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Oweninny Wind Farm

Oweninny Bellacorick Iron Flush

Appendix 14

Natura Impact Statement (SCREENING)

Oweninny Wind Energy Project Environmental Impact Statement County Mayo May 2013

APPENDIX A.

SCREENING

Ballacorick Iron Flush Appendix 14A

OWENINNY WINDFARM PROPOSAL

BELLACORICK IRON FLUSH

HYDRO-GEOLOGICAL INVESTIGATIONS

NATURA IMPACT STATEMENT

‘SCREENING’

Prepared for

ESB International

by

Biosphere Environmental Services

29 La Touche Park, Greystones, Co. Wicklow

Tel: 01-2875249 E-mail: [email protected]

Bellacorick Iron Flush Hydro-geological Survey Natura Impact Statement: Screening

ESB International Biosphere Environmental Services

ii

TABLE OF CONTENTS

1. INTRODUCTION........................................................................................................................1

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

1.2 Regulatory Context .............................................................................................................1

1.3 Stages of the Appropriate Assessment (AA) ..................................................................2

2. SCREENING FOR APPROPRIATE ASSESSMENT ...........................................................3

2.1 Description of the Project...................................................................................................3

2.1.1 Purpose & scope ....................................................................................................................3

2.1.2 Background .............................................................................................................................4

2.1.3 Site sensitivity mapping & protection ..................................................................................4

2.1.4 Site walkover survey & drainage mapping & hydrochemistry mapping .........................5

2.1.5 Peat morphology & substrate mapping...............................................................................5

2.1.6 Window sampling & piezometer installation.......................................................................6

2.1.7 Topographical survey ............................................................................................................8

2.1.8 Sampling & on-going monitoring..........................................................................................9

2.2 Sites Identification.............................................................................................................10

2.2.1 Bellacorick Iron Flush candidate Special Area of Conservation................................11

2.3 Identification and Assessment of Potential Impacts on Bellacorick Iron Flush cSAC

............................................................................................................................................11

2.3.1 Impacts by personnel on site ..........................................................................................12

2.3.2 Impacts by intrusive works on site .................................................................................12

2.4 Analysis of “In-combination” Effects...............................................................................13

2.5 Screening Conclusion and Statement ...........................................................................14

2.6 References.........................................................................................................................15

APPENDIX 1 : Site Synopsis

Figure 1: Bellacorick Iron Flush cSAC : Proposed Investigation Map

1. INTRODUCTION

1.1 Background

This report has been prepared by Dr. Brian Madden of BioSphere Environmental

Services, in association with ESB International and Hydro Environmental Services to

determine the potential impacts, if any, of the plan for a hydro-geological

investigation (in relation to the Oweninny Wind Farm project) at the Bellacorick Iron

Flush candidate Special Area of Conservation. The assessment will determine the

appropriateness, or otherwise, of the proposed project in the context of the

conservation objectives of the site.

The purpose of the proposed study is to determine the potential for impact on the

hydro-geology of the fen which could arise from the proposed construction of wind

turbine foundations in its vicinity.

The assessment is in support of an application to the Department of Arts, Heritage

and the Gaeltacht for permission to carry out an operation or activity on a site to

which the European Communities (Natural Habitats) Regulations 1997 (No. 94 of

1997) as amended, apply, in accordance with Regulation 14 of those Regulations.

1.2 Regulatory Context

The Council Directive 92/43/EEC on the Conservation of Natural Habitats and of Wild

Flora and Fauna better known as “The Habitats Directive” provides the framework for

legal protection for habitats and species of European importance. Articles 3 to 9

provide the legislative means to protect habitats and species of Community interest

through the establishment and conservation of an EU-wide network of sites known as

Natura 2000. These are Special Areas of Conservation (SACs) designated under the

Habitats Directive and Special Protection Areas (SPAs) designated under the

Conservation of Wild Birds Directive (79/409/EEC) (better known as “The Birds

Directive”).

Article 6(3) and 6(4) of the Habitats Directive set out the decision-making tests for

plans and projects likely to affect Natura 2000 sites (Annex 1.1). Article 6(3)

establishes the requirement for Appropriate Assessment (now termed Natura Impact

Statement):

“Any plan or project not directly connected with or necessary to the

management of the [Natura 2000] site but likely to have a significant effect

thereon, either individually or in combination with other plans and projects,

shall be subjected to appropriate assessment of its implications for the site in

view of the site’s conservation objectives. In light of the conclusions of the

assessment of the implication for the site and subject to the provisions of



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paragraph 4, the competent national authorities shall agree to the plan or

project only after having ascertained that it will not adversely affect the

integrity of the site concerned and, if appropriate, after having obtained the

opinion of the general public”

The Habitats Directive promotes a hierarchy of avoidance, mitigation and

compensatory measures. First the project should aim to avoid any negative impacts

on European sites by identifying possible impacts early in the planning stage, and

designing the project in order to avoid such impacts. Second, mitigation measures

should be applied, if necessary, during the AA process to the point, where no

adverse impacts on the site(s) remain. If the project is still likely to result in adverse

effects, and no further practicable mitigation is possible, then it is rejected. If no

alternative solutions are identified and the project is required for imperative reasons

of overriding public interest (IROPI test) under Article 6 (4) of the Habitats Directive,

then compensation measures are required for any remaining adverse effect.

1.3 Stages of the Appropriate Assessment (AA)

This Natura Impact Statement has been undertaken in accordance with the

European Commission Methodological Guidance on the provision of Article 6(3) and

6(4) of the ‘Habitats’ Directive 92/43/EEC (EC 2001) and the European Commission

Guidance ‘Managing Natura 2000 Sites’. The Guidance for Planning Authorities

issued by the Department of Environment, Heritage and Local Government

(December 2009) is also adhered to.

There are four distinct stages to undertaking an AA as outlined in current EU and

DOEHLG guidance:

1. Appropriate Assessment Screening

2. Appropriate Assessment

3. Assessment of Alternatives in cases where significant impact cannot be

prevented

4. Where no alternatives exist, an assessment of compensatory issues in the case

of projects or plans which can be considered to be necessary for imperative

reasons of overriding public interest (IROPI)



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2. SCREENING FOR APPROPRIATE ASSESSMENT

Screening determines whether appropriate assessment is necessary by examining:

1. Whether a plan or project can be excluded from AA requirements because it is

directly connected with or necessary to the management of a Natura 2000 site.

2. Whether the project will have a potentially significant effect on a Natura 2000 site,

either alone or in combination with other projects or plans, in view of the site’s

conservation objectives.

Screening involves the following:

i. Description of plan or project

ii. Identification of relevant Natura 2000 sites, and compilation of

information on their qualifying interests and conservation objectives

iii. Assessment of likely effects – direct, indirect and cumulative –

undertaken on the basis of available information as a desk study or

field survey or primary research as necessary

iv. Screening Statement with conclusions

2.1 Description of the Project

There follows a detailed method statement for the work required for the proposed

project.

2.1.1 Purpose & scope

The Bellacorick Iron Flush cSAC is located within the Bord na Mona former peat

harvesting site at Oweninny in County Mayo. Bord na Mona in a joint venture with

ESB Wind Development intend to apply for planning permission for a substitute wind

farm development on the site. The Bellacorick Iron Flush cSAC, which is in the

ownership of An Taisce and the National Parks and Wildlife Services, was identified

as a very sensitive area requiring special consideration and a specific study relating

to the hydrology of the site. The proposed study will entail groundwater level

measurement within and around the site and sampling for hydrochemistry.



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The following defines the methods, equipment and procedures for the undertaking of

a Phase 1 and Phase 2 site investigation at Bellacorick Iron Flush cSAC. A

preliminary site visit and report was previously undertaken by Hydro Environmental

Services (HES) which included a desk study and initial characterisation of the cSAC.

The preliminary report was based on a walkover survey (outside the perimeter of the

cSAC) and existing information.

2.1.2 Background

It is proposed that the Phase 1 investigation will comprise the following elements.

The procedures are discussed in detail below.

