Maumturk Mountains are bounded to the north by Killary Harbour and to the south by the Galway/Clifden

Road. Most of the mountains in this SAC exceed 600m in height and many rivers are located within it. A range

of habitat types are found within the site, and within the variety of habitats a number of rare species are present,

including Slender Naiad Najas flexilis, Slender Cotton-grass Eriophorum gracile and Purple Saxifrage Saxifraga

oppositifolia (NPWS, 2013k).

Wet heath is widespread within the site and is located around the margins of blanket bog and on the lower

slopes where peat depth is less than 1m. Vegetation in the wet heath areas is typically dominated by Purple

Moor-grass Molinia caerulea, with Cross-leaved Heath Erica tetralix and Heather Calluna vulgaris sub-dominant.

On the drier, steeper slopes dry heath is present with Bell Heather Erica cinerea the frequent species (NPWS,

2013k).

Blanket bog also occurs within the site, and is generally of good quality, particularly at Caher. Features within

the blanket bog include hummocks of the bog mosses Sphagnum fuscum and S. imbricatum and flushes with Bog

Pondweed Potamogeton polygonifolius, rushes and various sedges. The scarce Brown Beak-sedge Rhynchospora

fusca is also common in the surrounding bog (NPWS, 2013k).

Oligotrophic lakes are also frequent, mainly occurring in the south-east near Maam Cross. Typical species include

Quillwork Isoetes lacustris, Pipework Eriocaulon aquaticum, Water Lobelia Lobelia dortmanna, Shoreweed

Littorella uniflora and Alternate Water-milfoil Myriophyllum alterniflorum (NPWS, 2013k).

Notable fauna within the site include Salmon, particularly in the Bealnabrack system, Arctic Char in Derrynean

Lough and Lough Shindilla and Irish Hare which is widespread throughout (NPWS, 2013k).




Table 4-15 Qualifying Interests of Maumturk Mountains SAC (002008)



containing very few

minerals of sandy

plains (Littorelletalia

uniflorae)

- Habitat area


- Typical species








- Water colour


- Turbidity


4010 Northern Atlantic

wet heaths with Erica

tetralix

- Habitat area




- Vegetation composititon: cross-leaved heath, positive indicator species, lichens and

bryophytes, ericoid species and crowberry, dwarf shrub species, negative indicator

species, non-native species, native tree and shrubs, bracken, soft rush



- Indicators of local distictivness

4060 Alpine and Boreal

heaths

- Habitat area




- Vegetation composititon: positive indicator species, lichens and bryophytes, ericoid

species and crowberry, dwarf shrub species, negative indicator species, signs of

grazing, signs of browsing, burning


- Physical structure: disturbed bare ground

- Indicators of local distictivness

7130 Blanket bog (*active

only)

- Habitat area


- Ecosystem function: soil nutrients, peat formations, hydrology


- Vegetation composition: positive indicator species, lichens and bryophytes, negative

indicator species, non-native species, native trees and shrubs

- Vegetation structure Sphagnum condition, signs of browsing, burning

- Physical structure: drainage, erosion, disturbed bare ground

- Indicators of local distinctveness


substrates of the

Rhynchosporion




8220 Siliceous rocky

slopes with

chasmophytic

vegetation

- Habitat area



- Vegetation composition: positive indicator species, non-native species, bracken, native

trees and shrubs

- Vegetation structure: grazing and browsing

- Indicators of local distinctveness

1106 Salmon Salmo salar - Distribution: extent of anadromy





- Water quality

1833 Slender naiad Najas

flexilis

- Population extent

- Population depth




- Habitat extent



- Water quality


- Water colour

- Associated species



The Conservation Objective for Maumturk Mountains SAC (2017y) are:

▪ To maintain the favourable conservation condition of Oligotrophic waters containing very

few minerals of sandy plains (Littorelletalia uniflorae) in Maumturk Mountains SAC

▪ To restore the favourable conservation condition of Northern Atlantic wet heaths with Erica

tetralix in Maumturk Mountains SAC

▪ To restore the favourable conservation condition of Alpine and Boreal heaths in Maumturk

Mountains SAC,

▪ To restore the favourable conservation condition of Blanket bogs (* if active bog) in


▪ To restore the favourable conservation condition of Depressions on peat substrates of the

Rhynchosporion in Maumturk Mountains SAC

▪ To restore the favourable conservation condition of Siliceous rocky slopes with

chasmophytic vegetation in Maumturk Mountains SAC

▪ To maintain the favourable conservation condition of Atlantic Salmon in Maumturk

Mountains SAC



▪ To maintain the favourable conservation condition of Slender Naiad in Maumturk

Mountains SAC


Background data from the Natura 2000 Data Form for Maumturk Mountains SAC (2017n) identifies that the site

is vulnerable to:

▪ Forest planting on open ground, planting of non-native trees

▪ Overgrazing by sheep.

▪ Peat extraction: hand cutting or mechanical

▪ Increased erosion of habitats.

▪ Reduction in water quality from peat in-wash and fertilisation from adjoining land.

4.17 Mocorha Lough SAC (001536)

Mocorha Lough SAC is a shallow wetland complex which lies in linear depression with Carboniferous limestone

running north-eastwards from Lough Corrib. Habitats present include fen, calcareous grassland, wet grassland

and Juniper Juniperus communis scrub (NPWS, 2013l).

The fen areas are dominated by Great Fen-sedge Cladium mariscus, which is one of the largest stands in the

west of the country. There are also areas of Black Bog-rush Schoenus nigricans dominated fen, dispersed across

the site, especially within the northern margins (NPWS, 2013l).

Calcareous grassland and heath vegetation is prevalent on higher ground within the centre of the site. Juniper is

abundant as is lack Bog-rush, Bell Heather Erica cinerea, Heather Calluna vulgaris, Crested Dog’s-tail Cynosurus

cristatus, Common Knapweed Centaurea nigra, Blue Moor-grass Sesleria albicans, Wild Thyme Thymus praecox

and Devil’s-bit Scabious Succisa pratensis (NPWS, 2013l).

The site is important locally for wetland birds with Snipe and Mallard present on site (NPWS, 2013l).


Table 4-16 Qualifying Interests of Mocorha Lough SAC (001536)


7210

Calcareous fens with

Cladium mariscus

and species of the


- Habitat area


- Ecosystem function: peat formation, hydrology- groundwater levels, surface water

flow, water quality

- Vegetation composition: typical species, native negative indicator species, non-native

species, trees and shrubs

- Physical structure: disturbed bare ground



The Conservation Objective for Mocorha Lough SAC is to maintain the favourable conservation condition of

Calcareous fens with Cladium mariscus and species of the Caricion davallianae* for which the SAC has been

selected (see Table 4-16) (NPWS, 2019b).





Background data from the Natura 2000 Data Form for Mocorha Lough SAC (2017o) identifies that the site is

vulnerable to:

▪ Disposal of household/ recreational facility waste

▪ Burning down existing vegetation

▪ Infilling of wetland habitats.

▪ High level of duck and snipe shooting across the site.

4.18 Monivea Bog SAC (002352)

Monivea Bog is an active raised bog which contains areas of high bog that are active. Typical micro-habitats

associated with active bogs are present including hummocks, pools, wet flats, Sphagnum lawns, flushes and soaks.

The bog dome features extensive examples of these features and even contains areas of quaking bog.

Associated vegetation with the active bog consists of Rhynchosporion habitat which occurs mainly in wet

depressions, pool edges and erosion channels. The vegetation is dominated by White Beak-sedge Rhynchospora

alba, Brown Beak-sedge R. fusca, and at least some Bog Asphodel Narthecium ossifragum, sundews Drosera spp.

and Carnation Sedge Carex panicea species (NPWS, 2014b).

The bog features a large soak-system in the north-west which originates at the lake. The open water is colonised

by Bottle Sedge Carex rostrata, Bogbean Menyanthes trifoliata, Soft Rush Juncus effusus and Marsh Cinquefoil

Potentilla palustris. To the south-east of the lake, this consists of a quaking mat of mosses Sphagnum cuspidatum,

S. recurvum, S. palustre and Aulacomnium palustre (NPWS, 2014b).

Degraded bog is present all around the margins of the high bog, where areas of peat have been adversely

affected by drainage and peat cutting activities. Evidence of extensive mechanical cutting is present to the north,

east and south of the site (NPWS, 2014b).


Table 4-17 Qualifying Interests of Monivea Bog SAC (002352)




- High bog area


- Transitional area between high bog and adjacent mineral soils






- Vegetation composition: native negative indicator species, non-native invasive

species

- Air quality: nitrogen deposition

- Water quality

7120 Degraded raised bogs

still capable of natural

regeneration


substrates of the

Rhynchosporion




The Conservation Objective for Monivea Bog SAC is to restore the favourable conservation condition of Active

raised bogs, degraded raised bogs still capable of natural regeneration and Depressions on peat substrates of

the Rhynchosporion for which the SAC has been selected (see Table 4-17) (NPWS, 2015f).



Background data from the Natura 2000 Data Form for Monivea Bog SAC (2017p) identifies that the site is

vulnerable to:

▪ Drying-out from peripheral peat cutting.

▪ Disposal of household/ recreational facility waste or inert materials


▪ Groundwater abstractions and other human enduced changes in hydraulic conditions

▪ Burning.

▪ Mechanisation of peat cutting.

▪ Afforestation.

4.19 Ross Lake and Woods SAC (001312)

The dominant habitat at this SAC is Ross Lake itself which is a medium-sized lake with a limestone bed, covered

by precipitated marl and limestone deposits. Therefore, it is a hard water lake and supports Stonewort species,

including Chara globularis var. virgata, C. pedunculata and C. curta. Areas of open water contain Yellow Water-

lily Nuphar lutea and Broad-leaved Pondweed Potamogeton natans (NPWS, 2013m).

The shoreline is dominated by wetland habitats which consists of reed swamp, freshwater marsh, fen, wet

woodland and wet grassland. The site also contains a coniferous plantation (Spruce Picea sp. dominated), and

there are also areas of broadleaved woodland and scrub present which are dominated by Beech Fagus

sylvatica, Ash Fraxinus excelsior or Hazel Corylus avellana species (NPWS, 2013m).

Fauanl species present include a breeding colony of Lesser Horseshoe Bat, which are present in an out-building

of Ross House. The surrounding habitat is optimal for foraging and commuting bats. Other notable species present

include Otter and a breeding colony of Common Gull (NPWS, 2013m).


Table 4-18 Qualifying Interests of Ross Lake and Woods SAC (001312)


3140 Hard oligo-

mesotrophic waters

with benthic

vegetation of Chara

spp.

- Habitat area


- Typical species








- Water colour

- Disolved organic carbon



- Turbidity

- Frining habitat

1303 Lesser horseshoe bat

Rhinolophus

hipposideros


- Summer roosts




- Light pollution


The Conservation Objective for Ross Lake and Woods SAC is to restore the favourable conservation conditions

of Lesser Horseshoe Bat Rhinolophus hipposideros and Hard oligo-mesotrophic waters with bentic vegetation of

Chara spp. for which the SAC has been selected (see Table 4-18) (NPWS, 2018k).



Background data from the Natura 2000 Data Form for Ross Lake and Woods SAC (2017q) identifies that the


▪ Agricultural intensification

▪ Sand and gravel extraction and mines


▪ Flooding

▪ Water pollution form surrounding agricultural and forestry activities.

▪ Disturbance or change of use of building would be detrimental to roosting bat

populations.

4.20 Shrule Turlough SAC (000525)

The turlough within this SAC is highly oligotrophic with thick marl and peat deposits. There is no above-ground

out-flow from the turlough, although several drainage attempts have been made previously via the enlargement

of swallow holes present. The site is no longer cut for peat, but cattle do graze the margins (NPWS, 2013n).

The turlough contains a high level of plant diversity with 18 plant communities present. Fen vegetation is extremely

well-developed with a large area dominated by Great Fen-sedge Cladium mariscus fen and Black Bog-rush

Schoenus nigricans fen. The site also contains plants which are not usually synonymous with turlough environments

including Whorled Water-milfoil Myriophyllum verticillatum, Least Bur-reed Sparganium minimum, Greater

Bladderwort Utricularia vulgaris and Creeping Yellow-Cress Rorippa sylvestris (NPWS, 2013n).

Lough Lee is located at the southern extent of the site and is surrounded by a mosaic of speciesrich wet grassland

and dry grassland with outcrops of limestone present (NWPS, 2013n).




Table 4-19 Qualifying Interests of Shrule Turlough SAC (000525)





area

- Soil type: area










From: Galway Bay Complex SAC Conservation Objective (NPWS, 2013o)


The Conservation Objective for Shrule Turlough SAC is to maintain or restore the favourable conservation


4-19) (NPWS, 2018l).



Background data from the Natura 2000 Data Form for Shrule Turlough SAC (2017r) identifies that the site is

vulnerable to:

▪ In-flow from the western end into the basin which could be a eutrophying influence.

▪ Agricultural run-off from farming.

▪ Effects of increased arterial drainage.

▪ Cattle grazing.

4.21 Towerhill House SAC (002179)

This site is important due to its Lesser Horseshoe Bat Rhinolophus hipposideros population. The bats use an

underground man-made passage which runs from the ruin of Towerhill House. The passage offers a winter roost

site for the species as it has a constant temperature throughout the winter (NPWS, 2014c).

The habitat surrounding the passageway contains a series of drains and streams which flow into Lough Beg and

a small lake which is surrounded by swamp vegetation and wet woodland. The lake system contains extensive

reed beds with stands of Greater Tussock-sedge Carex paniculata present. Wet woodland areas are dominated

by Downy Birch Betula pubescens, Alder Alnus glutinosa and Rusty Willow Salix cinerea subsp. Oleifolia. The

remainder of the site is composed of commercial coniferous forest (NPWS, 2014c).




Table 4-20 Qualifying Interests of Towerhill House SAC (002179)


1303 Lesser Horseshoe Bat Rhinolophus

hipposideros


- Winter roosts

- Summer roosts




- Light pollution


The Conservation Objective for Towerhill House SAC is to maintain the favourable conservation condition of Lesser

Horseshoe Bat Rhinolophus hipposideros for which the SAC has been selected (see Table 4-20) (NPWS, 2018m).



Background data from the Natura 2000 Data Form for Towerhill House SAC (2017s) identifies that the site is

vulnerable to:

▪ Commercial timber felling near roost entrance.

4.22 Williamstown Turloughs SAC (002296)

This site consists of a series of turloughs (Curragh, Polleagh and Gortduff), which lie within a complex of esker

ridges and raised and valley peats. It supports a good diversity of waterbirds, including Whooper Swan, Mute

Sawn, Mallard, Wigeon, Teal, Shoveler, Tufted Duck, Pochard, Golden Plover, Lapwing and Dunlin (NPWS,

2014d).

Polleagh turlough is oligotrophic with a permanent very shallow lake fed only by water from its surrounding small

catchment area. In times of high flood, the Polleagh Lough connects to Polleagh West, which almost dries out in

summer. This turlough has a particularly diverse vegetation community, with eleven true turlough communities

present. Reedbeds with Common Reed Phragmites australis and Common Club-rush Schoenoplectus lacustris cover

significant parts of the southern end. Marl pond vegetation, wet annual vegetation, sedge stands and a number

of specialist species are also present (NPWS, 2014d).

Curragh turlough is similar to Polleagh and is in hydraulic continuity. Vegetation is however, less diverse than at

Polleagh, with only five true turlough plant communities present. Pure stands of Amphibious Bistort Persicaria

amphibia with the moss Fontinalis antipyretica cover much of the small hollows and larger bays close to the lake

margins, with sedge grassland elsewhere (NPWS, 2014d).

Gortduff turlough is a small, well-grazed, elongated and undulating steep-sided turlough with a number of sink-

holes. It has a permanent pond at its south-eastern end and is dependent on a perched water-table. The

steEPsides should a good zonation from Amphibious Bistort at the base to a dry Common Sedge Carex nigra

community around the upper margins (NPWS, 2014d).




Table 4-21 Qualifying Interests of Williamstown Turloughs SAC (002296)




- Hydrological regime: groundwater contribution, flood duration, frequency area, depth,

permanently flooded/wet areas

- Soil type




- Water quality




- Typical species

- Fringing habitat


The Conservation Objective for Williamstown Turloughs SAC is to restore the favourable conservation condition

of Turloughs for which the SAC has been selected (see Table 4-21) (NPWS, 2018o).



Background data from the Natura 2000 Data Form for Williamstown Turloughs SAC (2018a) identifies that the


▪ Sand and gravel quarries

▪ Mechanical removal of peat

▪ Water abstraction from groundwater and other human induced changes in hydraulic

conditions

▪ Increased drainage.

▪ Increased agricultural intensification.

▪ Increased nutrient and fertiliser run-off from surrounding areas.

4.23 Inner Galway Bay SPA (004031)

This SPA is a very large, marine-dominated site with an inner bay, which is protected from exposure to the

Atlantic by the Aran Islands and Black Head, and a number of subsidiary bays and inlets (e.g. Poulnaclough,

Aughinish, Kinvarra). These subsidiary bays add variety to the patterns of water movement and sediment

deposition in the bay and result in a range of marine habitats and communities. The shoreline is equally varied,

with mixtures of bedrock shore, shingle beach, sandy beach and fringing saltmarsh (NPWS, 2014e).

Galway Bay is one of the most important ornithological sites in the western region, supporting an excellent

diversity of wintering wetland birds. It supports internationally important wintering populations of Great Northern

Diver and Brent Goose, and nationally important populations of sixteen other species (Black-throated Diver,

Cormorant, Mute Swan, Wigeon, Teal, Shoveler, Redbreasted Merganser, Ringed Plover, Golden Plover,

Lapwing, Dunlin, Bar-tailed Godwit, Curlew, Redshank, Greenshank and Turnstone). Of particular note are the



populations of Red-breasted Merganser and Ringed Plover represent 6.8% and 2.3% of the respective national

totals. The site is also an important wintering site for gulls (NPWS, 2014e).

The site has several important populations of breeding birds, most notably colonies of Sandwich Tern (81 pairs

in 1995) and Common Tern (99 pairs in 1995). A large Cormorant colony occurs on Deer Island – this had 205

pairs in 1985 and 300 pairs in 1989 (NPWS, 2014e).

Inner Galway Bay also provides good quality habitat for Common Seal. In 1984, this seal colony was one of the

top three sites in the country, with over 140 animals recorded. The seals use a range of haul-out sites distributed

through the bay. The site also provides optimum habitat for Otter (NPWS, 2014e).


Table 4-22 Qualifying Interests of Inner Galway Bay SPA (004031)


A003 Great Northern Diver Gavia immer - Population trend

- Distribution

A017 Cormorant Phalacrocorax carbo - Breeding population abundance: apparently occupied

nests (AONs)

- Productivity rate

- Distribution: breeding colonies

- Prey biomass available


- Disturbance at breeding site

- Population trend

- Distribution

A028 Grey Heron Ardea cinerea - Population trend

- Distribution A046 Brent Goose Branta bernicla hrota

A050 Wigeon Anas penelope

A052 Teal Anas crecca

A056 Shoveler Anas clypeata

A069 Red-breasted Merganser

Mergus serrator

A137 Ringed Plover Charadrius hiaticula

A140 Golden Plover Pluvialis apricaria

A142 Lapwing Vanellus

A149 Dunlin Calidris alpina alpina

A157 Bar-tailed Godwit Limosa lapponica

A160 Curlew Numenius arquata

A162 Redshank Tringa totanus

A169 Turnstone Arenaria interpres

A179 Black-headed Gull

Chroicocephalus ridibundus

A182 Common Gull Larus canus

A191 Sandwich Tern Sterna sandvicensis - Breeding population abundance: apparently occupied

nests (AONs)

- Productivity rate: fledged young per breeding pair




A193 Common Tern Sterna hirundo





A999 Wetlands - Habitat area


The Conservation Objectives for the Inner Galway Bay SPA are to (NPWS, 2013a):

▪ To maintain the favourable conservation condition of the bird species listed in Table 4-22

in Inner Galway Bay SPA.

▪ To maintain the favourable conservation condition of wetland habitat in Inner Galway

Bay SPA as a resource for the regularly occurring migratory waterbirds that utilise it.

Favourable conservation condition is defined by a series of attributes and targets, which are defined on a

habitat/species basis. The attributes for each habitat/species are detailed in Table 4-22 above.


Background data from the Natura 2000 Data Form for Inner Galway Bay SPA (2017t) identifies that the site is

vulnerable to:

▪ Agricultural activities such as fertilisation and grazing

▪ Sewage effluent and detritus pollution form aquaculture industry.

▪ Disturbance to birds from aquaculture activities.

▪ Urban expansion from Galway City.

▪ Reclamation of land from sea, estuary or marsh

▪ Disturbance from recreational activities including fishing and hunting

4.24 Lough Carra SPA (004051)

Lough Carra is a hard water marl lake located within the Corrib catchment. It is a shallow, springfed lake. The

water is alkaline in pH and has a well-known pellucid-green colour from calcareous encrustations. The site is

significant in terms of its ornithology during the winter and summer months as it supports nationally important

populations. Populations of importance include overwintering Shoveler, Mallard and Gadwall. Lough Carra

contains numerous islands and Common Gull are known to utilise these areas for nesting; the site contains over

6% of the national total for Common Gull (NPWS, 2014f).

The site is also of importance for other faunal species including Otter Lutra lutra and White-clawed Crayfish

Austropotamobius pallipes (NPWS, 2014f).


Table 4-23 Qualifying Interests of Lough Carra SPA (004051)


A182 Common Gull Larus canus - Population trend

- Distribution

From: Inner Galway Bay SPA Conservation Objectives (NPWS,

2013v)




The Conservation Objective for Lough Carra SPA is to maintain or restore the favourable conservation condition

of the bird species listed as Special Conservation Interests for this SPA (see Table 4-23) (NPWS, 2018p).



Background data from the Natura 2000 Data Form for Lough Carra SPA (2017u) identifies that the site is

vulnerable to:

▪ Eutrophication of the mesotrophic system.

▪ Increased algal growth.

▪ Leisure fishing

▪ Clearance of lakeshore vegetation.

▪ Intensification of agriculture.

4.25 Lough Corrib SPA (004042)

Lough Corrib is the largest lake in Ireland and can be subdivided into two parts, a shallow basin underlain by

Carboniferous Limestone in the south and a larger, deeper basin underlain by more acidic rocks in the north

(NPWS, 2014g). Section 4.14 describes the habitats present within the corresponding SAC.

Lough Corrib is one of the top five sites in the country for wintering waterfowl, with internationally important

numbers of Pochard. It regularly supports in excess of 20,000 waterfowl, again making it of international

importance (NPWS, 2014g).

It is also nationally the most important site for Pochard, Tufted Duck and Coot, and it supports nationally important

numbers of Mute Swan, Gadwall, Shoveler, Golden Plover and Lapwing. Other notable species present include

Greenland White-fronted Goose, and relatively small numbers of Whooper Swan, Wigeon, Teal, Mallard,

Goldeneye, Curlew and Cormorant (NPWS, 2014g).

Lough Corrib is also a traditional breeding site for gulls and terns with various islands used form nesting each

year. There are nationally important populations of Common Tern and Arctic Tern, and substantial colonies of

Black-headed Gull and Common Gull, with Lesser and Great Blackbacked Gull and Herring Gull also breeding

(NPWS, 2014g).

Whilst only colonised in the 1970/80s by nesting Common Scoter, Lough Corrib now supports approximately

half of the national population of this rare duck, a Red Data Book species. The population has been stable since

the mid-1990s, with 36 pairs recorded in the most recent survey in 1999 (NPWS, 2014g).


Table 4-24 Qualifying Interests of Lough Corrib SPA (004042)


A395 Greenland White-fronted Goose

Anser albifrons flavirostris

- Population trend

- Distribution


2013a)

A051 Gadwall Anas strepera

A056 Shoveler Anas clypeata

A059 Pochard Aythya ferina

A061 Tufted Duck Aythya fuligula

A065 Common Scoter Melanitta nigra

A082 Hen Harrier Circus cyaneus



A125 Coot Fulica atra

A140 Golden Plover Pluvialis apricaria

A179 Black-headed Gull



A193 Common Tern Sterna hirundo - Breeding population abundance: apparently occupied nests

(AONs)






From: Inner Galway Bay SPA Conservation Objectives (NPWS, 2013a)

A194 Arctic Tern Sterna paradisaea



2013a)


The Conservation Objective for Lough Corrib SPA is to maintain or restore the favourable conservation condition

of the bird species listed as Special Conservation Interests for this SPA (see Table 4-24) (NPWS, 2018q).



Background data from the Natura 2000 Data Form for Lough Corrib SPA (2017v) identifies that the site is

vulnerable to:

▪ Agriculture activities such as use of fertiliser or overgrazing

▪ Fishing and hunting activities

▪ Deterioration of water quality of lake.

4.26 Lough Mask SPA (004062)

Lough Mask is the sixth largest lake in Ireland, extending of over 14km along its longest axis. It is underlain by

Carboniferous Limestone and is fed by a number of rivers including the Cloon, Robe and the stream flowing from

Lough Carr in the north-east. The main outflow is from the south and connects to Lough Corrib. The lake varies in

depth, but has moderately hard water. The trophic status of the lake changed during the 1990s from oligotrophic

to mesotrophic due to a steady increase in phytoplankton growth, although vegetation is characteristic of

oligotrophic systems (NPWS, 2014h).

Lough Mask is one of the most important sites in the country for nesting Black-headed Gull, Common Gull and

Lesser Black-backed Gull, along with Common Tern. In the winter a range of waterfowl, especially diving duck

use the lake; the Tufted Duck population being of national importance. In winter it also supports populations of

Whooper Swan, Greenland White-fronted Goose, Wigeon, Teal, Mallard, Pochard, Goldeneye, Coot, Red-

breasted Merganser, Little Grebe, Mute Swan and Cormorant (NPWS, 2014h).




Table 4-25 Qualifying Interests of Lough Mask SPA (004062)


A061 Tufted Duck Aythya fuligula

- Population trend

- Distribution


2013a)

A179 Black-headed Gull Chroicocephalus ridibundus


A183 Lesser Black-backed Gull Larus fuscus

A395 Greenland White-fronted Goose

Anser albifrons flavirostris

A193 Common Tern Sterna hirundo - Breeding population abundance: apparently occupied nests

(AONs)







2013a)



2013a)


The Conservation Objective for Lough Mask SPA is to maintain or restore the favourable conservation condition

of the bird species listed as Special Conservation Interests for this SPA (see Table 4-25) (NPWS, 2018r).



Background data from the Natura 2000 Data Form for Lough Mask SPA (2017w) identifies that the site is

vulnerable to:

▪ Agricultural intensification.

▪ Surrounding commercial/domestic activities causing disturbance.

▪ Rise in Mink predation on breeding Gull colonies.



4.27 Description of the receiving environment - Ecological Walkover Survey Results

4.27.1 Introduction

To further inform the Appropriate Assessment process, the OPW selected a number of channels within the Corrib

Arterial Drainage Scheme for assessment through the undertaking of an ecological walkover survey. The selected

channels are those located in, or within 100m of, a European site. This section summarises the methodology and

findings of these surveys.

All data collected on site has been inputted into a GIS system and provided to OPW to enhance understanding

of the baseline environment and inform future works. See Section 1.4 of this report for Methodology.

This section summarises the findings of the ecological walkover surveys of channels relative to the proposed

maintenance works for the Corrib Arterial Drainage Maintenance Scheme (2020 – 2024).

4.27.2 Habitat Overview

Due to the size of the Corrib catchment scheduled drainage maintanence for the Corrib is split into three sections;

Headford, Clare and Mask. As such, habitat descriptions are described in terms of the Headford, Clare and

Mask sections. Overall fifty-eight Fossitt habitats (Table 4-26) were identified during the ecological walkover

survey, along with five mixed or mosaic habitats of these described. The two most common habitat types present

throughout the catchment were Improved agricultural grassland (GA1) and Wet grassland (GS4).

Table 4-26 Habitats identified within the Corrib catchment

Habitats found along the Corrib Scheme

BC1 (Arable crops) BC2 (Horticultural land)

BL3 (Buildings and artificial surfaces) CW2 (Tidal rivers)

ED2 (spoil and bare ground) ED3 (Recolonising bare ground)

FL1 (Dystrophic lakes) FL2(Acid oligotrophic lakes)

FL6 (Turloughs) FL8 (Other artificial lakes and ponds)

FW2 (Depositing/lowland rivers) FW3 (Canals)

GS1 (Dry calcareous and neutral grassland) GS2 (Dry meadows and grassy verges)

HD1 (Dense bracken) HH1 (Dry siliceous heath)

PB1 (Raised bog) PB3 (Lowland blanket bog)

PF3 (Transitional mire and quaking bog) WD1 (Mixed broadleaved woodland)

WD4 (Conifer plantation) WD5 (Scattered trees and parkland)

WN1 (Oak-birch-holly woodland) WN2 (Oak-ash-hazel woodland)

WN6 (Wet willow-alder-ash woodlands) WN7 (Bog woodland)

WS3 (Ornamental/non-native shrub) GM1 (Marsh)

BC3 (Tilled land) BL2 (Earth banks)

ED4 (quarry) ER2 (exposed calcareous rock)

FL3 (Limestone/marl lake) FL4 (Mesotrophic lakes)

FS1(Reed and large sedge swamp) FS2 (Tall-herb swamps)

FW4 (Drainage ditches) GA1 (improved agricultural grassland

GS3 (Dry-humid acid grassland) GS4 (Wet grassland)

HH2 (Dry calcareous heath) HH3 (Wet heath)

PB4 (Cutover bog) PF1 (Rich fen and flush)

WD2(Mixedbroadleaved/coniferwoodlands) WD3 (Mixed conifer woodland)

WL1 (Hedgerows) WL2 (Treelines)

WN4 (Wet pedunculate oak-ash woodland) WN5 (Riparian Woodland)

WS1 (Scrub) WS2 (Immature woodland)

GA2 (Amenity grassland (improved))



BC1 Arable crop/ BC2 Horticultural land/ BC3 Tilled land

Collectivly this group of cultivated habitats makes up less than 1% of the habitat surveyed in the Corrib catchment.

None of these habitats were recorded in the Mask sub-catchment. These habitats were recorded in localised

areas in or around other agricultureal lands

BL2 Earth banks

Earth banks were only recorded within the Clare sub-catchment during the survey. They were encountered along

tributaries and the main channel of the Clare River.

BL3 (Buildings and artificial surfaces)

This habitat is found throughout the Scheme. Buildings and artificial surfaces include roads, parking areas and

bridges as well as structures such as houses and farm buildings. Large sections of the Corrib in Galway city,

Claregalway and Oughterard were classified as BL3.

CW2 (Tidal rivers)

This habitat type was recorded at one location during the survey which was the lower reaches of the River Corrib

and is tidal in nature.

ED2 (spoil and bare ground)

Recorded in localised areas across the scheme within the Headford and Clare sub-catchments but not recorded

within the Mask sub-catchment.

ED3 (Recolonising bare ground)

Recorded in localised areas across the scheme within the Headford and Clare sub-catchments but not recorded

within the Mask sub-catchment. This habitat includes any areas where bare or disturbed ground, derelict sites or

artificial surfaces of tarmac, concrete or hard core have been invaded by herbaceous plants includuing Colt’s

Foot Tussilago farfara, Nettle Urtica dioica, Dandelion Taraxacum spp., willow-herbs Epilobium spp. and

ragworts Senecio spp.

ED4 (quarry)

Two quarries were identified in the Clare sub-catchment as part of the walkover surveys. One is situated near

Ross Lake on the west side of the Corrib while the second is located outside of Lackagh on the East side of the

Corrib.

ER2 (exposed calcareous rock)

Exposed calcareous rock habitat was recorded in the Mask and Clare sub-catchments and was absent from the

Headford sub-catchment within the Corrib scheme. This habitat occurs in upland and lowland areas and can

include inland cliffs and crags, limestone pavement, and rock surfaces that are exposed by excavation.

FL1 (Dystrophic lakes)

Three dystrophic lakes were identified in the Clare sub-catchment. All are located within an area of bog land in

the townland of Knocknagroagh.

FL2(Acid oligotrophic lakes)

A total of nine records of acid oligotrophic lakes within the Corrib catchment. Therer were no records for this

habitat type in the Mask sub-catchment. All records are for Lough Corrib. An aquatic survey did not take place

as this was outside the scope of the survey, however, observations were made from the banks of the lake and

this definition was determined as follows. Lough Corrib was defined under the Lough Corrib Site Synopsis as hard

water lake habitat (3140) within the southern basin where these show records of acid oligotrophic lakes are

recorded.



FL3 (Limestone/marl lake)

A number of limestone/marl lakes were recorded throughout the three sub-catchments of the Corrib catchment.

The highest concentration of records are within the Mask sub-catchment.

FL4 (Mesotrophic lakes)

There is one record of mesotrophic lakes within the Corrib catchment. It is situated in the Clare sub-catchment

(Lough Dolloug).

FL6 (Turloughs)

A total of 33 turlough habitats were recorded throughout the the three sub-catchments of the Corrib catchment.

FL8 (Other artificial lakes and ponds)

A number of fenced attenuation ponds were recorded in the Clare sub-catchment along the M17 road.

FS1(Reed and large sedge swamp)

This is a common habitat throughout all thee sub-catchments and is often associated with wet grassland, upper

salt marsh or improved agricultural grassland. This habitat is dominated by one or a small number of species

where stands of vegetation can range from very dense to open. Most of this habitat is found throughout the Feale

river in small patches or sections on the banks of the river, or as an island/ bar in the river

FS2 (Tall-herb swamps)

This habitat is common along the rivers and lakes throughout all three sub-catchments. It is identified by stands

of herbaceous vegetation that occur in wet areas where the water table is above the ground surface for most of

the year. This habitat contains Iris sp., Bulrush Typha latifolia, Branched bur-reed Sparganium erectum, Lesser

spearwort Ranunculus flammula, watercress Nasturtium officinale, Marsh bedstraw Galium palustre, Fools

watercress Apium nodiflorum, Water pepper Persicaria hydropiper, Brooklime Veronica beccabunga, Marsh

willowherb Epilobium palustre & Purple loosestrife Lythrum salicaria and Juncus spp

FW2 (Depositing/lowland rivers)

The Clare river and the upper reaches of the Corrib River are clasified as depositing/lowland rivers. Bank

vegetation reflected adjacent habitats and varied between reedbeds, wet grassland, buildings and artificial

surfaces and improved agricultural grassland. Floating river vegetation was visible in several locations and

included Broadleaved Pondweed Potamogeton natans and Duckweed Lemna spp.

FW3 (Canals)

The only record of canal habitat is within the Corrib catchment in Galway city.

FW4 (Drainage ditches)

Several drainage ditches were recorded and surveyed in the study area. The flora supported by these drainage

ditches varied depended on the degree of water contained therein. They were occasionally overgrown with

hedgerows and treelines.

GA1 (improved agricultural grassland)

Improved agricultural grassland is the main habitat present within the Corrib catchment accounting for 32% of

all habitats recorded across the three sub-basins. Typical vegetation included Perennial Rye-grass Lolium

perenne, dock Rumex spp., plantain Plantago spp. and clover Trifolium spp. Wetter fields included Rye-grass,

Timothy Phleum pratense, Yorkshire Fog Holcus lanatus, Creeping Buttercup Ranunculus repens, thistle Cirsium spp.

and rushes Juncus spp.



GA2 (Amenity grassland (improved))

This habitat was recorded mainly within or in the immediate surrounding area of residential properties, as golf

courses and sports pitches. This type of grassland is improved, or species-poor, and is managed for purposes

other than for farmland. They are regularly re-seeded, mown and fertilisers and herbicides are often applied.

The vegetation is made up of various grasses, and broadleaved herbs such as Daisy Bellis perennis, Dandelion

Taraxacum spp., clovers and plantains Plantago spp. are common.

