Annex IV protected areas: water dependent habitats and species and high status sites




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4.2. Databases circulated by the Western RBD

The following national databases have been developed by the Western RBD in consultation with NPWS, for the use of agencies involved in implementing the Water Framework Directive, and are circulated with this report:

1. SAC_Water_Dependency: GIS SAC map layer, and database listing of all Habitats Directive Annex 1 listed coastal and onshore water dependent habitats, and Annex 2 listed species presence, and presence as a Qualifying Interest, within the SAC network. This database uses the NPWS Habitats Assignment Database dated February 8th 2008, updated with the most recently available information from the Article 17 assessment databases and backing documentation for the following species: Hamatocaulis (Drepanocladus) vernicosus, Najas flexilis, Saxifraga hirculus, Vertigo angustior, Vertigo geyeri, Vertigo moulinsiana, and Margaritifera margaritifera, in consultation with NPWS. The database map layer uses the SAC update notified by NPWS on 4th September 2008.
The SAC_ Water_ Dependency database updates the Register of Protected Areas for the SAC component of the Natura 2000 network, via the logical field WD_H_S = “T”

It should be noted that the boundaries of existing conservation sites are subject to revision, and that additional sites are likely to be proposed for designation under EU and/or national legislation. The map layer provided with the SAC water dependency database should therefore be cross-checked against the most recent GIS releases of SACs by NPWS, both visually and with reference to the boundary version data provided in the browser. It should also be noted that Habitats Directive Annex 1 listed habitats and Annex 2 listed species are subject to on-going survey by NPWS, and the Qualifying Interests listed for individual SACs are revised from time to time, as well as the habitats and species that are present in the SAC as non-qualifying interests.

The definition table for the SAC water dependency database is given in Appendix 4.

2. NPWS databases, linked to EPA water body codes by the Western RBD, with site-specific conservation status assessments:



  • Coastal lagoons (priority Annex 1 listed habitat)

  • Najas flexilis (Annex 2 listed plant species of lakes)

3. Arctic char lakes, linked to EPA lake water body codes by the Western RBD, with notes on current pressures, as a fish species requiring high water quality and vulnerable to water abstraction impacts: data provided by the Irish Char Conservation Group.

5. WATER STATUS SENSITIVITY OF WATER DEPENDENT HABITATS AND SPECIES.


This Section considers the sensitivity of Habitats Directive Annex 1 and 2 listed water dependent habitats and species to water status management issues that arise under the Water Framework Directive. Ideally, it would be possible to set detailed targets and environmental quality standards for individual catchments on the basis of the most sensitive water dependent habitat and species receptors present, taking hydrological and water quality requirements into account. At present, however, there is not enough spatial information available to allow this to be done for all protected water dependent habitats and species.


The two Habitats Directive Annex 2 listed fresh water pearl mussel species Margaritifera have been identified as particularly sensitive to water status, and all Irish populations are at unfavourable conservation status and require WFD remedial measures under the Habitats Directive. Margaritifera margaritifera and Margaritifera durrovensis will be subject to sub-basin plans under the Water Framework Directive, which will apply to the sole remaining population of M. durrovensis and to 27 Qualifying populations of M. margaritifera. Detailed GIS databases are being prepared for these populations, which will be used in monitoring and audit of the measures which will be applied to them.

Target water quality and habitat attributes for the two fresh water pearl mussel Margaritifera species are included in the backing documentation for the conservation status assessments for these species. Following further consideration by NPWS, objectives for Margaritifera have been published as a Consultation Paper and Draft European Communities Environmental Objectives (Freshwater Pearl Mussel) Regulations by the Minister for the Environment, Heritage and Local Government (December 2008). Following a public consultation phase, and consideration of comments made, the Regulations are expected to be finalised and come into operation in early 2009. The sub-basin plans referred to above will be set up under these Regulations.