• Site walkover survey and drainage mapping;

• Hydrochemistry mapping;

• Peat morphology and substrate survey;

It is proposed that the Phase 2 investigation will comprise the following elements.

• Window sampling and piezometer installation;

• Topographic survey; and,

• Sampling & on-going Monitoring.

2.1.3 Site sensitivity mapping & protection

Prior to any investigation works taking place, there will be an updated ecological

survey of the cSAC undertaken by an ecologist. This will focus on the wet grassland

and fen/flush zones of the site, with particular emphasis on the distribution of Marsh

Saxifrage. Further, the ecologist will be present on-site to oversee all investigation

works. (Oweninny Power Ltd have appointed BioSphere Environmental Services as

project ecologists, with Dr John Conaghan acting as principal ecologist for this

project)

The ecological survey will delineate sensitive areas of the cSAC and areas that

should be completely avoided during the investigation works. It is anticipated that the

core wet grassland area which supports the main population of Marsh Saxifrage will

be an exclusion zone. Also, to minimise impacts on vegetation and blanket bog,

walking routes to and from proposed investigation areas within the cSAC boundary

will be pre-marked by the ecologist. The sensitive areas and dedicated walking

routes will be marked using bamboo canes with tape strands and/or tape strands

attached to clumps of vegetation. Other measures to reduce impacts on the cSAC

include:

• No peat digging or extraction outside of selected investigation areas;

• All investigation areas will be reinstated after works are completed and inspected

by ecologist;



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• Use of automatic data loggers to reduce the need to return to the site frequently

to undertake manual monitoring;

• Refuelling of generator will be undertaken outside of cSAC boundary;

• The generator will be placed on a drip tray during use;

• Spill kits will be available in case of accidentals spills;

• Good house keeping practices; and,

• No disposal of waste (liquid or solid) will be allowed.

2.1.4 Site walkover survey & drainage mapping & hydrochemistry mapping

Resources and Equipment

• 1 no. HES site staff and 1 no. ecologist;

• YSI multi-meter hand held hydrochemistry probe;

• Hand held GPS;

• Camera; and,

• Required working area approximately 1m2

Procedure

A walkover survey of the cSAC and the surrounding area will be undertaken which

will include mapping of drainage features, flow directions and principal discharge

zones. Field hydrochemistry measurements (electrical conductivity, pH, temperature

& DO) of drain water and any flushes (with mineral rich groundwater) will be

undertaken to determine the origin of flows and seepages. Hydrochemistry

measurements will be undertaken using a handheld YSI Multi-meter probe.

Locations of measurement points will be recorded by means of a hand held GPS.

Walking routes within the cSAC will be advised by the ecologist.

2.1.5 Peat morphology & substrate mapping

Resources and Equipment


• 1m length plastic peat probes;

• Hand held steel gouge auger set (see Plate A);

• Hand held GPS;

• Camera; and,

• Required working area approximately 1m2.



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Plate A. Standard Gouge Auger Set.

Procedure

Characterisation of peat and subsoil morphological conditions within the cSAC will be

undertaken by carrying out peat depth probing and gouge augering. Peat depth

probing, by means of push in plastic Rods (20mm diameter), will be undertaken at a

25m grid spacing which can be reduced or increased depending on the

geomorphology of the bog. It is expected that between no. 20 – 30 peat probes will

be undertaken. It is expected that between no. 10 – 20 gouge cores will be

undertaken.

Gouge augers are steel cylindrical chambers (30mm diameter) which are pushed into

the peat/subsoil, twisted and then recovered to display a full and virtually undisturbed

profile of the peat and underlying mineral subsoil (where present). Peat and subsoil

profile logging will be undertaken as per Von Post Scale & BS5930. Locations of

probe points will be recorded by means of a hand held GPS. Walking routes and

peat probe locations between probe locations will be advised by the ecologist.

The holes created by the peat probe and gouge cores will only exist temporarily as

the hole will collapse and the hole will reseal itself.

2.1.6 Window sampling & piezometer installation

Resources & Equipment


• Hydraulic hammer & power packr (Plate B shows a picture of the hammer and

power pack). It weighs 72kg, and has approximately dimensions of 74x62x55cm);

• Steel driving rods (0.5m & 1m lengths) & steel window sampler tubes (1m & 2m

lengths);



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• Window sampler mechanical jack & hoist bars (the jack is 30x30cm, and the bars

are 2.0m box steel, see Plate C);

• 18mm x 3m plastic piezometer lengths;

• Bentonite clay & sand;

• General tools; and,


Plate B. Hydraulic Power Pack & Hammer Plate C. Jack and hoist bars (green)

Procedure

A network of nested piezometers for groundwater level monitoring will then be

installed within the cSAC and at its boundaries by means of window sampling (see

steps below) which is a technique that uses portable coring equipment to recover

narrow cores of peat and subsoil for visual logging and sampling. Nested

piezometers are a group of piezometers installed at different depths to measure

vertical water level gradients within the peat (i.e. phreatic surface & deep peat). The

procedure will include the following steps.

• Site staff to locate drill target by means of GPS or otherwise;

• Mobilise equipment to drill target manually;

• Adhere to walking paths and drill locations set by the ecologist;

• Window sampling tubes are then driven into ground by means of hydraulic

hammer;

• Once the sampling tube has reached its maximum depth below ground level the

tube is withdrawn by a mechanical jack & hoist bars;

• Window sampler tube is then laid out on ground and logged by site staff;

• Subsoil samples are taken and are placed into clearly marked containers;

• The remainder of the subsoil material is removed from the window sampler and

kept in waste disposal bag and removed from the site;



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• The process is repeated until the required depth is reached or until refusal is

met;

• Piezometers tubes are installed once the required depth is reached;

• Drill target site is cleared and equipment is moved to next drill target as required.

In relation to deep subsoil piezometers installation the following construction method

is proposed:

• Create hole in peat down to subsoil level by using gouge core;

• 3” PVC well casing is then pushed down manually through hole in peat and into

underlying mineral subsoil where a seal between the casing and clay is created;

• Peat remains from inside the 3” PVC well casing are then removed by means of

bailer;

• Drill on into underlying mineral subsoil layer by using window sampler method;

• Install minimum diameter 19mm piezometer down to maximum depth of hole;

• Install bentonite seal across the subsoil and peat interval to remove the

possibility of puncturing hole in any natural aquitard layer;

• Fill the remainder of the hole back to ground level with peat.

The above method was specifically designed to re-create a seal between the peat

and mineral subsoil layer after the installation of the piezometer. This removes any

potential for upwelling of mineral subsoil groundwater or downward movement of

peat water. The natural balance of water migration between the peat and subsoil will

not be altered as a result of the piezometer been present.

The proposed numbers of peat piezometers and subsoil piezometers are shown in

Table 1 below. The proposed locations are shown Figure 1.

The below numbers and locations may change depending on the Phase 1

investigation and ecological survey.

Table 1: Proposed numbers of installations

Installation

Type

No.

Shallow

peat

12

Deep peat 12

Subsoil 6

2.1.7 Topographical survey





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• Handheld dGPS rover staff; and,


Procedure

A topographic survey of the cSAC and surrounding area will be undertaken which will

include drains, water levels, intact bog and cutaway areas. The survey will be

undertaken in OSI national grid based on GPS static survey and to OSI GPS Datum

at Malin Head.

2.1.8 Sampling & on-going monitoring


• 1 no. HES site staff;

• Automatic water level loggers;

• Handheld water level dipper;

• YSI Multi-meter handheld hydrochemistry probe;

• 1 litre Sample bottles;

• Handheld purge device; and,


Procedure

Two rounds of peat water and groundwater sampling will be undertaken from

selected piezometer locations within the cSAC flush. Sampling will require visiting

each of the piezometer locations and purging less than 1 litre of groundwater / peat

water for removal off-site.

On-going groundwater level monitoring will need to be made as this will be a critical

element of the overall understanding of the cSAC flush. The monitoring will involve

visiting each of the piezometer locations within the cSAC to measure water levels.