GM1 (Marsh)

Marsh habitat occurs within the survey area in a small number of locations and is noted for containing stands of

Yellow Iris. Marsh habitat was recorded in both the Clare and Headford sub-catchments but was absent from

the Mask sub-catchment. Marsh occurs on level ground near river banks and lakeshores where the water table is

close to ground level for most of the year. It supports a high proportion of wetland species in addition to the

typical dominants of rushes Juncus spp. and sedges Carex spp. but the proportion should not exceed 50% over

herbs. Broadleaved herbs may include Meadowsweet Filipendula ulmaria, Water Mint Mentha aquatica, Marsh

Thistle Cirsium palustre, Wild Angelica Angelica sylvestris, Marsh Pennywort Hydrocotyle vulgaris, Common

Valerian Valeriana officinalis, Purple loosestrife Lythrum salicaria, Marsh Woundwort Stachys palustris and

Marsh Cinquefoil Potentilla palustris.

GS1 (Dry calcareous and neutral grassland)

Dry calcareous and neutral grassland habitat was relatively common across all sub-catchments with this habitat

making up approximately 9.5% of all habitats recorded across the Corrib catchment. Characteristic species are

Oxeye Daisy Leucanthemum vulgare, Wild Angelica, Common Knapweed Centaurea nigra, False Oat-grass,

Cock's Foot and Willowherbs. Some Bramble, Gorse, Ash, Alder and Hawthorn are also present. This habitat has

the potential to be semi-natural dry grasslands and scrubland facies on calcareous substrates (Festuco-Brometea)

(*important orchid sites) (6210).

GS2 (Dry meadows and grassy verges)

Dry meadows and grassy verge habitat occur within the survey area in a small number of locations and is absent

from the Headford sub-catchment. Grassy verges are occasionally mown and rarely treated with herbicides, and

there is little or no grazing or fertiliser application. Species detected were Yorkshire fog Holcus lanatus, Fescue

Festuca sp., Perrenial Rye-grass Lolium perenne, Sand couch Elymus juncea, Nettles Urtica spp., Thistle Cirsium

sp., Meadowsweet Filipendula ulmaria, Rumex sp., Cleavers Galium aparine, Willowherb Epilobium sp., Purple

loosestrife Lythrum salicaria, and Bindweed Calystegia sepium. This habitat has links with the Annex 1 habitat

'Lowland hay meadows (Alopecurus pratensis, Sanguisorba officinalis) (6510)'.

GS3 (Dry-humid acid grassland)

This habitat type has only been identified within the Clare sub-catchment at a small number of locations. Dry-

humid acid grassland is described as unimproved or semi-improved grassland that occurs on free-draining acid

soils that may be dry or humid, but not waterlogged. It is characterised by dense low swards of narrow-leaved

grasses such as bents (Agrostis capillaris, A. tenuis), fescues (Festuca spp.) and may include Sweet Vernal-grass

Anthoxanthum odoratum, Wavy Hair-grass Deschampsia flexuosa, Mat-grass Nardus stricta and Purple Moor-

grass Molinia caerulea. Wood-rushes Luzula spp., Heath Rush Juncus squarrosus and small sedges may also be

prominent. Common broadleaved herbs include Heath Bedstraw Galium saxatile, Tormentil Potentilla erecta,

White Clover, Devil’s-bit Scabious Succisa pratensis, Sheep’s Sorrel Rumex acetosella, and Yarrow Achillea

millefolium

GS4 (Wet grassland)

Wet grassland habitat was frequently recorded across all three sub-catchments of the Corrib scheme and make

up 19.8% of the total habitat records. Areas of wet grassland were found along the river banks and adjacent



to paths and drainage ditches. Many of these wet grasslands were reported to have transitioned originally from

improved agricultural grassland. This type of grassland occurs on wet or waterlogged, poorly-drained soils and

may be subjected to seasonal or periodic flooding. Wet grassland are dominated by rushes Juncus spp. and

sedges Carex spp., and some grass species such as Yorkshire-fog Holcus lanatus, Creeping Bent Agrostis

stolonifera, Marsh Foxtail Alopecurus geniculatus, Rough Meadow-grass Poa trivialis and Tufted Hair-grass

Deschampsia caespitosa are present, with a high proportion of broadleaved herbs including Creeping Buttercup

Ranunculus repens, Marsh Thistle, Silverweed Potentilla anserina, Meadowsweet

HD1 (Dense bracken)

Dense bracken habitat was recorded in the Clare and Headford sub-catchments and were typically seen

recolonising past bare ground areas or as fringe habitats. The habitat is classified as dominated by Bracken

Pteridium aquilinum, where cover exceeds 50% overall.

HH1 (Dry siliceous heath)

Dry siliceous heath habitat was only recorded at two locations within the Clare sub-catchment. Typical species

include Ling (Callua vulgaris), Bell Heather (Erica cinereal), Bilberry (Vaccinium myrthillus) and low-grwing

Western Gorse (Ulex gallii).

HH2 (Dry calcareous heath)

Dry calcareous heath was not recorded in the Clare sub-catchment and was occasionally recorded across the

other two sub-catchments. Dry calcareous heath occurs mainly in limestone areas on rocky ground or shallow soils.

Dry calcareous heath usually comprises some Ling (Calluna vulgaris), Purple Moorgrass (Molinia caerulea) and

Tormentil (Potentilla erecta).

HH3 (Wet heath)

Wet heath habitat was not recorded in the Mask sub-catchment. It was frequent in the Clare and Headford sub-

catchments. Wet heath was most commonly recorded along the edge of bog habitats located adjacent to the

surveyed river channels. Species recorded for this habitat include: Molinia sp.; Wild angelica; Ling (Calluna

vulgaris); Marsh woundwort; Marsh cinquefoil; Soft rush; Meadowsweet; Devil's bit scabious (Succisa pratensis);

Great tussock sedge (Carex paniculata); and Cottongrass (Eriophorum angustifolium).

PB1 (Raised bog)

Raised bog habitat was recorded throughout all three sub-catchments of the Corrib scheme. Raised bog is present

in Lough Corrib SAC and has a potential to be the Annex I habitats '*Depressions on peat substrates of the

Rhynchosporion (7150)', 'Active raised bogs [7110]' and 'Degraded raised bogs still capable of natural

regeneration [7120]'. Raised bogs are accumulations of deEPacid peat (3-12 m) that originated in shallow lake

basins or topographic depressions. Sphagnum mosses dominate the ground layer that supports specialised plant

communities that are low in overall diversity.

PB3 (Lowland blanket bog)

Lowland blanket bog habitat was recorded three times within the Clare sub-catchment only and was restricted

to an area adjacent to the upper reaches of the Dalgan River.

PB4 (Cutover bog)

Areas of recently cutover bog were recorded in the Clare and Headford sub-catchments. There are no records

of this habitat in the Mask sub-catchment. Cutover bog was recorded adjacent to river channels in a number of

locations. Heather species and Bog Asphodel Narthecium ossifragum were recorded.



PF1 (Rich fen and flush)

Rich fen and flush habitat was recorded in all three sub-catchments of the Corrib scheme. Rich fen and flushes

are fed by groundwater or flowing surface waters that are at least mildly base-rich or calcareous and are

usually found over areas of limestone bedrock. Vegetation is typically dominated by Black Bog-rush (Schoenus

nigricans) and/or small to medium sedges such as Carex viridula, C. nigra, C. dioica and C. panicea. Other

prominent components of the vegetation include rushes, particularly Blunt-flowered Rush (Juncus subnodulosus),

Purple Moor-grass (Molinia caerulea) and Marsh Pennywort (Hydrocotyle vulgaris). This habitat has links with the

Annex 1 habitat 'Alkaline fens (7230)' and ‘*calcareous fens with Cladium mariscus and species of the Caricion

davallianae (7210)’.

PF3 (Transitional mire and quaking bog)

Transitional mire and quaking bog habitats were only recorded at two locations within the Mask sub-catchment

of the Corrib scheme along the shoreline of Cloon Lough. This habitat was absent from both the Clare and

Headford sub-catchments. Transition mires and quaking bogs are extremely wet peat-forming systems with

characteristics that are intermediate between poor and rich fens.

WD1 (Mixed broadleaved woodland)

Mixed broadleaved woodland habitats were present across all three sub-catchments of the Corrib scheme. The

majority or records were recorded in the Clare sub-catchment. This category generally includes planted

woodland areas with 75-100% cover of broadleaved trees, and 0-25% cover of conifers. Species recorded

includes; Sycamore, holly, birch and ash.

WD2 (Mixed broadleaved/conifer woodlands)

Mixed broadleaved/conifer woodland habitats were present across all three sub-catchments of the Corrib

scheme though this habitat was not as frequently as other woodland habitat types across the scheme. This general

category includes woodland areas with mixed stands of broadleaved trees and conifers, where both types have

a minimum cover of 25%, and a maximum of 75%. Trees may be either native or non-native species. Species

composition was varied in each habitat location.

WD3 (Mixed conifer woodland)

Mixed conifer woodland habitats were recorded in the Mask and Headford sub-catchments but was absent from

the Clare sub-catchment. This general category includes woodland areas with 75-100% cover of conifers, other

than conifer plantation. Species composition consisting of Spruce Picea spp. and Pine.

WD4 (Conifer plantation)

Conifer plantations were present across the Corrib scheme in all sub-catchments. This category is used for areas

that support dense stands of planted conifers where the broadleaved component is less than 25% and the

overriding interest is commercial timber production. Conifer plantations are often surrounded by a narrow

boundary of mixed broadleaved woodland. This habitat was recorded at various life stages throughout the

catchment.

WD5 (Scattered trees and parkland)

Areas of scattered trees and parkland were rarely observed during the surveys and were entirely absent from

the Mask sub-catchment. The grassland aspect of this habitat was usually comprised of improved grassland

species, such as Perennial ryegrasses, while the tree species were most frequently either Hawthorn, Ash, Elder or

Willow spp.



WL1 (Hedgerows)

Hedgerows are found throughout the survey area, occurring in this area tend to be along embankments, drainage

ditches and bordering agricultural grassland. Hedgerow habitat mostly composed of Hawthorn Crataegus

monogyna, Blackthorn Prunus spinosa, Gorse Ulex europaeus, Holly Ilex aquifolium, Dog-rose Rosa canina or

Bramble Rubus fruticosus agg. in addition to many other native and non-native trees and shrubs including Ash,

Hazel Corylus avellana, Beech Fagus sylvatica, Elder Sambucus nigra, elms Ulmus spp. and willows Salix spp.

WL2 (Treelines)

Treeline habitat was recorded across all three sub-catchments of the Corrib scheme. Often occurring along river

banks and as a boundary to fields or drainage ditches, and also along embankments. Treelines are found parallel

to the river in many locations, and composed of many species including Ash Fraxinus excelsior, Sycamore Acer

pseudoplatanus, Alder Alnus glutinosa, and Willow Salix spp., and occasionally a treeline composed of Sitka

Spruce Picea sitchensis.

WN1 (Oak-birch-holly woodland)

Oak-birch-holly woodland habitats were only recorded at four locations within the Clare sub-catchment and

were not recorded within either the Mask or Headford subcatchments. All records of this habitat are adjacent to

the River Corrib. This habitat is considered potential Annex 1 habitat Old sessile Oak woods with Ilex and

Blechnum in the British Isles (91AO).

WN2 (Oak-ash-hazel woodland)

Oak-ash-hazel woodland habitats are found across the Corrib scheme scattered across all three sub-catchments.

This habitat is described as a semi-natural woodland that occurs on base-rich or calcareous soils that are

generally dry or well-drained or on rocky limestone terrain. Woodland is dominated by Pedunculate Oak, Ash

or Hazel or by various mixtures of these species.

WN4 (Wet pedunculate oak-ash woodland)

Wet pedunculate oak-ash woodland habitat was recorded across the scheme in all three sub-catchments at a

low frequency. This woodland habitat is associated with areas that are flooded or waterlogged in winter, but

which dry out in summer and are dominated by Pedunculate Oak Quercus robur and/or Ash with Hazel,

Hawthorn, Holly and willows. It has potential to be priority habitat, ‘*alluvial forests with Alnus glutinosa and

Fraxinus excelsior (Alnopadion, Alnion incanae, Salicion albae) (91E0).

WN5 (Riparian Woodland)

Riparian woodland was recorded across all three sub-catchments of the Corrib scheme with the majority of

records being within the Headford sub-catchment. Riparian woodlands are subject to frequent flooding, or the

water levels may fluctuate as a result of tidal movement (in the lower reaches of the river). Riparian woodland

is dominated by stands of willows with a field layer characterised by broadleaved herbs such as Nettle Urtica

dioica, Creeping Buttercup, Wood Dock Rumex sanguineus, Meadowsweet, Wild Angelica, Hemlock

Waterdropwort, and Hedge Bindweed Calystegia sepium. All three locations have potential to be a priority

Annex 1 habitat *Alluvial forests with Alnus glutinosa and Fraxinus excelsior (Alno-padion, Alnion incanae,

woodland Salicion albae) (91E0). Species recorded were Willow, Alder, Ash, Holly and Hazel.

WN6 (Wet willow-alder-ash woodlands)

Wet willow-alder-ash woodland habitats were frequently recorded across the Corrib scheme. This broad

category includes woodlands of permanently waterlogged sites that are dominated by willows Salix spp., Alder

Alnus glutinosa or Ash Fraxinus excelsior, or by various combinations of some or all of these trees. Species

recorded were Beech Fagus sylvatica, Ash Fraxinus excelsior, Alder Alnus glutinosa, Sycamore Acer



pseudoplatanus, Holly Ilex aquifolium, Bramble Rubus fruticosus agg., Willow Salix sp., Sea aster Aster tripolium,

and Common cordgrass Spartina anglica.

WN7 (Bog woodland)

Bog woodland habitat was recorded at one location in the Corrib scheme within the Clare sub-catchment. This

habitat was recorded within the Lough Lurgeen Bog/Glenamaddy Turlough SAC This habitat includes woodlands

of intact ombrotrophic bogs, bog margins and cutover bog and is commonly associated with former turf cutting

activity or drainage. It may also occur in areas of cutover bog where most of the peat has been removed. Downy

Birch Betula pubescens is the usual dominant and may form pure stands. This habitat is not recognised as a priority

habitat in this SAC.

WS1 (Scrub)

This is a common habitat recorded across all three sub-catchments with records accounting for 6% of the total

habitats recorded across the Corrib scheme. This habitat is often recorded on the embankments and its

composition is variable. Scrub vegetation included Gorse, Nettle, Brambles and thistles, rendering the area

impassable for surveying.

WS2 (Immature woodland)

Immature woodland habitat was recorded infrequently across all three sub-catchments of the Corrib scheme. This

habitat is described as areas that are dominated by young or sapling trees that have not yet reached the

threshold heights. Species recorded consisted of Alder, Hazel and Conifers.

WS3 (Ornamental/non-native shrub)

Ornamental/non-native shrub habitat was recorded in the Clare and Headford sub-catchments and was absent

from the Mask sub-catchment during this survey. Habitat is typically described as dominated by ornamental and

non-native shrubs which originate from planting and can be found in formal beds and borders in gardens, parks

and other landscaped areas. The range of possible non-native shrubs is extensive but some of the more common

examples include Fuchsia (Fuchsia magellanica), Butterfly-bush (Buddleja davidii), Box (Buxus sempervirens),

Snowberry (Symphoricarpos albus), Cotoneaster (Cotoneaster spp.), Rhododendron (Rhododendron ponticum)

and Cherry Laurel (Prunus laurocerasus).

A sample of the habitat data collected during the field survey work is provided in Figure 4-1.



Figure 4-1: Sample Habitat Map

Annex I Habitat Mapping and Floating River Vegetation

As part of the habitat mapping process, those habitats considered to represent habitat types listed on Annex I

of the Habitats Directive were also noted (see Appendix B). Information on those habitat areas that have been

identified as representing Annex I habitats is detailed within the provided GIS shapefiles and on maps given in

Appendix B, however, a summary of the Annex I habitats found and their location is detailed below.

Table 4-27 Annex I Habitats within Corrib Arterial Drainage Scheme

Annex I Habitat

Type

Description (From: NPWS, 2019) Equivalent

Fossitt Habitats

Location Found

in Corrib

Scheme

Oligotrophic

waters containing

very few minerals

of sand plains

(Littorelletalia

uniflorae) (3110)

Waterbodies of this type occur in areas of soft water, are

nutrient poor and are frequently associated with acid bedrock

(i.e. granite and old red sandstone) overlain by peat. It is best

developed on more gently sloping lake beds over variable

substrata and along sheltered shorelines.

It is dominated by a group of species, including Quillworts

Isoetes spp., Shoreweed Littorella uniflora, Water Lobelia

Lobelia dortmanna and Pipework Eriocaulon aquaticum. Bulbous

Rush Juncus bulbosus, Alternate Water-milfoil Myriophyllum

alterniflorum, Bog Pondweed Potamogeton polygonifolius and

Floating Bur-reed Sparganium angustifolium also frequently

occur. Ireland is a stronghold for the habitat, given the large

number of lakes in which it occurs and its widespread distribution.

FL2 Acid

oligotrophic

lakes

At the

downstream end

of a number of

scheme channels

that discharge

into the northern

basin of Lough

Corrib



Annex I Habitat

Type


Fossitt Habitats

Location Found

in Corrib

Scheme

Hard

oligomesotrophic

waters with

benthic vegetation

of Chara spp.

(3140)

Groundwater dominated waterbodies with a high base

content, usually confined to limestone areas or places with

other base-rich substrates (e.g. magnesium). Characterised by

very clear water and low nutrient status, and are usually

restricted to locations where the supplying catchment or

aquifer is unaffected by intensive land-use or other sources

of nutrients.

Abundant charophytes (stoneworts), which can form dense beds

over a significant portion of the lake bottom, are typically the

most prominent component of the vegetation. Charophyte

diversity is often high in Irish lakes of this type, and a number

of rare and threatened species can be present. Notable

cyanobacterial crusts can also often be found on bedrock,

stones and cobbles.

FL3

Limestone/marl

lakes

At the

downstream end

of a number of

scheme channels

discharge into

the southern

basin of Lough

Corrib and

Ross Lake

Turloughs (3180)

A depression in a karstic limestone are that is temporarily

and/or seasonally flooded from groundwater. Most are

usually flood in autumn and winter, then drain between April

and July leaving a dry floor (sometimes with residual pools),

although there is considerable variation between turloughs.

They have no natural surface outlet.

Vegetation in turloughs usually has a distinct zonation

determined by water depth, and frequency and duration of

inundation, but do not generally contain unique vegetation

types. Some turloughs are important feedinggrounds for

wintering waterfowl.

FL6 Turloughs

Located

throughout the

northern portion

of the Corrib

Arterial

Drainage

Scheme

(i.e.

Glennamaddy,

Levally,

Pollelamgur,

Caheravoostia,

Thomastown,

Coollisduff,

Shrule).

Hydrophilous tall

herb fringe

communities of

plains and of the

montane to alpine

levels

(6430)

In Ireland there are 3 distinct communities that can be

considered as this habitat type:

1. In lowland areas it occurs as a community of

watercourses, particularly along the unmanaged edges of

slow-moving rivers and on the margins of lakes. Here it is

dominated by tall wetland herbs such as Angelica Angelica

sylvestris, Meadowsweet Filipendula ulmaria, Yellow Iris Iris

pseudacorus, Purple Loosestrife Lythrum salicaria, Common

Valerian Valeriana officinalis and Horsetails Equisetum

fluviatile and E. palustre.

2. In upland areas it occurs as a community of ungrazed

or lightly grazed cliff edges, on calcareous cliffs or wet

siliceous screes with some base-enrichment of the water. These

patches are typically small, with species such as Lady's Mantle

Alchemilla spp., Angelica, Meadowsweet, Marsh Hawksbeard

Crepis paludosa, Water Avens Geum rivale and Lesser

Meadow-rue Thalictrum minus.

FS2 Tall-herb

swamps; GM1

Marsh

Occasionally

present along

the margins of

the River Clare

and some of the

large tributaries

within the

scheme area

(type 1)



Annex I Habitat

Type


Fossitt Habitats

Location Found

in Corrib

Scheme

In the lowlands this habitat may also occur as a nitrophilous

tall herb community of woodland borders. Typical species

may include Garlic Mustard Alliaria petiolata, Cow Parsley

Anthriscus sylvestris, Hemp Agrimony Eupatorium cannabinum,

Herb Robert Geranium robertianum, Wood Avens Geum

urbanum and Butterbur Petasites hybridus.

Semi-natural dry

grasslands and

scrubland facies

on calcareous

substrates

(FestucoBrometea)

(*important orchid

sites)

(6210)

This habitat comprises species-rich communities found on

shallow, well-drained calcareous substrates. It is only

considered as a priority habitat if it is an important orchid site.

Most of these habitats are maintained by grazing.

It includes a mixture of grasses and herbs, with calcicole

species typically frequent. It is often associated with obvious

geological features such as eskers, outcropping limestone rocks

and limestone pavement.

GS1 Dry

calcareous and

neutral

grassland

Small localised

patches

throughout the

Corrib Arterial

Drainage

scheme. Also, on

a small number

of spoil heaps

Molinia meadows

on calcareous,

peaty or

clayeysilt-laden

soils (Molinion

caeruleae)

(6410)

This habitat type in Ireland is represented by both fen and

grassland communities on nutrient poor soils, often with

fluctuating water tables. It is either managed as traditional

hay meadows (i.e. cut only once a year in later

summer/autumn with the hay crop removed) or more usually

by extensive pasture. In Ireland they occur in lowland plains

on neutral to calcareous gleys, or on peaty soils in both the

uplands or lowlands. They generally have a north-western

distribution.

It often occurs as a component of wet pastures or fens, and

frequently in mosaics with dry grassland, heath, mire or scrub

communities.

Purple Moor-grass Molinia caerulea occurs with a wide range

of associated species, including rushes, sedges and tall

growing herbs Meadow Thistle Cirsium dissectum is one of the

key indicator species for this habitat.

GS4 Wet

grassland

Present in a

number of

locations

throughout the

Corrib Arterial

Drainage

scheme

Northern Atlantic

wet heaths with

Erica tetralix

(4010)

This is highly variable habitat in the Irish context, that is an

intermediate, in many regards, between dry heath and

blanket bog. It generally occurs on gently sloping, poorly-

draining ground on shallow or intermediate peat depths

(typically less than 50cm).

It is dominated by a mixture of Purple Moor-grass Molinia

caerulea, Cross-leaved Heath Erica tetralix, Deer-grass

Trichophorum germanicum or Heather Calluna vulgaris,

although not all may be present.

HH3 Wet

heath

Present within

Connemara Bog

Complex SAC

Active raised bogs

(7110)

Active raised bogs are peat-forming ecosystems that have

developed during thousands of years of peat accumulation,

to such an extent that the depth of peat isolates them from

the influence of groundwater. Typically, lowland raised bogs

form a raised dome of peat irrigated solely by rainfall. Such

PB1 Raised

bog

Present in a

number

of locations,

including near

Glennamaddy



Annex I Habitat

Type


Fossitt Habitats

Location Found

in Corrib

Scheme

rainwater-fed ecosystems are very acid and poor in plant

nutrients and typically support a restricted range of species.

A bog is considered ‘active’ if it supports a significant area

of vegetation that is normally peat-forming. Such vegetation

includes plants such as the bog-mosses Sphagnum spp.,

Cotton-grasses Eriophorum spp., Heather Calluna vulgaris and

other ericaceous plants, and the carnivorous sundews Drosera

spp. Active bog vegetation is characteristic of intact (primary)

bog surfaces, but peat-forming communities also occur

frequently on bogs which have previously been cut for peat

(secondary surfaces) but have since become revegetated.

and Kylemore

and in

Monivea Bog

and

Killaclogher Bog

Degraded raised

bogs still capable

of natural

regeneration

(7120)

Degraded raised bogs occur where there has been

widespread disruption, usually by man, to the structure and

function of the peat body. This can involve changes to the

hydrology, vegetation, and physical structure of the bog,

leading to desiccation, oxidation and loss of species or

changes in the balance of the species composition.

In contrast to Active raised bogs, peat is not currently forming

in degraded bog. The vegetation of degraded bog contains

several, but not all, of the species typical of Active raised

bogs, but the relative abundance and distribution of

individual species differs. Degraded raised bogs only

includes examples which are ‘capable of natural

regeneration’ (i.e. where the hydrology can be repaired and

where, with appropriate rehabilitation management, there is

a reasonable expectation of reestablishing vegetation with

peat-forming capability within 30 years).

PB4 Cutover

bog; WD4

Conifer

plantation;

GS4 Wet

Grassland

Present in a

small number of

locations,

including near

Glennamaddy

and

Kylemore and in

Monivea Bog

and

Killaclogher Bog

Calcareous fens

with Cladium

mariscus and

species of the

Caricion

davallianae

(7210)

This habitat type occurs where Great Fen-sedge Cladium

mariscus stands are in contact with Caricium davallianae or

other Phragmition species. It often occurs in Ireland where

monodominant or species-poor stands of Great Fen-sedge

merge with Schoenetum nigricantis. It can also occur in

transitional areas between Great Fen-sedge and other

species-rich alkaline fen vegetation.

It is thought to typically occur in lowland topogenous basins

associated with limestone groundwater with a karstic or

poorly productive flow regime. It can also occur in other

calcareous wetland types such as upland and lowland base-

rich flushes, along the fringes or calcareous lakes and within

turloughs.

PF1 Rich fen

and flush

Present in a

small number of

locations around

the margins of

Lough Corrib,

including at

Keelkill,

Gortmore and

Gortachalla,

and at Ross

Lake.

Alkaline fens

(7230)

Typically, base-rich basin or flush fen systems with extensive

areas of species-rich small sedge communities. They are often

a complex mosaic of habitats, with tall sedge beds,

reedbeds, wet grassland, springs and open-water often co-

occurring at a given site. They can occur beyond peat-

forming systems, for example in dune slacks and wet

grasslands.

PF1 Rich fen

and flush

Present in a

small number of

locations around

the margins of

Lough Corrib,

including

Keelkill, at Ross



Annex I Habitat

Type


Fossitt Habitats

Location Found

in Corrib

Scheme

Lake and within

some turloughs,

including that at

Coollisduff

Bog woodland

(91D0)

Under certain combinations of physical circumstances,

scattered trees can occur across the surface of a bog in a

relatively stable ecological relationship as open woodland,

without the loss of bog species. This true Bog woodland is a

much rarer condition than the progressive invasion of bogs by

trees, through natural colonisation or afforestation following

changes in the drainage pattern which leads eventually to the

loss of the bog community

WN7 Bog

woodland

Present at

Glennamaddy

Estuaries (1130)

Estuaries are defined as the downstream part of a river

valley, subject to the tide and extending from the limit of

brackish water. There is a gradient of salinity from

freshwater in the river to increasingly marine conditions

towards the open sea. The input of sediment from the river,

the shelter of the estuary from wave action, and the often low

current flows typically lead to the presence of extensive

intertidal sediment flats and sediment-filled subtidal channels.

There is usually only a limited extent of rocky habitat.

CW2 Tidal

rivers

The very

downstream

reaches of the

River

Corrib

Floating River Vegetation

The Annex I habitat of watercourses of plain to montane levels with the Ranunculion fluitantis and Callitricho-

Batrachion vegetation [3260] under the Habitats Directive is very broad, especially when the presence of aquatic

mosses is considered; using this broad definition the 'Floating River Vegetation' habitat type will be found in most

watercourses in Ireland (NPWS, 2014h). They are typically watercourses characterised by the abundance of

water-crowfoots Ranunculus spp., subgenus Batrachium (i.e. Ranunculus fluitans, R. penicillatus ssp. penicillatus, R.

penicillatus ssp. pseudofluitans, and R. peltatus and its hybrids), which form floating mats. However, there is no

satisfactory definition of this habitat type and its sub-types and its distribution in Ireland. It can occur over a wide

range of physical conditions from acid, oligotrophic, flashy upland streams dominated by bryophytes to more

eutrophic, slow flowing streams dominated by Ranunculus and water-starwort Callitriche species. The Ranunculus

species can be associated with a wide assemblage of other aquatic plants, such as Water-cress Rorippa

nasturtium-aquaticum, waterstarworts Callitriche spp., water-parsnips Sium latifolium and Berula erecta, water-

milfoils Myriophyllum spp. and Water Forget-me-not Myosotis scorpioides. In some rivers, the cover of these

species may exceed that of Ranunculus species (NPWS, 2014h). Other associated species with this habitat type

can include Horned Pondweed Zannichellia palustris, pondweed species Potamogeton spp. and the moss Fontinalis

antipyretica. Opposite-leaved Pondweed Groelandia densa may also be present, with Flowering Rush Butomus

umbellatus potentially present as part of the bank flora (OPW, 2007).

Floating river vegetation was recorded along several stretches of scheme watercourses during the ecological

surveys, including lengths of the River Clare and a number of tributaries including the Abbert River, Grange River,

Sinking River and Killaclogher River. The areas where this habitat type was recorded are detailed in the GIS

database, along with the species present and an assessment of their abundance.



Lengths of watercourse that, whilst not directly matching the description of Floating River Vegetation above, are

considered to represent good quality riverine habitat are also detailed in the GIS database. Although these

lengths do not contain the characteristic species of the Annex I habitat of 'Floating River Vegetation', the floristic

composition is diverse and consideration should therefore be given to applying the same measures as applied

to stretches of the Annex I habitat in order to protect these species-rich lengths of channel.

Non-native Invasive Species

A number of non-native invasive species were recorded during the survey, including:

▪ Japanese Knotweed Fallopia japonica - Occasional records from the west of the scheme area, in

particular in the Cornamona River area where infestations are noted as being particularly bad.

Also recorded along the full length and both banks of the surveyed section of Maam Flood Relief

channel;

▪ Rhododendron Rhododendron ponticum - Occasional records from the west of the scheme area.

Protected Flora and Fauna

A number of protected fauna species were recorded during the survey including:

▪ Badger Meles meles - evidence of Badger, mainly in the form of latrines, prints and hairs found

on fences, was found scattered throughout the scheme area.

▪ Common Frog Rana temporaria

▪ Otter Lutra lutra - extensive evidence recorded throughout the scheme area, on the River Clare

and a large number of tributaries. A number of holts were also recorded.

▪ Evidence of Fox Vulpes vulpes was also noted in some locations.

▪ A number of structures and trees with the potential to support roosting bats was also recorded.

No species recorded on the Flora (Protection) Order, 1999 were recorded during the survey.

Bird Activity

The bird species recorded during the ecological surveys conducted in the Corrib Arterial Drainage Scheme are

detailed below. Bird records are presented for the Corrib Clare, Corrib Headford and Corrib Mask separately.

Table 4-28 Bird Species Recorded in Corrib Clare Arterial Drainage Scheme

Common Name Latin Name Comment on Location Recorded

Blackbird Turdus merula Frequently recorded throughout surveyed reaches.

Blackcap Sylvia atricapilla On the River Clare

Black-headed Gull Chroicocephalus ridibundus Around the eastern and western shores of Lough

Corrib

Blue Tit Cyanistes caeruleus Frequently recorded throughout surveyed reaches.

Bullfinch Pyrrhula pyrrhula Grange, Dalgin and Abbert Rivers

Chaffinch Fringilla coelebs Frequently recorded throughout surveyed reaches

Chiffchaff Phylloscopus collybita Killaclogher and Grange Rivers and around the

eastern shores of Lough Corrib

Coal Tit Periparus ater On the River Clare

Collared Dove Streptopelia decaocto Grange River

Common Sandpiper Actitis hypoleucos Yellow River and Grange River areas

Common Whitethroat Sylvia communis Dalgin River and on the River Clare

Coot Fulica atra Around the eastern and western shores of Lough

Corrib

Cormorant Phalacrocorax carbo River Corrib and on the River Clare




Crow Corvus corone Frequently recorded throughout surveyed reaches.

Dunnock Prunella modularis Regularly recorded throughout surveyed reaches

Goldfinch Carduelis carduelis Recorded around Glennamaddy Turlough, Ross Lake

and the western shores of Lough Corrib

Greenfinch Chloris chloris Around small watercourses on the western shores of

Lough Corrib

Grasshopper Warbler Locustella naevia On the River Clare and the Dalgin River

Great Tit Parus major Around the western shores of Lough Corrib, on the

River Clare and on Grange River

Greylag Goose Anser anser On the River Clare and around the smaller

watercourses along the eastern shores of Lough Corrib

Grey Heron Ardea cinerea Recorded at a number of locations along the River

Clare

Grey Wagtail Motacilla cinerea Occasional records from the River Clare and its

tributaries

Herring Gull Larus argentatus Grange River and Dalgin River

Hooded Crow Corvus cornix Frequently recorded throughout surveyed reaches

House Martin Delichon urbicum Recorded around the River Clare and along a number

of tributaries

House Sparrow Passer domesticus Sinking, Dalgin, Grange and Killaclogher Rivers

Jackdaw Corvus monedula

Glennamaddy Turlough, Grange and Killaclogher

Rivers and on the River Clare around Claregalway

and Cloonmore Bridge

Kestrel Falco tinnunculus Killaclogher River, Grange River and around the River

Clare near Curraghmore Bridge

Lesser Whitethroat Sylvia curruca Glennamaddy Turlough

Long-tailed Tit Aegithalos caudatus Glennamaddy Turlough, Dalgin River and on the River

Clare around Cloonmore Bridge

Magpie Pica pica Frequently recorded throughout surveyed reaches.

Mallard Anas platyrhynchos Very frequently recorded throughout surveyed

reaches

Meadow Pipit Anthus pratensis Regularly recorded throughout surveyed reaches.

Mistle Thrush Turdus viscivorus Killaclogher River and Glennamaddy Turlough

Moorhen Gallinula chloropus Noted on a number of surveyed watercourses and

around the shores of Lough Corrib

Mute Swan Cygnus olor River Corrib and the River Clare

Pheasant Phasianus colchicus Frequently recorded throughout surveyed reaches.

Pied Wagtail Motacilla alba Recorded around the River Clare at Claregalway and

along a number of tributaries

Reed Bunting Emberiza schoeniclus On the River Clare, on the Dalgin and Grange Rivers

Reed Warbler Acrocephalus scirpaceus River Corrib

Robin Erithacus rubecula Frequently recorded throughout surveyed reaches.

Rook Corvus frugilegus Frequently recorded throughout surveyed reaches.

Sand Martin Riparia riparia Frequently recorded on the River Clare

Sedge Warbler Acrocephalus schoenobaenus Recorded in northern parts of the River Clare

catchment




Skylark Alauda arvensis Recorded from fields adjacent to the Clare in a

number of locations

Song Thrush Turdus philomelos Killaclogher, Grange River and Dalgin Rivers

Snipe Gallinago gallinago Around the small watercourses on the eastern shores of

Lough Corrib

Starling Sturnus vulgaris Frequently recorded throughout surveyed reaches.

Stonechat Saxicola rubicola On the River Clare and along the Grange and Dalgin

Rivers.

Swallow Hirundo rusitca Very regularly recorded throughout surveyed reaches.

Swift Apus apus Killaclogher River and at several locations along the

River Clare

Willow Tit Poecile montanus Grange River

Woodpigeon Columba palumbus Frequently recorded throughout surveyed reaches.

Wren Troglodytes troglodytes Frequently recorded throughout surveyed reaches.

Yellow Wagtail Motacilla flava Killaclogher River

Yellowhammer Emberiza citrinella Yellow River and on the River Clare

Table 4-29 Bird Species Recorded in Corrib Headford Arterial Drainage Scheme


Blackbird Turdus merula Frequently recorded throughout surveyed reaches.