There are a number of M. margaritifera populations which are not currently listed as Qualifying populations, but which are nevertheless covered by the legal provisions of the Habitats Directive, and the Wildlife Acts nationally. Survey of these populations is on-going to determine their full extent and status. Listings of the Qualifying and other populations are given in Appendix 7 of this guidance.
With regard to Annex 1 listed water dependent habitats and Annex 2 listed species, a draft report on ecological requirements has been prepared by the North-South Share Project for a total of 18 water dependent habitats and 9 species (Curtis, Downes and Ní Chatháin, 2006), with notes on an additional 4 species. The main difficulty encountered by the authors in compiling the report was the lack of accurate data on physico-chemical water status parameters for conservation sites where the different habitats and species occur within the North-South Share Project area. Most of the available data referred to sites elsewhere in Ireland, and in some cases relevant data is only available from studies carried out within Great Britain. Another difficulty was to determine the precise location from which water or other samples were collected; for example some individual SACs include a very large number of lakes, fens or turloughs, and the annual range of water quality parameters for one of these can not necessarily be assumed to be relevant to another one.
There is a related risk that existing water quality data for a particular water body which is recognised as an Annex 1 listed lake habitat, for example, may be representative of a lake that is not at favourable conservation status under the Habitats Directive; such data should not be used to set Habitats Directive environmental quality standards for that particular lake or for others of the same habitat type. Clearly much work is required to co-ordinate studies and surveys carried out by different agencies so that appropriate data are collected and considered as to their applicability, as measures under the Water Framework Directive are implemented, monitored and audited, and adjusted as Programmes of Measures progress towards the second cycle. Measures intended to address these issues are included in Section 7 of this guidance.
An interim approach.

As outlined above, further elucidation of the water quality/chemistry and water quantity/hydrological requirements of water dependent habitats and species is needed, and this will take time, monitoring effort, and close co-operation between the relevant agencies to develop. In addition there are site specific issues and requirements, particularly for habitats. Current research (as yet unpublished) on turloughs tends to indicate that each of the study sites has unique characteristics, although certain land use and management protocols may well be widely applicable. It is difficult to set targets for water quality/chemistry that will apply across the national range of individual Habitats Directive Annex 1 listed habitats, and it may not be appropriate to set such targets nationally since it is an objective of the Habitats Directive to maintain the range of natural variation; in this sense “one size does not fit all”. The sensitivities of habitats and species are known, however, so it is still possible to identify the most sensitive receptors in a catchment – though the ability to do this will improve as more NPWS GIS data becomes available.


This guidance adopts an interim approach which addresses the general sensitivities of water dependent habitats and species to direct impacts, hydrological impacts, and water pollution. Tables included in this Section indicate the relative sensitivities of habitats (Table 5.1) and species (Table 5.3) to hydrological impacts and water pollution aspects of water status, based on best expert opinion. The tables include comments on issues that should be considered by agencies involved in implementing the Water Framework Directive, when considering existing pressures and risk assessments, and preparing and implementing River Basin Management Plans. These tables are also intended to give guidance on issues that should be considered by Competent Authorities when preparing, or responding to, plans, projects and proposals which could have an impact of sites designated for nature conservation, and to provide an indication of the types of information that developers should be required to provide.
Table 5.2 considers the relative sensitivities of Annex 1 listed water dependent habitats to nitrogen, with reference to the critical loads for Nitrogen, which are given for some habitats. These are taken from, and adapted from, Table 10.1 of Empirical nitrogen critical loads for natural and semi-natural ecosystems: 2002 update (Roland Bobbink, Mike Ashmore, Sabine Braun, Walter Flückiger and Isabel J.J. Van den Wyngaert. This is the backing document for critical nitrogen loadings under the Gothenberg Protocol, and as such relates to N deposition from air emissions, and may not be directly applicable for the purposes of the Water Framework Directive, although it is based on the ecological effects of nitrogen on plant communities (e.g. increased grass cover, decreased cover of moss flora, loss of sensitive species). It is recognised that nitrogen loadings to ecosystems are derived through a number of pathways, including air-borne (e.g. air emissions, aerial application of fertiliser and slurry spreading), water-borne (surface and ground), and past and present land use and management including inputs from grazing animals. The ecological effects of these loadings are mediated through variations in acid neutralising capacity, soil nutrient availability, and soil factors including wetness, which influence the nitrification potential, nitrogen immobilisation and denitrification rates.
Some of the research on which the critical loads for Nitrogen are based has been carried out in Ireland, but most of it has been carried out in areas where deposition from air is a) the main source of Nitrogen loadings to habitats, and/or b) rates of deposition from air are many times higher than those encountered in Ireland.
The critical N loads are suggested as interim guidance for nitrogen loadings from all pathways, which will require on-going review in the light of establishment of baseline information and monitoring trends. They are included because they give an indication of the relative sensitivities of protected habitats to Nitrogen loading. They indicate a threshold level, above which adverse impacts on the more sensitive plant species associated with individual habitats (e.g. mosses), and on plant community species composition and structure, have been found to occur in the studies reviewed in Bobbink et al (2002). Critical N loads are used in the NRA Guidelines on the Treatment of Air Quality During the Planning and Construction of National Road Schemes.