Measurements will be undertaken using a handheld dipping device. It is proposed

that monthly water levels will be undertaken by HES or a trained Bord na Mona staff

member.

Automatic in well water level dataloggers are to be used where possible to reduce

the number of visits to the site. These are 22mm diameter and can be inserted into

each of the monitoring wells. These should be downloaded at least once every 6

months.



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2.2 Sites Identification

In accordance with the European Commission Methodological Guidance (EC2001), a

list of European sites that can be potentially affected by the project has been

compiled. While there are several European sites within a radius of 10 km of the iron

flush, the focused nature of the project will essentially affect only the iron flush.

However, for completeness the other European sites are listed

Bellacorick Iron Flush candidate Special Area of Conservation (code 0466)

This small site is within the Oweninny cutover bogs. It is a small minerotrophic fen

developed on glacial till overlying calcareous sandstone. The site supports several

rare and protected plant species, notably marsh saxifrage. (see below and Appendix

1 for full details)

Bellacorick Bog Complex candidate Special Area of Conservation (code 01922)

This is a large blanket bog site with some of the best examples of lowland blanket

bog in the country and a particularly well developed pool system. The site includes

the Knockmoyle Sheskin Nature Reserve.

Lough Dahybaun candidate Special Area of Conservation (code 02177)

This lake is a good example of an oligotrophic lake surrounded by blanket bog. It

supports the rare and protected plant Slender Naiad.

Owenduff/Nephin Complex candidate Special Area of Conservation (code 0534)

and Special Protection Area (code 04098)

This very large site extends from south-east of Bellacorick to include the entire

Nephin Beg range. It is an excellent example of a peatland landscape, with

extensive blanket bog and wet heath. The site is an important bird site, with

populations of the following Annex I species: Greenland White-fronted Geese, Merlin,

Peregrine and Golden Plover.

Taking into account the distance of the location of the works at the iron flush from the

Bellacorick Bog Complex SAC, the Lough Dahybaun SAC and the Owenduff/Nephin

Complex SAC/SPA, it can be concluded that the proposed works at the flush could

have no impacts on these sites and hence these are excluded from further

assessment.



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2.2.1 Bellacorick Iron Flush candidate Special Area of Conservation

Bellacorick Iron Flush is one of only eight recorded stations for the very rare species,

Marsh Saxifrage, in Ireland. All of these locations are within a 10 km radius of the

Iron Flush. The habitat in which it is found is typical for the species, though the

ground is drier than on other locations. This fen is surrounded by extensive areas of

commercially cut peat and drains that have caused a lowering of the water table,

resulting in the loss of vegetation associated with wetter areas that was described in

earlier references to the site by King and Scannell (1960). Some of the typical fen

species that were present are now absent or scarce (notably the rare mosses

Homalothecium nitens and Meesia triquetra) and the vegetation shows trends

towards drier, more acidic species. Without further studies, it is unknown if the

drying out of the flush and the lack of grazing will effect the survival of the species.

Despite this the flush is still considered of high conservation value for Marsh

Saxifrage.

SAC Qualifying Interests

The SAC has been selected for the following Annex II species:

• Marsh saxifrage (Saxifraga hirculus) [1528]

SAC Conservation Objectives

The NPWS Conservation Statement (2009) for the Bellacorick Iron Flush cSAC gives

the conservation objectives for the site as follows:

Objective 1: To maintain the Annex II species for which the cSAC has been selected

at favourable conservation status; Marsh Saxifrage

Objective 2: To maintain the extent, species richness and biodiversity of the entire

site

Objective 3: To establish effective liaison and co-operation with landowners, legal

users and relevant authorities.

2.3 Identification and Assessment of Potential Impacts on Bellacorick

Iron Flush cSAC

The method statement details all stages of required work for the proposed project.

Possible impacts on the conservation objectives for the SAC are considered in the

following, along with the measures which will be taken to alleviate or minimise any

such impacts.



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2.3.1 Impacts by personnel on site

The various stages of work will require incursions over the site to carry out surveys

and to reach investigation locations. Most of the stages will involve a single person

from HES accompanied by an ecologist, though the window sampling and

piezometer installation work will require two persons from HES. The initial

ecological survey will be carried out by a single ecologist. It is anticipated that the

ongoing monitoring will be carried out by a single HES person or by a trained Bord na

Mona staff member (route to be used will be pre-determined by the ecologist).

While incursions over sensitive wetland habitats are always undesirable, in this case

the incursions will be in a controlled setting and will be under the supervision of an

experienced wetland ecologist. The most sensitive habitat area, mainly the core

wet grassland where Marsh Saxifrage occurs, will be largely avoided.

Taking into account the temporary nature of the works and the controlled manner in

which they will be conducted, it is considered that the conservations objectives for

the SAC will not be adversely affected.

2.3.2 Impacts by intrusive works on site

The nature of the project requires various intrusive sampling for peat, subsoil and

ground water.

For the Phase 1 investigations it is expected that between no. 20-30 peat probes will

be undertaken and between no. 10-20 gouge core. The holes created by the peat

probe and gouge cores will only exist temporarily as the hole will collapse and reseal

itself.

For the Phase 2 investigations it is expected that there will be in the region of no. 12

shallow peat installations, no. 12 deep peat installations and no. 6 subsoil

installations (exact numbers are dependent on Phase 1 findings).

The method designed for the deep subsoil piezometers will re-create a seal between

the peat and mineral subsoil layer after the installation of the piezometer. This

removes any potential for upwelling of mineral subsoil groundwater or downward

movement of peat water. Therefore the natural balance of water migration between

the peat and subsoil will not be altered as a result of the piezometer been present.

As these proposed works are highly localised on site and will be carried out under

supervision so as to avoid areas where Marsh Saxifrage grows, and taking into

account that the natural water balance of the system will not be affected, it is



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considered that the conservations objectives for the SAC will not be adversely

affected.

2.4 Analysis of “In-combination” Effects

The Habitats Directive requires competent authorities to make an appropriate

assessment of any plan or project which is likely to have a significant effect alone or

in-combination with other plans and projects.

The following projects or landuses are considered in the context of possible in-

combination effects on the Bellacorick Iron Flush cSAC. It is noted that the main

landuse of the site is nature conservation, with the entire SAC being in the ownership

of An Taisce and NPWS.

Agriculture

The site would have formerly been grazed and nowadays low numbers of cattle and

sheep trespass onto the site. The Conservation Statement for the site considers

notes that undergrazing is a potential problem, as it can allow competing plant

species to dominate, leading to overall reduction in species richness.

Drainage

It is considered that the fen habitat has probably been drying out since 1950, with

many former species indicative of wet conditions now absent. The drainage has

occurred as a result of the commercial harvesting of the adjoining peat bogs.

Wind farms

A wind farm development has planning permission in the Oweninny cut bog areas

surrounding the fen. The NPWS Conservation Statement notes that this

development could have an impact on groundwater in the associated flush area, due

to deep excavation and pile-driving during construction and post-construction drying

out. It is noted further that a hydro-geological assessment of the wind farm site and

flush area, carried out before development takes place, could determine the quality,

quantity and sources of water feeding the SAC.

An existing wind farm built in 1992 occurs to the south-west of the fen, within a

distance of about 2.0 kilometres.



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In-combination effects conclusion

Nowadays, nature conservation is the only landuse associated with the Bellacorick

Iron Flush cSAC, with NPWS committed to scientific monitoring and site surveillance.

However, the site is considered to be still affected by drainage from past harvesting

of surrounding bogs and is likely to be in long-term hydrological decline.

The NPWS Conservation Statement for the site notes that the permitted wind farm

could have an impact on groundwater in the associated flush area, and that a hydro-

geological assessment of the wind farm site and flush area, carried out before

development takes place, could determine the quality, quantity and sources of water

feeding the SAC.

Due to the sensitive approach being adopted for the present project, especially the

close supervision by an ecologist throughout, it is considered that the proposal will

not adversely affect the conservation objectives of the SAC and hence would not

contribute to the principal adverse factor presently affecting the site, namely the long-

term effects of drainage. In fact, the project will contribute positively to the

understanding of the complex hydrology of the site.