Black-headed Gull Chroicocephalus ridibundus Black River and around the eastern shores of Lough

Corrib

Chaffinch Fringilla coelebs Finisklin area and along the Cornamona River

Chiffchaff Phylloscopus collybita Cornamona River

Cormorant Phalacrocorax carbo Black River

Crow Corvus corone Frequently recorded throughout surveyed reaches.

Dipper Cinclus cinclus Oughterard area

Goldfinch Carduelis carduelis Frequently recorded throughout surveyed reaches.

Great Tit Parus major Frequently recorded throughout surveyed reaches.

Grey Heron Ardea cinerea Black River and in the small watercourses around eastern

shores of Lough Corrib

Grey Wagtail Motacilla cinerea Oughterard area, Black River and Cornamona River

Herring Gull Larus argentatus Black River

Hooded Crow Corvus cornix Frequently recorded throughout surveyed reaches.

House Martin Delichon urbicum Around the eastern shores of Lough Corrib

Kestrel Falco tinnunculus Cornamona River

Mallard Anas platyrhynchos Frequently recorded throughout surveyed reaches.

Magpie Pica pica Frequently recorded throughout surveyed reaches.

Meadow Pipit Anthus pratensis Cornamona River

Mistle Thrush Turdus viscivorus Cloughmoyne area

Moorhen Gallinula chloropus Around the eastern shores of Lough Corrib

Mute Swan Cygnus olor Oughterard area and Drimneen River

Pheasant Phasianus colchicus Frequently recorded throughout surveyed reaches.

Pied Wagtail Motacilla alba Drimneen River

Reed Bunting Emberiza schoeniclus Around the eastern shores of Lough Corrib

Robin Erithacus rubecula Frequently recorded throughout surveyed reaches.

Sedge Warbler Acrocephalus schoenobaenus Cornamona River




Snipe Gallinago gallinago Black River near Barnaboy

Sparrowhawk Accipiter nisus Breeding pair and nest site identified near Owenriff

River

Stonechat Saxicola rubicola Cloughmoyne area and Cornamona River

Swallow Hirundo rusitca Regularly recorded throughout surveyed reaches

Woodpigeon Columba palumbus Frequently recorded throughout surveyed reaches

Wren Troglodytes troglodytes Frequently recorded throughout surveyed reaches

Table 4-30 Bird Species Recorded in Corrib Mask Arterial Drainage Scheme


Blackbird Turdus merula Frequently recorded throughout surveyed reaches

Common Whitethroat Sylvia communis Derrew area, Bunnadober River and Pollelmagur Lake

Dunnock Prunella modularis Frequently recorded throughout surveyed reaches

Grey Heron Ardea cinerea Ballintober area

Grey Wagtail Motacilla cinerea Srah and Kilglassan/Caheravoostia Turlough areas

Goldfinch Carduelis carduelis Keel River

Grasshopper Warbler Locustella naevia Bunnadober River

Hooded Crow Corvus cornix Bunnadober River

Long-tailed Tit Aegithalos caudatus Pollelmagur Lak

Mallard Anas platyrhynchos Frequently recorded throughout surveyed reaches

Meadow Pipit Anthus pratensis Bunnadober River

Mute Swan Cygnus olor Ballintober area

Reed Bunting Emberiza schoeniclus Kilglassan/Caheravoostia Turlough

Robin Erithacus rubecula Frequently recorded throughout surveyed reaches

Sedge Warbler Acrocephalus schoenobaenus Keel and Bunnadober Rivers, Pollelmagur Lake and

Annagh area

Skylark Alauda arvensis Srah area and Bunnadober River

Snipe Gallinago gallinago Kilkeeran area and Bunnadober River

Starling Sturnus vulgaris Kilglassan/Caheravoostia Turlough

Stonechat Saxicola rubicola Annagh and Kilglassan/Caheravoostia Turlough areas

Swallow Hirundo rusitca Frequently recorded throughout surveyed reaches

Swift Apus apus Keel River, Creagh Demesne and Kilkeeran areas

Wren Troglodytes troglodytes Frequently recorded throughout surveyed reaches



5 Appropriate Assessment

5.1 Introduction

The following chapter assesses the proposed drainage maintenance activities on those channels and embankments

screened into the assessment (see section 3) in relation to the European sites detailed in Section 4.

5.2 Identification of Potential Sources of Impact

This section further examines the source > pathway > receptor chains that could potentially result in adverse

impacts arising on the screened in European sites in the Corrib Arterial Drainage Scheme; this is informed

primarily by Ryan Hanley (2014c).

Table 3-1 details which of the possible pathways of impact (i.e. surface water, land and air, or groundwater)

have been identified as potentially affecting each of the screened in European sites.

Figure 3-13 illustrates which of the channels, embankments and structures within the Corrib Arterial Drainage

Scheme are those which could potentially impact upon the identified European sites and are consequently

screened into the assessment; all other channels, embankments and structures within the Corrib Arterial Drainage

Scheme have been screened out of the assessment.

Drainage Maintenance Activities include the following (to be carried out on each sub-catchment within the

programme):

▪ Headford: A - Silt and vegetation management; B - Aquatic vegetation cutting; D - Bush

cutting/Branch trimming; E - Tree Cutting; F- Other

▪ Clare: A - Silt and vegetation management; B - Aquatic vegetation cutting; C – Bank protection;

D - Bush cutting/Branch trimming; E - Tree Cutting; F- Other

▪ Mask: A - Silt and vegetation management; B - Aquatic vegetation cutting; C – Bank protection;

D - Bush cutting/Branch trimming; E - Tree Cutting; F- Other

5.2.1 Potential Sources of Impact via Surface Water Pathways

Nineteen European sites were identified as potentially being impacted upon via surface water pathways, this

includes 15 SACs and four SPAs. However, for many of the sites not all the qualifying interests/special

conservation interests present will be impacted upon by surface water pathways, as detailed in Table 5-1 below.

Table 5-1Qualifying Interests/Special Conservation Interests on screened in European sites likely to be impacted

upon via surface water

European Site (Site

Code)

Qualifying Interests/ Special Conservation

Interests likely to be affected by drainage

maintenance activities via Surface Water

Pathways


Interests not likely to be affected

Carrowkeel

Turlough SAC

(000475)

- Turloughs None

Clyard Kettle-holes

SAC

(000480)

- Turloughs

- Calcareous fens with Cladium mariscus

and species of the Caricion davallianae

None

Connemara

Bog Complex

- Salmon Salmo salar

- Otter Lutra lutra

- Marsh fritillary Euphydryas aurinia

- Coastal lagoons



European Site (Site

Code)




Pathways



SAC (002034) - Slender naiad Najas flexilis

- Oligotrophic waters containing very few

minerals of sandy plains (Littorelletalia

uniflorae)

- Natural dystrophic lakes and ponds

- Water courses of plain to montane levels

with the Ranunculion fluitantis and

Callitricho Batrachion vegetation

- Alkaline fens

- Reefs

- Northern Atlantic wet heaths with Erica

tetralix

- European dry heaths

- Molinia meadows on calcareous, peaty

or claveysilt-laden soils (Molinion

caeruleae)

- Blanket bog (*active only)

- Transition mires and quaking bogs

- Depressions on peat substrates of the

Rhynchosporion

- Old sessile oak woods with Ilex and

Blechnum in British Isles

Galway Bay

Complex SAC

(000268)

- Mudflats and sandflats not covered by


- Large shallow inlets and bays

- Otter Lutra lutra

- Coastal lagoons

- Reefs

- Perennial vegetation of stony banks

- Salicornia and other annuals colonizing

mud and sand

- Atlantic salt meadows (Glauco-

Puccinellietalia maritimae)

- Common seal Phoca vitulina

- Mediterranean salt meadows

(Juncetalia maritimi)

- Turloughs

- Juniperus communis formations on

heaths or calcareous grasslands

- Semi-natural dry grasslands and

scrubland facies on calcareous

substrates (Festuco Brometalia)


- Calcareous fens with (Cladium mariscus)

and species of the Caricion

davallianae

- Alkaline fens

Kilglassan/

Caheravoostia

Turlough

Complex SAC

(000504)

- Turloughs None

Levally Lough SAC

(000295)

- Turloughs None

Lisnageeragh

Bog and

Ballinastack

Turlough SAC

- Turloughs - Active raised bogs

- Degraded raised bogs still capable of

natural regeneration




European Site (Site

Code)




Pathways



(000296) - Rhynchosporion

Lough Carra/

Mask Complex

SAC (001774)

- Otter Lutra lutra



uniflorae)

- Hard oligo-mesotrophic waters with

benthic vegetation of Chara spp



- Alkaline fens

- Alluvial forests with Alnus glutinosa and

Fraxinus excelsior (Alno-Padion, Alnion

incanae, Salicion albae)

- Lesser horseshoe bat Rhinolophus

hipposideros

- Slender Green Feather Moss







- Limestone pavements

Lough Corrib SAC

(000297)

- Freshwater pearl mussel Margaritifera

margaritifera

- White-clawed crayfish Austropotamobius

pallipes

- Sea lamprey Petromyzon marinus

- Brook lamprey Lampetra planeri


- Otter Lutra lutra

- Slender naiad Najas flexilis



uniflorae)


benthic vegetation of Chara spp.



Callitricho-

- Batrachion vegetation



Petrifying springs with tufa formation

(Cratoneurion)

- Alkaline fens

- Bog woodland


hipposideros









caeruleae)

- Active raised bogs




Rhynchosporion




Lough Lurgeen

Bog/

Glenamaddy

Turlough SAC

(000301)

- Turloughs - Active raised bogs




Rhynchosporion

Maumturk

Mountains SAC

(002008)

- Salmon Salmo salar - Slender naiad Najas flexilis



European Site (Site

Code)




Pathways



- Oligotrophic waters containing very




tetralix

- Alpine and Boreal heaths



Rhynchosporion

- Siliceous rocky slopes with

chasmophytic vegetation

Mocorha Lough

SAC (001536)



None

Ross Lake And

Woods SAC

(001312)

- Otter Lutra lutra


benthic vegetation of Chara spp.

- Alkaline fens





hipposideros



caeruleae)

Shrule

Turlough SAC

(000525)

- Turloughs None

Williamstown

Turloughs SAC

(002296)

- Turloughs None

Inner Galway

Bay SPA

(004031)

- Great Northern Diver Gavia immer

[A003]

- Grey Heron Ardea cinerea [A028]

- Light-bellied Brent Goose Branta bernicla

hrota [A046]

- Wigeon Anas penelope [A050]

- Teal Anas crecca [A052]

- Shoveler Anas clypeata [A056]

- Red-breasted Merganser Mergus serrator

[A069]

- Ringed Plover Charadrius hiaticula

[A137]

- Golden Plover Pluvialis apricaria [A140]

- Lapwing Vanellus vanellus [A142]

- Dunlin Calidris alpina [A149]

- Bar-tailed Godwit Limosa lapponica

[A157]

- Curlew Numenius arquata [A160]

- Redshank Tringa totanus [A162]

- Cormorant Phalacrocorax carbo [A017]

- Sandwich Tern Sterna sandvicensis

[A191]

- Common Tern Sterna hirundo [A193]



European Site (Site

Code)




Pathways



- Turnstone Arenaria interpres [A169]

- Black-headed Gull Chroicocephalus

ridibundus [A179]

- Common Gull Larus canus [A182]

- Wetlands & Waterbirds [A999]

Lough Carra SPA

(004051)

- Common Gull Larus canus [A182] None

Lough Corrib

SPA (004042)

- Greenland White-fronted Goose Anser

albifrons flavirostris [A395]

- Gadwall Anas strepera [A051]


- Pochard Aythya ferina [A059]

- Tufted Duck Aythya fuligula [A061]

- Common Scoter Melanitta nigra [A065]

- Coot Fulica atra [A125]


ridibundus [A179]



- Arctic Tern Sterna paradisaea [A194]

- Hen Harrier Circus cyaneus [A082]

Lough Mask SPA

(004062



ridibundus [A179]


- Lesser Black-backed Gull Larus fuscus

[A183] Common Tern Sterna hirundo

[A193]




None

The following sources of impact are identified as potentially impacting upon the above European sites through

surface water pathways:

▪ Release of suspended solids - this can arise from a variety of drainage maintenance activities, including

removal of in-stream silt and vegetation, aquatic vegetation cutting, and bush cutting, branch trimming and

tree cutting. It can impact on surface water dependent habitats indirectly through increased turbidity, which

can reduce photosynthesis levels. It can also impact indirectly on waterbirds of special conservation interest

by affecting food chains from reduced water clarity and reduced photosynthesis which can affect aquatic

invertebrate diversity (i.e. the food source of the waterbirds). This source of impact is not considered

applicable to the Connemara Bog Complex SAC, Lisnageeragh Bog and Ballinastack Turlough SAC, Mocorha

Lough SAC and Williamstown Turloughs SAC as these sites are located upstream of where maintenance works

will be conducted; any suspended solids potentially released from drainage maintenance activities will be

downstream of these sites and will be carried away from them via surface water flows.



▪ Release or changes in nutrient levels - this can arise from a variety of drainage maintenance activities,

including removal of in-stream silt and vegetation, aquatic vegetation cutting and bush cutting, branch

trimming and tree cutting. It can impact on surface water dependent habitats indirectly through causing

eutrophication. It can also impact indirectly on waterbirds of special conservation interest by affecting food

chains through increased algal growth and decreased invertebrate and algal diversity (i.e. the food source

of the waterbirds). This source of impact is not considered applicable to the Connemara Bog Complex SAC,

Lisnageeragh Bog and Ballinastack Turlough SAC, Mocorha Lough SAC and Williamstown Turloughs SAC as

these sites are located upstream of where maintenance works will be conducted; any nutrients potentially

released from drainage maintenance activities will be downstream of these sites and will be carried away

from them via surface water flows

▪ Changes in water levels/channel morphology - this can arise from a variety of drainage maintenance

activities, including removal of in-stream silt and vegetation, aquatic vegetation cutting and bush cutting,

branch trimming and tree cutting. It can occur from maintenance activities that deepen and wide the channel

back to the original design level. This can impact on surface water dependent habitats indirectly through

increased capacity and flow in the channel leading to hydrological impacts. It can also impact on waterbirds

of special conservation interest through causing a loss of suitable habitat and impacting upon food chains.

Table 5-2 Potential Sources of Impact via Surface Water Pathways

Potential Sources of Impact Vulnerable European Site

Release of suspended solids

Release or changes in nutrient

levels/pollutants

Changes in levels/channel morphology

Carrowkeel Turlough SAC (000475)

Clyard Kettle-Holes SAC (000480)

Galway Bay Complex SAC (000268)

Kilglassan/ Caheravoostia Turlough Complex SAC (000504)

Levally Lough SAC (000295)

Lough Carra/ Mask Complex SAC (001774)

Lough Corrib SAC (000297)

Lough Lurgeen Bog/ Glenamaddy Turlough SAC (000301)

Maumturk Mountains SAC (002008)

Ross Lake and Woods SAC (001312)

Shrule Turlough SAC (000525)

Inner Galway Bay SPA (004031)

Lough Carra SPA (004051)

Lough Corrib SPA (004042)

Lough Mask SPA (004062

Connemara Bog Complex SAC (002034)

Lisnageeragh Bog and Ballinastack Turlough SAC (000296)

Mocorha Lough SAC (001536)

Williamstown Turloughs SAC (002296)

Maintenance works on bridges and sluices located on the above channels and embankments are similarly

considered to result in potential adverse effects. Maintenance works on bridges and sluices incudes routine works

(clearance of vegetation, repointing, parapet repair etc), full replacement or extensive rehabilitation is not

included in the assessment.



5.2.2 Potential Sources of Impact via Land and Air Pathways

Nineteen European sites were identified as potentially being impacted upon via land and air pathways; 15 SACs

and 4 SPAs. However, for many of the sites not all the qualifying interests/special conservation interests present

will be impacted upon by land and air pathways, as detailed in Table 5-3 below.

Table 5-3 Qualifying Interests/Special Conservation Interests on screened in European sites likely to be impacted

upon via land and air pathways

European Site (Site

Code)

Qualifying Interests/ Special

Conservation Interests likely to be

affected by drainage maintenance

activities via Land and Air Pathways


Conservation Interests not likely to

be affected

Carrowkeel Turlough SAC

(000475)

- Turloughs None

Cloughmoyne SAC

(000479)

- Limestone pavements None


(000480)

- Turloughs

- Calcareous fens with Cladium mariscus and

species of the Caricion davallianae

- Bog woodland

None

Connemara Bog

Complex SAC

(002034)



- Otter Lutra lutra



CallitrichoBatrachion vegetation


tetralix


- Molinia meadows on calcareous, peaty or

clavey-silt-laden soils (Molinion caeruleae)




Rhynchosporion

- Alkaline fens

- Coastal lagoons

- Reefs


- Oligotrophic waters containing

very few minerals of sandy plains


- Natural dystrophic lakes and

ponds

- Old sessile oak woods with Ilex

and Blechnum in British Isles



European Site (Site

Code)







be affected

Galway Bay Complex SAC

(000268)

- Mudflats and sandflats not covered by


- Otter Lutra lutra

- Coastal lagoons


- Reefs

- Perennial vegetation of stony

banks

- Salicornia and other annuals

colonizing mud and sand






- Turloughs







- Calcareous fens with (Cladium

mariscus) and species of the


- Alkaline fens

Kilglassan/

Caheravoostia

Turlough Complex

SAC (000504)

- Turloughs None

Levally Lough SAC

(000295)

- Turloughs None


Ballinastack

Turlough SAC

(000296)



- Turloughs


- Depressions on peat substrates of

the Rhynchosporion

Lough Carra/ Mask

Complex SAC

(001774)

- Otter Lutra lutra






- Alkaline fens






hipposideros




- Hard oligo-mesotrophic waters

with benthic vegetation of Chara

spp.







European Site (Site

Code)







be affected



margaritifera


pallipes





hipposideros

- Otter Lutra lutra





Callitricho-Batrachion vegetation

- Semi-natural dry grasslands and scrubland

facies on calcareous substrates (Festuco

Brometalia) (*important orchid sites)







Rhynchosporion


- species of the Caricion davallianae

Petrifying springs with tufa formation

(Cratoneurion)

- Alkaline fens


- Bog woodland







spp.

- Old sessile oak woods with Ilex

and Blechnum in British Isles

Lough Lurgeen Bog/

Glenamaddy

Turlough SAC

(000301)

- Turloughs





Rhynchosporion

None


(002008)

- Salmon Salmo salar - Slender naiad Najas flexilis




- Northern Atlantic wet heaths with

Erica tetralix




European Site (Site

Code)







be affected


- Depressions on peat substrates of

the Rhynchosporion



Monivea Bog SAC (002352)





Rhynchosporion

None

Ross Lake And

Woods SAC (001312)

- Otter Lutra lutra



- Alkaline fens





hipposideros



spp.

Shrule Turlough SAC

(000525)

- Turloughs None


(004031)

- Curlew Numenius arquata [A160] - Great Northern Diver Gavia

immer [A003]

- Cormorant Phalacrocorax carbo

[A017]


- Light-bellied Brent Goose Branta

bernicla hrota [A046]




- Red-breasted Merganser Mergus

serrator [A069]


[A137]

- Golden Plover Pluvialis apricaria

[A140]



- Bar-tailed Godwit Limosa

lapponica [A157]


- Turnstone Arenaria interpres

[A169]

- Black-headed Gull

Chroicocephalus ridibundus [A179]




European Site (Site

Code)







be affected


[A191]

- Common Tern Sterna hirundo

[A193]


Lough Carra SPA (004051) - Common Gull Larus canus [A182] None












ridibundus [A179]




Wetlands

None




ridibundus [A179]



[A183]


Greenland White-fronted Goose Anser



None


land and air pathways:

▪ Physical disturbance of habitats (and loss of wood vegetation cover) - this can arise from a variety of

drainage maintenance activities, including removal of in-stream silt and vegetation, aquatic vegetation

cutting and bush cutting, branch trimming and tree cutting. It can impact on habitats (terrestrial, surface water

dependent and groundwater dependent) directly, although temporarily, as a result of machines tracking

along the bankside and as a result of the deposition of spoil on the bankside. This can result in a loss of

habitat from in-stream/bankside areas and maintenance access corridors, direct mortalities or the

displacement of sensitive species. It can also impact on waterbirds of special conservation interest through

machines tracking along the banskide, reducing vegetation as a food source.



▪ Noise and visual disturbance - this can arise from a variety of drainage maintenance activities, including

removal of in-stream silt and vegetation, aquatic vegetation cutting and bush cutting, branch trimming, tree

cutting and other activities such as gravel removal. It can occur as a result of noise emissions and visual

disturbance from machinery and the presence of machine drivers and other OPW staff. It can result in the

flight and displacement of sensitive species from suitable habitat locations. It is not considered relevant in

relation to designated habitat types, although it is relevant for the species which these habitats support.

Table 5-4 Potential Sources of Impact via Land and Air Pathways

Potential Sources of Impact Vulnerable European Sites

Physical disturbance of habitats

(and loss of wood vegetation cover)

Noise and visual disturbance









Lough Carra SPA (004051)



Physical disturbance of habitats

(and loss of wood vegetation cover)

(no species qualifying interests so no

potential for impacts by noise and

visual disturbance)


Cloughmoyne SAC (000479)







Works on bridges and sluices located on the above channels and embankments are similarly considered to result

in potential adverse effects.

5.2.3 Potential Sources of Impact via Groundwater Pathways

Twenty-three European sites were identified as potentially being impacted upon via groundwater pathways; 19

SACs and 4 SPAs. However, for many of the sites not all the qualifying interests/special conservation interests

present will be impacted upon by groundwater pathways, as detailed in Table 5-5 below.

Table 5-5 Qualifying Interests/Special Conservation Interests on screened in European sites likely to be impacted

upon via groundwater pathways

European Site (Site

Code)



maintenance activities via Groundwater

Pathways


Conservation Interests not likely to be

affected

Ardkill Turlough SAC

(000461) - Turloughs None

Ballymaglancy Cave,

Cong SAC (000474)


hipposideros

- Caves not open to the public

None



European Site (Site

Code)




Pathways



affected

Carrowkeel Turlough

SAC (000475) - Turloughs None


(000480)

- Turloughs


species of the Caricion davallianae Bog

woodland

None

Connemara Bog

Complex SAC

(002034)


- Alkaline fens



- Coastal lagoons

- Reefs

- Otter Lutra lutra





- Natural dystrophic lakes and ponds

- Water courses of plain to montane

levels with the Ranunculion fluitantis

and CallitrichoBatrachion vegetation


tetralix


- Molinia meadows on calcareous,

peaty or clavey-silt-laden soils

(Molinion caeruleae)



Rhynchosporion



Galway Bay Complex

SAC (000268) - Coastal lagoons

- Mudflats and sandflats not covered

by seawater at low tide


- Reefs

- Perennial vegetation of stony banks

- Salicornia and other annuals

colonizing mud and sand



- Otter Lutra lutra




- Turloughs



European Site (Site

Code)




Pathways



affected







- Calcareous fens with (Cladium

mariscus) and species of the Caricion

davallianae

- Alkaline fens

Greaghans Turlough

SAC (000503) - Turloughs None

Kilglassan/

Caheravoostia

Turlough Complex

SAC (000504)

- Turloughs None

Levally Lough SAC



Ballinastack

Turlough SAC

(000296)

- Turloughs





Rhynchosporion

Lough Carra/ Mask

Complex SAC

(001774)

- Slender Green Feather Moss Drepanocladus

vernicosus



uniflorae)

- Hard oligo-mesotrophic waters with benthic




- Alkaline fens





hipposideros

- Otter Lutra lutra







Lough Corrib SAC

(000297)


pallipes


hipposideros



uniflorae)




margaritifera




- Otter Lutra lutra






European Site (Site

Code)




Pathways



affected










Rhynchosporion


- species of the Caricion davallianae

- Petrifying springs with tufa formation

(Cratoneurion)

- Alkaline fens

- Bog woodland








Lough Lurgeen Bog/

Glenamaddy

Turlough SAC

(000301)

- Turloughs





Rhynchosporion

Maumturk Mountains

SAC (002008)



Rhynchosporion







tetralix




Monivea Bog SAC

(002352)





Rhynchosporion

Ross Lake And

Woods SAC (001312)





- Alkaline fens





hipposideros

- Otter Lutra lutra

Shrule Turlough SAC


Towerhill House SAC

(002179)


hipposideros None



European Site (Site

Code)




Pathways



affected


(004031)

- Cormorant Phalacrocorax carbo [A017]

- Light-bellied Brent Goose Branta bernicla

hrota [A046]



- Red-breasted Merganser Mergus serrator

- [A069]




- Great Northern Diver Gavia immer

[A003]




[A137]

- Golden Plover Pluvialis apricaria

[A140]


- Bar-tailed Godwit Limosa lapponica

[A157]

- Curlew Numenius arquata [A160]

- Turnstone Arenaria interpres [A169]


ridibundus [A179]



[A191]


Lough Corrib SPA

(004042)











Wetlands



ridibundus [A179]


Lough Mask SPA

(004062



Greenland White-fronted Goose Anser

- albifrons flavirostris [A395]



ridibundus [A179]



[A183]


groundwater pathways:

▪ Release of suspended solids - this can arise from a variety of drainage maintenance activities, including

removal of in-stream silt and vegetation, aquatic vegetation cutting and bush cutting, branch trimming and

tree cutting. It can impact on groundwater dependent habitats indirectly through increased turbidity, which

can reduce photosynthesis levels. It can also impact indirectly on waterbirds of special conservation interest

by affecting food chains from reduced water clarity and reduced photosynthesis which can affect aquatic

invertebrate diversity (i.e. the food source of the waterbirds).



▪ Release or changes in nutrient levels - this can arise from a variety of drainage maintenance activities,

including removal of in-stream silt and vegetation, aquatic vegetation cutting and bush cutting, branch

trimming and tree cutting. It can impact on groundwater dependent habitats indirectly through causing

eutrophication (from mobile inorganics NO3 and low mobility inorganics PO4), which could impact on

groundwater from aquifer recharge. It could also impact indirectly on waterbirds of special conservation

interest by affecting food chains through increased algal growth and decreased invertebrate and algal

diversity (i.e. the food source of the waterbirds)

▪ Changes in water levels/channel morphology - this can arise from a variety of drainage maintenance

activities, including removal of in-stream silt and vegetation, aquatic vegetation cutting and bush cutting,

branch trimming and tree cutting. It can also occur from maintenance activities that deepen and wide the

channel back to the original design level. This can impact on groundwater dependent habitats indirectly

through:

- Increased capacity and flow in the channel leading to a reduction in water levels and

hydrogeological impacts.

- Direct aquifer recharge from a stream bed in karst/fissured aquifer.

- Lowering of channel water levels due to increased channel conveyance, which can increase

the hydraulic gradient between the bankside unconfined groundwater table. This can

potentially increase discharge to the channel and change the absolute value and pattern of

variation in groundwater levels and potentially the location of groundwater divides. The

distance from the channel at which an impact occurs is dependent on the subsoil and bedrock

aquifer characteristics.

It can also impact on waterbirds of special conservation interest through causing a loss of suitable habitat and

impacting upon food chains.

Table 5-6 Potential Sources of Impact via Groundwater Pathways

Potential Sources of Impact Vulnerable EuropeanSites

Release of suspended solids

Release or changes in nutrient levels

Changes in water

levels/channel morphology

Ardkill Turlough SAC (000461)

Ballymaglancy Cave, Cong SAC (000474)





Greaghans Turlough SAC (000503)











Towerhill House SAC (002179)




Potential Sources of Impact Vulnerable EuropeanSites


Lough Mask SPA (004062)

Works on bridges and sluices located on the above channels and embankments are similarly considered to result

in potential adverse effects.

5.3 Impact Assessment

Table 5-7 assesses each of the screened in European sites in more detail and examines where potentially adverse

impacts may arise from the sources of impact identified above. Where potentially significant adverse impacts

are identified, avoidance and mitigation measures are proposed to offset these impacts.

5.3.1 Do nothing impact

Should the Corrib drainage works not be carried out at this site, it is likely that natural succession would occur

throughout the location. This is likely to include increased sedimentation in the channels over time, and increased

vegetation growth along channel edges and on the islands. Reduction in channel width due to increase size of

vegetated islands, may slow the flow of water and cause flooding in susceptible areas during periods of high

rainfall. Erosion occurring along the edge of the banks may contribute further to the sediment loading.

5.3.2 In-combination Effects

Projects and Plans that have the potential to contribute in-combination impacts and cumulative impacts upon

European designated sites are considered in this section, as described in the Guidelines for the Assessment of

Indirect and Cumulative Impacts, as well as Impact Interactions (Walker and Johnston 1999). Key points to

consider when assessing cumulative and in-combination impacts include the nature and scale of the potential

impacts including their potential magnitude and significance, the availability and quality of data and the impacts

that may have occurred with similar projects in the area, where available or observed. Potential sources of in-

combination effects identified as part of this assessment include:

Agricultural activities: Farmers and landowners may also undertake general agricultural operations in areas

adjacent to the rivers and drainage ditches included in the proposed Corrib drainage maintenance works, which

could potentially give rise to impacts of a similar nature to those arising from the planned OPW works. This could

potentially result in additional periods of disturbance and a risk to water quality. Many agricultural operations

are periodic, not continuous in nature, and qualify as a Notifiable Action that requires consultation with NPWS

in advance of the works e.g. reclamation, infilling or land drainage within 30m of the river, removal of trees or

any aquatic vegetation within 30m of the river, and harvesting or burning of reed or willow (NPWS 2019).

Agricultural operations must also comply with the EC (Environmental Impact Assessment) (Agriculture) Regulations

2011 and amendment 2017 S.I. No. 456/2011 and 407/2017 in relation to activities covered by the

regulations:

▪ restructuring of rural land holdings,

▪ commencing use of uncultivated land or semi-natural areas for intensive,

▪ land drainage works on lands used for agriculture.

A NIS is required under Regulation 9 if it is likely to have a significant effect on a Natura 2000 site. The drainage

or reclamation of wetlands is controlled under the Planning and Development (Amendment) (No. 2) Regulations

2011 and the European Communities (Amendment to Planning and Development) Regulations 2011. Therefore,

the in-combination effects of the proposed works and agricultural operations is not likely to be significant.



OPW arterial drainage maintenance operations: Maintenance operations have been ongoing since the

construction of the schemes following the 1945 Arterial Drainage Act, potentially resulting in adverse cumulative

effects. However, as the maintenance operations are undertaken to restore the design level only, the hydrological

and hydrogeological impact should be no greater than originally occurred upon the scheme's construction; no

further deepening or widening will occur. On a regional scale, neighbouring Arterial Drainage Schemes could

be considered to have an adverse impact on European sites, particularly where large sites fall across two, or

more scheme areas. However, this is not considered to be an issue for the Corrib Scheme works. The closest

schemes are on the Moy and Boyle Schemes which are located to the north and north-east of the Corrib scheme

respectively. The Corrib Scheme is within a separate surface water catchment and separate groundwater body

so the potential for adverse in-combination impacts are minimal. Thus, the potential for adverse in-combination

impacts from either of these schemes are minimal. Appropriate Assessment screening exercises have been

conducted for both the Moy and Boyle schemes (JBA Consulting, 2016b and 2014c). Neither screening exercise

for the Moy or Boyle identified likely significant effects on any European Site identified in the Corrib Scheme

Appropriate Assessment. As no adverse impacts will arise on this site from works in the Moy and Boyle drainage

schemes no cumulative or in-combination effects with works in the Corrib scheme can arise.

The Galway County Development Plan 2015-2021 aims to adopt a precautionary principle in respect of

development proposal where significant environmental implications are involved and recognise the importance

of Galway’s natural heritage. A NIR was completed for the Plan identifying threats to the the European Sites

identified within this document and objectives of the plan which have potential impact on the protection of these

European Sites. Cumulative and in combination effects were also considered in relation to other plans and

programmes of relevance as set out in the NIR of the CDP. Therefore, considering the Plan and Measures included

to the CDP to prevent impact, it was found that no direct, indirect or cumulative significant effects on the Natura

2000 network of sites or its integrity were likely to occur.

The River Basin Management Plan for Ireland 2018-2021 sets out the actions that Ireland will take to improve

water quality and achieve ‘good’ ecological status in water bodies (rivers, lakes, estuaries and coastal waters)

by 2027. The Corrib River has been classified as "Probably at risk", however the River Basin Management Plan

for Ireland 2018-2021 aims to improve the management and water quality in Ireland.

Spread of non-native invasive species Aquatic non-native invasive species in particular Japanese Knotweed,

Zebra Mussel and crayfish plague, have been identified as being present within the Corrib catchment (Clare

River has been confirmed to be contaminated with Crayfish Plague). Terrestrial non-native invasive species that

have been confirmed in the vicinity include Japanese Knotweed. Given the surface water and land connectivity,

potential in-combination impacts from the re-use of unclean equipment, machinery or clothing, used on nearby

schemes or projects, or stored nearby in potentially contaminated areas, cannot be ruled out. Equipment,

machinery or boots that are being used in the water in nearby schemes or works within potentially contaminated

areas could carry microscopic spores or larvae that if used at this location, can cause the spread of aquatic non-

native invasive species.

The spread of crayfish plague around Ireland is having detrimental impacts to native crayfish populations and

must be prevented (Waterways Ireland 2017). The Clare River, where crayfish plague has been confirmed is

part of the Corrib catchment. As non-native invasive species spread in other areas around this scheme,

uncontaminated refuges will become extremely important to the survival of the infected species. The spread of

crayfish plague and Japanese knotweed in particular must be prevented. Therefore, considering the nature,

scale and types of non-native invasive species in this area, and given the types of potential impacts there is

potential for cumulative decrease in the area of suitable habitats in this site as a result of the spread of non-

native invasive species. While the normal operation of the proposed works includes the adherence to biosecurity

protocol, further, more specific mitigation will be required. Therefore, there may be significant impacts from the



proposed arterial drainage maintenance works in-combination with the use of the operational equipment and

machinery stored outside the area or used on other schemes and works outside the scheme area.

There are no other known plans/projects on-going or proposed (at the time of this study) which may give rise to

any form of cumulative impact on the European sites.

The OPW also undertake other capital and enhancement works beyond the scope of general maintenance works

outlined in section 2.2. It is understood that under the Environmental River Enhancement Programme (EREP), the

OPW is proposing to carry out channel improvement works on a 2.5km section of the Cross River (OPW Channel

CH8 Sect. 4, Sect. 5 and Sect. 6) in the Corrib Headford Arterial Drainage Scheme. The aim of the work is to

address long standing flooding issues within the catchment and to enhance in-stream habitats and morphology

(JBA Consulting, 2014b). An appropriate assessment screening exercise has been completed for these works,

which concluded that no significant effect, either as a result of the construction phase or following completion,

would arise via any of the three pathways. Whilst these works are of a relatively minor nature, aim to enhance

the watercourse habitat and alone are not likely to result in significant adverse impacts on the qualifying

interests/special conservation interests of the identified sites, in-combination with general arterial drainage

maintenance operations impacts may be significant. This will be considered in this Natura Impact Statement with

appropriate mitigation suggested.

Corrib Arterial Drainage Scheme - NIS


Table 5-7 Impact Prediction - Ardkill Turlough SAC (000461)

Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact

Pathway Impact on Attribute and Target Prior to Mitigation / Avoidance Avoidance / Mitigation Measures Residual

Impact

Turloughs* (3180)

Release of

suspended

solids

Release or

changes in

nutrient levels

Changes in

water levels/

channel

morphology

Groundwater

Drainage maintenance activities could impact on water quality in the

turlough through the release of suspended sediments and nutrients

which could potentially result in increased turbidity and

eutrophication, which could then result in algal blooms, through

aquifer recharge. This could then impact on vegetation structure and

composition and prevent achievement of the targets associated with

these attributes. Hydrology is the key driver of turlough ecology, with

different turlough communities, assemblages and species affected by

various hydrological attributes (NPWS, 2013w). Drainage

maintenance activities, such as silt and vegetation management and

aquatic vegetation cutting, or other activities such as gravel shoal

removal, can result in the deepening and widening of channels which

could impact on groundwater levels. As turloughs flood primarily as

a result of rising groundwater, any change could have adverse

impacts on turlough ecology and attributes, including habitat area,

distribution, vegetation composition/structure and typical species.

