1. Water Bodies Shannon Pilot River Basin
Garrett Kilroy
EPA Research Fellow
Shannon PRB
Environmental Protection
Agency
Trinity College Dublin
Funded under the ERTDI Programme
National Development Plan

2. Overview PRB Characteristics Identification of Water Bodies
Groundwater Bodies
Identification
Aggregation
Surface Water Body
Issues with pressure thresholds
Conclusions

3. River Basin Districts in Ireland WFD Co-ordination Group
“Managing Our Shared Waters”
Joint North/South consultation document, published by Department of Environment, Northern Ireland and Department of Environment, Heritage and Local Government, Republic of Ireland
Proposal for eight RBDs including three IRBDs
North-South Technical Advisory Group
UK-TAG

4. Shannon PRB Surface Waters
Summary Statistics:
18000 km2 land area
Largest RB in Ireland
Shannon River 260 km
1480 km2 TW+CW
Ecoregion 17 (Rr + Lk)
Ecoregion 1 (Tw + Cw)
6 km2 in Northern Ireland
Source: EPA

5. Shannon PRB Land Cover Agriculture is the principal activity
Significant Peatlands areas

6. Shannon PRB Rock Units Carboniferous rocks dominate
Pure bedded limestones in upper catchment
Namurian shales & sandstones in lower reaches
Geological Survey of Ireland

7. Guidance on identification of groundwater bodies

8. Groundwater Body Delineation

9. Groundwater Body Delineation
Step1:
Produce a seamless geological map at 1:100,000 scale
Combine rock units into some 28 Rock Unit Groups anticipated to have similar hydrogeological properties

11. Groundwater Body Delineation
Step2:
Rock Unit Groups are assigned one or more of Eight Aquifer Classes:
Regionally Important Aquifers:
Karstic aquifers with predominantly conduit flow (Rkc)
Karstic aquifers with predominantly diffuse flow (Rkd)
Fissured aquifer (Rf)
Locally Important Aquifers:
Bedrock: generally moderately productive (Lm)
Bedrock: moderately productive only in local zones (Ll)
Poor Aquifers:
Bedrock: generally unproductive except for local zones (PI)
Bedrock: generally unproductive (Pu)
Sand & Gravel Aquifers (Rg Lg)

12. 2. Aquifer Classification Map (Draft)
Hydrometric Area 24
2. Aquifer Classification Map (Draft)
Geological Survey of Ireland

13. Groundwater Body Delineation
Step 3 :
The Aquifers Classes are grouped into 4 Types based on similar groundwater flow regimes:
Karstic aquifers
Gravel Aquifers
Productive fractured bedrock aquifers
Poorly productive bedrock aquifers

15. Groundwater Body Delineation
Step 4 :
Preliminary groundwater bodies are delineated using the following hierarchy:
No flow, or relatively low flow, geological boundaries
Boundaries based on groundwater highs, differing flow systems and flow lines
Final groundwater bodies are delineated incorporating surface water catchment boundaries
Exceptions where the influence of topography on groundwater flow is diminished:
Karstic aquifers
Confined aquifers

16. 4.

17. Small GWBs For small GWBs there are two responses:
Incorporate a small area of one aquifer into a larger one if the flow system and continuity not disrupted
Remain a small hydrogeologically significant GWB if:
There is ecosystem dependency
Provides groundwater supply
There is a significant impact on the flow system

18. Summary Statistics 97 (+/-) Groundwater Bodies Median size = 53 km2
Max size = 1400 km2
Min size = 5 km2
Geological Survey of Ireland

19. Initial Characterisation Geological Survey of Ireland
Source report and SPA
EPA hydrochemistry data
Specific dry weather flow
EPA groundwater level
OSI 1:50K rivers & streams
Mapped bedrock faults
Outline of GWB
Geological Survey of Ireland

20. Guidance on identification of surface water bodies

21. Rivers & Lakes Water bodies must be a “discrete & significant element”
of one category
of same type
contiguous
Must not overlap with other surface water bodies

22. Guidance on Small Water Body Elements
Aggregation possible if:
same category
same type
contiguous

23. Potential River WBs in Shannon
Typology:
Peat cover (2)
Geology (2)
Flow (4)
Slope (4)
Nenagh sub catchment
326 km2
17 water bodies
AGGREGATION
REQUIRED
Shannon PRB
18000 km2
c water bodies
Source: EPA

24. Potential River WBs in Shannon
Grouping by type
17 reduces to 10
Allow discontiguity
17 reduces to 7
Potential halving of river WBs to 500 in Shannon RB
Source: EPA

25. Lake Network Typology being developed System B 1688 digitized lakes
Only fifty lakes > 0.5 km2
97% < 0.5 km2
Aggregation required

26. Possible approach for small lakes
Monitor and report on fifty lakes > 0.5 km2
Monitor lakes <0.5 km2 if protected area or impacted
Aggregate other small lakes on a sub-catchment basis
Monitor and report in each sub-catchment on representative lakes of:
Same type
Same pressures
Same status
But not contiguous

27. Transitional & Coastal Waters
Six Ecoregions
Atlantic Ocean
Norwegian Sea
Barents Sea
North Sea
Baltic Sea
Mediterranean Sea

28. ECOREGION 1 Joint UK & Ireland typology SNIFFER research project
Scottish Northern Ireland Forum for Environmental Research

29. Coastal and Transitional Water Bodies

30. Summary Preliminary Water body Identification in Shannon PRB
Category
Number of WBs
Groundwater
97 +/-
Rivers
c.1100 (aggregation required)
Lakes
50 (+18 sub-catchments)
Transitional 13
Coastal 9
Requires (biological) validation + pressures assessment

31. Issues with pressure thresholds
Good Information on State of Quality Element or Indicative Parameter?
Yes No
Direct
Assessment
Indirect
Assessment No
Screening
Pressures Present
Yes
State Data
Comparison with
Objectives
Modelling
Prediction
Yes No
Not at Risk
Uncertain
At Risk
Source: James Hunt, Pre Accession Adviser (EU PHARE)

32. Shannon PRB Approach Often lack of monitoring data
Reliance on pressures assessment
Relate status to pressure thresholds
Boundaries +
Conceptual Understanding
Description
Water Body Delineation
Source
Pressures
Loading
Spatial location
Relevant Characteristics of overground and underground Pathways
(susceptibility)
Relevant Characteristics of Receptor
(sensitivity)
Monitoring data
Information on known impacts
Risk Assessment
Risk Assessment
Potentially
at risk
Further Characterisation
Not at risk
At risk

33. Conclusions Small Water Bodies Pressure thresholds
Requires a transparent, consistent and pragmatic rationale
Contiguity not always useful
Pressure thresholds
Must take account of conceptual understanding of water body
Provide more effective and defensible programme of measures

34. Thank you!