Table 5.1. Sensitivity of Habitats Directive Annex I water-dependent habitats. The sensitivity of habitats refers to existing pressures as well to developments that may be considered in the future. Water dependency indicates whether the habitat receives water from or is otherwise supported by surface water (SW), marine water (MW) or groundwater (GW). The hydrological and water pollution pressures likely to impact on each habitat, and for which measures may be required under the WFD, are listed. The likely sources or drivers are also indicated. The sensitivity of the habitats (Receptor Sensitivity) to these pressures is listed as low, medium (Med.) or high. The “Impact Potential” column is an attempt to indicate the likely impact given the sensitivity of the receptor and nature of the pathway. Note that Appropriate Assessments are required for any plans of projects potentially impacting on Natura 2000 sites, in consultation with NPWS.


HD Habitat Code

Habitat Name

Water dependency

Hydrological Impacts

Water Pollution12













Pressure (and likely driver)

Receptor Sensitivity

Impact Potential

Pressure (and likely driver)

Receptor Sensitivity

Impact Potential


Comments

1110

Sandbanks which are slightly covered by sea water all the time

MW

Changes in sediment deposition arising from current changes (coastal and marine constructions)

High

Low

Nutrient enrichment N (diffuse and point-source nutrient pollution)

Med.?

Low

Potential impacts on marine mammals and water birds

1130

Estuaries

SW, MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, temporary structures, e.g. coffer dams, dredging) and changes in salinity gradients/water mixing as a result of u/s abstractions (including seasonal changes)

Med.

Low-Med.

Nutrient enrichment N and P(diffuse and point-source nutrient pollution)

High

High

Potential conflict between conservation interests where significant wintering waterfowl populations are present, since these depend on high biomass of macroinvertebrate fauna tolerant of nutrient enrichment. Disturbance impacts on wintering waterfowl may require seasonal constraints on construction



















BOD (diffuse and point-source organic pollution)

High

Low-Med.

1140

Mudflats and sandflats not covered by seawater at low tide

MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, temporary structures, e.g. coffer dams, dredging)

High

Med.-High

Nutrient enrichment N (diffuse and point-source nutrient pollution)

Med.

Med.

1150

Coastal lagoons

SW, GW, MW

Changes in salinity and water levels (abstractions and changes to barriers)

High

High

Nutrient enrichment N and P(diffuse and point-source nutrient pollution)

High

High

Sensitivity to direct impacts likely to vary with morphological type



















BOD (diffuse and point-source organic pollution)

High

High




1160

Large shallow inlets and bays

SW, MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

Low-Med.

Low

Nutrient enrichment N (diffuse and point-source nutrient pollution)

High

Med.-High




1170

Reefs

MW

Changes in flow through reef as a result of current changes (coastal and marine constructions).

Low-Med.

Low

Nutrient enrichment N (diffuse and point-source nutrient pollution)

Med.

Low-Med.

Biogenic reef re-colonisation time may exceed 7 years following construction impacts



















BOD (diffuse and point-source organic pollution)

Med.

Low-Med.