However, significant changes to the hydrogeological regime are

unlikely as the works will restore the system to the design standard

only. The drainage maintenance activities are therefore unlikely to

impact significantly on attributes used to define conservation status.

Follow Environmental Procedures in OPW (2019)-

specifically EP7 10 Steps to Environmentally Friendly

Maintenance, EP9 Trees and Vegetation

Management, EP10 Drainage Maintenance Silt

Management (specifically Point 2 where possible) and

EP17 Water Pollution. See Table 6-1

The above measures will control sediment mobilisation

and reduce the risk of pollution incidents thereby

reducing the potential significance of this source of

impact on the groundwater dependent habitat within

this SAC.

Follow protocols and EPs in OPW (2019) - specifically

EP7 Environmental Drainage Maintenace and the 10

Steps to Enviornmentally Friendly Maintenance.

See Table 6-1

This will ensure that drainage maintenance works do

not change water levels/channel morphology beyond

the existing design level, which has been in existence

since 1986

No



Table 5-8 Impact Prediction - Ballymaglancy Cave, Cong SAC 000474)

Qualifying

Interests/

Special

Conservation

Interests

Potential

Source of

Impact


Impact

Lesser

horseshoe bat

Rhinolophus

hipposideros

(1303)

Caves not

open to the

public (8310)

Release of

suspended

solids

Changes in

water levels/

channel

morphology

Groundwater

The cave habitats in Ballymaglancy Cave, Cong SAC, and the Lesser

horseshoe bat populations they support, are GWD, with a number of

features developing in the natural limestone cave including curtains and

other forms (NPWS, 2018) as a result of groundwater movement. Drainage

maintenance activities could impact on the cave habitats and the

groundwater-fed features currently forming through the release of

suspended sediments which can impact on groundwater. Being in a karstic

GWB, flow pathways of impact can operate over considerable distances.

However, given that the closest scheme watercourse is over 3km away, with

major watercourses (i.e. the Cong River) and topographical changes in

between, potential impacts are unlikely to be significant. Drainage

maintenance activities, such as silt and vegetation management and aquatic

vegetation cutting, or other activities such as gravel shoal removal, can also

result in the deepening and widening of channels which could impact on

groundwater levels and consequently the groundwater-fed features in the

cave habitats (and consequently the bat populations they support).

However, significant changes to the hydrogeological regime are unlikely as

the works will restore the system to the design standard only. The drainage

maintenance activities are therefore unlikely to impact significantly on

attributes used to define conservation status.



Maintenance and EP17 Water Pollution

See Table 6-1




impact on the groundwater dependent habitat, and the

bat species it supports, within this SAC

Follow protocols and EPs in OPW (2019) – specifically

EP26 and EP7 points 2.1 and 2.2 of Environmental

Drainage Maintenance Guidance Notes: 10 Steps to

Environmentally Friendly Maintenance.

This will ensure that drainage maintenance works do not

change water levels/channel morphology beyond the

existing design level, which has been in existence since

1986

No



Table 5-9 Impact Prediction - Carrowkeel Turlough SAC (000475)

Qualifying

Interests/

Special

Conservation

Interests

Potential

Source of

Impact


Impact

Turloughs*

(3180)

Release of

suspended

solids

Release or

changes in

nutrient levels

Changes in

water levels/

channel

morphology

Groundwater

Drainage maintenance activities could impact on water quality in the turlough

through the release of suspended sediments and nutrients which could potentially

result in increased turbidity and eutrophication, which could then result in algal

blooms. This could reach the turlough habitat through surface water pathways, or

through aquifer recharge via groundwater pathways. This could then impact on

vegetation structure and composition and prevent achievement of the targets

associated with these attributes. Hydrology is the key driver of turlough ecology,

with different turlough communities, assemblages and species affected by various

hydrological attributes (NPWS, 2013w). Drainage maintenance activities, such

as silt and vegetation management and aquatic vegetation cutting, or other

activities such as gravel shoal removal, can result in the deepening and widening

of channels which could impact on groundwater levels. As turloughs flood

primarily as a result of rising groundwater, any change in the levels of this could

have adverse impacts on turlough ecology and a number of attributes, including

habitat area, habitat distribution, vegetation composition and structure and

typical species. Additionally, whilst turloughs are GWD habitats, they do have

connectivity to surface waters, therefore changes in water levels and channel

morphology as a result of drainage maintenance activities on nearby

watercourses could also result in adverse impacts via surface water pathways.

However, significant changes to the hydrological and hydrogeological regime

are unlikely as the works will restore the system to the design standard only. The

drainage maintenance activities are therefore unlikely to impact significantly on






Management (specifically Point 2 where possible) and

EP17 Water Pollution See Table 6-1




impact on the groundwater dependent habitat within

this SAC.

Follow protocols and EPs in OPW (2019) - specifically

EP7 Environemntal Drainage Maintenancxe (EDM) and

points 2.1 and 2.2 of Environmental Drainage

Maintenance Guidance Notes: 10 Steps to

Environmentally Friendly Maintenance




since 1986

No



Table 5-10 Impact Prediction - Cloughmoyne SAC (000479)

Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

Limestone

pavements*

(8240)

Physical

disturbance of

habitats (and

loss of wood

vegetation

cover

Land

and Air

The limestone pavement habitat type for which this SAC is designated is

likely to be vulnerable to physical disturbance arising from drainage

maintenance activities through the direct removal of vegetation/substrate

within the maintenance access corridor. This could impact on a range of

attributes including habitat area and vegetation composition. Given that

maintenance activities are conducted along watercourses that have been

periodically subject to such activities, and that the bank of operation remains

consistent, there will be a working corridor along the channels which has been

subject to periodic physical disturbance and is consequently unlikely to

represent high quality habitat of these Annex I types.

Follow protocols and EPs in OPW (2019) –

specifically EP7 Environemntal Drainage

Maintenancxe (EDM) and points 1.1 and 1.2 of

Environmental Drainage Maintenance Guidance

Notes: 10 Steps to Environmentally Friendly

Maintenance to minimise the impacts of physical

disturbance arisings from drainage maintenance

works will be deposited on existing spoil heaps and

not on areas of species-rich calcareous grassland,

alkaline fen or calcareous heath habitat alongside

channel CH5 to ensure the species-richness is not

compromised. See Table 6-1

No



Table 5-11 Impact Prediction - Clyard Kettle-Holes SAC (000480)

Qualifying Interests/

Special Conservation

Interests

Potential

Source of

Impact


Impact

Turloughs* (3180)




davallianae (7210)

Release of

suspended

solids

Release or

changes in

nutrient

levels

Surface

Water

Groundwat

er

Turloughs, being groundwater fed, are typically associated with high water quality, with

naturally low dissolved nutrients, clear water and low algal growth (NPWS, 2013w).

Kilroy et al (2008) also identifies that turloughs are highly sensitive to changes in

groundwater chemistry and nutrient concentration. Additionally, calcareous fens with

Cladium mariscus require appropriate water quality to support the natural structure and

functioning of the habitat, generally receiving natural levels of nutrients (i.e. iron,

magnesium and calcium) from water sources, with generally low nitrogen and phosphorous

which can be limiting (NPWS,2013h). Drainage maintenance activities could impact on

water quality in the turlough, fen and bog woodland habitats through the release of

suspended sediments and nutrients which could potentially result in increased turbidity and

eutrophication, which could then result in algal blooms. This could reach these habitat types

through surface water pathways, or through aquifer recharge via groundwater pathways.

This could then impact on vegetation structure and composition and prevent achievement

of the targets associated with these attributes.

Follow Environmental Procedures in

OPW (2019)- specifically EP7 10

Steps to Environmentally Friendly

Maintenance, EP9 Trees and

Vegetation Management, EP10

Drainage Maintenance Silt

Management (specifically Point 2

where possible) and EP17 Water

Pollution. See Table 6-1

The above measures will control

sediment mobilisation and reduce the

risk of pollution incidents thereby

reducing the potential significance of

this source of impact on the

groundwater dependent habitat

within this SAC.

No

Changes in

water

levels/

channel

morpholog

y

Surface

Water

Groundwat

er

Hydrology is the key driver of turlough ecology, with different turlough communities,

assemblages and species affected by various hydrological attributes (NPWS, 2013w).

Calcareous fen habitats also require natural groundwater levels, surface water flows and

water table levels to maintain this habitat type (NPWS, 2013h). Drainage maintenance

activities, such as silt and vegetation management and aquatic vegetation cutting, or other

activities such as gravel shoal removal, can result in the deepening and widening of

channels which could impact on groundwater levels and surface water flows. This could

have adverse impacts on these habitats and a number of attributes, including habitat area,

habitat distribution, vegetation composition and structure and typical species. However,

significant changes to the hydrological and hydrogeological regime are unlikely as the

works will restore the system to the design standard only. The drainage maintenance

activities are therefore unlikely to impact significantly on attributes used to define

conservation status

Follow protocols and EPs in OPW

(2019) - specifically EP7

Environemntal Drainage

Maintenancxe (EDM) and points 2.1

and 2.2 of Environmental Drainage

Maintenance Guidance Notes: 10


Maintenance

See Table 6-1

This will ensure that drainage

maintenance works do not change

water levels/channel morphology

beyond the existing design level,

No





Interests

Potential

Source of

Impact


Impact

which has been in existence since

1986

Physical

disturbance

of habitats

(and loss of

wood

vegetation

cover

Land and

Air

The turlough and calcareous fen habitats for which this SAC is designated are likely to be

vulnerable to physical disturbance arising from drainage maintenance activities through

the direct removal of vegetation within the maintenance access corridor. This could impact

on a range of attributes including habitat area and vegetation composition. However,

given that maintenance activities are conducted along watercourses that have been

periodically subject to such activities, and that the bank of operation remains consistent,

there will be a working corridor along the channels which has been subject to periodic

physical disturbance and is consequently unlikely to represent high quality habitat of these

Annex I types.




Maintenance, EP9 Trees and

Vegetation Management, EP10

Drainage Maintenance Silt

Management (specifically Point 2

where possible) and EP17 Water

Pollution

See Table 6-1

No



Table 5-12 Impact Prediction - Connemara Bog Complex SAC (002034)


Conservation Interests

Potential

Source of

Impact

Pathway Impact on Attribute and Target Prior to Mitigation /

Avoidance Avoidance / Mitigation Measures

Residual

Impact

Natural dystrophic lakes and

ponds (3160)

Water courses of plain to



Callitricho-Batrachion

vegetation (3260)

Alkaline fens (7230)

Salmon Salmo salar (1106)

Otter Lutra lutra (1355)

Najas flexilis (1833)

Oligotrophic waters

containing very few minerals

of sandy plains (Littorelletalia

uniflorae) (3110)

Changes in

water levels/

channel

morphology

Surface

Water

The lake and fens are dependent on specific hydrological

regime attributes. The eutrophic lake is dependent on

natural water level fluctuation and water turbidity, while the

alkaline fens are dependent on natural hydrological

regimes to support the functioning of the habitat. The species

supported by these habitat types (i.e. Salmon, Otter and

Slender Naiad) are therefore also dependent on a specific

hydrological regime. Drainage maintenance activities, such

as silt and vegetation management and aquatic vegetation

cutting, or other activities such as gravel shoal removal, can

result in the deepening and widening of channels which could

impact on surface water flows. This could have adverse

impacts on these habitats and attributes, including habitat

area, distribution and vegetation composition. However,

significant changes to the hydrological regime are unlikely

as the works will restore the system to the design standard

only. The drainage maintenance activities are therefore

unlikely to impact significantly on attributes used to define

conservation status.

Follow protocols and EPs in OPW (2019) - specifically, the

procedures under EP7 Environemntal Drainage

Maintenancxe (EDM) and compliance with the 10-point plan

and auditing processes. Works should follow those as

describes in guidance under the EP10 Drainage

Maintenance Silt Management, including but not limited to

working upstream, skipping sections and leaving buffer

zones both instream and along the banks. Machinery

Related Procedures should be followed to include no

refuelling within 50m of a watercourse, use of

biodegradable oils, ensure availability of spill kits and

leave natural vegetation buffer strip along the bank.

See Table 6-1



existing design level, which has been in existence since 1986

No

Euphydryas aurinia (1065)

Salmo salar (1106)

Lutra lutra (1355)





vegetation (3260)

Northern Atlantic wet heaths

with Erica tetralix (4010)

Physical

disturbance of

habitats (and

loss of wood

vegetation

cover

Land and

Air

The terrestrial and riverine habitats for which the SAC is

designated are likely to be vulnerable to physical

disturbance arising from drainage maintenance activities

through the direct removal of vegetation within the

maintenance access corridor. This could impact on a range

of attributes including habitat area and vegetation

composition. For example, a key attribute used to define the

condition of watercourses with floating river vegetation is

riparian habitat and the maintenance of this; drainage

maintenance activities could impact on the extent of this.

Physical disturbance of habitats can also adversely impact

on the species within the SAC by removing cover for Otter,

Follow protocols and EPs in OPW (2019) - specifically EP7

Environemntal Drainage Maintenancxe (EDM) and point 1.1

of Environmental Drainage Maintenance Guidance Notes:

10 Steps to Environmentally Friendly Maintenance. When

maintenance works are carried out within the SAC and

potential wetland habitats (such as alkaline fens) are

present, minimiseor avoid maintenance as per the Wetland

EP31 should be followed.

See Table 6-1

Specific procedures relevant to Otter (EP20) and Salmonid

(EP19) should also be followed.

No





Potential

Source of

Impact



Residual

Impact

European dry heaths (4030)

Molinia meadows on

calcareous, peaty or clavey-silt-

laden soils (Molinion caeruleae)

(6410)

Blanket bog (*active only)

(7130)

Transition mires and quaking

bogs (7130)

Depressions on peat substrates

of the Rhynchosporion (7150)


the food plant of Marsh fritillary butterfly and potentially

damaging Salmon redds. However, given that maintenance

activities are conducted along watercourses that have been

periodically subject to such activities, and that the bank of

operation remains consistent, there will be a working

corridor along the channels which has been subject to

periodic physical disturbance and is consequently unlikely to

represent high quality habitat of these Annex I types.

Marsh fritillary Euphydryas

aurinia (1065)



Transition mires and quaking

bogs (7140)


Noise and

visual

disturbance

Land and

Air

The faunal species for which the SAC is designated, including

Marsh fritillary, Salmon and Otter will be sensitive to

disturbance from machinery and workforces conducting

drainage maintenance operations.

Follow protocols and EPs in OPW (2019) – specifically EP7

Environemntal Drainage Maintenancxe (EDM) and point 1.1

of Environmental Drainage Maintenance Guidance Notes:

10 Steps to Environmentally Friendly Maintenance.Specific

procedures relevant to Otter in the Otter Procedures EP20

include to check mapping and reporting of Otter holts and

walkover of the works area by Operational Staff one week

in advance. Where holts are observed, a buffer zone of

30m for general maintenance works should be applied, the

buffer may be increased depending on the nature of the

works (longer term construction works, 150m buffer.) See

Table 6-1

No

Release of

suspended solids

Ground

water

Transition mires and quaking bogs, and alkaline fens, being

groundwater fed, are dependent on appropriate water

quality. For example, alkaline fens receive natural levels of

nutrients (e.g. iron, magnesium and calcium) from water

sources, and are generally poor in nitrogen and


specifically EP7 Environemntal Drainage Maintenancxe

(EDM) and 10 Steps to Environmentally Friendly

Maintenance and EP17 Water Pollution.

No





Potential

Source of

Impact



Residual

Impact

Release or

changes in

nutrient levels

phosphorous which tend to be limiting nutrients (NPWS,

2013h). Drainage maintenance activities could impact on

water quality in these habitat types through the release of

suspended sediments and nutrients which could potentially

result in increased turbidity and eutrophication, which could

then result in algal blooms, through aquifer recharge. This

could then impact on vegetation structure and composition

and prevent achievement of the targets associated with

these attributes.

See Table 6-1

The above measures will control sediment mobilisation and

reduce the risk of pollution incidents thereby reducing the

potential significance of this source of impact on the

groundwater dependent habitat within this SAC.

Changes in

water levels/

channel

morphology

Groundw

ater

Maintenance of groundwater and water table levels within

natural ranges is essential for alkaline fen habitats (NPWS,

2015), and it is also considered important for transition

mires and quaking bogs. Drainage maintenance activities,

such as silt and vegetation management and aquatic

vegetation cutting, or other activities such as gravel shoal

removal, can result in the deepening and widening of

channels which could impact on groundwater levels. This

could have adverse impacts on these habitat types and a

number of attributes, including habitat area, peat formation,

vegetation composition and physical structure. However,

significant changes to the hydrogeological regime are

unlikely as the works will restore the system to the design

standard only. The drainage maintenance activities are

therefore unlikely to impact significantly on attributes used

to define conservation status.

Follow protocols and EPs in OPW (2019) - specifically, EP7

Environemntal Drainage Maintenancxe (EDM) and the

procedures under the Environmental Drainage Procedure EP,

including compliance with the 10-point plan and auditing

processes. Works should follow those as describes in

guidance under EP10 Drainage Maintenance Silt

Management, including but not limited to working upstream,

skipping sections and leaving buffer zones both instream and

along the banks. Machinery Related Procedures should be

followed to include no refuelling within 50m of a

watercourse, use of biodegradable oils, ensure availability

of spill kits and leave natural vegetation buffer strip along

the bank.

See Table 6-1



existing design level, which has been in existence since 1986

No



Table 5-13 Impact Prediction - Galway Bay Complex SAC (000268)

Qualifying

Interests/

Special

Conservation

Interests

Potential Source

of Impact Pathway

Impact on Attribute and Target Prior to Mitigation

/Avoidance Avoidance / Mitigation Measures Residual Impact

Mudflats and

sandflats not

covered by

seawater at

low tide

(1140)

Large shallow

inlets and bays

(1160)

Otter Lutra

lutra (1355)

Release of

suspended solids

Release or

changes in

nutrient

levels/pollutants

Surface

Water

The habitats of mudflats/sandflats and large shallow inlets

and bays, although transitional intertidal habitats are

connected to surface water flows. Drainage maintenance

activities could impact on water quality in these habitats, and

consequently impact on the Otter population they support,

through the release of suspended sediments and nutrients

which could potentially result in increased turbidity and

eutrophication, which could then result in algal blooms. This

could reach these habitat types through surface water

pathways. However, given the large size of the bay and

considerable extent of these habitat types, their resilience to

increased nutrient and sediment loadings is likely to be high

and the habitat area and community distribution is unlikely to

be significantly affected by nutrient or sediment release from

drainage maintenance works.

Follow Environmental Procedures in OPW

(2019)- specifically EP7 10 Steps to

Environmentally Friendly Maintenance, EP32

Mudflats and EP20 Otters.

See Table 6-1

The above measures will control sediment

mobilisation and reduce the risk of pollution

incidents thereby reducing the potential

significance of this source of impact on the

surface water dependent habitats and

species within this SAC

No

Changes in water

levels/ channel

morphology

Surface

Water

Changes in water levels/channel morphology are not

considered likely to have an adverse impact on these habitat

types, and the Otter populations they support, via surface

water pathways as the works will restore the system to the

design standard only. The drainage maintenance activities are

therefore unlikely to impact significantly on habitat area or

community distribution. Furthermore, given the large size of the

bay and the considerable extent of these habitat types there

will be a high level of habitat resilience to any localised

upstream changes in water levels.




Mudflats and EP20 Otters.

See Table 6-1

This will ensure that drainage maintenance

works do not change water levels/channel

morphology beyond the existing design level,

which has been in existence since 1986

No

Otter Lutra

lutra (1355)

Physical

disturbance of

habitats (and loss

of wood

Land and Air

The Otter population for which the SAC is designated will be

sensitive to disturbance from machinery and workforces

conducting drainage maintenance operations. It may also be

vulnerable to physical disturbance arising from drainage


(2019)- specifically EP7 10 Steps to No



Qualifying

Interests/

Special

Conservation

Interests

Potential Source

of Impact Pathway



vegetation cover

Noise and visual

disturbance

maintenance activities through the direct removal of vegetation

within the maintenance access corridor. This could impact on

attributes for which the conservation status of Otter is defined,

including the extent of terrestrial or marine habitat. However,

no works will actually take place within the Galway Bay

Complex SAC and therefore habitats supporting Otter within

this site will be unaffected by physical disturbance.

Environmentally Friendly Maintenance and

EP20 Otters

See Table 6-1

Coastal

lagoons

(1150)

Release of

suspended solids

Release or

changes in

nutrient levels

Groundwater

Coastal lagoon habitats are dependent on specific water

quality, including specific salinity regimes and Cholorophyll a

levels and dissolved inorganic nitrogen (NPWS, 2013h).

Drainage maintenance activities could impact on water quality

in these habitat types through the release of suspended

sediments and nutrients which could potentially result in

increased turbidity and eutrophication, which could then result

in algal blooms, through aquifer recharge. This could then

impact on typical plant or animal species present and prevent

achievement of the targets associated with these attributes.


(2019) EP7 10 Steps to Environmentally

Friendly Maintenance

See Table 6-1





groundwater dependent habitats within this

SAC

No

Changes in water

levels/ channel

morphology

Groundwater

Fluctuations in water depth are a natural feature of lagoon

habitats, however, if water levels fluctuate beyond their

natural range due to issues such as drainage (e.g. silt and

vegetation management and aquatic vegetation cutting, or

other activities such as gravel shoal removal), the condition of

habitats can deteriorate. This can occur through the deepening

and widening of channels which could impact on groundwater

levels. As most of the lagoons in the Galway Bay Complex are

shallow, even small changes in water depth can cause a

significant loss in habitat area (NPWS, 2013x). However,

significant changes to the hydrogeological regime are unlikely

as the works will restore the system to the design standard only.



Environmentally Friendly Maintenance.

See Table 6-1




which has been in existence since 1986.

No



Qualifying

Interests/

Special

Conservation

Interests

Potential Source

of Impact Pathway



The drainage maintenance activities are therefore unlikely to

impact significantly on attributes used to define conservation

status.



Table 5-14 Impact Prediction - Greaghans Turlough SAC (000503)

Qualifying

Interests/

Special

Conservation

Interests

Potential

Source of

Impact


Impact

Turloughs

(3180)

Release of

suspended

solids

Release or

changes in

nutrient

levels

Groundwater

Turloughs, being groundwater fed, are typically associated with high

water quality, with naturally low dissolved nutrients, clear water and low

algal growth (NPWS, 2013w). Kilroy et al (2008) also identifies that

turloughs are highly sensitive to changes in groundwater chemistry and

nutrient concentration. Drainage maintenance activities could impact on

water quality in the turlough through the release of suspended sediments

and nutrients which could potentially result in increased turbidity and

eutrophication, which could then result in algal blooms, through aquifer

recharge. This could then impact on vegetation structure and composition

and prevent achievement of the targets associated with these attributes.


specifically EP7 10 Steps to Environmentally

Friendly Maintenance, EP9 Trees and Vegetation


Management (specifically Point 2 where possible)

and EP17 Water Pollution.

See Table 6-1


mobilisation and reduce the risk of pollution incidents

thereby reducing the potential significance of this

source of impact on the groundwater dependent

habitat within this SAC

No

Changes in

water

levels/

channel

morphology

Groundwater

Hydrology is the key driver of turlough ecology, with different turlough

communities, assemblages and species affected by various hydrological

attributes (NPWS, 2013w). Drainage maintenance activities, such as silt

and vegetation management and aquatic vegetation cutting, or other

activities such as gravel shoal removal, can result in the deepening and

widening of channels which could impact on groundwater levels. As

turloughs flood primarily as a result of rising groundwater, any change in

the levels of this could have adverse impacts of turlough ecology and a

number of attributes, including habitat area, habitat distribution,

vegetation composition and structure and typical species. However,

significant changes to the hydrogeological regime are unlikely as the

works will restore the system to the design standard only. The drainage








and EP17 Water Pollution

See Table 6-1


not change water levels/channel morphology

beyond the existing design level, which has been in

existence since 1986

No



Table 5-15 Impact Prediction Kilglassan/ Caheravoostia Turlough Complex SAC (000504)

Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

Turloughs (3180)

Release of

suspended

solids

Release or

changes in

nutrient levels

Groundwater

Turloughs, being groundwater fed, are typically associated with high

water quality, with naturally low dissolved nutrients, clear water and

low algal growth (NPWS, 2013w). Kilroy et al (2008) also identifies

that turloughs are highly sensitive to changes in groundwater

chemistry and nutrient concentration. Drainage maintenance

activities could impact on water quality in the turlough through the

release of suspended sediments and nutrients which could potentially

result in increased turbidity and eutrophication, which could then

result in algal blooms. This could reach the turlough habitat through

surface water pathways, or through aquifer recharge via

groundwater pathways. This could then impact on vegetation

structure and composition and prevent achievement of the targets

associated with these attributes.

Follow Environmental Procedures in OPW (2019)- specifically

EP7 10 Steps to Environmentally Friendly Maintenance, EP9

Trees and Vegetation Management, EP10 Drainage

Maintenance Silt Management (specifically Point 2 where

possible) and EP17 Water Pollution.

See Table 6-1

The above measures will control sediment mobilisation and

reduce the risk of pollution incidents thereby reducing the

potential significance of this source of impact on the surface

and groundwater dependent habitat within this SAC

No

Changes in

water levels/

channel

morphology

Groundwater

Hydrology is the key driver of turlough ecology, with different

turlough communities, assemblages and species affected by various

hydrological attributes (NPWS, 2013w). Drainage maintenance

activities, such as silt and vegetation management and aquatic

vegetation cutting, or other activities such as gravel shoal removal,

can result in the deepening and widening of channels which could

impact on groundwater levels. As turloughs flood primarily as a

result of rising groundwater, any change in the levels of this could

have adverse impacts on turlough ecology and a number of

attributes, including habitat area, habitat distribution, vegetation

composition and structure and typical species. However, significant

changes to the hydrological and hydrogeological regime are






Maintenance, EP9 Trees and Vegetation Management, EP10

Drainage Maintenance Silt Management (specifically Point 2

where possible) and EP17 Water Pollution

See Table 6-1


change water levels/channel morphology beyond the existing

design level, which has been in existence since 1986.

No



Table 5-16 Impact Prediction Levally Lough SAC (000295)

Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

Turloughs (3180)

Release of

suspended

solids

Release or

changes in

nutrient levels

Groundwater

Turloughs, being groundwater fed, are typically associated with high water

quality, with naturally low dissolved nutrients, clear water and low algal

growth (NPWS, 2013w). Kilroy et al (2008) also identifies that turloughs are

highly sensitive to changes in groundwater chemistry and nutrient

concentration. Drainage maintenance activities could impact on water

quality in the turlough through the release of suspended sediments and

nutrients which could potentially result in increased turbidity and

eutrophication, which could then result in algal blooms. This could reach the

turlough habitat through surface water pathways, or through aquifer

recharge via groundwater pathways. This could then impact on vegetation

structure and composition and prevent achievement of the targets associated

with these attributes.







See Table 6-1.


mobilisation and reduce the risk of pollution incidents

thereby reducing the potential significance of this

source of impact on the surface and groundwater

dependent habitat within this SAC

No

Changes in

water levels/

channel

morphology

Groundwater

Hydrology is the key driver of turlough ecology, with different turlough

communities, assemblages and species affected by various hydrological

attributes (NPWS, 2013w). Drainage maintenance activities, such as silt and

vegetation management and aquatic vegetation cutting, or other activities

such as gravel shoal removal, can result in the deepening and widening of

channels which could impact on groundwater levels. As turloughs flood

primarily as a result of rising groundwater, any change in the levels of this

could have adverse impacts on turlough ecology and a number of attributes,

including habitat area, habitat distribution, vegetation composition and

structure and typical species. However, significant changes to the

hydrological and hydrogeological regime are unlikely as the works will

restore the system to the design standard only. The drainage maintenance

activities are therefore unlikely to impact significantly on attributes used to

define conservation status.






and EP17 Water Pollution See Table 6-1


not change water levels/channel morphology

beyond the existing design level, which has been in


No



Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

Physical

disturbance of

habitats (and

loss of wood

vegetation

cover

Land and Air

The turlough habitat type for which this SAC is designated is likely to be

vulnerable to physical disturbance arising from drainage maintenance

activities through the direct removal of vegetation within the maintenance

access corridor. This could impact on a range of attributes including habitat

area and vegetation composition. However, given that maintenance

activities are conducted along watercourses that have been periodically

subject to such activities, and that the bank of operation remains consistent,

there will be a working corridor along the channels which has been subject

to periodic physical disturbance and is consequently unlikely to represent

high quality habitat of these Annex I types.







See Table 6-1

No



Table 5-17 Impact Prediction Lisnageeragh Bog and Ballinastack Turlough SAC (000296)

Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

Turloughs (3180)

Active raised bogs

(7110)

Degraded raised

bogs still capable

of natural

regeneration

(7120)

Depressions on

peat substrates of

the Rhynchosporion

(7150)

Changes in

water

levels/

channel

morphology

Groundwater



Drainage maintenance activities, such as silt and vegetation management and aquatic

vegetation cutting, or other activities such as gravel shoal removal, can result in the

deepening and widening of channels which could impact on groundwater levels. As

turloughs flood primarily as a result of rising groundwater, any change in the levels of

this could have adverse impacts on turlough ecology and a number of attributes,

including habitat area, habitat distribution, vegetation composition and structure and

typical species. However, significant changes to the hydrological and hydrogeological

regime are unlikely as the works will restore the system to the design standard only.

The drainage maintenance activities are therefore unlikely to impact significantly on





Trees and Vegetation Management, EP10

Drainage Maintenance Silt Management

(specifically Point 2 where possible) and

EP17 Water Pollution. See Table 6-1



morphology beyond the existing design

level, which has been in existence since

1986

No

Turloughs (3180)

Active raised bogs

(7110)

Degraded raised

bogs still capable

of natural

regeneration

(7120)

Depressions on

peat substrates of

the Rhynchosporion

(7150)

Physical

disturbance

of habitats

(and loss of

wood

vegetation

cover

Land and Air

The degraded raised bog habitat for which this SAC is designated is likely to be


the direct removal of vegetation within the maintenance access corridor. This could

impact on a range of attributes including habitat area and vegetation composition.

Habitats recorded during the walkover survey were dominated by dry grassland

types, scrub and willow woodland; consequently, adverse impacts on this Annex I

habitat type cannot occur via this pathway.







EP17 Water Pollution.

See Table 6-1

No

Release of

suspended

solids

Release or

changes in

Groundwater

Turloughs and raised bogs (both active and degraded) are groundwater fed and

dependent on specific water quality attributes. For example, turloughs are typically

associated with high water quality, with naturally low dissolved nutrients, clear water

and low algal growth (NPWS, 2013w). However, raised bog habitats have a

lowmoderate sensitivity to changes in groundwater level. Kilroy et al (2008) also

identifies that turloughs are highly sensitive to changes in groundwater chemistry and

nutrient concentration. Drainage maintenance activities could impact on water quality






No



Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

nutrient

levels

in the turlough habitat through the release of suspended sediments and nutrients which

could potentially result in increased turbidity and eutrophication, which could then result

in algal blooms. This could reach these GWD habitats through aquifer recharge via

groundwater pathways. This could then impact on vegetation structure and composition

and prevent achievement of the targets associated with these attributes. Changes in

groundwater quality are not considered to have a significant impact on the raised bog

habitat types as they have a low sensitivity to changes in groundwater nutrient

concentration and chemistry (Kilroy et al, 2008); consequently, any changes are likely

to have minimal impacts on these more resilient habitats.


EP17 Water Pollution.

See Table 6-1





groundwater dependent habitats within this

SAC



Table 5-18 Impact Prediction - Lough Carra/ Mask Complex SAC (001774)



Interests

Potential

Source of

Impact


Impact


Oligotrophic waters

containing very few



(3110)

Hard oligo-mesotrophic

waters with benthic


(3140)




davallianae (7210)


Alluvial forests with Alnus




albae) (91E0)

Release

of

suspende

d solids

Release

or

changes

in nutrient

levels

Surface

Water

Ground

water

Lake, fen and alluvial forest habitats are dependent on specific water quality and

nutrient requirements. For example, calcareous fens with Cladium mariscus require

appropriate water quality to support the natural structure and functioning of the

habitat, generally receiving natural levels of nutrients (i.e. iron, magnesium and

calcium) from water sources, with generally low nitrogen and phosphorous which can

be limiting (NPWS, 2013h). Similarly, alluvial forest habitats are also dependent on

groundwaters, with connectivity to surface waters, and have therefore developed in

response to specific water quality parameters and the lake habitats have a very

specific trophic status (i.e. oligotrophic/ mesotrophic). Furthermore, Otter populations

that wetland habitats support could be impacted upon if declines in water quality

impact upon the food resource of this species. Drainage maintenance activities could

impact on water quality in these habitats, and consequently impact on the Otter

population they support, through the release of suspended sediments and nutrients

which could potentially result in increased turbidity and eutrophication, which could

then result in algal blooms. This could reach these habitat types through surface water

pathways, and then impact on a number of attributes such as vegetation composition

or substratum composition.



Environmentally Friendly Maintenance,

EP9 Trees and Vegetation Management,

EP10 Drainage Maintenance Silt

Management (specifically Point 2 where

possible), EP17 Water Pollution, EP20

Otter, EP30 Alluvial (Wet woodland) and

EP31 Wetland. See Table 6-1


mobilisation and reduce the risk of

pollution incidents thereby reducing the

potential significance of this source of

impact on the surface water dependent

habitats, and the species they support,

within this SAC

No

Changes

in water

levels/

channel

morpholo

gy

Surface

Water

Maintenance of appropriate hydrological regimes is a key attribute of these lake, fen

and alluvial forest habitats. For example, calcareous fen habitats require natural

groundwater levels, surface water flows and water table levels to maintain this

habitat type, otherwise scrub and trees can invade as conditions become drier (NPWS,

2013h) and alluvial forests are dependent on periodic flooding to maintain their

habitat area along floodplains (NPWS, 2012a). Drainage maintenance activities, such

as silt and vegetation management and aquatic vegetation cutting, or other activities

such as gravel shoal removal, can result in the deepening and widening of channels

which could impact on surface water flows and water table levels. This could have

adverse impacts on these habitats and a number of attributes, including habitat area,

habitat distribution, vegetation composition and structure and typical species.

However, significant changes to the hydrological regime are unlikely as the works will









EP31 Wetland. See Table 6-1



No





Interests

Potential

Source of

Impact


Impact

restore the system to the design standard only. The drainage maintenance activities

are therefore unlikely to impact significantly on attributes used to define conservation

status.



1986


Slender Green Feather

Moss Drepanocladus

vernicosus (1393)

European dry heaths

(4030)




davallianae (7210)


Limestone pavements

(8240)





albae) (91E0)

Physical

disturban

ce of

habitats

(and loss

of wood

vegetatio

n cover

Land and

Air

The heath, fen, alluvial forest and limestone pavement habitats for which the SAC is

designated are likely to be vulnerable to physical disturbance arising from drainage

maintenance activities through the direct removal of vegetation within the maintenance

access corridor. This could impact on a range of attributes including habitat area and

vegetation structure and composition. Physical disturbance of habitats can also

adversely impact on the species within the SAC by removing cover for Otter and

altering the area of habitat suitable for Slender Green Feather Moss. However, given

that maintenance activities are conducted along watercourses that have been


consistent, there will be a working corridor along the channels which has been subject

to periodic physical disturbance and is consequently unlikely to represent high quality

habitat of these Annex I types.