2.5 Screening Conclusion and Statement

The screening process has examined the details of the proposed project and has

considered the conservation objectives of the relevant European site, namely the

Bellacorick Iron Flush cSAC.

It is concluded that the project, alone or in-combination with other projects or

landuses, will not have any direct or indirect impacts on the conservation objectives

of the cSAC. In fact, the findings from the project will contribute positively to the

understanding of the hydrology of the site, which is essential for its long-term

management. .

Accordingly, progression to Stage 2 of the Natura Impact Statement process is not

considered necessary.



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2.6 References

Department of Environment, Heritage & Local Government, Dublin. Conservation

Statement 2009 for Bellacorick Iron Flush cSAC. Site Code 466, Co. Mayo.

Department of the Environment, Heritage & Local Government (2011). Protected

sites in County Mayo - listings and maps. See www.npws.ie

European Commission (1996). Interpretation Manual of European Union Habitats.

Version Eur 15. European Commission, DG XI.

Fojt, W. (1988) Bellacorcik Iron Flush, Co Mayo. In: Mires Research Group. Field

Excursion, Ireland, 1988 (unpublished).

King, A.L.K. & Scannell, M.J.P. (1960) Notes on the vegetation of a mineral flush in

Co. Mayo. Irish Naturalists’ Journal 6: XIII.



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APPENDIX 1

SITE SYNOPSIS

SITE NAME: BELLACORICK IRON FLUSH

SITE CODE: 00466

The Bellacorick Iron Flush is situated about 7 km north-east of Bellacorick Co. Mayo,

on the headwaters of the Sruffaunnamuingabatia, a tributary of the Oweniny River.

The site contains a small minerotrophic fen developed on glacial till overlying

calcareous sandstone. The entire site is surrounded by drains and extensive areas of

mechanically-cut peat.

The Marsh Saxifrage (Saxifraga hirculus), a species protected under the Flora

Protection Order (1999) and listed on Annex II of the EU Habitats Directive, occurs in

the site. The rare mosses Homalothecium nitens and Meesia triquetra have also been

recorded from this site, although recent studies suggest that Meesia triquetra, at its

only recorded station in Britain and Ireland, appears to have become extinct. The

cause is thought to be the loss of suitable wet habitats through drainage.

Extensive areas of the site are now dominated by Purple Moor-grass (Molinia

caerulea), with Wild Angelica (Angelica sylvestris), Marsh Cinquefoil (Potentilla

palustris), Red Fescue (Festuca rubra), Yorkshire-fog (Holcus lanatus) and Marsh

Willowherb (Epilobium palustre) occurring. The Common Reed (Phragmites australis)

is found in wetter areas.

Typical blanket bog vegetation occurs in the non-flushed areas of the site, i.e. with

Purple Moor-grass, Black Bog-rush (Schoenus nigricans) and Hare’s-tail Cottongrass

(Eriophorum vaginatum). Rusty Willow (Salix cinerea subsp. oleifolia) occurs

throughout the site and in places supports a diverse community of lichens.

The continued survival of this habitat, and the species which occur there, is threatened

by the lack of grazing, the drainage and peat-cutting activities occurring around the

site, and the resultant development towards rank grassland and scrub. Bellacorick

Iron Flush is, nevertheless, of considerable interest, both in terms of the rich-flush

habitat, which is uncommon outside of the north Mayo region in Ireland, and because

of the presence of rare plant species.


APPENDIX B.

Ministers Approval for Iron Flush Study

Ballacorick Iron Flush Appendix 14b


APPENDIX C.

Section 21 Flora Licence

Ballacorick Iron Flush Appendix 14c


APPENDIX D.

VEGETATION STUDY

AS PART OF HYDRO-GEOLOGICAL INVESTIGATIONS

Ballacorick Iron Flush Appendix 14d

BELLACORICK IRON FLUSH VEGETATION STUDY

AS PART OF HYDRO-GEOLOGICAL INVESTIGATIONS

NOVEMBER 2012

Prepared for

ESB International

by

Biosphere Environmental Services

29 La Touche Park, Greystones, Co. Wicklow

Tel: 01-2875249 E-mail: [email protected]

Bellacorick Iron Flush Vegetation Study

BioSphere Environmental Services 2

Table of Contents

1. INTRODUCTION 3

2. HISTORY OF FLUSH DISCOVERY AND NOTABLE SURVEYS

CONDUCTED 6

3. METHODS 7

4. VEGETATION OF THE FLUSH 7

5. VEGETATION DESCRIPTIONS AT COUPLE LOCATIONS 14

6. FERMOYLE FLUSH 18

REFERENCES



1. Introduction

The blanket bog areas of north-west Mayo are known to contain a large number of flushes

which are influenced by upwelling base-rich water (Lockhart 1991). From a botanical

perspective these flushes are species-rich and support a range of plant species which are

otherwise absent from the surrounding ombrotrophic blanket bog. In the west of Ireland

blanket bog flushes are known to support populations of rare vascular plants such as

Saxifraga hirculus, Hammarbya paludosa and Eriophorum gracile (Lockhart 1991, Conaghan

1995). Blanket bog flushes also provide habitat for a suite of rare bryophyte species

(Lockhart, Hodgetts and Holyoak 2012).

Bellacorick Iron Flush is designated under the Habitats Directive as a Special Area of

Conservation (Site Code 000466). It is a small area of mineral-rich flush which is located

approximately 5 kilometres north-east of Bellacorick village in north-west Co. Mayo (Grid

reference G 006 246). The flush forms part of a nature reserve (in the ownership of An

Taisce and the National Parks and Wildlife Services) which comprises a remnant area of

blanket bog and flush habitat which is roughly triangular in shape (Figure 1). Much of the

land surrounding the nature reserve is now dominated by cutaway blanket bog and this tends

to consist of a mosaic of bare peat surface and re-colonizing areas which support plant

species such as soft rush (Juncus effusus), bulbous rush (Juncus bulbosus), common bog-

cotton (Eriophorum angustifolium) and the mosses Polytrichum commune and Campylopus

introflexus. The nature reserve is situated within the Bord na Móna Owenniny peat

harvesting area which extends to some fifty square kilometres. Peat harvesting operations

ceased in 2006 and a programme of bog rehabilitation is being undertaken by Bord na Móna.

The flush occurs at the bottom of a low hillock which has been largely stripped of peat cover

in recent decades. Since the late 1950’s extensive industrial-scale peat extraction has taken

place in areas immediately surrounding the iron flush and this has inevitably, over time,

resulted in the lowering of the water table within the flush. Lockhart et al. (2012) considered

that the disappearance from the flush of the rare moss Meesia tristicha (= Meesia triquetra)

shortly after its discovery there in 1958 was as a result of drying out of the flush habitat due

to peat extraction in the surrounding land

In terms of overall extent the flush measures approximately 250 metres in length by 80

metres in width and is oriented in a south-east to north-west direction. Water flows slowly in

a north-westerly direction and can often be seen trickling out from the cutaway peat bank

along the northern margins of the flush. The flush supports a species-rich flora which tends

to be dominated by a range of sedge and grass species which generally produce a sward of



between 30 and 50 cm in height (see Plate 1). Noteworthy plant species which occur in the

vegetation include the legally protected marsh saxifrage (Saxifraga hirculus) and the rare

calcicole moss Tomentypnum nitens. The western half of the nature reserve area is

dominated by typical ombrotrophic lowland blanket bog vegetation which contains a number

of large dystrophic bog pools (see Plate 2). Due to the presence of well-developed and

species-rich flush vegetation the site has been designated a Special Area of Conservation,

i.e. Bellacorick Iron Flush (IE0000466). In total, the remaining area of “intact” flush and bog

habitat occurring within the SAC boundary measures approximately 15 hectares.