1210

Annual vegetation of drift lines

MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

High

Med.-High

N/A

N/A

N/A




1220

Perennial vegetation of stony banks

MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

High

Med.-High

N/A

N/A

N/A




1230

Vegetated sea cliffs of the Atlantic and Baltic coasts

MW

Erosion from current changes (coastal and marine constructions) [soft coastlines only]

Low

Low

N/A

N/A

N/A

Coastal protection works at sedimentary cliffs may affect sediment transport and replenishment at other sites

1310

Salicornia and other annuals colonizing mud and sand

MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

High

Med.-High

Nutrient enrichment N (diffuse and point-source nutrient pollution)

Med.

Low




1330

Atlantic salt meadows (Glauco-Puccinellietalia maritimae)

GW, MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

High

Med.-High

Nutrient enrichment N (diffuse and point-source nutrient pollution)

Med.

Low

Land use pressures including over-grazing

1410

Mediterranean salt meadows (Juncetalia maritimi)

GW, MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

High

Med.-High

Nutrient enrichment N (diffuse and point-source nutrient pollution)

Med.

Low

Land use pressures including over-grazing

1420

Mediterranean and thermo-Atlantic halophilous scrubs (Sarcocornetea fruticosi)

MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

High

Med.-High

Nutrient enrichment N (diffuse and point-source nutrient pollution)

Med.

Low

Land use pressures including over-grazing

2110

Embryonic shifting dunes

MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

High

Med.-High

N/A

N/A

N/A

On-going direct impacts can inhibit embryonic dune formation

2120

Shifting dunes along the shoreline with Ammophila arenaria (white dunes)

MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

High

Med.-High

N/A

N/A

N/A

On-going direct impacts reduce vegetation cover and increase erosion risk

2130

Fixed coastal dunes with herbaceous vegetation (grey dunes)

MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

High

Med.-High

N/A

N/A

N/A

On-going direct impacts reduce vegetation cover and increase erosion risk

2140

Decalcified fixed dunes with Empetrum nigrum

MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

High

Med.-High

N/A

N/A

N/A




2150

Atlantic decalcified fixed dunes (Calluno-Ulicetea)

MW

Changes in sediment deposition arising from current changes (coastal and marine constructions, dredging)

High

Med.-High

N/A

N/A

N/A




2170

Dunes with Salix repens ssp. argentea (Salix arenariae)

MW, GW

Water level changes (groundwater abstractions)

High

High

Nutrient enrichment N and P of groundwater (diffuse and point-source nutrient pollution)

Med.

Low













Erosion of dune system through current changes (coastal and marine constructions, dredging)

Med.

Med.













2190

Humid dune slacks

GW, MW

Water level changes (groundwater abstractions)

High

High

Nutrient enrichment N and P of groundwater (diffuse and point-source nutrient pollution)

Med.-High

Med.-High

Cross-refer to protected species presence and sensitivities










Erosion of dune system through current changes (coastal and marine constructions, dredging)

High

Med.-High













21A0

Machairs (* in Ireland)

SW, GW, MW

Water level changes (groundwater abstractions)

High

High

Nutrient enrichment N and P of groundwater (diffuse and point-source nutrient pollution)

High

Med.-High

Cross-refer to protected species presence and sensitivities, including breeding wading birds










Erosion of dune system through current changes (coastal and marine constructions, dredging)

Med.

Low-Med.













3110

Oligotrophic waters containing very few minerals of sandy plains (Littorelletalia uniflorae)

SW, GW

Changes in water levels (abstractions, drainage)

High

High

Nutrient enrichment P (dissolved and particulate) and possibly N (diffuse and point-source nutrient pollution)

High

High

Dystrophic lake conditions can arise artificially in 3110 and maybe 3130 lakes due to forestry pressures (acidification). Direct impacts potentially high for protected species including birds, and fish stocks including Arctic char. Lake shore and bed topography relevant, wetland habitats near lake margins may include ground water dependent features vulnerable to abstraction pressures. Alien species issues.










Current changes (marinas, piers, other constructions)

Low

Low










3130

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

SW, GW

Changes in water levels (abstractions, drainage)

High

High

Nutrient enrichment P (dissolved and particulate) and possibly N (diffuse and point-source nutrient pollution)

High

High










Current changes (marinas, piers, other constructions)

Low

Low













3140

Hard oligo-mesotrophic waters with benthic vegetation of Chara spp.