EP31 Wetland in order to minimise the

impact of physical disturbance

See Table 6-1 No

Otter Lutra lutra (1355) Noise

and

Visual

Disturban

ce

Land and

Air

The Otter population for which the SAC is designated will be sensitive to disturbance

from machinery and workforces conducting drainage maintenance operations. Otters

require lying up areas throughout their territory where they are secure from

disturbance (NPWS, 2013h) and drainage maintenance activities can create

disturbance which could reduce the suitability of terrestrial and freshwater (river/lake)

habitats for this species.



Environmentally Friendly Maintenance

and EP20 Otter See Table 6-1 No





Interests

Potential

Source of

Impact


Impact

Slender Green Feather

Moss Drepanocladus

vernicosus (1393)

Oligotrophic waters

containing very few



(3110)

Hard oligo-mesotrophic

waters with benthic


(3140)




davallianae (7210)






albae) (91E0)

Release

of

suspende

d solids

Release

or

changes

in nutrient

levels

Ground

water

Lake, fen and alluvial forest habitats are dependent on specific water quality and

nutrient requirements. For example, calcareous fens with Cladium mariscus require

appropriate water quality to support the natural structure and functioning of the

habitat, generally receiving natural levels of nutrients (i.e. iron, magnesium and

calcium) from water sources, with generally low nitrogen and phosphorous which can

be limiting (NPWS,2013h). Similarly, alluvial forest habitats are also dependent on

groundwaters, with connectivity to surface waters, and have therefore developed in

response to specific water quality parameters and the lake habitats have a very

specific trophic status (i.e. oligotrophic/mesotrophic). Furthermore, the Slender Green

Feather Moss population these habitats support is also dependent on good water

quality. Drainage maintenance activities could impact on water quality in these

habitats, and consequently impact on the moss population they support, through the

release of suspended sediments and nutrients which could potentially result in

increased turbidity and eutrophication, which could then result in algal blooms. This

could reach these GWD habitats through aquifer recharge via groundwater

pathways. This could then impact on vegetation structure and composition and prevent

achievement of the targets associated with these attributes.








Alluvial (Wet woodland) and EP31

Wetland. See Table 6-1


mobilisation and reduce the risk of

pollution incidents thereby reducing the

potential significance of this source of

impact on

the groundwater dependent habitats, and

the moss species they support, within this

SAC

No

Changes

in water

levels/

channel

morpholo

gy

Ground

water

Maintenance of appropriate hydrological regimes is a key attribute of these lake, fen

and alluvial forest habitats. For example, calcareous fen habitats require natural

groundwater levels, surface water flows and water table levels to maintain this

habitat type, otherwise scrub and trees can invade as conditions become drier (NPWS,

2013h) and alluvial forests are dependent on periodic flooding to maintain their

habitat area along floodplains (NPWS, 2012a). Drainage maintenance activities, such

as silt and vegetation management and aquatic vegetation cutting, or other activities

such as gravel shoal removal, can result in the deepening and widening of channels

which could impact on groundwater levels. This could have adverse impacts on these

habitats and a number of attributes, including habitat area, habitat distribution,

vegetation composition and structure and typical species. However, significant








Alluvial (Wet woodland) and EP31

Wetland. See Table 6-1




No





Interests

Potential

Source of

Impact


Impact

changes to the hydrogeological regime are unlikely as the works will restore the

system to the design standard only. The drainage maintenance




1986



Table 5-19 Impact Prediction - Lough Corrib SAC (000297)



Potential

Source of

Impact


Impact

Freshwater pearl mussel


(1029)

White-clawed crayfish

Austropotamobius pallipes (1092)

Sea lamprey Petromyzon marinus

(1095)

Brook lamprey Lampetra planeri

(1096)



Slender naiad Najas flexilis

(1833)

Oligotrophic waters containing

very few minerals of sandy

plains (Littorelletalia uniflorae)

(3110)

Hard oligo-mesotrophic waters


spp. (3140)





vegetation (3260)

Release of

suspended

solids

Release or

changes in

nutrient levels

Surface

Water

The lake, riverine, fen, spring and woodland habitats for which this

SAC is designated are dependent on specific water quality and

nutrient requirements. For example, watercourses with floating river

vegetation need the concentration of nutrients to be sufficiently low

to prevent changes in species composition or habitat condition.

Substratum also needs to be dominated by appropriate particle

sizes (NPWS, 2017a), and calcareous fens with Cladium mariscus

require appropriate water quality to support the natural structure

and functioning of the habitat, generally receiving natural levels of

nutrients (i.e. iron, magnesium and calcium) from water sources, with

generally low nitrogen and phosphorous which can be limiting

(NPWS,2013h). The other screened in surface water dependent

habitat types within the SAC have also developed in response to

specific water quality parameters and the lake habitats have a very

specific trophic status (i.e. oligotrophic/ mesotrophic). Furthermore,

the species for which the SAC has been developed could also be

adversely impacted upon by declines in water quality. For example,

the favourable conservation condition of Salmon is measured by

water quality attributes. In particular, Freshwater Pearl Mussel

require high water quality with very low nutrient concentrations and

stable cobble and gravel substrate with very little fine material or

artificially elevated levels of fine sediment (NPWS, 2017a).

Drainage maintenance activities could impact on water quality in

these habitats, and consequently impact on the species they support,

through the release of suspended sediments and nutrients which

could potentially result in increased turbidity and eutrophication,

which could then result in algal blooms. This could reach these habitat

types through surface water pathways, and then impact on a number

of attributes such as vegetation composition or substratum

composition.





(specifically Point 2 where possible), EP17

Water Pollution, EP19 Salmonid, EP20 Otter,

EP21 Lamprey, EP22 Crayfish, EP28 Fresh

Water Pearl Mussel, EP33 Floating River

Vegetation Habitat, EP30 Alluvial (Wet

woodland) and EP31 Wetland.

To further protect Freshwater Pearl Mussel

populations on the Owenriff River and its

tributaries (i.e. CH9 Sect 1,

CH9 Sect 2, CH9 Sect 3, CH9/1, CH9/1/1,

CH9/2, F.28, F.28/1 F.60, F.102, F.129, F.145):

-The release of suspended solids will be

minimised during works.

-Place appropriate silt containment measures at

the downstream extent of works (i.e. straw

bales).

-Work from most upstream section to

downstream to further minimise silt mobilisation.

See Table 6-1





No





Potential

Source of

Impact


Impact

Calcareous fens with Cladium


Caricion davallianae (7210)

Petrifying springs with tufa

formation (Cratoneurion) (7220)


Bog woodland (91D0)

surface water dependent habitats and species

within this SAC

Changes in

water levels/

channel

morphology

Surface

Water

Maintenance of appropriate hydrological regimes is a key attribute

of the lake, riverine, fen, spring and woodland habitats for which

this SAC is designated. For example, calcareous fen habitats require

natural groundwater levels, surface water flows and water table

levels to maintain this habitat type, otherwise scrub and trees can

invade as conditions become drier (NPWS, 2013h) and it is an

important attribute for the riverine, lake woodland and spring

habitats within the SAC. The aquatic species for which the SAC is

designated are also dependent on specific hydrological regimes, for

example, Freshwater Pearl Mussel require flow variability and an

appropriate hydrological regime to ensure that high flows wash out

fine sediments from the substratum and that low flows do not

exacerbate deposition of fine sediment and cause stress to mussels

through exposure, water temperature, food availability or impact

on the reproductive cycle (NPWS, 2017a). Drainage maintenance

activities, such as silt and vegetation management and aquatic

vegetation cutting, or other activities such as gravel shoal removal,

can result in the deepening and widening of channels which could

impact on surface water flows and water table levels. This could

have adverse impacts on these habitats, and the species they

support, and a number of attributes, including habitat area, habitat

distribution, vegetation composition and structure and typical

species. However, significant changes to the hydrological regime are










EP21 Lamprey, EP22 Crayfish, EP28 Fresh

Water Pearl Mussel, EP33 Floating River


woodland) and EP31 Wetland

See Table 6-1




which has been in existence since 1986.

No





Potential

Source of

Impact


Impact



(1029)




(1095)


(1096)


Lesser horseshoe bat Rhinolophus

hipposideros (1303)


Slender Green Feather Moss

Drepanocladus vernicosus (1393)





(3260)

Semi-natural dry grasslands and



(*important orchid sites) (6210)

Physical

disturbance

of habitats

(and loss of

wood

vegetation

cover

Land and

Air

The terrestrial and wetland habitats for which the SAC is designated

are likely to be vulnerable to physical disturbance arising from

drainage maintenance activities through the direct removal of

vegetation within the maintenance access corridor. This could impact

on a range of attributes including habitat area and vegetation

structure and composition. Physical disturbance of habitats can also

adversely impact on the species within the SAC, for example by

removing cover for Otter, altering the area of habitat suitable for

Slender Green Feather Moss and by damaging redds used by

Salmon for spawning or lamprey spawning areas. However, given

that maintenance activities are conducted along watercourses that

have been periodically subject to such activities, and that the bank

of operation remains consistent, there will be a working corridor

along the channels which has been subject to periodic physical

disturbance and is consequently unlikely to represent high quality


A reduction in habitat quality and physical alterations can also be

caused by the introduction of non-native invasive species or the

spread of Crayfish plague. Crayfish plague has been confirmed to

occur in the Clare River.







EP21 Lamprey, EP22 Crayfish, EP26 Bats, EP28

Fresh Water Pearl Mussel, EP33 Floating River


woodland) and EP31 Wetland

See Table 6-1

All equipment and machinery that enters the

water will be considered to be contaminated

with crayfish plague. Decontamination will

require the adherence to stringent biosecurity

measures. EP18B

No





Potential

Source of

Impact


Impact

Molinia meadows on calcareous,


(Molinion caeruleae) (6410)

Active raised bogs (7110)

Degraded raised bogs still

capable of natural regeneration

(7120)

Depressions on peat substrates of

the Rhynchosporion (7150)







Limestone pavements (8240)

Bog woodland (91D0)



(1029)




(1095)

Noise and

Visual

Disturbance

Land and

Air

The Otter, lamprey, bat, Salmon and Freshwater Pearl Mussel

populations for which the SAC is designated will be sensitive to

disturbance from machinery and workforces conducting drainage

maintenance operations. For example, Otters require lying up areas

throughout their territory where they are secure from disturbance

(NPWS, 2013h) and drainage maintenance activities can create

disturbance which could reduce the suitability of terrestrial and

freshwater (river/lake) habitats for this species.




Salmonid, EP20 Otter, EP21 Lamprey, EP22

Crayfish, EP26 Bats and EP28 Fresh Water

Pearl Mussel

See Table 6-1

No





Potential

Source of

Impact


Impact


(1096)



hipposideros (1303)





hipposideros (1303)

Oligotrophic waters containing

very few minerals of sandy

plains (Littorelletalia uniflorae)

(3110)

Hard oligo-mesotrophic waters


spp. (3140)





(3260)

Molinia meadows on calcareous,


(Molinion caeruleae) (6410)

Release of

suspended

solids

Release or

changes in

nutrient levels

Groundw

ater

The lake, riverine, Molinia meadow, raised bog, fen, spring and

woodland habitats for which this SAC is designated are dependent

on specific water quality and nutrient requirements. For example,

calcareous fens with Cladium mariscus require appropriate water

quality to support the natural structure and functioning of the habitat,

generally receiving natural levels of nutrients (i.e. iron, magnesium

and calcium) from water sources, with generally low nitrogen and

phosphorous which can be limiting (NPWS,2013h) and watercourses

with floating river vegetation need the concentration of nutrients to

be sufficiently low to prevent changes in species composition or

habitat condition. Substratum also needs to be dominated by

appropriate particle sizes (NPWS, 2012a). Furthermore, a number

of the species the habitats within the SAC supports are dependent

on good water quality (e.g. White-clawed Crayfish). Drainage

maintenance activities could impact on water quality in these

habitats, and consequently impact on the species they support,

through the release of suspended sediments and nutrients which

could potentially result in increased turbidity and eutrophication,

which could then result in algal blooms. This could reach the GWD

habitats through aquifer recharge via groundwater pathways. This

could then impact on vegetation structure and composition and

prevent achievement of the targets associated with these attributes.






Water Pollution, EP22 Crayfish, EP26 Bats,

EP30 Alluvial (Wet woodland) and EP31

Wetland

See Table 6-1





groundwater dependent habitats and species

within this SAC

No





Potential

Source of

Impact


Impact

Active raised bogs (7110)

Degraded raised bogs still

capable of natural regeneration

(7120)

Depressions on peat substrates of

the Rhynchosporion (7150)







Bog woodland (91D0)

Changes in

water levels/

channel

morphology

Ground

water

Maintenance of appropriate hydrological regimes is a key attribute

of these lake, riverine, Molinia meadow, raised bog, fen, spring and

woodland habitats. For example, calcareous fen habitats require

natural groundwater levels, surface water flows and water table

levels to maintain this habitat type, otherwise scrub and trees can

invade as conditions become drier (NPWS, 2013h). Drainage

maintenance activities, such as silt and vegetation management and

aquatic vegetation cutting, or other activities such as gravel shoal

removal, can result in the deepening and widening of channels which

could impact on groundwater levels. This could have adverse impacts

on these habitats and a number of attributes, including habitat area,

habitat distribution, vegetation composition and structure and typical

species. However, significant changes to the hydrogeological regime

are unlikely as the works will restore the system to the design

standard only. The drainage maintenance activities are therefore

unlikely to impact significantly on attributes used to define







Water Pollution, EP22 Crayfish, EP26 Bats,

EP30 Alluvial (Wet woodland) and EP31

Wetland

See Table 6-1







Table 5-20 Impact Prediction - Lough Lurgeen Bog/ Glenamaddy Turlough SAC (000301)

Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

Turloughs (3180)

Release of

suspended

solids

Release or

changes in

nutrient

levels

Ground

Water

Turloughs, being groundwater fed, are typically associated with high water quality,

with naturally low dissolved nutrients, clear water and low algal growth (NPWS,

2013w). Drainage maintenance activities could impact on water quality in the turlough

through the release of suspended sediments and nutrients which could potentially result

in increased turbidity and eutrophication, which could then result in algal blooms. This

could reach the turlough habitat through surface water pathways. This could then impact

on vegetation structure and composition and prevent achievement of the targets

associated with these attributes.



Environmentally Friendly Maintenance, EP9 Trees

and Vegetation Management, EP10 Drainage

Maintenance Silt Management (specifically Point

2 where possible) and EP17 Water Pollution.

See Table 6-1




significance of this source of impact on the surface

water dependent habitat within this SAC

No

Changes in

water

levels/

channel

morphology

Surface

Water





deepening and widening of channels which could impact on groundwater levels. Whilst

turloughs are GWD habitats, they do have connectivity to surface waters, therefore

changes in water levels and channel morphology as a result of drainage maintenance

activities on nearby watercourses could also result in adverse impacts via surface water

pathways. However, significant changes to the hydrological regime are unlikely as the

works will restore the system to the design standard only. The drainage maintenance









See Table 6-1

This will ensure that drainage maintenance works

do not change water levels/channel morphology

beyond the existing design level, which has been

in existence since 1986

No

Turloughs (3180)

Active raised bogs

(7110)

Physical

disturbance

of habitats

(and loss of

Land

and Air

The turlough and raised bog habitats for which this SAC is designated is likely to be


the direct removal of vegetation within the maintenance access corridor. This could

impact on a range of attributes including habitat area and vegetation composition.


specifically EP7 10 Steps to Environmentally No



Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

Degraded raised

bogs still capable

of natural

regeneration

(7120)

Depressions on

peat substrates of

the Rhynchosporion

(7150)

wood

vegetation

cover

However, given that maintenance activities are conducted along watercourses that

have been periodically subject to such activities, and that the bank of operation remains

consistent, there will be a working corridor along the channels which has been subject

to periodic physical disturbance and is consequently unlikely to represent high quality


Friendly Maintenance and EP9 Trees and

Vegetation Management

See Table 6-1

Turloughs (3180)

Active raised bogs

(7110)

Degraded raised

bogs still capable

of natural

regeneration

(7120)

Release of

suspended

solids

Release or

changes in

nutrient

levels

Ground

water

Turloughs and raised bogs (both active and degraded) are groundwater fed and

dependent on specific water quality attributes. For example, turloughs are typically

associated with high water quality, with naturally low dissolved nutrients, clear water

and low algal growth (NPWS, 2013w). Kilroy et al (2008) also identifies that turloughs

are highly sensitive to changes in groundwater chemistry and nutrient concentration.

Drainage maintenance activities could impact on water quality in the turlough habitats

through the release of suspended sediments and nutrients which could potentially result

in increased turbidity and eutrophication, which could then result in algal blooms. This

could reach these GWD habitats through aquifer recharge via groundwater pathways.

This could then impact on vegetation structure and composition and prevent

achievement of the targets associated with these attributes. Changes in groundwater

quality are not considered to have a significant impact on the raised bog habitat types

as they have a low sensitivity to changes in groundwater nutrient concentration and

chemistry (Kilroy et al, 2008); consequently, any changes are likely to have minimal

impacts on these more resilient habitats.



Environmentally Friendly Maintenance, EP9 Trees

and Vegetation Management, EP10 Drainage


2 where possible) and EP17 Water Pollution .

See Table 6-1





groundwater dependent habitats within this SAC

No

Changes in

water

levels/

channel

morphology

Ground

water

The maintenance of an appropriate hydrological regime is critical to the favourable

conservation condition of turlough and raised bog habitats. However, raised bog

habitats have a lowmoderate sensitivity to changes in groundwater level, whereas

turloughs are slightly more sensitive (Kilroy et al, 2008). Drainage maintenance

activities, such as silt and vegetation management and aquatic vegetation cutting, or




Management, EP10 Drainage Maintenance Silt No



Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

other activities such as gravel shoal removal, can result in the deepening and widening

of channels which could impact on groundwater levels. This could have adverse impacts

on a number of attributes, including habitat area, habitat distribution, vegetation

composition and structure and typical species. However, significant changes to the

hydrogeological regime are unlikely as the works will restore the system to the design

standard only. The drainage maintenance activities are therefore unlikely to impact

significantly on attributes used to define conservation status.



See Table 6-1







Table 5-21.Impact Prediction - Maumturk Mountains SAC (002008)

Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

Salmon Salmo salar

(1106)

Release of

suspended

solids

Release or

changes in

nutrient

levels/pollut

ants

Surface

Water

Salmon require good water quality (at least Q4 in all sites sampled by the

Environmental Protection Agency) (NPWS, 2012a). Drainage maintenance

activities could impact on water quality in watercourses within the SAC

containing Salmon through the release of suspended sediments and nutrients

which could potentially result in increased turbidity and eutrophication, which

could then result in algal blooms which could prevent the achievement of water

quality targets.

Follow protocols and OPW Environmental Procedures

(EP) (OPW 2019) - Particularly EP10 Drainage

Maintenance Silt Management Procedure and EP19

Salmonid.

See Table 6-1




impact on the surface water dependent species within

this SAC

No

Changes in

water

levels/

channel

morphology

Surface

Water

Salmon require specific hydrological regimes to support Salmon populations.

Drainage maintenance activities, such as silt and vegetation management and

aquatic vegetation cutting, or other activities such as gravel shoal removal, can

result in the deepening and widening of channels which could impact on flows in

scheme watercourses. However, significant changes to the hydrological regime

are unlikely as the works will restore the system to the design standard only. The

drainage maintenance activities are therefore unlikely to impact significantly on





Salmonid.

See Table 6-1




since 1986

No

Physical

disturbance

of habitats

(and loss of

wood

vegetation

cover

Land and

Air

The riverine habitats that support Salmon populations are likely to be vulnerable

to physical disturbance arising from drainage maintenance activities through the

direct removal of in-channel habitats, including redds. This could impact on a

range of attributes including numbers of adult spawning fish. However, given

that maintenance activities are conducted along watercourses that have been


consistent, there will generally be a working corridor along the channels which

has been subject to periodic physical disturbance. The habitats supporting




Salmonid.

Specific procedures relevant to salmonids include

ensuring on-going consultation with IFI, timing of

No



Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

Salmon populations are subject to regular periods of maintenance and there

will be a period of habitat recovery upon completion of an activity within which

species will re-colonise areas they have potentially been displaced from.

instream works from July to September and protect or

enhance river enhancement works.

See Table 6-1

Noise and

Visual

Disturbance

Land and

Air

Salmon will be sensitive to disturbance from machinery and workforces

conducting drainage maintenance operations, particularly in-channel works.

This could impact on the distribution of a species in a particular area. However,

maintenance operations and the associated works are undertaken on a periodic

basis and only generate noise and visual disturbance on a short-term, temporary

basis. Consequently, whilst these species may be displaced from a working area

during the actual period of works, they are unlikely to be permanently

displaced and so no long-term significant impacts are likely on these species.




Salmonid.

Specific procedures relevant to salmonids, according

to EP19, include ensuring on-going consultation with

IFI, timing of instream works from July to September

and protect or enhance river enhancement works.

See Table 6-1

No

Blanket bog

(*active only)

(7130)

Depressions on

peat substrates of

the Rhynchosporion

(7150)

Release of

suspended

solids

Release or

changes in

nutrient

levels

Ground

water

The blanket bog, and hummock/pool associated within them, are groundwater

fed and dependent on specific water quality attributes. Drainage maintenance

activities could impact on water quality through the release of suspended

sediments and nutrients which could potentially result in increased turbidity and

eutrophication, which could then result in algal blooms. This could reach these

GWD habitats through aquifer recharge via groundwater pathways. However,

changes in groundwater quality are not considered to have a significant impact

on the raised bog habitat types as they have a low sensitivity to changes in

groundwater nutrient concentration and chemistry (Kilroy et al, 2008);

consequently, any changes are likely to have minimal impacts on these more

resilient habitats.



Maintenance point 3, EP9 Tree and Vegetation

Management point 4, EP10 Drainage Maintenance

Silt Management (specifically Point 2 where possible)


See Table 6-1




impact on the groundwater dependent habitats within

this SAC

No

Changes in

water

levels/

Ground

water

Drainage maintenance activities, such as silt and vegetation management and

aquatic vegetation cutting, or other activities such as gravel shoal removal, can

result in the deepening and widening of channels which could impact on


specifically EP7 Environmental Drainage Maintenance

(EDM) and 10 Steps to Environmentally Friendly

No



Qualifying

Interests/ Special

Conservation

Interests

Potential

Source of

Impact


Impact

channel

morphology

groundwater levels. However, Kilroy et al (2008) identifies that active blanket

bog habitats have a low sensitivity to changes in groundwater levels and

consequently drainage maintenance activities are not considered to have a

significant impact on these Annex I habitat types via groundwater pathways.

Furthermore, significant changes to the hydrogeological regime are unlikely as

the works will restore the system to the design standard only. The drainage

maintenance activities are therefore unlikely to impact significantly on attributes

used to define conservation status.

Maintenance. Particular attention is to be payed to

procedures 2.1, 2.2, 2.3 and Section 5 of the

Environmental Drainage Maintenance Guidance Notes

- 10 Steps to Environmentally Friendly Maintenance

and also EP9 Tree and Vegetation Management point

4.

See Table 6-1




since 1986



Table 5-22 Mocorha Lough SAC (001536)

Qualifying

Interests/

Special

Conservation

Interests

Potential Source of

Impact Pathway Impact on Attribute and Target Prior to Mitigation / Avoidance Avoidance / Mitigation Measures

Residual

Impact

Calcareous fens

with Cladium

mariscus and

species of the

Caricion

davallianae

(7210)

Changes in water

levels/ channel

morphology

Surface

Water

Fens require high groundwater levels and so are also vulnerable to changes

in water levels, as they may impact upon the hydrological regime. Surface

water flows should be maintained or restored and changes in water levels

can prevent this target from being achieved. Drainage lowers the water table

and wetland surfaces dry out. This reduces the availability of suitable habitat,

alters species diversity and reduces the presence of brown mosses and other

typical vascular plant species. Lower water levels may cause peat to

compress under its own weight, preventing active peat formation where

appropriate. Impact from change in hydrological condition may affect soil

moisture levels thus affecting vegetation type, quality and ability to support

Annex II species



Friendly Maintenance and EP31 Wetlands.

See Table 6-1





No

Release of

suspended solids

Release or change

in nutrient

levels/pollutants

Surface

Water

Fen habitats are influenced by groundwater and surface water connectivity.

Habitats with water connectivity are susceptible to changes in water quality

as a result of the release of suspended solids, introduction of pollutants or

changes to nutrient levels. Changes to water chemistry that may occur, may

not support the natural structure and functioning of the habitats present. Fens

are naturally poor in nitrogen and phosphorous, so increases in levels of these

may alter typical vegetation composition and ability to support Annex II

species



Friendly Maintenance, EP10 Drainage


2 where possible), EP17 Water Pollution and

EP31 Wetlands.

No



Table 5-23 Monivea Bog SAC (002352)

Qualifying

Interests/

Special

Conservation

Interests

Potential

Source of

Impact


Impact

Active raised

bogs (7110)

Degraded raised

bogs still capable

of natural

regeneration

(7120)

Depressions on

peat substrates of

the

Rhynchosporion

(7150)

Physical

disturbance

of habitats

(and loss of

wood

vegetation

cover

Land and Air

The raised bog habitats, and the associated features are likely to be vulnerable to

physical disturbance arising from drainage maintenance activities through the direct

removal of vegetation within the maintenance access corridor. This could impact on

a range of attributes including habitat area and vegetation structure and

composition. However, given that maintenance activities are conducted along

watercourses that have been periodically subject to such activities, and that the bank

of operation remains consistent, there will be a working corridor along the channels

which has been subject to periodic physical disturbance and is consequently unlikely

to represent high quality habitat of these Annex I types.



Friendly Maintenance, EP9 Tree and Vegetation

Management (specifically Procedure Point 4),

EP10 Drainage Maintenance Silt Management

(specifically Procedure Point 2) and EP31

Wetlands.

See Table 6-1

No

Active raised

bogs (7110)

Degraded raised

bogs still capable

of natural

regeneration

(7120)

Release of

suspended

solids

Release or

changes in

nutrient

levels

Groundwater

Raised bogs (both active and degraded) are groundwater fed and dependent on

specific water quality attributes. Drainage maintenance activities could impact on

water quality in raised bog habitats through the release of suspended sediments

and nutrients which could potentially result in increased turbidity and eutrophication,

which could then result in algal blooms. This could reach these GWD habitats through

aquifer recharge via groundwater pathways. This could then impact on vegetation

structure and composition and prevent achievement of the targets associated with

these attributes. However, changes in groundwater quality are not considered to

have a significant impact on the raised bog habitat types as they have a low

sensitivity to changes in groundwater nutrient concentration and chemistry (Kilroy et

al, 2008); consequently, any changes are likely to have minimal impacts on these

more resilient habitats.







Wetlands.

See Table 6-1





groundwater dependent habitats within this SAC

No



Qualifying

Interests/

Special

Conservation

Interests

Potential

Source of

Impact


Impact

Changes in

water

levels/

channel

morphology

Groundwater

Drainage maintenance activities can result in increased river capacity and flow

leading to hydrological impacts on groundwater levels This could have adverse

impacts on these bog habitats and a number of attributes, including habitat area,

habitat distribution and vegetation composition, potentially resulting in an overall

reduction in the ability of the habitat to support Annex II species. Significant changes

to the hydrogeological regime are unlikely as the works will restore the system to

the design standard only. The drainage maintenance activities are therefore unlikely

to impact significantly on attributes used to define conservation status.







Wetlands.



Table 5-24 Ross Lake and Woods SAC (001312)

Qualifying

Interests/

Special

Conservation

Interests

Potential Source of


Residual

Impact

Hard oligo-

mesotrophic

waters with

benthic

vegetation of

Chara spp.

(3140)

Release of suspended

solids

Release or changes in

nutrient

levels/pollutants

Surface

Water

Drainage maintenance activities could impact on water quality in this habitat

type through the release of nutrients and/ or pollution incidents which could

potentially result in reduced water quality and eutrophication. This in turn could

then result in algal blooms, through aquifer recharge, as well as a reduction in

the habitats overall ability to support Annex II species.




Tree and Vegetation Management

(specifically Procedure Point 4), EP10



Wetlands.

See Table 6-1.





surface water dependent habitats and species

within this SAC

No

Changes in water

levels/ channel

morphology

Surface

Water

Drainage maintenance activities can result in the deepening and widening of

channels which could impact on surface water flows. This could have adverse

impacts on this aquatic habitat and a number of attributes, including habitat

area, habitat distribution and vegetation composition, potentially resulting in an

overall reduction in the ability of the habitat to support Annex II species.




Tree and Vegetation Management

(specifically Procedure Point 4), EP10



Wetlands.

See Table 6-1

No



Qualifying

Interests/

Special

Conservation

Interests

Potential Source of


Residual

Impact

Rhinolophus

hipposideros

(Lesser Horseshoe

Bat) (1303)

Noise and visual

disturbance

Physical alterations/

disturbance to habitat

Reduction in area or

quality of habitats

Land and

Air

Bats may be disturbed by noise disturbance when works occur within areas that

are not normally accessed by the public. Potential summer roosts, if encountered

during spring or summer, may include buildings, for example stables,

abandoned cottages and farm buildings, attics of large houses, large chimneys

of ruined buildings, modern boiler houses, sheds and garages. A decline in

condition may occur if these structures are disturbed during spring or summer.

Potential auxiliary roosts, if encountered at any time of the year within or

adjacent to this SAC, may include any of the above-mentioned underground

structures or buildings. Disturbance and the removal of vegetation from the

surrounding habitat may cause a decline in this attributes condition. Extent of

potential foraging habitat may be reduced through removal of vegetation;

however, this will not be more than the design standard and will be along linear

features already present only.


(2019)- specifically EP26 Bats.

Should works occur in this SAC during spring

or summer, potential summer roost structures

including buildings, for example stables,

abandoned cottages and farm buildings,

attics of large houses, large chimneys of

ruined buildings, modern boiler houses, sheds

and garages should be entirely avoided if

encountered. Works should cease entirely in

these locations and the environmental team

should be contacted for further assessment if

works avoidance is not possible.

No



Table 5-25 Impact Prediction Shrule Turlough SAC (000525)

Qualifying

Interests/

Special

Conservation

Interests

Potential

Source of

Impact Pathway Impact on Attribute and Target Prior to Mitigation / Avoidance Avoidance / Mitigation Measures Residual

Impact

Turloughs

(3180)

Release of

suspended

solids

Release or

changes in

nutrient

levels/polluta

nts

Surface

Water

Ground

water

Changes to groundwater water quality and water levels may impact upon groundwater

dependant habitats such as turloughs, which is a priority Annex 1 habitat. These protected

habitats are also susceptible to changes in water quality as a result of the release of

suspended solids, introduction of pollutants or changes to nutrient levels transferred through

groundwater pathways. Changes in water quality can impact on turloughs by changing the

nutrient composition of the soil and changes in vegetation composition, leading to targets

of maintaining/restore the nutrient status appropriate to the soil type and changes in

vegetation zonation characteristic of the site is not being met.





Management

See Table 6-1




significance of this impact on the surface and

groundwater dependent habitat

No

Changes in

water levels/

channel

morphology

Surface

Water

Ground

water




turloughs flood primarily as a result of rising groundwater, any change in the levels of this

could have adverse impacts on turlough ecology and a number of attributes, including

habitat area, habitat distribution, vegetation composition and structure and typical species.

Additionally, whilst turloughs are GWD habitats, they do have connectivity to surface

waters, therefore changes in water levels and channel morphology as a result of drainage

maintenance activities on nearby watercourses could also result in adverse impacts via

surface water pathways. However, significant changes to the hydrological and

hydrogeological regime are unlikely as the works will restore the system to the design

standard only. The drainage maintenance activities are therefore unlikely to impact






Management.

See Table 6-1





No

Physical

disturbance of

habitats (and

loss of wood

Land and

Air

The turlough habitat type for which this SAC is designated is likely to be vulnerable to

physical disturbance arising from drainage maintenance activities through the direct

removal of vegetation within the maintenance access corridor. This could impact on a range

of attributes including habitat area and vegetation composition. However, given that




Vegetation Management (specifically

No



Qualifying

Interests/

Special

Conservation

Interests

Potential

Source of

Impact Pathway Impact on Attribute and Target Prior to Mitigation / Avoidance Avoidance / Mitigation Measures Residual

Impact

vegetation

cover

maintenance activities are conducted along watercourses that have been periodically

subject to such activities, and that the bank of operation remains consistent, there will be a

working corridor along the channels which has been subject to periodic physical disturbance

and is consequently unlikely to represent high quality habitat of these Annex I types.

Procedure Point 4), EP10 Drainage

Maintenance Silt Management (specifically

Procedure Point 2) and EP31 Wetlands.

See Table 6-1



Table 5-26 Impact Prediction Towerhill House SAC (002179)

Qualifying

Interests/

Special

Conservation

Interests

Potential Source

of Impact Pathway Impact on Attribute and Target Prior to Mitigation / Avoidance Avoidance / Mitigation Measures

Residual

Impact

Lesser horseshoe

bat

Rhinolophus

hipposideros

(1303)

Noise and visual

disturbance

Physical

alterations/

disturbance to

habitat

Reduction in

area or quality

of habitats

Land

and Air

Bats may be disturbed by noise disturbance when works occur within areas

that are not normally accessed by the public. Potential winter roosts, if

encountered during winter, may include underground structures such as

souterrains, cellars, tunnels, ice houses and natural caves. A decline in condition

may occur if these structures are disturbed during winter. Potential summer

roosts, if encountered during spring or summer, may include buildings, for

example stables, abandoned cottages and farm buildings, attics of large

houses, large chimneys of ruined buildings, modern boiler houses, sheds and

garages. A decline in condition may occur if these structures are disturbed

during spring or summer. Potential auxiliary roosts, if encountered at any time

of the year within or adjacent to this SAC, may include any of the above-

mentioned underground structures or buildings. Disturbance and the removal

of vegetation from the surrounding habitat may cause a decline in this

attributes condition. Extent of potential foraging habitat may be reduced

through removal of vegetation; however, this will not be more than the design

standard and will be along linear features already present only.


specifically EP26 Bats

Should works occur in this SAC during winter, potential

winter roost structures including underground

structures such as souterrains, cellars, tunnels, ice

houses and natural caves should be entirely avoided

if encountered. Works should cease entirely in these

locations and the environmental team should be

contacted for further assessment if complete

avoidance is not possible. Should works occur in this

SAC during spring or summer, potential summer roost

structures including buildings, for example stables,

abandoned cottages and farm buildings, attics of

large houses, large chimneys of ruined buildings,

modern boiler houses, sheds and garages should be

entirely avoided if encountered. Works should cease

entirely in these locations and the environmental team

should be contacted for further assessment if works

avoidance is not possible.

No



Table 5-27 Impact Prediction Williamstown Turloughs SAC (002296)

Qualifying

Interests/

Special

Conservation

Interests

Potential Source

of Impact Pathway Impact on Attribute and Target Prior to Mitigation / Avoidance Avoidance / Mitigation Measures

Residual

Impact

Turloughs (3180)

Release of

suspended

solids

Release or

changes in

nutrient

levels/pollutants

Surface Water

Ground water

Changes to groundwater water quality and water levels may impact upon

groundwater dependant habitats such as turloughs, which is a priority Annex 1 habitat.

These protected habitats are also susceptible to changes in water quality as a result

of the release of suspended solids, introduction of pollutants or changes to nutrient

levels transferred through groundwater pathways. Changes in water quality can

impact on turloughs by changing the nutrient composition of the soil and changes in

vegetation composition, leading to targets of maintaining/restore the nutrient status

appropriate to the soil type and changes in vegetation zonation characteristic of the

site is not being met.