As part of the environmental impact assessment for the Oweninny Wind Farm project a

hydro-geological investigation at the Bellacorick iron flush was required to determine the

potential for impact on the hydro-geology of the fen which could arise from the proposed

construction of wind turbine foundations in its vicinity. This hydro-geological assessment was

undertaken by Hydroenvironmental Services Ltd, a competent and qualified consultancy in

this field, and guided by Biosphere Environmental Services Ltd as requested by National

Parks and Wildlife Service. The assessment included a specialist habitat and vegetation

assessment input, which is described in the present report. The main aims of the habitat and

vegetation assessment work were:

(1) To describe the vegetation occurring within the nature reserve area, with a particular

regard to the mineral-rich, iron flush area.

(2) To liaise with the hydrological survey with a view to linking the observed hydrological

conditions with surface vegetation.

(3) To ensure that no significant disturbance occurs during the installation and ongoing

reading of hydrological instruments.



Figure 1. Aerial photograph, taken in the year 2000, which shows the outline of the nature reserve in red. Note the extensive surrounding cutaway blanket bog. The location of the core flush area is indicated by the blue arrow.

Plate 1. A general view of flush vegetation at Bellacorick.



Plate 2. To the west of the flush area there is an area of intact blanket bog with numerous large dystrophic pools/lakes.



2. History of flush discovery and notable surveys conducted

It appears that the iron flush area at Bellacorick was first noted in July 1957 by T.A. Barry

(Scannell, 1958). In late September of that year the rare moss Camptothecium nitens

(=Tomentypnum nitens) was identified from a parcel of collected mosses by A.L.K. King

(King, 1958b). This was only the second record of the species in Ireland, the first location

being Pollardstown fen, Co. Kildare where the species was collected and identified only a

couple of weeks previously in September 1957. Prior to that, Tomentypnum nitens had only

been recorded in Ireland from fossil remains found in peat cores.

Later in 1958 the rare moss species Meesia tristicha (= Meesia triquetra) was recorded from

moss material collected at Bellacorick (King, 1958a). This was the first record of the species

growing in Ireland and Britain, although it had been identified in post-glacial peat remains in

Britain previously. It would appear that Meesia triquetra disappeared from the site not long

after its discovery as a result of drying out of the flush habitat due to peat extraction in the

surrounding land (Lockhart et al., 2012). The species would now appear to be extinct at this

site.

In October 1957 Bellacorick flush was visited by T.A. Barry, A.L.K. King and M.J.P. Scannell

(Scannell, 1958). On that visit the presence of Saxifraga hirculus was noted growing along

with lesser spearwort (Ranunculus flammula), marsh arrow-grass (Triglochin palustris), bog

bean (Menyanthes trifoliata), common reed (Phragmites australis) and wild angelica

(Angelica sylvestris). Saxifraga hirculus was noted growing over an area of about 25 square

yards and King (1958b) notes that Saxifraga hirculus and Tomentypnum nitens did not

appear to co-occur. Due to its extreme rarity in Ireland Saxifraga hirculus is a legally

protected species nationally under the 1999 Flora Protection Order (S.I. 94 of 1999).

King and Scannell produced one further paper on the vegetation of Bellacorick flush (King

and Scannell, 1960). This paper listed plant species which grew in association with the rare

species Tomentypnum nitens, Meesia triquetra and Saxifraga hirculus. Tomentypnum nitens

was described as being found “in all parts of the undisturbed area”, however at present the

species appears to be much less frequent at the site.

Since its initial discovery Bellacorick iron flush has been visited and surveyed by various

researchers. Some of the more important recent surveys have been carried out by Dr. Neil

Lockhart in the early to mid-1980’s and Dr. Caoimhe Muldoon in the late 2000’s. Lockhart

visited Bellacorick flush as part of a wider study of flush and fen habitats/vegetation in Co’s



Mayo and Galway for a Ph.D. Thesis (Lockhart 1991). In a paper which outlined the

occurrence of Homalothecium nitens (=Tomentypnum nitens) in the north-west Mayo area

Lockhart (1987) presented two relevés (i.e. a list of plants in a delimited plot of vegetation

with information on species cover and substrate) from Bellacorick flush in order to describe

the associated vegetation of the species. In 1989 details were published of new localities for

Saxifraga hirculus in Ireland and as part of this paper he also presented two relevés from

Bellacorick flush which describe the associated vegetation of the species (Lockhart 1989).

In 2009 Bellacorick flush was visited by Caoimhe Muldoon as part of a PhD study of the

ecology and conservation of Saxifraga hirculus in Ireland. During her visit she mapped the

distribution of the species within the flush, recorded the vegetation in which the species

grows and assessed the conservation status of the species at Bellacorick.

3. Methods

The site was visited and surveyed by Dr John Conaghan on the 10th, 11th and 12th of

September 2012. A general botanical survey of the flush area was conducted with particular

attention paid to identifying suitable locations for groups of piezometers (required for the

hydrogeological study of the iron flush and often referred to as couples) and proposed

access (walking) routes to these couples to prevent impact on protected and rare species.

The locations of the rare plant species Saxifraga hirculus and Tomentypnum nitens were

noted using a Garmin GPS 12 and these locations were subsequently plotted on maps

(Figure 2). Vascular plant species nomenclature in this report follows Stace (2010) while the

nomenclature of mosses follows Smith (2004).

4. Vegetation of the flush

At present the vegetation at Bellacorick flush is dominated by a diverse range of grasses and

sedges with the most conspicuous species including bottle sedge (Carex rostrata), Yorkshire

fog (Holcus lanatus), marsh cinquefoil (Potentilla palustris), creeping bent (Agrostis

stolonifera), ragged Robin (Lychnis flos-cuculi), wild angelica (Angelica sylvestris) and purple

moor-grass (Molinia caerulea). There are occasional low shrubs of willow (Salix sp.), mostly

along the flush margins, however these do not form extensive areas of scrub. The moss

layer is typically well-developed and luxuriant with Scleropodium purum, Rhytidiadelphus

squarrosus, Aulocomium palustris and a range of Sphagnum species generally dominating.

In terms of ecological preferences the majority of the plant species growing within the flush



indicate that habitat conditions are at least moderately base-enriched. Comparing the

vegetation to the habitats outlined in Fossitt (2000) it would appear that the “core” flush

vegetation is, on balance, best accommodated in the poor fen and flush (PF2) category as it

tends to lack species such as black bog rush (Schoenus nigricans) and long-stalked yellow

sedge (Carex viridula subsp. Brachyrrhyncha) which are characteristic of rich fen. It must be

noted however that there are some similarities to the closely related habitat categories rich

fen and flush (PF1) and transition mire and quaking bog (PF3). This observation simply

reflects the fact there is often not a clear demarcation between different flush types in the

field.

The core flush area (see Figure 2) is largely surrounded by a zone of blanket bog vegetation

(c. 50 to 100 metres wide) in which purple moor-grass is prominent. This high cover of

purple moor-grass in what is, by and large, bog vegetation indicates that there is some

influence of water flow/mineral enrichment in the zone where flush and bog vegetation meet.

Along the eastern edge of the flush there is an area of species-poor vegetation which is

overwhelmingly dominated by purple moor-grass with conspicuous common reed

(Phragmites australis) (see Plate 5). This vegetation type is probably linked with a strongly

fluctuating water table and/or mineral enrichment. Table 1 presents a list of plant species

recorded at the site during the present survey and also compares the vegetation composition

as recorded by Lockhart in the 1980’s.

Table 1. List of plant species recorded growing within Bellacorick flush in the present survey

(September 2012) with a comparison to earlier work by Lockhart (1987,1989).