SW, GW

Changes in water levels (abstractions, drainage)

High

High

Nutrient enrichment P (dissolved and particulate) and possibly N (diffuse and point-source nutrient pollution)

High

High

Alien species issues










Current changes (marinas, piers, other constructions)

Low

Low













3150

Natural eutrophic lakes with Magnopotamion or Hydrocharition-type vegetation

SW, GW

Changes in water levels (abstractions, drainage)

High

High

Nutrient enrichment P (dissolved and particulate) and possibly N (diffuse and point-source nutrient pollution)

Med.

Med.

Some of these sites are also designated for wintering and/or breeding waterfowl and disturbance issues may also arise










Current changes (marinas, piers, other constructions)

Low

Low













3160

Natural dystrophic lakes and ponds

SW, GW

Changes in water levels (abstractions, drainage)

High

High

Nutrient enrichment P (dissolved and particulate) and possibly N (diffuse and point-source nutrient pollution)

High

High

pH naturally in the range 3-6










Current changes (marinas, piers, other constructions)

Low

Low













3180

Turloughs

SW, GW

Changes in hydroperiod, water depth, flooding frequency, area or timing (arterial drainage, local drainage, abstraction in zone of contribution)

High

High

Nutrient enrichment N and particularly P (both dissolved and particulate) of groundwater (diffuse and point-source nutrient pollution)

Med.-High

Med.-High

Karst flow typology relevant. Wide variation in natural trophic status of turloughs. Activities in turlough basins may be a risk to groundwater status.

3260

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

SW, GW

Upland: Siltation and scouring as a result of changes in fluvial dynamics (catchment drainage and other landuse changes); Lowland: Changes in fluvial dynamics (erosion and deposition) (catchment drainage, river drainage, abstractions, barriers and other constructions)

High

High

Nutrient enrichment P (dissolved and particulate) and possibly N (diffuse and point-source nutrient pollution)

Med.-High

Med.-High

Sensitivity varies with protected species presence. Water status including silt load critical for Margaritifera populations, salmonid fish somewhat less sensitive but require high status, crayfish moderately sensitive. Seasonal constraints on construction for fish and crayfish



















BOD (diffuse and point-source organic pollution

Med.-High

Med.-High




3270

Rivers with muddy banks with Chenopodion rubri p.p. and Bidention p.p. vegetation

SW, GW

Changes in flood frequency and duration (arterial drainage, barriers, etc.)

High

High

Nutrient enrichment P (dissolved and particulate) and possibly N (diffuse and point-source nutrient pollution)

Low

Low

Naturally eutrophic (i.e. EPA mesotrophic) habitat mostly confined to turlough basins

4010

Northern Atlantic wet heaths with Erica tetralix (FLUSHES ONLY)

GW

Changes in groundwater flows (abstractions)

High

Low

Nutrient enrichment N of groundwater (diffuse and point-source nutrient pollution)

High

Low






















Nutrient enrichment P of groundwater (diffuse and point-source nutrient pollution)

High

Med.




6410

Molinia meadows on calcareous, peaty or clavey-silt-laden soils (Molinion caeruleae)

GW

Hydrological change

?

?

Nutrient enrichment

Medium?

?

Habitat not well know - can be associated with fluctuating water table, often with seasonal flooding in lowland sites. Montane examples are wet all year and not affected by fluctuations

6430

Hydrophilous tall herb fringe communities of plains and of the montane to alpine levels

SW, GW

Changes in flood frequency and duration (arterial drainage, barriers, etc.)

Med.

Med.

Nutrient enrichment P (dissolved and particulate) and N (diffuse and point-source nutrient pollution)

Low

Low

Habitat associated with seasonal flooding, excess nutrients likely to alter species composition towards reed-swamp. Montane examples less liable to seasonal flooding

7110

Active raised bogs (LAGG AND SUPPORT FUNCTION)

SW, GW

Changes in groundwater levels (arterial drainage and abstractions – regional level impacts)

High

High

Nutrient enrichment N of groundwater (diffuse and point-source nutrient pollution)

High

Low-Med.






















Nutrient enrichment P of groundwater (diffuse and point-source nutrient pollution)

High

Low-Med.