OPW (2019)- specifically EP7 10 Steps

to Environmentally Friendly

Maintenance and EP10 Drainage

Maintenance Silt Management. See

Table 6-1





this source of impact on the surface and

groundwater dependent habitat within

this SAC

No

Changes in water

levels/ channel

morphology

Surface Water

Ground water




turloughs flood primarily as a result of rising groundwater, any change in the levels of

this could have adverse impacts on turlough ecology and a number of attributes,

including habitat area, habitat distribution, vegetation composition and structure and

typical species. Additionally, whilst turloughs are GWD habitats, they do have

connectivity to surface waters, therefore changes in water levels and channel

morphology as a result of drainage maintenance activities on nearby watercourses

could also result in adverse impacts via surface water pathways. However, significant

changes to the hydrological and hydrogeological regime are unlikely as the works will

restore the system to the design standard only. The drainage maintenance activities

are therefore unlikely to impact significantly on attributes used to define conservation

status.





Maintenance Silt Management

See Table 6-1


maintenance works do not change water

levels/channel morphology beyond the

existing design level, which has been in


No



Table 5-28 Impact Prediction Inner Galway Bay SPA (004031)


Special Conservation Interests

Potential Source of


Residual

Impact

Great Northern Diver Gavia

immer (A003)

Grey Heron Ardea cinerea

(A028)

Light-bellied Brent Goose Branta

bernicla hrota (A046)

Wigeon Anas penelope (A050)

Teal Anas crecca (A052)

Shoveler Anas clypeata (A056)

Red-breasted Merganser Mergus

serrator (A069)

Ringed Plover Charadrius

hiaticula (A137)

Golden Plover Pluvialis apricaria

(A140)

Lapwing Vanellus vanellus (A140)

Dunlin Calidris alpina (A149)

Bar-tailed Godwit Limosa

lapponica (A157)

Curlew Numenius arquata (A160)

Redshank Tringa totanus (A162)

Turnstone Arenaria interpres

(A169)

Black-headed Gull


(A179)

Common Gull Larus Canus (A182)

Wetlands & Waterbirds (A999)

Release of

suspended

solids


nutrient

levels/pollutants

Surface

Water

Waterbird populations and most of the designated species of this SPA

are dependent on a number of habitats with connectivity to surface

waters within the site, including mudflats/sandflats, inlets and bays.

Drainage maintenance activities could impact on these habitats through

the release of nutrients and suspended solids and pollution incidents

which could potentially result in reduced water quality, eutrophication

and increased turbidity which could impact upon the habitats and

potentially the food supply of these birds, potentially affecting the

distribution of species within the estuary and long-term population

trends. However, given the large size of the bay and considerable

extent of these habitat types, their resilience to increased nutrient and

sediment loadings is likely to be high and the habitat area and

community distribution is unlikely to be significantly affected by nutrient

or sediment release from drainage maintenance works.






Table 6-1





this source of impact on the surface

water dependent habitats supporting

the bird species within this SPA

No

Changes in water

levels/channel

morphology

Surface

Water

The birds for which the SPA is designated are dependent on a number

of habitats with connectivity to surface waters within the site, including

mudflats/sandflats, inlets and bays. Drainage maintenance activities,

such as silt and vegetation management can result in the deepening and

widening of channels which could impact on surface water flows and

water table levels. This could then have adverse impacts on those

habitats and distribution of the waterbirds they support. However,

significant changes to the hydrological regime are unlikely as the works

will restore the system to the design standard only. The drainage








Table 6-1


maintenance works do not change

water levels/channel morphology

beyond the existing design level,


No

Curlew Numenius arquata (A160) Physical disturbance

of habitats (and loss

Land

and Air

Only Curlew were identified as being vulnerable to drainage

maintenance activities via land and air pathways. The habitats that


OPW (2019)- specifically EP25 Birds No





Potential Source of


Residual

Impact

of wood vegetation

cover)

Noise and

Visual

Disturbance

support this species are likely to be vulnerable to physical disturbance

arising from drainage maintenance activities, such as vegetation

removal within the maintenance access corridor. However, given that

maintenance activities are conducted along watercourses that have

been periodically subject to such activities, and that the bank of

operation remains consistent, there will be a working corridor along the

channels which has been subject to periodic physical disturbance and

consequently impacts are likely to be minimised. This species will be

sensitive to noise disturbance from machinery and workforces conducting

drainage maintenance operations during the breeding season.

which includes to plan the time of

works to minimise potential

disturbance on over wintering bird

populations within the SPA and the

sightline to wintering birds should be

minimized.

See Table 6-1

Wetland habitats should be identified

on-site prior to works commencing in

the SPA. Works within or adjacent to

wetlands should follow the Wetland

Procedure EP, including, but not limited

to protecting the wetlands hydraulics

and minimising or avoiding

maintenance.

Cormorant Phalacrocorax carbo

(A017)

Light-bellied Brent Goose Branta

bernicla hrota (A046)

Wigeon Anas penelope (A050)

Teal Anas crecca (A052)

Red-breasted Merganser Mergus

serrator (A069)

Lapwing Vanellus vanellus (A142)

Redshank Tringa tetanus (A162)

Wetlands & Waterbirds (A999)

Release of

suspended

solids


nutrient

levels/pollutants

Changes in water

levels/channel

morphology

Ground

water

A number of the birds for which the SPA is designated are dependent

on groundwater dependent habitats within the site (e.g. coastal

lagoons). Impacts that may arise through groundwater pathways and

impact upon the QIs of this SPA are as those described for Surface

water impacts. Drainage maintenance activities could impact on these

habitats through the release of nutrients and suspended solids which

could potentially result in eutrophication and increased turbidity which

could impact upon the habitats and consequently the food supply of

these birds, potentially affecting the distribution of species within the

estuary and long-term population trends. Changes in water

levels/channel morphology are not considered likely to have an adverse

impact on these habitats, and consequently the bird populations they

support, via groundwater pathways as the works will restore the system

to the design standard only.





Maintenance Silt Management

See Table 6-1





this source of impact, including

cumulative and/or in-combination

impacts, on the wetland and

supporting habitats within this SPA,

that may occur through groundwater

pathways.

No



Table 5-29 Impact Prediction - Lough Carra SPA (004051)

Qualifying

Interests/

Special

Conservation

Interests

Potential Source of

Impact Pathway Impact on Attribute and Target Prior to Mitigation / Avoidance Avoidance / Mitigation Measures Residual Impact

Common Gull

Larus canus

Release of

suspended

solids

Release or changes

in nutrient

levels/pollutants

Surface

Water

The Common Gull population for which the SPA is designated are supported by

surface water dependent habitats. Drainage maintenance activities could

impact on these habitats through the release of nutrients and suspended solids

and pollution incidents which could potentially result in reduced water quality,

eutrophication and increased turbidity which could impact upon the habitats and

potentially the food supply of these birds, potentially affecting the distribution

of species within the estuary and long-term population trends. However, given

the large size of the bay and considerable extent of these habitat types, their

resilience to increased nutrient and sediment loadings is likely to be high and

the habitat area and community distribution is unlikely to be significantly

affected by nutrient or sediment release from drainage maintenance works.






Table 6-1





this source of impact on the surface

water dependent habitats supporting

the bird species within this SPA

No

Changes in water

levels/channel

morphology

Surface

Water

The Common Gull population for which the SPA is designated are supported by

surface water dependent habitats. Drainage maintenance activities, such as silt

and vegetation management can result in the deepening and widening of

channels which could impact on surface water flows and water table levels. This

could then have adverse impacts on those habitats and distribution of the

waterbirds they support. However, significant changes to the hydrological

regime are unlikely as the works will restore the system to the design standard

only. The drainage maintenance activities are therefore unlikely to impact




to Environmentally Friendly Maintenance

and EP10 Drainage Maintenance Silt

Management. See Table 6-1. This will

ensure that drainage maintenance works

do not change water levels/channel



1986

No

Physical

disturbance of

habitats (and loss

of wood vegetation

cover)

Land and

Air

Common Gull populations for which the SPA is designated were identified as

being vulnerable to drainage maintenance activities via land and air pathways.

The habitats that support this species are likely to be vulnerable to physical

disturbance arising from drainage maintenance activities, such as vegetation

removal within the maintenance access corridor. However, given that

maintenance activities are conducted along watercourses that have been


OPW (2019)- specifically EP25 Birds

which includes to plan the time of works

to minimise potential disturbance on bird

populations within the SPA and the

sightline to birds should be minimized.

No



Noise and

Visual

Disturbance


consistent, there will be a working corridor along the channels which has been

subject to periodic physical disturbance and consequently impacts are likely to

be minimised. This species will be sensitive to disturbance from machinery and

workforces conducting drainage maintenance operations during the breeding

season.

See Table 6-1



Table 5-30 Impact Prediction - Lough Corrib SPA (004042)



Potential Source of

Impact Pathway

Impact on Attribute and Target Prior to Mitigation /


Residual

Impact

Greenland Whitefronted

Goose Anser albifrons

flavirostris (A395)

Gadwall Anas strepera (A051)


Pochard Aythya ferina (A059)

Tufted Duck Aythya fuligula

(A061)

Common Scoter Melanitta nigra

(A065)

Coot Fulica atra (A125)

Black-headed Gull

Chroicocephalus ridibundus (A179)

Common Gull Larus canus (A182)

Common Tern Sterna hirundo

(A193)

Arctic Tern Sterna paradisaea

(A194)

Wetlands and Waterbirds (A999)

Release of

suspended solids

Release or

changes in nutrient

levels

Surface

Water

The bird species for which the SPA is designated are

dependent on a number of habitats with connectivity to

surface waters within the site, including lakes, rivers and fens.

Drainage maintenance activities could impact on these

habitats through the release of nutrients, suspended solids

and pollution incidents which could potentially result in

reduced water quality, eutrophication and increased

turbidity, which could impact upon the wetland habitats and

potentially the food supply (i.e. macroinvertebrates and fish)

of the waterbirds, possibly leading to a decrease in the

distribution of species and the long term population trend

within the SPA.





Management.

See Table 6-1





surface water dependent habitats

supporting the bird species within this SPA

No

Changes in water

levels/channel

morphology

Surface

Water

The birds for which the SPA is designated are dependent on

a number of habitats with connectivity to surface waters

within the site, including lakes, rivers and fens. Drainage

maintenance activities, such as silt and vegetation

management can result in the deepening and widening of

channels which could impact on surface water flows and

water table levels. This could then have adverse impacts on

those habitats and distribution of the waterbirds they

support. However, significant changes to the hydrological

regime are unlikely as the works will restore the system to

the design standard only. The drainage maintenance

activities are therefore unlikely to impact significantly on






Management.

See Table 6-1




level, which has been in existence since 1986

No





Potential Source of

Impact Pathway



Residual

Impact

Greenland Whitefronted Goose

Anser albifrons flavirostris (A395)




Tufted Duck Aythya fuligula (A061)


(A065)

Hen Harrier Circus cyaneus (A082)


Black-headed Gull Chroicocephalus

ridibundus (A179)

Common Gull Larus canus (A182)


(A193)


(A194)

Wetlands and waterbirds (A999)

Physical

disturbance of

habitats (and loss

of wood

vegetation cover

Noise and Visual

Disturbance

Land and

Air

A number of bird species for which the SPA is designated

were identified as being vulnerable to drainage

maintenance activities via land and air pathways. Drainage

maintenance works may result in physical disturbance

impacts on waterbirds through reducing the extent of habitat

(terrestrial, river, or lake) and availability of food resources

which can lead to a decrease in distribution of the

waterbirds. The disturbance can also lead to displacement

of waterbirds during the time the maintenance works take

place. The bird species for which the SPA is designated will

be sensitive to disturbance from machinery and workforces

conducting drainage maintenance operations during the

over-wintering period (November - March). This disturbance

could cause displacement of populations which can require

significant energy expenditure for the birds, which, if

undertaken during the cold winter months when birds are

already stressed by recent migrations and difficulties in

finding food, could have an adverse impact on population

trend and distribution.


(2019)- specifically EP25 Birds which

includes to plan the time of works to minimise

potential disturbance on over wintering bird

populations within the SPA and the sightline

to wintering birds should be minimized.

See Table 6-1

Wetland habitats should be identified on-

site prior to works commencing in the SPA.

Works within or adjacent to wetlands should

follow the EP31 Wetland, including, but not

limited to protecting the wetlands hydraulics

and minimising or avoiding maintenance.

No

Greenland Whitefronted Goose

Anser albifrons flavirostris (A395)



Tufted Duck Aythya fuligula (A061)


Release of

suspended solids

Release or changes

in nutrient

levels/pollutants

Ground

water

A number of the birds for which the SPA is designated are

dependent on groundwater dependent habitats within the

site (e.g. coastal lagoons). Impacts that may arise through

groundwater pathways and impact upon the QIs of this SPA

are as those described for Surface water impacts. Drainage

maintenance activities could impact on these habitats

through the release of nutrients and suspended solids which

could potentially result in eutrophication and increased





Management

See Table 6-1

No





Potential Source of

Impact Pathway



Residual

Impact

Hen Harrier Circus cyaneus (A082)



(A193)


(A194)

Wetlands and waterbirds (A999)

Changes in water

levels/channel

morphology

turbidity which could impact upon the habitats and

consequently the food supply of these birds, potentially

affecting the distribution of species within the estuary and

long-term population trends. Changes in water

levels/channel morphology are not considered likely to have

an adverse impact on these habitats, and consequently the

bird populations they support, via groundwater pathways

as the works will restore the system to the design standard

only.




significance of this source of impact, including

cumulative and/or in-combination impacts, on

the wetland and supporting habitats within

this SPA, that may occur through groundwater

pathways.



Table 5-31 Impact Prediction - Lough Mask SPA (004062)

Qualifying Interests

Potential

Source of

Impact


Impact

Tufted Duck Aythya

fuligula (A061)

Black-headed Gull

Chroicocephalus

ridibundus (A179)

Common Gull Larus canus

(A182)

Lesser Black-backed Gull

Larus fuscus (A183)

Common Tern Sterna

hirundo (A193)



flavirostris (A395)

Wetlands & Waterbirds

(A999)

Release of

suspended

solids

Release or

changes in

nutrient

levels/pollutant

s

Surface

Water

The bird species for which the SPA is designated are dependent on a

number of habitats with connectivity to surface waters within the site,

including lakes and fens. Drainage maintenance activities could impact on

these habitats through the release of nutrients, suspended solids and

pollution incidents which could potentially result in reduced water quality,

eutrophication and increased turbidity, which could impact upon the

wetland habitats and potentially the food supply (i.e. macroinvertebrates

and fish) of the waterbirds, possibly leading to a decrease in the

distribution of species and the long term population trend within the SPA.





Management.

See Table 6-1





surface water dependent habitats

supporting the bird species

No

Changes in

water

levels/channel

morphology

Surface

Water

The birds for which the SPA is designated are dependent on a number of

habitats with connectivity to surface waters within the site, including lakes

and fens. Drainage maintenance activities, such as silt and vegetation

management can result in the deepening and widening of channels which

could impact on surface water flows and water table levels. This could then

have adverse impacts on those habitats and distribution of the waterbirds

they support. However, significant changes to the hydrological regime are

unlikely as the works will restore the system to the design standard only.

The drainage maintenance activities are therefore unlikely to impact






Management.

See Table 6-1





1986

No

Tufted Duck Aythya

fuligula (A061) Physical

disturbance of

habitats (and

loss of wood

Land and

Air

A number of bird species for which the SPA is designated were identified

as being vulnerable to drainage maintenance activities via land and air

pathways. The habitats that support this species are likely to be vulnerable

to physical disturbance arising from drainage maintenance activities, such

as vegetation removal within the maintenance access corridor. However,


(2019)- specifically EP25 Birds which

includes to plan the time of works to

minimise potential disturbance on over

wintering bird populations within the SPA

No



Qualifying Interests

Potential

Source of

Impact


Impact

Black-headed Gull

Chroicocephalus

ridibundus (A179)

Common Gull Larus canus

(A182)

Lesser Black-backed Gull

Larus fuscus (A183)

Common Tern Sterna

hirundo (A193)



flavirostris (A395)


(A999)

vegetation

cover

Noise and

Visual

Disturbance

given that maintenance activities are conducted along watercourses that

have been periodically subject to such activities, and that the bank of

operation remains consistent, there will be a working corridor along the

channels which has been subject to periodic physical disturbance and

consequently impacts are likely to be minimised. A number of bird species

for which the SPA is designated were identified as being vulnerable to

drainage maintenance activities via land and air pathways. These species

will be sensitive to disturbance from machinery and workforces conducting

drainage maintenance operations during the breeding season.

and the sightline to wintering birds should

be minimized. See Table 6-1

Wetland habitats should be identified on-

site prior to works commencing in the SPA.

Works within or adjacent to wetlands

should follow the Wetland Procedure EP,

including, but not limited to protecting the

wetlands hydraulics and minimising or

avoiding maintenance.

Tufted Duck Aythya

fuligula (A061)

Common Tern Sterna

hirundo (A193)



flavirostris (A395)


(A999)

Release of

suspended

solids

Release or

changes in

nutrient levels/

pollutants

Changes in

water levels/

channel

morphology

Ground

water

A number of the birds for which the SPA is designated are dependent on

groundwater dependent habitats within the site (e.g. coastal lagoons).

Impacts that may arise through groundwater pathways and impact upon

the QIs of this SPA are as those described for Surface water impacts.

Drainage maintenance activities could impact on these habitats through

the release of nutrients and suspended solids which could potentially result

in eutrophication and increased turbidity which could impact upon the

habitats and consequently the food supply of these birds, potentially

affecting the distribution of species within the estuary and long-term

population trends. Changes in water levels/channel morphology are not

considered likely to have an adverse impact on these habitats, and

consequently the bird populations they support, via groundwater

pathways as the works will restore the system to the design standard only.





Management. See Table 6-1




significance of this source of impact,

including cumulative and/or in-combination

impacts, on the wetland and supporting

habitats within this SPA, that may occur

through groundwater pathways.

No



6 Avoidance and Mitigation Measures

6.1 Introduction

The Environmental Management Protocols and EPs developed by OPW (2019) are routinely followed by

OPW operational staff undertaking drainage maintenance works and help to provide a baseline level of

environmental protection, with a specific focus on certain species and habitats (i.e. Brook, River and Sea

Lamprey, White-clawed Crayfish, Otter, Freshwater Pearl Mussel, invasive species and Zebra Mussel,

alluvial woodland, wetlands, etc.,). In order to ensure that drainage maintenance works and proposed

associated works do not adversely impact on the European Sites and their respective qualifying interests,

specific mitigation and avoidance measures have been highlighted that should be followed. This NIS

considers the potential impact of normal arterial drainage maintenance works on those watercourses

screened into the assessment.

To ensure that adverse impacts do not arise on European Sites and other protected species as a result of

these areterial drainage maintenance works undertaken during the period 2020-2024, all procedures as

recommended in the OPW's Environmental Guidance document (OPW 2019) are to be followd.

Table 6-1 Specific Mitigation Measures

Potential Impact Specific Avoidance and Mitigation Measures

Release of

suspended solids

/ nutrients /

pollutants

Environmental Drainage Maintenance EP7, EP9-EP13

When removing aquatic vegetation instream, maximise the use of a weed cutting bucket where

possible to minimise the amount of silt being disturbed/suspended into the water column from

the river substrate or bank. All aquatic vegetation or branch cuttings shall be removed from

the channel and the channel bank and placed in an area where they cannot re-enter the water.

In situations where there may be a more significant build-up of silt, debris or nutrients e.g.

during sluice maintenance or when clearing channels adjacent to coniferous woodlands or

agricultural lands, there will be a 20m section of channel unmaintained at the channel outfall

and if this is not naturally present, additional silt mitigation measures will be implemented

including the use of geotextiles, clean washed stone and coarse sand (where suitable), removal

of material and/or other silt filtration techniques. The method used will be on a caseby-case

basis and methods used will be documented and discussed with environment team.

If channels need to be accessed by vehicles over soft/wet ground and there is a risk that

significant areas of soil may be exposed, bog mats or sleepers shall be laid.

Lough Corrib SAC Specifics:

Freshwater Pearl Mussel populations are particularly sensitive to the release of suspended

solids and other pollutants. The following measures will be implemented to further protect

Freshwater Pearl Mussel populations in the Owenriff River and its tributaries in the following

channels; CH9 Sect 1, CH9 Sect 2, CH9 Sect 3, C21, C21/1, CH9/1, CH9/1/1, CH9/2, F.28,

F.60, F.102, F.129, F.145:

- The release of suspended solids will be minimised during works.

- Place appropriate silt containment measures at the downstream extent of works (i.e.

straw bales).

- Work from most upstream section to downstream to further minimise silt mobilisation.

- Strimmers and mini-diggers will be employed when maintaining areas adjacent to

sensitive channels, giving greater operating control

Changes in water

levels/ channel

morphology

Environmental Drainage Maintenance EP7, EP9-EP13, EP31

Works on all channels will be undertaken in accordance with the Scheme's design standard, in

order to prevent any new widening or deepening of a channel, which may give rise to a




change in surface water and groundwater levels in the vicinity (both upstream and

downstream) of the works.

Monivea Bog SAC Specifics:

There are 8 side drainage ditches that drain from the high bog area of Monivea Bog SAC

into C3/8/14, 3 of which originate in an area with Potential Active Raised Bog* (see

Appendix A). In order to mitigate against the excessive drainage of Monivea Bog SAC and

aid in its restoration objectives, these 8 drains will be left in their current condition, including

any current vegetative and/or sediment blockages as well as vegetation lining either side of

these ditches. The retained ditch vegetation will provide continuous vegetative debris overtime,

maintaining and/ or creating blockages; as well as shading which will prevent unwanted

evapotranspiration. This will allow for water to be backed up within the bogland, resulting in

a preferred, slower overall drainage of the Annex I bog habitats. These drains are not

currently maintenaned by the OPW, however, clearence of vegetation may be necessary to

maintain the maintenance access corridor so that works may be conducted along the rest of

the channels' length. The retention of ~10m upstream and downstream of the outfall of the

side drains should be considered.

Physical

disturbance of

habitats (and loss

of wood

vegetation cover)

EP7 Environmental Drainage Maintenance, EP9 Tree and Vegetation Management, EP10

Drainage Maintenance Silt Management, EP20 Otter, EP22 Crayfish, EP25 Birds, EP26 Bats

and EP31 Wetlands

The site layout and activities along the maintenance channels have be designed in such a

manner that physical disturbance of the habitats and the species dependent upon them, inside

the boundaries of the SACs and SPAs is kept to a minimum.

Drainage maintenance works will not encroach on wetland habitats including:

- Turloughs and alkaline fens along channel CH 8/2/1 and CH 8/2/2 in Clyard Kettle-

Holes SAC,

- Turloughs and alkaline fens along channel SG.30/3 in Levally Lough SAC,

- Heath, swamp, maral lake and wet woodland habitats along channels CM7, CM7/1,

CM6, CM5, CM5/1, CM5A, CM5/6, CM5/10 Sect.B, CM5/11, CM5/12, CM5/13,

CM5/14, CM8/4, CM9, CM9/1, CM8, CM8/3 and CM11 in Lough Carra/Mask

Complex,

- Heath, bog and wet woodland habitats along channels CH9 Sect.3, F.129, CH9/2,

F.28/1, CH9 Sect.2, CH9 Sect.1, CH10 Sect.2, CH10/2, Cornamona River, CH4/4,

CH4/4/2, CH4/4/1, CH4 Sect.4, F.391, C22, C23, F.137, C25/1, C25, C25/2,

F.1215C, C32/5, S.G.68/7, S.G.68/4, S.G.68/3, S.G.68/5, C32, C33, F.722,

C32/2, C34/1, C35, C1 Sect.5, C1 Sect.4, C1 Sect.3, F.776, C1 Sect.2, C3 Sect.8,

C3/8/8, C3/8 Sect.9, C3, Sect.10, C3/8/23/3, C3/8 Sect.15, C3/9 Sect.3,

C3/9/8/2, C3/9 Sect.11, C3 Sect.12, C3/9 Sect.14, C3 Sect.26, C3/26/3, C3/26,

C3/35 Sect.8 in Lough Corrib SAC

- Bog and turlough habitat along channels C3/8/14, C3/8 Sect. 13, C3/8 Sect.14,

C3/8/17 in Monivea Bog SAC

- Turlough habitat along channel SM122/2 in Shrule Turlough SAC

Works and access will be restricted to the existing maintenance access corridors along these

channels within these European sites. The site layout and activities will be designed in such a

manner that the sensitive habitats will be excluded from all foot traffic, machinery access and

activity, as well as being exempt from all soil, sediment and vegetation displacement.

Works along the embankments and channels within or directly adjacent to SPA’s will be carried

out manually where possible to minimise disturbance and strictly adhere to EP25 Birds

procedure in sections where dense vegetation and branch trimming will take place.




Tree and Vegetation Maintenance works to be undertaken within this maintenance period

within the Owenriff Freshwater Pearl Mussel catchment specificly along channel CH9 Sect. 1

include the removal of fallen wind damage trees, removal of overhanging branches and

trimming/pruning of laurel. These maintenance activities will strictly implement the following

measures to further protect Freshwater Pearl Mussel;

- Where possible, mature trees within the river corridor near pearl mussels should be

retained to minimise bank erosion

- Removal of fallen trees are to be completed by lifting clear of the channel to

minimise any channel bed disturbance by branches being dragged

- Trees that are at risk of falling into the river shall be removed or partialy removed

by suitably trained and experienced forestry personnel (arborest) at mussel

locations and where necessary and technically fesible be replaced

- Any removal of overhanging brances within or just above the water during periods

of low flow will use a saw or secateurs, overhanging brances should be left intact

unless they pose a health and safety risk

- Works are not to be undertaken during periods of prolonged wet weather

- See also EP28

Noise and

visual disturbance

Works and access will be restricted to the existing maintenance access corridor.

No works shall take place within 500m of any SPA designated for breeding birds during the

nesting bird season (March - September) in particular channel C1 Sect.1 within 500m of the

Inner Galway Bay SPA.

No works shall take place within 100m of any SPA designated for over wintering birds during

the overwintering period November to March.

As per the EP19 Salmonid, no works are to occur instream outside of July - September. This

may be extended following consultation with IFI and if further impacts onSalmo salar (Salmon)

[1106] are possible a project specific NIS may be required.

Spread of non-

native invasive

species

Stringent biosecurity measures will be implemented throughout the works following the OPW's

Invasive Species Procedures (Appendix A. Given the recent outbreaks of crayfish plague

reported on the River Clare, the best practice principles of Check-Clean-Dry guidance of the

NNSS (2017), IFI biosecurity protocols (2010) and Waterways Ireland Marine Notice No.

39/2017 (Appendix A.) shall be followed during these works, to ensure that crayfish plague

and non-native invasive species are not introduced into the proposed working area.

1 Works on bridges and sluices located on the above channels and embankments are also subject to the detailed mitigation/avoidance measures.

6.2 Mitigation for Other Ecological Receptors

The ecological walkover surveys (see Section 4.27) identified a number of other potential ecological

constraints to arterial drainage maintenance works, for which European sites are not designated, which will

be taken into account during maintenance operations. Table 6-2 details proposed mitigation measures to

offset impacts on these identified receptors.



Table 6-2 Specific Mitigation Measures for other Ecological Receptors

Receptor Applicable OPW Channels

/ Embankments

Specific Avoidance and Mitigation Measures1

Salmon

and

Trout

All channels Refuelling will not be undertaken within 50m of a watercourse.

Avoid closed season for Salmonids (OctoberApril) in relation to in-

stream silt and vegetation management on channels with salmonid

spawning habitat. Follow EP19

Where Salmonids are absent, undertake instream removal of silts

and gravels in an upstream direction for lamprey and crayfish.

Follow EP21 & 22 Where Salmonids are present, undertake

instream removal of silts in a downstream direction allowing solids

to settle out naturally and/or become trapped in vegetation.

In relation to structural maintenance activities, spawning gravels

located downstream of the structure will be tossed post completion

of works to remove any silts present.

Lamprey

species

Otter

All channels, in particular:

- C3 Sect. 25 and 45

- C3/8 (several sections)

- C3/8/8

- C3/9 Sect. 5 and 9

C3/9/8

- C3/35 Sect. 5 and 8

- C17

The potential presence of Otter

holts/resting places on

watercourses not surveyed, and

also becoming established on

surveyed watercourses during

the life of this assessment also

needs to be considered

Where signifincat construction works are required within 150m of a

breeding Otter holt, a derogation license will be required from

NPWS.

In relation to maintenance no works will be permitted within 30m of

a potential holt. Follow EP20

Bats All masonry bridges

Where masonry bridges require maintenance, a bat roost potential

assessment will be conducted in advance of works. Where bridges

are identified as being of moderate or above suitability for roosting,

nocturnal activity surveys may then be required.

The bat survey and mitigation measures will be in full accordance

with Bat Mitigation Guidelines for Ireland (Irish Wildlife Manual No.

25). Follow EP4, 14, 15, 16 & 17.

Kingfisher All channels

While it will not possible to retain all overhanging branches and

fallen trees with potential for perching sites for Kingfisher, as these

may serve to block debris and impede water flow, any branches

located above flood level (defined by the trash line) will be

retained to ensure perches are present along the channels for

Kingfisher. Follow EP24

Nesting

Birds All channels

For the protection of resident birds during the bird nesting season

1st March to the 31st August, the OPW Environmental Management

Protocols and SOPs in relation to Birds will be deployed to protect

riverbank vegetation and species during woody vegetation cutting.

Prior to work on bridges the potential for nesting birds to be present

will be taken into account. The incorporation of holes and ledges will



Receptor Applicable OPW Channels

/ Embankments

Specific Avoidance and Mitigation Measures1

be considered in the design of repairs and replacement structures as

they can provide potential nesting habitat for bird species.

Fox and

Badger All channels

A buffer of 30m in relation to the use of plant machinerywillbe

deployed on Badger setts to allow for associated tunnels. Fox dens

are often also used by badgers and the same standard will apply.

Follow EP23

Invasive

Species All channels

Avoid undertaking work within stands of non-native invasive species.

Strictly adhere to OPW Invasive Species EP18D during treatment

applications.

1It should be noted that these avoidance and mitigation measures are required in addition to those standard practices detailed in

the OPWs Environemtnal Guidance Maintenance & Construction Procedures (OPW, 2019).

6.3 Mitigation for Bridge/Structure Maintenance Works

As discussed in section 2.4 it is currently unknown where and when structural drainage maintenance

operations will be required in relation to bridges. This Natura Impact Statement considers the potential

impact of maintenance operations on bridges and other structures on those watercourses screened into the

assessment. To ensure that adverse impacts do not arise on European sites and other protected species as a

result of structural maintenance operations undertaken during the period 2020-2024, EP4: Foreman Bridge

Inspection Report will be adhered to in order to identify the potential impact on both the qualifying interests

of European Sties and other protected habitats and species as well as the presence of invasive species. The

environmental procedures outlined in EP’s 14, 15, 16 & 17 will also be applied as necessary.



7 Conclusions

This Natura Impact Statement details the findings of the Stage 2 Appropriate Assessment conducted to

further examine the potential direct and indirect impacts of proposed drainage maintenance works in the

Corrib Arterial Drainage Scheme on the following European sites:


























The above sites were identified by a screening exercise that identified likely significant effects in relation

to the above sites. This screening exercise was conducted following the methodology outlined in Ryan Hanley

(2014a), which examines three “source > pathway > receptor” chains; surface water, land and air, and

groundwater pathways.

The Appropriate Assessment investigated the potential direct and indirect impacts of the proposed works

on the integrity and interest features of the above European sites, alone and incombination with other plans

and projects, taking into account the site's structure, function and conservation objectives. The three pathways

of potential impact were again used as a framework of assessment.

Where potentially significant adverse impacts were identified, a range of mitigation and avoidance

measures have been stipulated to help offset them.



As a result of this Appropriate Assessment it has been concluded, that the avoidance and mitigation measures

suggested, the proposed drainage maintenance operations for the period 2020-2024 in the Corrib Arterial

Drainage Scheme will not have a significant adverse impact on the above European sites.

To confirm this conclusion, the following checklist, taken from DEHLG (2009) has been completed.

Table 7-1 Integrity of Site Checklist (From: DEHLG, 2009)

Conservation objectives: does the project or

plan have the potential to:

Y/N

Cause delays in progress towards achieving the

conservation objectives of the sites?

N - Following mitigation, no significant adverse residual impacts have

been identified that will prevent achievement of the conservation

objectives of the identified sites.

Interrupt progress towards achieving the

conservation objectives of the sites?

N - Following mitigation, no significant adverse residual impacts have

been identified that will prevent achievement of the conservation

objectives of the identified sites.

Disrupt those factors that help to maintain the

favourable conditions of the site?

N - Potential adverse impacts identified during the screening process

can be mitigated against.

Interfere with the balance, distribution and density

of key species that are the indicators of the

favourable condition of the site?

N - Potential adverse impacts the waterfowl species of the four SPAs

identified and the faunal species within a number of other SACs can

be avoided by appropriate timing of the maintenance works..

Cause changes to the vital defining aspects (e.g.

nutrient balance) that determine how the site

functions as a habitat or ecosystem?

N - Potential adverse impacts from suspended solids and nutrient

release can be effectively mitigated.

Change the dynamics of the relationships

(between, for example, soil and water or plants

and animals) that define the structure and/or

function of the site?

N - Potential adverse impacts relating to hydrological status and

water quality have been identified which could impact on the

functioning and dynamics of the site however these can be effectively

mitigated.

Interfere with predicted or expected natural

changes to the site (such as water dynamics or

chemical composition)?

N - Potential adverse impacts from changes to the hydrological

regime, suspended solids and nutrient release can be effectively

mitigated.

Reduce the area of key habitats? N - Potential adverse impacts on SAC habitats can be effectively

mitigated to ensure no loss of key habitats.

Reduce the population of key species? N - Potential disturbance impacts to SPA bird populations, and faunal

species within a number of SACs, can be effectively mitigated to

ensure populations are not reduced. Mitigation can also be

implemented to protect populations of key species present, but for

which the SACs and SPAs are not designated (e.g. Otter, bats, Badger,

Salmon, Lamprey).

Change the balance between key species? N - Potential disturbance impacts to SPA bird populations, and faunal


ensure population dynamics are not adversely affected. Mitigation

can also be implemented to protect populations of key species present,

but for which the SACs and SPAs are not designated (e.g. Otter, bats,

Badger, Salmon, Lamprey).

Reduce diversity of the site? N - The identified mitigation measures to protect designated habitats

and species will ensure that the current diversity of the sites is

maintained.



Result in disturbance that could affect population

size or density or the balance between key

species?

N - Potential disturbance impacts to SPA bird populations, and faunal


ensure populations are not reduced. Mitigation can also be

implemented to protect populations of key species present, but for

which the SACs and SPAs are not designated (e.g. Otter, bats, Badger,

Salmon, Lamprey).

Result in fragmentation N - The proposed works will be undertaken along existing

maintenance access corridors and therefore no fragmentation will

occur.

Result in loss or reduction of key features (e.g. tree

cover, tidal exposure, annual flooding etc.)?

N - Potential adverse impacts on SAC habitats can be effectively

mitigated to ensure no loss of or reduction of key features.


References

Brew, T., Gilligan, N., 2019, Environmental Guidance: Drainage Maintenance and Construction. Series of

Ecological Assessments on Arterial Drainage Maintenance No 13. Environment Section, Office of Public Works,

Trim, Co. Meath, Ireland.

Department of Environment, Heritage and Local Government (2009) Appropriate Assessment of Plans and

Projects in Ireland - Guidance for Planning Authorities

Fossitt, J.A. (2000) A Guide to Habitats in Ireland. The Heritage Council, Dublin

JBA Consulting (2014a) Corrib Arterial Drainage Scheme: Stage 1 Appropriate Assessment Screening.