Plant Species

Recorded by Lockhart

(1987, 1989)

Recorded in this

survey Agrostis canina ✓ ✓

Agrostis stolonifera ✓ ✓

Angelica sylvestris ✓ ✓

Anthoxanthum odoratum ✓ ✓

Aulocomium palustris ✓ ✓

Brachythecium rutabulum ✓ ✓

Calliergonella cuspidata ✓ ✓

Calluna vulgaris ✓ ✓

Caltha palustris ✓ ✓

Calypogeia muellerana ✓ ✓

Cardamine pratensis ✓ ✓

Carex diandra ✓ ✓

Carex echinata ✓ ✓

Carex panicea ✓ ✓

Carex rostrata ✓ ✓

Dicranum scoparium ✓ ✓



Plant Species


(1987, 1989)

Recorded in this

survey

Epilobium palustre ✓ ✓

Erica tetralix ✓ ✓

Eriophorum angustifolium ✓ ✓

Galium palustre ✓ ✓

Holcus lanatus ✓ ✓

Homalothecium nitens ✓ ✓

Hylocomium splendens ✓ ✓

Juncus articulatus ✓ ✓

Lophocolea bidentata ✓ ✓

Luzula multiflora ✓ ✓

Lychnis flos-cuculi ✓ ✓

Menyanthes trifoliata ✓ ✓

Molinia caerulea ✓ ✓

Narthecium ossifragum ✓ ✓

Peltigera membranacea ✓ ✓

Phragmites australis ✓ ✓

Pleurozium schreberi ✓ ✓

Polygala serpyllifolia ✓ ✓

Potamogeton polygonifolius ✓ ✓

Potentilla erecta ✓ ✓

Potentilla palustris ✓ ✓

Rumex acetosa ✓ ✓

Saxifraga hirculus ✓ ✓

Scleropodium purum ✓ ✓

Sphagnum capillifolium ✓ ✓

Succisa pratensis ✓ ✓

Vaccinium oxycoccus ✓ ✓

Viola palustris ✓ ✓

Rhytidiadelphus squarrosus ✓ ✓

Sphagnum subnitens ✓ ✓

Carex dioica ✓

Cerastium fontanum ✓

Eleocharis palustris ✓

Eurhynchium praelongum ✓

Festuca rubra ✓

Leontodon autumnalis ✓

Plantago lanceolata ✓

Rhizomnium punctatum ✓

Sphagnum auriculatum ✓

Sphagnum recurvum ✓

Sphagnum teres ✓

Carex limosa ✓

Carex nigra ✓



Plant Species


(1987, 1989)

Recorded in this

survey

Carex paniculata ✓

Cladium mariscus ✓

Equisetum palustre ✓

Galium saxatile ✓

Hypnum jutlandicum ✓

Juncus bulbosus ✓

Juncus effusus ✓

Melampyrum pratense ✓

Myrica gale ✓

Osmunda regalis ✓

Salix aurita ✓

Sphagnum palustre ✓

Triglochin palustris ✓

Utricularia intermedia ✓

Valeriana officinalis ✓

The majority of the marsh saxifrage (Saxifraga hirculus) population seen within the flush was

growing in an area measuring approximately 20 metres by 10 metres in extent, along the

western margins of the flush (see Plates 3 & 4). The extent of the population is illustrated in

Figure 2. Table 2 outlines the GPS grid references at which the species was noted. It

should be noted that marsh saxifrage is probably more widespread than the survey suggests

as it can be difficult to identify non-flowering plants, especially when they occur scattered

through tall wetland vegetation. However, there can be little doubt that the area identified

comprises the core area of the species distribution within the site. Approximately 40

flowering heads of marsh saxifrage were noted during the present survey (mid-September),

which is much less than the 1,000+ flowering heads noted by Muldoon in 2009.



Table 2. Grid references for marsh saxifrage plants at Bellacorick flush, September 2012.

GPS reading

G 00597 24710

G 00596 24709

G 00600 24711

G 00604 24715

G 00606 24715

G 00599 24726

G 00597 24726

G 00599 24722

G 00598 24723

G 00607 24705

G 00601 24705

G 00596 24705

G 00591 24730

G 00631 24717

The nationally vulnerable moss Tomentypnum nitens was recorded growing sparingly in flush

vegetation to the north-west of the marsh saxifrage population. It was observed growing at

two locations where the slow trickling of iron-stained surface water across the peat surface

occurs. Table 3 outlines the GPS grid references of the species at Bellacorick.

Table 3. Grid references for Tomentypnum nitens plants at Bellacorick flush, September

2012.

GPS reading

G 00571 24759

G 00586 24745



Plate 3. A close-up view of marsh saxifrage (Saxifraga hirculus) in flower at Bellacorick flush.

Plate 4. Flowering heads of marsh saxifrage visible in tall, sedge-dominated vegetation.



Plate 5. Along the eastern margins of the flush the vegetation is dominated by purple moor grass with common reed also conspicuous.

Plate 6. A view of piezometers installed at the northern edge of the flush.



5. Vegetation associated with couple locations

In order to assess the existing hydrological conditions at the flush a number of groups of

piezometers (subsequently referred to as couples) were installed in mid-September 2012 by

Hydro-Environmental Services. During installation the hydrological team was accompanied

by John Conaghan in order to ensure that sensitive areas of the flush were avoided and that

tracking damage to vegetation was minimized. Prior to this work commencing, the flush area

had been surveyed in order to identify the distribution of marsh saxifrage and the moss

Tomentypnum nitens (as described). Work was then planned and executed in such a way

that couple locations and associated access routes avoided areas in which these important

species grow.

Figure 2. Map showing the vegetation/habitat cover at Bellacorick flush and the location of couples.

Immediately prior to piezometer installation the vegetation composition at the couple

locations was described (see Figure 2 for couple locations). In the following pages the

vegetation composition at these locations is outlined in terms of the dominant plant species

and the main associated plant species growing within a 2 metre radius of the couple location.

In addition, the pH and conductivity readings of associated surface waters recorded by

Hydro-Environmental Services in the mid-September 2012 are also presented in order to



give an indication of the degree of groundwater influence. See associated report by Hydro-

Environmental Services for more complete hydrochemistry results.

Couple C1 – GPS G 00625 24547

Dominant plant species = Molinia caerulea (90% cover)

Associated plant species = Potentilla palustris, Succisa pratensis, Myrica gale, Potentilla

erecta, Valeriana officinalis, Hylocomium splendens, Carex echinata, Angelica sylvestris,

Juncus effusus.

The dominance of Molinia caerulea at this point suggests the presence of a fluctuating water

table.

No surface water analyses available

Couple C2 – GPS G 00631 24692

Dominant plant species = Carex rostrata and Potentilla palustris (Combined cover 50 to 80%

cover).

Associated plant species = Holcus lanatus, Lychnis flos-cuculi, Agrostis capillaris,

Anthoxanthum odoratum, Angelica sylvestris, Molinia caerulea, Rhytidiadelphus squarrosus,

Aulocomium palustris, Carex diandra, Rumex acetosa, Phragmites australis, Cardamine

pratensis, Scleropodium purum.

This couple is located close to the centre of the flush and is typical of the “core” flush

vegetation generally.

Surface water pH = 6.8, Surface water conductivity = 500 µs/cm

Surface waters at this point would indicate a strong influence of mineral enrichment.

Couple C3 – GPS G 00673 24643

Dominant plant species = Carex nigra (50 to 75% cover).

Associated plant species = Agrostis capillaris, Anthoxanthum odoratum, Rumex acetosa,

Holcus lanatus, Scleropodium purum, Potentilla palustris, Viola palustris, Hylocomium

splendens, Vaccinium oxycoccus. Occasional clumps of Juncus effusus occur within 20

metres.

This couple is located at the south-eastern end of the flush


Surface waters at this point would indicate a moderate influence of mineral enrichment.

Couple C4 – GPS G 00726 24582

Dominant plant species = Molinia caerulea and Sphagnum capillifolium

Associated plant species = Succisa pratensis, Calluna vulgaris, Myrica gale, Erica tetralix,

Narthecium ossifragum, Polygala serpyllifolia, Carex panicea, Trichophorum cespitosum,



Cladonia portentosa, Sphagnum papillosum, Cladonia uncialis, Hypnum jutlandicum,

Racomitrium lanuginosum, Eriophorum angustifolium and Potentilla erecta. Sphagnum

cover is generally between 40 and 60%.