7120

Degraded raised bogs still capable of natural regeneration (LAGG AND SUPPORT FUNCTION)

SW, GW

Changes in groundwater levels (arterial drainage and abstractions – regional level impacts)

High

High

Nutrient enrichment N of groundwater (diffuse and point-source nutrient pollution)

High

Low-Med.






















Nutrient enrichment P of groundwater (diffuse and point-source nutrient pollution)

High

Low-Med.




7130

Blanket bog (*active only) (FLUSHES ONLY)

GW

Changes in groundwater flows (abstractions)

High

Low

Nutrient enrichment N of groundwater (diffuse and point-source nutrient pollution)

High

Low






















Nutrient enrichment P of groundwater (diffuse and point-source nutrient pollution)

High

Med.




7140

Transition mires and quaking bogs

SW, GW

Changes in groundwater levels and head (abstractions and arterial drainage)

High

High

Nutrient enrichment N of groundwater (diffuse and point-source nutrient pollution)

High

Low-Med.






















Nutrient enrichment P of groundwater (diffuse and point-source nutrient pollution)

High

Low-Med.




7150

Depressions on peat substrates of the Rhynchosporion (WET HEATH ONLY)

SW, GW

Changes in groundwater levels (abstractions)

Low

Low

N/A

N/A

N/A




7210

Calcareous fens with Cladium mariscus and species of the Caricion davallianae

GW

Changes in groundwater levels and flows (abstractions and arterial drainage)

High

High

Nutrient enrichment N of groundwater (diffuse and point-source nutrient pollution)

High

Med.

Water level optimal range from 15cm below to 40cm above ground surface



















Nutrient enrichment P of groundwater (diffuse and point-source nutrient pollution)

High

Med.




7220

Petrifying springs with tufa formation (Cratoneurion)

GW

Changes in groundwater levels and flows (abstractions and arterial drainage)

High

High

Nutrient enrichment N of groundwater (diffuse and point-source nutrient pollution)

High

High

Vertigo geyeri an indicator of good habitat structure and function



















Nutrient enrichment P of groundwater (diffuse and point-source nutrient pollution)

High

Med.




7230

Alkaline fens

GW

Changes in groundwater levels and flows (abstractions and arterial drainage)

High

High

Nutrient enrichment N of groundwater (diffuse and point-source nutrient pollution)

High

Med.

Water level more than 10cm below ground surface sub-optimal



















Nutrient enrichment P of groundwater (diffuse and point-source nutrient pollution)

High

Med.




8310

Caves not open to the public

GW

Changes in groundwater flows, increased water levels, flood frequency and/or sediment concentrations (drainage of surface water catchment, other landuse changes)

Med.

Low

N/A

N/A

N/A

Hydrology potentially important in bat hibernation roost caves

8330

Submerged or partly submerged sea caves

MW

N/A

N/A

N/A

?

?

?




91D0

Bog woodland

GW

Changes in groundwater level (abstractions and arterial drainage)

High

High

Where there is direct GW contribution: Nutrient enrichment N of groundwater (diffuse and point-source nutrient pollution)

Med.

Low

Ground flora sensitive to elevated nutrient levels particularly where moss flora is well developed. Tree growth affected by hydrological pressures which result in severe fluctuations in water levels



















Where there is direct GW contribution: Nutrient enrichment P of groundwater (diffuse and point-source nutrient pollution)

High

Med.-High




91E0

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

SW, GW

Changes in surface water flows and flooding regime (arterial drainage, abstractions, barriers etc.)

High

High

Nutrient enrichment N and P of surface water (diffuse and point-source nutrient pollution)

Low

Low-Med.













Changes in groundwater levels

Med.-High

Med.

Nutrient enrichment N and P of groundwater (diffuse and point-source nutrient pollution)

High

Med.



Water level ranges for Calcareous fen with Cladium mariscus, and for Alkaline fen, are taken from Curtis, Downes and Ní Chatháin (2006). Note that local drainage (i.e. drainage that does not fall within the scope of OPW drainage schemes, or Local Authority Drainage Districts) can have significant impacts on water dependent habitats. New plans and projects incorporating land drainage elements therefore need careful consideration and appropriate assessment.

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