Unpublished Report.

(JBA Consulting, 2014b) Environmental River Enhancement Programme (EREP) Corrib Headford: Stage 1

Appropriate Assessment Screening. Unpublished Report.

JNCC (2014) Annex I Habitat Accounts

http://jncc.defra.gov.uk/ProtectedSites/SACselection/SAC_habitats.asp [date accessed 10th August 2014]

Kelleher, C. and Marnell, F. (2006) Bat Mitigation Guidelines for Ireland. Irish Wildlife Manuals, No. 25.

National Parks and Wildlife Service, Department of Environment, Heritage and Local Government, Dublin,

Ireland.

Kilroy, G., Dunne, F., Ryan, J., O'Connor, A., Daly, D., Craig, M., Coxon, C., Johnston, P. and Moe, H. (2008) A

Framework for the Assessment of Groundwater – Dependent Terrestrial Ecosystems under the Water Framework

Directive. Environmental Protection Agency.

NPWS (2013a) Conservation Objectives: Inner Galway Bay SPA 004031. Version 1. National Parks and

Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2013b) Conservation objectives supporting document Inner Galway Bay SPA Version 1. Conservation

Objectives Supporting Document Series. National Parks and Wildlife Service, Department of Culture, Heritage

and the Gaeltacht, Dublin, Ireland

NPWS (2013c) Ardkill Turlough SAC Site Synopsis.

https://www.npws.ie/sites/default/files/protected-sites/synopsis/SY000461.pdf [accessed 20th November

2019]

NPWS (2013d) Ballymaglancy Cave, Cong SAC Site Synopsis.


2019]

NPWS (2013e) Carrowkeel Turlough SAC Site Synopsis.


2019]

NPWS (2013f) Cloughmoyne SAC Site Synopsis.


2019]

NPWS (2013g) Clyard Kettle holes SAC Site Synopsis.

https://www.npws.ie/sites/default/files/protected-sites/synopsis/SY000461.pdf

http://www.npws.ie/media/npwsie/content/images/protectedsites/sitesynopsis/SY000461.pdf








2019]

NPWS (2013h) Greaghans Turlough SAC Site Synopsis.


2019]

NPWS (2013i) Kilglassan/Caheravoostia Turlough Complex SAC Site Synopsis.


2019]

NPWS (2013j) Levally Lough SAC Site Synopsis.


2019]

NPWS (2013k) Maumturk Mountains SAC Site Synopsis.


2019]

NPWS (2013l) Mocorha Lough SAC Site Synopsis.


2019]

NPWS (2013m) Ross Lake and Woods SAC Site Synopsis.


2019]

NPWS (2013n) Shrule Turlough SAC Site Synopsis.


2019]

NPWS (2013o) Conservation Objectives: Galway Bay Complex SAC 000268. Version 1. National Parks and

Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2013p) Conservation objectives supporting document Galway Bay Complex SAC – Turloughs Version

1. Conservation Objectives Supporting Document Series. National Parks and Wildlife Service, Department of

Culture, Heritage and the Gaeltacht, Dublin, Ireland

NPWS (2013q) Conservation objectives supporting document Galway Bay Complex SAC – Lagoons Version 1.

Conservation Objectives Supporting Document Series. National Parks and Wildlife Service, Department of


NPWS (2013r) Conservation objectives supporting document Galway Bay Complex SAC – Coastal habitats

Version 1. Conservation Objectives Supporting Document Series. National Parks and Wildlife Service,

Department of Culture, Heritage and the Gaeltacht, Dublin, Ireland

NPWS (2013s) Conservation objectives supporting document Galway Bay Complex SAC – Marine habitats















NPWS (2014a) Article 17 Habitat Assessments: Individual Habitat Reports.

http://www.npws.ie/publications/article19consultation/habitatsassessments/individualhabitatrepor

ts/#d.en.15060 [date accessed 11th September 2019]

NPWS (2014b) Monivea Bog SAC Site Synopsis.


2019]

NPWS (2014c) Towerhill House SAC Site Synopsis.


2019]

NPWS (2014d) Williamstown Turloughs SAC Site Synopsis.


2019]

NPWS (2014e) Inner Galway Bay SPA Site Synopsis.


2019]

NPWS (2014f) Lough Carra SPA Site Synopsis.


2019]

NPWS (2014g) Lough Corrib SPA Site Synopsis.


2019]

NPWS (2014h) Lough Mask SPA Site Synopsis.


2019]

NPWS (2015a) Connemara Bog Complex SAC Site Synopsis.


2019]

NPWS (2015b) Galway Bay Complex SAC Site Synopsis.


2019]

NPWS (2015c) Lough Carra/Mask Complex SAC Site Synopsis.


2019]

NPWS (2015d) Lough Corrib SAC Site Synopsis.


2019]















NPWS (2015e) Lough Lurgeen Bog/Glenamaddy Turlough SAC Site Synopsis.


2019]

NPWS (2015f) Conservation Objectives: Monivea Bog SAC 002352. Version 1. National Parks and Wildlife

Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2015g) Conservation Objectives: Connemara Bog Complex SAC 002034. Version 1. National Parks

and Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2016a) Conservation Objectives: Lisnageeragh Bog and Ballinastack Turlough SAC 000296. Version 1.

National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2016b) Conservation objectives supporting document Lisnageeragh Bog and Ballinastack Turlough SAC

– Turloughs Version 1. Conservation Objectives Supporting Document Series. National Parks and Wildlife

Service, Department of Culture, Heritage and the Gaeltacht, Dublin, Ireland

NPWS (2016c) Conservation objectives supporting document Lisnageeragh Bog and Ballinastack Turlough SAC

– Raised bog Version 1. Conservation Objectives Supporting Document Series. National Parks and Wildlife


NPWS (2016d) Conservation Objectives: Lough Lurgeen Bog/Glenamaddy Turlough SAC 000301. Version 1.

National Parks and Wildlife Service, Department of Arts, Heritage and the Gaeltacht.

NPWS (2016e) Conservation objectives supporting document Lough Lurgeen Bog/Glenamaddy Turlough SAC

– Raised bog Version 1. Conservation Objectives Supporting Document Series. National Parks and Wildlife


NPWS (2016f) Conservation objectives supporting document Lough Lurgeen Bog/Glenamaddy Turlough SAC –

Turloughs Version 1. Conservation Objectives Supporting Document Series. National Parks and Wildlife Service,


NPWS (2017a) Ardkill Turlough SAC Natura 2000 Data Form.

https://www.npws.ie/sites/default/files/protected-sites/natura2000/NF000461.pdf [accessed 20th

November 2019]

NPWS (2017b) Ballymaglancy Cave, Cong SAC Natura 2000 Data Form.


November 2019]

NPWS (2017c) Cloughmoyne SAC Natura 2000 Data Form.


November 2019]

NPWS (2017d) Clyard Kettle holes SAC Natura 2000 Data Form.


November 2019]

NPWS (2017e) Connemara Bog Complex SAC Natura 2000 Data Form.


November 2019]



https://www.npws.ie/sites/default/files/protected-sites/natura2000/NF000461.pdf






NPWS (2017f) Galway Bay Complex SAC Natura 2000 Data Form.


November 2019]

NPWS (2017g) Greaghans Turlough SAC Natura 2000 Data Form.


November 2019]

NPWS (2017h) Kilglassan/Caheravoostia Turlough Complex SAC Natura 2000 Data Form.


November 2019]

NPWS (2017i) Levally Lough SAC Natura 2000 Data Form.


November 2019]

NPWS (2017j) Lisnageeragh Bog and Ballinastack Turlough SAC Natura 2000 Data Form.


November 2019]

NPWS (2017k) Lough Carra/Mask Complex SAC Natura 2000 Data Form.


November 2019]

NPWS (2017l) Lough Corrib SAC Natura 2000 Data Form.


November 2019]

NPWS (2017m) Lough Lurgeen Bog/Glenamaddy Turlough SAC Natura 2000 Data Form.


November 2019]

NPWS (2017n) Maumturk Mountains SAC Natura 2000 Data Form.


November 2019]

NPWS (2017o) Mocorha Lough SAC Natura 2000 Data Form.


November 2019]

NPWS (2017p) Monivea Bog SAC Natura 2000 Data Form..


November 2019]

NPWS (2017q) Ross Lake and Woods SAC Natura 2000 Data Form.


November 2019]

NPWS (2017r) Shrule Turlough SAC Natura 2000 Data Form.


November 2019]















NPWS (2017s) Towerhill House SAC Natura 2000 Data Form.


November 2019]

NPWS (2017t) Inner Galway Bay SPA Natura 2000 Data Form.


November 2019]

NPWS (2017u) Lough Carra SPA Natura 2000 Data Form.


November 2019]

NPWS (2017v) Lough Corrib SPA Natura 2000 Data Form.


November 2019]

NPWS (2017w) Lough Mask SPA Natura 2000 Data Form.


November 2019]

NPWS (2017x) Lisnageeragh Bog and Ballinastack Turlough SAC Site Synopsis.


2019]

NPWS (2017y) Conservation Objectives: Maumturk Mountains SAC 002008. Version 1. National Parks and

Wildlife Service, Department of Arts, Heritage, Regional, Rural and Gaeltacht Affairs.

NPWS (2017z) Conservation objectives supporting document Maumturk Mountains SAC – Blanket bogs and

associated habitats Version 1. Conservation Objectives Supporting Document Series. National Parks and

Wildlife Service, Department of Culture, Heritage and the Gaeltacht, Dublin, Ireland

NPWS (2017aa) Conservation objectives supporting document Maumturk Mountains SAC – Najas flexilis Version

1. Conservation Objectives Supporting Document Series. National Parks and Wildlife Service, Department of


NPWS (2017ab) Conservation objectives supporting document Monivea Bog SAC – Raised bog Version 1.



NPWS (2017ac) Conservation Objectives: Lough Corrib SAC 000297. Version 1. National Parks and Wildlife

Service, Department of Arts, Heritage, Regional, Rural and Gaeltacht Affairs.

NPWS (2017ad) Conservation objectives supporting document Lough Corrib SAC – Najas flexilis Version 1.



NPWS (2018a) Williamstown Turloughs SAC Natura 2000 Data Form.


November 2019]

NPWS (2018b) Carrowkeel Turlough SAC Natura 2000 Data Form.


November 2019]










NPWS (2018c) Conservation objectives for Lough Carra/Mask Complex SAC [001774]. Generic Version 6.0.

Department of Culture, Heritage and the Gaeltacht.

NPWS (2018d) Conservation objectives for Greaghans Turlough SAC [000503]. Generic Version 6.0.

Department of Culture, Heritage and the Gaeltacht

NPWS (2018e) Conservation objectives for Clyard Kettle-holes SAC [000480]. Generic Version 6.0.


NPWS (2018f) Conservation objectives for Kilglassan/Caheravoostia Turlough Complex SAC [000504].

Generic Version 6.0. Department of Culture, Heritage and the Gaeltacht

NPWS (2018g) Conservation objectives for Levally Lough SAC [000295]. Generic Version 6.0. Department of

Culture, Heritage and the Gaeltacht.

NPWS (2018h) Conservation objectives for Ardkill Turlough SAC [000461]. Generic Version 6.0. Department

of Culture, Heritage and the Gaeltacht.

NPWS (2018i) Conservation Objectives: Ballymaglancy Cave, Cong SAC 000474. Version 1. National Parks

and Wildlife Service, Department of Culture, Heritage and the Gaeltacht.

NPWS (2018j) Conservation objectives for Carrowkeel Turlough SAC [000475]. Generic Version 6.0.


NPWS (2018k) Conservation Objectives: Ross Lake and Woods SAC 001312. Version 1. National Parks and

Wildlife Service, Department of Culture, Heritage and the Gaeltacht.

NPWS (2018l) Conservation objectives for Shrule Turlough SAC [000525]. Generic Version 6.0. Department of


NPWS (2018m) Conservation Objectives: Towerhill House SAC 002179. Version 1. National Parks and Wildlife

Service, Department of Culture, Heritage and the Gaeltacht.

NPWS (2018n) Conservation objectives supporting document– lesser horseshoe bat (Rhinolophus hipposideros)


Department of Culture, Heritage and the Gaeltacht, Dublin, Ireland.

NPWS (2018o) Conservation Objectives: Williamstown Turloughs SAC 002296. Version 1. National Parks and

Wildlife Service, Department of Culture, Heritage and the Gaeltacht.

NPWS (2018p) Conservation objectives for Lough Carra SPA [004051]. Generic Version 6.0. Department of


NPWS (2018q) Conservation objectives for Lough Corrib SPA [004042]. Generic Version 6.0. Department of


NPWS (2018r) Conservation objectives for Lough Mask SPA [004062]. Generic Version 6.0. Department of


NPWS (2019a) Conservation Objectives: Cloughmoyne SAC 000479. Version 1. National Parks and Wildlife


NPWS (2019b) Conservation Objectives: Mocorha Lough SAC 001536. Version 1. National Parks and Wildlife



NPWS (2019c). The Status of EU Protected Habitats and Species in Ireland. Volume 1: Summary Overview.

Unpublished NPWS report. Available at https://www.npws.ie/sites/default/files/publications/pdf/NPWS_2

019_Vol1_Summary_Article17.pdf [accessed: 11th September 2019]

NPWS (2019d). The Status of EU Protected Habitats and Species in Ireland. Volume 2: Habitat

Assessments.Unpublished NPWS report. Available at https://www.npws.ie/sites/default/files/publications/pd

f/NPWS_2019_Vol2_Habitats_Article17.pdf [accessed: 11th September 2019]

NPWS (2019e). The Status of EU Protected Habitats and Species in Ireland. Volume 3: Species

Assessments.Unpublished NPWS report. Available at https://www.npws.ie/sites/default/files/publications/pd

f/NPWS_2019_Vol3_Species_Article17.pdf [accessed: 11th September 2019]

O Connor, Á. (2017) Conservation objectives supporting document: Turloughs* and Rivers with muddy banks

with Chenopodion rubri p.p. and Bidention p.p. vegetation. Conservation Objectives Supporting Document

Series. National Parks and Wildlife Service, Dublin.

OPW (2007) Ecological Impact Assessment (EcIA) of the Effects of Statutory Arterial Drainage

Maintenance Activities on Water Courses of Plain to Montane levels with Aquatic Vegetation (Floating River

Vegetation).

http://www.opw.ie/media/Issue%20No.%205%20EcIA%20floating%20river%20vegetation.pdf [date

accessed 6th October 2014]

OPW (2011a) Arterial Drainage Maintenance and High Risk Channel Designation Programme 2011-2014

Habitats Directive Assessments. Environment Section Engineering Services Office of Public Works. Unpublished

Report

OPW (2011b) Arterial Drainage Maintenance Service Environmental Management Protocols and Standard

Operating Procedures. Unpublished Report

Ryan Hanley (2014a) Office of Public Works Arterial Drainage Maintenance Environmental Services 2013.

Stage 1: Appropriate Assessment Screening Methodology for the Maintenance of Arterial Drainage Schemes.

Methodology. Unpublished Report.

Ryan Hanley (2014b) Office of Public Works Arterial Drainage Maintenance Environmental Services 2013.

Stage 1: Appropriate Assessment Screening Methodology for the Maintenance of Arterial Drainage Schemes.

Moy Validation Report. Unpublished Report.

Ryan Hanley (2014c) Office of Public Works Arterial Drainage Maintenance Service 2014-2018. Source >

Pathway > Receptor Chains for Appropriate Assessment. Unpublished Report.

https://www.npws.ie/sites/default/files/publications/pdf/NPWS_2019_Vol1_Summary_Article17.pdf

https://www.npws.ie/sites/default/files/publications/pdf/NPWS_2019_Vol1_Summary_Article17.pdf

https://www.npws.ie/sites/default/files/publications/pdf/NPWS_2019_Vol2_Habitats_Article17.pdf

https://www.npws.ie/sites/default/files/publications/pdf/NPWS_2019_Vol2_Habitats_Article17.pdf

https://www.npws.ie/sites/default/files/publications/pdf/NPWS_2019_Vol3_Species_Article17.pdf

https://www.npws.ie/sites/default/files/publications/pdf/NPWS_2019_Vol3_Species_Article17.pdf


Appendix A


Corrib 2020 – 2024 Maintenance Programme:


Maintenance Details for the Headford Section:

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme

Frequency of Maintenan-ce (years)

Year of Last Maintena-nce

Timing of Works

Machine type

A B C D E F Notes

3000 Ballycolgan Flood Relief

na na Corrib Headford

2013 x Piped channel

737 CH1 Sect. 1 0 970 Corrib Headford

5 2018 Summer S/R x x x x

Tree Management 2020-2024 - IFI Request. Otter scat recorded; have regards for EP20. Have regard for EP9 Tree and Vegetation Management


2 2017 Summer S/R wcb x x x x Tree Management 2020-2024 - IFI Request. Have regard for EP9 Tree and Vegetation Management

739 CH1/1 Sect. 1

0 930 Corrib Headford

10 2017 Summer S/R x x x x Tree Management 2020-2024 - IFI Request. Have regard for EP9 Tree and Vegetation Management

740 CH1/1 Sect. 2


5 2017 Summer S/R x x

Goes dry in Summer, Tree Management 2020-2024 - IFI Request. Have regard for EP9 Tree and Vegetation Management

742 CH1/1/1 na na Corrib Headford

5 2010 Summer S/R x x Goes dry in Summer, bush cutting only

933 CH10 Sect. 2



Clear swallow hole, Tree Management 2020-2024. Area of Raised Bog (PB1 with 7110, 7120 links) recorded east of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.

935 CH10/1 Sect. 1


5 2016 Summer S/R x x x x mainly weeds, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management

936 CH10/1 Sect. 2


5 2016 Summer S/R x x x x mainly weeds, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management


5 2017 Summer S/R x x x x Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management


10 2004 Summer S/R x x x x Erosion issues, gravelly bed and banks, Tree Management 2020-


Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

2024. Have regard for EP9 Tree and Vegetation Management

943 CH10/2 na na Corrib Headford

20 2017 Summer S/R x x x Gravelly bed, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management


5 2017 Summer S/R x x x

Gravelly bed - can gather and form blockages that require removal, toss gravels at IFI request, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management


5 2017 Summer S/R x x x x silty, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management



silty, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management. previous records of lesser water-plantain recorded in channel; have regards for EP33.


5 2017 Summer S/R x x x x silty, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management

948 CH11 Sect. 1



Himalayan knotweed recorded along channel banks; have regards for EP18D. Follow Japanese Knotweed Management Strategy

949 CH11 Sect. 2



950 CH11 Sect. 3



951 CH11 Sect.4



Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management. Area of Wet heath (HH3 with 4010 links) recorded east of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.


Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes


1 2018 Summer S/R wcb x x

Salmonid channel. Have regard for EP19 Salmonid. Area of Acid oligotrophic lakes (FL2 with 3110 links) recorded at the end of the channel, have regards for EP31 Wetland. Restrict access to within established access corridors.


1 2016 Summer S/R wcb x x Salmonid channel. Have regard for EP19 Salmonid.


1 2019 Summer S/R wcb x x Salmonid channel. Have regard for EP19 Salmonid.


5 2018 Summer S/R x x silt, gravel management request by IFI


5 2015 Any S/R x x


5 2016 Any S/R x x

750 CH2/2 Sect. 1



Goes completely dry in Summer, Tree Management 2020-2024 - IFI Request. Have regard for EP9 Tree and Vegetation Management

751 CH2/2 Sect. 2


5 2018 Summer S/R x x x Goes completely dry in Summer

752 CH2/2 Sect. 3


5 Unknown Summer S/R x x x Goes completely dry in Summer






5 2019 Any S/R x x



Salmonid channel, weed cutting from outfall to 1050m. Have regard for EP9 Tree and Vegetation Management and EP19 Salmonid.


5 2017 Any S/R x x


Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

762 CH2/6 Sect. 1


1 2017 Summer S/R x x Weed cutting from outfall to 500m

763 CH2/6 Sect. 2


5 2019 Summer S/R x x salmonid channel. Have regard for EP19 Salmonid.

764 CH2/6 Sect. 3



salmonid channel, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management and EP19 Salmonid.








5 2017 Any S/R x x

890 CH3 na na Corrib Headford


salmonid channel. Have regard for EP19 Salmonid. Area of Acid oligotrophic lakes (FL2 with 3110 links) recorded at the end of the channel, have regards for EP31 Wetland. Restrict access to within established access corridors.

774 CH4 Sect. 1 Corrib Headford

1 2015 Summer Boat x x x x Duplication – this is actually C14 on Corrib Clare Scheme,


10 2009 Winter S/R x x x

Rock only, high grade – no instream works required, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management. Otter scat recorded; have regards for EP20.



salmonid channel, Have regard for EP19 Salmonid. Previous OPW record of Kingfisher sighting; have regard for EP24 Bank Nesting Birds and EP25 Birds.


10 2008 Winter S/R x x Rock only – no instream works required


Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes


10 2008 Winter S/R x x Gravel and rock only – no instream works required. Otter signs recorded; have regards for EP20.


10 – 15 2017 Summer S/R x x x x

salmonid channel, Tree Management 2020-2024 - IFI Request. Have regard for EP9 Tree and Vegetation Management


10 1996 Summer S/R x x salmonid channel; Have regard for EP19 Salmonid.


5 2016 Any S/R x x

mainly water cress. Area of Limestone/marl lakes (FL3 with 3140 links) recorded at the end of the channel, have regards for EP31 Wetland. Restrict access to within established access corridors.


5 Unknown Any S/R x x x x

Request for maintenance – Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management


5 2017 Any S/R x x


5 2016 Any S/R x x


5 2016 Any S/R x x

806 CH4/13 Sect. 1


5 2013 Any L/R x x

807 CH4/13 Sect. 2


5 2007 Any L/R x x

808 CH4/13 Sect. 3


5 2019 Any S/R x x x x Tree Management 2020-2024 - IFI Request. Have regard for EP9 Tree and Vegetation Management


5 2016 Any S/R x x


5 2016 Any S/R x x

811 CH4/13/2/1 na na Corrib Headford

5 2014 Any S/R x x


Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes


5 2016 Any S/R x x


5 2016 Any S/R x x


5 2014 Any S/R x x


5 2019 Any S/R x x

818 CH4/13/6 Sect. 1


5 2017 Any L/R x x

819 CH4/13/6 Sect. 2


5 2012 Any L/R x x

820 CH4/13/6 Sect. 3


5 2017 Any S/R x x


5 2017 Any S/R x x

823 CH4/13/6/1/1


5 2017 Any S/R x x


5 2017 Any S/R x x


5 2014 Any S/R x x

826 CH4/13/6/3/1


5 2013 Any S/R x x

827 CH4/13/6/4 na na 5 2014 Any S/R x x


5 2019 Any S/R x x x x Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management








Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes




5 2017 Any S/R x x



839 CH4/17/1 Sect. 1



salmonid channel, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management

840 CH4/17/1 Sect. 2



841 CH4/17/1 Sect. 3







salmonid channel, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management


5 2019 Any S/R x x


5 2019 Any S/R x x


5 2019 Any S/R x x


5 2004 Any S/R x x


5 2004 Any S/R x x


5 2004 Any S/R x x


5 2004 Any S/R x x


5 2017 Any S/R x x

Natura Impact Statement Page viii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



salmonid channel, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management and EP19 Salmonid.

853 CH4/20 Sect. 1



854 CH4/20 Sect. 2


5 2008 Any S/R x x


5 2016 Any S/R x x


5 2018 Any S/R x x


5 2018 Any S/R x x

858 CH4/21 Sect. 1



859 CH4/21 Sect. 2



860 CH4/21 Sect. 3



862 CH4/21/1 Sect. 2


6 2018 Any S/R x x

861 CH4/21/1 Sect.1


5 2015 Any S/R x x


5 2018 Any S/R x x


5 2018 Any S/R x x




5 2018 Any S/R x x


5 2017 Any S/R x x

Natura Impact Statement Page ix

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes


5 2017 Any S/R x x


- Unknown - - x x x


5 2012 Any S/R x x

Area of Limestone/marl lakes (FL3 with 3140 links) recorded at the end of the channel, have regards for EP31 Wetland. Restrict access to within established access corridors.


5 2017 Any S/R x x

Area of Limestone/marl lakes (FL3 with 3140 links) recorded at the end of the channel, have regards for EP31 Wetland. Restrict access to within established access corridors.


5 2018 Any S/R x x x x Tree Management 2020-2024 - IFI Request. Have regard for EP9 Tree and Vegetation Management


5 2016 Any S/R x x


5 2002 Any S/R wcb x x


5 2016 Any S/R x x


5 2016 Any S/R x x


5 2017 Any S/R x x











Natura Impact Statement Page x

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes


1 2018 Summer Boat x x x

annually with boat from outfall to 100m, every 10 years with silt bucket in patches from 600m to top. Area of rich fen and flush (PF1 with 7210 links) along the northern section of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management




1 2018 Summer Boat x x x x

Annually with boat from outfall to 100m, every 10 years with silt bucket in patches from 100m to 2100, every 5 years with silt bucket from 2100m to top, Tree Management 2020-2024 - IFI Rquest. Have regard for EP9 Tree and Vegetation Management



897 CH8 Sect. 1 c16


1 2016 Summer Boat x x x x Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management

898 CH8 Sect. 2 1975 3800 Corrib headford

5 2016 Summer L/R x x x


5 2018 Summer L/R x x x Fast flowing, very deEPcut, stones tend to fall in


5 2018 Summer L/R x x x


1 2015 Summer S/R* wcb x x S/R with extension




10 – 15 2002 Summer S/R x x Goes dry in summer, silt removal from 900m up



Natura Impact Statement Page xi

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

905 CH8/1 Sect. 1



906 CH8/1 Sect. 2





908 CH8/2 Sect. 1



909 CH8/2 Sect. 2




5 Unknown Any S/R x x x x

Tree Management 2020-2024. Area of Turlough habitat (FL6 with 3180 links) was recorded along both sides of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management. Area of Limestone/marl lakes habitat (FL3 with 3140 links) was recorded north of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.


- Unknown - - x x

Area of Turlough habitat (FL6 with 3180 links) was recorded at the end of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management.






5 Unknown Summer S/R x x Goes dry in Summer

Natura Impact Statement Page xii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes






5 2012 - - x x

Freshwater Pearl Mussel present, no instream works required, tree removal required in emergencies. Follow EP28 Freshwater Pearl Mussel. Rhododendron recorded along channel banks; have regards for EP18D.- Where possible, mature trees within the river corridor near pearl mussels should be retained to minimise bank erosion - Removal of fallen trees are to be completed by lifting clear of the channel to minimise any channel bed disturbance by branches being dragged - Trees that are at risk of falling into the river shall be removed or partialy removed by suitably trained and experienced forestry personnel at mussel locations and where necessary and technically fesible be replaced - Any removal of overhanging brances within or just above the water during periods of low flow and use a saw or secateurs, overhanging brances should be left intact unless they pose a health and safety risk - Works are not to be undertaken during periods of prolonged wet weather


5 2019 - - x x

Freshwater Pearl Mussel present, no instream works required, tree removal required in emergencies Follow EP28 Freshwater Pearl Mussel. Rhododendron recorded

Natura Impact Statement Page xiii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

along channel banks; have regards for EP18D.Previous records of Crayfish and Otter; have regards for EP22 Crayfish and EP20 Otter.


5 Unknown - - x x

Freshwater Pearl Mussel present, no instream works required, tree removal required in emergencies Follow EP28 Freshwater Pearl Mussel. Rhododendron recorded along channel banks; have regards for EP18D. Areas of Wet Grassland (GS4 with 6410 links) recorded; have regards for EP31 Wetland. Restrict access to within established access corridors.


5 2018 Summer S/R x x Goes underground from 64m to outfall, water level very low, place straw bales at end


5 2018 Summer S/R x x water level very low, place straw bales at end


- 1985 - - x x x Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management

2997 Cornamona River


5 2007 x x x

Gravel collects between 5000 and 5200 causing erosion. Gravels removed and buried on site. Tree cutting may be required. Should be checked every 5 years. A large area of Cutover Bog (PB4 with 7120 links) recorded along a a 1.9 km strech of the channel closest to Lough Corrib; have regards for EP31 Wetland. Restrict access to within established access corridors. Japanese knotweed recorded along channel banks; have regards for EP18D. Follow Japanese Knotweed Management Strategy

Natura Impact Statement Page xiv

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

1942 ED1 at Cornamona


5 2017 x

Japanese Knotweed upstream and downstream of bridge in Cornamona village - commence management plan 2020-2024. Japanese knotweed recorded along channel banks; have regards for EP18D. Follow Japanese Knotweed Management Strategy. Have regard for EP9 Tree and Vegetation Management

1941 ED1/1 at Cornamona


5 2017 x



5 Unknown x



5 Unknown x

927 F.102 na na Corrib Headford

- Unknown - - x x x Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management


5 2017 Any S/R x x


- 2017 - - x x x Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management




1 2012 - - x x x

High grade, no siltation, channel dry in summer. Goes underground at 137m to outfall. Himalayan Knotweed to be removed annually at 137m. Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management



958 F.172(CH12)


5 2017 Any S/R x x Goes underground behind school

959 F.172/1 na na Corrib Headford

5 2014 Any S/R x x

Natura Impact Statement Page xv

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes







954 F.2(A) na na Corrib Headford


955 F.2(B) na na Corrib Headford


956 F.2(C) na na Corrib Headford


957 F.2(D) na na Corrib Headford







5 2017 Any S/R x x







high water in winter, Tree Management 2020-2024. Area of Raised Bog (PB1 with 7110, 7120 links) recorded north of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management


5 2017 Any S/R x x


5 2016 Any S/R x x

Natura Impact Statement Page xvi

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes








- 1985 - - x x x x Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management


- Unknown - - x x

828 F.280A na na Corrib Headford

5 2019 Any S/R x x




5 2019 Any S/R x x


5 2009 Any S/R x x


5 Unknown Any S/R x x


5 2009 Summer S/R x x water level very low, place straw bales at end, closed in or piped, Region to check.


5 2017 Any S/R x x




5 2014 Any S/R x x



797 F.84A na na Corrib Headford




Natura Impact Statement Page xvii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes


5 2014 Any S/R x x


5 2018 Any S/R x x



868 SG15/1 na na Corrib Headford

10 2016 Any S/R x x

870 SG15/1/1 na na Corrib Headford

5 2017 Any S/R x x


5 2017 Any S/R x x


5 2016 Any S/R x x

875 SG15/1/3/1 na na Corrib Headford

5 2016 Any S/R x x

876 SG15/1/3/2 na na Corrib Headford

5 2005 Any S/R x x


10 2005 Any S/R x x


5 2019 Any S/R x x













Natura Impact Statement Page xviii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

916 SM121/1 na na Corrib Headford


918 SM121/1/1 na na Corrib Headford



5 1982 Any S/R x x

A large area of Turlough habitat (FL6 with 3180 links) was recorded along both sides of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management


5 1992 Any S/R x x

A large area of Turlough habitat (FL6 with 3180 links) was recorded along both sides of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management

888 SM122/2/1 na na Corrib Headford

5 1992 Any S/R x x x x

Tree Management 2020-2024. A large area of Turlough habitat (FL6 with 3180 links) was recorded along both sides of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management


5 2019 Any S/R x x

Natura Impact Statement Page xix

Maintenance Details for the River Clare Section:

Unique ID

Channel Ref Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

1 C1 Sect.1 0 1460 Corrib Clare

30 2008 - - x x x x

Period inspections. Next due for review in 2019, Tree Management 2020-2024. Area of tidal rivers (CW2 with 1130 links). Have regard for EP9 Tree and Vegetation Management and EP10 Silt management


30 Unknown - - x x Period inspections. Next due for review in 2019


30 Unknown - boat x x Period inspections. Next due for review in 2019





568 C10 na na Corrib Clare

5 2018 Any short reach

x x

Area of Acid oligotrophic lakes (FL2 with 3110 links) recorded at the end of the channel, have regards for EP31 Wetland. Restrict access to within established access corridors. Area of rich fen and flush (PF1 with 7210 links) along the northern section of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x

Check water levels. Area of Acid oligotrophic lakes (FL2 with 3110 links) recorded at the end of the channel, have regards for EP31 Wetland. Restrict access to within established access corridors.

572 C11/1 na na Corrib Clare


x x Check water levels at lower end

574 C11/1/1 na na Corrib Clare


x x



x x Area of Acid oligotrophic lakes (FL2 with 3110 links) recorded at the end of the channel, have regards for

Natura Impact Statement Page xx

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

EP31 Wetland. Restrict access to within established access corridors.



x x



x x



x x



x x


1 2018 Summer Boat x x

Outfall to 1500m (Gortbrack) annually. Very little maintenance required on remainder. Tree Management 2020-2024. Area of Acid oligotrophic lakes (FL2 with 3110 links) recorded at the end of the channel, have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management


5 2018 Summer short reach

x x High water in winter, mainly weeds



x x High water in winter, mainly weeds



x x

High water in winter, mainly weeds, lamprey from 0 to 300m. Area of Raised Bog (PB1 with 7110, 7120 links) recorded north of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP22 Lamprey. Species rich drain (including the species potamogeton natans and myriophyllum spicatum); have regards for EP33 Floating River Vegetation Habitat.

Natura Impact Statement Page xxi

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x Salmonid channel, lamprey from 0 to 300m. Have regard for EP19 Salmonid and EP22 Lamprey


30 Unknown - - x Periodic inspections


1 Unknown Summer Boat x x Outfall maintained annually with boat along with CH8 Sect 1 C16.


30 2014 - - x Periodic inspections. Previous record of otter activity; have regards for EP20.