Surface waters at this point would indicate a low influence of mineral enrichment.

Couple C6 – GPS G 00692 24709

Dominant plant species = Molinia caerulea (70 to 90% cover)

Associated plant species = Anthoxanthum odoratum, Potentilla erecta, Rumex acetosa,

Holcus lanatus, Hypnum jutlandicum, Potentilla palustris, Agrostis capillaris, Hylocomium

splendens, Carex echinata, Angelica sylvestris, Juncus effusus, Phragmites australis, Galium

saxatile.

Couple located at the bottom of a break in slope.



Couple C6a – GPS G 00670 24738

Dominant plant species = Molinia caerulea (80 to 90% cover) with conspicuous Phagmites

australis.

Associated plant species = Anthoxanthum odoratum, Succisa pratensis, Potentilla erecta,

Juncus bulbosus, Hypnum jutlandicum, Calluna vulgaris, Agrostis sp. Myrica gale, Potentilla

erecta, Hylocomium splendens, Carex echinata, Angelica sylvestris, Juncus effusus.


Surface waters at this point would indicate a strong influence of mineral enrichment.

Couple C9 – GPS G 00566 24683

Dominant plant species = Molinia caerulea

Associated plant species = Myrica gale, Calluna vulgaris, Succisa pratensis, Carex echinata,

Erica tetralix, Narthecium ossifragum, Menyanthes trifoliata, Eriophorum angustifolium,

Hylocomium splendens and Potentilla erecta.

The vegetation comprises very wet and quaking flushed bog vegetation along the western

margins of the flush area.



Couple C10 – GPS G 00444 24658

Dominant plant species = Molinia caerulea and Calluna vulgaris



Associated plant species = Sphagnum capillifolium, Carex panicea, Schoenus nigricans,

Erica tetralix, Narthecium ossifragum, Trichophorum cespitosum, Cladonia portentosa,

Sphagnum papillosum, Cladonia uncialis, Drosera rotundifolia, and Potentilla erecta.

Sphagnum cover is generally between 40 and 60%.

The vegetation is dominated by typical blanket bog species.

No surface water analyses available

From the initial observations it would appear that the surface waters associated with the

“core” flush vegetation have a higher pH and conductivity than in the surrounding

ombrotrophic blanket bog areas, which are predominantly rain-fed. Ongoing analysis of

water chemistry will further elucidate the linkages between hydrochemistry, water levels and

vegetation.

6. Formoyle Flush

As part of the investigations into the Bellacorick iron flush, NPWS had indicated that

consideration should be given to the flushes to the east of the Oweninny site boundary

(known as Formoyle flush) to ensure that the project would not have any indirect hydrological

impacts on this sensitive area.

Formoyle flush is an extensive area of base-rich fen/flush which is located approximately 4

km north of Eskeragh church in north-west Co. Mayo. The land immediately surrounding the

flush is dominated by intact lowland blanket bog/heath. Further away from the core flush

area there is an extensive area of previously afforested bog to the east and an area of Bord

na Mona industrial cutaway blanket bog to the west.

The flush is generally very wet with many areas dominated by quaking raft of fen vegetation.

A number of narrow flushed channels flow into the main body of the flush from higher ground

to the north and the west. The vegetation at Formoyle flush is generally dominated by black

bog rush (Schoenus nigricans) with common reed (Phragmites australis) also conspicuous.

Other frequent plant species in the vegetation include bog bean (Menyanthes trifoliata), bog

pondweed (Potamogeton polygonifolius), bottle sedge (Carex rostrata) and the moss

Campylium stellatum. In recent decades a number of rare bryophyte species have been

recorded here (Neil Lockhart personal communication).

Whilst it is difficult to accurately assess the extent of the flush habitat at Formoyle there is

little doubt that the flush area at Formoyle is much more extensive than the flush surrounded

by cutaway bog at Bellacorick. The vegetation at Formoyle tends to be dominated by



Schoenus nigricans, Menyanthes trifoliata and Phragmites australis, whilst the vegetation of

Bellacorick flush tends to be dominated by sedges (Carex sp.) and mosses such as

Hylocomium splendens. Preliminary observations would also suggest that the flush habitat

at Formoyle is much wetter and the peat is much more quaking than at Bellacorick.

The flush area at Formoyle was visited on 28th September 2012 by John Conaghan and

David Broderick. In view of the very fragile nature of the flush habitat and vegetation at

Formoyle the flush habitat was not traversed. The western margins of the flush were walked

and GPS co-ordinates of the westernmost margins of the flush were noted. A number of

water samples were collected for analysis (by Hydro-Environmental Services) from the

western margins of the flush.



References Conaghan, J. (1995). The ecology of Eriophorum gracile and Eriophorum latifolium in Ireland.

Unpublished PhD. Thesis, National University of Ireland, Galway. Fossitt, J. A. (2000). A guide to habitats in Ireland. The Heritage Council, Ireland. King, A.L.K. (1958a). Meesia tristicha Bruch & Schimp. in Ireland. Irish Naturalists’ Journal.

12: 347. King, A.L.K. (1958b). Camptothecium nitens (Hedw.) Schp. in Ireland. Irish Naturalists’

Journal. 12: 332. King, A.L.K. and Scannell (1960). Notes on the vegetation of a mineral flush in Co. Mayo.

Irish Naturalists’ Journal. 13: 137-14. Lockhart, N.D. (1987). The occurrence of Homalothecium nitens (Hedw.) Robins. in Ireland.

Journal of Bryology 14: 511-517. Lockhart, N.D. (1989). Three new localities for Saxifraga hirculus L. in Ireland. Irish

Naturalists’ Journal. 23: 65-69. Lockhart, N.D. (1991). Phytosociological and ecological studies of lowland blanket bog

flushes in west Galway and north Mayo. Unpublished PhD. Thesis, National University of Ireland, Galway.

Lockhart, N.D., Hodgetts, N. and Holyoak, D. (2012). Rare and threatened bryophytes of

Ireland. National Museums Northern Ireland, Holywood, Co. Down. Muldoon, C.S (2011). Conservation biology of Saxifraga hirculus L. in Ireland. Unpublished

PhD. Thesis, University of Dublin, Trinity College. Scannell, M.J.P. (1958). Saxifraga hirculus in Co. Mayo. Irish Naturalists’ Journal. 12, 248. Smith, A.J.E. (2004). The Moss Flora of Britain and Ireland (2nd edition). University Press,

Cambridge. Stace, C. (2010). New Flora of the British Isles (3rd edition). University Press, Cambridge.

Couple Lithology Von Post

C1

0 - 0.12 Wet fibrous peat with vegetation roots H2/H3

0.12-0.9 Black soft PEAT with some visible vegetation fibres H6/H7

0.9-1.7 Black and orange (interbedded colouring) soft PEAT H6/H7

1.7-3.26

dark brown/black soft PEAT with some visible vegetation fibres (more

fen type peat) H4/H5

3.26-3.31 Soft yellow slightly sandly CLAY (precipitate)

3.31-3.51 Coarse grey SAND

3.51-4.24

Soft to Firm, grey, damp, slightly silty fine SAND with very occassional

gravel clasts.

C2


0.15-2.0 Soft, brown PEAT, with some visible vegetation fibres H4/H5

2.0-2.86 Soft, wet, black PEAT H5/H6

2.86-2.90 Loose, coarse grey SAND

2.90-3.3 Soft, grey/black, damp SILT/CALY with occassional pebbles

3.3-4.0

Medium dense to firm, grey, damp fine SAND, with very occassional

gravel clasts at depth (dead sand, not very permeable).

C3


0.2-2.74

Soft, brown, wet PEAT, with some visible vegetation fibres reducing

with depth H5/H7

C4


0.1-2.45 Soft, light brown, wet fibrous PEAT H3/H4

decreasing fibre content with depth H5/H7

red wood remains @ 2.1mbgl

2.88-2.45 black soft PEAT H6/H7

2.88-2.98 grey wet fine silty SAND (dilatent)

C6


0.2-0.9 Soft, brown, dryish/damp PEAT, with some visible vegetation fibres H6/H7

0.9-1.1

Loose, brown, coarse SAND with occ. Peat roots and very occc.