30 Unknown - - x Periodic inspections



x x Silt removal required from 150 down to lake (roadbridge), periodic inspections


5 2019 Any long reach / boat

x x x

Terryland Forest Park, continue Japanese knotweed treatment started in 2018, boat used under ESB lines. Japanese knotweed recorded along channel banks; have regards for EP18D. Follow Japanese Knotweed Management Strategy. Have regard for EP9 Tree and Vegetation Management


5 2013 Any long reach

x x Swallow hole



x x



x x x

Salmonid spawning channel, self cleaning – 5 yr checks, silt at mouth, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management and EP19 Salmonid.



x x x x

Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management


5 Unknown Winter x x



x x

Natura Impact Statement Page xxii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x

High water in winter. Area of Cutover Bog (PB4 with 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x




x x High water in winter





x x

High water in winter. Area of Raised Bog (PB1 with 7110, 7120 links) recorded both sides of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.






x x



x x



x x

Area of Raised Bog (PB1 with 7110, 7120 links) recorded within the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x



x x



x x



x x Area of Raised Bog (PB1 with 7110, 7120 links) recorded within the

Natura Impact Statement Page xxiii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x



x x

Salmonid channel, silt and weed. Have regard for EP19 Salmonid and EP10 Silt Management. A number of areas of Reed and Large Sedge Swamps (FS1 with 6430 links) recorded along the channel. Restrict access to within established access corridors.



x x

Located d/s of spawning on C28, therefore can be maintained in winter. Have regard for EP19 Salmonid



x x




x x




x x




x x



5 Unknown Any short reach

x x


2976 C28/3/1/1 na na Corrib Clare


x x


Natura Impact Statement Page xxiv

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x




x x Silt removal, preferably summer but can be done in winter as enter lake before spawning bed on C28



x x



x x



x x



x x



x x




6 C3 Sect. 1 0 1700 Corrib Clare

20 2014 Summer long reach

x x x x

To be maintained as part of Clare Flood Relief Scheme – from both banks, instream silt removal and some tree cutting. Area of Limestone/marl lakes lakes (FL3 with 3140 links) recorded at the end of the channel, have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management



x x x x

To be maintained as part of Clare Flood Relief Scheme – from both banks, instream silt removal and some tree cutting


15 Unknown Summer long reach

x x x x

Tree cutting and very isolated patches of silt. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management



x x x x Tree cutting and very isolated patches of silt. Have regard for EP9

Natura Impact Statement Page xxv

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

Tree and Vegetation Management and EP10 Silt Management



x x x x

Tree cutting and very isolated patches of silt. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management



x x x x

Tree cutting and very isolated patches of silt. Have regard for EP9 tree and vegetation management and EP10 silt management



x x x x




x x x x




x x x x




x x x x




x x x x Tree cutting and very isolated patches of silt



x x x x

To be maintained as part of Clare Flood Relief Scheme – from both banks, instream silt removal and some tree cutting.



x x x x




x x x x Tree cutting and very isolated patches of silt



x x x x Rock – Tree cutting and very isolated patches of silt. Have regard for EP9 Tree and Vegetation

Natura Impact Statement Page xxvi

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

Management and EP10 Silt Management



x x x x

Rock – Tree cutting and very isolated patches of silt. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management



x x x x




x x x x

Rock – Tree cutting and very isolated patches of silt. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management. Previous record of otter activity; have regards for EP20.



x x x x




x x x x




x x x x




x x x x




x x x x To be maintained as part of Clare Flood Relief Scheme – from both

Natura Impact Statement Page xxvii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

banks, instream silt removal and some tree cutting



x x x x




x x x x




x x x x




x x x x




x x x x




x x x x




x x x x




x x x x Rock – Tree cutting and very isolated patches of silt. Have regard for EP9 Tree and Vegetation

Natura Impact Statement Page xxviii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

Management and EP10 Silt Management



x x x x




x x Mainly silt build up upstream of Milltown Bridge



x x x x



15 Unknown Winter long reach

x x x Sand and Rock – no instream maintenance required


15 2004 Winter long reach

x x x


2 , 10 2004 Summer

Boat / long reach

x x x x x Every 2 years with boat, silt and trees every 10 years



x x

Area of Cutover Bog (PB4 with 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x



x x Previous record of otter activity; have regards for EP20.



x x



x x



x x



x x



x x x x


Natura Impact Statement Page xxix

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x



x x



x x



x x


5 , 2016 Summer short reach

x x x x Trees every 10 years



x x x x




x x x x




x x x x




x x x x



annually with boat (10-year silt removal)

2018 Summer Boat / short reach

x x x High water levels – 0 to 1200m with boat, 2400m to top with machine every 10 years



x x High water levels



x x Salmonid channel. Have regard for EP19 Salmonid




Natura Impact Statement Page xxx

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x

Japanese Knotweed @ 700m - Prepare Management Plan 2020-2024. Japanese knotweed recorded along channel banks; have regards for EP18D. Follow Japanese Knotweed Management Strategy. Have regard for EP9 Tree and Vegetation Management



x x



x x



x x



x x



x x



x x



x x



x x



x x


1 , 8-10 2018 Summer short reach

x x x

0-2050m (N17) every 8-10 years with standard bucket – mainly water celery, 2050-2800m every 1-2 years with hand gang and mini-digger due to access – mainly weeds and rubbish – check gates at 2400mm regularly in winter, 2800m to top annually with weed cutting bucket – major water main crossing at Curragh

Natura Impact Statement Page xxxi

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x



x

4452 C3/18/1/2/1 na na Corrib Clare


x x



x x Done in reverse (upstream to downstream)









x x Mainly water celery.



x x Mainly water celery.



x x



x x x



x x Water levels



x x Water levels



x x Overhead ESB wires from outfall to 600m. B1 should be checked for blockages every winter



x x



x x






x x



x x

Natura Impact Statement Page xxxii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes


5 2014

Late winter / early spring

short reach

x x Bad ground conditions


5 2014


short reach



5 2012


short reach






5 , 10 2018 Summer short reach

x x

Salmonid channel , 3200m (N17 road bridge) to top should be done every 5 years. Have regard for EP19 Salmonid



x x

Salmonid channel , 4700m (N17 road bridge) to top should be done every 5 years. Have regard for EP19 Salmonid



x x Outfalls to Salmonid channel. Have regard for EP19 Salmonid






x x









x x

Area of Raised Bog (PB1 with 7110, 7120 links) recorded north of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management



x x

Natura Impact Statement Page xxxiii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x



x x



x x



x x



x x



x x



x x



x x



x x High water levels



x x Salmonid channel, check bridge at 250m every winter for blockages. Have regard for EP19 Salmonid






x x












x x



x x Skip 0-330m as landscaped. 9600m to 10000m has high grade – very little maintenance requirement

Natura Impact Statement Page xxxiv

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes







































x x Outfalls to Salmonid channel, done in reverse. Have regard for EP19 Salmonid









x x

Outfalls to Salmonid channel, 0-1200m every 10 years, 1200m to top every 5 years. Have regard for EP19 Salmonid







360 C3/35 Sect. 1 0 1500 Corrib Clare


x x Weed cutting bucket

Natura Impact Statement Page xxxv

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes






x x x x x

Mainly weed cutting bucket, patches of bank protection work near footbridges in Dunmore, check footbridges regularly in winter for blockages



x x x Mainly weed cutting bucket, have standard bucket on standby where patches of silt may need removal



x x x

Mainly weed cutting bucket, have standard bucket on standby where patches of silt may need removal. Otter signs recorded; have regards for EP20.



x x x Mainly weed cutting bucket, have standard bucket on standby where patches of silt may need removal



x x



x x x

Mainly weed cutting bucket, have standard bucket on standby where patches of silt may need removal. Area of Raised Bog (PB1 with 7110, 7120 links) recorded north of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Managementand EP10 Silt Management.Otter Holt recorded; have regards for EP20.



x x x

Mainly weed cutting bucket, have standard bucket on standby where patches of silt may need removal. Area of Cutover Bog (PB4 with 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation

Natura Impact Statement Page xxxvi

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

Managementand EP10 Silt Management



x x



x x



x x

Area of Cutover Bog (PB4 with 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Previous OPW record of Kingfisher sighting and suitable nesting cliff; have regard for EP24 Bank Nesting Birds and EP25 Birds.Previous records contain references to structures with potential for bat roosts (tree and bridge; have regard for EP26 Bats.



x x



x x



x x

414 C3/35/12 Sect. 1& 2

0 3060 Corrib Clare


x x

Salmonid channel. Have regard for EP19 Salmonid. Area of Raised Bog (PB1 with 7110, 7120 links) recorded along several sections of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management

Natura Impact Statement Page xxxvii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

416 C3/35/12/1 Sect. 1-3

0 5140 Corrib Clare


x x

Area of Raised Bog (PB1 with 7110, 7120 links) recorded along several sections of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management. Area of Cutover Bog (PB4 with 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.

419 C3/35/12/1 Sect. 4

5140 6115 Corrib Clare


x x

420 C3/35/12/1 Sect. 5



x x



x x




x x













378 C3/35/7 Sect. 1

0 825 Corrib Clare



379 C3/35/7 Sect. 2




380 C3/35/7 Sect. 3




381 C3/35/7 Sect. 4




382 C3/35/7 Sect. 5




Natura Impact Statement Page xxxviii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

383 C3/35/7 Sect. 6






x x



x x



x x



x x



x x



x x



x x

391 C3/35/8 Sect. 1

- - Corrib Clare

2016 x Deleted as duplication

393 C3/35/8 Sect. 2

- - Corrib Clare







x x



x x x Salmonid channel. Have regard for EP19 salmonid



x x



x x



x x



x x



x x High water in winter – fish at outfall







Natura Impact Statement Page xxxix

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes















x x



x x



x x x Salmonid channel. Have regard for EP19 salmonid

464 C3/47 Sect. 1 - - Corrib Clare




x x



x x



x x



x x



x x



x x









x x

497 C3/51 - - Corrib Clare


x x Salmonid channel. Have regard for EP19 salmonid

497 C3/51 Sect. 1 - - Corrib Clare




x x

Natura Impact Statement Page xl

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x



x x



x x



x x x x

Salmonid channel, trees cut by hand. Have regard for EP19 Salmonid and EP9 Tree and Vegetation Management









x x



x x






x x



x x



x x



x x



x x



x x



x x



x x

Natura Impact Statement Page xli

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x






x x



x x



x x



x x





10-15 2016 Summer long reach

x x x

Salmonid channel. Have regard for EP19 Salmonid Previous record of otter activity; have regards for EP20.



x x

Area of Raised Bog (PB1 with 7110, 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Previous record of otter activity; have regards for EP20.






x x x

Tree management required. Have regard for EP9 Tree and Vegetation Management. Previous record of otter activity; have regards for EP20.



x x x

Tree management required. Have regard for EP9 Tree and Vegetation Management. Previous record of otter activity; have regards for EP20.

Natura Impact Statement Page xlii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x

Gravelly and self cleaning – little instream maintenance, patches/blockages. Previous record of otter activity; have regards for EP20.



x x

Gravelly and self cleaning – little instream maintenance, patches/blockages. Area of raised bog (pb1 with 7110, 7120 links) recorded nadjacent to the channel; have regards for EP31 Wetland Restrict. Restrict access to within established access corridors. Previous record of otter activity; have regards for EP20.



x x




x x




x x




x x x Salmonid channel. Have regard for EP19 Salmonid









x x Patches of silt. Previous record of otter activity; have regards for EP20.



x x x Removal of islands/deposits in centre of channel & vegetation

Natura Impact Statement Page xliii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

maintenance. Have regard for EP9 Tree and Vegetation Management









x x

Area of Cutover Bog (PB4 with 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Previous record of otter activity; have regards for EP20.



x x





10, 5 2010 Summer short reach

x x

Salmonid channel – 0 to 5300m every 10 years, 5300m to top every 5 years. Have regard for EP19 Salmonid

















5 2019 Any x


5 2019 Any x









x x x Outfalls to Salmonid channel. Have regard for EP19 Salmonid

Natura Impact Statement Page xliv

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x x

Salmonid channel. Have regard for EP19 salmonid. Area of raised bog (pb1 with 7110, 7120 links) recorded nadjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.
























x x



x x






x x

Outfalls to Salmonid channel. Have regard for EP19 Salmonid. Area of Cutover Bog (PB4 with 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Area of Wet grassland (GS4 with 6410 links) recorded adjacent to channel; have regards for EP31 Wetland. Restrict access to within established access corridors.




Natura Impact Statement Page xlv

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes






x x

Outfalls to Salmonid channel. Have regard for EP19 Salmonid. Area of Raised Bog (PB1 with 7110, 7120 links) recorded north of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.









x x



x x



x x



x x



x x



x x

Area of Raised Bog (PB1 with 7110, 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x Very low water levels









x x Salmonid channel – weed cutting bucket. Have regard for EP19 Salmonid






x x

Natura Impact Statement Page xlvi

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x

Salmonid channel - needs to be checked regularly for blockages from weeds. Have regard for EP19 Salmonid


5 2012 - short reach

x x

Raised bog, gravelly so no instream works required – may have blockages caused by fallen trees. Area of raised bog (pb1 with 7110, 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 tree and vegetation management. Area of cutover bog (pb4 with 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Previous record of otter activity; have regards for EP20.




172 C3/9 Sect. 1 Corrib Clare

10 2018 Summer short reach*

x x Short reach machine with extension





10 Unknown Summer short reach*

x x

Short reach machine with extension. Area of raised bog (pb1 with 7110, 7120 links) recorded south of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.









x x

Short reach machine with extension, heavy silt management required 2020-2024. Have regard for EP10 Silt management. Area of cutover

Natura Impact Statement Page xlvii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

bog (PB4 with 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.






x x

Short reach machine with extension. Area of wet grassland (GS4 with 6410 links) recorded; have regards for EP31 Wetland. Restrict access to within established access corridors. Area of wet heath (HH3 with 4010 links) recorded east of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.






x x Short reach machine with extension. Previous record of otter activity; have regards for EP20.



x x x Short reach machine with extension, bank protection upstream of Grange Bridge 2020-2024









x x Short reach machine with extension. Previous record of otter activity; have regards for EP20.



x x



x x






x x Salmonid channel, selective spots- sandy patches. Have regard for EP19 Salmonid

Natura Impact Statement Page xlviii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes






x x Salmonid channel, done in reverse. Have regard for EP19 Salmonid













































x x



x x



x x



x x

Natura Impact Statement Page xlix

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x



x x



x x



x x



x x Water celery mainly



x x



x x






x x

Done in reverse (upstream to downstream). Previous record of otter activity; have regards for EP20.



x x



x x



x x



x x



x x









x x x x High water in winter, Tree Management 2020-2024. Have

Natura Impact Statement Page l

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

regard for EP9 Tree and Vegetation Management.



x x x High water in winter



x x



x x



x x



x x



x x



x x



x x



x x



x x



x x

663 C32/2A na na Corrib Clare


x x

664 C32/2A/1 na na Corrib Clare


x x



x x






x x




x x



x x

Natura Impact Statement Page li

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x



x x

A number of areas of Reed and Large Sedge Swamps (FS1 with 6430 links) recorded along the channel; restrict access to within established access corridors. Area of rich fen and flush (PF1 with 7210 links) along the northern section of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x





10 2018 Summer Boat / long reach

x x x x Salmonid channel – boat 0 to 1200m, machine 1200m to top. Have regard for EP19 Salmonid






x x


Annually (3 times per annum between May – Nov)

2019 Summer Boat x x









Natura Impact Statement Page lii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes








10-15 2017 Summer short reach



Annually (1-2 per annum between May – Nov) (every 5 years with machine

2017 Summer Boat / short reach

x x x Outfall to 1300m annually with boat, 1300m to top every 5 years with machine



x x























- 2012 - - x x x




x x High water in winter – mainly water celery – very little silt

Natura Impact Statement Page liii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes









x x

High water in winter. Area of Raised Bog (PB1 with 7110, 7120 links) recorded within the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.


20 (if even) 2017 Summer long reach

x x

High water in winter, silt removal with long reach machine 2020-2024. Have regard for EP10 Silt Management





Annually (3 times per annum between May – Nov)

2018 Summer Boat x x High water in winter












x x

High water in winter. Area of Acid oligotrophic lakes (FL2 with 3110 links) recorded at the end of the channel, have regards for EP31 Wetland. Restrict access to within established access corridors.






x x

High water in winter. Area of Acid oligotrophic lakes (FL2 with 3110 links) recorded at the end of the channel, have regards for EP31

Natura Impact Statement Page liv

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

Wetland. Restrict access to within established access corridors.








?? Unknown x Channel subsumed into CH1 section






x x

High water in winter. Area of Acid oligotrophic lakes (FL2 with 3110 links) recorded at the end of the channel, have regards for EP31 Wetland. Restrict access to within established access corridors. Previous records of lesser water-plantain recorded in channel; have regards for EP33.

2911 ED @ Ballyglunin

na na Corrib Clare


x x Salmonid channel. Have regard for EP19 salmonid

69 ED @ Montiagh

na na Corrib Clare



544 ED on S.G.29/2/1

na na Corrib Clare



311 Ext on C3/26/10

na na Corrib Clare


x x

658 EXT on C32 na na Corrib Clare


x x x

627 EXT-C28 F.154 P6-Q6

na na Corrib Clare


x x

112 Extra Drain at Dereen

na na Corrib Clare


x x

487 F.1016 na na Corrib Clare


x x



x x



x x

476 F.1076/1 na na Corrib Clare


x x

Natura Impact Statement Page lv

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x

607 F.1215A na na Corrib Clare



608 F.1215B na na Corrib Clare



609 F.1215C na na Corrib Clare


x x

High water in winter. Area of Raised Bog (PB1 with 7110, 7120 links) recorded north of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x



x x

Area of Raised Bog (PB1 with 7110, 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x








10 Unknown Summer short reach

x x

611 F.154 A2-B2 na na Corrib Clare





x x



x x



x x



x x



x x

Natura Impact Statement Page lvi

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes





2017 x Realigned section



x x x x

Silt removal & Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management. Area of Raised Bog (PB1 with 7110, 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x



x x



x x

2953 F.363 1460 na Corrib Clare

?? Unknown x Channel subsumed into C3 Sect. 26



x x



x x




x x



x x



x x



x x



x x




Natura Impact Statement Page lvii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x


2 – 3 2018 Sept-Nov

hand x x


Unknown x



x x


Unknown x Channel subsumed into C3/35/12 Sect 1&2

3003 f.53 na na Corrib Clare


x x x High water in winter - goes dry in summer



x x



x x



x x



x x



x x



x x



x x






x x





- 1998 - - x x x x

Maintenance required in this 5 year period, in raised bog SAC?. Area of Cutover Bog (PB4 with 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.


- 1998 - - x x

Natura Impact Statement Page lviii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x


5 , Unknown Summer short reach

x x



x x









x x



x x









x x



x x



x x



x x



x x



x x



x x






x x



x x




Natura Impact Statement Page lix

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x


10-15 2014 Summer short reach




x x



x x


Unknown x Channel subsumed into C3 Sect. 45



x x



x x



x x x x

Silt & Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management


2018 x Channel subsumed into F.772/2



x x



x x

473 F.772/3/1 na na Corrib Clare


x x



x x



x x









x x



x x x x


Natura Impact Statement Page lx

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x


Unknown x Channel subsumed into SG18/5









x x



x x



x x



x x



x x





- 2018 x Deleted as duplication






x x



x x



x x



x x



x x



x x



x x

Natura Impact Statement Page lxi

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x



x x



x x



x x



x x













1946 F3/196 off C27 (C5-D5?)

na na Corrib Clare


x x

612 P196/1 na na Corrib Clare



614 P196/5 na na Corrib Clare



615 P196/6 L5-M5, F.154

na na Corrib Clare



610 P196/8 P5-Q5

na na Corrib Clare



2998 S.G.18/1A na na Corrib Clare


x x

624 S.G.55/1 na na Corrib Clare





x x



x x

Natura Impact Statement Page lxii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x



x x




x x

Area of Raised Bog (PB1 with 7110, 7120 links) recorded within the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Area of rich fen and flush (PF1 with 7210 links) along the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.

648 S.G.68/7/1 na na Corrib Clare


x x



x x

437 S.G5/1 na na Corrib Clare


x x

438 S.G5/1/1 na na Corrib Clare


x x

554 S.R 32/1 na na Corrib Clare


x x

2244 SG Wormhole na na Corrib Clare


x x

436 SG.16/1 na na Corrib Clare



441 SG.18/1/1 na na Corrib Clare


x x Maintained up to road bridge only



x x Maintained up to road bridge only


- Unknown - - x Probable maintenance required in this 5 year period

Natura Impact Statement Page lxiii

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes


- Unknown - - x

Probable maintenance required in this 5 year period. A large area of Turlough habitat (FL6 with 3180 links) was recorded along both sides of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management. Area of Raised Bog (PB1 with 7110, 7120 links) recorded north of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.


- Unknown - - x

Probable maintenance required in this 5 year period. A large area of Turlough habitat (FL6 with 3180 links) was recorded along both sides of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management

430 SG.18/4/1/1 na na Corrib Clare

- Unknown - - x

Probable maintenance required in this 5 year period. A large area of Turlough habitat (FL6 with 3180 links) was recorded along both sides of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management


- Unknown - - x

Probable maintenance required in this 5 year period. A large area of Turlough habitat (FL6 with 3180 links) was recorded along both sides of the channel; have regards for EP31 Wetland. Restrict access to within established access

Natura Impact Statement Page lxiv

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management. Area of Raised Bog (PB1 with 7110, 7120 links) recorded north of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.

432 SG.18/4/2/1 na na Corrib Clare

- Unknown - - x

Probable maintenance required in this 5 year period. Area of Raised Bog (PB1 with 7110, 7120 links) recorded north of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management. Rea of Cutover Bog (PB4 with 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. An area of Bog Woodland (WN7 with 910 links) was recorded; have regards for EP30 Alluvial (Wet Woodland).


- Unknown - - x

Probable maintenance required in this 5 year period. A large area of Turlough habitat (FL6 with 3180 links) was recorded along both sides of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management. Area of Raised Bog (PB1 with 7110, 7120 links) recorded adjacent to the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



Natura Impact Statement Page lxv

Unique ID


Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x















x x



x x Check swallow hole for blockages annually






x x

Skip 0-100m. A large area of Turlough habitat (FL6 with 3180 links) was recorded at the end of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Have regard for EP9 Tree and Vegetation Management and EP10 Silt Management



x x

439 SG18/1 na na Corrib Clare


x x

434 SG18/5 na na Corrib Clare


553 SM103/1 na na Corrib Clare


x x x x


552 SM93/1 na na Corrib Clare

- Unknown - - x x x x


Maintenance Details for the Lough Mask Section:

Natura Impact Statement Page lxvi

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

965 CM1 na na Corrib Mask

- 2016 - - x x

Bank protection upstream of B3 near Cong Village during 2020-2024. Have regard for EP11 Bank Protection

970 CM1/1 na na Corrib Mask

- 2004 - - x x x General maintenance 2020-2024


- 2018 - - x

No maintenance required in this 5 year period. Previous record of Otter activity; have regards for EP20.


- Unknown

- - x No maintenance required in this 5 year period


- 2014 - - x No maintenance required in this 5 year period


- Unknown



- Unknown



10 Unknown

Winter short reach

x x x



x x x

Salmonid channel, General maintenance 2020-2024 to end of channel. Have regard for EP19 Salmonid



x x



x x x General maintenance 2020-2024



x x



x x

976 CM4 Sect. A

0 5330 Corrib Mask

10 2018 Winter (early)

long reach

x x x Prabable maintenance from 5300m upstream 2020-2024

977 CM4 Sect. B

5330 22700 Corrib Mask


x x x x

Ballinrobe Br. - Hollymount Br. 5300-22700m – Salmonid channel - check. Have regard for EP19 Salmonid

Natura Impact Statement Page lxvii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

980 CM4 Sect. C



x x x

Hollymount Br. - Sheepwash Br. 22700-28700m – silt in patches – lot of fisheries works done, Tree Management 2020-2024 - IFI request D/S of B13. Have regard for EP9 Tree and Vegetation Management and EP19 Salmonid

981 CM4 Sect. D



x x Sheepwash Br. Crossboyne Br. 28700-37800m.

983 CM4 Sect. E



x x x x

Crossboyne Br. Tootagh 37800-45400m – previous tree cutting works from 37800-41800m, Knotweed Management Plan Required.Have regard for EP18A Standard Biosecurity, EP18B High Security, and in particular EP18D Invasive Plants

984 CM4 Sect. F


1, 10 2018 Summer Boat / long reach

x x x x x

Tootagh - Brickeens Br. 45400-50200m (45400-48700m annually with boat) check Kilknock bridge monthly for blockages. Tree Management 2020-2024 - IFI request U/S & D/S of B28, Knotweed Management Plan Required.Have regard for EP18A Standard Biosecurity, EP18B High Security, and in particular EP18D Invasive Plants. Have regard for EP9 Tree and Vegetation Management

985 CM4 Sect. G



x x Brickeens Br. To END 50200-57600m

Natura Impact Statement Page lxviii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x



x x

1008 CM4/12/1 na na Corrib Mask


x x

1009 CM4/12/1/1

na na Corrib Mask


x x

1010 CM4/12/1/1/1

na na Corrib Mask


x x

1011 CM4/12/1/2

na na Corrib Mask


x x









x x x



x x



x x



x x



x x

1019 CM4/17/1/1

na na Corrib Mask


x x

1020 CM4/17/1/1/1

na na Corrib Mask


x x



x x

Natura Impact Statement Page lxix

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x

4455 CM4/18 (Proposed)

na na Corrib Clare

N/A x Deleted from Maps – Never constructed



x x



x x



x x



x x



x x



x x

1028 CM4/20/1/1

na na Corrib Mask


x x


1 , 5 2018 Any short reach

x x

220m-1080m annually to remove water celery. Have regard for EP9 tree and vegetation management.have regards for EP18a standard biosecurity, EP18b high security, and EP18c boat cleaning.



x x



x x



x x Labelled incorrectly on map



x x

1400m-1600m annually to remove water celery. Have regard for EP9 tree and vegetation management. Have

Natura Impact Statement Page lxx

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

regards for EP18a standard biosecurity, EP18b high security, and EP18c boat cleaning.



x x

1036 CM4/24/1/1

na na Corrib Mask


x x






x x Outfall to salmonid channel. Have regard for EP19 Salmonid

1039 CM4/25/1/1

na na Corrib Mask











x x



x x



x x



x x

Salmonid channel – 3100-4700m little maintenance requirement due to high grade. Have regard for EP 19 salmonid



x x



x x



x x



x x



x x

Natura Impact Statement Page lxxi

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x x x

Salmonid channel – 0-5050m every 10 years, 5050m-8550m every 5 years, Tree Management 2020-2024 - IFI request. Have regard for EP9 Tree and Vegetation Management and EP19 Salmonid



x x

Salmonid channel – 0-1100m and 2700m to top little maintenance requirement, Have regard for EP19 Salmonid

1064 CM4/32/1/1

na na Corrib Mask


x x

0-250m – little maintenance requirement, 250-1000m annually to remove water celery. Have regard for EP9 tree and vegetation management. Have regards for ep18a standard biosecurity, ep18b high security, and EP18c boat cleaning.

1065 CM4/32/1/1/1

na na Corrib Mask


x x

0-500m annually to remove water celery, 500-1180m every 5 years. Have regard for EP 9 tree and vegetation management. Have regards for EP 18a standard biosecurity, EP 18b high security, and EP 18c boat cleaning.



x x Outfalls to Salmonid channel. Have regard for EP 19 Salmonid









x x

Natura Impact Statement Page lxxii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x

Salmonid channel – 2800-330m annually to remove water celery, rest every 5 years. Have regard for EP 9 Tree and Vegetation Management and EP 19 Salmonid. Have regards for EP 18A Standard Biosecurity, EP 18B High Security, and EP 18C Boat Cleaning.












x x Skip 1000m-1300m as piped



x x

1078 CM4/35/1/1

na na Corrib Mask


x x



x x



x x



x x



x x



x x



x x



x x



x x

Natura Impact Statement Page lxxiii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x 0-150m – little maintenance requirement



x x



x x



x x



x x



x x

Salmonid channel, lot of fisheries work in the past – silt and weed in patches. Have regard for EP 9 Tree and Vegetation Management, EP 10 Silt Management and EP 19 Salmonid. Have regards for EP 18A Standard Biosecurity, EP 18B High Security, and EP 18C Boat Cleaning.



x x

Salmonid channel, 0-2000m every 10 years silt removal, 2100m to top annually to remove water celery. Have regard for EP 9 Tree and Vegetation Management, EP 10 Silt Management and EP 19 Salmonid. Have regards for EP 18A Standard Biosecurity, EP 18B High Security, and EP 18C Boat Cleaning.

1096 CM4/43/1/1

na na Corrib Mask


x x Annually to remove water celery. Have regard for EP 9 tree and vegetation management.

Natura Impact Statement Page lxxiv

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x

1098 CM4/43/2/1

na na Corrib Mask


x x



x x



x x

1101 CM4/43/4/1

na na Corrib Mask


x x



x x



x x



x x



x x



x x



x x Salmonid channel – skip 1100-1550m as landscaped. Have regard for EP 19 Salmonid



x x Salmonid channel. Have regard for EP 19 Salmonid

1110 CM4/47/2/1

na na Corrib Mask


x x

1111 CM4/47/2/1/1

na na Corrib Mask


x x




1113 CM4/47/3/1

na na Corrib Mask


x x



x x



x x

Natura Impact Statement Page lxxv

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x


1 , 10 2018 Summer Boat / long reach

x x x

Salmonid channel, 420-620m once per annum with boat, 1100m to top 4 times per annum between May Oct, Weeds must be removed from channel to prevent blocking bridges in town, every ten years perhaps with machine. Have regard for EP 9 Tree and Vegetation Management and EP 19 Salmonid. Have regards for EP 18A Standard Biosecurity, EP 18B High Security, and EP 18C Boat Cleaning.



x x

997 CM4/5/1/1 na na Corrib Mask


x x






x x



x x



x x



x x



x x



x x



x x

Natura Impact Statement Page lxxvi

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x



x x



x x



x x



x x









x x



x x



x x


5 2018 Summer boat x x

Salmonid channel, fen habitat. 1300m (Keel Bridge) to end only. Have regard for EP 19 Salmonid and EP 31 Wetland



1161 CM5/10 Sect. A

0 4500 Corrib Mask

1 2017 September

boat x x Salmonid channel. Have regard for EP 19 Salmonid

1162 CM5/10 Sect.B


10 2018 Winter short reach

x x x

Tree Management 2020-2024 - IFI request - Towerhill House SAC – Bats. Have regard for EP 9 Tree and Vegetation Management. Have regard for EP 26 Bats. Area of Raised Bog (PB1 with 7110 links) recorded

Natura Impact Statement Page lxxvii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

on the western banks of the mouth of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors. Previous records of Otter activity have regards for EP20.


1, 5, 10 2018 Any Boat / Short Reach

x x x

0-600m annually with boat, every 10 years silt removal, 600m to top every 5 years silt removal. Have regard for EP10 silt management

1165 CM5/10/1/1

na na Corrib Mask


x x


- Unknown



10 2002 Winter x x x

Minor tree pruning only. Towerhill House SAC – Bats. Have regard for EP9 Tree and Vegetation Management and EP26 Bats.


10 Unknown

Winter x x x

Minor tree pruning only. Towerhill House SAC – Bats. Have regard for EP9 Tree and Vegetation Management and EP26 Bats.


- Unknown


1170 CM5/10/5/1

na na Corrib Mask


x x

Salmonid channel, silt & weeds. Have regard for EP9 Tree and Vegetation Management, EP10 Silt Management and EP19 Salmonid

1171 CM5/10/5/1/1

na na Corrib Mask


x x Salmonid channel, silt & weeds. Have regard for EP9 Tree and Vegetation Management, EP10

Natura Impact Statement Page lxxviii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

Silt Management and EP19 Salmonid



x x

1173 CM5/10/6/1

na na Corrib Mask


x x

1174 CM5/10/6/2

na na Corrib Mask


x x

1175 CM5/10/6/3

na na Corrib Mask


x x

1177 CM5/10/6/3/1

na na Corrib Mask


x x



x x



x x

Area of Raised Bog (PB1 with 7110 links) recorded on the western banks of the southern end of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x

Area of Raised Bog (PB1 with 7110 links) recorded along both banks of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x x x

Salmonid channel, Tree Management 2020-2024 - IFI request. Have regard for EP9 Tree and Vegetation Management and EP19 Salmonid



x x

Salmonid channel. Have regard for EP19 Salmonid. Previous record of elodea sp. Waterweed in the channel; no 2019 record,

Natura Impact Statement Page lxxix

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

however, have regard for EP18A Standard Biosecurity, EP18B High Security, and EP18C Boat Cleaning.



x x Channel may be maintained by locals



x x High water levels in winter, also overwintering birds. Have regard for EP25 Birds



x x



x x High water levels in winter



x x



x x x x




x x



x x Salmonid channel.Have regard for EP19 Salmonid.



x x Salmonid channel. Have regard for EP19 Salmonid.

1142 CM5/9 Sect. A

0 4500 Corrib Mask



1144 CM5/9 Sect. B












x x

Natura Impact Statement Page lxxx

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x







1153 CM5/9/4/1/1

na na Corrib Mask



1154 CM5/9/4/1/1/1

na na Corrib Mask











x x

1132 CM5A na na Corrib Mask



10 2011 September

short reach

x x


10 2011 September

short reach

x x


10 2011 September

short reach

x x



x x x

Salmonid channel, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management and EP19 Salmonid. Previous record of Otter activity; have regards for EP20. Previous records of both Japanese Knotweed and Himalayan Balsam; have regards for EP18A Standard Biosecurity, EP18B High

Natura Impact Statement Page lxxxi

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

Security, and EP18D Invasive Plants.



x x x x

Salmonid channel, bank erosion issues near outfall. Have regard for EP19 Salmonid and EP10 Silt Management.


- Unknown



- Unknown



- Unknown



- Unknown




x x



x x




10-15 2017 Winter long reach

x x

Salmonid channel, very fast flowing – flood rapidly. No instream maintenance required. Previous records of Himalayan Balsam; have regards for EP18A Standard Biosecurity, EP18B High Security, and EP18D Invasive Plants.


10 1999 Summer (late)

short reach

x x x

Previous record of Otter activity; have regards for EP20. Previous records of Himalayan Balsam; have regards for EP18A Standard Biosecurity, EP18B High Security, and EP18D Invasive Plants.

Natura Impact Statement Page lxxxii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



short reach

x x



short reach













x x x x





1209 CM9/3/3/1/1

na na Corrib Mask



1210 CM9/3/3/1/2

na na Corrib Mask



1211 CM9/3/3/1/2/1

na na Corrib Mask



1212 CM9/3/3/1/2/2

na na Corrib Mask



1213 CM9/3/3/1/3

na na Corrib Mask





x x



x x x x

Salmonid channel, Tree Management 2020-2024. Have regard for EP9 Tree and Vegetation Management and EP19 Salmonid.

1219 CM9/3/3/3/1

na na Corrib Mask



Natura Impact Statement Page lxxxiii

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes

1220 CM9/3/3/3/2

na na Corrib Mask



1221 CM9/3/3/3/2/1

na na Corrib Mask



1223 CM9/3/3/3/3

na na Corrib Mask



1224 CM9/3/3/3/3/1

na na Corrib Mask



1225 CM9/3/3/3/3/1/1

na na Corrib Mask



1226 CM9/3/3/3/3/1/1/1

na na Corrib Mask



1227 CM9/3/3/3/4

na na Corrib Mask






1229 CM9/3/3/4/1

na na Corrib Mask



1230 CM9/3/3/4/2

na na Corrib Mask





x x x

Tree cutting required every 10 year (last cut in 2014). Have regard for EP9 Tree and Vegetation Management



x x

Salmonid channel, done in reverse (upstream to downstream). Have regard for EP19 Salmonid.



x x



x x


0 Unknown

- - x Salmonid channel. Have regard for EP19 Salmonid.

990 F.141 na na Corrib Mask

1 , 10 2019 Summer Boat / Short Reach

x x x x Annually with boat, every 10 years with machine

Natura Impact Statement Page lxxxiv

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x



x x

2902 F218 na na Corrib Mask


x x Salmonid channel. Have regard for EP19 salmonid.

1187 F287(A) na na Corrib Mask

- Unknown

- - x

No maintenance required in this 5 year period. Previous record of Otter activity; have regards for EP20.



x x



x



x x



x x



x x



x x

1949 SM 111/1 na na Corrib Mask

0 Unknown

- - x

Channel deleted. Area of Turlough (FL6 with 3180 links) recorded along the majority of the channel; have regards for EP31 Wetland. Restrict access to within established access corridors.



x x



x x

1052 SM 111/4/1

na na Corrib Mask


x x

1051 SM 111/4A

na na Corrib Mask


x x

Natura Impact Statement Page lxxxv

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x

1055 SM 119/1/1

na na Corrib Mask


x x

1057 SM 119/2/1

na na Corrib Mask


x x

1158 SM100/1 na na Corrib Mask


x x


- Unknown



- Unknown




x x



x x

1048 SM111/3/1 na na Corrib Mask


x x

1049 SM111/3/1/1

na na Corrib Mask


x x



x x

1092 SM112/1A na na Corrib Mask


x x


10 Unknown

Any short reach

x x



x x



x x



x x


- Unknown




x x

Natura Impact Statement Page lxxxvi

Unique ID

Channel Ref

Start of Chainage

Finish of Chainage

Scheme



Timing of Works

Machine type

A B C D E F Notes



x x




- Unknown



- Unknown




x x x



x x



x x




Appendix B


Maps of Annexed Habitats recorded during

the 2019 Ecological Survey:






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OPW Arterial Drainage · 2020. 4. 21. · Corrib Arterial Drainage Scheme Natura Impact Statement...

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