Shell fragments and rounded pebbles

1.1-2.35

Medium dense, grey damp SAND, with occ. Gravel clasts (likley low

permeability, dead sand)

2.35-2.55 Dense, grey sandy GRAVEL

2.55-3.45 Soft grey slightly clayey, sandy SILT with occ. angular Gravel clasts

C6A


0.2-0.91

Soft, brown, dryish/damp PEAT, with some visible vegetation fibres

throughout H5/H6

0.91-2.5

grey fine silty SAND (dead sand), with occ. Gravel clasts, with very

solft wet layer between 2.5 - 3.6mbgl

2.5-3.6

firm to stiff grey/redish, fine silty SAND with very occ. Clay and gravel

clasts

3.6-4.0 Grey coarse SAND with occ. Gravel clasts

4.0-4.24 firm blue/grey dense silty SAND with occ. Fine medium gravel clasts

C7

0 - 0.20 Light brown, poorly humified fibrous PEAT H2/H3

0.2-1.0

Light brown, poorly humified PEAT with visible fine white vegetation

fibres H4/H5

C8

0 - 0.20 Light brown, poorly humified fibrous PEAT H2/H3

0.2-1.41

Light brown, damp, poorly humified PEAT with visible fine white

vegetation fibres H4/H5

>1.41 gravelly/sandy feel to mineral soil below peat

C9

0-1 no recovery

1.0-2.0 very soft wet fibrous PEAT H4/H5

2.0-3.0 very wet soft dark brown PEAT with occ. phragmities remains H5/H6

3.0-4.10 dark brown to black very wet, very soft PEAT H6

>4.1 SAND at base @4.10mbg;

C10

0-0.2 very soft wet fibrous PEAT

0.2-2.95 very wet soft dark brown PEAT with occ. phragmities remains

>2.95 SAND at base @2.95mbg;

90.0

90.5

91.0

91.5

92.0

92.5

93.0

93.5

08/09/2012 28/09/2012 18/10/2012 07/11/2012 27/11/2012

m O

D

Date

Bellacorick - Couple C1

C1-P1

C1-P2

C1-PH1

95.2

95.4

95.6

95.8

m O

D


C2-P1

94.4

94.6

94.8

95.0

08/09/2012 28/09/2012 18/10/2012 07/11/2012 27/11/2012

m O

D

Date

C2-P1

C2-P2

C2-PH1

93.5

94.0

94.5

95.0

95.5

96.0

96.5

97.0

08/09/2012 28/09/2012 18/10/2012 07/11/2012 27/11/2012

m O

D

Date


C3-P1

C3-P2

C3-PH1

94.0

94.5

95.0

95.5

96.0

96.5

97.0

97.5

08/09/2012 28/09/2012 18/10/2012 07/11/2012 27/11/2012

m O

D

Date


C4-P1

C4-PH1

96.096.597.0


93.093.594.094.595.095.596.0

08/09/2012 28/09/2012 18/10/2012 07/11/2012 27/11/2012

m O

D

Date

C6-P1

C6-P2

C6-PH1

92.50

93.00

93.50

94.00

94.50

95.00

95.50

96.00

08/09/2012 28/09/2012 18/10/2012 07/11/2012 27/11/2012

m O

D

Date

Bellacorick - Couple C6A

C6A-P1

C6A-P2

C6A-PH1

94.70

94.75

94.80

94.85

94.90

94.95

29/08/2012 23/09/2012 18/10/2012 12/11/2012

m O

D

Date


C9-P1

C9-PH1

93.5

94.0

94.5


91.5

92.0

92.5

93.0

93.5

08/09/2012 28/09/2012 18/10/2012 07/11/2012 27/11/2012

m O

D

Date

C10-PH1

C10-P1

Bellacorick Iron Flush P1196

90.0

90.5

91.0

91.5

92.0

92.5

93.0

93.5

29/08/2012 18/10/2012 07/12/2012 26/01/2013 17/03/2013

m O

D

Date


C1-P1

C1-P2

C1-PH1

95.2

95.4

95.6

95.8

m O

D


Appendix II

94.4

94.6

94.8

95.0

95.2

29/08/2012 18/10/2012 07/12/2012 26/01/2013 17/03/2013

m O

D

Date

C2-P1

C2-P2

C2-PH1

93.5

94.0

94.5

95.0

95.5

96.0

96.5

97.0

29/08/2012 18/10/2012 07/12/2012 26/01/2013 17/03/2013

m O

D

Date


C3-P1

C3-P2

C3-PH1

Appendix II


94.0

94.5

95.0

95.5

96.0

96.5

97.0

97.5

29/08/2012 18/10/2012 07/12/2012 26/01/2013 17/03/2013

m O

D

Date


C4-P1

C4-PH1

97.0


Appendix II

93.093.594.094.595.095.596.096.597.0

29/08/2012 18/10/2012 07/12/2012 26/01/2013 17/03/2013

m O

D

Date

C6-P1

C6-P2

C6-PH1

92.50

93.00

93.50

94.00

94.50

95.00

95.50

96.00

29/08/2012 18/10/2012 07/12/2012 26/01/2013 17/03/2013

m O

D

Date

Bellacorick - Couple C6A

C6A-P1

C6A-P2

C6A-PH1

Appendix II


94.70

94.75

94.80

94.85

94.90

94.95

95.00

29/08/2012 18/10/2012 07/12/2012 26/01/2013 17/03/2013

m O

D

Date


C9-P1

C9-PH1

93.5

94.0

94.5


Appendix II

91.5

92.0

92.5

93.0

93.5

29/08/2012 18/10/2012 07/12/2012 26/01/2013 17/03/2013

m O

D

Date

C10-PH1

C10-P1

Appendix II

Table 1: Recharge coefficients for different hydrogeological settings.

Recharge coefficient (rc) Vulnerability category Hydrogeological setting

Min (%) Inner Range Max (%)* 1.i Areas where rock is at ground surface 60 80-90 100 1.ii Sand/gravel overlain by ‘well drained’ soil 60 80-90 100

Sand/gravel overlain by ‘poorly drained’ (gley) soil 1.iii Till overlain by ‘well drained’ soil 45 50-70 80 1.iv Till overlain by ‘poorly drained’ (gley) soil 15 25-40 50 1.v Sand/ gravel aquifer where the water table is ≤ 3 m below surface 70 80-90 100

Extreme

1.vi Peat 15 25-40 502.i Sand/gravel aquifer, overlain by ‘well drained’ soil 60 80-90 100 2.ii High permeability subsoil (sand/gravel) overlain by ‘well drained’ soil 60 80-90 100 2.iii High permeability subsoil (sand/gravel) overlain by ‘poorly drained’ soil 2.iv Moderate permeability subsoil overlain by ‘well drained’ soil 35 50-70 80 2.v Moderate permeability subsoil overlain by ‘poorly drained’ (gley) soil 15 25-40 50 2.vi Low permeability subsoil 10 23-30 40

High

2.vii Peat 0 5-15 203.i Moderate permeability subsoil and overlain by ‘well drained’soil 25 30-40 60 3.ii Moderate permeability subsoil and overlain by ‘poorly drained’ (gley) soil 10 20-40 50 3.iii Low permeability subsoil 5 10-20 30

Moderate

3. iv Basin peat 0 3-5 10 4.i Low permeability subsoil 2 5-15 20Low 4.ii Basin peat 0 3-5 105.i High Permeability Subsoils (Sand & Gravels) 60 85 100 5.ii Moderate Permeability Subsoil overlain by well drained soils 25 50 80 5.iii Moderate Permeability Subsoils overlain by poorly drained soils 10 30 50 5.iv Low Permeability Subsoil 2 20 40

High to Low

5.v Peat 0 5 20Acknowledgement: many of the recharge coefficients in this table are based largely on a paper submitted by Fitzsimons and Misstear (in press).

page 6 of 23

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